[RFC PATCH v3 2/4] drm: Create DRM_IOCTL_GET_RESET
From: André Almeida
Date: Tue Jun 20 2023 - 20:58:51 EST
Create a new DRM ioctl operation to get the numbers of resets for a
given context. The numbers reflect just the resets that happened after
the context was created, and not since the machine was booted.
Create a debugfs interface to make easier to test the API without real
resets.
Signed-off-by: André Almeida <andrealmeid@xxxxxxxxxx>
---
drivers/gpu/drm/drm_debugfs.c | 2 ++
drivers/gpu/drm/drm_ioctl.c | 58 +++++++++++++++++++++++++++++++++++
include/drm/drm_device.h | 3 ++
include/drm/drm_drv.h | 3 ++
include/uapi/drm/drm.h | 21 +++++++++++++
include/uapi/drm/drm_mode.h | 15 +++++++++
6 files changed, 102 insertions(+)
diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c
index 4855230ba2c6..316dce60434d 100644
--- a/drivers/gpu/drm/drm_debugfs.c
+++ b/drivers/gpu/drm/drm_debugfs.c
@@ -251,6 +251,8 @@ int drm_debugfs_init(struct drm_minor *minor, int minor_id,
list_del(&entry->list);
}
+ debugfs_create_bool("drm_reset_spoof", 0644, minor->debugfs_root, &dev->reset_spoof);
+
return 0;
}
diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
index 7c9d66ee917d..23c282681ec7 100644
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -528,6 +528,63 @@ int drm_version(struct drm_device *dev, void *data,
return err;
}
+/**
+ * drm_spoof_reset - Spoof a fake reset
+ *
+ * @reset: reset struct to be spoofed
+ *
+ * Create a fake reset report for testing
+ */
+static void drm_spoof_reset(struct drm_get_reset *reset)
+{
+ reset->dev_reset_count = 1;
+ reset->ctx_reset_count = 0;
+ reset->flags = 0;
+ reset->ctx_id = 0;
+
+ DRM_INFO("[Spoofed] Reporting reset.ctx = %llu .dev = %llu\n",
+ reset->ctx_reset_count, reset->dev_reset_count);
+}
+
+/**
+ * drm_getreset - Get reset information from a DRM device
+ *
+ * @dev DRM device
+ * @data user argument, pointing to a drm_get_reset structure
+ * @filp file pointer
+ *
+ * Return zero on success or negative number on failure.
+ *
+ * Fills in the reset information in data arg.
+ */
+int drm_getreset(struct drm_device *dev, void *data,
+ struct drm_file *file_priv)
+{
+ struct drm_get_reset *reset = data;
+ int ret = 0;
+
+ if (dev->reset_spoof) {
+ drm_spoof_reset(reset);
+ return 0;
+ }
+
+ if (!dev->driver->get_reset)
+ return -ENOSYS;
+
+ if (reset->flags)
+ return -EINVAL;
+
+ ret = dev->driver->get_reset(file_priv, dev, reset);
+
+ if (!ret)
+ DRM_INFO("Reporting reset.ctx = %llu .dev = %llu\n",
+ reset->ctx_reset_count, reset->dev_reset_count);
+ else
+ DRM_WARN("%s failed with %d return\n", __func__, ret);
+
+ return ret;
+}
+
static int drm_ioctl_permit(u32 flags, struct drm_file *file_priv)
{
/* ROOT_ONLY is only for CAP_SYS_ADMIN */
@@ -716,6 +773,7 @@ static const struct drm_ioctl_desc drm_ioctls[] = {
DRM_IOCTL_DEF(DRM_IOCTL_MODE_LIST_LESSEES, drm_mode_list_lessees_ioctl, DRM_MASTER),
DRM_IOCTL_DEF(DRM_IOCTL_MODE_GET_LEASE, drm_mode_get_lease_ioctl, DRM_MASTER),
DRM_IOCTL_DEF(DRM_IOCTL_MODE_REVOKE_LEASE, drm_mode_revoke_lease_ioctl, DRM_MASTER),
+ DRM_IOCTL_DEF(DRM_IOCTL_GET_RESET, drm_getreset, DRM_RENDER_ALLOW),
};
#define DRM_CORE_IOCTL_COUNT ARRAY_SIZE(drm_ioctls)
diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h
index 7cf4afae2e79..fcd7b5d45cde 100644
--- a/include/drm/drm_device.h
+++ b/include/drm/drm_device.h
@@ -326,6 +326,9 @@ struct drm_device {
*/
struct list_head debugfs_list;
+ /* Spoof device reset for testing */
+ bool reset_spoof;
+
/* Everything below here is for legacy driver, never use! */
/* private: */
#if IS_ENABLED(CONFIG_DRM_LEGACY)
diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
index 89e2706cac56..518a9db157fb 100644
--- a/include/drm/drm_drv.h
+++ b/include/drm/drm_drv.h
@@ -401,6 +401,9 @@ struct drm_driver {
struct drm_device *dev, uint32_t handle,
uint64_t *offset);
+ int (*get_reset)(struct drm_file *file_priv,
+ struct drm_device *dev, struct drm_get_reset *reset);
+
/**
* @show_fdinfo:
*
diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
index a87bbbbca2d4..a84559aa0d77 100644
--- a/include/uapi/drm/drm.h
+++ b/include/uapi/drm/drm.h
@@ -1169,6 +1169,27 @@ extern "C" {
*/
#define DRM_IOCTL_MODE_GETFB2 DRM_IOWR(0xCE, struct drm_mode_fb_cmd2)
+/**
+ * DRM_IOCTL_GET_RESET - Get information about device resets
+ *
+ * This operation requests from the device information about resets. It should
+ * consider only resets that happens after the context is created, therefore,
+ * the counter should be zero during context creation.
+ *
+ * dev_reset_count tells how many resets have happened on this device, and
+ * ctx_reset_count tells how many of such resets were caused by this context.
+ *
+ * Flags can be used to tell if a reset is in progress, and userspace should
+ * wait until it's not in progress anymore to be able to create a new context;
+ * and to tell if the VRAM is considered lost. There's no safe way to clean this
+ * flag so if a context see this flag set, it should be like that until the end
+ * of the context.
+ */
+#define DRM_IOCTL_GET_RESET DRM_IOWR(0xCF, struct drm_get_reset)
+
+#define DRM_RESET_IN_PROGRESS 0x1
+#define DRM_RESET_VRAM_LOST 0x2
+
/*
* Device specific ioctls should only be in their respective headers
* The device specific ioctl range is from 0x40 to 0x9f.
diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h
index 43691058d28f..c3257bd1af9c 100644
--- a/include/uapi/drm/drm_mode.h
+++ b/include/uapi/drm/drm_mode.h
@@ -1308,6 +1308,21 @@ struct drm_mode_rect {
__s32 y2;
};
+/**
+ * struct drm_get_reset - Get information about a DRM device resets
+ * @ctx_id: the context id to be queried about resets
+ * @flags: flags
+ * @dev_reset_count: global counter of resets for a given DRM device
+ * @ctx_reset_count: of all the resets counted by this device, how many were
+ * caused by this context.
+ */
+struct drm_get_reset {
+ __u32 ctx_id;
+ __u32 flags;
+ __u64 dev_reset_count;
+ __u64 ctx_reset_count;
+};
+
#if defined(__cplusplus)
}
#endif
--
2.41.0