2024-04-05 11:53:34

by Jens Wiklander

[permalink] [raw]
Subject: [PATCH v4 0/3] Replay Protected Memory Block (RPMB) subsystem

Hi,

This patch set introduces a new RPMB subsystem, based on patches from [1],
[2], and [3]. The RPMB subsystem aims at providing access to RPMB
partitions to other kernel drivers, in particular the OP-TEE driver. A new
user space ABI isn't needed, we can instead continue using the already
present ABI when writing the RPMB key during production.

I've added and removed things to keep only what is needed by the OP-TEE
driver. Since the posting of [3], there has been major changes in the MMC
subsystem so "mmc: block: register RPMB partition with the RPMB subsystem"
is in practice completely rewritten.

With this OP-TEE can access RPMB during early boot instead of having to
wait for user space to become available as in the current design [4].
This will benefit the efi variables [5] since we wont rely on userspace as
well as some TPM issues [6] that were solved.

The OP-TEE driver finds the correct RPMB device to interact with by
iterating over available devices until one is found with a programmed
authentication matching the one OP-TEE is using. This enables coexisting
users of other RPMBs since the owner can be determined by who knows the
authentication key.

The corresponding secure world OP-TEE patches are available at [7].

I've put myself as a maintainer for the RPMB subsystem as I have an
interest in the OP-TEE driver to keep this in good shape. However, if you'd
rather see someone else taking the maintainership that's fine too. I'll
help keep the subsystem updated regardless.

[1] https://lore.kernel.org/lkml/[email protected]/
[2] https://lore.kernel.org/lkml/[email protected]/
[3] https://lore.kernel.org/linux-mmc/[email protected]/
[4] https://optee.readthedocs.io/en/latest/architecture/secure_storage.html#rpmb-secure-storage
[5] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c44b6be62e8dd4ee0a308c36a70620613e6fc55f
[6] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7269cba53d906cf257c139d3b3a53ad272176bca
[7] https://github.com/jenswi-linaro/optee_os/tree/rpmb_probe

Thanks,
Jens

Changes since v3:
* Move struct rpmb_frame into the MMC driver since the format of the RPMB
frames depend on the implementation, one format for eMMC, another for
UFS, and so on
* "rpmb: add Replay Protected Memory Block (RPMB) subsystem"
- Adding Reviewed-by: Linus Walleij <[email protected]>
- Adding more description of the API functions
- Removing the set_dev_info() op from struct rpmb_ops, the needed information
is supplied in the arguments to rpmb_dev_register() instead.
- Getting rid of struct rpmb_ops since only the route_frames() op was
remaining, store that op directly in struct rpmb_dev
- Changed rpmb_interface_register() and rpmb_interface_unregister() to use
notifier_block instead of implementing the same thing ourselves
* "mmc: block: register RPMB partition with the RPMB subsystem"
- Moving the call to rpmb_dev_register() to be done at the end of
mmc_blk_probe() when the device is fully available
* "optee: probe RPMB device using RPMB subsystem"
- Use IS_REACHABLE(CONFIG_RPMB) to determine if the RPMB subsystem is
available
- Translate TEE_ERROR_STORAGE_NOT_AVAILABLE if encountered in get_devices()
to recognize the error in optee_rpmb_scan()
- Simplified optee_rpmb_scan() and optee_rpmb_intf_rdev()

Changes since v2:
* "rpmb: add Replay Protected Memory Block (RPMB) subsystem"
- Fixing documentation issues
- Adding a "depends on MMC" in the Kconfig
- Removed the class-device and the embedded device, struct rpmb_dev now
relies on the parent device for reference counting as requested
- Removed the now unneeded rpmb_ops get_resources() and put_resources()
since references are already taken in mmc_blk_alloc_rpmb_part() before
rpmb_dev_register() is called
- Added rpmb_interface_{,un}register() now that
class_interface_{,un}register() can't be used ay longer
* "mmc: block: register RPMB partition with the RPMB subsystem"
- Adding the missing error cleanup in alloc_idata()
- Taking the needed reference to md->disk in mmc_blk_alloc_rpmb_part()
instead of in mmc_rpmb_chrdev_open() and rpmb_op_mmc_get_resources()
* "optee: probe RPMB device using RPMB subsystem"
- Registering to get a notification when an RPMB device comes online
- Probes for RPMB devices each time an RPMB device comes online, until
a usable device is found
- When a usable RPMB device is found, call
optee_enumerate_devices(PTA_CMD_GET_DEVICES_RPMB)
- Pass type of rpmb in return value from OPTEE_RPC_CMD_RPMB_PROBE_NEXT

Changes since Shyam's RFC:
* Removed the remaining leftover rpmb_cdev_*() function calls
* Refactored the struct rpmb_ops with all the previous ops replaced, in
some sense closer to [3] with the route_frames() op
* Added rpmb_route_frames()
* Added struct rpmb_frame, enum rpmb_op_result, and enum rpmb_type from [3]
* Removed all functions not needed in the OP-TEE use case
* Added "mmc: block: register RPMB partition with the RPMB subsystem", based
on the commit with the same name in [3]
* Added "optee: probe RPMB device using RPMB subsystem" for integration
with OP-TEE
* Moved the RPMB driver into drivers/misc/rpmb-core.c
* Added my name to MODULE_AUTHOR() in rpmb-core.c
* Added an rpmb_mutex to serialize access to the IDA
* Removed the target parameter from all rpmb_*() functions since it's
currently unused

Jens Wiklander (3):
rpmb: add Replay Protected Memory Block (RPMB) subsystem
mmc: block: register RPMB partition with the RPMB subsystem
optee: probe RPMB device using RPMB subsystem

MAINTAINERS | 7 +
drivers/misc/Kconfig | 10 ++
drivers/misc/Makefile | 1 +
drivers/misc/rpmb-core.c | 232 +++++++++++++++++++++++++++++
drivers/mmc/core/block.c | 230 ++++++++++++++++++++++++++++-
drivers/tee/optee/core.c | 30 ++++
drivers/tee/optee/device.c | 7 +
drivers/tee/optee/ffa_abi.c | 8 +
drivers/tee/optee/optee_private.h | 21 ++-
drivers/tee/optee/optee_rpc_cmd.h | 35 +++++
drivers/tee/optee/rpc.c | 233 ++++++++++++++++++++++++++++++
drivers/tee/optee/smc_abi.c | 7 +
include/linux/rpmb.h | 136 +++++++++++++++++
13 files changed, 954 insertions(+), 3 deletions(-)
create mode 100644 drivers/misc/rpmb-core.c
create mode 100644 include/linux/rpmb.h

--
2.34.1



2024-04-05 11:53:44

by Jens Wiklander

[permalink] [raw]
Subject: [PATCH v4 1/3] rpmb: add Replay Protected Memory Block (RPMB) subsystem

A number of storage technologies support a specialised hardware
partition designed to be resistant to replay attacks. The underlying
HW protocols differ but the operations are common. The RPMB partition
cannot be accessed via standard block layer, but by a set of specific
RPMB commands: WRITE, READ, GET_WRITE_COUNTER, and PROGRAM_KEY. Such a
partition provides authenticated and replay protected access, hence
suitable as a secure storage.

The initial aim of this patch is to provide a simple RPMB driver
interface which can be accessed by the optee driver to facilitate early
RPMB access to OP-TEE OS (secure OS) during the boot time.

A TEE device driver can claim the RPMB interface, for example, via
rpmb_interface_register() or rpmb_dev_find_device(). The RPMB driver
provides a callback to route RPMB frames to the RPMB device accessible
via rpmb_route_frames().

The detailed operation of implementing the access is left to the TEE
device driver itself.

Signed-off-by: Tomas Winkler <[email protected]>
Signed-off-by: Alex Bennée <[email protected]>
Signed-off-by: Shyam Saini <[email protected]>
Signed-off-by: Jens Wiklander <[email protected]>
Reviewed-by: Linus Walleij <[email protected]>
---
MAINTAINERS | 7 ++
drivers/misc/Kconfig | 10 ++
drivers/misc/Makefile | 1 +
drivers/misc/rpmb-core.c | 232 +++++++++++++++++++++++++++++++++++++++
include/linux/rpmb.h | 136 +++++++++++++++++++++++
5 files changed, 386 insertions(+)
create mode 100644 drivers/misc/rpmb-core.c
create mode 100644 include/linux/rpmb.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 8999497011a2..e83152c42499 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19012,6 +19012,13 @@ T: git git://linuxtv.org/media_tree.git
F: Documentation/devicetree/bindings/media/allwinner,sun8i-a83t-de2-rotate.yaml
F: drivers/media/platform/sunxi/sun8i-rotate/

+RPMB SUBSYSTEM
+M: Jens Wiklander <[email protected]>
+L: [email protected]
+S: Supported
+F: drivers/misc/rpmb-core.c
+F: include/linux/rpmb.h
+
RPMSG TTY DRIVER
M: Arnaud Pouliquen <[email protected]>
L: [email protected]
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 4fb291f0bf7c..dbff9e8c3a03 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -104,6 +104,16 @@ config PHANTOM
If you choose to build module, its name will be phantom. If unsure,
say N here.

+config RPMB
+ tristate "RPMB partition interface"
+ depends on MMC
+ help
+ Unified RPMB unit interface for RPMB capable devices such as eMMC and
+ UFS. Provides interface for in-kernel security controllers to access
+ RPMB unit.
+
+ If unsure, select N.
+
config TIFM_CORE
tristate "TI Flash Media interface support"
depends on PCI
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index ea6ea5bbbc9c..8af058ad1df4 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_LKDTM) += lkdtm/
obj-$(CONFIG_TIFM_CORE) += tifm_core.o
obj-$(CONFIG_TIFM_7XX1) += tifm_7xx1.o
obj-$(CONFIG_PHANTOM) += phantom.o
+obj-$(CONFIG_RPMB) += rpmb-core.o
obj-$(CONFIG_QCOM_COINCELL) += qcom-coincell.o
obj-$(CONFIG_QCOM_FASTRPC) += fastrpc.o
obj-$(CONFIG_SENSORS_BH1770) += bh1770glc.o
diff --git a/drivers/misc/rpmb-core.c b/drivers/misc/rpmb-core.c
new file mode 100644
index 000000000000..5479469c26f3
--- /dev/null
+++ b/drivers/misc/rpmb-core.c
@@ -0,0 +1,232 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright(c) 2015 - 2019 Intel Corporation. All rights reserved.
+ * Copyright(c) 2021 - 2024 Linaro Ltd.
+ */
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/rpmb.h>
+#include <linux/slab.h>
+
+static struct list_head rpmb_dev_list;
+static DEFINE_MUTEX(rpmb_mutex);
+static struct blocking_notifier_head rpmb_interface =
+ BLOCKING_NOTIFIER_INIT(rpmb_interface);
+
+/**
+ * rpmb_dev_get() - increase rpmb device ref counter
+ * @rdev: rpmb device
+ */
+struct rpmb_dev *rpmb_dev_get(struct rpmb_dev *rdev)
+{
+ if (rdev)
+ get_device(rdev->parent_dev);
+ return rdev;
+}
+EXPORT_SYMBOL_GPL(rpmb_dev_get);
+
+/**
+ * rpmb_dev_put() - decrease rpmb device ref counter
+ * @rdev: rpmb device
+ */
+void rpmb_dev_put(struct rpmb_dev *rdev)
+{
+ if (rdev)
+ put_device(rdev->parent_dev);
+}
+EXPORT_SYMBOL_GPL(rpmb_dev_put);
+
+/**
+ * rpmb_route_frames() - route rpmb frames to rpmb device
+ * @rdev: rpmb device
+ * @req: rpmb request frames
+ * @req_len: length of rpmb request frames in bytes
+ * @rsp: rpmb response frames
+ * @rsp_len: length of rpmb response frames in bytes
+ *
+ * Returns: < 0 on failure
+ */
+int rpmb_route_frames(struct rpmb_dev *rdev, u8 *req,
+ unsigned int req_len, u8 *rsp, unsigned int rsp_len)
+{
+ if (!req || !req_len || !rsp || !rsp_len)
+ return -EINVAL;
+
+ return rdev->descr.route_frames(rdev->parent_dev, req, req_len,
+ rsp, rsp_len);
+}
+EXPORT_SYMBOL_GPL(rpmb_route_frames);
+
+/**
+ * rpmb_dev_find_device() - return first matching rpmb device
+ * @data: data for the match function
+ * @match: the matching function
+ *
+ * Iterate over registered RPMB devices, and call @match() for each passing
+ * it the RPMB device and @data.
+ *
+ * The return value of @match() is checked for each call. If it returns
+ * anything other 0, break and return the found RPMB device.
+ *
+ * It's the callers responsibility to call rpmb_dev_put() on the returned
+ * device, when it's done with it.
+ *
+ * Returns: a matching rpmb device or NULL on failure
+ */
+struct rpmb_dev *rpmb_dev_find_device(const void *data,
+ const struct rpmb_dev *start,
+ int (*match)(struct rpmb_dev *rdev,
+ const void *data))
+{
+ struct rpmb_dev *rdev;
+ struct list_head *pos;
+
+ mutex_lock(&rpmb_mutex);
+ if (start)
+ pos = start->list_node.next;
+ else
+ pos = rpmb_dev_list.next;
+
+ while (pos != &rpmb_dev_list) {
+ rdev = container_of(pos, struct rpmb_dev, list_node);
+ if (match(rdev, data)) {
+ rpmb_dev_get(rdev);
+ goto out;
+ }
+ pos = pos->next;
+ }
+ rdev = NULL;
+
+out:
+ mutex_unlock(&rpmb_mutex);
+
+ return rdev;
+}
+
+/**
+ * rpmb_dev_unregister() - unregister RPMB partition from the RPMB subsystem
+ * @rdev: the rpmb device to unregister
+ *
+ * This function should be called from the release function of the
+ * underlying device used when the RPMB device was registered.
+ *
+ * Returns: < 0 on failure
+ */
+int rpmb_dev_unregister(struct rpmb_dev *rdev)
+{
+ if (!rdev)
+ return -EINVAL;
+
+ mutex_lock(&rpmb_mutex);
+ list_del(&rdev->list_node);
+ mutex_unlock(&rpmb_mutex);
+ kfree(rdev->descr.dev_id);
+ kfree(rdev);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(rpmb_dev_unregister);
+
+/**
+ * rpmb_dev_register - register RPMB partition with the RPMB subsystem
+ * @dev: storage device of the rpmb device
+ * @ops: device specific operations
+ *
+ * While registering the RPMB partition extract needed device information
+ * while needed resources are available.
+ *
+ * Returns: a pointer to a 'struct rpmb_dev' or an ERR_PTR on failure
+ */
+struct rpmb_dev *rpmb_dev_register(struct device *dev,
+ struct rpmb_descr *descr)
+{
+ struct rpmb_dev *rdev;
+
+ if (!dev || !descr || !descr->route_frames || !descr->dev_id ||
+ !descr->dev_id_len)
+ return ERR_PTR(-EINVAL);
+
+ rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
+ if (!rdev)
+ return ERR_PTR(-ENOMEM);
+ rdev->descr = *descr;
+ rdev->descr.dev_id = kmemdup(descr->dev_id, descr->dev_id_len,
+ GFP_KERNEL);
+ if (!rdev->descr.dev_id) {
+ kfree(rdev);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ rdev->parent_dev = dev;
+
+ dev_dbg(rdev->parent_dev, "registered device\n");
+
+ mutex_lock(&rpmb_mutex);
+ list_add_tail(&rdev->list_node, &rpmb_dev_list);
+ blocking_notifier_call_chain(&rpmb_interface, RPMB_NOTIFY_ADD_DEVICE,
+ rdev);
+ mutex_unlock(&rpmb_mutex);
+
+ return rdev;
+}
+EXPORT_SYMBOL_GPL(rpmb_dev_register);
+
+/**
+ * rpmb_interface_register() - register for new device notifications
+ *
+ * @nb : New entry in notifier chain
+ *
+ * Returns: 0 on success -EEXIST on error.
+ */
+int rpmb_interface_register(struct notifier_block *nb)
+{
+ struct rpmb_dev *rdev;
+ int ret;
+
+ ret = blocking_notifier_chain_register(&rpmb_interface, nb);
+ if (ret)
+ return ret;
+
+ mutex_lock(&rpmb_mutex);
+ list_for_each_entry(rdev, &rpmb_dev_list, list_node)
+ nb->notifier_call(nb, RPMB_NOTIFY_ADD_DEVICE, rdev);
+ mutex_unlock(&rpmb_mutex);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(rpmb_interface_register);
+
+/**
+ * rpmb_interface_unregister() - unregister from new device notifications
+ *
+ * @nb : Entry to remove from notifier chain
+ *
+ * Returns: 0 on success or -ENOENT on failure.
+ */
+int rpmb_interface_unregister(struct notifier_block *nb)
+{
+ return blocking_notifier_chain_unregister(&rpmb_interface, nb);
+}
+EXPORT_SYMBOL_GPL(rpmb_interface_unregister);
+
+static int __init rpmb_init(void)
+{
+ INIT_LIST_HEAD(&rpmb_dev_list);
+ return 0;
+}
+
+static void __exit rpmb_exit(void)
+{
+ mutex_destroy(&rpmb_mutex);
+}
+
+subsys_initcall(rpmb_init);
+module_exit(rpmb_exit);
+
+MODULE_AUTHOR("Jens Wiklander <[email protected]>");
+MODULE_DESCRIPTION("RPMB class");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/rpmb.h b/include/linux/rpmb.h
new file mode 100644
index 000000000000..251d6b7e6d15
--- /dev/null
+++ b/include/linux/rpmb.h
@@ -0,0 +1,136 @@
+/* SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 */
+/*
+ * Copyright (C) 2015-2019 Intel Corp. All rights reserved
+ * Copyright (C) 2021-2022 Linaro Ltd
+ */
+#ifndef __RPMB_H__
+#define __RPMB_H__
+
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/notifier.h>
+
+/**
+ * enum rpmb_type - type of underlying storage technology
+ *
+ * @RPMB_TYPE_EMMC : emmc (JESD84-B50.1)
+ * @RPMB_TYPE_UFS : UFS (JESD220)
+ * @RPMB_TYPE_NVME : NVM Express
+ */
+enum rpmb_type {
+ RPMB_TYPE_EMMC,
+ RPMB_TYPE_UFS,
+ RPMB_TYPE_NVME,
+};
+
+/**
+ * struct rpmb_descr - RPMB descriptor provided by the underlying block device
+ *
+ * @type : block device type
+ * @route_frames : routes frames to and from the RPMB device
+ * @dev_id : unique device identifier read from the hardware
+ * @dev_id_len : length of unique device identifier
+ * @reliable_wr_count: number of sectors that can be written in one access
+ * @capacity : capacity of the device in units of 128K
+ *
+ * @dev_id is intended to be used as input when deriving the authenticaion key.
+ */
+struct rpmb_descr {
+ enum rpmb_type type;
+ int (*route_frames)(struct device *dev, u8 *req, unsigned int req_len,
+ u8 *resp, unsigned int resp_len);
+ u8 *dev_id;
+ size_t dev_id_len;
+ u16 reliable_wr_count;
+ u16 capacity;
+};
+
+/**
+ * struct rpmb_dev - device which can support RPMB partition
+ *
+ * @parent_dev : parent device
+ * @list_node : linked list node
+ * @descr : RPMB descriptor
+ */
+struct rpmb_dev {
+ struct device *parent_dev;
+ struct list_head list_node;
+ struct rpmb_descr descr;
+};
+
+enum rpmb_interface_action {
+ RPMB_NOTIFY_ADD_DEVICE,
+};
+
+/**
+ * struct rpmb_interface - subscribe to new RPMB devices
+ *
+ * @list_node : linked list node
+ * @add_rdev : notifies that a new RPMB device has been found
+ */
+struct rpmb_interface {
+ struct list_head list_node;
+ void (*add_rdev)(struct rpmb_interface *intf, struct rpmb_dev *rdev);
+};
+
+#if IS_ENABLED(CONFIG_RPMB)
+struct rpmb_dev *rpmb_dev_get(struct rpmb_dev *rdev);
+void rpmb_dev_put(struct rpmb_dev *rdev);
+struct rpmb_dev *rpmb_dev_find_device(const void *data,
+ const struct rpmb_dev *start,
+ int (*match)(struct rpmb_dev *rdev,
+ const void *data));
+struct rpmb_dev *rpmb_dev_register(struct device *dev,
+ struct rpmb_descr *descr);
+int rpmb_dev_unregister(struct rpmb_dev *rdev);
+
+int rpmb_route_frames(struct rpmb_dev *rdev, u8 *req,
+ unsigned int req_len, u8 *resp, unsigned int resp_len);
+
+int rpmb_interface_register(struct notifier_block *nb);
+int rpmb_interface_unregister(struct notifier_block *nb);
+#else
+static inline struct rpmb_dev *rpmb_dev_get(struct rpmb_dev *rdev)
+{
+ return NULL;
+}
+
+static inline void rpmb_dev_put(struct rpmb_dev *rdev) { }
+
+static inline struct rpmb_dev *
+rpmb_dev_find_device(const void *data, const struct rpmb_dev *start,
+ int (*match)(struct rpmb_dev *rdev, const void *data))
+{
+ return NULL;
+}
+
+static inline struct rpmb_dev *
+rpmb_dev_register(struct device *dev, const struct rpmb_ops *ops)
+{
+ return NULL;
+}
+
+static inline int rpmb_dev_unregister(struct rpmb_dev *dev)
+{
+ return 0;
+}
+
+static inline int rpmb_route_frames(struct rpmb_dev *rdev, u8 *req,
+ unsigned int req_len, u8 *resp,
+ unsigned int resp_len)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline int rpmb_interface_register(struct notifier_block *nb)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline int rpmb_interface_unregister(struct notifier_block *nb)
+{
+ return -EOPNOTSUPP;
+}
+#endif /* CONFIG_RPMB */
+
+#endif /* __RPMB_H__ */
--
2.34.1


2024-04-05 11:53:49

by Jens Wiklander

[permalink] [raw]
Subject: [PATCH v4 2/3] mmc: block: register RPMB partition with the RPMB subsystem

Register eMMC RPMB partition with the RPMB subsystem and provide
an implementation for the RPMB access operations abstracting
the actual multi step process.

Add a callback to extract the needed device information at registration
to avoid accessing the struct mmc_card at a later stage as we're not
holding a reference counter for this struct.

Taking the needed reference to md->disk in mmc_blk_alloc_rpmb_part()
instead of in mmc_rpmb_chrdev_open(). This is needed by the
route_frames() function pointer in struct rpmb_ops.

