[PATCH 6/8] drm/amdgpu: meld together VM fragment and huge page handling
Christian König
ckoenig.leichtzumerken at gmail.com
Wed Sep 12 08:54:43 UTC 2018
This optimizes the generating of PTEs by walking the hierarchy only once
for a range and making changes as necessary.
It allows for both huge (2MB) as well giant (1GB) pages to be used on
Vega and Raven.
Signed-off-by: Christian König <christian.koenig at amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling at amd.com>
Acked-by: Junwei Zhang <Jerry.Zhang at amd.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 267 ++++++++++++++++++---------------
1 file changed, 147 insertions(+), 120 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 747b6ff6fea7..328325324a1d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -1488,46 +1488,76 @@ int amdgpu_vm_update_directories(struct amdgpu_device *adev,
}
/**
- * amdgpu_vm_handle_huge_pages - handle updating the PD with huge pages
+ * amdgpu_vm_update_huge - figure out parameters for PTE updates
*
- * @p: see amdgpu_pte_update_params definition
- * @entry: vm_pt entry to check
- * @parent: parent entry
- * @nptes: number of PTEs updated with this operation
- * @dst: destination address where the PTEs should point to
- * @flags: access flags fro the PTEs
- *
- * Check if we can update the PD with a huge page.
+ * Make sure to set the right flags for the PTEs at the desired level.
*/
-static void amdgpu_vm_handle_huge_pages(struct amdgpu_pte_update_params *p,
- struct amdgpu_vm_pt *entry,
- struct amdgpu_vm_pt *parent,
- unsigned nptes, uint64_t dst,
- uint64_t flags)
-{
- uint64_t pde;
+static void amdgpu_vm_update_huge(struct amdgpu_pte_update_params *params,
+ struct amdgpu_bo *bo, unsigned level,
+ uint64_t pe, uint64_t addr,
+ unsigned count, uint32_t incr,
+ uint64_t flags)
- /* In the case of a mixed PT the PDE must point to it*/
- if (p->adev->asic_type >= CHIP_VEGA10 && !p->src &&
- nptes == AMDGPU_VM_PTE_COUNT(p->adev)) {
- /* Set the huge page flag to stop scanning at this PDE */
+{
+ if (level != AMDGPU_VM_PTB) {
flags |= AMDGPU_PDE_PTE;
+ amdgpu_gmc_get_vm_pde(params->adev, level, &addr, &flags);
}
- if (!(flags & AMDGPU_PDE_PTE)) {
- if (entry->huge) {
- /* Add the entry to the relocated list to update it. */
- entry->huge = false;
- amdgpu_vm_bo_relocated(&entry->base);
- }
+ amdgpu_vm_update_func(params, bo, pe, addr, count, incr, flags);
+}
+
+/**
+ * amdgpu_vm_fragment - get fragment for PTEs
+ *
+ * @params: see amdgpu_pte_update_params definition
+ * @start: first PTE to handle
+ * @end: last PTE to handle
+ * @flags: hw mapping flags
+ * @frag: resulting fragment size
+ * @frag_end: end of this fragment
+ *
+ * Returns the first possible fragment for the start and end address.
+ */
+static void amdgpu_vm_fragment(struct amdgpu_pte_update_params *params,
+ uint64_t start, uint64_t end, uint64_t flags,
+ unsigned int *frag, uint64_t *frag_end)
+{
+ /**
+ * The MC L1 TLB supports variable sized pages, based on a fragment
+ * field in the PTE. When this field is set to a non-zero value, page
+ * granularity is increased from 4KB to (1 << (12 + frag)). The PTE
+ * flags are considered valid for all PTEs within the fragment range
+ * and corresponding mappings are assumed to be physically contiguous.
+ *
+ * The L1 TLB can store a single PTE for the whole fragment,
+ * significantly increasing the space available for translation
+ * caching. This leads to large improvements in throughput when the
+ * TLB is under pressure.
+ *
+ * The L2 TLB distributes small and large fragments into two
+ * asymmetric partitions. The large fragment cache is significantly
+ * larger. Thus, we try to use large fragments wherever possible.
+ * Userspace can support this by aligning virtual base address and
+ * allocation size to the fragment size.
