2020-05-04 09:31:06

by Sudeep Holla

[permalink] [raw]
Subject: [PATCH v2 0/5] arm/arm64: smccc: Add ARCH_SOC_ID support

Hi,

This patch series adds support for SMCCCv1.2 ARCH_SOC_ID.
This doesn't add other changes added in SMCCC v1.2 yet. They will
follow these soon along with its first user SPCI/PSA-FF.

This is tested using upstream TF-A + the patch[1] fixing the original
implementation there.


v1[0]->v2:
- Incorporated comments from Steven Price in patch 5/5
- Fixed build for CONFIG_PSCI_FW=n on some arm32 platforms
- Added Steven Price's review tags

Regards,
Sudeep

[0] https://lore.kernel.org/r/[email protected]/
[1] https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4001

Sudeep Holla (5):
arm/arm64: smccc: Update link to latest SMCCC specification
arm/arm64: smccc: Add the definition for SMCCCv1.2 version/error codes
arm/arm64: smccc: Drop smccc_version enum and use ARM_SMCCC_VERSION_1_x instead
firmware: psci: Add function to fetch SMCCC version
arm/arm64: smccc: Add ARCH_SOC_ID support

arch/arm64/kernel/paravirt.c | 2 +-
drivers/firmware/psci/Kconfig | 9 ++
drivers/firmware/psci/Makefile | 1 +
drivers/firmware/psci/psci.c | 13 ++-
drivers/firmware/psci/soc_id.c | 165 +++++++++++++++++++++++++++++++++
include/linux/arm-smccc.h | 23 ++++-
include/linux/psci.h | 7 +-
7 files changed, 207 insertions(+), 13 deletions(-)
create mode 100644 drivers/firmware/psci/soc_id.c

--
2.17.1


2020-05-04 09:31:21

by Sudeep Holla

[permalink] [raw]
Subject: [PATCH v2 1/5] arm/arm64: smccc: Update link to latest SMCCC specification

The current link gets redirected to the revision B published in November
2016 though it actually points to the original revision A published in
June 2013.

Let us update the link to point to the latest version, so that it
doesn't get stale anytime soon. Currently it points to v1.2 published in
March 2020.

Reviewed-by: Steven Price <[email protected]>
Signed-off-by: Sudeep Holla <[email protected]>
---
include/linux/arm-smccc.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
index 59494df0f55b..6c1d1eda3be4 100644
--- a/include/linux/arm-smccc.h
+++ b/include/linux/arm-smccc.h
@@ -10,7 +10,7 @@
/*
* This file provides common defines for ARM SMC Calling Convention as
* specified in
- * http://infocenter.arm.com/help/topic/com.arm.doc.den0028a/index.html
+ * https://developer.arm.com/docs/den0028/latest
*/

#define ARM_SMCCC_STD_CALL _AC(0,U)
--
2.17.1

2020-05-04 09:32:20

by Sudeep Holla

[permalink] [raw]
Subject: [PATCH v2 4/5] firmware: psci: Add function to fetch SMCCC version

For backward compatibility reasons, PSCI maintains SMCCC version as
SMCCC didn't provide ARM_SMCCC_VERSION_FUNC_ID until v1.1

Let us provide accessors to fetch the SMCCC version in PSCI so that
other SMCCC v1.1+ features can use it.

Signed-off-by: Sudeep Holla <[email protected]>
---
drivers/firmware/psci/psci.c | 5 +++++
include/linux/arm-smccc.h | 9 +++++++++
2 files changed, 14 insertions(+)

diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
index 6a56d7196697..04426e16fee6 100644
--- a/drivers/firmware/psci/psci.c
+++ b/drivers/firmware/psci/psci.c
@@ -65,6 +65,11 @@ enum arm_smccc_conduit arm_smccc_1_1_get_conduit(void)
return psci_ops.conduit;
}

+u32 arm_smccc_get_version(void)
+{
+ return psci_ops.smccc_version;
+}
+
typedef unsigned long (psci_fn)(unsigned long, unsigned long,
unsigned long, unsigned long);
static psci_fn *invoke_psci_fn;
diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
index 9d9a2e42e919..d6b0f4acc707 100644
--- a/include/linux/arm-smccc.h
+++ b/include/linux/arm-smccc.h
@@ -98,6 +98,15 @@ enum arm_smccc_conduit {
*/
enum arm_smccc_conduit arm_smccc_1_1_get_conduit(void);

+/**
+ * arm_smccc_get_version()
+ *
+ * Returns the version to be used for SMCCCv1.1 or later.
+ *
+ * When SMCCCv1.1 or above is not present, assumes and returns SMCCCv1.0.
+ */
+u32 arm_smccc_get_version(void);
+
/**
* struct arm_smccc_res - Result from SMC/HVC call
* @a0-a3 result values from registers 0 to 3
--
2.17.1

2020-05-04 09:33:55

by Sudeep Holla

[permalink] [raw]
Subject: [PATCH v2 5/5] arm/arm64: smccc: Add ARCH_SOC_ID support

SMCCC v1.2 adds a new optional function SMCCC_ARCH_SOC_ID to obtain a
SiP defined SoC identification value. Add support for the same.

