提交 092b50ba 编写于 作者: N Naoya Horiguchi 提交者: Linus Torvalds

pagemap: introduce data structure for pagemap entry

Currently a local variable of pagemap entry in pagemap_pte_range() is
named pfn and typed with u64, but it's not correct (pfn should be unsigned
long.)

This patch introduces special type for pagemap entries and replaces code
with it.
Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
上级 807f0ccf
...@@ -594,9 +594,13 @@ const struct file_operations proc_clear_refs_operations = { ...@@ -594,9 +594,13 @@ const struct file_operations proc_clear_refs_operations = {
.llseek = noop_llseek, .llseek = noop_llseek,
}; };
typedef struct {
u64 pme;
} pagemap_entry_t;
struct pagemapread { struct pagemapread {
int pos, len; int pos, len;
u64 *buffer; pagemap_entry_t *buffer;
}; };
#define PAGEMAP_WALK_SIZE (PMD_SIZE) #define PAGEMAP_WALK_SIZE (PMD_SIZE)
...@@ -619,10 +623,15 @@ struct pagemapread { ...@@ -619,10 +623,15 @@ struct pagemapread {
#define PM_NOT_PRESENT PM_PSHIFT(PAGE_SHIFT) #define PM_NOT_PRESENT PM_PSHIFT(PAGE_SHIFT)
#define PM_END_OF_BUFFER 1 #define PM_END_OF_BUFFER 1
static int add_to_pagemap(unsigned long addr, u64 pfn, static inline pagemap_entry_t make_pme(u64 val)
{
return (pagemap_entry_t) { .pme = val };
}
static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
struct pagemapread *pm) struct pagemapread *pm)
{ {
pm->buffer[pm->pos++] = pfn; pm->buffer[pm->pos++] = *pme;
if (pm->pos >= pm->len) if (pm->pos >= pm->len)
return PM_END_OF_BUFFER; return PM_END_OF_BUFFER;
return 0; return 0;
...@@ -634,8 +643,10 @@ static int pagemap_pte_hole(unsigned long start, unsigned long end, ...@@ -634,8 +643,10 @@ static int pagemap_pte_hole(unsigned long start, unsigned long end,
struct pagemapread *pm = walk->private; struct pagemapread *pm = walk->private;
unsigned long addr; unsigned long addr;
int err = 0; int err = 0;
pagemap_entry_t pme = make_pme(PM_NOT_PRESENT);
for (addr = start; addr < end; addr += PAGE_SIZE) { for (addr = start; addr < end; addr += PAGE_SIZE) {
err = add_to_pagemap(addr, PM_NOT_PRESENT, pm); err = add_to_pagemap(addr, &pme, pm);
if (err) if (err)
break; break;
} }
...@@ -648,36 +659,33 @@ static u64 swap_pte_to_pagemap_entry(pte_t pte) ...@@ -648,36 +659,33 @@ static u64 swap_pte_to_pagemap_entry(pte_t pte)
return swp_type(e) | (swp_offset(e) << MAX_SWAPFILES_SHIFT); return swp_type(e) | (swp_offset(e) << MAX_SWAPFILES_SHIFT);
} }
static u64 pte_to_pagemap_entry(pte_t pte) static void pte_to_pagemap_entry(pagemap_entry_t *pme, pte_t pte)
{ {
u64 pme = 0;
if (is_swap_pte(pte)) if (is_swap_pte(pte))
pme = PM_PFRAME(swap_pte_to_pagemap_entry(pte)) *pme = make_pme(PM_PFRAME(swap_pte_to_pagemap_entry(pte))
| PM_PSHIFT(PAGE_SHIFT) | PM_SWAP; | PM_PSHIFT(PAGE_SHIFT) | PM_SWAP);
else if (pte_present(pte)) else if (pte_present(pte))
pme = PM_PFRAME(pte_pfn(pte)) *pme = make_pme(PM_PFRAME(pte_pfn(pte))
| PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT; | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT);
return pme;
} }
#ifdef CONFIG_TRANSPARENT_HUGEPAGE #ifdef CONFIG_TRANSPARENT_HUGEPAGE
static u64 thp_pmd_to_pagemap_entry(pmd_t pmd, int offset) static void thp_pmd_to_pagemap_entry(pagemap_entry_t *pme,
pmd_t pmd, int offset)
{ {
u64 pme = 0;
/* /*
* Currently pmd for thp is always present because thp can not be * Currently pmd for thp is always present because thp can not be
* swapped-out, migrated, or HWPOISONed (split in such cases instead.) * swapped-out, migrated, or HWPOISONed (split in such cases instead.)
* This if-check is just to prepare for future implementation. * This if-check is just to prepare for future implementation.
