From: Jérôme Glisse <jglisse@xxxxxxxxxx>
This patch modify the page table iterator to support empty range when
unmaping a range (ie when it is not trying to populate the range).
Signed-off-by: Jérôme Glisse <jglisse@xxxxxxxxxx>
Cc: Ben Skeggs <bskeggs@xxxxxxxxxx>
---
drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c | 75 ++++++++++++++++++---------
1 file changed, 51 insertions(+), 24 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c
index 93946dcee319..20d31526ba8f 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c
@@ -75,6 +75,7 @@ struct nvkm_vmm_iter {
struct nvkm_vmm *vmm;
u64 cnt;
u16 max, lvl;
+ u64 start, addr;
u32 pte[NVKM_VMM_LEVELS_MAX];
struct nvkm_vmm_pt *pt[NVKM_VMM_LEVELS_MAX];
int flush;
@@ -485,6 +486,23 @@ nvkm_vmm_ref_swpt(struct nvkm_vmm_iter *it, struct nvkm_vmm_pt *pgd, u32 pdei)
return true;
}
+static inline u64
+nvkm_vmm_iter_addr(const struct nvkm_vmm_iter *it,
+ const struct nvkm_vmm_desc *desc)
+{
+ int max = it->max;
+ u64 addr;
+
+ /* Reconstruct address */
+ addr = it->pte[max--];
+ do {
+ addr = addr << desc[max].bits;
+ addr |= it->pte[max];
+ } while (max--);
+
+ return addr;
+}
+
static inline u64
nvkm_vmm_iter(struct nvkm_vmm *vmm, const struct nvkm_vmm_page *page,
u64 addr, u64 size, const char *name, bool ref,
@@ -494,21 +512,23 @@ nvkm_vmm_iter(struct nvkm_vmm *vmm, const struct nvkm_vmm_page *page,
{
const struct nvkm_vmm_desc *desc = page->desc;
struct nvkm_vmm_iter it;
- u64 bits = addr >> page->shift;
+ u64 addr_bits = addr >> page->shift;
it.page = page;
it.desc = desc;
it.vmm = vmm;
it.cnt = size >> page->shift;
it.flush = NVKM_VMM_LEVELS_MAX;
+ it.start = it.addr = addr;
/* Deconstruct address into PTE indices for each mapping level. */
for (it.lvl = 0; desc[it.lvl].bits; it.lvl++) {
- it.pte[it.lvl] = bits & ((1 << desc[it.lvl].bits) - 1);
- bits >>= desc[it.lvl].bits;
+ it.pte[it.lvl] = addr_bits & ((1 << desc[it.lvl].bits) - 1);
+ addr_bits >>= desc[it.lvl].bits;
}
it.max = --it.lvl;
it.pt[it.max] = vmm->pd;
+ addr_bits = addr >> page->shift;
it.lvl = 0;
TRA(&it, "%s: %016llx %016llx %d %lld PTEs", name,
@@ -521,7 +541,8 @@ nvkm_vmm_iter(struct nvkm_vmm *vmm, const struct nvkm_vmm_page *page,
const int type = desc->type == SPT;
const u32 pten = 1 << desc->bits;
const u32 ptei = it.pte[0];
- const u32 ptes = min_t(u64, it.cnt, pten - ptei);
+ u32 ptes = min_t(u64, it.cnt, pten - ptei);
+ u64 tmp;
/* Walk down the tree, finding page tables for each level. */
for (; it.lvl; it.lvl--) {
@@ -529,9 +550,14 @@ nvkm_vmm_iter(struct nvkm_vmm *vmm, const struct nvkm_vmm_page *page,
struct nvkm_vmm_pt *pgd = pgt;
/* Software PT. */
- if (ref && NVKM_VMM_PDE_INVALID(pgd->pde[pdei])) {
- if (!nvkm_vmm_ref_swpt(&it, pgd, pdei))
- goto fail;
+ if (NVKM_VMM_PDE_INVALID(pgd->pde[pdei])) {
+ if (ref) {
+ if (!nvkm_vmm_ref_swpt(&it, pgd, pdei))
+ goto fail;
+ } else {
+ it.pte[it.lvl] += 1;
+ goto next;
+ }
}
it.pt[it.lvl - 1] = pgt = pgd->pde[pdei];
@@ -545,9 +571,16 @@ nvkm_vmm_iter(struct nvkm_vmm *vmm, const struct nvkm_vmm_page *page,
if (!nvkm_vmm_ref_hwpt(&it, pgd, pdei))
goto fail;
}
+
+ /* With HMM we might walk down un-populated range */
+ if (!pgt) {
+ it.pte[it.lvl] += 1;
+ goto next;
+ }
}
/* Handle PTE updates. */
+ it.addr = nvkm_vmm_iter_addr(&it, desc) << PAGE_SHIFT;
if (!REF_PTES || REF_PTES(&it, ptei, ptes)) {
struct nvkm_mmu_pt *pt = pgt->pt[type];
if (MAP_PTES || CLR_PTES) {
@@ -558,32 +591,26 @@ nvkm_vmm_iter(struct nvkm_vmm *vmm, const struct nvkm_vmm_page *page,
nvkm_vmm_flush_mark(&it);
}
}
+ it.pte[it.lvl] += ptes;
+next:
/* Walk back up the tree to the next position. */
- it.pte[it.lvl] += ptes;
- it.cnt -= ptes;
- if (it.cnt) {
- while (it.pte[it.lvl] == (1 << desc[it.lvl].bits)) {
- it.pte[it.lvl++] = 0;
- it.pte[it.lvl]++;
- }
+ while (it.pte[it.lvl] == (1 << desc[it.lvl].bits)) {
+ it.pte[it.lvl++] = 0;
+ if (it.lvl == it.max)
+ break;
+ it.pte[it.lvl]++;
}
+ tmp = nvkm_vmm_iter_addr(&it, desc);
+ it.cnt -= min_t(u64, it.cnt, tmp - addr_bits);
+ addr_bits = tmp;
};
nvkm_vmm_flush(&it);
return ~0ULL;
fail:
- /* Reconstruct the failure address so the caller is able to
- * reverse any partially completed operations.
- */
- addr = it.pte[it.max--];
- do {
- addr = addr << desc[it.max].bits;
- addr |= it.pte[it.max];
- } while (it.max--);
-
- return addr << page->shift;
+ return addr_bits << page->shift;
}
static void
--
2.14.3
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