DOE r1.1 replaced all occurrences of "protocol" with the term "feature"
or "Data Object Type".
PCIe r6.1 (which was published July 24) incorporated that change.
Rename the existing terms protocol with feature.
Signed-off-by: Alistair Francis <[email protected]>
Reviewed-by: Jonathan Cameron <[email protected]>
Reviewed-by: Lukas Wunner <[email protected]>
---
v11:
- No changes
v10:
- Split original patch into two
v9:
- Rename two more DOE macros
v8:
- Rename prot to feat as well
v7:
- Initial patch
drivers/pci/doe.c | 88 +++++++++++++++++++++++------------------------
1 file changed, 44 insertions(+), 44 deletions(-)
diff --git a/drivers/pci/doe.c b/drivers/pci/doe.c
index 652d63df9d22..f776f5304a3e 100644
--- a/drivers/pci/doe.c
+++ b/drivers/pci/doe.c
@@ -22,7 +22,7 @@
#include "pci.h"
-#define PCI_DOE_PROTOCOL_DISCOVERY 0
+#define PCI_DOE_FEATURE_DISCOVERY 0
/* Timeout of 1 second from 6.30.2 Operation, PCI Spec r6.0 */
#define PCI_DOE_TIMEOUT HZ
@@ -43,7 +43,7 @@
*
* @pdev: PCI device this mailbox belongs to
* @cap_offset: Capability offset
- * @prots: Array of protocols supported (encoded as long values)
+ * @feats: Array of features supported (encoded as long values)
* @wq: Wait queue for work item
* @work_queue: Queue of pci_doe_work items
* @flags: Bit array of PCI_DOE_FLAG_* flags
@@ -51,14 +51,14 @@
struct pci_doe_mb {
struct pci_dev *pdev;
u16 cap_offset;
- struct xarray prots;
+ struct xarray feats;
wait_queue_head_t wq;
struct workqueue_struct *work_queue;
unsigned long flags;
};
-struct pci_doe_protocol {
+struct pci_doe_feature {
u16 vid;
u8 type;
};
@@ -66,7 +66,7 @@ struct pci_doe_protocol {
/**
* struct pci_doe_task - represents a single query/response
*
- * @prot: DOE Protocol
+ * @feat: DOE Feature
* @request_pl: The request payload
* @request_pl_sz: Size of the request payload (bytes)
* @response_pl: The response payload
@@ -78,7 +78,7 @@ struct pci_doe_protocol {
* @doe_mb: Used internally by the mailbox
*/
struct pci_doe_task {
- struct pci_doe_protocol prot;
+ struct pci_doe_feature feat;
const __le32 *request_pl;
size_t request_pl_sz;
__le32 *response_pl;
@@ -171,8 +171,8 @@ static int pci_doe_send_req(struct pci_doe_mb *doe_mb,
length = 0;
/* Write DOE Header */
- val = FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_1_VID, task->prot.vid) |
- FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_1_TYPE, task->prot.type);
+ val = FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_1_VID, task->feat.vid) |
+ FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_1_TYPE, task->feat.type);
pci_write_config_dword(pdev, offset + PCI_DOE_WRITE, val);
pci_write_config_dword(pdev, offset + PCI_DOE_WRITE,
FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_2_LENGTH,
@@ -217,12 +217,12 @@ static int pci_doe_recv_resp(struct pci_doe_mb *doe_mb, struct pci_doe_task *tas
int i = 0;
u32 val;
- /* Read the first dword to get the protocol */
+ /* Read the first dword to get the feature */
pci_read_config_dword(pdev, offset + PCI_DOE_READ, &val);
- if ((FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_VID, val) != task->prot.vid) ||
- (FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_TYPE, val) != task->prot.type)) {
- dev_err_ratelimited(&pdev->dev, "[%x] expected [VID, Protocol] = [%04x, %02x], got [%04x, %02x]\n",
- doe_mb->cap_offset, task->prot.vid, task->prot.type,
