[Intel-gfx] [PATCH v2 03/22] drm/i915: Micro-optimise gen8_ppgtt_insert_entries()
Chris Wilson
chris at chris-wilson.co.uk
Fri Feb 10 19:38:26 UTC 2017
Improve the sg iteration and in hte process eliminate a bug in
miscomputing the pml4 length as orig_nents<<PAGE_SHIFT is no longer the
full length of the sg table.
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
drivers/gpu/drm/i915/i915_gem_gtt.c | 157 +++++++++++++++++++-----------------
1 file changed, 82 insertions(+), 75 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index ca1f5fa6984f..fcb8d635aec0 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -751,9 +751,9 @@ static bool gen8_ppgtt_clear_pt(struct i915_address_space *vm,
unsigned int num_entries = gen8_pte_count(start, length);
unsigned int pte = gen8_pte_index(start);
unsigned int pte_end = pte + num_entries;
- gen8_pte_t *pt_vaddr;
- gen8_pte_t scratch_pte = gen8_pte_encode(vm->scratch_page.daddr,
- I915_CACHE_LLC);
+ gen8_pte_t scratch_pte =
+ gen8_pte_encode(vm->scratch_page.daddr, I915_CACHE_LLC);
+ gen8_pte_t *vaddr;
if (WARN_ON(!px_page(pt)))
return false;
@@ -766,12 +766,10 @@ static bool gen8_ppgtt_clear_pt(struct i915_address_space *vm,
return true;
}
- pt_vaddr = kmap_px(pt);
-
+ vaddr = kmap_px(pt);
while (pte < pte_end)
- pt_vaddr[pte++] = scratch_pte;
-
- kunmap_px(ppgtt, pt_vaddr);
+ vaddr[pte++] = scratch_pte;
+ kunmap_px(ppgtt, vaddr);
return false;
}
@@ -879,71 +877,93 @@ static void gen8_ppgtt_clear_range(struct i915_address_space *vm,
gen8_ppgtt_clear_pdp(vm, &ppgtt->pdp, start, length);
}
-static void
-gen8_ppgtt_insert_pte_entries(struct i915_address_space *vm,
+struct sgt_dma {
+ struct scatterlist *sg;
+ dma_addr_t dma, max;
+};
+
+static __always_inline bool
+gen8_ppgtt_insert_pte_entries(struct i915_hw_ppgtt *ppgtt,
struct i915_page_directory_pointer *pdp,
- struct sg_page_iter *sg_iter,
- uint64_t start,
+ struct sgt_dma *iter,
+ u64 start,
enum i915_cache_level cache_level)
{
- struct i915_hw_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
- gen8_pte_t *pt_vaddr;
- unsigned pdpe = gen8_pdpe_index(start);
- unsigned pde = gen8_pde_index(start);
- unsigned pte = gen8_pte_index(start);
+ unsigned int pdpe = gen8_pdpe_index(start);
+ unsigned int pde = gen8_pde_index(start);
+ unsigned int pte = gen8_pte_index(start);
+ struct i915_page_directory *pd;
+ const gen8_pte_t pte_encode = gen8_pte_encode(0, cache_level);
+ gen8_pte_t *vaddr;
+ bool ret = true;
- pt_vaddr = NULL;
+ pd = pdp->page_directory[pdpe];
+ vaddr = kmap_px(pd->page_table[pde]);
+ do {
+ vaddr[pte] = pte_encode | iter->dma;
+ iter->dma += PAGE_SIZE;
+ if (iter->dma >= iter->max) {
+ iter->sg = __sg_next(iter->sg);
+ if (!iter->sg) {
+ ret = false;
+ break;
+ }
- while (__sg_page_iter_next(sg_iter)) {
- if (pt_vaddr == NULL) {
- struct i915_page_directory *pd = pdp->page_directory[pdpe];
- struct i915_page_table *pt = pd->page_table[pde];
- pt_vaddr = kmap_px(pt);
+ iter->dma = sg_dma_address(iter->sg);
+ iter->max = iter->dma + iter->sg->length;
}
- pt_vaddr[pte] =
- gen8_pte_encode(sg_page_iter_dma_address(sg_iter),
- cache_level);
if (++pte == GEN8_PTES) {
- kunmap_px(ppgtt, pt_vaddr);
- pt_vaddr = NULL;
if (++pde == I915_PDES) {
- if (++pdpe == I915_PDPES_PER_PDP(vm->i915))
- break;
+ pd = pdp->page_directory[++pdpe];
pde = 0;
}
+
+ kunmap_px(ppgtt, vaddr);
+ vaddr = kmap_px(pd->page_table[pde]);
pte = 0;
}
- }
+ } while (1);
+ kunmap_px(ppgtt, vaddr);
- if (pt_vaddr)
- kunmap_px(ppgtt, pt_vaddr);
+ return ret;
}
-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)
+static void gen8_ppgtt_insert_3lvl(struct i915_address_space *vm,
+ struct sg_table *pages,
+ uint64_t start,
+ enum i915_cache_level cache_level,
+ u32 unused)
{
struct i915_hw_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
- struct sg_page_iter sg_iter;
