[PATCH 1/2] drm/xe: Add configfs to enable survivability mode
Riana Tauro
riana.tauro at intel.com
Thu Mar 27 06:42:01 UTC 2025
Registers a configfs subsystem called 'xe' to userspace. The user can
use this to modify exposed attributes for a device.
Attribute exposed:
/config/xe/<device>/survivability_mode : Enables survivability mode
The attributes can be modified by creating the device directory under the
configfs directory
mount -t configfs none /config
mkdir /config/xe/0000:03:00.0
echo 0000:03:00.0 > /sys/bus/pci/drivers/xe/unbind
echo 1 > /config/xe/0000:03:00.0/survivability_mode
echo 0000:03:00.0 > /sys/bus/pci/drivers/xe/bind
Signed-off-by: Riana Tauro <riana.tauro at intel.com>
---
drivers/gpu/drm/xe/Makefile | 1 +
drivers/gpu/drm/xe/xe_configfs.c | 174 +++++++++++++++++++++++++++++++
drivers/gpu/drm/xe/xe_configfs.h | 11 ++
drivers/gpu/drm/xe/xe_module.c | 5 +
4 files changed, 191 insertions(+)
create mode 100644 drivers/gpu/drm/xe/xe_configfs.c
create mode 100644 drivers/gpu/drm/xe/xe_configfs.h
diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
index cd464fe26eb8..190176c2e10d 100644
--- a/drivers/gpu/drm/xe/Makefile
+++ b/drivers/gpu/drm/xe/Makefile
@@ -28,6 +28,7 @@ $(obj)/generated/%_wa_oob.c $(obj)/generated/%_wa_oob.h: $(obj)/xe_gen_wa_oob \
xe-y += xe_bb.o \
xe_bo.o \
xe_bo_evict.o \
+ xe_configfs.o \
xe_devcoredump.o \
xe_device.o \
xe_device_sysfs.o \
diff --git a/drivers/gpu/drm/xe/xe_configfs.c b/drivers/gpu/drm/xe/xe_configfs.c
new file mode 100644
index 000000000000..59e1bc4c5f76
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_configfs.c
@@ -0,0 +1,174 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2025 Intel Corporation
+ */
+
+#include <linux/configfs.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+
+#include "xe_configfs.h"
+#include "xe_module.h"
+
+/**
+ * DOC: XE Configfs Support
+ *
+ * Overview
+ * =========
+ *
+ * Configfs is a filesystem-based manager of kernel objects. XE KMD registers a
+ * configfs subsystem called 'xe' that allows user to configure various attributes
+ * See Documentation/filesystems/configfs.rst for more information about how configfs works.
+ *
+ * Create devices
+ * ===============
+ *
+ * To use configfs exposed by Xe, mount the configfs directory and create the device directory
+ *
+ * $ mount -t configfs none /config
+ * $ mkdir /config/xe/0000:03:00.0
+ *
+ * Configure Attributes
+ * ====================
+ *
+ * /config/xe/<device>/survivability mode : Enables survivability mode if supported by device
+ *
+ * Unbind : echo 0000:03:00.0 > /sys/bus/pci/drivers/xe/unbind
+ * Enable survivability mode : echo 1 > /config/xe/0000:03:00.0/survivability_mode
+ * Bind : echo 0000:03:00.0 > /sys/bus/pci/drivers/xe/bind
+ *
+ * The device enters survivability mode if supported
+ *
+ */
+
+struct xe_config_device {
+ struct config_group group;
+
+ /** @survivability_mode: enables survivability mode when set */
+ bool survivability_mode;
+
+ /** @lock: protects attributes */
+ struct mutex lock;
+};
+
+static struct xe_config_device *to_xe_config_device(struct config_item *item)
+{
+ return container_of(to_config_group(item), struct xe_config_device, group);
+}
+
+static ssize_t survivability_mode_show(struct config_item *item, char *page)
+{
+ struct xe_config_device *dev = to_xe_config_device(item);
+
+ return sprintf(page, "%d\n", dev->survivability_mode);
+}
+
+static ssize_t survivability_mode_store(struct config_item *item, const char *page, size_t len)