+ if ((FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_VID, val) != task->feat.vid) ||
+ (FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_TYPE, val) != task->feat.type)) {
+ dev_err_ratelimited(&pdev->dev, "[%x] expected [VID, Feature] = [%04x, %02x], got [%04x, %02x]\n",
+ doe_mb->cap_offset, task->feat.vid, task->feat.type,
FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_VID, val),
FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_TYPE, val));
return -EIO;
@@ -384,7 +384,7 @@ static void pci_doe_task_complete(struct pci_doe_task *task)
}
static int pci_doe_discovery(struct pci_doe_mb *doe_mb, u8 capver, u8 *index, u16 *vid,
- u8 *protocol)
+ u8 *feature)
{
u32 request_pl = FIELD_PREP(PCI_DOE_DATA_OBJECT_DISC_REQ_3_INDEX,
*index) |
@@ -395,7 +395,7 @@ static int pci_doe_discovery(struct pci_doe_mb *doe_mb, u8 capver, u8 *index, u1
u32 response_pl;
int rc;
- rc = pci_doe(doe_mb, PCI_VENDOR_ID_PCI_SIG, PCI_DOE_PROTOCOL_DISCOVERY,
+ rc = pci_doe(doe_mb, PCI_VENDOR_ID_PCI_SIG, PCI_DOE_FEATURE_DISCOVERY,
&request_pl_le, sizeof(request_pl_le),
&response_pl_le, sizeof(response_pl_le));
if (rc < 0)
@@ -406,7 +406,7 @@ static int pci_doe_discovery(struct pci_doe_mb *doe_mb, u8 capver, u8 *index, u1
response_pl = le32_to_cpu(response_pl_le);
*vid = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_VID, response_pl);
- *protocol = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_PROTOCOL,
+ *feature = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_PROTOCOL,
response_pl);
*index = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_NEXT_INDEX,
response_pl);
@@ -414,12 +414,12 @@ static int pci_doe_discovery(struct pci_doe_mb *doe_mb, u8 capver, u8 *index, u1
return 0;
}
-static void *pci_doe_xa_prot_entry(u16 vid, u8 prot)
+static void *pci_doe_xa_feat_entry(u16 vid, u8 prot)
{
return xa_mk_value((vid << 8) | prot);
}
-static int pci_doe_cache_protocols(struct pci_doe_mb *doe_mb)
+static int pci_doe_cache_features(struct pci_doe_mb *doe_mb)
{
u8 index = 0;
u8 xa_idx = 0;
@@ -438,11 +438,11 @@ static int pci_doe_cache_protocols(struct pci_doe_mb *doe_mb)
return rc;
pci_dbg(doe_mb->pdev,
- "[%x] Found protocol %d vid: %x prot: %x\n",
+ "[%x] Found feature %d vid: %x prot: %x\n",
doe_mb->cap_offset, xa_idx, vid, prot);
- rc = xa_insert(&doe_mb->prots, xa_idx++,
- pci_doe_xa_prot_entry(vid, prot), GFP_KERNEL);
+ rc = xa_insert(&doe_mb->feats, xa_idx++,
+ pci_doe_xa_feat_entry(vid, prot), GFP_KERNEL);
if (rc)
return rc;
} while (index);
@@ -466,7 +466,7 @@ static void pci_doe_cancel_tasks(struct pci_doe_mb *doe_mb)
* @pdev: PCI device to create the DOE mailbox for
* @cap_offset: Offset of the DOE mailbox
*
- * Create a single mailbox object to manage the mailbox protocol at the
+ * Create a single mailbox object to manage the mailbox feature at the
* cap_offset specified.
*
* RETURNS: created mailbox object on success
@@ -485,7 +485,7 @@ static struct pci_doe_mb *pci_doe_create_mb(struct pci_dev *pdev,
doe_mb->pdev = pdev;
doe_mb->cap_offset = cap_offset;
init_waitqueue_head(&doe_mb->wq);
- xa_init(&doe_mb->prots);
+ xa_init(&doe_mb->feats);
doe_mb->work_queue = alloc_ordered_workqueue("%s %s DOE [%x]", 0,
dev_bus_name(&pdev->dev),
@@ -508,11 +508,11 @@ static struct pci_doe_mb *pci_doe_create_mb(struct pci_dev *pdev,
/*
* The state machine and the mailbox should be in sync now;
- * Use the mailbox to query protocols.
+ * Use the mailbox to query features.