Signed-off-by: Tomas Winkler <[email protected]>
Signed-off-by: Alexander Usyskin <[email protected]>
Signed-off-by: Jens Wiklander <[email protected]>
---
drivers/mmc/core/block.c | 230 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 228 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index 32d49100dff5..e040d4df0b6f 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -33,6 +33,7 @@
#include <linux/cdev.h>
#include <linux/mutex.h>
#include <linux/scatterlist.h>
+#include <linux/string.h>
#include <linux/string_helpers.h>
#include <linux/delay.h>
#include <linux/capability.h>
@@ -40,6 +41,7 @@
#include <linux/pm_runtime.h>
#include <linux/idr.h>
#include <linux/debugfs.h>
+#include <linux/rpmb.h>

#include <linux/mmc/ioctl.h>
#include <linux/mmc/card.h>
@@ -76,6 +78,46 @@ MODULE_ALIAS("mmc:block");
#define MMC_EXTRACT_INDEX_FROM_ARG(x) ((x & 0x00FF0000) >> 16)
#define MMC_EXTRACT_VALUE_FROM_ARG(x) ((x & 0x0000FF00) >> 8)

+/**
+ * struct rpmb_frame - rpmb frame as defined by specs
+ *
+ * @stuff : stuff bytes
+ * @key_mac : The authentication key or the message authentication
+ * code (MAC) depending on the request/response type.
+ * The MAC will be delivered in the last (or the only)
+ * block of data.
+ * @data : Data to be written or read by signed access.
+ * @nonce : Random number generated by the host for the requests
+ * and copied to the response by the RPMB engine.
+ * @write_counter: Counter value for the total amount of the successful
+ * authenticated data write requests made by the host.
+ * @addr : Address of the data to be programmed to or read
+ * from the RPMB. Address is the serial number of
+ * the accessed block (half sector 256B).
+ * @block_count : Number of blocks (half sectors, 256B) requested to be
+ * read/programmed.
+ * @result : Includes information about the status of the write counter
+ * (valid, expired) and result of the access made to the RPMB.
+ * @req_resp : Defines the type of request and response to/from the memory.
+ */
+struct rpmb_frame {
+ u8 stuff[196];
+ u8 key_mac[32];
+ u8 data[256];
+ u8 nonce[16];
+ __be32 write_counter;
+ __be16 addr;
+ __be16 block_count;
+ __be16 result;
+ __be16 req_resp;
+} __packed;
+
+#define RPMB_PROGRAM_KEY 0x1 /* Program RPMB Authentication Key */
+#define RPMB_GET_WRITE_COUNTER 0x2 /* Read RPMB write counter */
+#define RPMB_WRITE_DATA 0x3 /* Write data to RPMB partition */
+#define RPMB_READ_DATA 0x4 /* Read data from RPMB partition */
+#define RPMB_RESULT_READ 0x5 /* Read result request (Internal) */
+
static DEFINE_MUTEX(block_mutex);

/*
@@ -163,6 +205,7 @@ struct mmc_rpmb_data {
int id;
unsigned int part_index;
struct mmc_blk_data *md;
+ struct rpmb_dev *rdev;
struct list_head node;
};

@@ -2672,7 +2715,6 @@ static int mmc_rpmb_chrdev_open(struct inode *inode, struct file *filp)

get_device(&rpmb->dev);
filp->private_data = rpmb;
- mmc_blk_get(rpmb->md->disk);

return nonseekable_open(inode, filp);
}
@@ -2682,7 +2724,6 @@ static int mmc_rpmb_chrdev_release(struct inode *inode, struct file *filp)
struct mmc_rpmb_data *rpmb = container_of(inode->i_cdev,
struct mmc_rpmb_data, chrdev);

- mmc_blk_put(rpmb->md);
put_device(&rpmb->dev);

return 0;
@@ -2703,10 +2744,157 @@ static void mmc_blk_rpmb_device_release(struct device *dev)
{
struct mmc_rpmb_data *rpmb = dev_get_drvdata(dev);

+ rpmb_dev_unregister(rpmb->rdev);
+ mmc_blk_put(rpmb->md);
ida_simple_remove(&mmc_rpmb_ida, rpmb->id);
kfree(rpmb);
}

+static void free_idata(struct mmc_blk_ioc_data **idata, unsigned int cmd_count)
+{
+ unsigned int n;
+
+ for (n = 0; n < cmd_count; n++)
+ kfree(idata[n]);
+ kfree(idata);
+}
+
+static struct mmc_blk_ioc_data **alloc_idata(struct mmc_rpmb_data *rpmb,
+ unsigned int cmd_count)
+{
+ struct mmc_blk_ioc_data **idata;
+ unsigned int n;
+
+ idata = kcalloc(cmd_count, sizeof(*idata), GFP_KERNEL);
+ if (!idata)
+ return NULL;
+
+ for (n = 0; n < cmd_count; n++) {
+ idata[n] = kcalloc(1, sizeof(**idata), GFP_KERNEL);
+ if (!idata[n]) {
+ free_idata(idata, n);
+ return NULL;
+ }
+ idata[n]->rpmb = rpmb;
+ }
+
+ return idata;
+}
+
+static void set_idata(struct mmc_blk_ioc_data *idata, u32 opcode,
+ int write_flag, u8 *buf, unsigned int buf_bytes)
+{
+ idata->ic.opcode = opcode;
+ idata->ic.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
+ idata->ic.write_flag = write_flag;
+ idata->ic.blksz = sizeof(struct rpmb_frame);
+ idata->ic.blocks = buf_bytes / idata->ic.blksz;
+ idata->buf = buf;
+ idata->buf_bytes = buf_bytes;
+}
+
+static int mmc_route_rpmb_frames(struct device *dev, u8 *req,
+ unsigned int req_len, u8 *resp,
+ unsigned int resp_len)
+{
+ struct rpmb_frame *frm = (struct rpmb_frame *)req;
+ struct mmc_rpmb_data *rpmb = dev_get_drvdata(dev);
+ struct mmc_blk_data *md = rpmb->md;
+ struct mmc_blk_ioc_data **idata;
+ unsigned int cmd_count;
+ struct request *rq;
+ u16 req_type;
+ bool write;
+ int ret;
+
+ if (IS_ERR(md->queue.card))
+ return PTR_ERR(md->queue.card);
+
+ if (req_len < sizeof(*frm))
+ return -EINVAL;
+
+ req_type = be16_to_cpu(frm->req_resp);
+ switch (req_type) {
+ case RPMB_PROGRAM_KEY:
+ if (req_len != sizeof(struct rpmb_frame) ||
+ resp_len != sizeof(struct rpmb_frame))
+ return -EINVAL;
+ write = true;
+ break;
+ case RPMB_GET_WRITE_COUNTER:
+ if (req_len != sizeof(struct rpmb_frame) ||
+ resp_len != sizeof(struct rpmb_frame))
+ return -EINVAL;
+ write = false;
+ break;
+ case RPMB_WRITE_DATA:
+ if (req_len % sizeof(struct rpmb_frame) ||
+ resp_len != sizeof(struct rpmb_frame))
+ return -EINVAL;
+ write = true;
+ break;
+ case RPMB_READ_DATA:
+ if (req_len != sizeof(struct rpmb_frame) ||
+ resp_len % sizeof(struct rpmb_frame))
+ return -EINVAL;
+ write = false;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (write)
+ cmd_count = 3;
+ else
+ cmd_count = 2;
+
+ idata = alloc_idata(rpmb, cmd_count);
+ if (!idata)
+ return -ENOMEM;
+
+ if (write) {
+ struct rpmb_frame *frm = (struct rpmb_frame *)resp;
+
+ /* Send write request frame(s) */
+ set_idata(idata[0], MMC_WRITE_MULTIPLE_BLOCK,
+ 1 | MMC_CMD23_ARG_REL_WR, req, req_len);
+
+ /* Send result request frame */
+ memset(frm, 0, sizeof(*frm));
+ frm->req_resp = cpu_to_be16(RPMB_RESULT_READ);
+ set_idata(idata[1], MMC_WRITE_MULTIPLE_BLOCK, 1, resp,
+ resp_len);
+
+ /* Read response frame */
+ set_idata(idata[2], MMC_READ_MULTIPLE_BLOCK, 0, resp, resp_len);
+ } else {
+ /* Send write request frame(s) */
+ set_idata(idata[0], MMC_WRITE_MULTIPLE_BLOCK, 1, req, req_len);
+
+ /* Read response frame */
+ set_idata(idata[1], MMC_READ_MULTIPLE_BLOCK, 0, resp, resp_len);
+ }
+
+ rq = blk_mq_alloc_request(md->queue.queue, REQ_OP_DRV_OUT, 0);
+ if (IS_ERR(rq)) {
+ ret = PTR_ERR(rq);
+ goto out;
+ }
+
+ req_to_mmc_queue_req(rq)->drv_op = MMC_DRV_OP_IOCTL_RPMB;
+ req_to_mmc_queue_req(rq)->drv_op_result = -EIO;
+ req_to_mmc_queue_req(rq)->drv_op_data = idata;
+ req_to_mmc_queue_req(rq)->ioc_count = cmd_count;
+ blk_execute_rq(rq, false);
+ ret = req_to_mmc_queue_req(rq)->drv_op_result;
+
+ blk_mq_free_request(rq);
+
+out:
+ free_idata(idata, cmd_count);
+ return ret;
+}
+
static int mmc_blk_alloc_rpmb_part(struct mmc_card *card,
struct mmc_blk_data *md,
unsigned int part_index,
@@ -2741,6 +2929,7 @@ static int mmc_blk_alloc_rpmb_part(struct mmc_card *card,
rpmb->dev.release = mmc_blk_rpmb_device_release;
device_initialize(&rpmb->dev);
dev_set_drvdata(&rpmb->dev, rpmb);
+ mmc_blk_get(md->disk);
rpmb->md = md;

cdev_init(&rpmb->chrdev, &mmc_rpmb_fileops);
@@ -3002,6 +3191,41 @@ static void mmc_blk_remove_debugfs(struct mmc_card *card,

#endif /* CONFIG_DEBUG_FS */

+static void mmc_blk_rpmb_add(struct mmc_card *card)
+{
+ struct mmc_blk_data *md = dev_get_drvdata(&card->dev);
+ struct mmc_rpmb_data *rpmb;
+ struct rpmb_dev *rdev;
+ unsigned int n;
+ u32 cid[4];
+ struct rpmb_descr descr = {
+ .type = RPMB_TYPE_EMMC,
+ .route_frames = mmc_route_rpmb_frames,
+ .reliable_wr_count = card->ext_csd.raw_rpmb_size_mult,
+ .capacity = card->ext_csd.rel_sectors,
+ .dev_id = (void *)cid,
+ .dev_id_len = sizeof(cid),
+ };
+
+ /*
+ * Provice CID as an octet array. The CID needs to be interpreted
+ * when used as input to derive the RPMB key since some fields
+ * will change due to firmware updates.
+ */
+ for (n = 0; n < 4; n++)
+ cid[n] = be32_to_cpu(card->raw_cid[n]);
+
+ list_for_each_entry(rpmb, &md->rpmbs, node) {
+ rdev = rpmb_dev_register(&rpmb->dev, &descr);
+ if (IS_ERR(rdev)) {
+ pr_warn("%s: could not register RPMB device\n",
+ dev_name(&rpmb->dev));
+ continue;
+ }
+ rpmb->rdev = rdev;
+ }
+}
+
static int mmc_blk_probe(struct mmc_card *card)
{
struct mmc_blk_data *md;
@@ -3047,6 +3271,8 @@ static int mmc_blk_probe(struct mmc_card *card)
pm_runtime_enable(&card->dev);
}

+ mmc_blk_rpmb_add(card);
+
return 0;

out:
--
2.34.1


2024-04-05 11:55:33

by Jens Wiklander

[permalink] [raw]
Subject: [PATCH v4 3/3] optee: probe RPMB device using RPMB subsystem

Adds support in the OP-TEE drivers (both SMC and FF-A ABIs) to probe and
use an RPMB device via the RPBM subsystem instead of passing the RPMB
frames via tee-supplicant in user space. A fallback mechanism is kept to
route RPMB frames via tee-supplicant if the RPMB subsystem isn't
available.

The OP-TEE RPC ABI is extended to support iterating over all RPMB
devices until one is found with the expected RPMB key already
programmed.

Signed-off-by: Jens Wiklander <[email protected]>
---
drivers/tee/optee/core.c | 30 ++++
drivers/tee/optee/device.c | 7 +
drivers/tee/optee/ffa_abi.c | 8 +
drivers/tee/optee/optee_private.h | 21 ++-
drivers/tee/optee/optee_rpc_cmd.h | 35 +++++
drivers/tee/optee/rpc.c | 233 ++++++++++++++++++++++++++++++
drivers/tee/optee/smc_abi.c | 7 +
7 files changed, 340 insertions(+), 1 deletion(-)

diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
index 3aed554bc8d8..082691c10a90 100644
--- a/drivers/tee/optee/core.c
+++ b/drivers/tee/optee/core.c
@@ -11,6 +11,7 @@
#include <linux/io.h>
#include <linux/mm.h>
#include <linux/module.h>
+#include <linux/rpmb.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/tee_drv.h>
@@ -80,6 +81,31 @@ void optee_pool_op_free_helper(struct tee_shm_pool *pool, struct tee_shm *shm,
shm->pages = NULL;
}

+void optee_bus_scan_rpmb(struct work_struct *work)
+{
+ struct optee *optee = container_of(work, struct optee,
+ rpmb_scan_bus_work);
+ int ret;
+
+ if (!optee->rpmb_scan_bus_done) {
+ ret = optee_enumerate_devices(PTA_CMD_GET_DEVICES_RPMB);
+ optee->rpmb_scan_bus_done = !ret;
+ if (ret && ret != -ENODEV)
+ pr_info("Scanning for RPMB device: ret %d\n", ret);
+ }
+}
+
+int optee_rpmb_intf_rdev(struct notifier_block *intf, unsigned long action,
+ void *data)
+{
+ struct optee *optee = container_of(intf, struct optee, rpmb_intf);
+
+ if (action == RPMB_NOTIFY_ADD_DEVICE)
+ schedule_work(&optee->rpmb_scan_bus_work);
+
+ return 0;
+}
+
static void optee_bus_scan(struct work_struct *work)
{
WARN_ON(optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP));
@@ -161,6 +187,8 @@ void optee_release_supp(struct tee_context *ctx)

void optee_remove_common(struct optee *optee)
{
+ rpmb_interface_unregister(&optee->rpmb_intf);
+ cancel_work_sync(&optee->rpmb_scan_bus_work);
/* Unregister OP-TEE specific client devices on TEE bus */
optee_unregister_devices();

@@ -177,6 +205,8 @@ void optee_remove_common(struct optee *optee)
tee_shm_pool_free(optee->pool);
optee_supp_uninit(&optee->supp);
mutex_destroy(&optee->call_queue.mutex);
+ rpmb_dev_put(optee->rpmb_dev);
+ mutex_destroy(&optee->rpmb_dev_mutex);
}

static int smc_abi_rc;
diff --git a/drivers/tee/optee/device.c b/drivers/tee/optee/device.c
index 4b1092127694..4274876857c8 100644
--- a/drivers/tee/optee/device.c
+++ b/drivers/tee/optee/device.c
@@ -43,6 +43,13 @@ static int get_devices(struct tee_context *ctx, u32 session,
ret = tee_client_invoke_func(ctx, &inv_arg, param);
if ((ret < 0) || ((inv_arg.ret != TEEC_SUCCESS) &&
(inv_arg.ret != TEEC_ERROR_SHORT_BUFFER))) {
+ /*
+ * TEE_ERROR_STORAGE_NOT_AVAILABLE is returned when getting
+ * the list of device TAs that depends on RPMB but a usable
+ * RPMB device isn't found.
+ */
+ if (inv_arg.ret == TEE_ERROR_STORAGE_NOT_AVAILABLE)
+ return -ENODEV;
pr_err("PTA_CMD_GET_DEVICES invoke function err: %x\n",
inv_arg.ret);
return -EINVAL;
diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c
index ecb5eb079408..a8dfdb30b4e8 100644
--- a/drivers/tee/optee/ffa_abi.c
+++ b/drivers/tee/optee/ffa_abi.c
@@ -7,6 +7,7 @@

#include <linux/arm_ffa.h>
#include <linux/errno.h>
+#include <linux/rpmb.h>
#include <linux/scatterlist.h>
#include <linux/sched.h>
#include <linux/slab.h>
@@ -934,6 +935,7 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
optee_cq_init(&optee->call_queue, 0);
optee_supp_init(&optee->supp);
optee_shm_arg_cache_init(optee, arg_cache_flags);
+ mutex_init(&optee->rpmb_dev_mutex);
ffa_dev_set_drvdata(ffa_dev, optee);
ctx = teedev_open(optee->teedev);
if (IS_ERR(ctx)) {
@@ -955,6 +957,9 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
if (rc)
goto err_unregister_devices;

+ INIT_WORK(&optee->rpmb_scan_bus_work, optee_bus_scan_rpmb);
+ optee->rpmb_intf.notifier_call = optee_rpmb_intf_rdev;
+ rpmb_interface_register(&optee->rpmb_intf);
pr_info("initialized driver\n");
return 0;

@@ -968,6 +973,9 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
teedev_close_context(ctx);
err_rhashtable_free:
rhashtable_free_and_destroy(&optee->ffa.global_ids, rh_free_fn, NULL);
+ rpmb_dev_put(optee->rpmb_dev);
+ mutex_destroy(&optee->rpmb_dev_mutex);
+ rpmb_interface_unregister(&optee->rpmb_intf);
optee_supp_uninit(&optee->supp);
mutex_destroy(&optee->call_queue.mutex);
mutex_destroy(&optee->ffa.mutex);
diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
index 7a5243c78b55..ae72f3dda1d2 100644
--- a/drivers/tee/optee/optee_private.h
+++ b/drivers/tee/optee/optee_private.h
@@ -8,6 +8,7 @@

#include <linux/arm-smccc.h>
#include <linux/rhashtable.h>
+#include <linux/rpmb.h>
#include <linux/semaphore.h>
#include <linux/tee_drv.h>
#include <linux/types.h>
@@ -20,11 +21,13 @@
/* Some Global Platform error codes used in this driver */
#define TEEC_SUCCESS 0x00000000
#define TEEC_ERROR_BAD_PARAMETERS 0xFFFF0006
+#define TEEC_ERROR_ITEM_NOT_FOUND 0xFFFF0008
#define TEEC_ERROR_NOT_SUPPORTED 0xFFFF000A
#define TEEC_ERROR_COMMUNICATION 0xFFFF000E
#define TEEC_ERROR_OUT_OF_MEMORY 0xFFFF000C
#define TEEC_ERROR_BUSY 0xFFFF000D
#define TEEC_ERROR_SHORT_BUFFER 0xFFFF0010
+#define TEE_ERROR_STORAGE_NOT_AVAILABLE 0xF0100003

#define TEEC_ORIGIN_COMMS 0x00000002

@@ -197,6 +200,12 @@ struct optee_ops {
* @notif: notification synchronization struct
* @supp: supplicant synchronization struct for RPC to supplicant
* @pool: shared memory pool
+ * @mutex: mutex protecting @rpmb_dev
+ * @rpmb_dev: current RPMB device or NULL
+ * @rpmb_scan_bus_done flag if device registation of RPMB dependent devices
+ * was already done
+ * @rpmb_scan_bus_work workq to for an RPMB device and to scan optee bus
+ * and register RPMB dependent optee drivers
* @rpc_param_count: If > 0 number of RPC parameters to make room for
* @scan_bus_done flag if device registation was already done.
* @scan_bus_work workq to scan optee bus and register optee drivers
@@ -215,9 +224,15 @@ struct optee {
struct optee_notif notif;
struct optee_supp supp;
struct tee_shm_pool *pool;
+ /* Protects rpmb_dev pointer */
+ struct mutex rpmb_dev_mutex;
+ struct rpmb_dev *rpmb_dev;
+ struct notifier_block rpmb_intf;
unsigned int rpc_param_count;
- bool scan_bus_done;
+ bool scan_bus_done;
+ bool rpmb_scan_bus_done;
struct work_struct scan_bus_work;
+ struct work_struct rpmb_scan_bus_work;
};

struct optee_session {
@@ -280,8 +295,12 @@ int optee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session);

#define PTA_CMD_GET_DEVICES 0x0
#define PTA_CMD_GET_DEVICES_SUPP 0x1
+#define PTA_CMD_GET_DEVICES_RPMB 0x2
int optee_enumerate_devices(u32 func);
void optee_unregister_devices(void);
+void optee_bus_scan_rpmb(struct work_struct *work);
+int optee_rpmb_intf_rdev(struct notifier_block *intf, unsigned long action,
+ void *data);

int optee_pool_op_alloc_helper(struct tee_shm_pool *pool, struct tee_shm *shm,
size_t size, size_t align,
diff --git a/drivers/tee/optee/optee_rpc_cmd.h b/drivers/tee/optee/optee_rpc_cmd.h
index f3f06e0994a7..f351a8ac69fc 100644
--- a/drivers/tee/optee/optee_rpc_cmd.h
+++ b/drivers/tee/optee/optee_rpc_cmd.h
@@ -16,6 +16,14 @@
* and sends responses.
*/

+/*
+ * Replay Protected Memory Block access
+ *
+ * [in] memref[0] Frames to device
+ * [out] memref[1] Frames from device
+ */
+#define OPTEE_RPC_CMD_RPMB 1
+
/*
* Get time
*
@@ -103,4 +111,31 @@
/* I2C master control flags */
#define OPTEE_RPC_I2C_FLAGS_TEN_BIT BIT(0)

+/*
+ * Reset RPMB probing
+ *
+ * Releases an eventually already used RPMB devices and starts over searching
+ * for RPMB devices. Returns the kind of shared memory to use in subsequent
+ * OPTEE_RPC_CMD_RPMB_PROBE_NEXT and OPTEE_RPC_CMD_RPMB calls.
+ *
+ * [out] value[0].a OPTEE_RPC_SHM_TYPE_*, the parameter for
+ * OPTEE_RPC_CMD_SHM_ALLOC
+ */
+#define OPTEE_RPC_CMD_RPMB_PROBE_RESET 22
+
+/*
+ * Probe next RPMB device
+ *
+ * [out] value[0].a Type of RPMB device, OPTEE_RPC_RPMB_*
+ * [out] value[0].b EXT CSD-slice 168 "RPMB Size"
+ * [out] value[0].c EXT CSD-slice 222 "Reliable Write Sector Count"
+ * [out] memref[1] Buffer with the raw CID
+ */
+#define OPTEE_RPC_CMD_RPMB_PROBE_NEXT 23
+
+/* Type of RPMB device */
+#define OPTEE_RPC_RPMB_EMMC 0
+#define OPTEE_RPC_RPMB_UFS 1
+#define OPTEE_RPC_RPMB_NVME 2
+
#endif /*__OPTEE_RPC_CMD_H*/
diff --git a/drivers/tee/optee/rpc.c b/drivers/tee/optee/rpc.c
index e69bc6380683..e211c1c94984 100644
--- a/drivers/tee/optee/rpc.c
+++ b/drivers/tee/optee/rpc.c
@@ -7,6 +7,7 @@

#include <linux/delay.h>
#include <linux/i2c.h>
+#include <linux/rpmb.h>
#include <linux/slab.h>
#include <linux/tee_drv.h>
#include "optee_private.h"
@@ -255,6 +256,229 @@ void optee_rpc_cmd_free_suppl(struct tee_context *ctx, struct tee_shm *shm)
optee_supp_thrd_req(ctx, OPTEE_RPC_CMD_SHM_FREE, 1, &param);
}

