@@ -583,3 +583,31 @@ Description:
enclosure-specific indications "specific0" to "specific7",
hence the corresponding led class devices are unavailable if
the DSM interface is used.
+
+What: /sys/bus/pci/devices/.../doe_features
+Date: March 2025
+Contact: Linux PCI developers <linux-pci@vger.kernel.org>
+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
@@ -14,10 +14,12 @@
#include <linux/bitfield.h>
#include <linux/delay.h>
+#include <linux/device.h>
#include <linux/jiffies.h>
#include <linux/mutex.h>
#include <linux/pci.h>
#include <linux/pci-doe.h>
+#include <linux/sysfs.h>
#include <linux/workqueue.h>
#include "pci.h"
@@ -47,6 +49,7 @@
* @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 +59,10 @@ 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 +99,144 @@ 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 bool pci_doe_features_sysfs_group_visible(struct kobject *kobj)
+{
+ struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
+
+ return !xa_empty(&pdev->doe_mbs);
+}
+DEFINE_SIMPLE_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 == PCI_VENDOR_ID_PCI_SIG && type == PCI_DOE_FEATURE_DISCOVERY) {
+ /* 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,
@@ -1804,6 +1804,9 @@ 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,
};
@@ -253,6 +253,7 @@ 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) { }
@@ -456,6 +457,14 @@ static inline void pci_npem_create(struct pci_dev *dev) { }
static inline void pci_npem_remove(struct pci_dev *dev) { }
#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.
*
@@ -2662,6 +2662,9 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
WARN_ON(ret < 0);
pci_npem_create(dev);
+
+ ret = pci_doe_sysfs_init(dev);
+ WARN_ON(ret < 0);
}
struct pci_dev *pci_scan_single_device(struct pci_bus *bus, int devfn)
@@ -53,6 +53,7 @@ static void pci_destroy_dev(struct pci_dev *dev)
if (pci_dev_test_and_set_removed(dev))
return;
+ pci_doe_sysfs_teardown(dev);
pci_npem_remove(dev);
device_del(&dev->dev);