3 files changed, 55 insertions, 25 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index ea389771f917..d00761a06f05 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -352,14 +352,21 @@ struct drm_i915_file_private {
 
 	unsigned int bsd_engine;
 
-/* Client can have a maximum of 3 contexts banned before
- * it is denied of creating new contexts. As one context
- * ban needs 4 consecutive hangs, and more if there is
- * progress in between, this is a last resort stop gap measure
- * to limit the badly behaving clients access to gpu.
+/*
+ * Every context ban increments per client ban score. Also
+ * hangs in short succession increments ban score. If ban threshold
+ * is reached, client is considered banned and submitting more work
+ * will fail. This is a stop gap measure to limit the badly behaving
+ * clients access to gpu. Note that unbannable contexts never increment
+ * the client ban score.
  */
-#define I915_MAX_CLIENT_CONTEXT_BANS 3
-	atomic_t context_bans;
+#define I915_CLIENT_SCORE_HANG_FAST	1
+#define   I915_CLIENT_FAST_HANG_JIFFIES (60 * HZ)
+#define I915_CLIENT_SCORE_CONTEXT_BAN   3
+#define I915_CLIENT_SCORE_BANNED	9
+	/** ban_score: Accumulated score of all ctx bans and fast hangs. */
+	atomic_t ban_score;
+	unsigned long hang_timestamp;
 };
 
 /* Interface history:
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 8dd4d35655af..977982a987c8 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2941,32 +2941,54 @@ i915_gem_object_pwrite_gtt(struct drm_i915_gem_object *obj,
 	return 0;
 }
 
+static void i915_gem_client_mark_guilty(struct drm_i915_file_private *file_priv,
+					const struct i915_gem_context *ctx)
+{
+	unsigned int score;
+	unsigned long prev_hang;
+
+	if (i915_gem_context_is_banned(ctx))
+		score = I915_CLIENT_SCORE_CONTEXT_BAN;
+	else
+		score = 0;
+
+	prev_hang = xchg(&file_priv->hang_timestamp, jiffies);
+	if (time_before(jiffies, prev_hang + I915_CLIENT_FAST_HANG_JIFFIES))
+		score += I915_CLIENT_SCORE_HANG_FAST;
+
+	if (score) {
+		atomic_add(score, &file_priv->ban_score);
+
+		DRM_DEBUG_DRIVER("client %s: gained %u ban score, now %u\n",
+				 ctx->name, score,
+				 atomic_read(&file_priv->ban_score));
+	}
+}
+
 static void i915_gem_context_mark_guilty(struct i915_gem_context *ctx)
 {
-	bool banned;
+	unsigned int score;
+	bool banned, bannable;
 
 	atomic_inc(&ctx->guilty_count);
 
-	banned = false;
-	if (i915_gem_context_is_bannable(ctx)) {
-		unsigned int score;
+	bannable = i915_gem_context_is_bannable(ctx);
+	score = atomic_add_return(CONTEXT_SCORE_GUILTY, &ctx->ban_score);
+	banned = score >= CONTEXT_SCORE_BAN_THRESHOLD;
 
-		score = atomic_add_return(CONTEXT_SCORE_GUILTY,
-					  &ctx->ban_score);
-		banned = score >= CONTEXT_SCORE_BAN_THRESHOLD;
+	DRM_DEBUG_DRIVER("context %s: guilty %d, score %u, ban %s\n",
+			 ctx->name, atomic_read(&ctx->guilty_count),
+			 score, yesno(banned && bannable));
 
-		DRM_DEBUG_DRIVER("context %s marked guilty (score %d) banned? %s\n",
-				 ctx->name, score, yesno(banned));
-	}
-	if (!banned)
+	/* Cool contexts don't accumulate client ban score */
+	if (!bannable)
 		return;
 
-	i915_gem_context_set_banned(ctx);
-	if (!IS_ERR_OR_NULL(ctx->file_priv)) {
-		atomic_inc(&ctx->file_priv->context_bans);
-		DRM_DEBUG_DRIVER("client %s has had %d context banned\n",
-				 ctx->name, atomic_read(&ctx->file_priv->context_bans));
-	}
+	if (banned)
+		i915_gem_context_set_banned(ctx);
+
+	if (!IS_ERR_OR_NULL(ctx->file_priv))
+		i915_gem_client_mark_guilty(ctx->file_priv, ctx);
 }
 
 static void i915_gem_context_mark_innocent(struct i915_gem_context *ctx)
@@ -5820,6 +5842,7 @@ int i915_gem_open(struct drm_i915_private *i915, struct drm_file *file)
 	INIT_LIST_HEAD(&file_priv->mm.request_list);
 
 	file_priv->bsd_engine = -1;
+	file_priv->hang_timestamp = jiffies;
 
 	ret = i915_gem_context_open(i915, file);
 	if (ret)
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index ef6ea4bcd773..ccf463ab6562 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -708,7 +708,7 @@ int i915_gem_switch_to_kernel_context(struct drm_i915_private *i915)
 
 static bool client_is_banned(struct drm_i915_file_private *file_priv)
 {
-	return atomic_read(&file_priv->context_bans) > I915_MAX_CLIENT_CONTEXT_BANS;
+	return atomic_read(&file_priv->ban_score) >= I915_CLIENT_SCORE_BANNED;
 }
 
 int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,