From: Matthew Auld matthew.auld@intel.com
discrete cards optimise 64K GTT pages for local-memory, since everything should be allocated at 64K granularity. We say goodbye to sparse entries, and instead get a compact 256B page-table for 64K pages, which should be more cache friendly. 4K pages for local-memory are no longer supported by the HW.
Signed-off-by: Matthew Auld matthew.auld@intel.com Signed-off-by: Stuart Summers stuart.summers@intel.com Signed-off-by: Ramalingam C ramalingam.c@intel.com Cc: Joonas Lahtinen joonas.lahtinen@linux.intel.com Cc: Rodrigo Vivi rodrigo.vivi@intel.com --- .../gpu/drm/i915/gem/selftests/huge_pages.c | 60 ++++++++++ drivers/gpu/drm/i915/gt/gen8_ppgtt.c | 109 +++++++++++++++++- drivers/gpu/drm/i915/gt/intel_gtt.h | 3 + drivers/gpu/drm/i915/gt/intel_ppgtt.c | 1 + 4 files changed, 170 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c index 11f0aa65f8a3..ef3439b290ca 100644 --- a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c +++ b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c @@ -1483,6 +1483,65 @@ static int igt_ppgtt_sanity_check(void *arg) return err; }
+static int igt_ppgtt_compact(void *arg) +{ + struct drm_i915_private *i915 = arg; + struct drm_i915_gem_object *obj; + int err; + + /* + * Simple test to catch issues with compact 64K pages -- since the pt is + * compacted to 256B that gives us 32 entries per pt, however since the + * backing page for the pt is 4K, any extra entries we might incorrectly + * write out should be ignored by the HW. If ever hit such a case this + * test should catch it since some of our writes would land in scratch. + */ + + if (!HAS_64K_PAGES(i915)) { + pr_info("device lacks compact 64K page support, skipping\n"); + return 0; + } + + if (!HAS_LMEM(i915)) { + pr_info("device lacks LMEM support, skipping\n"); + return 0; + } + + /* We want the range to cover multiple page-table boundaries. */ + obj = i915_gem_object_create_lmem(i915, SZ_4M, 0); + if (IS_ERR(obj)) + return err; + + err = i915_gem_object_pin_pages_unlocked(obj); + if (err) + goto out_put; + + if (obj->mm.page_sizes.phys < I915_GTT_PAGE_SIZE_64K) { + pr_info("LMEM compact unable to allocate huge-page(s)\n"); + goto out_unpin; + } + + /* + * Disable 2M GTT pages by forcing the page-size to 64K for the GTT + * insertion. + */ + obj->mm.page_sizes.sg = I915_GTT_PAGE_SIZE_64K; + + err = igt_write_huge(i915, obj); + if (err) + pr_err("LMEM compact write-huge failed\n"); + +out_unpin: + i915_gem_object_unpin_pages(obj); +out_put: + i915_gem_object_put(obj); + + if (err == -ENOMEM) + err = 0; + + return err; +} + static int igt_tmpfs_fallback(void *arg) { struct drm_i915_private *i915 = arg; @@ -1740,6 +1799,7 @@ int i915_gem_huge_page_live_selftests(struct drm_i915_private *i915) SUBTEST(igt_tmpfs_fallback), SUBTEST(igt_ppgtt_smoke_huge), SUBTEST(igt_ppgtt_sanity_check), + SUBTEST(igt_ppgtt_compact), };
if (!HAS_PPGTT(i915)) { diff --git a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c index b012c50f7ce7..8d081497e87e 100644 --- a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c +++ b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c @@ -233,6 +233,8 @@ static u64 __gen8_ppgtt_clear(struct i915_address_space * const vm, start, end, lvl); } else { unsigned int count; + unsigned int pte = gen8_pd_index(start, 0); + unsigned int num_ptes; u64 *vaddr;
count = gen8_pt_count(start, end); @@ -242,10 +244,18 @@ static u64 __gen8_ppgtt_clear(struct i915_address_space * const vm, atomic_read(&pt->used)); GEM_BUG_ON(!count || count >= atomic_read(&pt->used));
+ num_ptes = count; + if (pt->is_compact) { + GEM_BUG_ON(num_ptes % 16); + GEM_BUG_ON(pte % 16); + num_ptes /= 16; + pte /= 16; + } + vaddr = px_vaddr(pt); - memset64(vaddr + gen8_pd_index(start, 0), + memset64(vaddr + pte, vm->scratch[0]->encode, - count); + num_ptes);