*/
- rc = pci_doe_cache_protocols(doe_mb);
+ rc = pci_doe_cache_features(doe_mb);
if (rc) {
- pci_err(pdev, "[%x] failed to cache protocols : %d\n",
+ pci_err(pdev, "[%x] failed to cache features : %d\n",
doe_mb->cap_offset, rc);
goto err_cancel;
}
@@ -521,7 +521,7 @@ static struct pci_doe_mb *pci_doe_create_mb(struct pci_dev *pdev,
err_cancel:
pci_doe_cancel_tasks(doe_mb);
- xa_destroy(&doe_mb->prots);
+ xa_destroy(&doe_mb->feats);
err_destroy_wq:
destroy_workqueue(doe_mb->work_queue);
err_free:
@@ -539,31 +539,31 @@ static struct pci_doe_mb *pci_doe_create_mb(struct pci_dev *pdev,
static void pci_doe_destroy_mb(struct pci_doe_mb *doe_mb)
{
pci_doe_cancel_tasks(doe_mb);
- xa_destroy(&doe_mb->prots);
+ xa_destroy(&doe_mb->feats);
destroy_workqueue(doe_mb->work_queue);
kfree(doe_mb);
}
/**
- * pci_doe_supports_prot() - Return if the DOE instance supports the given
- * protocol
+ * pci_doe_supports_feat() - Return if the DOE instance supports the given
+ * feature
* @doe_mb: DOE mailbox capability to query
- * @vid: Protocol Vendor ID
- * @type: Protocol type
+ * @vid: Feature Vendor ID
+ * @type: Feature type
*
- * RETURNS: True if the DOE mailbox supports the protocol specified
+ * RETURNS: True if the DOE mailbox supports the feature specified
*/
-static bool pci_doe_supports_prot(struct pci_doe_mb *doe_mb, u16 vid, u8 type)
+static bool pci_doe_supports_feat(struct pci_doe_mb *doe_mb, u16 vid, u8 type)
{
unsigned long index;
void *entry;
- /* The discovery protocol must always be supported */
- if (vid == PCI_VENDOR_ID_PCI_SIG && type == PCI_DOE_PROTOCOL_DISCOVERY)
+ /* The discovery feature must always be supported */
+ if (vid == PCI_VENDOR_ID_PCI_SIG && type == PCI_DOE_FEATURE_DISCOVERY)
return true;
- xa_for_each(&doe_mb->prots, index, entry)
- if (entry == pci_doe_xa_prot_entry(vid, type))
+ xa_for_each(&doe_mb->feats, index, entry)
+ if (entry == pci_doe_xa_feat_entry(vid, type))
return true;
return false;
@@ -591,7 +591,7 @@ static bool pci_doe_supports_prot(struct pci_doe_mb *doe_mb, u16 vid, u8 type)
static int pci_doe_submit_task(struct pci_doe_mb *doe_mb,
struct pci_doe_task *task)
{
- if (!pci_doe_supports_prot(doe_mb, task->prot.vid, task->prot.type))
+ if (!pci_doe_supports_feat(doe_mb, task->feat.vid, task->feat.type))
return -EINVAL;
if (test_bit(PCI_DOE_FLAG_DEAD, &doe_mb->flags))
@@ -637,8 +637,8 @@ int pci_doe(struct pci_doe_mb *doe_mb, u16 vendor, u8 type,
{
DECLARE_COMPLETION_ONSTACK(c);
struct pci_doe_task task = {
- .prot.vid = vendor,
- .prot.type = type,
+ .feat.vid = vendor,
+ .feat.type = type,
.request_pl = request,
.request_pl_sz = request_sz,
.response_pl = response,
@@ -663,9 +663,9 @@ EXPORT_SYMBOL_GPL(pci_doe);
*
* @pdev: PCI device
* @vendor: Vendor ID
- * @type: Data Object Type
+ * @prot: Data Object Type
*
- * Find first DOE mailbox of a PCI device which supports the given protocol.
+ * Find first DOE mailbox of a PCI device which supports the given feature.
*
* RETURNS: Pointer to the DOE mailbox or NULL if none was found.
*/
@@ -676,7 +676,7 @@ struct pci_doe_mb *pci_find_doe_mailbox(struct pci_dev *pdev, u16 vendor,
unsigned long index;
xa_for_each(&pdev->doe_mbs, index, doe_mb)
- if (pci_doe_supports_prot(doe_mb, vendor, type))
+ if (pci_doe_supports_feat(doe_mb, vendor, type))
return doe_mb;
return NULL;
--
2.45.2
PCIe r6.1 (which was published July 24) describes a "Vendor ID", a
"Data Object Type" and "Next Index" as the fields in the DOE
Discovery Response Data Object. The DOE driver currently uses
both the terms type and prot for the second element.
This patch renames all uses of the DOE Discovery Response Data Object
to use type as the second element of the object header, instead of
type/prot as it currently is.
