drm/xe: Add configfs to enable survivability mode

Registers a configfs subsystem called 'xe' that creates a
directory in the mounted configfs directory (/sys/kernel/config)
Userspace can then create the device that has to be configured
under the xe directory

	mkdir /sys/kernel/config/xe/0000:03:00.0

The device created will have the following attributes to be
configured

	/sys/kernel/config/xe/
		.. 0000:03:00.0/
			... survivability_mode

v2: fix kernel-doc
    fix return value (Lucas)

v3: fix kernel-doc (Lucas)

Signed-off-by: Riana Tauro <riana.tauro@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20250407051414.1651616-2-riana.tauro@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>

diff --git a/Documentation/gpu/xe/index.rst b/Documentation/gpu/xe/index.rst
index 92cfb25e64d3279c724d4657d5e380a9aa61a1f3..b2369561f24e18826b154adf3499c4b8a4594e2b 100644 (file)
--- a/Documentation/gpu/xe/index.rst
+++ b/Documentation/gpu/xe/index.rst
@@ -25,3 +25,4 @@ DG2, etc is provided to prototype the driver.
    xe_debugging
    xe_devcoredump
    xe-drm-usage-stats.rst
+   xe_configfs

diff --git a/Documentation/gpu/xe/xe_configfs.rst b/Documentation/gpu/xe/xe_configfs.rst
new file mode 100644 (file)
index 0000000..9b9d941
--- /dev/null
+++ b/Documentation/gpu/xe/xe_configfs.rst
@@ -0,0 +1,10 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+.. _xe_configfs:
+
+============
+Xe Configfs
+============
+
+.. kernel-doc:: drivers/gpu/drm/xe/xe_configfs.c
+   :doc: Xe Configfs

diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
index e4fec90bab551fbcbf7ba93a4ef1b2eff6b995f5..c1493ef2c12b66f2e37ee79e3360f3405f2c4d96 100644 (file)
--- a/drivers/gpu/drm/xe/Makefile
+++ b/drivers/gpu/drm/xe/Makefile
@@ -131,6 +131,7 @@ xe-$(CONFIG_DRM_XE_GPUSVM) += xe_svm.o
 xe-$(CONFIG_HWMON) += xe_hwmon.o
 
 xe-$(CONFIG_PERF_EVENTS) += xe_pmu.o
+xe-$(CONFIG_CONFIGFS_FS) += xe_configfs.o
 
 # graphics virtualization (SR-IOV) support
 xe-y += \

diff --git a/drivers/gpu/drm/xe/xe_configfs.c b/drivers/gpu/drm/xe/xe_configfs.c
new file mode 100644 (file)
index 0000000..48a9f42
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_configfs.c
@@ -0,0 +1,188 @@
+// 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
+ *
+ * Overview
+ * =========
+ *
+ * Configfs is a filesystem-based manager of kernel objects. XE KMD registers a
+ * configfs subsystem called ``'xe'`` that creates a directory in the mounted configfs directory
+ * The user can create devices under this directory and configure them as necessary
+ * See Documentation/filesystems/configfs.rst for more information about how configfs works.
+ *
+ * Create devices
+ * ===============
+ *
+ * In order to create a device, the user has to create a directory inside ``'xe'``::
+ *
+ *     mkdir /sys/kernel/config/xe/0000:03:00.0/
+ *
+ * Every device created is populated by the driver with entries that can be
+ * used to configure it::
+ *
+ *     /sys/kernel/config/xe/
+ *             .. 0000:03:00.0/
+ *                     ... survivability_mode
+ *
+ * Configure Attributes
+ * ====================
+ *
+ * Survivability mode:
+ * -------------------
+ *
+ * Enable survivability mode on supported cards. This setting only takes
+ * effect when probing the device. Example to enable it::
+ *
+ *     # echo 1 > /sys/kernel/config/xe/0000:03:00.0/survivability_mode
+ *     # echo 0000:03:00.0 > /sys/bus/pci/drivers/xe/bind  (Enters survivability mode if supported)
+ *
+ * Remove devices
+ * ==============
+ *
+ * The created device directories can be removed using ``rmdir``::
+ *
+ *     rmdir /sys/kernel/config/xe/0000:03:00.0/
+ */
+
+struct xe_config_device {
+       struct config_group group;
+
+       bool survivability_mode;
+
+       /* 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;
+
+       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;
+       }
+
+       return 0;
+}
+
+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 (file)
index 0000000..5532320
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_configfs.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2025 Intel Corporation
+ */
+#ifndef _XE_CONFIGFS_H_
+#define _XE_CONFIGFS_H_
+
+#if IS_ENABLED(CONFIG_CONFIGFS_FS)
+int xe_configfs_init(void);
+void xe_configfs_exit(void);
+#else
+static inline int xe_configfs_init(void) { return 0; };
+static inline void xe_configfs_exit(void) {};
+#endif
+
+#endif

diff --git a/drivers/gpu/drm/xe/xe_module.c b/drivers/gpu/drm/xe/xe_module.c
index 9f4632e39a1ad5776557633af06749c0c5606e78..be8603b16ff3fbf7cfc5de6daa627c7a446bafde 100644 (file)
--- 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"
@@ -88,6 +89,10 @@ 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,