Skip to content

Commit

Permalink
mm: remove CONFIG_ARCH_HAS_HUGEPD
Browse files Browse the repository at this point in the history 
powerpc was the only user of CONFIG_ARCH_HAS_HUGEPD and doesn't use it
anymore, so remove all related code.

Link: https://lkml.kernel.org/r/4b10c54c794780b955f3ad6c657d0199dd792146.1719928057.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <[email protected]>
Acked-by: Oscar Salvador <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Peter Xu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
  • Loading branch information
@chleroy @akpm00
chleroy authored and akpm00 committed Jul 12, 2024
1 parent 0c22e4b commit 8268614
Show file tree
Hide file tree
Showing 4 changed files with 9 additions and 258 deletions.
6 changes: 0 additions & 6 deletions include/linux/hugetlb.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -20,12 +20,6 @@ struct user_struct;
struct mmu_gather;
struct node;

#ifndef CONFIG_ARCH_HAS_HUGEPD
typedef struct { unsigned long pd; } hugepd_t;
#define is_hugepd(hugepd) (0)
#define __hugepd(x) ((hugepd_t) { (x) })
#endif

void free_huge_folio(struct folio *folio);

#ifdef CONFIG_HUGETLB_PAGE
Expand Down
10 changes: 0 additions & 10 deletions mm/Kconfig
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1126,16 +1126,6 @@ config DMAPOOL_TEST
config ARCH_HAS_PTE_SPECIAL
bool

#
# Some architectures require a special hugepage directory format that is
# required to support multiple hugepage sizes. For example a4fe3ce76
# "powerpc/mm: Allow more flexible layouts for hugepage pagetables"
# introduced it on powerpc. This allows for a more flexible hugepage
# pagetable layouts.
#
config ARCH_HAS_HUGEPD
bool

config MAPPING_DIRTY_HELPERS
bool

Expand Down
194 changes: 5 additions & 189 deletions mm/gup.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -462,7 +462,7 @@ static inline void mm_set_has_pinned_flag(unsigned long *mm_flags)

#ifdef CONFIG_MMU

#if defined(CONFIG_ARCH_HAS_HUGEPD) || defined(CONFIG_HAVE_GUP_FAST)
#ifdef CONFIG_HAVE_GUP_FAST
static int record_subpages(struct page *page, unsigned long sz,
unsigned long addr, unsigned long end,
struct page **pages)
Expand Down Expand Up @@ -572,154 +572,7 @@ static struct folio *try_grab_folio_fast(struct page *page, int refs,

return folio;
}
#endif /* CONFIG_ARCH_HAS_HUGEPD || CONFIG_HAVE_GUP_FAST */

#ifdef CONFIG_ARCH_HAS_HUGEPD
static unsigned long hugepte_addr_end(unsigned long addr, unsigned long end,
unsigned long sz)
{
unsigned long __boundary = (addr + sz) & ~(sz-1);
return (__boundary - 1 < end - 1) ? __boundary : end;
}

/*
* Returns 1 if succeeded, 0 if failed, -EMLINK if unshare needed.
*
* NOTE: for the same entry, gup-fast and gup-slow can return different
* results (0 v.s. -EMLINK) depending on whether vma is available. This is
* the expected behavior, where we simply want gup-fast to fallback to
* gup-slow to take the vma reference first.
*/
static int gup_hugepte(struct vm_area_struct *vma, pte_t *ptep, unsigned long sz,
unsigned long addr, unsigned long end, unsigned int flags,
struct page **pages, int *nr, bool fast)
{
unsigned long pte_end;
struct page *page;
struct folio *folio;
pte_t pte;
int refs;

pte_end = (addr + sz) & ~(sz-1);
if (pte_end < end)
end = pte_end;

pte = huge_ptep_get(vma->vm_mm, addr, ptep);

if (!pte_access_permitted(pte, flags & FOLL_WRITE))
return 0;

