[Intel-gfx] [PATCH 14/16] drm/i915: refuse to submit more batchbuffers from guilty context

[Mika Kuoppala]

If context has recently submitted a faulty batchbuffers guilty of
gpu hang and decides to keep submitting more crap, ban it permanently.

v2: Store guilty ban status bool in gpu_error instead of pointers
    that might become danling before hang is declared.

Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.c            |    6 +++++-
 drivers/gpu/drm/i915/i915_drv.h            |    9 +++++++++
 drivers/gpu/drm/i915/i915_gem.c            |   14 ++++++++++++--
 drivers/gpu/drm/i915/i915_gem_execbuffer.c |   13 +++++++++++++
 4 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index bddb9a5..ae689b4 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -885,10 +885,14 @@ int i915_reset(struct drm_device *dev)
 
 	mutex_lock(&dev->struct_mutex);
 
+	/* i915_gem_reset() will set this */
+	dev_priv->gpu_error.ctx_banned = false;
+
 	i915_gem_reset(dev);
 
 	ret = -ENODEV;
-	if (get_seconds() - dev_priv->gpu_error.last_reset < 5)
+	if (!dev_priv->gpu_error.ctx_banned &&
+	    get_seconds() - dev_priv->gpu_error.last_reset < 5)
 		DRM_ERROR("GPU hanging too fast, declaring wedged!\n");
 	else
 		ret = intel_gpu_reset(dev);
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 3b393ed..1945224 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -459,6 +459,12 @@ struct i915_ctx_hang_stats {
 
 	/* This context had batch active when hang was declared */
 	unsigned batch_active;
+
+	/* Time when this context was last blamed for a GPU reset */
+	unsigned long batch_active_reset_ts;
+
+	/* This context is banned to submit more work */
+	bool banned;
 };
 
 /* This must match up with the value previously used for execbuf2.rsvd1. */
@@ -835,6 +841,9 @@ struct i915_gpu_error {
 
 	unsigned long last_reset;
 
+	/* During reset handling, guilty context found and banned */
+	bool ctx_banned;
+
 	/**
 	 * State variable and reset counter controlling the reset flow
 	 *
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 0e87765..134528a 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2147,6 +2147,7 @@ static void i915_set_reset_status(struct intel_ring_buffer *ring,
 				  struct drm_i915_gem_request *request,
 				  u32 acthd)
 {
+	struct drm_i915_private *dev_priv = ring->dev->dev_private;
 	struct i915_ctx_hang_stats *hs = NULL;
 	bool inside, guilty;
 
@@ -2175,10 +2176,19 @@ static void i915_set_reset_status(struct intel_ring_buffer *ring,
 		hs = &request->file_priv->hang_stats;
 
 	if (hs) {
-		if (guilty)
+		if (guilty) {
+			if (!hs->banned &&
+			    get_seconds() - hs->batch_active_reset_ts < 5) {
+				hs->banned = true;
+				DRM_ERROR("context hanging too fast, "
+					  "declaring banned\n");
+				dev_priv->gpu_error.ctx_banned = true;
+			}
 			hs->batch_active++;
-		else
+			hs->batch_active_reset_ts = get_seconds();
+		} else {
 			hs->batch_pending++;
+		}
 	}
 }
 
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index bd1750a..f1b1ea9 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -844,6 +844,7 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
 	struct drm_clip_rect *cliprects = NULL;
 	struct intel_ring_buffer *ring;
 	struct i915_hw_context *ctx;
+	struct i915_ctx_hang_stats *hs;
 	u32 ctx_id = i915_execbuffer2_get_context_id(*args);
 	u32 exec_start, exec_len;
 	u32 mask, flags;
@@ -1026,6 +1027,18 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
 	if (ret)
 		goto err;
 
+	hs = i915_gem_context_get_hang_stats(&dev_priv->ring[RCS],
+					     file, ctx_id);
+	if (IS_ERR(hs)) {
+		ret = PTR_ERR(hs);
+		goto err;
+	}
+
+	if (hs->banned) {
+		ret = -EIO;
+		goto err;
+	}
+
 	ctx = i915_switch_context(ring, file, ctx_id);
 	if (IS_ERR(ctx)) {
 		ret = PTR_ERR(ctx);
-- 
1.7.9.5