From b3c3f5e69e25583703383d674e73d0ce26e731c3 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Tue, 12 Aug 2014 20:05:48 +0100 Subject: [PATCH] drm/i915: Do not access stolen memory directly by the CPU, even for error capture For stolen pages, since it is verboten to access them directly on many architectures, we have to read them through the GTT aperture. If they are not accessible through the aperture, then we have to abort. This was complicated by commit 8b6124a633d8095b0c8364f585edff9c59568a96 Author: Chris Wilson Date: Thu Jan 30 14:38:16 2014 +0000 drm/i915: Don't access snooped pages through the GTT (even for error capture) and the desire to use stolen memory for ringbuffers, contexts and batches in the future. Signed-off-by: Chris Wilson Reviewed-by: Mika Kuoppala Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_gpu_error.c | 50 ++++++++++++++++++++++------------- 1 file changed, 31 insertions(+), 19 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c index 35e70d5..6d280c07 100644 --- a/drivers/gpu/drm/i915/i915_gpu_error.c +++ b/drivers/gpu/drm/i915/i915_gpu_error.c @@ -561,10 +561,11 @@ static struct drm_i915_error_object * i915_error_object_create_sized(struct drm_i915_private *dev_priv, struct drm_i915_gem_object *src, struct i915_address_space *vm, - const int num_pages) + int num_pages) { struct drm_i915_error_object *dst; - int i; + bool use_ggtt; + int i = 0; u32 reloc_offset; if (src == NULL || src->pages == NULL) @@ -574,8 +575,32 @@ i915_error_object_create_sized(struct drm_i915_private *dev_priv, if (dst == NULL) return NULL; - reloc_offset = dst->gtt_offset = i915_gem_obj_offset(src, vm); - for (i = 0; i < num_pages; i++) { + dst->gtt_offset = i915_gem_obj_offset(src, vm); + + reloc_offset = dst->gtt_offset; + use_ggtt = (src->cache_level == I915_CACHE_NONE && + i915_is_ggtt(vm) && + src->has_global_gtt_mapping && + reloc_offset + num_pages * PAGE_SIZE <= dev_priv->gtt.mappable_end); + + /* Cannot access stolen address directly, try to use the aperture */ + if (src->stolen) { + use_ggtt = true; + + if (!src->has_global_gtt_mapping) + goto unwind; + + reloc_offset = i915_gem_obj_ggtt_offset(src); + if (reloc_offset + num_pages * PAGE_SIZE > dev_priv->gtt.mappable_end) + goto unwind; + } + + /* Cannot access snooped pages through the aperture */ + if (use_ggtt && src->cache_level != I915_CACHE_NONE && !HAS_LLC(dev_priv->dev)) + goto unwind; + + dst->page_count = num_pages; + while (num_pages--) { unsigned long flags; void *d; @@ -584,10 +609,7 @@ i915_error_object_create_sized(struct drm_i915_private *dev_priv, goto unwind; local_irq_save(flags); - if (src->cache_level == I915_CACHE_NONE && - reloc_offset < dev_priv->gtt.mappable_end && - src->has_global_gtt_mapping && - i915_is_ggtt(vm)) { + if (use_ggtt) { void __iomem *s; /* Simply ignore tiling or any overlapping fence. @@ -599,14 +621,6 @@ i915_error_object_create_sized(struct drm_i915_private *dev_priv, reloc_offset); memcpy_fromio(d, s, PAGE_SIZE); io_mapping_unmap_atomic(s); - } else if (src->stolen) { - unsigned long offset; - - offset = dev_priv->mm.stolen_base; - offset += src->stolen->start; - offset += i << PAGE_SHIFT; - - memcpy_fromio(d, (void __iomem *) offset, PAGE_SIZE); } else { struct page *page; void *s; @@ -623,11 +637,9 @@ i915_error_object_create_sized(struct drm_i915_private *dev_priv, } local_irq_restore(flags); - dst->pages[i] = d; - + dst->pages[i++] = d; reloc_offset += PAGE_SIZE; } - dst->page_count = num_pages; return dst; -- 2.7.4