/* hugepages are never "special" */
VM_BUG_ON(!pfn_valid(pte_pfn(pte)));

page = pte_page(pte);
refs = record_subpages(page, sz, addr, end, pages + *nr);

if (fast) {
folio = try_grab_folio_fast(page, refs, flags);
if (!folio)
return 0;
} else {
folio = page_folio(page);
if (try_grab_folio(folio, refs, flags))
return 0;
}

if (unlikely(pte_val(pte) != pte_val(ptep_get(ptep)))) {
gup_put_folio(folio, refs, flags);
return 0;
}

if (!pte_write(pte) && gup_must_unshare(vma, flags, &folio->page)) {
gup_put_folio(folio, refs, flags);
return -EMLINK;
}

*nr += refs;
folio_set_referenced(folio);
return 1;
}

/*
* NOTE: currently GUP for a hugepd is only possible on hugetlbfs file
* systems on Power, which does not have issue with folio writeback against
* GUP updates. When hugepd will be extended to support non-hugetlbfs or
* even anonymous memory, we need to do extra check as what we do with most
* of the other folios. See writable_file_mapping_allowed() and
* gup_fast_folio_allowed() for more information.
*/
static int gup_hugepd(struct vm_area_struct *vma, hugepd_t hugepd,
unsigned long addr, unsigned int pdshift,
unsigned long end, unsigned int flags,
struct page **pages, int *nr, bool fast)
{
pte_t *ptep;
unsigned long sz = 1UL << hugepd_shift(hugepd);
unsigned long next;
int ret;

ptep = hugepte_offset(hugepd, addr, pdshift);
do {
next = hugepte_addr_end(addr, end, sz);
ret = gup_hugepte(vma, ptep, sz, addr, end, flags, pages, nr,
fast);
if (ret != 1)
return ret;
} while (ptep++, addr = next, addr != end);

return 1;
}

static struct page *follow_hugepd(struct vm_area_struct *vma, hugepd_t hugepd,
unsigned long addr, unsigned int pdshift,
unsigned int flags,
struct follow_page_context *ctx)
{
struct page *page;
struct hstate *h;
spinlock_t *ptl;
int nr = 0, ret;
pte_t *ptep;

/* Only hugetlb supports hugepd */
if (WARN_ON_ONCE(!is_vm_hugetlb_page(vma)))
return ERR_PTR(-EFAULT);

h = hstate_vma(vma);
ptep = hugepte_offset(hugepd, addr, pdshift);
ptl = huge_pte_lock(h, vma->vm_mm, ptep);
ret = gup_hugepd(vma, hugepd, addr, pdshift, addr + PAGE_SIZE,
flags, &page, &nr, false);
spin_unlock(ptl);

if (ret == 1) {
/* GUP succeeded */
WARN_ON_ONCE(nr != 1);
ctx->page_mask = (1U << huge_page_order(h)) - 1;
return page;
}

/* ret can be either 0 (translates to NULL) or negative */
return ERR_PTR(ret);
}
#else /* CONFIG_ARCH_HAS_HUGEPD */
static inline int gup_hugepd(struct vm_area_struct *vma, hugepd_t hugepd,
unsigned long addr, unsigned int pdshift,
unsigned long end, unsigned int flags,
struct page **pages, int *nr, bool fast)
{
return 0;
}

static struct page *follow_hugepd(struct vm_area_struct *vma, hugepd_t hugepd,
unsigned long addr, unsigned int pdshift,
unsigned int flags,
struct follow_page_context *ctx)
{
return NULL;
}
#endif /* CONFIG_ARCH_HAS_HUGEPD */