+static void handle_rpc_func_rpmb_probe_reset(struct tee_context *ctx,
+ struct optee *optee,
+ struct optee_msg_arg *arg)
+{
+ struct tee_param params[1];
+
+ if (!IS_ENABLED(CONFIG_RPMB)) {
+ handle_rpc_supp_cmd(ctx, optee, arg);
+ return;
+ }
+
+ if (arg->num_params != ARRAY_SIZE(params) ||
+ optee->ops->from_msg_param(optee, params, arg->num_params,
+ arg->params) ||
+ params[0].attr != TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT) {
+ arg->ret = TEEC_ERROR_BAD_PARAMETERS;
+ return;
+ }
+
+ params[0].u.value.a = OPTEE_RPC_SHM_TYPE_KERNEL;
+ params[0].u.value.b = 0;
+ params[0].u.value.c = 0;
+ if (optee->ops->to_msg_param(optee, arg->params,
+ arg->num_params, params)) {
+ arg->ret = TEEC_ERROR_BAD_PARAMETERS;
+ return;
+ }
+
+ mutex_lock(&optee->rpmb_dev_mutex);
+ rpmb_dev_put(optee->rpmb_dev);
+ optee->rpmb_dev = NULL;
+ mutex_unlock(&optee->rpmb_dev_mutex);
+
+ arg->ret = TEEC_SUCCESS;
+}
+
+static int rpmb_type_to_rpc_type(enum rpmb_type rtype)
+{
+ switch (rtype) {
+ case RPMB_TYPE_EMMC:
+ return OPTEE_RPC_RPMB_EMMC;
+ case RPMB_TYPE_UFS:
+ return OPTEE_RPC_RPMB_UFS;
+ case RPMB_TYPE_NVME:
+ return OPTEE_RPC_RPMB_NVME;
+ default:
+ return -1;
+ }
+}
+
+static int rpc_rpmb_match(struct rpmb_dev *rdev, const void *data)
+{
+ return rpmb_type_to_rpc_type(rdev->descr.type) >= 0;
+}
+
+static void handle_rpc_func_rpmb_probe_next(struct tee_context *ctx,
+ struct optee *optee,
+ struct optee_msg_arg *arg)
+{
+ struct rpmb_dev *rdev;
+ struct tee_param params[2];
+ void *buf;
+
+ if (!IS_REACHABLE(CONFIG_RPMB)) {
+ handle_rpc_supp_cmd(ctx, optee, arg);
+ return;
+ }
+
+ if (arg->num_params != ARRAY_SIZE(params) ||
+ optee->ops->from_msg_param(optee, params, arg->num_params,
+ arg->params) ||
+ params[0].attr != TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT ||
+ params[1].attr != TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT) {
+ arg->ret = TEEC_ERROR_BAD_PARAMETERS;
+ return;
+ }
+ buf = tee_shm_get_va(params[1].u.memref.shm,
+ params[1].u.memref.shm_offs);
+ if (!buf) {
+ arg->ret = TEEC_ERROR_BAD_PARAMETERS;
+ return;
+ }
+
+ mutex_lock(&optee->rpmb_dev_mutex);
+ rdev = rpmb_dev_find_device(NULL, optee->rpmb_dev, rpc_rpmb_match);
+ rpmb_dev_put(optee->rpmb_dev);
+ optee->rpmb_dev = rdev;
+ mutex_unlock(&optee->rpmb_dev_mutex);
+
+ if (!rdev) {
+ arg->ret = TEEC_ERROR_ITEM_NOT_FOUND;
+ return;
+ }
+
+ if (params[1].u.memref.size < rdev->descr.dev_id_len) {
+ arg->ret = TEEC_ERROR_SHORT_BUFFER;
+ return;
+ }
+ memcpy(buf, rdev->descr.dev_id, rdev->descr.dev_id_len);
+ params[1].u.memref.size = rdev->descr.dev_id_len;
+ params[0].u.value.a = rpmb_type_to_rpc_type(rdev->descr.type);
+ params[0].u.value.b = rdev->descr.capacity;
+ params[0].u.value.c = rdev->descr.reliable_wr_count;
+ if (optee->ops->to_msg_param(optee, arg->params,
+ arg->num_params, params)) {
+ arg->ret = TEEC_ERROR_BAD_PARAMETERS;
+ return;
+ }
+
+ arg->ret = TEEC_SUCCESS;
+}
+
+/* Request */
+struct rpmb_req {
+ u16 cmd;
+#define RPMB_CMD_DATA_REQ 0x00
+#define RPMB_CMD_GET_DEV_INFO 0x01
+ u16 dev_id;
+ u16 block_count;
+ /* Optional data frames (rpmb_data_frame) follow */
+};
+
+#define RPMB_REQ_DATA(req) ((void *)((struct rpmb_req *)(req) + 1))
+
+#define RPMB_CID_SZ 16
+
+/* Response to device info request */
+struct rpmb_dev_info {
+ u8 cid[RPMB_CID_SZ];
+ u8 rpmb_size_mult; /* EXT CSD-slice 168: RPMB Size */
+ u8 rel_wr_sec_c; /* EXT CSD-slice 222: Reliable Write Sector */
+ /* Count */
+ u8 ret_code;
+#define RPMB_CMD_GET_DEV_INFO_RET_OK 0x00
+#define RPMB_CMD_GET_DEV_INFO_RET_ERROR 0x01
+};
+
+static int get_dev_info(struct rpmb_dev *rdev, void *rsp, size_t rsp_size)
+{
+ struct rpmb_dev_info *dev_info;
+
+ if (rsp_size != sizeof(*dev_info))
+ return TEEC_ERROR_BAD_PARAMETERS;
+
+ dev_info = rsp;
+ memcpy(dev_info->cid, rdev->descr.dev_id, sizeof(dev_info->cid));
+ dev_info->rpmb_size_mult = rdev->descr.capacity;
+ dev_info->rel_wr_sec_c = rdev->descr.reliable_wr_count;
+ dev_info->ret_code = RPMB_CMD_GET_DEV_INFO_RET_OK;
+
+ return TEEC_SUCCESS;
+}
+
+/*
+ * req is one struct rpmb_req followed by one or more struct rpmb_data_frame
+ * rsp is either one struct rpmb_dev_info or one or more struct rpmb_data_frame
+ */
+static u32 rpmb_process_request(struct optee *optee, struct rpmb_dev *rdev,
+ void *req, size_t req_size,
+ void *rsp, size_t rsp_size)
+{
+ struct rpmb_req *sreq = req;
+ int rc;
+
+ if (req_size < sizeof(*sreq))
+ return TEEC_ERROR_BAD_PARAMETERS;
+
+ switch (sreq->cmd) {
+ case RPMB_CMD_DATA_REQ:
+ rc = rpmb_route_frames(rdev, RPMB_REQ_DATA(req),
+ req_size - sizeof(struct rpmb_req),
+ rsp, rsp_size);
+ if (rc)
+ return TEEC_ERROR_BAD_PARAMETERS;
+ return TEEC_SUCCESS;
+ case RPMB_CMD_GET_DEV_INFO:
+ return get_dev_info(rdev, rsp, rsp_size);
+ default:
+ return TEEC_ERROR_BAD_PARAMETERS;
+ }
+}
+
+static void handle_rpc_func_rpmb(struct tee_context *ctx, struct optee *optee,
+ struct optee_msg_arg *arg)
+{
+ struct tee_param params[2];
+ struct rpmb_dev *rdev;
+ void *p0, *p1;
+
+ mutex_lock(&optee->rpmb_dev_mutex);
+ rdev = rpmb_dev_get(optee->rpmb_dev);
+ mutex_unlock(&optee->rpmb_dev_mutex);
+ if (!rdev) {
+ handle_rpc_supp_cmd(ctx, optee, arg);
+ return;
+ }
+
+ if (arg->num_params != ARRAY_SIZE(params) ||
+ optee->ops->from_msg_param(optee, params, arg->num_params,
+ arg->params) ||
+ params[0].attr != TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT ||
+ params[1].attr != TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT) {
+ arg->ret = TEEC_ERROR_BAD_PARAMETERS;
+ goto out;
+ }
+
+ p0 = tee_shm_get_va(params[0].u.memref.shm,
+ params[0].u.memref.shm_offs);
+ p1 = tee_shm_get_va(params[1].u.memref.shm,
+ params[1].u.memref.shm_offs);
+ arg->ret = rpmb_process_request(optee, rdev, p0,
+ params[0].u.memref.size,
+ p1, params[1].u.memref.size);
+ if (arg->ret)
+ goto out;
+
+ if (optee->ops->to_msg_param(optee, arg->params,
+ arg->num_params, params))
+ arg->ret = TEEC_ERROR_BAD_PARAMETERS;
+out:
+ rpmb_dev_put(rdev);
+}
+
void optee_rpc_cmd(struct tee_context *ctx, struct optee *optee,
struct optee_msg_arg *arg)
{
@@ -271,6 +495,15 @@ void optee_rpc_cmd(struct tee_context *ctx, struct optee *optee,
case OPTEE_RPC_CMD_I2C_TRANSFER:
handle_rpc_func_cmd_i2c_transfer(ctx, arg);
break;
+ case OPTEE_RPC_CMD_RPMB_PROBE_RESET:
+ handle_rpc_func_rpmb_probe_reset(ctx, optee, arg);
+ break;
+ case OPTEE_RPC_CMD_RPMB_PROBE_NEXT:
+ handle_rpc_func_rpmb_probe_next(ctx, optee, arg);
+ break;
+ case OPTEE_RPC_CMD_RPMB:
+ handle_rpc_func_rpmb(ctx, optee, arg);
+ break;
default:
handle_rpc_supp_cmd(ctx, optee, arg);
}
diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c
index a37f87087e5c..c23bcf35c8cb 100644
--- a/drivers/tee/optee/smc_abi.c
+++ b/drivers/tee/optee/smc_abi.c
@@ -20,6 +20,7 @@
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
+#include <linux/rpmb.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/string.h>
@@ -1715,6 +1716,7 @@ static int optee_probe(struct platform_device *pdev)
optee->smc.memremaped_shm = memremaped_shm;
optee->pool = pool;
optee_shm_arg_cache_init(optee, arg_cache_flags);
+ mutex_init(&optee->rpmb_dev_mutex);

platform_set_drvdata(pdev, optee);
ctx = teedev_open(optee->teedev);
@@ -1769,6 +1771,9 @@ static int optee_probe(struct platform_device *pdev)
if (rc)
goto err_disable_shm_cache;

+ INIT_WORK(&optee->rpmb_scan_bus_work, optee_bus_scan_rpmb);
+ optee->rpmb_intf.notifier_call = optee_rpmb_intf_rdev;
+ rpmb_interface_register(&optee->rpmb_intf);
pr_info("initialized driver\n");
return 0;

@@ -1782,6 +1787,8 @@ static int optee_probe(struct platform_device *pdev)
err_close_ctx:
teedev_close_context(ctx);
err_supp_uninit:
+ rpmb_dev_put(optee->rpmb_dev);
+ mutex_destroy(&optee->rpmb_dev_mutex);
optee_shm_arg_cache_uninit(optee);
optee_supp_uninit(&optee->supp);
mutex_destroy(&optee->call_queue.mutex);
--
2.34.1


2024-04-06 10:27:35

by Avri Altman

[permalink] [raw]
Subject: RE: [PATCH v4 1/3] rpmb: add Replay Protected Memory Block (RPMB) subsystem

> A number of storage technologies support a specialised hardware
> partition designed to be resistant to replay attacks. The underlying
> HW protocols differ but the operations are common. The RPMB partition
> cannot be accessed via standard block layer, but by a set of specific
> RPMB commands: WRITE, READ, GET_WRITE_COUNTER, and PROGRAM_KEY.
What about the other rpmb operations?
There are 7 operations in eMMC.

............

> +/**
> + * rpmb_dev_find_device() - return first matching rpmb device
> + * @data: data for the match function
> + * @match: the matching function
> + *
> + * Iterate over registered RPMB devices, and call @match() for each passing
> + * it the RPMB device and @data.
> + *
> + * The return value of @match() is checked for each call. If it returns
> + * anything other 0, break and return the found RPMB device.
> + *
> + * It's the callers responsibility to call rpmb_dev_put() on the returned
> + * device, when it's done with it.
> + *
> + * Returns: a matching rpmb device or NULL on failure
> + */
> +struct rpmb_dev *rpmb_dev_find_device(const void *data,
> + const struct rpmb_dev *start,
> + int (*match)(struct rpmb_dev *rdev,
> + const void *data))
> +{
> + struct rpmb_dev *rdev;
> + struct list_head *pos;
> +
> + mutex_lock(&rpmb_mutex);
> + if (start)
> + pos = start->list_node.next;
> + else
> + pos = rpmb_dev_list.next;
> +
> + while (pos != &rpmb_dev_list) {
Why not just list_for_each_entry instead?

> + rdev = container_of(pos, struct rpmb_dev, list_node);
> + if (match(rdev, data)) {
> + rpmb_dev_get(rdev);
> + goto out;
> + }
> + pos = pos->next;
> + }
> + rdev = NULL;
> +
> +out:
> + mutex_unlock(&rpmb_mutex);
> +
> + return rdev;
> +}

.....................

> +/**
> + * rpmb_dev_register - register RPMB partition with the RPMB subsystem
> + * @dev: storage device of the rpmb device
> + * @ops: device specific operations
> + *
> + * While registering the RPMB partition extract needed device information
> + * while needed resources are available.
> + *
> + * Returns: a pointer to a 'struct rpmb_dev' or an ERR_PTR on failure
> + */
> +struct rpmb_dev *rpmb_dev_register(struct device *dev,
> + struct rpmb_descr *descr)
> +{
> + struct rpmb_dev *rdev;
> +
> + if (!dev || !descr || !descr->route_frames || !descr->dev_id ||
> + !descr->dev_id_len)
> + return ERR_PTR(-EINVAL);
> +
> + rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
> + if (!rdev)
> + return ERR_PTR(-ENOMEM);
> + rdev->descr = *descr;
> + rdev->descr.dev_id = kmemdup(descr->dev_id, descr->dev_id_len,
> + GFP_KERNEL);
In addition to the dev_id, wouldn't it make sense to have your own IDA as well?

> + if (!rdev->descr.dev_id) {
> + kfree(rdev);
> + return ERR_PTR(-ENOMEM);
> + }
> +
> + rdev->parent_dev = dev;
> +
> + dev_dbg(rdev->parent_dev, "registered device\n");
> +
> + mutex_lock(&rpmb_mutex);
> + list_add_tail(&rdev->list_node, &rpmb_dev_list);
> + blocking_notifier_call_chain(&rpmb_interface,
> RPMB_NOTIFY_ADD_DEVICE,
> + rdev);
> + mutex_unlock(&rpmb_mutex);
> +
> + return rdev;
> +}
> +EXPORT_SYMBOL_GPL(rpmb_dev_register);

............

> new file mode 100644
> index 000000000000..251d6b7e6d15
> --- /dev/null
> +++ b/include/linux/rpmb.h
> @@ -0,0 +1,136 @@
> +/* SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 */
> +/*
> + * Copyright (C) 2015-2019 Intel Corp. All rights reserved
> + * Copyright (C) 2021-2022 Linaro Ltd
> + */
> +#ifndef __RPMB_H__
> +#define __RPMB_H__
> +
> +#include <linux/types.h>
> +#include <linux/device.h>
> +#include <linux/notifier.h>
> +
> +/**
> + * enum rpmb_type - type of underlying storage technology
> + *
> + * @RPMB_TYPE_EMMC : emmc (JESD84-B50.1)
> + * @RPMB_TYPE_UFS : UFS (JESD220)
> + * @RPMB_TYPE_NVME : NVM Express
> + */
> +enum rpmb_type {
> + RPMB_TYPE_EMMC,
> + RPMB_TYPE_UFS,
> + RPMB_TYPE_NVME,
> +};
> +
> +/**
> + * struct rpmb_descr - RPMB descriptor provided by the underlying block
> device
The use of the term "rpmb descriptor" may be slightly misleading.
This is because in UFS there are various descriptors that identifies various characteristics,
e.g. device descriptor, geometry descriptor, unit descriptor etc.,
and recently UFS4.0 introduced a new descriptor - RPMB descriptor....

Thanks,
Avri

2024-04-06 11:22:34

by Avri Altman

[permalink] [raw]
Subject: RE: [PATCH v4 2/3] mmc: block: register RPMB partition with the RPMB subsystem


> +
> +#define RPMB_PROGRAM_KEY 0x1 /* Program RPMB Authentication
You expect the key to be already programmed - so you don't really need this operation?

> Key */
> +#define RPMB_GET_WRITE_COUNTER 0x2 /* Read RPMB write counter */
> +#define RPMB_WRITE_DATA 0x3 /* Write data to RPMB partition */
> +#define RPMB_READ_DATA 0x4 /* Read data from RPMB partition */
> +#define RPMB_RESULT_READ 0x5 /* Read result request (Internal) */
> +
> static DEFINE_MUTEX(block_mutex);
>
> /*
> @@ -163,6 +205,7 @@ struct mmc_rpmb_data {
> int id;
> unsigned int part_index;
> struct mmc_blk_data *md;
> + struct rpmb_dev *rdev;
> struct list_head node;
> };
>
> @@ -2672,7 +2715,6 @@ static int mmc_rpmb_chrdev_open(struct inode
> *inode, struct file *filp)
>
> get_device(&rpmb->dev);
> filp->private_data = rpmb;
> - mmc_blk_get(rpmb->md->disk);
Maybe add a comment that this has moved to mmc_blk_alloc_rpmb_part?
For those who will look for it.

>
> return nonseekable_open(inode, filp); } @@ -2682,7 +2724,6 @@ static
> int mmc_rpmb_chrdev_release(struct inode *inode, struct file *filp)
> struct mmc_rpmb_data *rpmb = container_of(inode->i_cdev,
> struct mmc_rpmb_data, chrdev);
>
> - mmc_blk_put(rpmb->md);
Ditto.

> put_device(&rpmb->dev);
>
> return 0;
> @@ -2703,10 +2744,157 @@ static void mmc_blk_rpmb_device_release(struct
> device *dev) {
> struct mmc_rpmb_data *rpmb = dev_get_drvdata(dev);
>
> + rpmb_dev_unregister(rpmb->rdev);
> + mmc_blk_put(rpmb->md);
> ida_simple_remove(&mmc_rpmb_ida, rpmb->id);
> kfree(rpmb);
> }
>
> +static void free_idata(struct mmc_blk_ioc_data **idata, unsigned int
> +cmd_count) {
> + unsigned int n;
> +
> + for (n = 0; n < cmd_count; n++)
> + kfree(idata[n]);
> + kfree(idata);
> +}
> +
> +static struct mmc_blk_ioc_data **alloc_idata(struct mmc_rpmb_data *rpmb,
> + unsigned int cmd_count) {
> + struct mmc_blk_ioc_data **idata;
> + unsigned int n;
> +
> + idata = kcalloc(cmd_count, sizeof(*idata), GFP_KERNEL);
> + if (!idata)
> + return NULL;
> +
> + for (n = 0; n < cmd_count; n++) {
> + idata[n] = kcalloc(1, sizeof(**idata), GFP_KERNEL);
> + if (!idata[n]) {
> + free_idata(idata, n);
> + return NULL;
> + }
> + idata[n]->rpmb = rpmb;
> + }
> +
> + return idata;
> +}
> +
> +static void set_idata(struct mmc_blk_ioc_data *idata, u32 opcode,
> + int write_flag, u8 *buf, unsigned int buf_bytes) {
> + idata->ic.opcode = opcode;
> + idata->ic.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
> + idata->ic.write_flag = write_flag;
> + idata->ic.blksz = sizeof(struct rpmb_frame);
blksz = 512, so maybe add a compile-time check on sizeof(struct rpmb_frame)?

> + idata->ic.blocks = buf_bytes / idata->ic.blksz;
> + idata->buf = buf;
> + idata->buf_bytes = buf_bytes;
> +}
> +
> +static int mmc_route_rpmb_frames(struct device *dev, u8 *req,
> + unsigned int req_len, u8 *resp,
> + unsigned int resp_len) {
> + struct rpmb_frame *frm = (struct rpmb_frame *)req;
> + struct mmc_rpmb_data *rpmb = dev_get_drvdata(dev);
> + struct mmc_blk_data *md = rpmb->md;
> + struct mmc_blk_ioc_data **idata;
> + unsigned int cmd_count;
> + struct request *rq;
> + u16 req_type;
> + bool write;
> + int ret;
> +
> + if (IS_ERR(md->queue.card))
> + return PTR_ERR(md->queue.card);
> +
> + if (req_len < sizeof(*frm))
> + return -EINVAL;
> +
> + req_type = be16_to_cpu(frm->req_resp);
> + switch (req_type) {
> + case RPMB_PROGRAM_KEY:
> + if (req_len != sizeof(struct rpmb_frame) ||
> + resp_len != sizeof(struct rpmb_frame))
> + return -EINVAL;
> + write = true;
> + break;
> + case RPMB_GET_WRITE_COUNTER:
> + if (req_len != sizeof(struct rpmb_frame) ||
> + resp_len != sizeof(struct rpmb_frame))
> + return -EINVAL;
> + write = false;
> + break;
> + case RPMB_WRITE_DATA:
> + if (req_len % sizeof(struct rpmb_frame) ||
> + resp_len != sizeof(struct rpmb_frame))
> + return -EINVAL;
> + write = true;
> + break;
> + case RPMB_READ_DATA:
> + if (req_len != sizeof(struct rpmb_frame) ||
> + resp_len % sizeof(struct rpmb_frame))
> + return -EINVAL;
> + write = false;
> + break;
> + default:
> + return -EINVAL;
> + }
Looks like the above input validation section can be reduced to is RPMB_WRITE_DATA and default?

> +
> + if (write)
> + cmd_count = 3;
> + else
> + cmd_count = 2;
> +
> + idata = alloc_idata(rpmb, cmd_count);
> + if (!idata)
> + return -ENOMEM;
> +
> + if (write) {
> + struct rpmb_frame *frm = (struct rpmb_frame *)resp;
> +
> + /* Send write request frame(s) */
> + set_idata(idata[0], MMC_WRITE_MULTIPLE_BLOCK,
> + 1 | MMC_CMD23_ARG_REL_WR, req, req_len);
> +
> + /* Send result request frame */
> + memset(frm, 0, sizeof(*frm));
> + frm->req_resp = cpu_to_be16(RPMB_RESULT_READ);
> + set_idata(idata[1], MMC_WRITE_MULTIPLE_BLOCK, 1, resp,
> + resp_len);
> +
> + /* Read response frame */
> + set_idata(idata[2], MMC_READ_MULTIPLE_BLOCK, 0, resp,
> resp_len);
It is confusing to me that your response is holding 2 frame types:
The status frame and the response frame.


> + } else {
> + /* Send write request frame(s) */
> + set_idata(idata[0], MMC_WRITE_MULTIPLE_BLOCK, 1, req,
> + req_len);
> +
> + /* Read response frame */
> + set_idata(idata[1], MMC_READ_MULTIPLE_BLOCK, 0, resp,
> resp_len);
> + }
> +
> + rq = blk_mq_alloc_request(md->queue.queue, REQ_OP_DRV_OUT, 0);
> + if (IS_ERR(rq)) {
> + ret = PTR_ERR(rq);
> + goto out;
> + }
> +
> + req_to_mmc_queue_req(rq)->drv_op = MMC_DRV_OP_IOCTL_RPMB;
> + req_to_mmc_queue_req(rq)->drv_op_result = -EIO;
> + req_to_mmc_queue_req(rq)->drv_op_data = idata;
> + req_to_mmc_queue_req(rq)->ioc_count = cmd_count;
Maybe have an additional struct mmc_queue_req *mq_rq = req_to_mmc_queue_req(rq);

> + blk_execute_rq(rq, false);
> + ret = req_to_mmc_queue_req(rq)->drv_op_result;
> +
> + blk_mq_free_request(rq);
> +
> +out:
> + free_idata(idata, cmd_count);
> + return ret;
> +}
> +
> static int mmc_blk_alloc_rpmb_part(struct mmc_card *card,
> struct mmc_blk_data *md,
> unsigned int part_index, @@ -2741,6 +2929,7 @@ static
> int mmc_blk_alloc_rpmb_part(struct mmc_card *card,
> rpmb->dev.release = mmc_blk_rpmb_device_release;
> device_initialize(&rpmb->dev);
> dev_set_drvdata(&rpmb->dev, rpmb);
> + mmc_blk_get(md->disk);
> rpmb->md = md;
>
> cdev_init(&rpmb->chrdev, &mmc_rpmb_fileops); @@ -3002,6 +3191,41
> @@ static void mmc_blk_remove_debugfs(struct mmc_card *card,
>
> #endif /* CONFIG_DEBUG_FS */
>
> +static void mmc_blk_rpmb_add(struct mmc_card *card) {
> + struct mmc_blk_data *md = dev_get_drvdata(&card->dev);
> + struct mmc_rpmb_data *rpmb;
> + struct rpmb_dev *rdev;
> + unsigned int n;
> + u32 cid[4];
> + struct rpmb_descr descr = {
> + .type = RPMB_TYPE_EMMC,
> + .route_frames = mmc_route_rpmb_frames,
> + .reliable_wr_count = card->ext_csd.raw_rpmb_size_mult,
> + .capacity = card->ext_csd.rel_sectors,
The capacity is RPMB_SIZE_MULT and also limited to 16MB?
And you also need the region size you are writing to.
If I get your intention regarding reliable_wr_count, AFAIK, rpmb can be written either as a single, double, or 32 frames.
And this should be induced from card->ext_csd.rel_param, and not card->ext_csd.rel_sectors.

> + .dev_id = (void *)cid,
> + .dev_id_len = sizeof(cid),
> + };
> +
> + /*
> + * Provice CID as an octet array. The CID needs to be interpreted
> + * when used as input to derive the RPMB key since some fields
> + * will change due to firmware updates.
> + */
Not sure how the CID register is related to RPMB?
Is this something internal to TEE?

