[0034/1094] drm/i915: Piggy back hangstats off of contexts

Commit Message

Dheeraj Jamwal Oct. 21, 2014, 10:43 a.m. UTC

From: Ben Widawsky <[e-mail]>

To simplify the codepaths somewhat, we can simply always create a
context. Contexts already keep hangstat information. This prevents us
from having to differentiate at other parts in the code.

There is allocation overhead, but it should not be measurable.

Signed-off-by: Ben Widawsky <[e-mail]>
Signed-off-by: Daniel Vetter <[e-mail]>
(cherry picked from commit c482972a086e03e6a6d27e4f7af2d868bf659648)

Signed-off-by: Dheeraj Jamwal <[e-mail]>
---
 drivers/gpu/drm/i915/i915_drv.h         |    7 ++++---
 drivers/gpu/drm/i915/i915_gem.c         |    2 +-
 drivers/gpu/drm/i915/i915_gem_context.c |   27 +++++++++++++++------------
 3 files changed, 20 insertions(+), 16 deletions(-)

Patch

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 572464c..c243e6b 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1767,7 +1767,6 @@  struct drm_i915_file_private {
 	} mm;
 	struct idr context_idr;
 
-	struct i915_ctx_hang_stats hang_stats;
 	struct i915_hw_context *private_default_ctx;
 	atomic_t rps_wait_boost;
 };
@@ -2262,12 +2261,14 @@  int i915_switch_context(struct intel_ring_buffer *ring,
 void i915_gem_context_free(struct kref *ctx_ref);
 static inline void i915_gem_context_reference(struct i915_hw_context *ctx)
 {
-	kref_get(&ctx->ref);
+	if (ctx->obj && HAS_HW_CONTEXTS(ctx->obj->base.dev))
+		kref_get(&ctx->ref);
 }
 
 static inline void i915_gem_context_unreference(struct i915_hw_context *ctx)
 {
-	kref_put(&ctx->ref, i915_gem_context_free);
+	if (ctx->obj && HAS_HW_CONTEXTS(ctx->obj->base.dev))
+		kref_put(&ctx->ref, i915_gem_context_free);
 }
 
 struct i915_ctx_hang_stats * __must_check
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index aee218a..428c260 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2350,7 +2350,7 @@  static void i915_set_reset_status(struct intel_ring_buffer *ring,
 	if (request->ctx && request->ctx->id != DEFAULT_CONTEXT_ID)
 		hs = &request->ctx->hang_stats;
 	else if (request->file_priv)
-		hs = &request->file_priv->hang_stats;
+		hs = &request->file_priv->private_default_ctx->hang_stats;
 
 	if (hs) {
 		if (guilty) {
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 6d7cfc2..4446710 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -490,15 +490,8 @@  i915_gem_context_get_hang_stats(struct drm_device *dev,
 				struct drm_file *file,
 				u32 id)
 {
-	struct drm_i915_file_private *file_priv = file->driver_priv;
 	struct i915_hw_context *ctx;
 
-	if (id == DEFAULT_CONTEXT_ID)
-		return &file_priv->hang_stats;
-
-	if (!HAS_HW_CONTEXTS(dev))
-		return ERR_PTR(-ENOENT);
-
 	ctx = i915_gem_context_get(file->driver_priv, id);
 	if (ctx == NULL)
 		return ERR_PTR(-ENOENT);
@@ -509,9 +502,15 @@  i915_gem_context_get_hang_stats(struct drm_device *dev,
 int i915_gem_context_open(struct drm_device *dev, struct drm_file *file)
 {
 	struct drm_i915_file_private *file_priv = file->driver_priv;
+	struct drm_i915_private *dev_priv = dev->dev_private;
 
-	if (!HAS_HW_CONTEXTS(dev))
+	if (!HAS_HW_CONTEXTS(dev)) {
+		/* Cheat for hang stats */
+		file_priv->private_default_ctx =
+			kzalloc(sizeof(struct i915_hw_context), GFP_KERNEL);
+		file_priv->private_default_ctx->vm = &dev_priv->gtt.base;
 		return 0;
+	}
 
 	idr_init(&file_priv->context_idr);
 
@@ -532,8 +531,11 @@  void i915_gem_context_close(struct drm_device *dev, struct drm_file *file)
 {
 	struct drm_i915_file_private *file_priv = file->driver_priv;
 
-	if (!HAS_HW_CONTEXTS(dev))
+	if (!HAS_HW_CONTEXTS(dev)) {
+		kfree(file_priv->private_default_ctx);
 		return;
+        }
+
 	idr_for_each(&file_priv->context_idr, context_idr_cleanup, NULL);
 	i915_gem_context_unreference(file_priv->private_default_ctx);
 	idr_destroy(&file_priv->context_idr);
@@ -721,9 +723,6 @@  int i915_switch_context(struct intel_ring_buffer *ring,
 
 	WARN_ON(!mutex_is_locked(&dev_priv->dev->struct_mutex));
 
-	if (!HAS_HW_CONTEXTS(ring->dev))
-		return 0;
-
 	if (file == NULL)
 		to = ring->default_context;
 	else
@@ -732,6 +731,10 @@  int i915_switch_context(struct intel_ring_buffer *ring,
 	if (to == NULL)
 		return -ENOENT;
 
+	/* We have the fake context, but don't supports switching. */
+	if (!HAS_HW_CONTEXTS(ring->dev))
+		return 0;
+
 	return do_switch(ring, to);
 }