Commit-ID: 0318e5abe1c0933b8bf6763a1a0d3caec4f0826d Gitweb: http://git.kernel.org/tip/0318e5abe1c0933b8bf6763a1a0d3caec4f0826d Author: Kirill A. Shutemov <[email protected]> AuthorDate: Mon, 13 Mar 2017 17:33:06 +0300 Committer: Ingo Molnar <[email protected]> CommitDate: Tue, 14 Mar 2017 08:45:08 +0100
x86/mm/gup: Add 5-level paging support Extend get_user_pages_fast() to handle an additional page table level. Signed-off-by: Kirill A. Shutemov <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- arch/x86/mm/gup.c | 33 +++++++++++++++++++++++++++------ 1 file changed, 27 insertions(+), 6 deletions(-) diff --git a/arch/x86/mm/gup.c b/arch/x86/mm/gup.c index 1f3b6ef..456dfdf 100644 --- a/arch/x86/mm/gup.c +++ b/arch/x86/mm/gup.c @@ -76,9 +76,9 @@ static void undo_dev_pagemap(int *nr, int nr_start, struct page **pages) } /* - * 'pteval' can come from a pte, pmd or pud. We only check + * 'pteval' can come from a pte, pmd, pud or p4d. We only check * _PAGE_PRESENT, _PAGE_USER, and _PAGE_RW in here which are the - * same value on all 3 types. + * same value on all 4 types. */ static inline int pte_allows_gup(unsigned long pteval, int write) { @@ -295,13 +295,13 @@ static noinline int gup_huge_pud(pud_t pud, unsigned long addr, return 1; } -static int gup_pud_range(pgd_t pgd, unsigned long addr, unsigned long end, +static int gup_pud_range(p4d_t p4d, unsigned long addr, unsigned long end, int write, struct page **pages, int *nr) { unsigned long next; pud_t *pudp; - pudp = pud_offset(&pgd, addr); + pudp = pud_offset(&p4d, addr); do { pud_t pud = *pudp; @@ -320,6 +320,27 @@ static int gup_pud_range(pgd_t pgd, unsigned long addr, unsigned long end, return 1; } +static int gup_p4d_range(pgd_t pgd, unsigned long addr, unsigned long end, + int write, struct page **pages, int *nr) +{ + unsigned long next; + p4d_t *p4dp; + + p4dp = p4d_offset(&pgd, addr); + do { + p4d_t p4d = *p4dp; + + next = p4d_addr_end(addr, end); + if (p4d_none(p4d)) + return 0; + BUILD_BUG_ON(p4d_large(p4d)); + if (!gup_pud_range(p4d, addr, next, write, pages, nr)) + return 0; + } while (p4dp++, addr = next, addr != end); + + return 1; +} + /* * Like get_user_pages_fast() except its IRQ-safe in that it won't fall * back to the regular GUP. @@ -368,7 +389,7 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write, next = pgd_addr_end(addr, end); if (pgd_none(pgd)) break; - if (!gup_pud_range(pgd, addr, next, write, pages, &nr)) + if (!gup_p4d_range(pgd, addr, next, write, pages, &nr)) break; } while (pgdp++, addr = next, addr != end); local_irq_restore(flags); @@ -440,7 +461,7 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write, next = pgd_addr_end(addr, end); if (pgd_none(pgd)) goto slow; - if (!gup_pud_range(pgd, addr, next, write, pages, &nr)) + if (!gup_p4d_range(pgd, addr, next, write, pages, &nr)) goto slow; } while (pgdp++, addr = next, addr != end); local_irq_enable();