> + for (n = 0; n < 4; n++)
> + cid[n] = be32_to_cpu(card->raw_cid[n]);
> +
> + list_for_each_entry(rpmb, &md->rpmbs, node) {
> + rdev = rpmb_dev_register(&rpmb->dev, &descr);
> + if (IS_ERR(rdev)) {
> + pr_warn("%s: could not register RPMB device\n",
> + dev_name(&rpmb->dev));
> + continue;
> + }
> + rpmb->rdev = rdev;
> + }
> +}
> +

Thanks,
Avri

2024-04-06 15:31:43

by Winkler, Tomas

[permalink] [raw]
Subject: RE: [PATCH v4 2/3] mmc: block: register RPMB partition with the RPMB subsystem

>
>
> > +
> > +#define RPMB_PROGRAM_KEY 0x1 /* Program RPMB Authentication
> You expect the key to be already programmed - so you don't really need this
> operation?
Depends in what manufacturing flow you program the device, second I believe in the original series was also a simulation device,
This is important as the real device can be programmed only once.
>
> > Key */
> > +#define RPMB_GET_WRITE_COUNTER 0x2 /* Read RPMB write counter
> */
> > +#define RPMB_WRITE_DATA 0x3 /* Write data to RPMB partition */
> > +#define RPMB_READ_DATA 0x4 /* Read data from RPMB partition
> */
> > +#define RPMB_RESULT_READ 0x5 /* Read result request (Internal)
> */
> > +
> > static DEFINE_MUTEX(block_mutex);
> >
> > /*
> > @@ -163,6 +205,7 @@ struct mmc_rpmb_data {
> > int id;
> > unsigned int part_index;
> > struct mmc_blk_data *md;
> > + struct rpmb_dev *rdev;
> > struct list_head node;
> > };
> >
> > @@ -2672,7 +2715,6 @@ static int mmc_rpmb_chrdev_open(struct inode
> > *inode, struct file *filp)
> >
> > get_device(&rpmb->dev);
> > filp->private_data = rpmb;
> > - mmc_blk_get(rpmb->md->disk);
> Maybe add a comment that this has moved to mmc_blk_alloc_rpmb_part?
> For those who will look for it.
>
> >
> > return nonseekable_open(inode, filp); } @@ -2682,7 +2724,6 @@
> > static int mmc_rpmb_chrdev_release(struct inode *inode, struct file *filp)
> > struct mmc_rpmb_data *rpmb = container_of(inode->i_cdev,
> > struct
> > mmc_rpmb_data, chrdev);
> >
> > - mmc_blk_put(rpmb->md);
> Ditto.
>
> > put_device(&rpmb->dev);
> >
> > return 0;
> > @@ -2703,10 +2744,157 @@ static void
> > mmc_blk_rpmb_device_release(struct
> > device *dev) {
> > struct mmc_rpmb_data *rpmb = dev_get_drvdata(dev);
> >
> > + rpmb_dev_unregister(rpmb->rdev);
> > + mmc_blk_put(rpmb->md);
> > ida_simple_remove(&mmc_rpmb_ida, rpmb->id);
> > kfree(rpmb);
> > }
> >
> > +static void free_idata(struct mmc_blk_ioc_data **idata, unsigned int
> > +cmd_count) {
> > + unsigned int n;
> > +
> > + for (n = 0; n < cmd_count; n++)
> > + kfree(idata[n]);
> > + kfree(idata);
> > +}
> > +
> > +static struct mmc_blk_ioc_data **alloc_idata(struct mmc_rpmb_data
> *rpmb,
> > + unsigned int cmd_count) {
> > + struct mmc_blk_ioc_data **idata;
> > + unsigned int n;
> > +
> > + idata = kcalloc(cmd_count, sizeof(*idata), GFP_KERNEL);
> > + if (!idata)
> > + return NULL;
> > +
> > + for (n = 0; n < cmd_count; n++) {
> > + idata[n] = kcalloc(1, sizeof(**idata), GFP_KERNEL);
> > + if (!idata[n]) {
> > + free_idata(idata, n);
> > + return NULL;
> > + }
> > + idata[n]->rpmb = rpmb;
> > + }
> > +
> > + return idata;
> > +}
> > +
> > +static void set_idata(struct mmc_blk_ioc_data *idata, u32 opcode,
> > + int write_flag, u8 *buf, unsigned int buf_bytes) {
> > + idata->ic.opcode = opcode;
> > + idata->ic.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
> > + idata->ic.write_flag = write_flag;
> > + idata->ic.blksz = sizeof(struct rpmb_frame);
> blksz = 512, so maybe add a compile-time check on sizeof(struct
> rpmb_frame)?
>
> > + idata->ic.blocks = buf_bytes / idata->ic.blksz;
> > + idata->buf = buf;
> > + idata->buf_bytes = buf_bytes;
> > +}
> > +
> > +static int mmc_route_rpmb_frames(struct device *dev, u8 *req,
> > + unsigned int req_len, u8 *resp,
> > + unsigned int resp_len) {
> > + struct rpmb_frame *frm = (struct rpmb_frame *)req;
> > + struct mmc_rpmb_data *rpmb = dev_get_drvdata(dev);
> > + struct mmc_blk_data *md = rpmb->md;
> > + struct mmc_blk_ioc_data **idata;
> > + unsigned int cmd_count;
> > + struct request *rq;
> > + u16 req_type;
> > + bool write;
> > + int ret;
> > +
> > + if (IS_ERR(md->queue.card))
> > + return PTR_ERR(md->queue.card);
> > +
> > + if (req_len < sizeof(*frm))
> > + return -EINVAL;
> > +
> > + req_type = be16_to_cpu(frm->req_resp);
> > + switch (req_type) {
> > + case RPMB_PROGRAM_KEY:
> > + if (req_len != sizeof(struct rpmb_frame) ||
> > + resp_len != sizeof(struct rpmb_frame))
> > + return -EINVAL;
> > + write = true;
> > + break;
> > + case RPMB_GET_WRITE_COUNTER:
> > + if (req_len != sizeof(struct rpmb_frame) ||
> > + resp_len != sizeof(struct rpmb_frame))
> > + return -EINVAL;
> > + write = false;
> > + break;
> > + case RPMB_WRITE_DATA:
> > + if (req_len % sizeof(struct rpmb_frame) ||
> > + resp_len != sizeof(struct rpmb_frame))
> > + return -EINVAL;
> > + write = true;
> > + break;
> > + case RPMB_READ_DATA:
> > + if (req_len != sizeof(struct rpmb_frame) ||
> > + resp_len % sizeof(struct rpmb_frame))
> > + return -EINVAL;
> > + write = false;
> > + break;
> > + default:
> > + return -EINVAL;
> > + }
> Looks like the above input validation section can be reduced to is
> RPMB_WRITE_DATA and default?
>
> > +
> > + if (write)
> > + cmd_count = 3;
> > + else
> > + cmd_count = 2;
> > +
> > + idata = alloc_idata(rpmb, cmd_count);
> > + if (!idata)
> > + return -ENOMEM;
> > +
> > + if (write) {
> > + struct rpmb_frame *frm = (struct rpmb_frame *)resp;
> > +
> > + /* Send write request frame(s) */
> > + set_idata(idata[0], MMC_WRITE_MULTIPLE_BLOCK,
> > + 1 | MMC_CMD23_ARG_REL_WR, req, req_len);
> > +
> > + /* Send result request frame */
> > + memset(frm, 0, sizeof(*frm));
> > + frm->req_resp = cpu_to_be16(RPMB_RESULT_READ);
> > + set_idata(idata[1], MMC_WRITE_MULTIPLE_BLOCK, 1, resp,
> > + resp_len);
> > +
> > + /* Read response frame */
> > + set_idata(idata[2], MMC_READ_MULTIPLE_BLOCK, 0, resp,
> > resp_len);
> It is confusing to me that your response is holding 2 frame types:
> The status frame and the response frame.
Refer to the spec.

>
>
> > + } else {
> > + /* Send write request frame(s) */
> > + set_idata(idata[0], MMC_WRITE_MULTIPLE_BLOCK, 1, req,
> > + req_len);
> > +
> > + /* Read response frame */
> > + set_idata(idata[1], MMC_READ_MULTIPLE_BLOCK, 0, resp,
> > resp_len);
> > + }
> > +
> > + rq = blk_mq_alloc_request(md->queue.queue, REQ_OP_DRV_OUT,
> 0);
> > + if (IS_ERR(rq)) {
> > + ret = PTR_ERR(rq);
> > + goto out;
> > + }
> > +
> > + req_to_mmc_queue_req(rq)->drv_op =
> MMC_DRV_OP_IOCTL_RPMB;
> > + req_to_mmc_queue_req(rq)->drv_op_result = -EIO;
> > + req_to_mmc_queue_req(rq)->drv_op_data = idata;
> > + req_to_mmc_queue_req(rq)->ioc_count = cmd_count;
> Maybe have an additional struct mmc_queue_req *mq_rq =
> req_to_mmc_queue_req(rq);
>
> > + blk_execute_rq(rq, false);
> > + ret = req_to_mmc_queue_req(rq)->drv_op_result;
> > +
> > + blk_mq_free_request(rq);
> > +
> > +out:
> > + free_idata(idata, cmd_count);
> > + return ret;
> > +}
> > +
> > static int mmc_blk_alloc_rpmb_part(struct mmc_card *card,
> > struct mmc_blk_data *md,
> > unsigned int part_index, @@ -2741,6
> > +2929,7 @@ static int mmc_blk_alloc_rpmb_part(struct mmc_card *card,
> > rpmb->dev.release = mmc_blk_rpmb_device_release;
> > device_initialize(&rpmb->dev);
> > dev_set_drvdata(&rpmb->dev, rpmb);
> > + mmc_blk_get(md->disk);
> > rpmb->md = md;
> >
> > cdev_init(&rpmb->chrdev, &mmc_rpmb_fileops); @@ -3002,6
> > +3191,41 @@ static void mmc_blk_remove_debugfs(struct mmc_card
> *card,
> >
> > #endif /* CONFIG_DEBUG_FS */
> >
> > +static void mmc_blk_rpmb_add(struct mmc_card *card) {
> > + struct mmc_blk_data *md = dev_get_drvdata(&card->dev);
> > + struct mmc_rpmb_data *rpmb;
> > + struct rpmb_dev *rdev;
> > + unsigned int n;
> > + u32 cid[4];
> > + struct rpmb_descr descr = {
> > + .type = RPMB_TYPE_EMMC,
> > + .route_frames = mmc_route_rpmb_frames,
> > + .reliable_wr_count = card->ext_csd.raw_rpmb_size_mult,
> > + .capacity = card->ext_csd.rel_sectors,
> The capacity is RPMB_SIZE_MULT and also limited to 16MB?
> And you also need the region size you are writing to.
> If I get your intention regarding reliable_wr_count, AFAIK, rpmb can be
> written either as a single, double, or 32 frames.
> And this should be induced from card->ext_csd.rel_param, and not card-
> >ext_csd.rel_sectors.
This may change in the spec since this patch was written it was few years ago.
>
> > + .dev_id = (void *)cid,
> > + .dev_id_len = sizeof(cid),
> > + };
> > +
> > + /*
> > + * Provice CID as an octet array. The CID needs to be interpreted
> > + * when used as input to derive the RPMB key since some fields
> > + * will change due to firmware updates.
> > + */
> Not sure how the CID register is related to RPMB?
> Is this something internal to TEE?
Yes to identify the device.
>
> > + for (n = 0; n < 4; n++)
> > + cid[n] = be32_to_cpu(card->raw_cid[n]);
> > +
> > + list_for_each_entry(rpmb, &md->rpmbs, node) {
> > + rdev = rpmb_dev_register(&rpmb->dev, &descr);
> > + if (IS_ERR(rdev)) {
> > + pr_warn("%s: could not register RPMB device\n",
> > + dev_name(&rpmb->dev));
> > + continue;
> > + }
> > + rpmb->rdev = rdev;
> > + }
> > +}
> > +
>
> Thanks,
> Avri

2024-04-06 15:36:46

by Winkler, Tomas

[permalink] [raw]
Subject: RE: [PATCH v4 1/3] rpmb: add Replay Protected Memory Block (RPMB) subsystem



> -----Original Message-----
> From: Avri Altman <[email protected]>
> Sent: Saturday, April 6, 2024 1:27 PM
> To: Jens Wiklander <[email protected]>; linux-
> [email protected]; [email protected]; op-
> [email protected]
> Cc: Shyam Saini <[email protected]>; Ulf Hansson
> <[email protected]>; Linus Walleij <[email protected]>; Jerome
> Forissier <[email protected]>; Sumit Garg
> <[email protected]>; Ilias Apalodimas <[email protected]>;
> Bart Van Assche <[email protected]>; Randy Dunlap
> <[email protected]>; Ard Biesheuvel <[email protected]>; Arnd
> Bergmann <[email protected]>; Greg Kroah-Hartman
> <[email protected]>; Winkler, Tomas
> <[email protected]>; Alex Bennée <[email protected]>
> Subject: RE: [PATCH v4 1/3] rpmb: add Replay Protected Memory Block
> (RPMB) subsystem
>
> > A number of storage technologies support a specialised hardware
> > partition designed to be resistant to replay attacks. The underlying
> > HW protocols differ but the operations are common. The RPMB partition
> > cannot be accessed via standard block layer, but by a set of specific
> > RPMB commands: WRITE, READ, GET_WRITE_COUNTER, and
> PROGRAM_KEY.
> What about the other rpmb operations?
> There are 7 operations in eMMC.

There were only 4 at the time, now tot sure they are related to TEE needs.
>
> ............
>
> > +/**
> > + * rpmb_dev_find_device() - return first matching rpmb device
> > + * @data: data for the match function
> > + * @match: the matching function
> > + *
> > + * Iterate over registered RPMB devices, and call @match() for each
> > +passing
> > + * it the RPMB device and @data.
> > + *
> > + * The return value of @match() is checked for each call. If it
> > +returns
> > + * anything other 0, break and return the found RPMB device.
> > + *
> > + * It's the callers responsibility to call rpmb_dev_put() on the
> > +returned
> > + * device, when it's done with it.
> > + *
> > + * Returns: a matching rpmb device or NULL on failure */ struct
> > +rpmb_dev *rpmb_dev_find_device(const void *data,
> > + const struct rpmb_dev *start,
> > + int (*match)(struct rpmb_dev *rdev,
> > + const void *data))
> > +{
> > + struct rpmb_dev *rdev;
> > + struct list_head *pos;
> > +
> > + mutex_lock(&rpmb_mutex);
> > + if (start)
> > + pos = start->list_node.next;
> > + else
> > + pos = rpmb_dev_list.next;
> > +
> > + while (pos != &rpmb_dev_list) {
> Why not just list_for_each_entry
Yeah that may work
>
> > + rdev = container_of(pos, struct rpmb_dev, list_node);
> > + if (match(rdev, data)) {
> > + rpmb_dev_get(rdev);
> > + goto out;
> > + }
> > + pos = pos->next;
> > + }
> > + rdev = NULL;
> > +
> > +out:
> > + mutex_unlock(&rpmb_mutex);
> > +
> > + return rdev;
> > +}
>
> .....................
>
> > +/**
> > + * rpmb_dev_register - register RPMB partition with the RPMB
> > +subsystem
> > + * @dev: storage device of the rpmb device
> > + * @ops: device specific operations
> > + *
> > + * While registering the RPMB partition extract needed device
> > +information
> > + * while needed resources are available.
> > + *
> > + * Returns: a pointer to a 'struct rpmb_dev' or an ERR_PTR on failure
> > +*/ struct rpmb_dev *rpmb_dev_register(struct device *dev,
> > + struct rpmb_descr *descr) {
> > + struct rpmb_dev *rdev;
> > +
> > + if (!dev || !descr || !descr->route_frames || !descr->dev_id ||
> > + !descr->dev_id_len)
> > + return ERR_PTR(-EINVAL);
> > +
> > + rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
> > + if (!rdev)
> > + return ERR_PTR(-ENOMEM);
> > + rdev->descr = *descr;
> > + rdev->descr.dev_id = kmemdup(descr->dev_id, descr->dev_id_len,
> > + GFP_KERNEL);
> In addition to the dev_id, wouldn't it make sense to have your own IDA as
> well?
>
> > + if (!rdev->descr.dev_id) {
> > + kfree(rdev);
> > + return ERR_PTR(-ENOMEM);
> > + }
> > +
> > + rdev->parent_dev = dev;
> > +
> > + dev_dbg(rdev->parent_dev, "registered device\n");
> > +
> > + mutex_lock(&rpmb_mutex);
> > + list_add_tail(&rdev->list_node, &rpmb_dev_list);
> > + blocking_notifier_call_chain(&rpmb_interface,
> > RPMB_NOTIFY_ADD_DEVICE,
> > + rdev);
> > + mutex_unlock(&rpmb_mutex);
> > +
> > + return rdev;
> > +}
> > +EXPORT_SYMBOL_GPL(rpmb_dev_register);
>
> ............
>
> > new file mode 100644
> > index 000000000000..251d6b7e6d15
> > --- /dev/null
> > +++ b/include/linux/rpmb.h
> > @@ -0,0 +1,136 @@
> > +/* SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 */
> > +/*
> > + * Copyright (C) 2015-2019 Intel Corp. All rights reserved
> > + * Copyright (C) 2021-2022 Linaro Ltd */ #ifndef __RPMB_H__ #define
> > +__RPMB_H__
> > +
> > +#include <linux/types.h>
> > +#include <linux/device.h>
> > +#include <linux/notifier.h>
> > +
> > +/**
> > + * enum rpmb_type - type of underlying storage technology
> > + *
> > + * @RPMB_TYPE_EMMC : emmc (JESD84-B50.1)
> > + * @RPMB_TYPE_UFS : UFS (JESD220)
> > + * @RPMB_TYPE_NVME : NVM Express
> > + */
> > +enum rpmb_type {
> > + RPMB_TYPE_EMMC,
> > + RPMB_TYPE_UFS,
> > + RPMB_TYPE_NVME,
> > +};
> > +
> > +/**
> > + * struct rpmb_descr - RPMB descriptor provided by the underlying
> > +block
> > device
> The use of the term "rpmb descriptor" may be slightly misleading.
> This is because in UFS there are various descriptors that identifies various
> characteristics, e.g. device descriptor, geometry descriptor, unit descriptor
> etc., and recently UFS4.0 introduced a new descriptor - RPMB descriptor....

Might be overloaded, suggestions?


2024-04-08 09:09:25

by Linus Walleij

[permalink] [raw]
Subject: Re: [PATCH v4 2/3] mmc: block: register RPMB partition with the RPMB subsystem

Hi Jens,

On Fri, Apr 5, 2024 at 1:53 PM Jens Wiklander <[email protected]> wrote:

> +/**
> + * struct rpmb_frame - rpmb frame as defined by specs

As Tomas said maybe we can write the name of the spec or the number or
something so users can find it?

I would also write explicitly "the stuff bytes and big-endian properties are
modeled to fit to the spec".

Yours,
Linus Walleij

2024-04-09 08:39:41

by Jens Wiklander

[permalink] [raw]
Subject: Re: [PATCH v4 1/3] rpmb: add Replay Protected Memory Block (RPMB) subsystem

On Sat, Apr 6, 2024 at 12:27 PM Avri Altman <[email protected]> wrote:
>
> > A number of storage technologies support a specialised hardware
> > partition designed to be resistant to replay attacks. The underlying
> > HW protocols differ but the operations are common. The RPMB partition
> > cannot be accessed via standard block layer, but by a set of specific
> > RPMB commands: WRITE, READ, GET_WRITE_COUNTER, and PROGRAM_KEY.
> What about the other rpmb operations?
> There are 7 operations in eMMC.

I'm sorry, I don't have access to the spec currently. Do you have a
special operation in mind? Is it better to mention no operation since
UFS has even more operations?

>
> ............
>
> > +/**
> > + * rpmb_dev_find_device() - return first matching rpmb device
> > + * @data: data for the match function
> > + * @match: the matching function
> > + *
> > + * Iterate over registered RPMB devices, and call @match() for each passing
> > + * it the RPMB device and @data.
> > + *
> > + * The return value of @match() is checked for each call. If it returns
> > + * anything other 0, break and return the found RPMB device.
> > + *
> > + * It's the callers responsibility to call rpmb_dev_put() on the returned
> > + * device, when it's done with it.
> > + *
> > + * Returns: a matching rpmb device or NULL on failure
> > + */
> > +struct rpmb_dev *rpmb_dev_find_device(const void *data,
> > + const struct rpmb_dev *start,
> > + int (*match)(struct rpmb_dev *rdev,
> > + const void *data))
> > +{
> > + struct rpmb_dev *rdev;
> > + struct list_head *pos;
> > +
> > + mutex_lock(&rpmb_mutex);
> > + if (start)
> > + pos = start->list_node.next;
> > + else
> > + pos = rpmb_dev_list.next;
> > +
> > + while (pos != &rpmb_dev_list) {
> Why not just list_for_each_entry instead?

We want to continue from where we left off last time.

>
> > + rdev = container_of(pos, struct rpmb_dev, list_node);
> > + if (match(rdev, data)) {
> > + rpmb_dev_get(rdev);
> > + goto out;
> > + }
> > + pos = pos->next;
> > + }
> > + rdev = NULL;
> > +
> > +out:
> > + mutex_unlock(&rpmb_mutex);
> > +
> > + return rdev;
> > +}
>
> .....................
>
> > +/**
> > + * rpmb_dev_register - register RPMB partition with the RPMB subsystem
> > + * @dev: storage device of the rpmb device
> > + * @ops: device specific operations
> > + *
> > + * While registering the RPMB partition extract needed device information
> > + * while needed resources are available.
> > + *
> > + * Returns: a pointer to a 'struct rpmb_dev' or an ERR_PTR on failure
> > + */
> > +struct rpmb_dev *rpmb_dev_register(struct device *dev,
> > + struct rpmb_descr *descr)
> > +{
> > + struct rpmb_dev *rdev;
> > +
> > + if (!dev || !descr || !descr->route_frames || !descr->dev_id ||
> > + !descr->dev_id_len)
> > + return ERR_PTR(-EINVAL);
> > +
> > + rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
> > + if (!rdev)
> > + return ERR_PTR(-ENOMEM);
> > + rdev->descr = *descr;
> > + rdev->descr.dev_id = kmemdup(descr->dev_id, descr->dev_id_len,
> > + GFP_KERNEL);
> In addition to the dev_id, wouldn't it make sense to have your own IDA as well?

Currently, we don't need it.

>
> > + if (!rdev->descr.dev_id) {
> > + kfree(rdev);
> > + return ERR_PTR(-ENOMEM);
> > + }
> > +
> > + rdev->parent_dev = dev;
> > +
> > + dev_dbg(rdev->parent_dev, "registered device\n");
> > +
> > + mutex_lock(&rpmb_mutex);
> > + list_add_tail(&rdev->list_node, &rpmb_dev_list);
> > + blocking_notifier_call_chain(&rpmb_interface,
> > RPMB_NOTIFY_ADD_DEVICE,
> > + rdev);
> > + mutex_unlock(&rpmb_mutex);
> > +
> > + return rdev;
> > +}
> > +EXPORT_SYMBOL_GPL(rpmb_dev_register);
>
> ............
>
> > new file mode 100644
> > index 000000000000..251d6b7e6d15
> > --- /dev/null
> > +++ b/include/linux/rpmb.h
> > @@ -0,0 +1,136 @@
> > +/* SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 */
> > +/*
> > + * Copyright (C) 2015-2019 Intel Corp. All rights reserved
> > + * Copyright (C) 2021-2022 Linaro Ltd
> > + */
> > +#ifndef __RPMB_H__
> > +#define __RPMB_H__
> > +
> > +#include <linux/types.h>
> > +#include <linux/device.h>
> > +#include <linux/notifier.h>
> > +
> > +/**
> > + * enum rpmb_type - type of underlying storage technology
> > + *
> > + * @RPMB_TYPE_EMMC : emmc (JESD84-B50.1)
> > + * @RPMB_TYPE_UFS : UFS (JESD220)
> > + * @RPMB_TYPE_NVME : NVM Express
> > + */
> > +enum rpmb_type {
> > + RPMB_TYPE_EMMC,
> > + RPMB_TYPE_UFS,
> > + RPMB_TYPE_NVME,
> > +};
> > +
> > +/**
> > + * struct rpmb_descr - RPMB descriptor provided by the underlying block
> > device
> The use of the term "rpmb descriptor" may be slightly misleading.
> This is because in UFS there are various descriptors that identifies various characteristics,
> e.g. device descriptor, geometry descriptor, unit descriptor etc.,
> and recently UFS4.0 introduced a new descriptor - RPMB descriptor....