+{
+ struct xe_config_device *dev = to_xe_config_device(item);
+ bool survivability_mode;
+ int ret;
+
+ ret = kstrtobool(page, &survivability_mode);
+ if (ret)
+ return ret;
+
+ mutex_lock(&dev->lock);
+ dev->survivability_mode = survivability_mode;
+ mutex_unlock(&dev->lock);
+
+ return len;
+}
+
+CONFIGFS_ATTR(, survivability_mode);
+
+static struct configfs_attribute *xe_config_device_attrs[] = {
+ &attr_survivability_mode,
+ NULL,
+};
+
+static void xe_config_device_release(struct config_item *item)
+{
+ struct xe_config_device *dev = to_xe_config_device(item);
+
+ mutex_destroy(&dev->lock);
+ kfree(dev);
+}
+
+static struct configfs_item_operations xe_config_device_ops = {
+ .release = xe_config_device_release,
+};
+
+static const struct config_item_type xe_config_device_type = {
+ .ct_item_ops = &xe_config_device_ops,
+ .ct_attrs = xe_config_device_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+static struct config_group *xe_config_make_device_group(struct config_group *group,
+ const char *name)
+{
+ unsigned int domain, bus, slot, function;
+ struct xe_config_device *dev;
+ struct pci_dev *pdev;
+ int ret;
+
+ ret = sscanf(name, "%04x:%02x:%02x.%x", &domain, &bus, &slot, &function);
+ if (ret != 4)
+ return ERR_PTR(-EINVAL);
+
+ pdev = pci_get_domain_bus_and_slot(domain, bus, PCI_DEVFN(slot, function));
+ if (!pdev)
+ return ERR_PTR(-EINVAL);
+
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ return ERR_PTR(-ENOMEM);
+
+ config_group_init_type_name(&dev->group, name, &xe_config_device_type);
+
+ mutex_init(&dev->lock);
+
+ return &dev->group;
+}
+
+static struct configfs_group_operations xe_config_device_group_ops = {
+ .make_group = xe_config_make_device_group,
+};
+
+static const struct config_item_type xe_configfs_type = {
+ .ct_group_ops = &xe_config_device_group_ops,
+ .ct_owner = THIS_MODULE,
+};
+
+static struct configfs_subsystem xe_configfs = {
+ .su_group = {
+ .cg_item = {
+ .ci_namebuf = "xe",
+ .ci_type = &xe_configfs_type,
+ },
+ },
+};
+
+int __init xe_configfs_init(void)
+{
+ struct config_group *root = &xe_configfs.su_group;
+ int ret = 0;
+
+ config_group_init(root);
+ mutex_init(&xe_configfs.su_mutex);
+ ret = configfs_register_subsystem(&xe_configfs);
+ if (ret) {
+ pr_err("Error %d while registering %s subsystem\n",
+ ret, root->cg_item.ci_namebuf);
+ }
+
+ return ret;
+}
+
+void __exit xe_configfs_exit(void)
+{
+ configfs_unregister_subsystem(&xe_configfs);
+}
+
diff --git a/drivers/gpu/drm/xe/xe_configfs.h b/drivers/gpu/drm/xe/xe_configfs.h
new file mode 100644
index 000000000000..2c30be9a2c7e
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_configfs.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2025 Intel Corporation
+ */
+#ifndef _XE_CONFIGFS_H_
+#define _XE_CONFIGFS_H_
+
+int xe_configfs_init(void);
+void xe_configfs_exit(void);
+
+#endif
diff --git a/drivers/gpu/drm/xe/xe_module.c b/drivers/gpu/drm/xe/xe_module.c
index 475acdba2b55..15b3cf22193c 100644
--- a/drivers/gpu/drm/xe/xe_module.c
+++ b/drivers/gpu/drm/xe/xe_module.c
@@ -11,6 +11,7 @@
#include <drm/drm_module.h>
#include "xe_drv.h"
+#include "xe_configfs.h"
#include "xe_hw_fence.h"
#include "xe_pci.h"
#include "xe_pm.h"
@@ -91,6 +92,10 @@ static const struct init_funcs init_funcs[] = {
{
.init = xe_check_nomodeset,
},
+ {
+ .init = xe_configfs_init,
+ .exit = xe_configfs_exit,
+ },
{
.init = xe_hw_fence_module_init,
.exit = xe_hw_fence_module_exit,
--
2.47.1
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