Signed-off-by: Alistair Francis <[email protected]>
---
v11:
- Avoid breaking changes to userspace header
v10:
- Split original patch into two
v9:
- Rename two more DOE macros
v8:
- Rename prot to feat as well
v7:
- Initial patch
drivers/pci/doe.c | 18 +++++++++---------
include/uapi/linux/pci_regs.h | 5 ++++-
2 files changed, 13 insertions(+), 10 deletions(-)
diff --git a/drivers/pci/doe.c b/drivers/pci/doe.c
index f776f5304a3e..defc4be81bd4 100644
--- a/drivers/pci/doe.c
+++ b/drivers/pci/doe.c
@@ -406,7 +406,7 @@ static int pci_doe_discovery(struct pci_doe_mb *doe_mb, u8 capver, u8 *index, u1
response_pl = le32_to_cpu(response_pl_le);
*vid = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_VID, response_pl);
- *feature = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_PROTOCOL,
+ *feature = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_TYPE,
response_pl);
*index = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_NEXT_INDEX,
response_pl);
@@ -414,9 +414,9 @@ static int pci_doe_discovery(struct pci_doe_mb *doe_mb, u8 capver, u8 *index, u1
return 0;
}
-static void *pci_doe_xa_feat_entry(u16 vid, u8 prot)
+static void *pci_doe_xa_feat_entry(u16 vid, u8 type)
{
- return xa_mk_value((vid << 8) | prot);
+ return xa_mk_value((vid << 8) | type);
}
static int pci_doe_cache_features(struct pci_doe_mb *doe_mb)
@@ -430,19 +430,19 @@ static int pci_doe_cache_features(struct pci_doe_mb *doe_mb)
do {
int rc;
u16 vid;
- u8 prot;
+ u8 type;
rc = pci_doe_discovery(doe_mb, PCI_EXT_CAP_VER(hdr), &index,
- &vid, &prot);
+ &vid, &type);
if (rc)
return rc;
pci_dbg(doe_mb->pdev,
- "[%x] Found feature %d vid: %x prot: %x\n",
- doe_mb->cap_offset, xa_idx, vid, prot);
+ "[%x] Found feature %d vid: %x type: %x\n",
+ doe_mb->cap_offset, xa_idx, vid, type);
rc = xa_insert(&doe_mb->feats, xa_idx++,
- pci_doe_xa_feat_entry(vid, prot), GFP_KERNEL);
+ pci_doe_xa_feat_entry(vid, type), GFP_KERNEL);
if (rc)
return rc;
} while (index);
@@ -663,7 +663,7 @@ EXPORT_SYMBOL_GPL(pci_doe);
*
* @pdev: PCI device
* @vendor: Vendor ID
- * @prot: Data Object Type
+ * @type: Data Object Type
*
* Find first DOE mailbox of a PCI device which supports the given feature.
*
diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
index 94c00996e633..ca692a3e1e5e 100644
--- a/include/uapi/linux/pci_regs.h
+++ b/include/uapi/linux/pci_regs.h
@@ -1146,9 +1146,12 @@
#define PCI_DOE_DATA_OBJECT_DISC_REQ_3_INDEX 0x000000ff
#define PCI_DOE_DATA_OBJECT_DISC_REQ_3_VER 0x0000ff00
#define PCI_DOE_DATA_OBJECT_DISC_RSP_3_VID 0x0000ffff
-#define PCI_DOE_DATA_OBJECT_DISC_RSP_3_PROTOCOL 0x00ff0000
+#define PCI_DOE_DATA_OBJECT_DISC_RSP_3_TYPE 0x00ff0000
#define PCI_DOE_DATA_OBJECT_DISC_RSP_3_NEXT_INDEX 0xff000000
+/* Deprecated old name, replaced with PCI_DOE_DATA_OBJECT_DISC_RSP_3_TYPE */
+#define PCI_DOE_DATA_OBJECT_DISC_RSP_3_PROTOCOL 0x00ff0000
+
/* Compute Express Link (CXL r3.1, sec 8.1.5) */
#define PCI_DVSEC_CXL_PORT 3
#define PCI_DVSEC_CXL_PORT_CTL 0x0c
--
2.45.2
The PCIe 6 specification added support for the Data Object
Exchange (DOE).
When DOE is supported the DOE Discovery Feature must be implemented per
PCIe r6.1 sec 6.30.1.1. The protocol allows a requester to obtain
information about the other DOE features supported by the device.
The kernel is already querying the DOE features supported and cacheing
the values. Expose the values in sysfs to allow user space to
determine which DOE features are supported by the PCIe device.
By exposing the information to userspace tools like lspci can relay the
information to users. By listing all of the supported features we can
allow userspace to parse the list, which might include
vendor specific features as well as yet to be supported features.
As the DOE Discovery feature must always be supported we treat it as a
special named attribute case. This allows the usual PCI attribute_group
handling to correctly create the doe_features directory when registering
pci_doe_sysfs_group (otherwise it doesn't and sysfs_add_file_to_group()
will seg fault).