+ */
+ unsigned max_frag = params->adev->vm_manager.fragment_size;
+
+ /* system pages are non continuously */
+ if (params->src || !(flags & AMDGPU_PTE_VALID)) {
+ *frag = 0;
+ *frag_end = end;
return;
}
- entry->huge = true;
- amdgpu_gmc_get_vm_pde(p->adev, AMDGPU_VM_PDB0, &dst, &flags);
-
- pde = (entry - parent->entries) * 8;
- amdgpu_vm_update_func(p, parent->base.bo, pde, dst, 1, 0, flags);
+ /* This intentionally wraps around if no bit is set */
+ *frag = min((unsigned)ffs(start) - 1, (unsigned)fls64(end - start) - 1);
+ if (*frag >= max_frag) {
+ *frag = max_frag;
+ *frag_end = end & ~((1ULL << max_frag) - 1);
+ } else {
+ *frag_end = start + (1 << *frag);
+ }
}
/**
@@ -1545,108 +1575,105 @@ static void amdgpu_vm_handle_huge_pages(struct amdgpu_pte_update_params *p,
* 0 for success, -EINVAL for failure.
*/
static int amdgpu_vm_update_ptes(struct amdgpu_pte_update_params *params,
- uint64_t start, uint64_t end,
- uint64_t dst, uint64_t flags)
+ uint64_t start, uint64_t end,
+ uint64_t dst, uint64_t flags)
{
struct amdgpu_device *adev = params->adev;
- const uint64_t mask = AMDGPU_VM_PTE_COUNT(adev) - 1;
struct amdgpu_vm_pt_cursor cursor;
+ uint64_t frag_start = start, frag_end;
+ unsigned int frag;
- /* walk over the address space and update the page tables */
- for_each_amdgpu_vm_pt_leaf(adev, params->vm, start, end - 1, cursor) {
+ /* figure out the initial fragment */
+ amdgpu_vm_fragment(params, frag_start, end, flags, &frag, &frag_end);
+
+ /* walk over the address space and update the PTs */
+ amdgpu_vm_pt_start(adev, params->vm, start, &cursor);
+ while (cursor.pfn < end) {
struct amdgpu_bo *pt = cursor.entry->base.bo;
- uint64_t pe_start;
- unsigned nptes;
+ unsigned shift, parent_shift, num_entries;
+ uint64_t incr, entry_end, pe_start;
- if (!pt || cursor.level != AMDGPU_VM_PTB)
+ if (!pt)
return -ENOENT;
- if ((cursor.pfn & ~mask) == (end & ~mask))
- nptes = end - cursor.pfn;
- else
- nptes = AMDGPU_VM_PTE_COUNT(adev) - (cursor.pfn & mask);
-
- amdgpu_vm_handle_huge_pages(params, cursor.entry, cursor.parent,
- nptes, dst, flags);
- /* We don't need to update PTEs for huge pages */
- if (cursor.entry->huge) {
- dst += nptes * AMDGPU_GPU_PAGE_SIZE;
+ /* The root level can't be a huge page */
+ if (cursor.level == adev->vm_manager.root_level) {
+ if (!amdgpu_vm_pt_descendant(adev, &cursor))
+ return -ENOENT;
continue;
}
- pe_start = (cursor.pfn & mask) * 8;
- amdgpu_vm_update_func(params, pt, pe_start, dst, nptes,
- AMDGPU_GPU_PAGE_SIZE, flags);
- dst += nptes * AMDGPU_GPU_PAGE_SIZE;
- }
-
- return 0;
-}
+ /* First check if the entry is already handled */
+ if (cursor.pfn < frag_start) {
+ cursor.entry->huge = true;
+ amdgpu_vm_pt_next(adev, &cursor);
+ continue;
+ }
-/*
- * amdgpu_vm_frag_ptes - add fragment information to PTEs
- *
- * @params: see amdgpu_pte_update_params definition
- * @vm: requested vm
- * @start: first PTE to handle
- * @end: last PTE to handle
- * @dst: addr those PTEs should point to
- * @flags: hw mapping flags
- *
- * Returns:
- * 0 for success, -EINVAL for failure.
- */
-static int amdgpu_vm_frag_ptes(struct amdgpu_pte_update_params *params,
- uint64_t start, uint64_t end,
- uint64_t dst, uint64_t flags)
-{
- /**
- * The MC L1 TLB supports variable sized pages, based on a fragment
- * field in the PTE. When this field is set to a non-zero value, page
- * granularity is increased from 4KB to (1 << (12 + frag)). The PTE
- * flags are considered valid for all PTEs within the fragment range
- * and corresponding mappings are assumed to be physically contiguous.
- *
- * The L1 TLB can store a single PTE for the whole fragment,
- * significantly increasing the space available for translation
- * caching. This leads to large improvements in throughput when the
- * TLB is under pressure.
- *
- * The L2 TLB distributes small and large fragments into two
- * asymmetric partitions. The large fragment cache is significantly
- * larger. Thus, we try to use large fragments wherever possible.
