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Subject[PATCH 07/13] mm: remove the page_shift member from struct hmm_range
Date
All users pass PAGE_SIZE here, and if we wanted to support single
entries for huge pages we should really just add a HMM_FAULT_HUGEPAGE
flag instead that uses the huge page size instead of having the
caller calculate that size once, just for the hmm code to verify it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 1 -
drivers/gpu/drm/nouveau/nouveau_svm.c | 1 -
include/linux/hmm.h | 22 -------------
mm/hmm.c | 42 ++++++-------------------
4 files changed, 9 insertions(+), 57 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 71d6e7087b0b..8bf79288c4e2 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -818,7 +818,6 @@ int amdgpu_ttm_tt_get_user_pages(struct amdgpu_bo *bo, struct page **pages)
0 : range->flags[HMM_PFN_WRITE];
range->pfn_flags_mask = 0;
range->pfns = pfns;
- range->page_shift = PAGE_SHIFT;
range->start = start;
range->end = start + ttm->num_pages * PAGE_SIZE;

diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c
index 40e706234554..e7068ce46949 100644
--- a/drivers/gpu/drm/nouveau/nouveau_svm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_svm.c
@@ -680,7 +680,6 @@ nouveau_svm_fault(struct nvif_notify *notify)
args.i.p.addr + args.i.p.size, fn - fi);

/* Have HMM fault pages within the fault window to the GPU. */
- range.page_shift = PAGE_SHIFT;
range.start = args.i.p.addr;
range.end = args.i.p.addr + args.i.p.size;
range.pfns = args.phys;
diff --git a/include/linux/hmm.h b/include/linux/hmm.h
index c5b51376b453..51e18fbb8953 100644
--- a/include/linux/hmm.h
+++ b/include/linux/hmm.h
@@ -158,7 +158,6 @@ enum hmm_pfn_value_e {
* @values: pfn value for some special case (none, special, error, ...)
* @default_flags: default flags for the range (write, read, ... see hmm doc)
* @pfn_flags_mask: allows to mask pfn flags so that only default_flags matter
- * @page_shift: device virtual address shift value (should be >= PAGE_SHIFT)
* @pfn_shifts: pfn shift value (should be <= PAGE_SHIFT)
* @valid: pfns array did not change since it has been fill by an HMM function
*/
@@ -172,31 +171,10 @@ struct hmm_range {
const uint64_t *values;
uint64_t default_flags;
uint64_t pfn_flags_mask;
- uint8_t page_shift;
uint8_t pfn_shift;
bool valid;
};

-/*
- * hmm_range_page_shift() - return the page shift for the range
- * @range: range being queried
- * Return: page shift (page size = 1 << page shift) for the range
- */
-static inline unsigned hmm_range_page_shift(const struct hmm_range *range)
-{
- return range->page_shift;
-}
-
-/*
- * hmm_range_page_size() - return the page size for the range
- * @range: range being queried
- * Return: page size for the range in bytes
- */
-static inline unsigned long hmm_range_page_size(const struct hmm_range *range)
-{
- return 1UL << hmm_range_page_shift(range);
-}
-
/*
* hmm_range_wait_until_valid() - wait for range to be valid
* @range: range affected by invalidation to wait on
diff --git a/mm/hmm.c b/mm/hmm.c
index 926735a3aef9..f26d6abc4ed2 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -344,13 +344,12 @@ static int hmm_vma_walk_hole_(unsigned long addr, unsigned long end,
struct hmm_vma_walk *hmm_vma_walk = walk->private;
struct hmm_range *range = hmm_vma_walk->range;
uint64_t *pfns = range->pfns;
- unsigned long i, page_size;
+ unsigned long i;

hmm_vma_walk->last = addr;
- page_size = hmm_range_page_size(range);
- i = (addr - range->start) >> range->page_shift;
+ i = (addr - range->start) >> PAGE_SHIFT;

- for (; addr < end; addr += page_size, i++) {
+ for (; addr < end; addr += PAGE_SIZE, i++) {
pfns[i] = range->values[HMM_PFN_NONE];
if (fault || write_fault) {
int ret;
@@ -772,7 +771,7 @@ static int hmm_vma_walk_hugetlb_entry(pte_t *pte, unsigned long hmask,
struct mm_walk *walk)
{
#ifdef CONFIG_HUGETLB_PAGE
- unsigned long addr = start, i, pfn, mask, size, pfn_inc;
+ unsigned long addr = start, i, pfn, mask;
struct hmm_vma_walk *hmm_vma_walk = walk->private;
struct hmm_range *range = hmm_vma_walk->range;
struct vm_area_struct *vma = walk->vma;
@@ -783,24 +782,12 @@ static int hmm_vma_walk_hugetlb_entry(pte_t *pte, unsigned long hmask,
pte_t entry;
int ret = 0;

- size = huge_page_size(h);
- mask = size - 1;
- if (range->page_shift != PAGE_SHIFT) {
- /* Make sure we are looking at a full page. */
- if (start & mask)
- return -EINVAL;
- if (end < (start + size))
- return -EINVAL;
- pfn_inc = size >> PAGE_SHIFT;
- } else {
- pfn_inc = 1;
- size = PAGE_SIZE;
- }
+ mask = huge_page_size(h) - 1;

ptl = huge_pte_lock(hstate_vma(vma), walk->mm, pte);
entry = huge_ptep_get(pte);

- i = (start - range->start) >> range->page_shift;
+ i = (start - range->start) >> PAGE_SHIFT;
orig_pfn = range->pfns[i];
range->pfns[i] = range->values[HMM_PFN_NONE];
cpu_flags = pte_to_hmm_pfn_flags(range, entry);
@@ -812,8 +799,8 @@ static int hmm_vma_walk_hugetlb_entry(pte_t *pte, unsigned long hmask,
goto unlock;
}

- pfn = pte_pfn(entry) + ((start & mask) >> range->page_shift);
- for (; addr < end; addr += size, i++, pfn += pfn_inc)
+ pfn = pte_pfn(entry) + ((start & mask) >> PAGE_SHIFT);
+ for (; addr < end; addr += PAGE_SIZE, i++, pfn++)
range->pfns[i] = hmm_device_entry_from_pfn(range, pfn) |
cpu_flags;
hmm_vma_walk->last = end;
@@ -850,14 +837,13 @@ static void hmm_pfns_clear(struct hmm_range *range,
*/
int hmm_range_register(struct hmm_range *range, struct hmm_mirror *mirror)
{
- unsigned long mask = ((1UL << range->page_shift) - 1UL);
struct hmm *hmm = mirror->hmm;
unsigned long flags;

range->valid = false;
range->hmm = NULL;

- if ((range->start & mask) || (range->end & mask))
+ if ((range->start & (PAGE_SIZE - 1)) || (range->end & (PAGE_SIZE - 1)))
return -EINVAL;
if (range->start >= range->end)
return -EINVAL;
@@ -964,16 +950,6 @@ long hmm_range_fault(struct hmm_range *range, unsigned int flags)
if (vma == NULL || (vma->vm_flags & device_vma))
return -EFAULT;

- if (is_vm_hugetlb_page(vma)) {
- if (huge_page_shift(hstate_vma(vma)) !=
- range->page_shift &&
- range->page_shift != PAGE_SHIFT)
- return -EINVAL;
- } else {
- if (range->page_shift != PAGE_SHIFT)
- return -EINVAL;
- }
-
if (!(vma->vm_flags & VM_READ)) {
/*
* If vma do not allow read access, then assume that it
--
2.20.1
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