Would RPMB description be better? Or do you have some other idea?

Thanks,
Jens

2024-04-09 12:00:23

by Jens Wiklander

[permalink] [raw]
Subject: Re: [PATCH v4 2/3] mmc: block: register RPMB partition with the RPMB subsystem

On Sat, Apr 6, 2024 at 5:31 PM Winkler, Tomas <[email protected]> wrote:
>
> >
> >
> > > +
> > > +#define RPMB_PROGRAM_KEY 0x1 /* Program RPMB Authentication
> > You expect the key to be already programmed - so you don't really need this
> > operation?
> Depends in what manufacturing flow you program the device, second I believe in the original series was also a simulation device,
> This is important as the real device can be programmed only once.

This isn't strictly needed, this is the only "nice to have" feature
I've kept because it's easy enough and can be useful. I can remove it
if it's important.

> >
> > > Key */
> > > +#define RPMB_GET_WRITE_COUNTER 0x2 /* Read RPMB write counter
> > */
> > > +#define RPMB_WRITE_DATA 0x3 /* Write data to RPMB partition */
> > > +#define RPMB_READ_DATA 0x4 /* Read data from RPMB partition
> > */
> > > +#define RPMB_RESULT_READ 0x5 /* Read result request (Internal)
> > */
> > > +
> > > static DEFINE_MUTEX(block_mutex);
> > >
> > > /*
> > > @@ -163,6 +205,7 @@ struct mmc_rpmb_data {
> > > int id;
> > > unsigned int part_index;
> > > struct mmc_blk_data *md;
> > > + struct rpmb_dev *rdev;
> > > struct list_head node;
> > > };
> > >
> > > @@ -2672,7 +2715,6 @@ static int mmc_rpmb_chrdev_open(struct inode
> > > *inode, struct file *filp)
> > >
> > > get_device(&rpmb->dev);
> > > filp->private_data = rpmb;
> > > - mmc_blk_get(rpmb->md->disk);
> > Maybe add a comment that this has moved to mmc_blk_alloc_rpmb_part?
> > For those who will look for it.

Such a comment seems odd. Those looking for mmc_blk_get() should be
able to find it easily. I'll add the comment if it's important.

> >
> > >
> > > return nonseekable_open(inode, filp); } @@ -2682,7 +2724,6 @@
> > > static int mmc_rpmb_chrdev_release(struct inode *inode, struct file *filp)
> > > struct mmc_rpmb_data *rpmb = container_of(inode->i_cdev,
> > > struct
> > > mmc_rpmb_data, chrdev);
> > >
> > > - mmc_blk_put(rpmb->md);
> > Ditto.

See my answer above.

> >
> > > put_device(&rpmb->dev);
> > >
> > > return 0;
> > > @@ -2703,10 +2744,157 @@ static void
> > > mmc_blk_rpmb_device_release(struct
> > > device *dev) {
> > > struct mmc_rpmb_data *rpmb = dev_get_drvdata(dev);
> > >
> > > + rpmb_dev_unregister(rpmb->rdev);
> > > + mmc_blk_put(rpmb->md);
> > > ida_simple_remove(&mmc_rpmb_ida, rpmb->id);
> > > kfree(rpmb);
> > > }
> > >
> > > +static void free_idata(struct mmc_blk_ioc_data **idata, unsigned int
> > > +cmd_count) {
> > > + unsigned int n;
> > > +
> > > + for (n = 0; n < cmd_count; n++)
> > > + kfree(idata[n]);
> > > + kfree(idata);
> > > +}
> > > +
> > > +static struct mmc_blk_ioc_data **alloc_idata(struct mmc_rpmb_data
> > *rpmb,
> > > + unsigned int cmd_count) {
> > > + struct mmc_blk_ioc_data **idata;
> > > + unsigned int n;
> > > +
> > > + idata = kcalloc(cmd_count, sizeof(*idata), GFP_KERNEL);
> > > + if (!idata)
> > > + return NULL;
> > > +
> > > + for (n = 0; n < cmd_count; n++) {
> > > + idata[n] = kcalloc(1, sizeof(**idata), GFP_KERNEL);
> > > + if (!idata[n]) {
> > > + free_idata(idata, n);
> > > + return NULL;
> > > + }
> > > + idata[n]->rpmb = rpmb;
> > > + }
> > > +
> > > + return idata;
> > > +}
> > > +
> > > +static void set_idata(struct mmc_blk_ioc_data *idata, u32 opcode,
> > > + int write_flag, u8 *buf, unsigned int buf_bytes) {
> > > + idata->ic.opcode = opcode;
> > > + idata->ic.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
> > > + idata->ic.write_flag = write_flag;
> > > + idata->ic.blksz = sizeof(struct rpmb_frame);
> > blksz = 512, so maybe add a compile-time check on sizeof(struct
> > rpmb_frame)?

That makes sense, I'll add it.

> >
> > > + idata->ic.blocks = buf_bytes / idata->ic.blksz;
> > > + idata->buf = buf;
> > > + idata->buf_bytes = buf_bytes;
> > > +}
> > > +
> > > +static int mmc_route_rpmb_frames(struct device *dev, u8 *req,
> > > + unsigned int req_len, u8 *resp,
> > > + unsigned int resp_len) {
> > > + struct rpmb_frame *frm = (struct rpmb_frame *)req;
> > > + struct mmc_rpmb_data *rpmb = dev_get_drvdata(dev);
> > > + struct mmc_blk_data *md = rpmb->md;
> > > + struct mmc_blk_ioc_data **idata;
> > > + unsigned int cmd_count;
> > > + struct request *rq;
> > > + u16 req_type;
> > > + bool write;
> > > + int ret;
> > > +
> > > + if (IS_ERR(md->queue.card))
> > > + return PTR_ERR(md->queue.card);
> > > +
> > > + if (req_len < sizeof(*frm))
> > > + return -EINVAL;
> > > +
> > > + req_type = be16_to_cpu(frm->req_resp);
> > > + switch (req_type) {
> > > + case RPMB_PROGRAM_KEY:
> > > + if (req_len != sizeof(struct rpmb_frame) ||
> > > + resp_len != sizeof(struct rpmb_frame))
> > > + return -EINVAL;
> > > + write = true;
> > > + break;
> > > + case RPMB_GET_WRITE_COUNTER:
> > > + if (req_len != sizeof(struct rpmb_frame) ||
> > > + resp_len != sizeof(struct rpmb_frame))
> > > + return -EINVAL;
> > > + write = false;
> > > + break;
> > > + case RPMB_WRITE_DATA:
> > > + if (req_len % sizeof(struct rpmb_frame) ||
> > > + resp_len != sizeof(struct rpmb_frame))
> > > + return -EINVAL;
> > > + write = true;
> > > + break;
> > > + case RPMB_READ_DATA:
> > > + if (req_len != sizeof(struct rpmb_frame) ||
> > > + resp_len % sizeof(struct rpmb_frame))
> > > + return -EINVAL;
> > > + write = false;
> > > + break;
> > > + default:
> > > + return -EINVAL;
> > > + }
> > Looks like the above input validation section can be reduced to is
> > RPMB_WRITE_DATA and default?

RPMB_GET_WRITE_COUNTER and RPMB_READ_DATA have different checks for resp_len.

> >
> > > +
> > > + if (write)
> > > + cmd_count = 3;
> > > + else
> > > + cmd_count = 2;
> > > +
> > > + idata = alloc_idata(rpmb, cmd_count);
> > > + if (!idata)
> > > + return -ENOMEM;
> > > +
> > > + if (write) {
> > > + struct rpmb_frame *frm = (struct rpmb_frame *)resp;
> > > +
> > > + /* Send write request frame(s) */
> > > + set_idata(idata[0], MMC_WRITE_MULTIPLE_BLOCK,
> > > + 1 | MMC_CMD23_ARG_REL_WR, req, req_len);
> > > +
> > > + /* Send result request frame */
> > > + memset(frm, 0, sizeof(*frm));
> > > + frm->req_resp = cpu_to_be16(RPMB_RESULT_READ);
> > > + set_idata(idata[1], MMC_WRITE_MULTIPLE_BLOCK, 1, resp,
> > > + resp_len);
> > > +
> > > + /* Read response frame */
> > > + set_idata(idata[2], MMC_READ_MULTIPLE_BLOCK, 0, resp,
> > > resp_len);
> > It is confusing to me that your response is holding 2 frame types:
> > The status frame and the response frame.
> Refer to the spec.
>
> >
> >
> > > + } else {
> > > + /* Send write request frame(s) */
> > > + set_idata(idata[0], MMC_WRITE_MULTIPLE_BLOCK, 1, req,
> > > + req_len);
> > > +
> > > + /* Read response frame */
> > > + set_idata(idata[1], MMC_READ_MULTIPLE_BLOCK, 0, resp,
> > > resp_len);
> > > + }
> > > +
> > > + rq = blk_mq_alloc_request(md->queue.queue, REQ_OP_DRV_OUT,
> > 0);
> > > + if (IS_ERR(rq)) {
> > > + ret = PTR_ERR(rq);
> > > + goto out;
> > > + }
> > > +
> > > + req_to_mmc_queue_req(rq)->drv_op =
> > MMC_DRV_OP_IOCTL_RPMB;
> > > + req_to_mmc_queue_req(rq)->drv_op_result = -EIO;
> > > + req_to_mmc_queue_req(rq)->drv_op_data = idata;
> > > + req_to_mmc_queue_req(rq)->ioc_count = cmd_count;
> > Maybe have an additional struct mmc_queue_req *mq_rq =
> > req_to_mmc_queue_req(rq);

Sure, I'll add it.

> >
> > > + blk_execute_rq(rq, false);
> > > + ret = req_to_mmc_queue_req(rq)->drv_op_result;
> > > +
> > > + blk_mq_free_request(rq);
> > > +
> > > +out:
> > > + free_idata(idata, cmd_count);
> > > + return ret;
> > > +}
> > > +
> > > static int mmc_blk_alloc_rpmb_part(struct mmc_card *card,
> > > struct mmc_blk_data *md,
> > > unsigned int part_index, @@ -2741,6
> > > +2929,7 @@ static int mmc_blk_alloc_rpmb_part(struct mmc_card *card,
> > > rpmb->dev.release = mmc_blk_rpmb_device_release;
> > > device_initialize(&rpmb->dev);
> > > dev_set_drvdata(&rpmb->dev, rpmb);
> > > + mmc_blk_get(md->disk);
> > > rpmb->md = md;
> > >
> > > cdev_init(&rpmb->chrdev, &mmc_rpmb_fileops); @@ -3002,6
> > > +3191,41 @@ static void mmc_blk_remove_debugfs(struct mmc_card
> > *card,
> > >
> > > #endif /* CONFIG_DEBUG_FS */
> > >
> > > +static void mmc_blk_rpmb_add(struct mmc_card *card) {
> > > + struct mmc_blk_data *md = dev_get_drvdata(&card->dev);
> > > + struct mmc_rpmb_data *rpmb;
> > > + struct rpmb_dev *rdev;
> > > + unsigned int n;
> > > + u32 cid[4];
> > > + struct rpmb_descr descr = {
> > > + .type = RPMB_TYPE_EMMC,
> > > + .route_frames = mmc_route_rpmb_frames,
> > > + .reliable_wr_count = card->ext_csd.raw_rpmb_size_mult,
> > > + .capacity = card->ext_csd.rel_sectors,
> > The capacity is RPMB_SIZE_MULT and also limited to 16MB?

Thanks for noticing this, I'll fix it. Yes, the spec says it's limited to 16MB.

> > And you also need the region size you are writing to.
> > If I get your intention regarding reliable_wr_count, AFAIK, rpmb can be
> > written either as a single, double, or 32 frames.
> > And this should be induced from card->ext_csd.rel_param, and not card-
> > >ext_csd.rel_sectors.
> This may change in the spec since this patch was written it was few years ago.

Thanks, I'll fix it.

> >
> > > + .dev_id = (void *)cid,
> > > + .dev_id_len = sizeof(cid),
> > > + };
> > > +
> > > + /*
> > > + * Provice CID as an octet array. The CID needs to be interpreted
> > > + * when used as input to derive the RPMB key since some fields
> > > + * will change due to firmware updates.
> > > + */
> > Not sure how the CID register is related to RPMB?
> > Is this something internal to TEE?
> Yes to identify the device.

+1

Thanks,
Jens

> >
> > > + for (n = 0; n < 4; n++)
> > > + cid[n] = be32_to_cpu(card->raw_cid[n]);
> > > +
> > > + list_for_each_entry(rpmb, &md->rpmbs, node) {
> > > + rdev = rpmb_dev_register(&rpmb->dev, &descr);
> > > + if (IS_ERR(rdev)) {
> > > + pr_warn("%s: could not register RPMB device\n",
> > > + dev_name(&rpmb->dev));
> > > + continue;
> > > + }
> > > + rpmb->rdev = rdev;
> > > + }
> > > +}
> > > +
> >
> > Thanks,
> > Avri

2024-04-09 12:01:29

by Jens Wiklander

[permalink] [raw]
Subject: Re: [PATCH v4 2/3] mmc: block: register RPMB partition with the RPMB subsystem

Hi Linus,

On Mon, Apr 8, 2024 at 11:07 AM Linus Walleij <linus.walleij@linaroorg> wrote:
>
> Hi Jens,
>
> On Fri, Apr 5, 2024 at 1:53 PM Jens Wiklander <[email protected]> wrote:
>
> > +/**
> > + * struct rpmb_frame - rpmb frame as defined by specs
>
> As Tomas said maybe we can write the name of the spec or the number or
> something so users can find it?
>
> I would also write explicitly "the stuff bytes and big-endian properties are
> modeled to fit to the spec".

That makes sense, I'll add it.

Thanks,
Jens

>
> Yours,
> Linus Walleij

2024-04-10 10:48:55

by Sumit Garg

[permalink] [raw]
Subject: Re: [PATCH v4 3/3] optee: probe RPMB device using RPMB subsystem

Hi Jens,

On Fri, 5 Apr 2024 at 17:23, Jens Wiklander <[email protected]> wrote:
>
> Adds support in the OP-TEE drivers (both SMC and FF-A ABIs) to probe and
> use an RPMB device via the RPBM subsystem instead of passing the RPMB

s/RPBM/RPMB/

> frames via tee-supplicant in user space. A fallback mechanism is kept to
> route RPMB frames via tee-supplicant if the RPMB subsystem isn't
> available.
>
> The OP-TEE RPC ABI is extended to support iterating over all RPMB
> devices until one is found with the expected RPMB key already
> programmed.
>
> Signed-off-by: Jens Wiklander <[email protected]>
> ---
> drivers/tee/optee/core.c | 30 ++++
> drivers/tee/optee/device.c | 7 +
> drivers/tee/optee/ffa_abi.c | 8 +
> drivers/tee/optee/optee_private.h | 21 ++-
> drivers/tee/optee/optee_rpc_cmd.h | 35 +++++
> drivers/tee/optee/rpc.c | 233 ++++++++++++++++++++++++++++++
> drivers/tee/optee/smc_abi.c | 7 +
> 7 files changed, 340 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
> index 3aed554bc8d8..082691c10a90 100644
> --- a/drivers/tee/optee/core.c
> +++ b/drivers/tee/optee/core.c
> @@ -11,6 +11,7 @@
> #include <linux/io.h>
> #include <linux/mm.h>
> #include <linux/module.h>
> +#include <linux/rpmb.h>
> #include <linux/slab.h>
> #include <linux/string.h>
> #include <linux/tee_drv.h>
> @@ -80,6 +81,31 @@ void optee_pool_op_free_helper(struct tee_shm_pool *pool, struct tee_shm *shm,
> shm->pages = NULL;
> }
>
> +void optee_bus_scan_rpmb(struct work_struct *work)
> +{
> + struct optee *optee = container_of(work, struct optee,
> + rpmb_scan_bus_work);
> + int ret;
> +
> + if (!optee->rpmb_scan_bus_done) {
> + ret = optee_enumerate_devices(PTA_CMD_GET_DEVICES_RPMB);
> + optee->rpmb_scan_bus_done = !ret;
> + if (ret && ret != -ENODEV)
> + pr_info("Scanning for RPMB device: ret %d\n", ret);
> + }
> +}
> +
> +int optee_rpmb_intf_rdev(struct notifier_block *intf, unsigned long action,
> + void *data)
> +{
> + struct optee *optee = container_of(intf, struct optee, rpmb_intf);
> +
> + if (action == RPMB_NOTIFY_ADD_DEVICE)
> + schedule_work(&optee->rpmb_scan_bus_work);
> +
> + return 0;
> +}
> +
> static void optee_bus_scan(struct work_struct *work)
> {
> WARN_ON(optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP));
> @@ -161,6 +187,8 @@ void optee_release_supp(struct tee_context *ctx)
>
> void optee_remove_common(struct optee *optee)
> {
> + rpmb_interface_unregister(&optee->rpmb_intf);
> + cancel_work_sync(&optee->rpmb_scan_bus_work);
> /* Unregister OP-TEE specific client devices on TEE bus */
> optee_unregister_devices();
>
> @@ -177,6 +205,8 @@ void optee_remove_common(struct optee *optee)
> tee_shm_pool_free(optee->pool);
> optee_supp_uninit(&optee->supp);
> mutex_destroy(&optee->call_queue.mutex);
> + rpmb_dev_put(optee->rpmb_dev);
> + mutex_destroy(&optee->rpmb_dev_mutex);
> }
>
> static int smc_abi_rc;
> diff --git a/drivers/tee/optee/device.c b/drivers/tee/optee/device.c
> index 4b1092127694..4274876857c8 100644
> --- a/drivers/tee/optee/device.c
> +++ b/drivers/tee/optee/device.c
> @@ -43,6 +43,13 @@ static int get_devices(struct tee_context *ctx, u32 session,
> ret = tee_client_invoke_func(ctx, &inv_arg, param);
> if ((ret < 0) || ((inv_arg.ret != TEEC_SUCCESS) &&
> (inv_arg.ret != TEEC_ERROR_SHORT_BUFFER))) {
> + /*
> + * TEE_ERROR_STORAGE_NOT_AVAILABLE is returned when getting
> + * the list of device TAs that depends on RPMB but a usable
> + * RPMB device isn't found.
> + */
> + if (inv_arg.ret == TEE_ERROR_STORAGE_NOT_AVAILABLE)
> + return -ENODEV;
> pr_err("PTA_CMD_GET_DEVICES invoke function err: %x\n",
> inv_arg.ret);
> return -EINVAL;
> diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c
> index ecb5eb079408..a8dfdb30b4e8 100644
> --- a/drivers/tee/optee/ffa_abi.c
> +++ b/drivers/tee/optee/ffa_abi.c
> @@ -7,6 +7,7 @@
>
> #include <linux/arm_ffa.h>
> #include <linux/errno.h>
> +#include <linux/rpmb.h>
> #include <linux/scatterlist.h>
> #include <linux/sched.h>
> #include <linux/slab.h>
> @@ -934,6 +935,7 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
> optee_cq_init(&optee->call_queue, 0);
> optee_supp_init(&optee->supp);
> optee_shm_arg_cache_init(optee, arg_cache_flags);
> + mutex_init(&optee->rpmb_dev_mutex);
> ffa_dev_set_drvdata(ffa_dev, optee);
> ctx = teedev_open(optee->teedev);
> if (IS_ERR(ctx)) {
> @@ -955,6 +957,9 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
> if (rc)
> goto err_unregister_devices;
>
> + INIT_WORK(&optee->rpmb_scan_bus_work, optee_bus_scan_rpmb);
> + optee->rpmb_intf.notifier_call = optee_rpmb_intf_rdev;
> + rpmb_interface_register(&optee->rpmb_intf);
> pr_info("initialized driver\n");
> return 0;
>
> @@ -968,6 +973,9 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
> teedev_close_context(ctx);
> err_rhashtable_free:
> rhashtable_free_and_destroy(&optee->ffa.global_ids, rh_free_fn, NULL);
> + rpmb_dev_put(optee->rpmb_dev);
> + mutex_destroy(&optee->rpmb_dev_mutex);
> + rpmb_interface_unregister(&optee->rpmb_intf);
> optee_supp_uninit(&optee->supp);
> mutex_destroy(&optee->call_queue.mutex);
> mutex_destroy(&optee->ffa.mutex);
> diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
> index 7a5243c78b55..ae72f3dda1d2 100644
> --- a/drivers/tee/optee/optee_private.h
> +++ b/drivers/tee/optee/optee_private.h
> @@ -8,6 +8,7 @@
>
> #include <linux/arm-smccc.h>
> #include <linux/rhashtable.h>
> +#include <linux/rpmb.h>
> #include <linux/semaphore.h>
> #include <linux/tee_drv.h>
> #include <linux/types.h>
> @@ -20,11 +21,13 @@
> /* Some Global Platform error codes used in this driver */
> #define TEEC_SUCCESS 0x00000000
> #define TEEC_ERROR_BAD_PARAMETERS 0xFFFF0006
> +#define TEEC_ERROR_ITEM_NOT_FOUND 0xFFFF0008
> #define TEEC_ERROR_NOT_SUPPORTED 0xFFFF000A
> #define TEEC_ERROR_COMMUNICATION 0xFFFF000E
> #define TEEC_ERROR_OUT_OF_MEMORY 0xFFFF000C
> #define TEEC_ERROR_BUSY 0xFFFF000D
> #define TEEC_ERROR_SHORT_BUFFER 0xFFFF0010
> +#define TEE_ERROR_STORAGE_NOT_AVAILABLE 0xF0100003
>
> #define TEEC_ORIGIN_COMMS 0x00000002
>
> @@ -197,6 +200,12 @@ struct optee_ops {
> * @notif: notification synchronization struct
> * @supp: supplicant synchronization struct for RPC to supplicant
> * @pool: shared memory pool
> + * @mutex: mutex protecting @rpmb_dev
> + * @rpmb_dev: current RPMB device or NULL
> + * @rpmb_scan_bus_done flag if device registation of RPMB dependent devices
> + * was already done
> + * @rpmb_scan_bus_work workq to for an RPMB device and to scan optee bus
> + * and register RPMB dependent optee drivers
> * @rpc_param_count: If > 0 number of RPC parameters to make room for
> * @scan_bus_done flag if device registation was already done.
> * @scan_bus_work workq to scan optee bus and register optee drivers
> @@ -215,9 +224,15 @@ struct optee {
> struct optee_notif notif;
> struct optee_supp supp;
> struct tee_shm_pool *pool;
> + /* Protects rpmb_dev pointer */
> + struct mutex rpmb_dev_mutex;
> + struct rpmb_dev *rpmb_dev;
> + struct notifier_block rpmb_intf;
> unsigned int rpc_param_count;
> - bool scan_bus_done;
> + bool scan_bus_done;
> + bool rpmb_scan_bus_done;
> struct work_struct scan_bus_work;
> + struct work_struct rpmb_scan_bus_work;
> };
>
> struct optee_session {
> @@ -280,8 +295,12 @@ int optee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session);
>
> #define PTA_CMD_GET_DEVICES 0x0
> #define PTA_CMD_GET_DEVICES_SUPP 0x1
> +#define PTA_CMD_GET_DEVICES_RPMB 0x2
> int optee_enumerate_devices(u32 func);
> void optee_unregister_devices(void);
> +void optee_bus_scan_rpmb(struct work_struct *work);
> +int optee_rpmb_intf_rdev(struct notifier_block *intf, unsigned long action,
> + void *data);
>
> int optee_pool_op_alloc_helper(struct tee_shm_pool *pool, struct tee_shm *shm,
> size_t size, size_t align,
> diff --git a/drivers/tee/optee/optee_rpc_cmd.h b/drivers/tee/optee/optee_rpc_cmd.h
> index f3f06e0994a7..f351a8ac69fc 100644
> --- a/drivers/tee/optee/optee_rpc_cmd.h
> +++ b/drivers/tee/optee/optee_rpc_cmd.h
> @@ -16,6 +16,14 @@
> * and sends responses.
> */
>
> +/*
> + * Replay Protected Memory Block access
> + *
> + * [in] memref[0] Frames to device
> + * [out] memref[1] Frames from device
> + */
> +#define OPTEE_RPC_CMD_RPMB 1
> +
> /*
> * Get time
> *
> @@ -103,4 +111,31 @@
> /* I2C master control flags */
> #define OPTEE_RPC_I2C_FLAGS_TEN_BIT BIT(0)
>
> +/*
> + * Reset RPMB probing
> + *
> + * Releases an eventually already used RPMB devices and starts over searching
> + * for RPMB devices. Returns the kind of shared memory to use in subsequent
> + * OPTEE_RPC_CMD_RPMB_PROBE_NEXT and OPTEE_RPC_CMD_RPMB calls.
> + *
> + * [out] value[0].a OPTEE_RPC_SHM_TYPE_*, the parameter for
> + * OPTEE_RPC_CMD_SHM_ALLOC
> + */
> +#define OPTEE_RPC_CMD_RPMB_PROBE_RESET 22
> +

AFAICS from [1], this RPMB reset probing is only used to check if the
kernel supports RPMB probing or not. I suppose that should be detected
via a single RPC call like: OPTEE_RPC_CMD_RPMB_PROBE. Other than that
the shared memory allocation type can be used as
THREAD_SHM_TYPE_KERNEL_PRIVATE if OPTEE_RPC_CMD_RPMB_PROBE works
otherwise THREAD_SHM_TYPE_APPLICATION can be used for legacy RPMB init
via tee-supplicant.

