[Intel-gfx] [PATCH v2 11/18] drm/i915/gen8: Add 4 level support in insert_entries and clear_range

[Michel Thierry]

When 48b is enabled, gen8_ppgtt_insert_entries needs to read the Page Map
Level 4 (PML4), before it selects which Page Directory Pointer (PDP)
it will write to.

Similarly, gen8_ppgtt_clear_range needs to get the correct PDP/PD range.

This patch was inspired by Ben's "Depend exclusively on map and
unmap_vma".

v2: Rebase after s/page_tables/page_table/.
v3: Remove unnecessary pdpe loop in gen8_ppgtt_clear_range_4lvl and use
clamp_pdp in gen8_ppgtt_insert_entries (Akash).
v4: Merge gen8_ppgtt_clear_range_4lvl into gen8_ppgtt_clear_range to
maintain symmetry with gen8_ppgtt_insert_entries (Akash).
v5: Do not mix pages and bytes in insert_entries (Akash).
v6: Prevent overflow in sg_nents << PAGE_SHIFT, when inserting 4GB at
once.
v7: Rebase after Mika's ppgtt cleanup / scratch merge patch series.
Use gen8_px_index functions, and remove unnecessary number of pages
parameter in insert_pte_entries.

Cc: Akash Goel <akash.goel at intel.com>
Signed-off-by: Michel Thierry <michel.thierry at intel.com>
---
 drivers/gpu/drm/i915/i915_gem_gtt.c | 51 ++++++++++++++++++++++++++++---------
 drivers/gpu/drm/i915/i915_gem_gtt.h | 11 ++++++++
 2 files changed, 50 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 1c9f662..9919c3b 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -817,9 +817,9 @@ static void gen8_ppgtt_clear_pte_range(struct i915_address_space *vm,
 	struct i915_hw_ppgtt *ppgtt =
 		container_of(vm, struct i915_hw_ppgtt, base);
 	gen8_pte_t *pt_vaddr;
-	unsigned pdpe = start >> GEN8_PDPE_SHIFT & GEN8_PDPE_MASK;
-	unsigned pde = start >> GEN8_PDE_SHIFT & GEN8_PDE_MASK;
-	unsigned pte = start >> GEN8_PTE_SHIFT & GEN8_PTE_MASK;
+	unsigned pdpe = gen8_pdpe_index(start);
+	unsigned pde = gen8_pde_index(start);
+	unsigned pte = gen8_pte_index(start);
 	unsigned num_entries = length >> PAGE_SHIFT;
 	unsigned last_pte, i;
 
@@ -869,12 +869,24 @@ static void gen8_ppgtt_clear_range(struct i915_address_space *vm,
 {
 	struct i915_hw_ppgtt *ppgtt =
 		container_of(vm, struct i915_hw_ppgtt, base);
-	struct i915_page_directory_pointer *pdp = &ppgtt->pdp; /* FIXME: 48b */
-
 	gen8_pte_t scratch_pte = gen8_pte_encode(px_dma(vm->scratch_page),
 						 I915_CACHE_LLC, use_scratch);
 
-	gen8_ppgtt_clear_pte_range(vm, pdp, start, length, scratch_pte);
+	if (!USES_FULL_48BIT_PPGTT(vm->dev)) {
+		gen8_ppgtt_clear_pte_range(vm, &ppgtt->pdp, start, length,
+					   scratch_pte);
+	} else {
+		uint64_t templ4, pml4e;
+		struct i915_page_directory_pointer *pdp;
+
+		gen8_for_each_pml4e(pdp, &ppgtt->pml4, start, length, templ4, pml4e) {
+			uint64_t pdp_len = gen8_clamp_pdp(start, length);
+			uint64_t pdp_start = start;
+
+			gen8_ppgtt_clear_pte_range(vm, pdp, pdp_start, pdp_len,
+						   scratch_pte);
+		}
+	}
 }
 
 static void
@@ -887,9 +899,9 @@ gen8_ppgtt_insert_pte_entries(struct i915_address_space *vm,
 	struct i915_hw_ppgtt *ppgtt =
 		container_of(vm, struct i915_hw_ppgtt, base);
 	gen8_pte_t *pt_vaddr;
-	unsigned pdpe = start >> GEN8_PDPE_SHIFT & GEN8_PDPE_MASK;
-	unsigned pde = start >> GEN8_PDE_SHIFT & GEN8_PDE_MASK;
-	unsigned pte = start >> GEN8_PTE_SHIFT & GEN8_PTE_MASK;
+	unsigned pdpe = gen8_pdpe_index(start);
+	unsigned pde = gen8_pde_index(start);
+	unsigned pte = gen8_pte_index(start);
 
 	pt_vaddr = NULL;
 
@@ -907,7 +919,8 @@ gen8_ppgtt_insert_pte_entries(struct i915_address_space *vm,
 			kunmap_px(ppgtt, pt_vaddr);
 			pt_vaddr = NULL;
 			if (++pde == I915_PDES) {
-				pdpe++;
+				if (++pdpe == I915_PDPES_PER_PDP(vm->dev))
+					break;
 				pde = 0;
 			}
 			pte = 0;
@@ -926,11 +939,25 @@ static void gen8_ppgtt_insert_entries(struct i915_address_space *vm,
 {
 	struct i915_hw_ppgtt *ppgtt =
 		container_of(vm, struct i915_hw_ppgtt, base);
-	struct i915_page_directory_pointer *pdp = &ppgtt->pdp; /* FIXME: 48b */
 	struct sg_page_iter sg_iter;
 
 	__sg_page_iter_start(&sg_iter, pages->sgl, sg_nents(pages->sgl), 0);
-	gen8_ppgtt_insert_pte_entries(vm, pdp, &sg_iter, start, cache_level);
+
+	if (!USES_FULL_48BIT_PPGTT(vm->dev)) {
+		gen8_ppgtt_insert_pte_entries(vm, &ppgtt->pdp, &sg_iter, start,
+					      cache_level);
+	} else {
+		struct i915_page_directory_pointer *pdp;
+		uint64_t templ4, pml4e;
+		uint64_t length = (uint64_t)sg_nents(pages->sgl) << PAGE_SHIFT;
+
+		gen8_for_each_pml4e(pdp, &ppgtt->pml4, start, length, templ4, pml4e) {
+			uint64_t pdp_start = start;
+
+			gen8_ppgtt_insert_pte_entries(vm, pdp, &sg_iter,
+						      pdp_start, cache_level);
+		}
+	}
 }
 
 static void gen8_free_page_tables(struct drm_device *dev,
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
index 5b04211..1803e91 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.h
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
@@ -472,6 +472,17 @@ static inline uint32_t gen6_pde_index(uint32_t addr)
 #define gen8_for_each_pdpe(pd, pdp, start, length, temp, iter)		\
 	gen8_for_each_pdpe_e(pd, pdp, start, length, temp, iter, I915_PDPES_PER_PDP(dev))
 
+/* Clamp length to the next page_directory pointer boundary */
+static inline uint64_t gen8_clamp_pdp(uint64_t start, uint64_t length)
+{
+	uint64_t next_pdp = ALIGN(start + 1, 1ULL << GEN8_PML4E_SHIFT);
+
+	if (next_pdp > (start + length))
+		return length;
+
+	return next_pdp - start;
+}
+
 static inline uint32_t gen8_pte_index(uint64_t address)
 {
 	return i915_pte_index(address, GEN8_PDE_SHIFT);
-- 
2.4.0