After this patch is supported you can see something like this when
attaching a DOE device
$ ls /sys/devices/pci0000:00/0000:00:02.0//doe*
0001:01 0001:02 doe_discovery
Signed-off-by: Alistair Francis <[email protected]>
---
v11:
- Gracefully handle multiple entried of same feature
- Minor fixes and code cleanups
v10:
- Rebase to use DEFINE_SYSFS_GROUP_VISIBLE and remove
special setup function
v9:
- Add a teardown function
- Rename functions to be clearer
- Tidy up the commit message
- Remove #ifdef from header
v8:
- Inlucde an example in the docs
- Fixup removing a file that wasn't added
- Remove a blank line
v7:
- Fixup the #ifdefs to keep the test robot happy
v6:
- Use "feature" instead of protocol
- Don't use any devm_* functions
- Add two more patches to the series
v5:
- Return the file name as the file contents
- Code cleanups and simplifications
v4:
- Fixup typos in the documentation
- Make it clear that the file names contain the information
- Small code cleanups
- Remove most #ifdefs
- Remove extra NULL assignment
v3:
- Expose each DOE feature as a separate file
v2:
- Add documentation
- Code cleanups
Documentation/ABI/testing/sysfs-bus-pci | 28 ++++
drivers/pci/doe.c | 179 ++++++++++++++++++++++++
drivers/pci/pci-sysfs.c | 13 ++
drivers/pci/pci.h | 10 ++
4 files changed, 230 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index ecf47559f495..65a3238ab701 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -500,3 +500,31 @@ Description:
console drivers from the device. Raw users of pci-sysfs
resourceN attributes must be terminated prior to resizing.
Success of the resizing operation is not guaranteed.
+
+What: /sys/bus/pci/devices/.../doe_features
+Date: May 2024
+Contact: Linux PCI developers <[email protected]>
+Description:
+ This directory contains a list of the supported
+ Data Object Exchange (DOE) features. The features are
+ the file name. The contents of each file is the raw vendor id and
+ data object feature values.
+
+ The value comes from the device and specifies the vendor and
+ data object type supported. The lower (RHS of the colon) is
+ the data object type in hex. The upper (LHS of the colon)
+ is the vendor ID.
+
+ As all DOE devices must support the DOE discovery protocol, if
+ DOE is supported you will at least see the doe_discovery file, with
+ this contents
+
+ # cat doe_features/doe_discovery
+ 0001:00
+
+ If the device supports other protocols you will see other files
+ as well. For example is CMA/SPDM and secure CMA/SPDM are supported
+ the doe_features directory will look like this
+
+ # ls doe_features
+ 0001:01 0001:02 doe_discovery
diff --git a/drivers/pci/doe.c b/drivers/pci/doe.c
index defc4be81bd4..9858b709c020 100644
--- a/drivers/pci/doe.c
+++ b/drivers/pci/doe.c
@@ -14,6 +14,7 @@
#include <linux/bitfield.h>
#include <linux/delay.h>
+#include <linux/device.h>
#include <linux/jiffies.h>
#include <linux/mutex.h>
#include <linux/pci.h>
@@ -47,6 +48,7 @@
* @wq: Wait queue for work item
* @work_queue: Queue of pci_doe_work items
* @flags: Bit array of PCI_DOE_FLAG_* flags
+ * @sysfs_attrs: Array of sysfs device attributes
*/
struct pci_doe_mb {
struct pci_dev *pdev;
@@ -56,6 +58,10 @@ struct pci_doe_mb {
wait_queue_head_t wq;
struct workqueue_struct *work_queue;
unsigned long flags;
+
+#ifdef CONFIG_SYSFS
+ struct device_attribute *sysfs_attrs;
+#endif
};
struct pci_doe_feature {
@@ -92,6 +98,179 @@ struct pci_doe_task {
struct pci_doe_mb *doe_mb;
};
+#ifdef CONFIG_SYSFS
+static ssize_t doe_discovery_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return sysfs_emit(buf, "0001:00\n");
+}
+DEVICE_ATTR_RO(doe_discovery);
+
+static struct attribute *pci_doe_sysfs_feature_attrs[] = {
+ &dev_attr_doe_discovery.attr,
+ NULL
+};
+
+static umode_t pci_doe_features_sysfs_attr_visible(struct kobject *kobj,
+ struct attribute *a, int n)
+{
+ struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
+ struct pci_doe_mb *doe_mb;
+ unsigned long index, j;
+ unsigned long vid, type;
+ void *entry;
+
+ xa_for_each(&pdev->doe_mbs, index, doe_mb) {
+ xa_for_each(&doe_mb->feats, j, entry) {
+ vid = xa_to_value(entry) >> 8;
+ type = xa_to_value(entry) & 0xFF;
+
+ if (vid == 0x01 && type == 0x00) {
+ /*
+ * This is the DOE discovery protocol
+ * Every DOE instance must support this, so we
+ * give it a useful name.