Is there any other specific scenario I am missing which requires an
explicit RPMB probe reset call?

[1] https://github.com/jenswi-linaro/optee_os/commit/50ed7324411e3bdf7dba702d75eb0dbedda1c5cd

-Sumit

> +/*
> + * Probe next RPMB device
> + *
> + * [out] value[0].a Type of RPMB device, OPTEE_RPC_RPMB_*
> + * [out] value[0].b EXT CSD-slice 168 "RPMB Size"
> + * [out] value[0].c EXT CSD-slice 222 "Reliable Write Sector Count"
> + * [out] memref[1] Buffer with the raw CID
> + */
> +#define OPTEE_RPC_CMD_RPMB_PROBE_NEXT 23
> +
> +/* Type of RPMB device */
> +#define OPTEE_RPC_RPMB_EMMC 0
> +#define OPTEE_RPC_RPMB_UFS 1
> +#define OPTEE_RPC_RPMB_NVME 2
> +
> #endif /*__OPTEE_RPC_CMD_H*/
> diff --git a/drivers/tee/optee/rpc.c b/drivers/tee/optee/rpc.c
> index e69bc6380683..e211c1c94984 100644
> --- a/drivers/tee/optee/rpc.c
> +++ b/drivers/tee/optee/rpc.c
> @@ -7,6 +7,7 @@
>
> #include <linux/delay.h>
> #include <linux/i2c.h>
> +#include <linux/rpmb.h>
> #include <linux/slab.h>
> #include <linux/tee_drv.h>
> #include "optee_private.h"
> @@ -255,6 +256,229 @@ void optee_rpc_cmd_free_suppl(struct tee_context *ctx, struct tee_shm *shm)
> optee_supp_thrd_req(ctx, OPTEE_RPC_CMD_SHM_FREE, 1, &param);
> }
>
> +static void handle_rpc_func_rpmb_probe_reset(struct tee_context *ctx,
> + struct optee *optee,
> + struct optee_msg_arg *arg)
> +{
> + struct tee_param params[1];
> +
> + if (!IS_ENABLED(CONFIG_RPMB)) {
> + handle_rpc_supp_cmd(ctx, optee, arg);
> + return;
> + }
> +
> + if (arg->num_params != ARRAY_SIZE(params) ||
> + optee->ops->from_msg_param(optee, params, arg->num_params,
> + arg->params) ||
> + params[0].attr != TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT) {
> + arg->ret = TEEC_ERROR_BAD_PARAMETERS;
> + return;
> + }
> +
> + params[0].u.value.a = OPTEE_RPC_SHM_TYPE_KERNEL;
> + params[0].u.value.b = 0;
> + params[0].u.value.c = 0;
> + if (optee->ops->to_msg_param(optee, arg->params,
> + arg->num_params, params)) {
> + arg->ret = TEEC_ERROR_BAD_PARAMETERS;
> + return;
> + }
> +
> + mutex_lock(&optee->rpmb_dev_mutex);
> + rpmb_dev_put(optee->rpmb_dev);
> + optee->rpmb_dev = NULL;
> + mutex_unlock(&optee->rpmb_dev_mutex);
> +
> + arg->ret = TEEC_SUCCESS;
> +}
> +
> +static int rpmb_type_to_rpc_type(enum rpmb_type rtype)
> +{
> + switch (rtype) {
> + case RPMB_TYPE_EMMC:
> + return OPTEE_RPC_RPMB_EMMC;
> + case RPMB_TYPE_UFS:
> + return OPTEE_RPC_RPMB_UFS;
> + case RPMB_TYPE_NVME:
> + return OPTEE_RPC_RPMB_NVME;
> + default:
> + return -1;
> + }
> +}
> +
> +static int rpc_rpmb_match(struct rpmb_dev *rdev, const void *data)
> +{
> + return rpmb_type_to_rpc_type(rdev->descr.type) >= 0;
> +}
> +
> +static void handle_rpc_func_rpmb_probe_next(struct tee_context *ctx,
> + struct optee *optee,
> + struct optee_msg_arg *arg)
> +{
> + struct rpmb_dev *rdev;
> + struct tee_param params[2];
> + void *buf;
> +
> + if (!IS_REACHABLE(CONFIG_RPMB)) {
> + handle_rpc_supp_cmd(ctx, optee, arg);
> + return;
> + }
> +
> + if (arg->num_params != ARRAY_SIZE(params) ||
> + optee->ops->from_msg_param(optee, params, arg->num_params,
> + arg->params) ||
> + params[0].attr != TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT ||
> + params[1].attr != TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT) {
> + arg->ret = TEEC_ERROR_BAD_PARAMETERS;
> + return;
> + }
> + buf = tee_shm_get_va(params[1].u.memref.shm,
> + params[1].u.memref.shm_offs);
> + if (!buf) {
> + arg->ret = TEEC_ERROR_BAD_PARAMETERS;
> + return;
> + }
> +
> + mutex_lock(&optee->rpmb_dev_mutex);
> + rdev = rpmb_dev_find_device(NULL, optee->rpmb_dev, rpc_rpmb_match);
> + rpmb_dev_put(optee->rpmb_dev);
> + optee->rpmb_dev = rdev;
> + mutex_unlock(&optee->rpmb_dev_mutex);
> +
> + if (!rdev) {
> + arg->ret = TEEC_ERROR_ITEM_NOT_FOUND;
> + return;
> + }
> +
> + if (params[1].u.memref.size < rdev->descr.dev_id_len) {
> + arg->ret = TEEC_ERROR_SHORT_BUFFER;
> + return;
> + }
> + memcpy(buf, rdev->descr.dev_id, rdev->descr.dev_id_len);
> + params[1].u.memref.size = rdev->descr.dev_id_len;
> + params[0].u.value.a = rpmb_type_to_rpc_type(rdev->descr.type);
> + params[0].u.value.b = rdev->descr.capacity;
> + params[0].u.value.c = rdev->descr.reliable_wr_count;
> + if (optee->ops->to_msg_param(optee, arg->params,
> + arg->num_params, params)) {
> + arg->ret = TEEC_ERROR_BAD_PARAMETERS;
> + return;
> + }
> +
> + arg->ret = TEEC_SUCCESS;
> +}
> +
> +/* Request */
> +struct rpmb_req {
> + u16 cmd;
> +#define RPMB_CMD_DATA_REQ 0x00
> +#define RPMB_CMD_GET_DEV_INFO 0x01
> + u16 dev_id;
> + u16 block_count;
> + /* Optional data frames (rpmb_data_frame) follow */
> +};
> +
> +#define RPMB_REQ_DATA(req) ((void *)((struct rpmb_req *)(req) + 1))
> +
> +#define RPMB_CID_SZ 16
> +
> +/* Response to device info request */
> +struct rpmb_dev_info {
> + u8 cid[RPMB_CID_SZ];
> + u8 rpmb_size_mult; /* EXT CSD-slice 168: RPMB Size */
> + u8 rel_wr_sec_c; /* EXT CSD-slice 222: Reliable Write Sector */
> + /* Count */
> + u8 ret_code;
> +#define RPMB_CMD_GET_DEV_INFO_RET_OK 0x00
> +#define RPMB_CMD_GET_DEV_INFO_RET_ERROR 0x01
> +};
> +
> +static int get_dev_info(struct rpmb_dev *rdev, void *rsp, size_t rsp_size)
> +{
> + struct rpmb_dev_info *dev_info;
> +
> + if (rsp_size != sizeof(*dev_info))
> + return TEEC_ERROR_BAD_PARAMETERS;
> +
> + dev_info = rsp;
> + memcpy(dev_info->cid, rdev->descr.dev_id, sizeof(dev_info->cid));
> + dev_info->rpmb_size_mult = rdev->descr.capacity;
> + dev_info->rel_wr_sec_c = rdev->descr.reliable_wr_count;
> + dev_info->ret_code = RPMB_CMD_GET_DEV_INFO_RET_OK;
> +
> + return TEEC_SUCCESS;
> +}
> +
> +/*
> + * req is one struct rpmb_req followed by one or more struct rpmb_data_frame
> + * rsp is either one struct rpmb_dev_info or one or more struct rpmb_data_frame
> + */
> +static u32 rpmb_process_request(struct optee *optee, struct rpmb_dev *rdev,
> + void *req, size_t req_size,
> + void *rsp, size_t rsp_size)
> +{
> + struct rpmb_req *sreq = req;
> + int rc;
> +
> + if (req_size < sizeof(*sreq))
> + return TEEC_ERROR_BAD_PARAMETERS;
> +
> + switch (sreq->cmd) {
> + case RPMB_CMD_DATA_REQ:
> + rc = rpmb_route_frames(rdev, RPMB_REQ_DATA(req),
> + req_size - sizeof(struct rpmb_req),
> + rsp, rsp_size);
> + if (rc)
> + return TEEC_ERROR_BAD_PARAMETERS;
> + return TEEC_SUCCESS;
> + case RPMB_CMD_GET_DEV_INFO:
> + return get_dev_info(rdev, rsp, rsp_size);
> + default:
> + return TEEC_ERROR_BAD_PARAMETERS;
> + }
> +}
> +
> +static void handle_rpc_func_rpmb(struct tee_context *ctx, struct optee *optee,
> + struct optee_msg_arg *arg)
> +{
> + struct tee_param params[2];
> + struct rpmb_dev *rdev;
> + void *p0, *p1;
> +
> + mutex_lock(&optee->rpmb_dev_mutex);
> + rdev = rpmb_dev_get(optee->rpmb_dev);
> + mutex_unlock(&optee->rpmb_dev_mutex);
> + if (!rdev) {
> + handle_rpc_supp_cmd(ctx, optee, arg);
> + return;
> + }
> +
> + if (arg->num_params != ARRAY_SIZE(params) ||
> + optee->ops->from_msg_param(optee, params, arg->num_params,
> + arg->params) ||
> + params[0].attr != TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT ||
> + params[1].attr != TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT) {
> + arg->ret = TEEC_ERROR_BAD_PARAMETERS;
> + goto out;
> + }
> +
> + p0 = tee_shm_get_va(params[0].u.memref.shm,
> + params[0].u.memref.shm_offs);
> + p1 = tee_shm_get_va(params[1].u.memref.shm,
> + params[1].u.memref.shm_offs);
> + arg->ret = rpmb_process_request(optee, rdev, p0,
> + params[0].u.memref.size,
> + p1, params[1].u.memref.size);
> + if (arg->ret)
> + goto out;
> +
> + if (optee->ops->to_msg_param(optee, arg->params,
> + arg->num_params, params))
> + arg->ret = TEEC_ERROR_BAD_PARAMETERS;
> +out:
> + rpmb_dev_put(rdev);
> +}
> +
> void optee_rpc_cmd(struct tee_context *ctx, struct optee *optee,
> struct optee_msg_arg *arg)
> {
> @@ -271,6 +495,15 @@ void optee_rpc_cmd(struct tee_context *ctx, struct optee *optee,
> case OPTEE_RPC_CMD_I2C_TRANSFER:
> handle_rpc_func_cmd_i2c_transfer(ctx, arg);
> break;
> + case OPTEE_RPC_CMD_RPMB_PROBE_RESET:
> + handle_rpc_func_rpmb_probe_reset(ctx, optee, arg);
> + break;
> + case OPTEE_RPC_CMD_RPMB_PROBE_NEXT:
> + handle_rpc_func_rpmb_probe_next(ctx, optee, arg);
> + break;
> + case OPTEE_RPC_CMD_RPMB:
> + handle_rpc_func_rpmb(ctx, optee, arg);
> + break;
> default:
> handle_rpc_supp_cmd(ctx, optee, arg);
> }
> diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c
> index a37f87087e5c..c23bcf35c8cb 100644
> --- a/drivers/tee/optee/smc_abi.c
> +++ b/drivers/tee/optee/smc_abi.c
> @@ -20,6 +20,7 @@
> #include <linux/of_irq.h>
> #include <linux/of_platform.h>
> #include <linux/platform_device.h>
> +#include <linux/rpmb.h>
> #include <linux/sched.h>
> #include <linux/slab.h>
> #include <linux/string.h>
> @@ -1715,6 +1716,7 @@ static int optee_probe(struct platform_device *pdev)
> optee->smc.memremaped_shm = memremaped_shm;
> optee->pool = pool;
> optee_shm_arg_cache_init(optee, arg_cache_flags);
> + mutex_init(&optee->rpmb_dev_mutex);
>
> platform_set_drvdata(pdev, optee);
> ctx = teedev_open(optee->teedev);
> @@ -1769,6 +1771,9 @@ static int optee_probe(struct platform_device *pdev)
> if (rc)
> goto err_disable_shm_cache;
>
> + INIT_WORK(&optee->rpmb_scan_bus_work, optee_bus_scan_rpmb);
> + optee->rpmb_intf.notifier_call = optee_rpmb_intf_rdev;
> + rpmb_interface_register(&optee->rpmb_intf);
> pr_info("initialized driver\n");
> return 0;
>
> @@ -1782,6 +1787,8 @@ static int optee_probe(struct platform_device *pdev)
> err_close_ctx:
> teedev_close_context(ctx);
> err_supp_uninit:
> + rpmb_dev_put(optee->rpmb_dev);
> + mutex_destroy(&optee->rpmb_dev_mutex);
> optee_shm_arg_cache_uninit(optee);
> optee_supp_uninit(&optee->supp);
> mutex_destroy(&optee->call_queue.mutex);
> --
> 2.34.1
>

2024-04-11 06:53:44

by Jens Wiklander

[permalink] [raw]
Subject: Re: [PATCH v4 3/3] optee: probe RPMB device using RPMB subsystem

Hi Sumit,

On Wed, Apr 10, 2024 at 12:48 PM Sumit Garg <[email protected]> wrote:
>
> Hi Jens,
>
> On Fri, 5 Apr 2024 at 17:23, Jens Wiklander <[email protected]> wrote:
> >
> > Adds support in the OP-TEE drivers (both SMC and FF-A ABIs) to probe and
> > use an RPMB device via the RPBM subsystem instead of passing the RPMB
>
> s/RPBM/RPMB/

Thanks, I'll fix it.

>
> > frames via tee-supplicant in user space. A fallback mechanism is kept to
> > route RPMB frames via tee-supplicant if the RPMB subsystem isn't
> > available.
> >
> > The OP-TEE RPC ABI is extended to support iterating over all RPMB
> > devices until one is found with the expected RPMB key already
> > programmed.
> >
> > Signed-off-by: Jens Wiklander <[email protected]>
> > ---
> > drivers/tee/optee/core.c | 30 ++++
> > drivers/tee/optee/device.c | 7 +
> > drivers/tee/optee/ffa_abi.c | 8 +
> > drivers/tee/optee/optee_private.h | 21 ++-
> > drivers/tee/optee/optee_rpc_cmd.h | 35 +++++
> > drivers/tee/optee/rpc.c | 233 ++++++++++++++++++++++++++++++
> > drivers/tee/optee/smc_abi.c | 7 +
> > 7 files changed, 340 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
> > index 3aed554bc8d8..082691c10a90 100644
> > --- a/drivers/tee/optee/core.c
> > +++ b/drivers/tee/optee/core.c
> > @@ -11,6 +11,7 @@
> > #include <linux/io.h>
> > #include <linux/mm.h>
> > #include <linux/module.h>
> > +#include <linux/rpmb.h>
> > #include <linux/slab.h>
> > #include <linux/string.h>
> > #include <linux/tee_drv.h>
> > @@ -80,6 +81,31 @@ void optee_pool_op_free_helper(struct tee_shm_pool *pool, struct tee_shm *shm,
> > shm->pages = NULL;
> > }
> >
> > +void optee_bus_scan_rpmb(struct work_struct *work)
> > +{
> > + struct optee *optee = container_of(work, struct optee,
> > + rpmb_scan_bus_work);
> > + int ret;
> > +
> > + if (!optee->rpmb_scan_bus_done) {
> > + ret = optee_enumerate_devices(PTA_CMD_GET_DEVICES_RPMB);
> > + optee->rpmb_scan_bus_done = !ret;
> > + if (ret && ret != -ENODEV)
> > + pr_info("Scanning for RPMB device: ret %d\n", ret);
> > + }
> > +}
> > +
> > +int optee_rpmb_intf_rdev(struct notifier_block *intf, unsigned long action,
> > + void *data)
> > +{
> > + struct optee *optee = container_of(intf, struct optee, rpmb_intf);
> > +
> > + if (action == RPMB_NOTIFY_ADD_DEVICE)
> > + schedule_work(&optee->rpmb_scan_bus_work);
> > +
> > + return 0;
> > +}
> > +
> > static void optee_bus_scan(struct work_struct *work)
> > {
> > WARN_ON(optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP));
> > @@ -161,6 +187,8 @@ void optee_release_supp(struct tee_context *ctx)
> >
> > void optee_remove_common(struct optee *optee)
> > {
> > + rpmb_interface_unregister(&optee->rpmb_intf);
> > + cancel_work_sync(&optee->rpmb_scan_bus_work);
> > /* Unregister OP-TEE specific client devices on TEE bus */
> > optee_unregister_devices();
> >
> > @@ -177,6 +205,8 @@ void optee_remove_common(struct optee *optee)
> > tee_shm_pool_free(optee->pool);
> > optee_supp_uninit(&optee->supp);
> > mutex_destroy(&optee->call_queue.mutex);
> > + rpmb_dev_put(optee->rpmb_dev);
> > + mutex_destroy(&optee->rpmb_dev_mutex);
> > }
> >
> > static int smc_abi_rc;
> > diff --git a/drivers/tee/optee/device.c b/drivers/tee/optee/device.c
> > index 4b1092127694..4274876857c8 100644
> > --- a/drivers/tee/optee/device.c
> > +++ b/drivers/tee/optee/device.c
> > @@ -43,6 +43,13 @@ static int get_devices(struct tee_context *ctx, u32 session,
> > ret = tee_client_invoke_func(ctx, &inv_arg, param);
> > if ((ret < 0) || ((inv_arg.ret != TEEC_SUCCESS) &&
> > (inv_arg.ret != TEEC_ERROR_SHORT_BUFFER))) {
> > + /*
> > + * TEE_ERROR_STORAGE_NOT_AVAILABLE is returned when getting
> > + * the list of device TAs that depends on RPMB but a usable
> > + * RPMB device isn't found.
> > + */
> > + if (inv_arg.ret == TEE_ERROR_STORAGE_NOT_AVAILABLE)
> > + return -ENODEV;
> > pr_err("PTA_CMD_GET_DEVICES invoke function err: %x\n",
> > inv_arg.ret);
> > return -EINVAL;
> > diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c
> > index ecb5eb079408..a8dfdb30b4e8 100644
> > --- a/drivers/tee/optee/ffa_abi.c
> > +++ b/drivers/tee/optee/ffa_abi.c
> > @@ -7,6 +7,7 @@
> >
> > #include <linux/arm_ffa.h>
> > #include <linux/errno.h>
> > +#include <linux/rpmb.h>
> > #include <linux/scatterlist.h>
> > #include <linux/sched.h>
> > #include <linux/slab.h>
> > @@ -934,6 +935,7 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
> > optee_cq_init(&optee->call_queue, 0);
> > optee_supp_init(&optee->supp);
> > optee_shm_arg_cache_init(optee, arg_cache_flags);
> > + mutex_init(&optee->rpmb_dev_mutex);
> > ffa_dev_set_drvdata(ffa_dev, optee);
> > ctx = teedev_open(optee->teedev);
> > if (IS_ERR(ctx)) {
> > @@ -955,6 +957,9 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
> > if (rc)
> > goto err_unregister_devices;
> >
> > + INIT_WORK(&optee->rpmb_scan_bus_work, optee_bus_scan_rpmb);
> > + optee->rpmb_intf.notifier_call = optee_rpmb_intf_rdev;
> > + rpmb_interface_register(&optee->rpmb_intf);
> > pr_info("initialized driver\n");
> > return 0;
> >
> > @@ -968,6 +973,9 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
> > teedev_close_context(ctx);
> > err_rhashtable_free:
> > rhashtable_free_and_destroy(&optee->ffa.global_ids, rh_free_fn, NULL);
> > + rpmb_dev_put(optee->rpmb_dev);
> > + mutex_destroy(&optee->rpmb_dev_mutex);
> > + rpmb_interface_unregister(&optee->rpmb_intf);
> > optee_supp_uninit(&optee->supp);
> > mutex_destroy(&optee->call_queue.mutex);
> > mutex_destroy(&optee->ffa.mutex);
> > diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
> > index 7a5243c78b55..ae72f3dda1d2 100644
> > --- a/drivers/tee/optee/optee_private.h
> > +++ b/drivers/tee/optee/optee_private.h
> > @@ -8,6 +8,7 @@
> >
> > #include <linux/arm-smccc.h>
> > #include <linux/rhashtable.h>
> > +#include <linux/rpmb.h>
> > #include <linux/semaphore.h>
> > #include <linux/tee_drv.h>
> > #include <linux/types.h>
> > @@ -20,11 +21,13 @@
> > /* Some Global Platform error codes used in this driver */
> > #define TEEC_SUCCESS 0x00000000
> > #define TEEC_ERROR_BAD_PARAMETERS 0xFFFF0006
> > +#define TEEC_ERROR_ITEM_NOT_FOUND 0xFFFF0008
> > #define TEEC_ERROR_NOT_SUPPORTED 0xFFFF000A
> > #define TEEC_ERROR_COMMUNICATION 0xFFFF000E
> > #define TEEC_ERROR_OUT_OF_MEMORY 0xFFFF000C
> > #define TEEC_ERROR_BUSY 0xFFFF000D
> > #define TEEC_ERROR_SHORT_BUFFER 0xFFFF0010
> > +#define TEE_ERROR_STORAGE_NOT_AVAILABLE 0xF0100003
> >
> > #define TEEC_ORIGIN_COMMS 0x00000002
> >
> > @@ -197,6 +200,12 @@ struct optee_ops {
> > * @notif: notification synchronization struct
> > * @supp: supplicant synchronization struct for RPC to supplicant
> > * @pool: shared memory pool
> > + * @mutex: mutex protecting @rpmb_dev
> > + * @rpmb_dev: current RPMB device or NULL
> > + * @rpmb_scan_bus_done flag if device registation of RPMB dependent devices
> > + * was already done
> > + * @rpmb_scan_bus_work workq to for an RPMB device and to scan optee bus
> > + * and register RPMB dependent optee drivers
> > * @rpc_param_count: If > 0 number of RPC parameters to make room for
> > * @scan_bus_done flag if device registation was already done.
> > * @scan_bus_work workq to scan optee bus and register optee drivers
> > @@ -215,9 +224,15 @@ struct optee {
> > struct optee_notif notif;
> > struct optee_supp supp;
> > struct tee_shm_pool *pool;
> > + /* Protects rpmb_dev pointer */
> > + struct mutex rpmb_dev_mutex;
> > + struct rpmb_dev *rpmb_dev;
> > + struct notifier_block rpmb_intf;
> > unsigned int rpc_param_count;
> > - bool scan_bus_done;
> > + bool scan_bus_done;
> > + bool rpmb_scan_bus_done;
> > struct work_struct scan_bus_work;
> > + struct work_struct rpmb_scan_bus_work;
> > };
> >
> > struct optee_session {
> > @@ -280,8 +295,12 @@ int optee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session);
> >
> > #define PTA_CMD_GET_DEVICES 0x0
> > #define PTA_CMD_GET_DEVICES_SUPP 0x1
> > +#define PTA_CMD_GET_DEVICES_RPMB 0x2
> > int optee_enumerate_devices(u32 func);
> > void optee_unregister_devices(void);
> > +void optee_bus_scan_rpmb(struct work_struct *work);
> > +int optee_rpmb_intf_rdev(struct notifier_block *intf, unsigned long action,
> > + void *data);
> >
> > int optee_pool_op_alloc_helper(struct tee_shm_pool *pool, struct tee_shm *shm,
> > size_t size, size_t align,
> > diff --git a/drivers/tee/optee/optee_rpc_cmd.h b/drivers/tee/optee/optee_rpc_cmd.h
> > index f3f06e0994a7..f351a8ac69fc 100644
> > --- a/drivers/tee/optee/optee_rpc_cmd.h
> > +++ b/drivers/tee/optee/optee_rpc_cmd.h
> > @@ -16,6 +16,14 @@
> > * and sends responses.
> > */
> >
> > +/*
> > + * Replay Protected Memory Block access
> > + *
> > + * [in] memref[0] Frames to device
> > + * [out] memref[1] Frames from device
> > + */
> > +#define OPTEE_RPC_CMD_RPMB 1
> > +
> > /*
> > * Get time
> > *
> > @@ -103,4 +111,31 @@
> > /* I2C master control flags */
> > #define OPTEE_RPC_I2C_FLAGS_TEN_BIT BIT(0)
> >
> > +/*
> > + * Reset RPMB probing
> > + *
> > + * Releases an eventually already used RPMB devices and starts over searching
> > + * for RPMB devices. Returns the kind of shared memory to use in subsequent
> > + * OPTEE_RPC_CMD_RPMB_PROBE_NEXT and OPTEE_RPC_CMD_RPMB calls.
> > + *
> > + * [out] value[0].a OPTEE_RPC_SHM_TYPE_*, the parameter for
> > + * OPTEE_RPC_CMD_SHM_ALLOC
> > + */
> > +#define OPTEE_RPC_CMD_RPMB_PROBE_RESET 22
> > +
>
> AFAICS from [1], this RPMB reset probing is only used to check if the
> kernel supports RPMB probing or not. I suppose that should be detected
> via a single RPC call like: OPTEE_RPC_CMD_RPMB_PROBE. Other than that
> the shared memory allocation type can be used as
> THREAD_SHM_TYPE_KERNEL_PRIVATE if OPTEE_RPC_CMD_RPMB_PROBE works
> otherwise THREAD_SHM_TYPE_APPLICATION can be used for legacy RPMB init
> via tee-supplicant.
>
> Is there any other specific scenario I am missing which requires an
> explicit RPMB probe reset call?

