[Intel-gfx] [RFC] [PATCH 4/7] drm/i915: add i915_get_reset_status_ioctl

[Mika Kuoppala]

This ioctl returns reset status for specified context.

Returned status is context loss state with regards to
previous call to this ioctl. It can one off:

no_error : no context lost detected

guilty   : context was lost and this context was one
           submitting a batch which hung the gpu

innocent : context was lost but this context fell victim
           to some other context which submitted batch which
           hung the gpu

v2: get rid of state tracking completely and deliver only counts. Idea
    from Chris Wilson.

Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>
---
 drivers/gpu/drm/i915/i915_dma.c |    1 +
 drivers/gpu/drm/i915/i915_drv.c |   42 +++++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/i915_drv.h |    6 ++++++
 include/uapi/drm/i915_drm.h     |   19 ++++++++++++++++++
 4 files changed, 68 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 82732ee..00b6765 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1882,6 +1882,7 @@ struct drm_ioctl_desc i915_ioctls[] = {
 	DRM_IOCTL_DEF_DRV(I915_GEM_CONTEXT_CREATE, i915_gem_context_create_ioctl, DRM_UNLOCKED),
 	DRM_IOCTL_DEF_DRV(I915_GEM_CONTEXT_DESTROY, i915_gem_context_destroy_ioctl, DRM_UNLOCKED),
 	DRM_IOCTL_DEF_DRV(I915_REG_READ, i915_reg_read_ioctl, DRM_UNLOCKED),
+	DRM_IOCTL_DEF_DRV(I915_GET_RESET_STATS, i915_get_reset_stats_ioctl, DRM_UNLOCKED),
 };
 
 int i915_max_ioctl = DRM_ARRAY_SIZE(i915_ioctls);
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index d159d7a..67b023a 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -823,6 +823,9 @@ int i915_reset(struct drm_device *dev)
 
 	i915_gem_reset(dev);
 
+	/* Count unsuccessful ones */
+	dev_priv->reset_count++;
+
 	ret = -ENODEV;
 	if (get_seconds() - dev_priv->gpu_error.last_reset < 5)
 		DRM_ERROR("GPU hanging too fast, declaring wedged!\n");
@@ -1228,3 +1231,42 @@ int i915_reg_read_ioctl(struct drm_device *dev,
 
 	return 0;
 }
+
+int i915_get_reset_stats_ioctl(struct drm_device *dev,
+			       void *data, struct drm_file *file)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_ring_buffer *ring;
+	struct drm_i915_file_private *file_priv = file->driver_priv;
+	struct drm_i915_reset_stats *args = data;
+	struct i915_reset_stats *rs = NULL;
+	int ret;
+
+	ret = mutex_lock_interruptible(&dev->struct_mutex);
+	if (ret)
+		return ret;
+
+	if (args->ctx_id == 0) {
+		rs = &file_priv->reset_stats;
+		ret = 0;
+		goto out;
+	}
+
+	ring = &dev_priv->ring[RCS];
+
+	ret = i915_gem_context_get_reset_stats(ring,
+					       file,
+					       args->ctx_id,
+					       &rs);
+out:
+	if (rs && ret == 0) {
+		args->global_lost = dev_priv->reset_count;
+		args->total_lost = rs->total;
+		args->innocent_lost = rs->innocent;
+		args->guilty_lost = rs->guilty;
+	}
+
+	mutex_unlock(&dev->struct_mutex);
+
+	return ret ? -EINVAL : 0;
+}
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 42fcfb6..f43a482 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1040,6 +1040,10 @@ typedef struct drm_i915_private {
 	/* Old dri1 support infrastructure, beware the dragons ya fools entering
 	 * here! */
 	struct i915_dri1_state dri1;
+
+	/* get_reset_stats ioctl */
+	u32 reset_count;
+
 } drm_i915_private_t;
 
 /* Iterate over initialised rings */
@@ -1832,6 +1836,8 @@ extern int intel_enable_rc6(const struct drm_device *dev);
 extern bool i915_semaphore_is_enabled(struct drm_device *dev);
 int i915_reg_read_ioctl(struct drm_device *dev, void *data,
 			struct drm_file *file);
+int i915_get_reset_stats_ioctl(struct drm_device *dev, void *data,
+			       struct drm_file *file);
 
 /* overlay */
 #ifdef CONFIG_DEBUG_FS
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index 07d5941..8f4f5e2 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -198,6 +198,7 @@ typedef struct _drm_i915_sarea {
 #define DRM_I915_GEM_SET_CACHING	0x2f
 #define DRM_I915_GEM_GET_CACHING	0x30
 #define DRM_I915_REG_READ		0x31
+#define DRM_I915_GET_RESET_STATS	0x32
 
 #define DRM_IOCTL_I915_INIT		DRM_IOW( DRM_COMMAND_BASE + DRM_I915_INIT, drm_i915_init_t)
 #define DRM_IOCTL_I915_FLUSH		DRM_IO ( DRM_COMMAND_BASE + DRM_I915_FLUSH)
@@ -247,6 +248,7 @@ typedef struct _drm_i915_sarea {
 #define DRM_IOCTL_I915_GEM_CONTEXT_CREATE	DRM_IOWR (DRM_COMMAND_BASE + DRM_I915_GEM_CONTEXT_CREATE, struct drm_i915_gem_context_create)
 #define DRM_IOCTL_I915_GEM_CONTEXT_DESTROY	DRM_IOW (DRM_COMMAND_BASE + DRM_I915_GEM_CONTEXT_DESTROY, struct drm_i915_gem_context_destroy)
 #define DRM_IOCTL_I915_REG_READ			DRM_IOWR (DRM_COMMAND_BASE + DRM_I915_REG_READ, struct drm_i915_reg_read)
+#define DRM_IOCTL_I915_GET_RESET_STATS		DRM_IOWR (DRM_COMMAND_BASE + DRM_I915_GET_RESET_STATS, struct drm_i915_reset_stats)
 
 /* Allow drivers to submit batchbuffers directly to hardware, relying
  * on the security mechanisms provided by hardware.
@@ -980,4 +982,21 @@ struct drm_i915_reg_read {
 	__u64 offset;
 	__u64 val; /* Return value */
 };
+
+struct drm_i915_reset_stats {
+	__u32 ctx_id;
+	__u32 flags;
+
+	/* For all contexts */
+	__u32 global_lost;
+
+	/* For this context */
+	__u32 total_lost;
+	__u32 innocent_lost;
+	__u32 guilty_lost;
+
+	/* unknown_lost ==
+	 * total - (innocent + guilty) */
+};
+
 #endif /* _UAPI_I915_DRM_H_ */
-- 
1.7.9.5