diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 3cf440eee8a2..17fc5dc708f4 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -26,6 +26,7 @@ * DEALINGS IN THE SOFTWARE. */ +#include #include #include #include @@ -34,6 +35,7 @@ #include #include #include +#include #include #include @@ -498,6 +500,72 @@ void drm_dev_unplug(struct drm_device *dev) } EXPORT_SYMBOL(drm_dev_unplug); +/* + * Available recovery methods for wedged device. To be sent along with device + * wedged uevent. + */ +static const char *drm_get_wedge_recovery(unsigned int opt) +{ + switch (BIT(opt)) { + case DRM_WEDGE_RECOVERY_NONE: + return "none"; + case DRM_WEDGE_RECOVERY_REBIND: + return "rebind"; + case DRM_WEDGE_RECOVERY_BUS_RESET: + return "bus-reset"; + default: + return NULL; + } +} + +/** + * drm_dev_wedged_event - generate a device wedged uevent + * @dev: DRM device + * @method: method(s) to be used for recovery + * + * This generates a device wedged uevent for the DRM device specified by @dev. + * Recovery @method\(s) of choice will be sent in the uevent environment as + * ``WEDGED=[,..,]`` in order of less to more side-effects. + * If caller is unsure about recovery or @method is unknown (0), + * ``WEDGED=unknown`` will be sent instead. + * + * Refer to "Device Wedging" chapter in Documentation/gpu/drm-uapi.rst for more + * details. + * + * Returns: 0 on success, negative error code otherwise. + */ +int drm_dev_wedged_event(struct drm_device *dev, unsigned long method) +{ + const char *recovery = NULL; + unsigned int len, opt; + /* Event string length up to 28+ characters with available methods */ + char event_string[32]; + char *envp[] = { event_string, NULL }; + + len = scnprintf(event_string, sizeof(event_string), "%s", "WEDGED="); + + for_each_set_bit(opt, &method, BITS_PER_TYPE(method)) { + recovery = drm_get_wedge_recovery(opt); + if (drm_WARN_ONCE(dev, !recovery, "invalid recovery method %u\n", opt)) + break; + + len += scnprintf(event_string + len, sizeof(event_string), "%s,", recovery); + } + + if (recovery) + /* Get rid of trailing comma */ + event_string[len - 1] = '\0'; + else + /* Caller is unsure about recovery, do the best we can at this point. */ + snprintf(event_string, sizeof(event_string), "%s", "WEDGED=unknown"); + + drm_info(dev, "device wedged, %s\n", method == DRM_WEDGE_RECOVERY_NONE ? + "but recovered through reset" : "needs recovery"); + + return kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp); +} +EXPORT_SYMBOL(drm_dev_wedged_event); + /* * DRM internal mount * We want to be able to allocate our own "struct address_space" to control diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h index c91f87b5242d..6ea54a578cda 100644 --- a/include/drm/drm_device.h +++ b/include/drm/drm_device.h @@ -21,6 +21,14 @@ struct inode; struct pci_dev; struct pci_controller; +/* + * Recovery methods for wedged device in order of less to more side-effects. + * To be used with drm_dev_wedged_event() as recovery @method. Callers can + * use any one, multiple (or'd) or none depending on their needs. + */ +#define DRM_WEDGE_RECOVERY_NONE BIT(0) /* optional telemetry collection */ +#define DRM_WEDGE_RECOVERY_REBIND BIT(1) /* unbind + bind driver */ +#define DRM_WEDGE_RECOVERY_BUS_RESET BIT(2) /* unbind + reset bus device + bind */ /** * enum switch_power_state - power state of drm device diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h index 9952b846c170..a43d707b5f36 100644 --- a/include/drm/drm_drv.h +++ b/include/drm/drm_drv.h @@ -482,6 +482,7 @@ void drm_put_dev(struct drm_device *dev); bool drm_dev_enter(struct drm_device *dev, int *idx); void drm_dev_exit(int idx); void drm_dev_unplug(struct drm_device *dev); +int drm_dev_wedged_event(struct drm_device *dev, unsigned long method); /** * drm_dev_is_unplugged - is a DRM device unplugged