That assumes that we're not going to implement
OPTEE_RPC_CMD_RPMB_PROBE_RESET and OPTEE_RPC_CMD_RPMB_PROBE_NEXT in
the tee-supplicant. We should implement those RPCs in the
tee-supplicant too since it solves the problem with finding the RPMB
device without device-specific runtime arguments for the
tee-supplicant.

I'd also like to keep the ABI flexible so we for instance can handle a
removable RPMB from the secure world.

Cheers,
Jens

>
> [1] https://github.com/jenswi-linaro/optee_os/commit/50ed7324411e3bdf7dba702d75eb0dbedda1c5cd
>
> -Sumit
>
> > +/*
> > + * Probe next RPMB device
> > + *
> > + * [out] value[0].a Type of RPMB device, OPTEE_RPC_RPMB_*
> > + * [out] value[0].b EXT CSD-slice 168 "RPMB Size"
> > + * [out] value[0].c EXT CSD-slice 222 "Reliable Write Sector Count"
> > + * [out] memref[1] Buffer with the raw CID
> > + */
> > +#define OPTEE_RPC_CMD_RPMB_PROBE_NEXT 23
> > +
> > +/* Type of RPMB device */
> > +#define OPTEE_RPC_RPMB_EMMC 0
> > +#define OPTEE_RPC_RPMB_UFS 1
> > +#define OPTEE_RPC_RPMB_NVME 2
> > +
> > #endif /*__OPTEE_RPC_CMD_H*/
> > diff --git a/drivers/tee/optee/rpc.c b/drivers/tee/optee/rpc.c
> > index e69bc6380683..e211c1c94984 100644
> > --- a/drivers/tee/optee/rpc.c
> > +++ b/drivers/tee/optee/rpc.c
> > @@ -7,6 +7,7 @@
> >
> > #include <linux/delay.h>
> > #include <linux/i2c.h>
> > +#include <linux/rpmb.h>
> > #include <linux/slab.h>
> > #include <linux/tee_drv.h>
> > #include "optee_private.h"
> > @@ -255,6 +256,229 @@ void optee_rpc_cmd_free_suppl(struct tee_context *ctx, struct tee_shm *shm)
> > optee_supp_thrd_req(ctx, OPTEE_RPC_CMD_SHM_FREE, 1, &param);
> > }
> >
> > +static void handle_rpc_func_rpmb_probe_reset(struct tee_context *ctx,
> > + struct optee *optee,
> > + struct optee_msg_arg *arg)
> > +{
> > + struct tee_param params[1];
> > +
> > + if (!IS_ENABLED(CONFIG_RPMB)) {
> > + handle_rpc_supp_cmd(ctx, optee, arg);
> > + return;
> > + }
> > +
> > + if (arg->num_params != ARRAY_SIZE(params) ||
> > + optee->ops->from_msg_param(optee, params, arg->num_params,
> > + arg->params) ||
> > + params[0].attr != TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT) {
> > + arg->ret = TEEC_ERROR_BAD_PARAMETERS;
> > + return;
> > + }
> > +
> > + params[0].u.value.a = OPTEE_RPC_SHM_TYPE_KERNEL;
> > + params[0].u.value.b = 0;
> > + params[0].u.value.c = 0;
> > + if (optee->ops->to_msg_param(optee, arg->params,
> > + arg->num_params, params)) {
> > + arg->ret = TEEC_ERROR_BAD_PARAMETERS;
> > + return;
> > + }
> > +
> > + mutex_lock(&optee->rpmb_dev_mutex);
> > + rpmb_dev_put(optee->rpmb_dev);
> > + optee->rpmb_dev = NULL;
> > + mutex_unlock(&optee->rpmb_dev_mutex);
> > +
> > + arg->ret = TEEC_SUCCESS;
> > +}
> > +
> > +static int rpmb_type_to_rpc_type(enum rpmb_type rtype)
> > +{
> > + switch (rtype) {
> > + case RPMB_TYPE_EMMC:
> > + return OPTEE_RPC_RPMB_EMMC;
> > + case RPMB_TYPE_UFS:
> > + return OPTEE_RPC_RPMB_UFS;
> > + case RPMB_TYPE_NVME:
> > + return OPTEE_RPC_RPMB_NVME;
> > + default:
> > + return -1;
> > + }
> > +}
> > +
> > +static int rpc_rpmb_match(struct rpmb_dev *rdev, const void *data)
> > +{
> > + return rpmb_type_to_rpc_type(rdev->descr.type) >= 0;
> > +}
> > +
> > +static void handle_rpc_func_rpmb_probe_next(struct tee_context *ctx,
> > + struct optee *optee,
> > + struct optee_msg_arg *arg)
> > +{
> > + struct rpmb_dev *rdev;
> > + struct tee_param params[2];
> > + void *buf;
> > +
> > + if (!IS_REACHABLE(CONFIG_RPMB)) {
> > + handle_rpc_supp_cmd(ctx, optee, arg);
> > + return;
> > + }
> > +
> > + if (arg->num_params != ARRAY_SIZE(params) ||
> > + optee->ops->from_msg_param(optee, params, arg->num_params,
> > + arg->params) ||
> > + params[0].attr != TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT ||
> > + params[1].attr != TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT) {
> > + arg->ret = TEEC_ERROR_BAD_PARAMETERS;
> > + return;
> > + }
> > + buf = tee_shm_get_va(params[1].u.memref.shm,
> > + params[1].u.memref.shm_offs);
> > + if (!buf) {
> > + arg->ret = TEEC_ERROR_BAD_PARAMETERS;
> > + return;
> > + }
> > +
> > + mutex_lock(&optee->rpmb_dev_mutex);
> > + rdev = rpmb_dev_find_device(NULL, optee->rpmb_dev, rpc_rpmb_match);
> > + rpmb_dev_put(optee->rpmb_dev);
> > + optee->rpmb_dev = rdev;
> > + mutex_unlock(&optee->rpmb_dev_mutex);
> > +
> > + if (!rdev) {
> > + arg->ret = TEEC_ERROR_ITEM_NOT_FOUND;
> > + return;
> > + }
> > +
> > + if (params[1].u.memref.size < rdev->descr.dev_id_len) {
> > + arg->ret = TEEC_ERROR_SHORT_BUFFER;
> > + return;
> > + }
> > + memcpy(buf, rdev->descr.dev_id, rdev->descr.dev_id_len);
> > + params[1].u.memref.size = rdev->descr.dev_id_len;
> > + params[0].u.value.a = rpmb_type_to_rpc_type(rdev->descr.type);
> > + params[0].u.value.b = rdev->descr.capacity;
> > + params[0].u.value.c = rdev->descr.reliable_wr_count;
> > + if (optee->ops->to_msg_param(optee, arg->params,
> > + arg->num_params, params)) {
> > + arg->ret = TEEC_ERROR_BAD_PARAMETERS;
> > + return;
> > + }
> > +
> > + arg->ret = TEEC_SUCCESS;
> > +}
> > +
> > +/* Request */
> > +struct rpmb_req {
> > + u16 cmd;
> > +#define RPMB_CMD_DATA_REQ 0x00
> > +#define RPMB_CMD_GET_DEV_INFO 0x01
> > + u16 dev_id;
> > + u16 block_count;
> > + /* Optional data frames (rpmb_data_frame) follow */
> > +};
> > +
> > +#define RPMB_REQ_DATA(req) ((void *)((struct rpmb_req *)(req) + 1))
> > +
> > +#define RPMB_CID_SZ 16
> > +
> > +/* Response to device info request */
> > +struct rpmb_dev_info {
> > + u8 cid[RPMB_CID_SZ];
> > + u8 rpmb_size_mult; /* EXT CSD-slice 168: RPMB Size */
> > + u8 rel_wr_sec_c; /* EXT CSD-slice 222: Reliable Write Sector */
> > + /* Count */
> > + u8 ret_code;
> > +#define RPMB_CMD_GET_DEV_INFO_RET_OK 0x00
> > +#define RPMB_CMD_GET_DEV_INFO_RET_ERROR 0x01
> > +};
> > +
> > +static int get_dev_info(struct rpmb_dev *rdev, void *rsp, size_t rsp_size)
> > +{
> > + struct rpmb_dev_info *dev_info;
> > +
> > + if (rsp_size != sizeof(*dev_info))
> > + return TEEC_ERROR_BAD_PARAMETERS;
> > +
> > + dev_info = rsp;
> > + memcpy(dev_info->cid, rdev->descr.dev_id, sizeof(dev_info->cid));
> > + dev_info->rpmb_size_mult = rdev->descr.capacity;
> > + dev_info->rel_wr_sec_c = rdev->descr.reliable_wr_count;
> > + dev_info->ret_code = RPMB_CMD_GET_DEV_INFO_RET_OK;
> > +
> > + return TEEC_SUCCESS;
> > +}
> > +
> > +/*
> > + * req is one struct rpmb_req followed by one or more struct rpmb_data_frame
> > + * rsp is either one struct rpmb_dev_info or one or more struct rpmb_data_frame
> > + */
> > +static u32 rpmb_process_request(struct optee *optee, struct rpmb_dev *rdev,
> > + void *req, size_t req_size,
> > + void *rsp, size_t rsp_size)
> > +{
> > + struct rpmb_req *sreq = req;
> > + int rc;
> > +
> > + if (req_size < sizeof(*sreq))
> > + return TEEC_ERROR_BAD_PARAMETERS;
> > +
> > + switch (sreq->cmd) {
> > + case RPMB_CMD_DATA_REQ:
> > + rc = rpmb_route_frames(rdev, RPMB_REQ_DATA(req),
> > + req_size - sizeof(struct rpmb_req),
> > + rsp, rsp_size);
> > + if (rc)
> > + return TEEC_ERROR_BAD_PARAMETERS;
> > + return TEEC_SUCCESS;
> > + case RPMB_CMD_GET_DEV_INFO:
> > + return get_dev_info(rdev, rsp, rsp_size);
> > + default:
> > + return TEEC_ERROR_BAD_PARAMETERS;
> > + }
> > +}
> > +
> > +static void handle_rpc_func_rpmb(struct tee_context *ctx, struct optee *optee,
> > + struct optee_msg_arg *arg)
> > +{
> > + struct tee_param params[2];
> > + struct rpmb_dev *rdev;
> > + void *p0, *p1;
> > +
> > + mutex_lock(&optee->rpmb_dev_mutex);
> > + rdev = rpmb_dev_get(optee->rpmb_dev);
> > + mutex_unlock(&optee->rpmb_dev_mutex);
> > + if (!rdev) {
> > + handle_rpc_supp_cmd(ctx, optee, arg);
> > + return;
> > + }
> > +
> > + if (arg->num_params != ARRAY_SIZE(params) ||
> > + optee->ops->from_msg_param(optee, params, arg->num_params,
> > + arg->params) ||
> > + params[0].attr != TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT ||
> > + params[1].attr != TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT) {
> > + arg->ret = TEEC_ERROR_BAD_PARAMETERS;
> > + goto out;
> > + }
> > +
> > + p0 = tee_shm_get_va(params[0].u.memref.shm,
> > + params[0].u.memref.shm_offs);
> > + p1 = tee_shm_get_va(params[1].u.memref.shm,
> > + params[1].u.memref.shm_offs);
> > + arg->ret = rpmb_process_request(optee, rdev, p0,
> > + params[0].u.memref.size,
> > + p1, params[1].u.memref.size);
> > + if (arg->ret)
> > + goto out;
> > +
> > + if (optee->ops->to_msg_param(optee, arg->params,
> > + arg->num_params, params))
> > + arg->ret = TEEC_ERROR_BAD_PARAMETERS;
> > +out:
> > + rpmb_dev_put(rdev);
> > +}
> > +
> > void optee_rpc_cmd(struct tee_context *ctx, struct optee *optee,
> > struct optee_msg_arg *arg)
> > {
> > @@ -271,6 +495,15 @@ void optee_rpc_cmd(struct tee_context *ctx, struct optee *optee,
> > case OPTEE_RPC_CMD_I2C_TRANSFER:
> > handle_rpc_func_cmd_i2c_transfer(ctx, arg);
> > break;
> > + case OPTEE_RPC_CMD_RPMB_PROBE_RESET:
> > + handle_rpc_func_rpmb_probe_reset(ctx, optee, arg);
> > + break;
> > + case OPTEE_RPC_CMD_RPMB_PROBE_NEXT:
> > + handle_rpc_func_rpmb_probe_next(ctx, optee, arg);
> > + break;
> > + case OPTEE_RPC_CMD_RPMB:
> > + handle_rpc_func_rpmb(ctx, optee, arg);
> > + break;
> > default:
> > handle_rpc_supp_cmd(ctx, optee, arg);
> > }
> > diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c
> > index a37f87087e5c..c23bcf35c8cb 100644
> > --- a/drivers/tee/optee/smc_abi.c
> > +++ b/drivers/tee/optee/smc_abi.c
> > @@ -20,6 +20,7 @@
> > #include <linux/of_irq.h>
> > #include <linux/of_platform.h>
> > #include <linux/platform_device.h>
> > +#include <linux/rpmb.h>
> > #include <linux/sched.h>
> > #include <linux/slab.h>
> > #include <linux/string.h>
> > @@ -1715,6 +1716,7 @@ static int optee_probe(struct platform_device *pdev)
> > optee->smc.memremaped_shm = memremaped_shm;
> > optee->pool = pool;
> > optee_shm_arg_cache_init(optee, arg_cache_flags);
> > + mutex_init(&optee->rpmb_dev_mutex);
> >
> > platform_set_drvdata(pdev, optee);
> > ctx = teedev_open(optee->teedev);
> > @@ -1769,6 +1771,9 @@ static int optee_probe(struct platform_device *pdev)
> > if (rc)
> > goto err_disable_shm_cache;
> >
> > + INIT_WORK(&optee->rpmb_scan_bus_work, optee_bus_scan_rpmb);
> > + optee->rpmb_intf.notifier_call = optee_rpmb_intf_rdev;
> > + rpmb_interface_register(&optee->rpmb_intf);
> > pr_info("initialized driver\n");
> > return 0;
> >
> > @@ -1782,6 +1787,8 @@ static int optee_probe(struct platform_device *pdev)
> > err_close_ctx:
> > teedev_close_context(ctx);
> > err_supp_uninit:
> > + rpmb_dev_put(optee->rpmb_dev);
> > + mutex_destroy(&optee->rpmb_dev_mutex);
> > optee_shm_arg_cache_uninit(optee);
> > optee_supp_uninit(&optee->supp);
> > mutex_destroy(&optee->call_queue.mutex);
> > --
> > 2.34.1
> >

2024-04-12 07:08:00

by Sumit Garg

[permalink] [raw]
Subject: Re: [PATCH v4 3/3] optee: probe RPMB device using RPMB subsystem

