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Diffstat (limited to 'drivers/gpu/drm/xe/xe_configfs.c')
| -rw-r--r-- | drivers/gpu/drm/xe/xe_configfs.c | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/drivers/gpu/drm/xe/xe_configfs.c b/drivers/gpu/drm/xe/xe_configfs.c new file mode 100644 index 000000000000..cb9f175c89a1 --- /dev/null +++ b/drivers/gpu/drm/xe/xe_configfs.c @@ -0,0 +1,250 @@ +// 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, + }, + }, +}; + +static struct xe_config_device *configfs_find_group(struct pci_dev *pdev) +{ + struct config_item *item; + char name[64]; + + snprintf(name, sizeof(name), "%04x:%02x:%02x.%x", pci_domain_nr(pdev->bus), + pdev->bus->number, PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn)); + + mutex_lock(&xe_configfs.su_mutex); + item = config_group_find_item(&xe_configfs.su_group, name); + mutex_unlock(&xe_configfs.su_mutex); + + if (!item) + return NULL; + + return to_xe_config_device(item); +} + +/** + * xe_configfs_get_survivability_mode - get configfs survivability mode attribute + * @pdev: pci device + * + * find the configfs group that belongs to the pci device and return + * the survivability mode attribute + * + * Return: survivability mode if config group is found, false otherwise + */ +bool xe_configfs_get_survivability_mode(struct pci_dev *pdev) +{ + struct xe_config_device *dev = configfs_find_group(pdev); + bool mode; + + if (!dev) + return false; + + mode = dev->survivability_mode; + config_item_put(&dev->group.cg_item); + + return mode; +} + +/** + * xe_configfs_clear_survivability_mode - clear configfs survivability mode attribute + * @pdev: pci device + * + * find the configfs group that belongs to the pci device and clear survivability + * mode attribute + */ +void xe_configfs_clear_survivability_mode(struct pci_dev *pdev) +{ + struct xe_config_device *dev = configfs_find_group(pdev); + + if (!dev) + return; + + mutex_lock(&dev->lock); + dev->survivability_mode = 0; + mutex_unlock(&dev->lock); + + config_item_put(&dev->group.cg_item); +} + +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); +} + |