[Intel-gfx] [PATCH] drm/i915: Fix up the vma aliasing ppgtt binding

Daniel Vetter daniel.vetter at ffwll.ch
Mon Apr 20 09:04:05 PDT 2015


Currently we have the problem that the decision whether ptes need to
be (re)written is splattered all over the codebase. Move all that into
i915_vma_bind. This needs a few changes:
- Just reuse the PIN_* flags for i915_vma_bind and do the conversion
  to vma->bound in there to avoid duplicating the conversion code all
  over.
- We need to make binding for EXECBUF (i.e. pick aliasing ppgtt if
  around) explicit, add PIN_USER for that.
- Two callers want to update ptes, give them a PIN_UPDATE for that.

Of course we still want to avoid double-binding, but that should be
taken care of:
- A ppgtt vma will only ever see PIN_USER, so no issue with
  double-binding.
- A ggtt vma with aliasing ppgtt needs both types of binding, and we
  track that properly now.
- A ggtt vma without aliasing ppgtt could be bound twice. In the
  lower-level ->bind_vma functions hence unconditionally set
  GLOBAL_BIND when writing the ggtt ptes.

There's still a bit room for cleanup, but that's for follow-up
patches.

v2: Fixup fumbles.

v3: s/PIN_EXECBUF/PIN_USER/ for clearer meaning, suggested by Chris.

Cc: Chris Wilson <chris at chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h            | 11 +++--
 drivers/gpu/drm/i915/i915_gem.c            | 11 ++---
 drivers/gpu/drm/i915/i915_gem_execbuffer.c |  7 ++--
 drivers/gpu/drm/i915/i915_gem_gtt.c        | 65 ++++++++++++------------------
 4 files changed, 40 insertions(+), 54 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 47be4a57e6a9..80afbe3ad669 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2640,10 +2640,13 @@ void i915_init_vm(struct drm_i915_private *dev_priv,
 void i915_gem_free_object(struct drm_gem_object *obj);
 void i915_gem_vma_destroy(struct i915_vma *vma);
 
-#define PIN_MAPPABLE 0x1
-#define PIN_NONBLOCK 0x2
-#define PIN_GLOBAL 0x4
-#define PIN_OFFSET_BIAS 0x8
+/* Flags used by pin/bind&friends. */
+#define PIN_MAPPABLE	(1<<0)
+#define PIN_NONBLOCK	(1<<1)
+#define PIN_GLOBAL	(1<<2)
+#define PIN_OFFSET_BIAS	(1<<3)
+#define PIN_USER	(1<<4)
+#define PIN_UPDATE	(1<<5)
 #define PIN_OFFSET_MASK (~4095)
 int __must_check
 i915_gem_object_pin(struct drm_i915_gem_object *obj,
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 10e873c8957f..047629b08697 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3557,8 +3557,7 @@ search_free:
 		goto err_remove_node;
 
 	trace_i915_vma_bind(vma, flags);
-	ret = i915_vma_bind(vma, obj->cache_level,
-			    flags & PIN_GLOBAL ? GLOBAL_BIND : 0);
+	ret = i915_vma_bind(vma, obj->cache_level, flags);
 	if (ret)
 		goto err_finish_gtt;
 
@@ -3784,7 +3783,7 @@ int i915_gem_object_set_cache_level(struct drm_i915_gem_object *obj,
 		list_for_each_entry(vma, &obj->vma_list, vma_link)
 			if (drm_mm_node_allocated(&vma->node)) {
 				ret = i915_vma_bind(vma, cache_level,
-						    vma->bound & GLOBAL_BIND);
+						    PIN_UPDATE);
 				if (ret)
 					return ret;
 			}
@@ -4187,10 +4186,8 @@ i915_gem_object_do_pin(struct drm_i915_gem_object *obj,
 						 flags);
 		if (IS_ERR(vma))
 			return PTR_ERR(vma);
-	}
-
-	if (flags & PIN_GLOBAL && !(vma->bound & GLOBAL_BIND)) {
-		ret = i915_vma_bind(vma, obj->cache_level, GLOBAL_BIND);
+	} else {
+		ret = i915_vma_bind(vma, obj->cache_level, flags);
 		if (ret)
 			return ret;
 	}
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 7f69aa820458..cfdc8c6073aa 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -400,10 +400,9 @@ i915_gem_execbuffer_relocate_entry(struct drm_i915_gem_object *obj,
 	 * pipe_control writes because the gpu doesn't properly redirect them
 	 * through the ppgtt for non_secure batchbuffers. */
 	if (unlikely(IS_GEN6(dev) &&
-	    reloc->write_domain == I915_GEM_DOMAIN_INSTRUCTION &&
-	    !(target_vma->bound & GLOBAL_BIND))) {
+	    reloc->write_domain == I915_GEM_DOMAIN_INSTRUCTION)) {
 		ret = i915_vma_bind(target_vma, target_i915_obj->cache_level,
-				    GLOBAL_BIND);
+				    PIN_GLOBAL);
 		if (WARN_ONCE(ret, "Unexpected failure to bind target VMA!"))
 			return ret;
 	}
@@ -585,7 +584,7 @@ i915_gem_execbuffer_reserve_vma(struct i915_vma *vma,
 	uint64_t flags;
 	int ret;
 
-	flags = 0;
+	flags = PIN_USER;
 	if (entry->flags & EXEC_OBJECT_NEEDS_GTT)
 		flags |= PIN_GLOBAL;
 