- * Userspace can support this by aligning virtual base address and
- * allocation size to the fragment size.
- */
- unsigned max_frag = params->adev->vm_manager.fragment_size;
- int r;
+ /* If it isn't already handled it can't be a huge page */
+ if (cursor.entry->huge) {
+ /* Add the entry to the relocated list to update it. */
+ cursor.entry->huge = false;
+ amdgpu_vm_bo_relocated(&cursor.entry->base);
+ }
- /* system pages are non continuously */
- if (params->src || !(flags & AMDGPU_PTE_VALID))
- return amdgpu_vm_update_ptes(params, start, end, dst, flags);
-
- while (start != end) {
- uint64_t frag_flags, frag_end;
- unsigned frag;
-
- /* This intentionally wraps around if no bit is set */
- frag = min((unsigned)ffs(start) - 1,
- (unsigned)fls64(end - start) - 1);
- if (frag >= max_frag) {
- frag_flags = AMDGPU_PTE_FRAG(max_frag);
- frag_end = end & ~((1ULL << max_frag) - 1);
- } else {
- frag_flags = AMDGPU_PTE_FRAG(frag);
- frag_end = start + (1 << frag);
+ shift = amdgpu_vm_level_shift(adev, cursor.level);
+ parent_shift = amdgpu_vm_level_shift(adev, cursor.level - 1);
+ if (adev->asic_type < CHIP_VEGA10) {
+ /* No huge page support before GMC v9 */
+ if (cursor.level != AMDGPU_VM_PTB) {
+ if (!amdgpu_vm_pt_descendant(adev, &cursor))
+ return -ENOENT;
+ continue;
+ }
+ } else if (frag < shift) {
+ /* We can't use this level when the fragment size is
+ * smaller than the address shift. Go to the next
+ * child entry and try again.
+ */
+ if (!amdgpu_vm_pt_descendant(adev, &cursor))
+ return -ENOENT;
+ continue;
+ } else if (frag >= parent_shift) {
+ /* If the fragment size is even larger than the parent
+ * shift we should go up one level and check it again.
+ */
+ if (!amdgpu_vm_pt_ancestor(&cursor))
+ return -ENOENT;
+ continue;
}
- r = amdgpu_vm_update_ptes(params, start, frag_end, dst,
- flags | frag_flags);
- if (r)
- return r;
+ /* Looks good so far, calculate parameters for the update */
+ incr = AMDGPU_GPU_PAGE_SIZE << shift;
+ num_entries = amdgpu_vm_num_entries(adev, cursor.level);
+ pe_start = ((cursor.pfn >> shift) & (num_entries - 1)) * 8;
+ entry_end = num_entries << shift;
+ entry_end += cursor.pfn & ~(entry_end - 1);
+ entry_end = min(entry_end, end);
+
+ do {
+ uint64_t upd_end = min(entry_end, frag_end);
+ unsigned nptes = (upd_end - frag_start) >> shift;
+
+ amdgpu_vm_update_huge(params, pt, cursor.level,
+ pe_start, dst, nptes, incr,
+ flags | AMDGPU_PTE_FRAG(frag));
+
+ pe_start += nptes * 8;
+ dst += nptes * AMDGPU_GPU_PAGE_SIZE << shift;
+
+ frag_start = upd_end;
+ if (frag_start >= frag_end) {
+ /* figure out the next fragment */
+ amdgpu_vm_fragment(params, frag_start, end,
+ flags, &frag, &frag_end);
+ if (frag < shift)
+ break;
+ }
+ } while (frag_start < entry_end);
- dst += (frag_end - start) * AMDGPU_GPU_PAGE_SIZE;
- start = frag_end;
+ if (frag >= shift)
+ amdgpu_vm_pt_next(adev, &cursor);
}
return 0;
@@ -1708,8 +1735,8 @@ static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev,
params.func = amdgpu_vm_cpu_set_ptes;
params.pages_addr = pages_addr;
- return amdgpu_vm_frag_ptes(¶ms, start, last + 1,
- addr, flags);
+ return amdgpu_vm_update_ptes(¶ms, start, last + 1,
+ addr, flags);
}
ring = container_of(vm->entity.rq->sched, struct amdgpu_ring, sched);
@@ -1788,7 +1815,7 @@ static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev,
if (r)
goto error_free;
- r = amdgpu_vm_frag_ptes(¶ms, start, last + 1, addr, flags);
+ r = amdgpu_vm_update_ptes(¶ms, start, last + 1, addr, flags);
if (r)
goto error_free;
--
2.14.1
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