From c5ad54cf7dd8922bd1cee2d5871aebf73dc9638e Mon Sep 17 00:00:00 2001 From: Joonas Lahtinen Date: Wed, 6 May 2015 14:36:09 +0300 Subject: [PATCH] drm/i915: Use partial view in mmap fault handler Use partial view for huge BOs (bigger than half the mappable aperture) in fault handler so that they can be accessed withough trying to make room for them by evicting other objects. v2: - Only use partial views in the case where early rejection was previously done. - Account variable type changes from previous reroll. v3: - Add a comment about overwriting existing page entries. (Tvrtko Ursulin) - Whitespace fixes. Cc: Chris Wilson Cc: Tvrtko Ursulin Signed-off-by: Joonas Lahtinen Reviewed-by: Tvrtko Ursulin Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_gem.c | 73 +++++++++++++++++++++++---------- 1 file changed, 51 insertions(+), 22 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 04d18bc7bf53..b45f93bb030e 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -1635,6 +1635,7 @@ int i915_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf) struct drm_i915_gem_object *obj = to_intel_bo(vma->vm_private_data); struct drm_device *dev = obj->base.dev; struct drm_i915_private *dev_priv = dev->dev_private; + struct i915_ggtt_view view = i915_ggtt_view_normal; pgoff_t page_offset; unsigned long pfn; int ret = 0; @@ -1667,8 +1668,21 @@ int i915_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf) goto unlock; } - /* Now bind it into the GTT if needed */ - ret = i915_gem_obj_ggtt_pin(obj, 0, PIN_MAPPABLE); + /* Use a partial view if the object is bigger than the aperture. */ + if (obj->base.size >= dev_priv->gtt.mappable_end) { + static const unsigned int chunk_size = 256; // 1 MiB + memset(&view, 0, sizeof(view)); + view.type = I915_GGTT_VIEW_PARTIAL; + view.params.partial.offset = rounddown(page_offset, chunk_size); + view.params.partial.size = + min_t(unsigned int, + chunk_size, + (vma->vm_end - vma->vm_start)/PAGE_SIZE - + view.params.partial.offset); + } + + /* Now pin it into the GTT if needed */ + ret = i915_gem_object_ggtt_pin(obj, &view, 0, PIN_MAPPABLE); if (ret) goto unlock; @@ -1681,30 +1695,50 @@ int i915_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf) goto unpin; /* Finally, remap it using the new GTT offset */ - pfn = dev_priv->gtt.mappable_base + i915_gem_obj_ggtt_offset(obj); + pfn = dev_priv->gtt.mappable_base + + i915_gem_obj_ggtt_offset_view(obj, &view); pfn >>= PAGE_SHIFT; - if (!obj->fault_mappable) { - unsigned long size = min_t(unsigned long, - vma->vm_end - vma->vm_start, - obj->base.size); - int i; + if (unlikely(view.type == I915_GGTT_VIEW_PARTIAL)) { + /* Overriding existing pages in partial view does not cause + * us any trouble as TLBs are still valid because the fault + * is due to userspace losing part of the mapping or never + * having accessed it before (at this partials' range). + */ + unsigned long base = vma->vm_start + + (view.params.partial.offset << PAGE_SHIFT); + unsigned int i; - for (i = 0; i < size >> PAGE_SHIFT; i++) { - ret = vm_insert_pfn(vma, - (unsigned long)vma->vm_start + i * PAGE_SIZE, - pfn + i); + for (i = 0; i < view.params.partial.size; i++) { + ret = vm_insert_pfn(vma, base + i * PAGE_SIZE, pfn + i); if (ret) break; } obj->fault_mappable = true; - } else - ret = vm_insert_pfn(vma, - (unsigned long)vmf->virtual_address, - pfn + page_offset); + } else { + if (!obj->fault_mappable) { + unsigned long size = min_t(unsigned long, + vma->vm_end - vma->vm_start, + obj->base.size); + int i; + + for (i = 0; i < size >> PAGE_SHIFT; i++) { + ret = vm_insert_pfn(vma, + (unsigned long)vma->vm_start + i * PAGE_SIZE, + pfn + i); + if (ret) + break; + } + + obj->fault_mappable = true; + } else + ret = vm_insert_pfn(vma, + (unsigned long)vmf->virtual_address, + pfn + page_offset); + } unpin: - i915_gem_object_ggtt_unpin(obj); + i915_gem_object_ggtt_unpin_view(obj, &view); unlock: mutex_unlock(&dev->struct_mutex); out: @@ -1897,11 +1931,6 @@ i915_gem_mmap_gtt(struct drm_file *file, goto unlock; } - if (obj->base.size > dev_priv->gtt.mappable_end) { - ret = -E2BIG; - goto out; - } - if (obj->madv != I915_MADV_WILLNEED) { DRM_DEBUG("Attempting to mmap a purgeable buffer\n"); ret = -EFAULT;