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 4e2caef83772..9e06180e206f 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -1748,15 +1748,7 @@ void i915_gem_restore_gtt_mappings(struct drm_device *dev)
 			continue;
 
 		i915_gem_clflush_object(obj, obj->pin_display);
-		/* The bind_vma code tries to be smart about tracking mappings.
-		 * Unfortunately above, we've just wiped out the mappings
-		 * without telling our object about it. So we need to fake it.
-		 *
-		 * Bind is not expected to fail since this is only called on
-		 * resume and assumption is all requirements exist already.
-		 */
-		vma->bound &= ~GLOBAL_BIND;
-		WARN_ON(i915_vma_bind(vma, obj->cache_level, GLOBAL_BIND));
+		WARN_ON(i915_vma_bind(vma, obj->cache_level, PIN_UPDATE));
 	}
 
 
@@ -1957,7 +1949,8 @@ static void i915_ggtt_bind_vma(struct i915_vma *vma,
 
 	BUG_ON(!i915_is_ggtt(vma->vm));
 	intel_gtt_insert_sg_entries(vma->ggtt_view.pages, entry, flags);
-	vma->bound = GLOBAL_BIND;
+
+	vma->bound |= GLOBAL_BIND;
 }
 
 static void i915_ggtt_clear_range(struct i915_address_space *vm,
@@ -1976,7 +1969,6 @@ static void i915_ggtt_unbind_vma(struct i915_vma *vma)
 	const unsigned int size = vma->obj->base.size >> PAGE_SHIFT;
 
 	BUG_ON(!i915_is_ggtt(vma->vm));
-	vma->bound = 0;
 	intel_gtt_clear_range(first, size);
 }
 
@@ -1997,35 +1989,19 @@ static void ggtt_bind_vma(struct i915_vma *vma,
 	if (i915_is_ggtt(vma->vm))
 		pages = vma->ggtt_view.pages;
 
-	/* If there is no aliasing PPGTT, or the caller needs a global mapping,
-	 * or we have a global mapping already but the cacheability flags have
-	 * changed, set the global PTEs.
-	 *
-	 * If there is an aliasing PPGTT it is anecdotally faster, so use that
-	 * instead if none of the above hold true.
-	 *
-	 * NB: A global mapping should only be needed for special regions like
-	 * "gtt mappable", SNB errata, or if specified via special execbuf
-	 * flags. At all other times, the GPU will use the aliasing PPGTT.
-	 */
 	if (!dev_priv->mm.aliasing_ppgtt || flags & GLOBAL_BIND) {
-		if (!(vma->bound & GLOBAL_BIND) ||
-		    (cache_level != obj->cache_level)) {
-			vma->vm->insert_entries(vma->vm, pages,
-						vma->node.start,
-						cache_level, pte_flags);
-			vma->bound |= GLOBAL_BIND;
-		}
+		vma->vm->insert_entries(vma->vm, pages,
+					vma->node.start,
+					cache_level, pte_flags);
+
+		vma->bound |= GLOBAL_BIND;
 	}
 
-	if (dev_priv->mm.aliasing_ppgtt &&
-	    (!(vma->bound & LOCAL_BIND) ||
-	     (cache_level != obj->cache_level))) {
+	if (dev_priv->mm.aliasing_ppgtt && flags & LOCAL_BIND) {
 		struct i915_hw_ppgtt *appgtt = dev_priv->mm.aliasing_ppgtt;
 		appgtt->base.insert_entries(&appgtt->base, pages,
 					    vma->node.start,
 					    cache_level, pte_flags);
-		vma->bound |= LOCAL_BIND;
 	}
 }
 
@@ -2040,16 +2016,14 @@ static void ggtt_unbind_vma(struct i915_vma *vma)
 				     vma->node.start,
 				     obj->base.size,
 				     true);
-		vma->bound &= ~GLOBAL_BIND;
 	}
 
-	if (vma->bound & LOCAL_BIND) {
+	if (dev_priv->mm.aliasing_ppgtt && vma->bound & LOCAL_BIND) {
 		struct i915_hw_ppgtt *appgtt = dev_priv->mm.aliasing_ppgtt;
 		appgtt->base.clear_range(&appgtt->base,
 					 vma->node.start,
 					 obj->base.size,
 					 true);
-		vma->bound &= ~LOCAL_BIND;
 	}
 }
 
@@ -2839,6 +2813,7 @@ i915_get_ggtt_vma_pages(struct i915_vma *vma)
 int i915_vma_bind(struct i915_vma *vma, enum i915_cache_level cache_level,
 		  u32 flags)
 {
+	u32 bind_flags = 0;
 	int ret;
 
 	if (vma->vm->allocate_va_range) {
@@ -2855,12 +2830,24 @@ int i915_vma_bind(struct i915_vma *vma, enum i915_cache_level cache_level,
 
 	if (i915_is_ggtt(vma->vm)) {
 		ret = i915_get_ggtt_vma_pages(vma);
-
 		if (ret)
-			return ret;
+			return 0;
 	}
 
-	vma->vm->bind_vma(vma, cache_level, flags);
+	if (flags & PIN_GLOBAL)
+		bind_flags |= GLOBAL_BIND;
+	if (flags & PIN_USER)
+		bind_flags |= LOCAL_BIND;
+
+	if (flags & PIN_UPDATE)
+		bind_flags |= vma->bound;
+	else
+		bind_flags &= ~vma->bound;
+
+	if (bind_flags)
+		vma->vm->bind_vma(vma, cache_level, bind_flags);
+
+	vma->bound |= bind_flags;
 
 	return 0;
 }
-- 
1.9.3



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