*/ */
if (pmd_present(pmd)) if (pmd_present(pmd))
pme = PM_PFRAME(pmd_pfn(pmd) + offset) *pme = make_pme(PM_PFRAME(pmd_pfn(pmd) + offset)
| PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT; | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT);
return pme;
} }
#else #else
static inline u64 thp_pmd_to_pagemap_entry(pmd_t pmd, int offset) static inline void thp_pmd_to_pagemap_entry(pagemap_entry_t *pme,
pmd_t pmd, int offset)
{ {
return 0;
} }
#endif #endif
...@@ -688,7 +696,7 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, ...@@ -688,7 +696,7 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
struct pagemapread *pm = walk->private; struct pagemapread *pm = walk->private;
pte_t *pte; pte_t *pte;
int err = 0; int err = 0;
u64 pfn = PM_NOT_PRESENT; pagemap_entry_t pme = make_pme(PM_NOT_PRESENT);
if (pmd_trans_unstable(pmd)) if (pmd_trans_unstable(pmd))
return 0; return 0;
...@@ -702,8 +710,8 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, ...@@ -702,8 +710,8 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
offset = (addr & ~PAGEMAP_WALK_MASK) >> offset = (addr & ~PAGEMAP_WALK_MASK) >>
PAGE_SHIFT; PAGE_SHIFT;
pfn = thp_pmd_to_pagemap_entry(*pmd, offset); thp_pmd_to_pagemap_entry(&pme, *pmd, offset);
err = add_to_pagemap(addr, pfn, pm); err = add_to_pagemap(addr, &pme, pm);
if (err) if (err)
break; break;
} }
...@@ -723,11 +731,11 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, ...@@ -723,11 +731,11 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
if (vma && (vma->vm_start <= addr) && if (vma && (vma->vm_start <= addr) &&
!is_vm_hugetlb_page(vma)) { !is_vm_hugetlb_page(vma)) {
pte = pte_offset_map(pmd, addr); pte = pte_offset_map(pmd, addr);
pfn = pte_to_pagemap_entry(*pte); pte_to_pagemap_entry(&pme, *pte);
/* unmap before userspace copy */ /* unmap before userspace copy */
pte_unmap(pte); pte_unmap(pte);
} }
err = add_to_pagemap(addr, pfn, pm); err = add_to_pagemap(addr, &pme, pm);
if (err) if (err)
return err; return err;
} }
...@@ -738,13 +746,12 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, ...@@ -738,13 +746,12 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
} }
#ifdef CONFIG_HUGETLB_PAGE #ifdef CONFIG_HUGETLB_PAGE
static u64 huge_pte_to_pagemap_entry(pte_t pte, int offset) static void huge_pte_to_pagemap_entry(pagemap_entry_t *pme,
pte_t pte, int offset)
{ {
u64 pme = 0;
if (pte_present(pte)) if (pte_present(pte))
pme = PM_PFRAME(pte_pfn(pte) + offset) *pme = make_pme(PM_PFRAME(pte_pfn(pte) + offset)
| PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT; | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT);
return pme;
} }
/* This function walks within one hugetlb entry in the single call */ /* This function walks within one hugetlb entry in the single call */
...@@ -754,12 +761,12 @@ static int pagemap_hugetlb_range(pte_t *pte, unsigned long hmask, ...@@ -754,12 +761,12 @@ static int pagemap_hugetlb_range(pte_t *pte, unsigned long hmask,
{ {
struct pagemapread *pm = walk->private; struct pagemapread *pm = walk->private;
int err = 0; int err = 0;
u64 pfn; pagemap_entry_t pme = make_pme(PM_NOT_PRESENT);
for (; addr != end; addr += PAGE_SIZE) { for (; addr != end; addr += PAGE_SIZE) {
int offset = (addr & ~hmask) >> PAGE_SHIFT; int offset = (addr & ~hmask) >> PAGE_SHIFT;
pfn = huge_pte_to_pagemap_entry(*pte, offset); huge_pte_to_pagemap_entry(&pme, *pte, offset);
err = add_to_pagemap(addr, pfn, pm); err = add_to_pagemap(addr, &pme, pm);
if (err) if (err)
return err; return err;
} }
......
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