Also using the SoC bus infrastructure, let us expose the platform
specific SoC atrributes under sysfs. We also provide custom sysfs for
the vendor ID as JEP-106 bank and identification code.

Signed-off-by: Sudeep Holla <[email protected]>
---
drivers/firmware/psci/Kconfig | 9 ++
drivers/firmware/psci/Makefile | 1 +
drivers/firmware/psci/soc_id.c | 165 +++++++++++++++++++++++++++++++++
include/linux/arm-smccc.h | 5 +
4 files changed, 180 insertions(+)
create mode 100644 drivers/firmware/psci/soc_id.c

diff --git a/drivers/firmware/psci/Kconfig b/drivers/firmware/psci/Kconfig
index 97944168b5e6..831399338289 100644
--- a/drivers/firmware/psci/Kconfig
+++ b/drivers/firmware/psci/Kconfig
@@ -12,3 +12,12 @@ config ARM_PSCI_CHECKER
The torture tests may interfere with the PSCI checker by turning CPUs
on and off through hotplug, so for now torture tests and PSCI checker
are mutually exclusive.
+
+config ARM_SMCCC_SOC_ID
+ bool "SoC bus device for the ARM SMCCC SOC_ID"
+ depends on ARM_PSCI_FW
+ default y if ARM_PSCI_FW
+ select SOC_BUS
+ help
+ Include support for the SoC bus on the ARM SMCCC firmware based
+ platforms providing some sysfs information about the SoC variant.
diff --git a/drivers/firmware/psci/Makefile b/drivers/firmware/psci/Makefile
index 1956b882470f..55596698d1ad 100644
--- a/drivers/firmware/psci/Makefile
+++ b/drivers/firmware/psci/Makefile
@@ -2,3 +2,4 @@
#
obj-$(CONFIG_ARM_PSCI_FW) += psci.o
obj-$(CONFIG_ARM_PSCI_CHECKER) += psci_checker.o
+obj-$(CONFIG_ARM_SMCCC_SOC_ID) += soc_id.o
diff --git a/drivers/firmware/psci/soc_id.c b/drivers/firmware/psci/soc_id.c
new file mode 100644
index 000000000000..b45f2d78e12e
--- /dev/null
+++ b/drivers/firmware/psci/soc_id.c
@@ -0,0 +1,165 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2020 Arm Limited
+ */
+
+#include <linux/arm-smccc.h>
+#include <linux/bitfield.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/sys_soc.h>
+
+#define SMCCC_SOC_ID_JEP106_BANK_IDX_MASK GENMASK(30, 24)
+/*
+ * As per the spec bits[23:16] are JEP-106 identification code with parity bit
+ * for the SiP. We can drop the parity bit.
+ */
+#define SMCCC_SOC_ID_JEP106_ID_CODE_MASK GENMASK(22, 16)
+#define SMCCC_SOC_ID_IMP_DEF_SOC_ID_MASK GENMASK(15, 0)
+
+/* The bank index is equal to the for continuation code bank number - 1 */
+#define JEP106_BANK_CONT_CODE(x) \
+ (u8)(FIELD_GET(SMCCC_SOC_ID_JEP106_BANK_IDX_MASK, (x)) + 1)
+#define JEP106_ID_CODE(x) \
+ (u8)(FIELD_GET(SMCCC_SOC_ID_JEP106_ID_CODE_MASK, (x)))
+#define IMP_DEF_SOC_ID(x) \
+ (u16)(FIELD_GET(SMCCC_SOC_ID_IMP_DEF_SOC_ID_MASK, (x)))
+
+static int soc_id_version;
+static struct soc_device *soc_dev;
+static struct soc_device_attribute *soc_dev_attr;
+
+static int smccc_map_error_codes(unsigned long a0)
+{
+ if (a0 >= SMCCC_RET_SUCCESS)
+ return 0;
+ else if (a0 == SMCCC_RET_INVALID_PARAMETER)
+ return -EINVAL;
+ else if (a0 == SMCCC_RET_NOT_SUPPORTED)
+ return -EOPNOTSUPP;
+ return -EINVAL;
+}
+
+static int smccc_soc_id_support_check(void)
+{
+ struct arm_smccc_res res;
+
+ if (arm_smccc_1_1_get_conduit() == SMCCC_CONDUIT_NONE) {