+ */
+ return a->mode;
+ }
+ }
+ }
+
+ return 0;
+}
+
+static bool pci_doe_features_sysfs_group_visible(struct kobject *kobj)
+{
+ struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
+ struct pci_doe_mb *doe_mb;
+ unsigned long index;
+
+ xa_for_each(&pdev->doe_mbs, index, doe_mb) {
+ if (!xa_empty(&doe_mb->feats))
+ return true;
+ }
+
+ return false;
+}
+DEFINE_SYSFS_GROUP_VISIBLE(pci_doe_features_sysfs)
+
+const struct attribute_group pci_doe_sysfs_group = {
+ .name = "doe_features",
+ .attrs = pci_doe_sysfs_feature_attrs,
+ .is_visible = SYSFS_GROUP_VISIBLE(pci_doe_features_sysfs),
+};
+
+static ssize_t pci_doe_sysfs_feature_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return sysfs_emit(buf, "%s\n", attr->attr.name);
+}
+
+static void pci_doe_sysfs_feature_remove(struct pci_dev *pdev,
+ struct pci_doe_mb *doe_mb)
+{
+ struct device_attribute *attrs = doe_mb->sysfs_attrs;
+ struct device *dev = &pdev->dev;
+ unsigned long i;
+ void *entry;
+
+ if (!attrs)
+ return;
+
+ doe_mb->sysfs_attrs = NULL;
+ xa_for_each(&doe_mb->feats, i, entry) {
+ if (attrs[i].show)
+ sysfs_remove_file_from_group(&dev->kobj, &attrs[i].attr,
+ pci_doe_sysfs_group.name);
+ kfree(attrs[i].attr.name);
+ }
+ kfree(attrs);
+}
+
+static int pci_doe_sysfs_feature_populate(struct pci_dev *pdev,
+ struct pci_doe_mb *doe_mb)
+{
+ struct device *dev = &pdev->dev;
+ struct device_attribute *attrs;
+ unsigned long num_features = 0;
+ unsigned long vid, type;
+ unsigned long i;
+ void *entry;
+ int ret;
+
+ xa_for_each(&doe_mb->feats, i, entry)
+ num_features++;
+
+ attrs = kcalloc(num_features, sizeof(*attrs), GFP_KERNEL);
+ if (!attrs)
+ return -ENOMEM;
+
+ doe_mb->sysfs_attrs = attrs;
+ xa_for_each(&doe_mb->feats, i, entry) {
+ sysfs_attr_init(&attrs[i].attr);
+ vid = xa_to_value(entry) >> 8;
+ type = xa_to_value(entry) & 0xFF;
+
+ if (vid == 0x01 && type == 0x00) {
+ /* DOE Discovery, manually displayed by `dev_attr_doe_discovery` */
+ continue;
+ }
+
+ attrs[i].attr.name = kasprintf(GFP_KERNEL,
+ "%04lx:%02lx", vid, type);
+ if (!attrs[i].attr.name) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+
+ attrs[i].attr.mode = 0444;
+ attrs[i].show = pci_doe_sysfs_feature_show;
+
+ ret = sysfs_add_file_to_group(&dev->kobj, &attrs[i].attr,
+ pci_doe_sysfs_group.name);
+ if (ret) {
+ attrs[i].show = NULL;
+ if (ret != -EEXIST)
+ goto fail;
+ else
+ kfree(attrs[i].attr.name);
+ }
+ }
+
+ return 0;
+
+fail:
+ pci_doe_sysfs_feature_remove(pdev, doe_mb);
+ return ret;
+}
+
+void pci_doe_sysfs_teardown(struct pci_dev *pdev)
+{
+ struct pci_doe_mb *doe_mb;
+ unsigned long index;
+
+ xa_for_each(&pdev->doe_mbs, index, doe_mb)
+ pci_doe_sysfs_feature_remove(pdev, doe_mb);
+}
+
+int pci_doe_sysfs_init(struct pci_dev *pdev)
+{
+ struct pci_doe_mb *doe_mb;
+ unsigned long index;
+ int ret;
+
+ xa_for_each(&pdev->doe_mbs, index, doe_mb) {
+ ret = pci_doe_sysfs_feature_populate(pdev, doe_mb);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+#endif
+
static int pci_doe_wait(struct pci_doe_mb *doe_mb, unsigned long timeout)
{
if (wait_event_timeout(doe_mb->wq,
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 40cfa716392f..b5db191cb29f 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -16,6 +16,7 @@
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/pci.h>
+#include <linux/pci-doe.h>
#include <linux/stat.h>
#include <linux/export.h>
#include <linux/topology.h>
@@ -1143,6 +1144,9 @@ static void pci_remove_resource_files(struct pci_dev *pdev)
