From: Jon Bloomfield Date: Mon, 6 Aug 2018 21:10:48 +0000 (-0700) Subject: drm/i915/gtt: Read-only pages for insert_entries on bdw+ X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=85e04705c9ea7a68ad0dd0c06abea6bd8fc2cc10;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git drm/i915/gtt: Read-only pages for insert_entries on bdw+ commit 250f8c8140ac0a5e5acb91891d6813f12778b224 upstream. Hook up the flags to allow read-only ppGTT mappings for gen8+ v2: Include a selftest to check that writes to a readonly PTE are dropped v3: Don't duplicate cpu_check() as we can just reuse it, and even worse don't wholesale copy the theory-of-operation comment from igt_ctx_exec without changing it to explain the intention behind the new test! v4: Joonas really likes magic mystery values Signed-off-by: Jon Bloomfield Cc: Joonas Lahtinen Cc: Matthew Auld Reviewed-by: Joonas Lahtinen Reviewed-by: Matthew Auld Link: https://patchwork.freedesktop.org/patch/msgid/20180712185315.3288-2-chris@chris-wilson.co.uk Signed-off-by: Jon Bloomfield Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index 088f9c03cbb4..acff88447bd6 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -177,7 +177,7 @@ static int ppgtt_bind_vma(struct i915_vma *vma, vma->pages = vma->obj->pages; - /* Currently applicable only to VLV */ + /* Applicable to VLV, and gen8+ */ if (vma->obj->gt_ro) pte_flags |= PTE_READ_ONLY; @@ -793,7 +793,8 @@ gen8_ppgtt_insert_pte_entries(struct i915_address_space *vm, struct i915_page_directory_pointer *pdp, struct sg_page_iter *sg_iter, uint64_t start, - enum i915_cache_level cache_level) + enum i915_cache_level cache_level, + u32 flags) { struct i915_hw_ppgtt *ppgtt = i915_vm_to_ppgtt(vm); gen8_pte_t *pt_vaddr; @@ -812,7 +813,7 @@ gen8_ppgtt_insert_pte_entries(struct i915_address_space *vm, pt_vaddr[pte] = gen8_pte_encode(sg_page_iter_dma_address(sg_iter), - cache_level, true, 0); + cache_level, true, flags); if (++pte == GEN8_PTES) { kunmap_px(ppgtt, pt_vaddr); pt_vaddr = NULL; @@ -833,7 +834,7 @@ static void gen8_ppgtt_insert_entries(struct i915_address_space *vm, struct sg_table *pages, uint64_t start, enum i915_cache_level cache_level, - u32 unused) + u32 flags) { struct i915_hw_ppgtt *ppgtt = i915_vm_to_ppgtt(vm); struct sg_page_iter sg_iter; @@ -842,7 +843,7 @@ static void gen8_ppgtt_insert_entries(struct i915_address_space *vm, if (!USES_FULL_48BIT_PPGTT(vm->dev)) { gen8_ppgtt_insert_pte_entries(vm, &ppgtt->pdp, &sg_iter, start, - cache_level); + cache_level, flags); } else { struct i915_page_directory_pointer *pdp; uint64_t pml4e; @@ -850,7 +851,7 @@ static void gen8_ppgtt_insert_entries(struct i915_address_space *vm, gen8_for_each_pml4e(pdp, &ppgtt->pml4, start, length, pml4e) { gen8_ppgtt_insert_pte_entries(vm, pdp, &sg_iter, - start, cache_level); + start, cache_level, flags); } } } @@ -1523,6 +1524,10 @@ static int gen8_ppgtt_init(struct i915_hw_ppgtt *ppgtt) ppgtt->base.clear_range = gen8_ppgtt_clear_range; ppgtt->base.unbind_vma = ppgtt_unbind_vma; ppgtt->base.bind_vma = ppgtt_bind_vma; + + /* From bdw, there is support for read-only pages in the PPGTT */ + ppgtt->base.has_read_only = true; + ppgtt->debug_dump = gen8_dump_ppgtt; if (USES_FULL_48BIT_PPGTT(ppgtt->base.dev)) { @@ -2335,7 +2340,7 @@ static void gen8_ggtt_insert_page(struct i915_address_space *vm, static void gen8_ggtt_insert_entries(struct i915_address_space *vm, struct sg_table *st, uint64_t start, - enum i915_cache_level level, u32 unused) + enum i915_cache_level level, u32 flags) { struct drm_i915_private *dev_priv = to_i915(vm->dev); struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm); @@ -2346,6 +2351,9 @@ static void gen8_ggtt_insert_entries(struct i915_address_space *vm, int rpm_atomic_seq; int i = 0; + /* The GTT does not support read-only mappings */ + GEM_BUG_ON(flags & PTE_READ_ONLY); + rpm_atomic_seq = assert_rpm_atomic_begin(dev_priv); gtt_entries = (gen8_pte_t __iomem *)ggtt->gsm + (start >> PAGE_SHIFT); @@ -2607,7 +2615,7 @@ static int ggtt_bind_vma(struct i915_vma *vma, if (ret) return ret; - /* Currently applicable only to VLV */ + /* Applicable to VLV (gen8+ do not support RO in the GGTT) */ if (obj->gt_ro) pte_flags |= PTE_READ_ONLY; @@ -3196,6 +3204,10 @@ int i915_ggtt_init_hw(struct drm_i915_private *dev_priv) ggtt->base.total -= PAGE_SIZE; i915_address_space_init(&ggtt->base, dev_priv); ggtt->base.total += PAGE_SIZE; + + /* Only VLV supports read-only GGTT mappings */ + ggtt->base.has_read_only = IS_VALLEYVIEW(dev_priv); + if (!HAS_LLC(dev_priv)) ggtt->base.mm.color_adjust = i915_gtt_color_adjust; diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h index ec78be2f8c77..43a0192242eb 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.h +++ b/drivers/gpu/drm/i915/i915_gem_gtt.h @@ -392,6 +392,9 @@ struct i915_address_space { */ struct list_head unbound_list; + /* Some systems support read-only mappings for GGTT and/or PPGTT */ + bool has_read_only:1; + /* FIXME: Need a more generic return type */ gen6_pte_t (*pte_encode)(dma_addr_t addr, enum i915_cache_level level, diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index 8babfe0ce4e3..418d1d142067 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -1951,6 +1951,7 @@ void intel_ring_unpin(struct intel_ring *ring) static struct i915_vma * intel_ring_create_vma(struct drm_i915_private *dev_priv, int size) { + struct i915_address_space *vm = &dev_priv->ggtt.base; struct drm_i915_gem_object *obj; struct i915_vma *vma; @@ -1960,10 +1961,14 @@ intel_ring_create_vma(struct drm_i915_private *dev_priv, int size) if (IS_ERR(obj)) return ERR_CAST(obj); - /* mark ring buffers as read-only from GPU side by default */ - obj->gt_ro = 1; + /* + * Mark ring buffers as read-only from GPU side (so no stray overwrites) + * if supported by the platform's GGTT. + */ + if (vm->has_read_only) + obj->gt_ro = 1; - vma = i915_vma_create(obj, &dev_priv->ggtt.base, NULL); + vma = i915_vma_create(obj, vm, NULL); if (IS_ERR(vma)) goto err;