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author | Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> | 2014-11-05 16:27:40 (GMT) |
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committer | Michael Ellerman <mpe@ellerman.id.au> | 2014-11-14 06:24:21 (GMT) |
commit | f30c59e921f12b209852e1ddc197dc6a8fb0142b (patch) | |
tree | 392c066f3053fcf6f4683fbe6da3a0a06b091cc7 /mm/gup.c | |
parent | 06743521d0eae1263a09bccb1a92a9fbb94660b3 (diff) | |
download | linux-f30c59e921f12b209852e1ddc197dc6a8fb0142b.tar.xz |
mm: Update generic gup implementation to handle hugepage directory
Update generic gup implementation with powerpc specific details.
On powerpc at pmd level we can have hugepte, normal pmd pointer
or a pointer to the hugepage directory.
Tested-by: Steve Capper <steve.capper@linaro.org>
Acked-by: Steve Capper <steve.capper@linaro.org>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'mm/gup.c')
-rw-r--r-- | mm/gup.c | 81 |
1 files changed, 73 insertions, 8 deletions
@@ -3,7 +3,6 @@ #include <linux/err.h> #include <linux/spinlock.h> -#include <linux/hugetlb.h> #include <linux/mm.h> #include <linux/pagemap.h> #include <linux/rmap.h> @@ -12,6 +11,7 @@ #include <linux/sched.h> #include <linux/rwsem.h> +#include <linux/hugetlb.h> #include <asm/pgtable.h> #include "internal.h" @@ -875,6 +875,49 @@ static int gup_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr, return 1; } +static int gup_huge_pgd(pgd_t orig, pgd_t *pgdp, unsigned long addr, + unsigned long end, int write, + struct page **pages, int *nr) +{ + int refs; + struct page *head, *page, *tail; + + if (write && !pgd_write(orig)) + return 0; + + refs = 0; + head = pgd_page(orig); + page = head + ((addr & ~PGDIR_MASK) >> PAGE_SHIFT); + tail = page; + do { + VM_BUG_ON_PAGE(compound_head(page) != head, page); + pages[*nr] = page; + (*nr)++; + page++; + refs++; + } while (addr += PAGE_SIZE, addr != end); + + if (!page_cache_add_speculative(head, refs)) { + *nr -= refs; + return 0; + } + + if (unlikely(pgd_val(orig) != pgd_val(*pgdp))) { + *nr -= refs; + while (refs--) + put_page(head); + return 0; + } + + while (refs--) { + if (PageTail(tail)) + get_huge_page_tail(tail); + tail++; + } + + return 1; +} + static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end, int write, struct page **pages, int *nr) { @@ -902,6 +945,14 @@ static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end, 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_huge_pd(__hugepd(pmd_val(pmd)), addr, + PMD_SHIFT, next, write, pages, nr)) + return 0; } else if (!gup_pte_range(pmd, addr, next, write, pages, nr)) return 0; } while (pmdp++, addr = next, addr != end); @@ -909,22 +960,26 @@ static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end, return 1; } -static int gup_pud_range(pgd_t *pgdp, unsigned long addr, unsigned long end, - int write, struct page **pages, int *nr) +static int gup_pud_range(pgd_t pgd, unsigned long addr, unsigned long end, + int write, struct page **pages, int *nr) { unsigned long next; pud_t *pudp; - pudp = pud_offset(pgdp, addr); + pudp = pud_offset(&pgd, addr); do { pud_t pud = ACCESS_ONCE(*pudp); next = pud_addr_end(addr, end); if (pud_none(pud)) return 0; - if (pud_huge(pud)) { + if (unlikely(pud_huge(pud))) { if (!gup_huge_pud(pud, pudp, addr, next, write, - pages, nr)) + pages, nr)) + return 0; + } else if (unlikely(is_hugepd(__hugepd(pud_val(pud))))) { + if (!gup_huge_pd(__hugepd(pud_val(pud)), addr, + PUD_SHIFT, next, write, pages, nr)) return 0; } else if (!gup_pmd_range(pud, addr, next, write, pages, nr)) return 0; @@ -970,10 +1025,20 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write, local_irq_save(flags); pgdp = pgd_offset(mm, addr); do { + pgd_t pgd = ACCESS_ONCE(*pgdp); + next = pgd_addr_end(addr, end); - if (pgd_none(*pgdp)) + if (pgd_none(pgd)) break; - else if (!gup_pud_range(pgdp, addr, next, write, pages, &nr)) + if (unlikely(pgd_huge(pgd))) { + if (!gup_huge_pgd(pgd, pgdp, addr, next, write, + pages, &nr)) + break; + } else if (unlikely(is_hugepd(__hugepd(pgd_val(pgd))))) { + if (!gup_huge_pd(__hugepd(pgd_val(pgd)), addr, + PGDIR_SHIFT, next, write, pages, &nr)) + break; + } else if (!gup_pud_range(pgd, addr, next, write, pages, &nr)) break; } while (pgdp++, addr = next, addr != end); local_irq_restore(flags); |