{
int i;
+ if (IS_ENABLED(CONFIG_PCI_DOE))
+ pci_doe_sysfs_teardown(pdev);
+
for (i = 0; i < PCI_STD_NUM_BARS; i++) {
struct bin_attribute *res_attr;
@@ -1227,6 +1231,12 @@ static int pci_create_resource_files(struct pci_dev *pdev)
int i;
int retval;
+ if (IS_ENABLED(CONFIG_PCI_DOE)) {
+ retval = pci_doe_sysfs_init(pdev);
+ if (retval)
+ return retval;
+ }
+
/* Expose the PCI resources from this device as files */
for (i = 0; i < PCI_STD_NUM_BARS; i++) {
@@ -1661,6 +1671,9 @@ const struct attribute_group *pci_dev_attr_groups[] = {
#endif
#ifdef CONFIG_PCIEASPM
&aspm_ctrl_attr_group,
+#endif
+#ifdef CONFIG_PCI_DOE
+ &pci_doe_sysfs_group,
#endif
NULL,
};
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index fd44565c4756..3aee231dcb0c 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -189,6 +189,7 @@ extern const struct attribute_group *pci_dev_groups[];
extern const struct attribute_group *pci_dev_attr_groups[];
extern const struct attribute_group *pcibus_groups[];
extern const struct attribute_group *pci_bus_groups[];
+extern const struct attribute_group pci_doe_sysfs_group;
#else
static inline int pci_create_sysfs_dev_files(struct pci_dev *pdev) { return 0; }
static inline void pci_remove_sysfs_dev_files(struct pci_dev *pdev) { }
@@ -196,6 +197,7 @@ static inline void pci_remove_sysfs_dev_files(struct pci_dev *pdev) { }
#define pci_dev_attr_groups NULL
#define pcibus_groups NULL
#define pci_bus_groups NULL
+#define pci_doe_sysfs_group NULL
#endif
extern unsigned long pci_hotplug_io_size;
@@ -333,6 +335,14 @@ static inline void pci_doe_destroy(struct pci_dev *pdev) { }
static inline void pci_doe_disconnected(struct pci_dev *pdev) { }
#endif
+#if defined(CONFIG_PCI_DOE) && defined(CONFIG_SYSFS)
+int pci_doe_sysfs_init(struct pci_dev *pci_dev);
+void pci_doe_sysfs_teardown(struct pci_dev *pdev);
+#else
+static inline int pci_doe_sysfs_init(struct pci_dev *pdev) { return 0; }
+static inline void pci_doe_sysfs_teardown(struct pci_dev *pdev) { }
+#endif
+
/**
* pci_dev_set_io_state - Set the new error state if possible.
*
--
2.45.2
PCIe devices (not CXL) can support DOE as well, so allow DOE to be
enabled even if CXL isn't.
Signed-off-by: Alistair Francis <[email protected]>
Reviewed-by: Jonathan Cameron <[email protected]>
---
drivers/pci/Kconfig | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index d35001589d88..09d3f5c8555c 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -122,7 +122,10 @@ config PCI_ATS
bool
config PCI_DOE
- bool
+ bool "Enable PCI Data Object Exchange (DOE) support"
+ help
+ Say Y here if you want be able to communicate with PCIe DOE
+ mailboxes.
config PCI_ECAM
bool
--
2.45.2
On Fri, Jun 14, 2024 at 10:12:43AM +1000, Alistair Francis wrote:
> --- a/drivers/pci/pci-sysfs.c
> +++ b/drivers/pci/pci-sysfs.c
> @@ -16,6 +16,7 @@
> #include <linux/kernel.h>
> #include <linux/sched.h>
> #include <linux/pci.h>
> +#include <linux/pci-doe.h>
> #include <linux/stat.h>
> #include <linux/export.h>
> #include <linux/topology.h>
I'm not seeing any symbols used here which are defined in pci-doe.h.
Am I missing something?
If not this additional #include can be dropped.
> @@ -1143,6 +1144,9 @@ static void pci_remove_resource_files(struct pci_dev *pdev)
> {
> int i;
>
> + if (IS_ENABLED(CONFIG_PCI_DOE))
> + pci_doe_sysfs_teardown(pdev);
> +
No need to constrain to "if (IS_ENABLED(CONFIG_PCI_DOE))" as you're
defining an empty static inline in the header file.