+ struct sgt_dma iter = {
+ .sg = pages->sgl,
+ .dma = sg_dma_address(iter.sg),
+ .max = iter.dma + iter.sg->length,
+ };
- __sg_page_iter_start(&sg_iter, pages->sgl, sg_nents(pages->sgl), 0);
+ gen8_ppgtt_insert_pte_entries(ppgtt, &ppgtt->pdp, &iter,
+ start, cache_level);
+}
- if (!USES_FULL_48BIT_PPGTT(vm->i915)) {
- gen8_ppgtt_insert_pte_entries(vm, &ppgtt->pdp, &sg_iter, start,
- cache_level);
- } else {
- struct i915_page_directory_pointer *pdp;
- uint64_t pml4e;
- uint64_t length = (uint64_t)pages->orig_nents << PAGE_SHIFT;
+static void gen8_ppgtt_insert_4lvl(struct i915_address_space *vm,
+ struct sg_table *pages,
+ uint64_t start,
+ enum i915_cache_level cache_level,
+ u32 unused)
+{
+ struct i915_hw_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
+ struct sgt_dma iter = {
+ .sg = pages->sgl,
+ .dma = sg_dma_address(iter.sg),
+ .max = iter.dma + iter.sg->length,
+ };
+ struct i915_page_directory_pointer **pdps = ppgtt->pml4.pdps;
+ unsigned int pml4e = gen8_pml4e_index(start);
- gen8_for_each_pml4e(pdp, &ppgtt->pml4, start, length, pml4e) {
- gen8_ppgtt_insert_pte_entries(vm, pdp, &sg_iter,
- start, cache_level);
- }
- }
+ while (gen8_ppgtt_insert_pte_entries(ppgtt, pdps[pml4e++], &iter,
+ start, cache_level))
+ ;
}
static void gen8_free_page_tables(struct drm_i915_private *dev_priv,
@@ -1591,7 +1611,6 @@ static int gen8_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
ppgtt->base.start = 0;
ppgtt->base.cleanup = gen8_ppgtt_cleanup;
ppgtt->base.allocate_va_range = gen8_alloc_va_range;
- ppgtt->base.insert_entries = gen8_ppgtt_insert_entries;
ppgtt->base.clear_range = gen8_ppgtt_clear_range;
ppgtt->base.unbind_vma = ppgtt_unbind_vma;
ppgtt->base.bind_vma = ppgtt_bind_vma;
@@ -1606,6 +1625,8 @@ static int gen8_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
ppgtt->base.total = 1ULL << 48;
ppgtt->switch_mm = gen8_48b_mm_switch;
+
+ ppgtt->base.insert_entries = gen8_ppgtt_insert_4lvl;
} else {
ret = __pdp_init(dev_priv, &ppgtt->pdp);
if (ret)
@@ -1622,6 +1643,8 @@ static int gen8_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
if (ret)
goto free_scratch;
}
+
+ ppgtt->base.insert_entries = gen8_ppgtt_insert_3lvl;
}
if (intel_vgpu_active(dev_priv))
@@ -1888,11 +1911,6 @@ static void gen6_ppgtt_clear_range(struct i915_address_space *vm,
}
}
-struct sgt_dma {
- struct scatterlist *sg;
- dma_addr_t dma, max;
-};
-
static void gen6_ppgtt_insert_entries(struct i915_address_space *vm,
struct sg_table *pages,
uint64_t start,
@@ -2434,26 +2452,15 @@ static void gen8_ggtt_insert_entries(struct i915_address_space *vm,
struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
struct sgt_iter sgt_iter;
gen8_pte_t __iomem *gtt_entries;
- gen8_pte_t gtt_entry;
+ gen8_pte_t pte_encode = gen8_pte_encode(0, level);
dma_addr_t addr;
- int i = 0;
-
- gtt_entries = (gen8_pte_t __iomem *)ggtt->gsm + (start >> PAGE_SHIFT);
- for_each_sgt_dma(addr, sgt_iter, st) {
- gtt_entry = gen8_pte_encode(addr, level);
- gen8_set_pte(>t_entries[i++], gtt_entry);
- }
+ gtt_entries = (gen8_pte_t __iomem *)ggtt->gsm;
+ gtt_entries += start >> PAGE_SHIFT;
+ for_each_sgt_dma(addr, sgt_iter, st)
+ gen8_set_pte(gtt_entries++, pte_encode | addr);
- /*
- * XXX: This serves as a posting read to make sure that the PTE has
- * actually been updated. There is some concern that even though
- * registers and PTEs are within the same BAR that they are potentially
- * of NUMA access patterns. Therefore, even with the way we assume
- * hardware should work, we must keep this posting read for paranoia.
- */
- if (i != 0)
- WARN_ON(readq(>t_entries[i-1]) != gtt_entry);
+ wmb();
/* This next bit makes the above posting read even more important. We
* want to flush the TLBs only after we're certain all the PTE updates
--
2.11.0
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