#endif /* CONFIG_HAVE_GUP_FAST */

static struct page *no_page_table(struct vm_area_struct *vma,
unsigned int flags, unsigned long address)
Expand Down Expand Up @@ -1089,9 +942,6 @@ static struct page *follow_pmd_mask(struct vm_area_struct *vma,
return no_page_table(vma, flags, address);
if (!pmd_present(pmdval))
return no_page_table(vma, flags, address);
if (unlikely(is_hugepd(__hugepd(pmd_val(pmdval)))))
return follow_hugepd(vma, __hugepd(pmd_val(pmdval)),
address, PMD_SHIFT, flags, ctx);
if (pmd_devmap(pmdval)) {
ptl = pmd_lock(mm, pmd);
page = follow_devmap_pmd(vma, address, pmd, flags, &ctx->pgmap);
Expand Down Expand Up @@ -1142,9 +992,6 @@ static struct page *follow_pud_mask(struct vm_area_struct *vma,
pud = READ_ONCE(*pudp);
if (!pud_present(pud))
return no_page_table(vma, flags, address);
if (unlikely(is_hugepd(__hugepd(pud_val(pud)))))
return follow_hugepd(vma, __hugepd(pud_val(pud)),
address, PUD_SHIFT, flags, ctx);
if (pud_leaf(pud)) {
ptl = pud_lock(mm, pudp);
page = follow_huge_pud(vma, address, pudp, flags, ctx);
Expand All @@ -1170,10 +1017,6 @@ static struct page *follow_p4d_mask(struct vm_area_struct *vma,
p4d = READ_ONCE(*p4dp);
BUILD_BUG_ON(p4d_leaf(p4d));

if (unlikely(is_hugepd(__hugepd(p4d_val(p4d)))))
return follow_hugepd(vma, __hugepd(p4d_val(p4d)),
address, P4D_SHIFT, flags, ctx);

if (!p4d_present(p4d) || p4d_bad(p4d))
return no_page_table(vma, flags, address);

Expand Down Expand Up @@ -1217,10 +1060,7 @@ static struct page *follow_page_mask(struct vm_area_struct *vma,
ctx->page_mask = 0;
pgd = pgd_offset(mm, address);

if (unlikely(is_hugepd(__hugepd(pgd_val(*pgd)))))
page = follow_hugepd(vma, __hugepd(pgd_val(*pgd)),
address, PGDIR_SHIFT, flags, ctx);
else if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
page = no_page_table(vma, flags, address);
else
page = follow_p4d_mask(vma, address, pgd, flags, ctx);
Expand Down Expand Up @@ -3362,15 +3202,6 @@ static int gup_fast_pmd_range(pud_t *pudp, pud_t pud, unsigned long addr,
pages, nr))
return 0;

} else if (unlikely(is_hugepd(__hugepd(pmd_val(pmd))))) {
/*
* architecture have different format for hugetlbfs
* pmd format and THP pmd format
*/
if (gup_hugepd(NULL, __hugepd(pmd_val(pmd)), addr,
PMD_SHIFT, next, flags, pages, nr,
true) != 1)
return 0;
} else if (!gup_fast_pte_range(pmd, pmdp, addr, next, flags,
pages, nr))
return 0;
Expand All @@ -3397,11 +3228,6 @@ static int gup_fast_pud_range(p4d_t *p4dp, p4d_t p4d, unsigned long addr,
if (!gup_fast_pud_leaf(pud, pudp, addr, next, flags,
pages, nr))
return 0;
} else if (unlikely(is_hugepd(__hugepd(pud_val(pud))))) {
if (gup_hugepd(NULL, __hugepd(pud_val(pud)), addr,
PUD_SHIFT, next, flags, pages, nr,
true) != 1)
return 0;
} else if (!gup_fast_pmd_range(pudp, pud, addr, next, flags,
pages, nr))
return 0;
Expand All @@ -3425,13 +3251,8 @@ static int gup_fast_p4d_range(pgd_t *pgdp, pgd_t pgd, unsigned long addr,
if (!p4d_present(p4d))
return 0;
BUILD_BUG_ON(p4d_leaf(p4d));
if (unlikely(is_hugepd(__hugepd(p4d_val(p4d))))) {
if (gup_hugepd(NULL, __hugepd(p4d_val(p4d)), addr,
P4D_SHIFT, next, flags, pages, nr,
true) != 1)
return 0;
} else if (!gup_fast_pud_range(p4dp, p4d, addr, next, flags,
pages, nr))
if (!gup_fast_pud_range(p4dp, p4d, addr, next, flags,
pages, nr))
return 0;
} while (p4dp++, addr = next, addr != end);