atomic_sub(count, &pt->used); start += count; @@ -453,6 +463,96 @@ gen8_ppgtt_insert_pte(struct i915_ppgtt *ppgtt, return idx; }
+static void +xehpsdv_ppgtt_insert_huge(struct i915_vma *vma, + struct sgt_dma *iter, + enum i915_cache_level cache_level, + u32 flags) +{ + const gen8_pte_t pte_encode = vma->vm->pte_encode(0, cache_level, flags); + unsigned int rem = sg_dma_len(iter->sg); + u64 start = vma->node.start; + + GEM_BUG_ON(!i915_vm_is_4lvl(vma->vm)); + + do { + struct i915_page_directory * const pdp = + gen8_pdp_for_page_address(vma->vm, start); + struct i915_page_directory * const pd = + i915_pd_entry(pdp, __gen8_pte_index(start, 2)); + struct i915_page_table *pt = + i915_pt_entry(pd, __gen8_pte_index(start, 1)); + gen8_pte_t encode = pte_encode; + unsigned int page_size; + gen8_pte_t *vaddr; + u16 index, max; + + max = I915_PDES; + + if (vma->page_sizes.sg & I915_GTT_PAGE_SIZE_2M && + IS_ALIGNED(iter->dma, I915_GTT_PAGE_SIZE_2M) && + rem >= I915_GTT_PAGE_SIZE_2M && + !__gen8_pte_index(start, 0)) { + index = __gen8_pte_index(start, 1); + encode |= GEN8_PDE_PS_2M; + page_size = I915_GTT_PAGE_SIZE_2M; + + vaddr = px_vaddr(pd); + } else { + if (encode & GEN12_PPGTT_PTE_LM) { + GEM_BUG_ON(!i915_gem_object_is_lmem(vma->obj)); + GEM_BUG_ON(__gen8_pte_index(start, 0) % 16); + GEM_BUG_ON(rem < I915_GTT_PAGE_SIZE_64K); + GEM_BUG_ON(!IS_ALIGNED(iter->dma, + I915_GTT_PAGE_SIZE_64K)); + + index = __gen8_pte_index(start, 0) / 16; + page_size = I915_GTT_PAGE_SIZE_64K; + + max /= 16; + + vaddr = px_vaddr(pd); + vaddr[__gen8_pte_index(start, 1)] |= GEN12_PDE_64K; + + pt->is_compact = true; + } else { + GEM_BUG_ON(i915_gem_object_is_lmem(vma->obj)); + GEM_BUG_ON(pt->is_compact); + index = __gen8_pte_index(start, 0); + page_size = I915_GTT_PAGE_SIZE; + } + + vaddr = px_vaddr(pt); + } + + do { + GEM_BUG_ON(rem < page_size); + vaddr[index++] = encode | iter->dma; + + start += page_size; + iter->dma += page_size; + rem -= page_size; + if (iter->dma >= iter->max) { + iter->sg = __sg_next(iter->sg); + if (!iter->sg) + break; + + rem = sg_dma_len(iter->sg); + if (!rem) + break; + + iter->dma = sg_dma_address(iter->sg); + iter->max = iter->dma + rem; + + if (unlikely(!IS_ALIGNED(iter->dma, page_size))) + break; + } + } while (rem >= page_size && index < max); + + vma->page_sizes.gtt |= page_size; + } while (iter->sg && sg_dma_len(iter->sg)); +} + static void gen8_ppgtt_insert_huge(struct i915_vma *vma, struct sgt_dma *iter, enum i915_cache_level cache_level, @@ -585,7 +685,10 @@ static void gen8_ppgtt_insert(struct i915_address_space *vm, struct sgt_dma iter = sgt_dma(vma);
if (vma->page_sizes.sg > I915_GTT_PAGE_SIZE) { - gen8_ppgtt_insert_huge(vma, &iter, cache_level, flags); + if (HAS_64K_PAGES(vm->i915)) + xehpsdv_ppgtt_insert_huge(vma, &iter, cache_level, flags); + else + gen8_ppgtt_insert_huge(vma, &iter, cache_level, flags); } else { u64 idx = vma->node.start >> GEN8_PTE_SHIFT;
diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.h b/drivers/gpu/drm/i915/gt/intel_gtt.h index b24a496c854e..ef6d5c70f4ff 100644 --- a/drivers/gpu/drm/i915/gt/intel_gtt.h +++ b/drivers/gpu/drm/i915/gt/intel_gtt.h @@ -91,6 +91,8 @@ typedef u64 gen8_pte_t;
#define GEN12_GGTT_PTE_LM BIT_ULL(1)
+#define GEN12_PDE_64K BIT(6) + /* * Cacheability Control is a 4-bit value. The low three bits are stored in bits * 3:1 of the PTE, while the fourth bit is stored in bit 11 of the PTE. @@ -159,6 +161,7 @@ struct i915_page_table { atomic_t used; struct i915_page_table *stash; }; + bool is_compact; };
struct i915_page_directory { diff --git a/drivers/gpu/drm/i915/gt/intel_ppgtt.c b/drivers/gpu/drm/i915/gt/intel_ppgtt.c index 083b3090c69c..f4cb6544cfac 100644 --- a/drivers/gpu/drm/i915/gt/intel_ppgtt.c +++ b/drivers/gpu/drm/i915/gt/intel_ppgtt.c @@ -26,6 +26,7 @@ struct i915_page_table *alloc_pt(struct i915_address_space *vm) return ERR_PTR(-ENOMEM); }
+ pt->is_compact = false; atomic_set(&pt->used, 0); return pt; }