drm/amdgpu: add and implement the GPU reset status query

Signed-off-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu.h

@@ -1040,7 +1040,7 @@ struct amdgpu_vm_manager {
 
 struct amdgpu_ctx_state {
 	uint64_t flags;
-	uint64_t hangs;
+	uint32_t hangs;
 };
 
 struct amdgpu_ctx {
@@ -1049,6 +1049,7 @@ struct amdgpu_ctx {
 	struct amdgpu_fpriv *fpriv;
 	struct amdgpu_ctx_state state;
 	uint32_t id;
+	unsigned reset_counter;
 };
 
 struct amdgpu_ctx_mgr {
@@ -1897,8 +1898,6 @@ int amdgpu_ctx_alloc(struct amdgpu_device *adev,struct amdgpu_fpriv *fpriv,
 							uint32_t *id,uint32_t flags);
 int amdgpu_ctx_free(struct amdgpu_device *adev, struct amdgpu_fpriv *fpriv,
 						  uint32_t id);
-int amdgpu_ctx_query(struct amdgpu_device *adev, struct amdgpu_fpriv *fpriv,
-							uint32_t id,struct amdgpu_ctx_state *state);
 
 void amdgpu_ctx_fini(struct amdgpu_fpriv *fpriv);
 struct amdgpu_ctx *amdgpu_ctx_get(struct amdgpu_fpriv *fpriv, uint32_t id);
@@ -2006,6 +2005,7 @@ struct amdgpu_device {
 	atomic64_t			vram_vis_usage;
 	atomic64_t			gtt_usage;
 	atomic64_t			num_bytes_moved;
+	atomic_t			gpu_reset_counter;
 
 	/* display */
 	struct amdgpu_mode_info		mode_info;

drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c

@@ -81,21 +81,36 @@ int amdgpu_ctx_free(struct amdgpu_device *adev, struct amdgpu_fpriv *fpriv, uint
 	return -EINVAL;
 }
 
-int amdgpu_ctx_query(struct amdgpu_device *adev, struct amdgpu_fpriv *fpriv, uint32_t id, struct amdgpu_ctx_state *state)
+static int amdgpu_ctx_query(struct amdgpu_device *adev,
+			    struct amdgpu_fpriv *fpriv, uint32_t id,
+			    union drm_amdgpu_ctx_out *out)
 {
 	struct amdgpu_ctx *ctx;
 	struct amdgpu_ctx_mgr *mgr = &fpriv->ctx_mgr;
+	unsigned reset_counter;
 
 	mutex_lock(&mgr->lock);
 	ctx = idr_find(&mgr->ctx_handles, id);
-	if (ctx) {
-		/* state should alter with CS activity */
-		*state = ctx->state;
+	if (!ctx) {
 		mutex_unlock(&mgr->lock);
-		return 0;
+		return -EINVAL;
 	}
+
+	/* TODO: these two are always zero */
+	out->state.flags = ctx->state.flags;
+	out->state.hangs = ctx->state.hangs;
+
+	/* determine if a GPU reset has occured since the last call */
+	reset_counter = atomic_read(&adev->gpu_reset_counter);
+	/* TODO: this should ideally return NO, GUILTY, or INNOCENT. */
+	if (ctx->reset_counter == reset_counter)
+		out->state.reset_status = AMDGPU_CTX_NO_RESET;
+	else
+		out->state.reset_status = AMDGPU_CTX_UNKNOWN_RESET;
+	ctx->reset_counter = reset_counter;
+
 	mutex_unlock(&mgr->lock);
-	return -EINVAL;
+	return 0;
 }
 
 void amdgpu_ctx_fini(struct amdgpu_fpriv *fpriv)
@@ -120,7 +135,6 @@ int amdgpu_ctx_ioctl(struct drm_device *dev, void *data,
 	int r;
 	uint32_t id;
 	uint32_t flags;
-	struct amdgpu_ctx_state state;
 
 	union drm_amdgpu_ctx *args = data;
 	struct amdgpu_device *adev = dev->dev_private;
@@ -139,11 +153,7 @@ int amdgpu_ctx_ioctl(struct drm_device *dev, void *data,
 			r = amdgpu_ctx_free(adev, fpriv, id);
 			break;
 		case AMDGPU_CTX_OP_QUERY_STATE:
-			r = amdgpu_ctx_query(adev, fpriv, id, &state);
-			if (r == 0) {
-				args->out.state.flags = state.flags;
-				args->out.state.hangs = state.hangs;
-			}
+			r = amdgpu_ctx_query(adev, fpriv, id, &args->out);
 			break;
 		default:
 			return -EINVAL;

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c

@@ -1781,6 +1781,7 @@ int amdgpu_gpu_reset(struct amdgpu_device *adev)
 	}
 
 	adev->needs_reset = false;
+	atomic_inc(&adev->gpu_reset_counter);
 
 	/* block TTM */
 	resched = ttm_bo_lock_delayed_workqueue(&adev->mman.bdev);

include/uapi/drm/amdgpu_drm.h

@@ -149,6 +149,12 @@ union drm_amdgpu_bo_list {
 
 #define AMDGPU_CTX_OP_STATE_RUNNING	1
 
+/* GPU reset status */
+#define AMDGPU_CTX_NO_RESET		0
+#define AMDGPU_CTX_GUILTY_RESET		1 /* this the context caused it */
+#define AMDGPU_CTX_INNOCENT_RESET	2 /* some other context caused it */
+#define AMDGPU_CTX_UNKNOWN_RESET	3 /* unknown cause */
+
 struct drm_amdgpu_ctx_in {
 	uint32_t	op;
 	uint32_t	flags;
@@ -164,7 +170,10 @@ union drm_amdgpu_ctx_out {
 
 		struct {
 			uint64_t	flags;
-			uint64_t	hangs;
+			/** Number of resets caused by this context so far. */
+			uint32_t	hangs;
+			/** Reset status since the last call of the ioctl. */
+			uint32_t	reset_status;
 		} state;
 };