Expand All @@ -3455,11 +3276,6 @@ static void gup_fast_pgd_range(unsigned long addr, unsigned long end,
if (!gup_fast_pgd_leaf(pgd, pgdp, addr, next, flags,
pages, nr))
return;
} else if (unlikely(is_hugepd(__hugepd(pgd_val(pgd))))) {
if (gup_hugepd(NULL, __hugepd(pgd_val(pgd)), addr,
PGDIR_SHIFT, next, flags, pages, nr,
true) != 1)
return;
} else if (!gup_fast_p4d_range(pgdp, pgd, addr, next, flags,
pages, nr))
return;
Expand Down
57 changes: 4 additions & 53 deletions mm/pagewalk.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -73,45 +73,6 @@ static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
return err;
}

#ifdef CONFIG_ARCH_HAS_HUGEPD
static int walk_hugepd_range(hugepd_t *phpd, unsigned long addr,
unsigned long end, struct mm_walk *walk, int pdshift)
{
int err = 0;
const struct mm_walk_ops *ops = walk->ops;
int shift = hugepd_shift(*phpd);
int page_size = 1 << shift;

if (!ops->pte_entry)
return 0;

if (addr & (page_size - 1))
return 0;

for (;;) {
pte_t *pte;

spin_lock(&walk->mm->page_table_lock);
pte = hugepte_offset(*phpd, addr, pdshift);
err = ops->pte_entry(pte, addr, addr + page_size, walk);
spin_unlock(&walk->mm->page_table_lock);

if (err)
break;
if (addr >= end - page_size)
break;
addr += page_size;
}
return err;
}
#else
static int walk_hugepd_range(hugepd_t *phpd, unsigned long addr,
unsigned long end, struct mm_walk *walk, int pdshift)
{
return 0;
}
#endif

static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
struct mm_walk *walk)
{
Expand Down Expand Up @@ -159,10 +120,7 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
if (walk->vma)
split_huge_pmd(walk->vma, pmd, addr);

if (is_hugepd(__hugepd(pmd_val(*pmd))))
err = walk_hugepd_range((hugepd_t *)pmd, addr, next, walk, PMD_SHIFT);
else
err = walk_pte_range(pmd, addr, next, walk);
err = walk_pte_range(pmd, addr, next, walk);
if (err)
break;

Expand Down Expand Up @@ -215,10 +173,7 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
if (pud_none(*pud))
goto again;

if (is_hugepd(__hugepd(pud_val(*pud))))
err = walk_hugepd_range((hugepd_t *)pud, addr, next, walk, PUD_SHIFT);
else
err = walk_pmd_range(pud, addr, next, walk);
err = walk_pmd_range(pud, addr, next, walk);
if (err)
break;
} while (pud++, addr = next, addr != end);
Expand Down Expand Up @@ -250,9 +205,7 @@ static int walk_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end,
if (err)
break;
}
if (is_hugepd(__hugepd(p4d_val(*p4d))))
err = walk_hugepd_range((hugepd_t *)p4d, addr, next, walk, P4D_SHIFT);
else if (ops->pud_entry || ops->pmd_entry || ops->pte_entry)
if (ops->pud_entry || ops->pmd_entry || ops->pte_entry)
err = walk_pud_range(p4d, addr, next, walk);
if (err)
break;
Expand Down Expand Up @@ -287,9 +240,7 @@ static int walk_pgd_range(unsigned long addr, unsigned long end,
if (err)
break;
}
if (is_hugepd(__hugepd(pgd_val(*pgd))))
err = walk_hugepd_range((hugepd_t *)pgd, addr, next, walk, PGDIR_SHIFT);
else if (ops->p4d_entry || ops->pud_entry || ops->pmd_entry || ops->pte_entry)
if (ops->p4d_entry || ops->pud_entry || ops->pmd_entry || ops->pte_entry)
err = walk_p4d_range(pgd, addr, next, walk);
if (err)
break;
Expand Down

0 comments on commit 8268614

Please sign in to comment.