+ pr_err("%s: invalid SMCCC conduit\n", __func__);
+ return -EOPNOTSUPP;
+ }
+
+ arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
+ ARM_SMCCC_ARCH_SOC_ID, &res);
+
+ return smccc_map_error_codes(res.a0);
+}
+
+static ssize_t
+jep106_cont_bank_code_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%02x\n", JEP106_BANK_CONT_CODE(soc_id_version));
+}
+
+static DEVICE_ATTR_RO(jep106_cont_bank_code);
+
+static ssize_t
+jep106_identification_code_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%02x\n", JEP106_ID_CODE(soc_id_version));
+}
+
+static DEVICE_ATTR_RO(jep106_identification_code);
+
+static struct attribute *jep106_id_attrs[] = {
+ &dev_attr_jep106_cont_bank_code.attr,
+ &dev_attr_jep106_identification_code.attr,
+ NULL
+};
+
+ATTRIBUTE_GROUPS(jep106_id);
+
+static int __init smccc_soc_init(void)
+{
+ struct device *dev;
+ int ret, soc_id_rev;
+ struct arm_smccc_res res;
+ static char soc_id_str[8], soc_id_rev_str[12];
+
+ if (arm_smccc_get_version() < ARM_SMCCC_VERSION_1_2)
+ return 0;
+
+ ret = smccc_soc_id_support_check();
+ if (ret) {
+ pr_info("SMCCC SOC_ID not implemented, skipping ....\n");
+ return 0;
+ }
+
+ arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_SOC_ID, 0, &res);
+
+ ret = smccc_map_error_codes(res.a0);
+ if (ret) {
+ pr_info("SMCCC SOC_ID: failed to version, Err = %d\n", ret);
+ return ret;
+ }
+
+ soc_id_version = res.a0;
+
+ arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_SOC_ID, 1, &res);
+
+ ret = smccc_map_error_codes(res.a0);
+ if (ret) {
+ pr_info("SMCCC SOC_ID: failed to revision, Err = %d\n", ret);
+ return ret;
+ }
+
+ soc_id_rev = res.a0;
+
+ soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
+ if (!soc_dev_attr)
+ return -ENOMEM;
+
+ sprintf(soc_id_str, "0x%04x", IMP_DEF_SOC_ID(soc_id_version));
+ sprintf(soc_id_rev_str, "0x%08x", soc_id_rev);
+
+ soc_dev_attr->soc_id = soc_id_str;
+ soc_dev_attr->revision = soc_id_rev_str;
+
+ soc_dev = soc_device_register(soc_dev_attr);
+ if (IS_ERR(soc_dev)) {
+ ret = PTR_ERR(soc_dev);
+ goto free_soc;
+ }
+
+ dev = soc_device_to_device(soc_dev);
+
+ ret = devm_device_add_groups(dev, jep106_id_groups);
+ if (ret) {
+ dev_err(dev, "sysfs create failed: %d\n", ret);
+ goto unregister_soc;
+ }
+
+ pr_info("SMCCC SoC ID: %s Revision %s\n", soc_dev_attr->soc_id,
+ soc_dev_attr->revision);
+
+ return 0;
+
+unregister_soc:
+ soc_device_unregister(soc_dev);
+free_soc:
+ kfree(soc_dev_attr);
+ return ret;
+}
+module_init(smccc_soc_init);
+
+static void __exit smccc_soc_exit(void)
+{
+ if (soc_dev)
+ soc_device_unregister(soc_dev);
+ kfree(soc_dev_attr);
+}
+module_exit(smccc_soc_exit);
diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
index d6b0f4acc707..04414fc2000f 100644
--- a/include/linux/arm-smccc.h
+++ b/include/linux/arm-smccc.h
@@ -68,6 +68,11 @@
ARM_SMCCC_SMC_32, \
0, 1)

+#define ARM_SMCCC_ARCH_SOC_ID \
+ ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
+ ARM_SMCCC_SMC_32, \
+ 0, 2)
+
#define ARM_SMCCC_ARCH_WORKAROUND_1 \
ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
ARM_SMCCC_SMC_32, \
--
2.17.1