On Thu, 11 Apr 2024 at 12:23, Jens Wiklander <[email protected]> wrote:
>
> Hi Sumit,
>
> On Wed, Apr 10, 2024 at 12:48 PM Sumit Garg <[email protected]> wrote:
> >
> > Hi Jens,
> >
> > On Fri, 5 Apr 2024 at 17:23, Jens Wiklander <[email protected]> wrote:
> > >
> > > Adds support in the OP-TEE drivers (both SMC and FF-A ABIs) to probe and
> > > use an RPMB device via the RPBM subsystem instead of passing the RPMB
> >
> > s/RPBM/RPMB/
>
> Thanks, I'll fix it.
>
> >
> > > frames via tee-supplicant in user space. A fallback mechanism is kept to
> > > route RPMB frames via tee-supplicant if the RPMB subsystem isn't
> > > available.
> > >
> > > The OP-TEE RPC ABI is extended to support iterating over all RPMB
> > > devices until one is found with the expected RPMB key already
> > > programmed.
> > >
> > > Signed-off-by: Jens Wiklander <[email protected]>
> > > ---
> > > drivers/tee/optee/core.c | 30 ++++
> > > drivers/tee/optee/device.c | 7 +
> > > drivers/tee/optee/ffa_abi.c | 8 +
> > > drivers/tee/optee/optee_private.h | 21 ++-
> > > drivers/tee/optee/optee_rpc_cmd.h | 35 +++++
> > > drivers/tee/optee/rpc.c | 233 ++++++++++++++++++++++++++++++
> > > drivers/tee/optee/smc_abi.c | 7 +
> > > 7 files changed, 340 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
> > > index 3aed554bc8d8..082691c10a90 100644
> > > --- a/drivers/tee/optee/core.c
> > > +++ b/drivers/tee/optee/core.c
> > > @@ -11,6 +11,7 @@
> > > #include <linux/io.h>
> > > #include <linux/mm.h>
> > > #include <linux/module.h>
> > > +#include <linux/rpmb.h>
> > > #include <linux/slab.h>
> > > #include <linux/string.h>
> > > #include <linux/tee_drv.h>
> > > @@ -80,6 +81,31 @@ void optee_pool_op_free_helper(struct tee_shm_pool *pool, struct tee_shm *shm,
> > > shm->pages = NULL;
> > > }
> > >
> > > +void optee_bus_scan_rpmb(struct work_struct *work)
> > > +{
> > > + struct optee *optee = container_of(work, struct optee,
> > > + rpmb_scan_bus_work);
> > > + int ret;
> > > +
> > > + if (!optee->rpmb_scan_bus_done) {
> > > + ret = optee_enumerate_devices(PTA_CMD_GET_DEVICES_RPMB);
> > > + optee->rpmb_scan_bus_done = !ret;
> > > + if (ret && ret != -ENODEV)
> > > + pr_info("Scanning for RPMB device: ret %d\n", ret);
> > > + }
> > > +}
> > > +
> > > +int optee_rpmb_intf_rdev(struct notifier_block *intf, unsigned long action,
> > > + void *data)
> > > +{
> > > + struct optee *optee = container_of(intf, struct optee, rpmb_intf);
> > > +
> > > + if (action == RPMB_NOTIFY_ADD_DEVICE)
> > > + schedule_work(&optee->rpmb_scan_bus_work);
> > > +
> > > + return 0;
> > > +}
> > > +
> > > static void optee_bus_scan(struct work_struct *work)
> > > {
> > > WARN_ON(optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP));
> > > @@ -161,6 +187,8 @@ void optee_release_supp(struct tee_context *ctx)
> > >
> > > void optee_remove_common(struct optee *optee)
> > > {
> > > + rpmb_interface_unregister(&optee->rpmb_intf);
> > > + cancel_work_sync(&optee->rpmb_scan_bus_work);
> > > /* Unregister OP-TEE specific client devices on TEE bus */
> > > optee_unregister_devices();
> > >
> > > @@ -177,6 +205,8 @@ void optee_remove_common(struct optee *optee)
> > > tee_shm_pool_free(optee->pool);
> > > optee_supp_uninit(&optee->supp);
> > > mutex_destroy(&optee->call_queue.mutex);
> > > + rpmb_dev_put(optee->rpmb_dev);
> > > + mutex_destroy(&optee->rpmb_dev_mutex);
> > > }
> > >
> > > static int smc_abi_rc;
> > > diff --git a/drivers/tee/optee/device.c b/drivers/tee/optee/device.c
> > > index 4b1092127694..4274876857c8 100644
> > > --- a/drivers/tee/optee/device.c
> > > +++ b/drivers/tee/optee/device.c
> > > @@ -43,6 +43,13 @@ static int get_devices(struct tee_context *ctx, u32 session,
> > > ret = tee_client_invoke_func(ctx, &inv_arg, param);
> > > if ((ret < 0) || ((inv_arg.ret != TEEC_SUCCESS) &&
> > > (inv_arg.ret != TEEC_ERROR_SHORT_BUFFER))) {
> > > + /*
> > > + * TEE_ERROR_STORAGE_NOT_AVAILABLE is returned when getting
> > > + * the list of device TAs that depends on RPMB but a usable
> > > + * RPMB device isn't found.
> > > + */
> > > + if (inv_arg.ret == TEE_ERROR_STORAGE_NOT_AVAILABLE)
> > > + return -ENODEV;
> > > pr_err("PTA_CMD_GET_DEVICES invoke function err: %x\n",
> > > inv_arg.ret);
> > > return -EINVAL;
> > > diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c
> > > index ecb5eb079408..a8dfdb30b4e8 100644
> > > --- a/drivers/tee/optee/ffa_abi.c
> > > +++ b/drivers/tee/optee/ffa_abi.c
> > > @@ -7,6 +7,7 @@
> > >
> > > #include <linux/arm_ffa.h>
> > > #include <linux/errno.h>
> > > +#include <linux/rpmb.h>
> > > #include <linux/scatterlist.h>
> > > #include <linux/sched.h>
> > > #include <linux/slab.h>
> > > @@ -934,6 +935,7 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
> > > optee_cq_init(&optee->call_queue, 0);
> > > optee_supp_init(&optee->supp);
> > > optee_shm_arg_cache_init(optee, arg_cache_flags);
> > > + mutex_init(&optee->rpmb_dev_mutex);
> > > ffa_dev_set_drvdata(ffa_dev, optee);
> > > ctx = teedev_open(optee->teedev);
> > > if (IS_ERR(ctx)) {
> > > @@ -955,6 +957,9 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
> > > if (rc)
> > > goto err_unregister_devices;
> > >
> > > + INIT_WORK(&optee->rpmb_scan_bus_work, optee_bus_scan_rpmb);
> > > + optee->rpmb_intf.notifier_call = optee_rpmb_intf_rdev;
> > > + rpmb_interface_register(&optee->rpmb_intf);
> > > pr_info("initialized driver\n");
> > > return 0;
> > >
> > > @@ -968,6 +973,9 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
> > > teedev_close_context(ctx);
> > > err_rhashtable_free:
> > > rhashtable_free_and_destroy(&optee->ffa.global_ids, rh_free_fn, NULL);
> > > + rpmb_dev_put(optee->rpmb_dev);
> > > + mutex_destroy(&optee->rpmb_dev_mutex);
> > > + rpmb_interface_unregister(&optee->rpmb_intf);
> > > optee_supp_uninit(&optee->supp);
> > > mutex_destroy(&optee->call_queue.mutex);
> > > mutex_destroy(&optee->ffa.mutex);
> > > diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
> > > index 7a5243c78b55..ae72f3dda1d2 100644
> > > --- a/drivers/tee/optee/optee_private.h
> > > +++ b/drivers/tee/optee/optee_private.h
> > > @@ -8,6 +8,7 @@
> > >
> > > #include <linux/arm-smccc.h>
> > > #include <linux/rhashtable.h>
> > > +#include <linux/rpmb.h>
> > > #include <linux/semaphore.h>
> > > #include <linux/tee_drv.h>
> > > #include <linux/types.h>
> > > @@ -20,11 +21,13 @@
> > > /* Some Global Platform error codes used in this driver */
> > > #define TEEC_SUCCESS 0x00000000
> > > #define TEEC_ERROR_BAD_PARAMETERS 0xFFFF0006
> > > +#define TEEC_ERROR_ITEM_NOT_FOUND 0xFFFF0008
> > > #define TEEC_ERROR_NOT_SUPPORTED 0xFFFF000A
> > > #define TEEC_ERROR_COMMUNICATION 0xFFFF000E
> > > #define TEEC_ERROR_OUT_OF_MEMORY 0xFFFF000C
> > > #define TEEC_ERROR_BUSY 0xFFFF000D
> > > #define TEEC_ERROR_SHORT_BUFFER 0xFFFF0010
> > > +#define TEE_ERROR_STORAGE_NOT_AVAILABLE 0xF0100003
> > >
> > > #define TEEC_ORIGIN_COMMS 0x00000002
> > >
> > > @@ -197,6 +200,12 @@ struct optee_ops {
> > > * @notif: notification synchronization struct
> > > * @supp: supplicant synchronization struct for RPC to supplicant
> > > * @pool: shared memory pool
> > > + * @mutex: mutex protecting @rpmb_dev
> > > + * @rpmb_dev: current RPMB device or NULL
> > > + * @rpmb_scan_bus_done flag if device registation of RPMB dependent devices
> > > + * was already done
> > > + * @rpmb_scan_bus_work workq to for an RPMB device and to scan optee bus
> > > + * and register RPMB dependent optee drivers
> > > * @rpc_param_count: If > 0 number of RPC parameters to make room for
> > > * @scan_bus_done flag if device registation was already done.
> > > * @scan_bus_work workq to scan optee bus and register optee drivers
> > > @@ -215,9 +224,15 @@ struct optee {
> > > struct optee_notif notif;
> > > struct optee_supp supp;
> > > struct tee_shm_pool *pool;
> > > + /* Protects rpmb_dev pointer */
> > > + struct mutex rpmb_dev_mutex;
> > > + struct rpmb_dev *rpmb_dev;
> > > + struct notifier_block rpmb_intf;
> > > unsigned int rpc_param_count;
> > > - bool scan_bus_done;
> > > + bool scan_bus_done;
> > > + bool rpmb_scan_bus_done;
> > > struct work_struct scan_bus_work;
> > > + struct work_struct rpmb_scan_bus_work;
> > > };
> > >
> > > struct optee_session {
> > > @@ -280,8 +295,12 @@ int optee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session);
> > >
> > > #define PTA_CMD_GET_DEVICES 0x0
> > > #define PTA_CMD_GET_DEVICES_SUPP 0x1
> > > +#define PTA_CMD_GET_DEVICES_RPMB 0x2
> > > int optee_enumerate_devices(u32 func);
> > > void optee_unregister_devices(void);
> > > +void optee_bus_scan_rpmb(struct work_struct *work);
> > > +int optee_rpmb_intf_rdev(struct notifier_block *intf, unsigned long action,
> > > + void *data);
> > >
> > > int optee_pool_op_alloc_helper(struct tee_shm_pool *pool, struct tee_shm *shm,
> > > size_t size, size_t align,
> > > diff --git a/drivers/tee/optee/optee_rpc_cmd.h b/drivers/tee/optee/optee_rpc_cmd.h
> > > index f3f06e0994a7..f351a8ac69fc 100644
> > > --- a/drivers/tee/optee/optee_rpc_cmd.h
> > > +++ b/drivers/tee/optee/optee_rpc_cmd.h
> > > @@ -16,6 +16,14 @@
> > > * and sends responses.
> > > */
> > >
> > > +/*
> > > + * Replay Protected Memory Block access
> > > + *
> > > + * [in] memref[0] Frames to device
> > > + * [out] memref[1] Frames from device
> > > + */
> > > +#define OPTEE_RPC_CMD_RPMB 1
> > > +
> > > /*
> > > * Get time
> > > *
> > > @@ -103,4 +111,31 @@
> > > /* I2C master control flags */
> > > #define OPTEE_RPC_I2C_FLAGS_TEN_BIT BIT(0)
> > >
> > > +/*
> > > + * Reset RPMB probing
> > > + *
> > > + * Releases an eventually already used RPMB devices and starts over searching
> > > + * for RPMB devices. Returns the kind of shared memory to use in subsequent
> > > + * OPTEE_RPC_CMD_RPMB_PROBE_NEXT and OPTEE_RPC_CMD_RPMB calls.
> > > + *
> > > + * [out] value[0].a OPTEE_RPC_SHM_TYPE_*, the parameter for
> > > + * OPTEE_RPC_CMD_SHM_ALLOC
> > > + */
> > > +#define OPTEE_RPC_CMD_RPMB_PROBE_RESET 22
> > > +
> >
> > AFAICS from [1], this RPMB reset probing is only used to check if the
> > kernel supports RPMB probing or not. I suppose that should be detected
> > via a single RPC call like: OPTEE_RPC_CMD_RPMB_PROBE. Other than that
> > the shared memory allocation type can be used as
> > THREAD_SHM_TYPE_KERNEL_PRIVATE if OPTEE_RPC_CMD_RPMB_PROBE works
> > otherwise THREAD_SHM_TYPE_APPLICATION can be used for legacy RPMB init
> > via tee-supplicant.
> >
> > Is there any other specific scenario I am missing which requires an
> > explicit RPMB probe reset call?
>
> That assumes that we're not going to implement
> OPTEE_RPC_CMD_RPMB_PROBE_RESET and OPTEE_RPC_CMD_RPMB_PROBE_NEXT in
> the tee-supplicant. We should implement those RPCs in the
> tee-supplicant too since it solves the problem with finding the RPMB
> device without device-specific runtime arguments for the
> tee-supplicant.

IMO, we should try to deprecate the tee-supplicant accesses to
hardware RPMB. The tee-supplicant can be useful for RPMB emulation
scenarios where we shouldn't require the dynamic discovery of RPMB.

>
> I'd also like to keep the ABI flexible so we for instance can handle a
> removable RPMB from the secure world.

That's an interesting scenario but I am not sure if we really would
like to deal with the complications of removable RPMB like what we
should do if a TA is accessing RPMB during which it is hot plugged?

However, I am in favour of an ABI which is simple enough to maintain
and allow flexibility for extension like adding a new RPC when it's
really needed etc.

-Sumit

2024-04-22 08:51:36

by Jens Wiklander

[permalink] [raw]
Subject: Re: [PATCH v4 3/3] optee: probe RPMB device using RPMB subsystem

On Fri, Apr 12, 2024 at 9:06 AM Sumit Garg <[email protected]> wrote:
>
> On Thu, 11 Apr 2024 at 12:23, Jens Wiklander <[email protected]> wrote:
> >
> > Hi Sumit,
> >
> > On Wed, Apr 10, 2024 at 12:48 PM Sumit Garg <[email protected]> wrote:
> > >
> > > Hi Jens,
> > >
> > > On Fri, 5 Apr 2024 at 17:23, Jens Wiklander <[email protected]> wrote:
> > > >
> > > > Adds support in the OP-TEE drivers (both SMC and FF-A ABIs) to probe and
> > > > use an RPMB device via the RPBM subsystem instead of passing the RPMB
> > >
> > > s/RPBM/RPMB/
> >
> > Thanks, I'll fix it.
> >
> > >
> > > > frames via tee-supplicant in user space. A fallback mechanism is kept to
> > > > route RPMB frames via tee-supplicant if the RPMB subsystem isn't
> > > > available.
> > > >
> > > > The OP-TEE RPC ABI is extended to support iterating over all RPMB
> > > > devices until one is found with the expected RPMB key already
> > > > programmed.
> > > >
> > > > Signed-off-by: Jens Wiklander <[email protected]>
> > > > ---
> > > > drivers/tee/optee/core.c | 30 ++++
> > > > drivers/tee/optee/device.c | 7 +
> > > > drivers/tee/optee/ffa_abi.c | 8 +
> > > > drivers/tee/optee/optee_private.h | 21 ++-
> > > > drivers/tee/optee/optee_rpc_cmd.h | 35 +++++
> > > > drivers/tee/optee/rpc.c | 233 ++++++++++++++++++++++++++++++
> > > > drivers/tee/optee/smc_abi.c | 7 +
> > > > 7 files changed, 340 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
> > > > index 3aed554bc8d8..082691c10a90 100644
> > > > --- a/drivers/tee/optee/core.c
> > > > +++ b/drivers/tee/optee/core.c
> > > > @@ -11,6 +11,7 @@
> > > > #include <linux/io.h>
> > > > #include <linux/mm.h>
> > > > #include <linux/module.h>
> > > > +#include <linux/rpmb.h>
> > > > #include <linux/slab.h>
> > > > #include <linux/string.h>
> > > > #include <linux/tee_drv.h>
> > > > @@ -80,6 +81,31 @@ void optee_pool_op_free_helper(struct tee_shm_pool *pool, struct tee_shm *shm,
> > > > shm->pages = NULL;
> > > > }
> > > >
> > > > +void optee_bus_scan_rpmb(struct work_struct *work)
> > > > +{
> > > > + struct optee *optee = container_of(work, struct optee,
> > > > + rpmb_scan_bus_work);
> > > > + int ret;
> > > > +
> > > > + if (!optee->rpmb_scan_bus_done) {
> > > > + ret = optee_enumerate_devices(PTA_CMD_GET_DEVICES_RPMB);
> > > > + optee->rpmb_scan_bus_done = !ret;
> > > > + if (ret && ret != -ENODEV)
> > > > + pr_info("Scanning for RPMB device: ret %d\n", ret);
> > > > + }
> > > > +}
> > > > +
> > > > +int optee_rpmb_intf_rdev(struct notifier_block *intf, unsigned long action,
> > > > + void *data)
> > > > +{
> > > > + struct optee *optee = container_of(intf, struct optee, rpmb_intf);
> > > > +
> > > > + if (action == RPMB_NOTIFY_ADD_DEVICE)
> > > > + schedule_work(&optee->rpmb_scan_bus_work);
> > > > +
> > > > + return 0;
> > > > +}
> > > > +
> > > > static void optee_bus_scan(struct work_struct *work)
> > > > {
> > > > WARN_ON(optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP));
> > > > @@ -161,6 +187,8 @@ void optee_release_supp(struct tee_context *ctx)
> > > >
> > > > void optee_remove_common(struct optee *optee)
> > > > {
> > > > + rpmb_interface_unregister(&optee->rpmb_intf);
> > > > + cancel_work_sync(&optee->rpmb_scan_bus_work);
> > > > /* Unregister OP-TEE specific client devices on TEE bus */
> > > > optee_unregister_devices();
> > > >
> > > > @@ -177,6 +205,8 @@ void optee_remove_common(struct optee *optee)
> > > > tee_shm_pool_free(optee->pool);
> > > > optee_supp_uninit(&optee->supp);
> > > > mutex_destroy(&optee->call_queue.mutex);
> > > > + rpmb_dev_put(optee->rpmb_dev);
> > > > + mutex_destroy(&optee->rpmb_dev_mutex);
> > > > }
> > > >
> > > > static int smc_abi_rc;
> > > > diff --git a/drivers/tee/optee/device.c b/drivers/tee/optee/device.c
> > > > index 4b1092127694..4274876857c8 100644
> > > > --- a/drivers/tee/optee/device.c
> > > > +++ b/drivers/tee/optee/device.c
> > > > @@ -43,6 +43,13 @@ static int get_devices(struct tee_context *ctx, u32 session,
> > > > ret = tee_client_invoke_func(ctx, &inv_arg, param);
> > > > if ((ret < 0) || ((inv_arg.ret != TEEC_SUCCESS) &&
> > > > (inv_arg.ret != TEEC_ERROR_SHORT_BUFFER))) {
> > > > + /*
> > > > + * TEE_ERROR_STORAGE_NOT_AVAILABLE is returned when getting
> > > > + * the list of device TAs that depends on RPMB but a usable
> > > > + * RPMB device isn't found.
> > > > + */
> > > > + if (inv_arg.ret == TEE_ERROR_STORAGE_NOT_AVAILABLE)
> > > > + return -ENODEV;
> > > > pr_err("PTA_CMD_GET_DEVICES invoke function err: %x\n",
> > > > inv_arg.ret);
> > > > return -EINVAL;
> > > > diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c
> > > > index ecb5eb079408..a8dfdb30b4e8 100644
> > > > --- a/drivers/tee/optee/ffa_abi.c
> > > > +++ b/drivers/tee/optee/ffa_abi.c
> > > > @@ -7,6 +7,7 @@
> > > >
> > > > #include <linux/arm_ffa.h>
> > > > #include <linux/errno.h>
> > > > +#include <linux/rpmb.h>
> > > > #include <linux/scatterlist.h>
> > > > #include <linux/sched.h>
> > > > #include <linux/slab.h>
> > > > @@ -934,6 +935,7 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
> > > > optee_cq_init(&optee->call_queue, 0);
> > > > optee_supp_init(&optee->supp);
> > > > optee_shm_arg_cache_init(optee, arg_cache_flags);
> > > > + mutex_init(&optee->rpmb_dev_mutex);
> > > > ffa_dev_set_drvdata(ffa_dev, optee);
> > > > ctx = teedev_open(optee->teedev);
> > > > if (IS_ERR(ctx)) {
> > > > @@ -955,6 +957,9 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
> > > > if (rc)
> > > > goto err_unregister_devices;
> > > >
> > > > + INIT_WORK(&optee->rpmb_scan_bus_work, optee_bus_scan_rpmb);
> > > > + optee->rpmb_intf.notifier_call = optee_rpmb_intf_rdev;
> > > > + rpmb_interface_register(&optee->rpmb_intf);
> > > > pr_info("initialized driver\n");
> > > > return 0;
> > > >
> > > > @@ -968,6 +973,9 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
> > > > teedev_close_context(ctx);
> > > > err_rhashtable_free:
> > > > rhashtable_free_and_destroy(&optee->ffa.global_ids, rh_free_fn, NULL);
> > > > + rpmb_dev_put(optee->rpmb_dev);
> > > > + mutex_destroy(&optee->rpmb_dev_mutex);
> > > > + rpmb_interface_unregister(&optee->rpmb_intf);
> > > > optee_supp_uninit(&optee->supp);
> > > > mutex_destroy(&optee->call_queue.mutex);
> > > > mutex_destroy(&optee->ffa.mutex);
> > > > diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
> > > > index 7a5243c78b55..ae72f3dda1d2 100644
> > > > --- a/drivers/tee/optee/optee_private.h
> > > > +++ b/drivers/tee/optee/optee_private.h
> > > > @@ -8,6 +8,7 @@
> > > >
> > > > #include <linux/arm-smccc.h>
> > > > #include <linux/rhashtable.h>
> > > > +#include <linux/rpmb.h>
> > > > #include <linux/semaphore.h>
> > > > #include <linux/tee_drv.h>
> > > > #include <linux/types.h>
> > > > @@ -20,11 +21,13 @@
> > > > /* Some Global Platform error codes used in this driver */
> > > > #define TEEC_SUCCESS 0x00000000
> > > > #define TEEC_ERROR_BAD_PARAMETERS 0xFFFF0006
> > > > +#define TEEC_ERROR_ITEM_NOT_FOUND 0xFFFF0008
> > > > #define TEEC_ERROR_NOT_SUPPORTED 0xFFFF000A
> > > > #define TEEC_ERROR_COMMUNICATION 0xFFFF000E
> > > > #define TEEC_ERROR_OUT_OF_MEMORY 0xFFFF000C
> > > > #define TEEC_ERROR_BUSY 0xFFFF000D
> > > > #define TEEC_ERROR_SHORT_BUFFER 0xFFFF0010
> > > > +#define TEE_ERROR_STORAGE_NOT_AVAILABLE 0xF0100003
> > > >
> > > > #define TEEC_ORIGIN_COMMS 0x00000002
> > > >
> > > > @@ -197,6 +200,12 @@ struct optee_ops {
> > > > * @notif: notification synchronization struct
> > > > * @supp: supplicant synchronization struct for RPC to supplicant
> > > > * @pool: shared memory pool
> > > > + * @mutex: mutex protecting @rpmb_dev
> > > > + * @rpmb_dev: current RPMB device or NULL
> > > > + * @rpmb_scan_bus_done flag if device registation of RPMB dependent devices
> > > > + * was already done
> > > > + * @rpmb_scan_bus_work workq to for an RPMB device and to scan optee bus
> > > > + * and register RPMB dependent optee drivers
> > > > * @rpc_param_count: If > 0 number of RPC parameters to make room for
> > > > * @scan_bus_done flag if device registation was already done.
> > > > * @scan_bus_work workq to scan optee bus and register optee drivers
> > > > @@ -215,9 +224,15 @@ struct optee {
> > > > struct optee_notif notif;
> > > > struct optee_supp supp;
> > > > struct tee_shm_pool *pool;
> > > > + /* Protects rpmb_dev pointer */
> > > > + struct mutex rpmb_dev_mutex;
> > > > + struct rpmb_dev *rpmb_dev;
> > > > + struct notifier_block rpmb_intf;
> > > > unsigned int rpc_param_count;
> > > > - bool scan_bus_done;
> > > > + bool scan_bus_done;
> > > > + bool rpmb_scan_bus_done;
> > > > struct work_struct scan_bus_work;
> > > > + struct work_struct rpmb_scan_bus_work;
> > > > };
> > > >
> > > > struct optee_session {
> > > > @@ -280,8 +295,12 @@ int optee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session);
> > > >
> > > > #define PTA_CMD_GET_DEVICES 0x0
> > > > #define PTA_CMD_GET_DEVICES_SUPP 0x1
> > > > +#define PTA_CMD_GET_DEVICES_RPMB 0x2
> > > > int optee_enumerate_devices(u32 func);
> > > > void optee_unregister_devices(void);
> > > > +void optee_bus_scan_rpmb(struct work_struct *work);
> > > > +int optee_rpmb_intf_rdev(struct notifier_block *intf, unsigned long action,
> > > > + void *data);
> > > >
> > > > int optee_pool_op_alloc_helper(struct tee_shm_pool *pool, struct tee_shm *shm,
> > > > size_t size, size_t align,
> > > > diff --git a/drivers/tee/optee/optee_rpc_cmd.h b/drivers/tee/optee/optee_rpc_cmd.h
> > > > index f3f06e0994a7..f351a8ac69fc 100644
> > > > --- a/drivers/tee/optee/optee_rpc_cmd.h
> > > > +++ b/drivers/tee/optee/optee_rpc_cmd.h
> > > > @@ -16,6 +16,14 @@
> > > > * and sends responses.
> > > > */
> > > >
> > > > +/*
> > > > + * Replay Protected Memory Block access
> > > > + *
> > > > + * [in] memref[0] Frames to device
> > > > + * [out] memref[1] Frames from device
> > > > + */
> > > > +#define OPTEE_RPC_CMD_RPMB 1
> > > > +
> > > > /*
> > > > * Get time
> > > > *
> > > > @@ -103,4 +111,31 @@
> > > > /* I2C master control flags */
> > > > #define OPTEE_RPC_I2C_FLAGS_TEN_BIT BIT(0)
> > > >
> > > > +/*
> > > > + * Reset RPMB probing
> > > > + *
> > > > + * Releases an eventually already used RPMB devices and starts over searching
> > > > + * for RPMB devices. Returns the kind of shared memory to use in subsequent
> > > > + * OPTEE_RPC_CMD_RPMB_PROBE_NEXT and OPTEE_RPC_CMD_RPMB calls.
> > > > + *
> > > > + * [out] value[0].a OPTEE_RPC_SHM_TYPE_*, the parameter for
> > > > + * OPTEE_RPC_CMD_SHM_ALLOC
> > > > + */
> > > > +#define OPTEE_RPC_CMD_RPMB_PROBE_RESET 22
> > > > +
> > >
> > > AFAICS from [1], this RPMB reset probing is only used to check if the
> > > kernel supports RPMB probing or not. I suppose that should be detected
> > > via a single RPC call like: OPTEE_RPC_CMD_RPMB_PROBE. Other than that
> > > the shared memory allocation type can be used as
> > > THREAD_SHM_TYPE_KERNEL_PRIVATE if OPTEE_RPC_CMD_RPMB_PROBE works
> > > otherwise THREAD_SHM_TYPE_APPLICATION can be used for legacy RPMB init
> > > via tee-supplicant.
> > >
> > > Is there any other specific scenario I am missing which requires an
> > > explicit RPMB probe reset call?
> >
> > That assumes that we're not going to implement
> > OPTEE_RPC_CMD_RPMB_PROBE_RESET and OPTEE_RPC_CMD_RPMB_PROBE_NEXT in
> > the tee-supplicant. We should implement those RPCs in the
> > tee-supplicant too since it solves the problem with finding the RPMB
> > device without device-specific runtime arguments for the
> > tee-supplicant.
>
> IMO, we should try to deprecate the tee-supplicant accesses to
> hardware RPMB. The tee-supplicant can be useful for RPMB emulation
> scenarios where we shouldn't require the dynamic discovery of RPMB.

There's no rush to do that, there's not too much maintenance. We can
discuss the next step once this is upstream.

>
> >
> > I'd also like to keep the ABI flexible so we for instance can handle a
> > removable RPMB from the secure world.
>
> That's an interesting scenario but I am not sure if we really would
> like to deal with the complications of removable RPMB like what we
> should do if a TA is accessing RPMB during which it is hot plugged?

We may need to panic the TA if the RPMB is unplugged at an unfavorable
moment. It's a special case, but it would be nice to resume RPMB
access once it's plugged in.

>
> However, I am in favour of an ABI which is simple enough to maintain
> and allow flexibility for extension like adding a new RPC when it's
> really needed etc.

Thanks,
Jens