> @@ -1227,6 +1231,12 @@ static int pci_create_resource_files(struct pci_dev *pdev)
> int i;
> int retval;
>
> + if (IS_ENABLED(CONFIG_PCI_DOE)) {
> + retval = pci_doe_sysfs_init(pdev);
> + if (retval)
> + return retval;
> + }
> +
Same here.
Note that pci_{create,remove}_resource_files() is not the right place
to dynamically add sysfs attributes. These functions are called very
late to postpone exposure of ROM resources until they're enumerated.
You want to add your sysfs attributes right after device_add() has been
called and you want to remove them right before device_del() is called.
See here for an example how it's done correctly:
https://lore.kernel.org/all/[email protected]/
(Search for the call to pci_npem_create() in pci_device_add() and
pci_npem_remove() in pci_destroy_dev().)
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -189,6 +189,7 @@ extern const struct attribute_group *pci_dev_groups[];
> extern const struct attribute_group *pci_dev_attr_groups[];
> extern const struct attribute_group *pcibus_groups[];
> extern const struct attribute_group *pci_bus_groups[];
> +extern const struct attribute_group pci_doe_sysfs_group;
> #else
> static inline int pci_create_sysfs_dev_files(struct pci_dev *pdev) { return 0; }
> static inline void pci_remove_sysfs_dev_files(struct pci_dev *pdev) { }
> @@ -196,6 +197,7 @@ static inline void pci_remove_sysfs_dev_files(struct pci_dev *pdev) { }
> #define pci_dev_attr_groups NULL
> #define pcibus_groups NULL
> #define pci_bus_groups NULL
> +#define pci_doe_sysfs_group NULL
> #endif
You only need the "extern const struct ..." definition, not the
NULL definition. The reason we have these NULL definitions is
because we're referencing the attribute groups in files which
are compiled even if CONFIG_SYSFS=n. But I believe that's not
the case here.
Thanks,
Lukas
On Fri, Jun 14, 2024 at 10:12:43AM +1000, Alistair Francis wrote:
> --- a/drivers/pci/doe.c
> +++ b/drivers/pci/doe.c
[...]
> +#ifdef CONFIG_SYSFS
> +static ssize_t doe_discovery_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + return sysfs_emit(buf, "0001:00\n");
> +}
> +DEVICE_ATTR_RO(doe_discovery);
If you want to use "0001:00" as filename but can't because
"0001:00_show()" would not be a valid function name in C,
I think there's no harm in manually expanding the macro to:
struct device_attribute dev_attr_doe_discovery = \
__ATTR(0001:00, 0444, pci_doe_sysfs_feature_show, NULL);
That also avoids the need to have an extra doe_discovery_show()
function.
Intuitively, when I saw there's a "doe_discovery" attribute,
my first thought was: "Oh maybe I need to write something there
to (re-)initiate DOE discovery?"
> +static umode_t pci_doe_features_sysfs_attr_visible(struct kobject *kobj,
> + struct attribute *a, int n)
> +{
> + struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
> + struct pci_doe_mb *doe_mb;
> + unsigned long index, j;
> + unsigned long vid, type;
> + void *entry;
> +
> + xa_for_each(&pdev->doe_mbs, index, doe_mb) {
> + xa_for_each(&doe_mb->feats, j, entry) {
> + vid = xa_to_value(entry) >> 8;
> + type = xa_to_value(entry) & 0xFF;
> +
> + if (vid == 0x01 && type == 0x00) {
Wherever possible, PCI_VENDOR_ID_PCI_SIG and PCI_DOE_PROTOCOL_DISCOVERY
macros should be used in lieu of 0x0001 and 0x00.
> + /*
> + * This is the DOE discovery protocol
> + * Every DOE instance must support this, so we
> + * give it a useful name.
> + */
> + return a->mode;
> + }
> + }
> + }
> +
> + return 0;
> +}
I agree with Jonathan that at first glance one would assume that
this function just always returns a->mode.
> +static bool pci_doe_features_sysfs_group_visible(struct kobject *kobj)
> +{
> + struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
> + struct pci_doe_mb *doe_mb;
> + unsigned long index;
> +
> + xa_for_each(&pdev->doe_mbs, index, doe_mb) {
> + if (!xa_empty(&doe_mb->feats))
> + return true;
> + }
> +
> + return false;
So in principle, doe_mb->feats should never be empty because the
discovery protocol is always supported, right? Wouldn't it then
suffice to just check for:
+ if (!xa_empty(&pdev->doe_mbs))
+ return true;
Or alternatively:
+ return !xa_empty(&pdev->doe_mbs);
Thanks,
Lukas