forked from Minki/linux
c177c81e09
Currently hugepage migration is available for all archs which support pmd-level hugepage, but testing is done only for x86_64 and there're bugs for other archs. So to avoid breaking such archs, this patch limits the availability strictly to x86_64 until developers of other archs get interested in enabling this feature. Simply disabling hugepage migration on non-x86_64 archs is not enough to fix the reported problem where sys_move_pages() hits the BUG_ON() in follow_page(FOLL_GET), so let's fix this by checking if hugepage migration is supported in vma_migratable(). Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reported-by: Michael Ellerman <mpe@ellerman.id.au> Tested-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Hugh Dickins <hughd@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Miller <davem@davemloft.net> Cc: <stable@vger.kernel.org> [3.12+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
98 lines
2.0 KiB
C
98 lines
2.0 KiB
C
/*
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* MIPS Huge TLB Page Support for Kernel.
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 2002, Rohit Seth <rohit.seth@intel.com>
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* Copyright 2005, Embedded Alley Solutions, Inc.
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* Matt Porter <mporter@embeddedalley.com>
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* Copyright (C) 2008, 2009 Cavium Networks, Inc.
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*/
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/hugetlb.h>
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#include <linux/pagemap.h>
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#include <linux/err.h>
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#include <linux/sysctl.h>
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#include <asm/mman.h>
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#include <asm/tlb.h>
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#include <asm/tlbflush.h>
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pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr,
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unsigned long sz)
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{
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pgd_t *pgd;
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pud_t *pud;
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pte_t *pte = NULL;
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pgd = pgd_offset(mm, addr);
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pud = pud_alloc(mm, pgd, addr);
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if (pud)
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pte = (pte_t *)pmd_alloc(mm, pud, addr);
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return pte;
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}
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pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
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{
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pgd_t *pgd;
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pud_t *pud;
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pmd_t *pmd = NULL;
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pgd = pgd_offset(mm, addr);
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if (pgd_present(*pgd)) {
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pud = pud_offset(pgd, addr);
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if (pud_present(*pud))
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pmd = pmd_offset(pud, addr);
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}
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return (pte_t *) pmd;
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}
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int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
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{
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return 0;
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}
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/*
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* This function checks for proper alignment of input addr and len parameters.
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*/
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int is_aligned_hugepage_range(unsigned long addr, unsigned long len)
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{
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if (len & ~HPAGE_MASK)
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return -EINVAL;
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if (addr & ~HPAGE_MASK)
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return -EINVAL;
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return 0;
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}
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struct page *
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follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
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{
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return ERR_PTR(-EINVAL);
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}
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int pmd_huge(pmd_t pmd)
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{
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return (pmd_val(pmd) & _PAGE_HUGE) != 0;
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}
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int pud_huge(pud_t pud)
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{
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return (pud_val(pud) & _PAGE_HUGE) != 0;
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}
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struct page *
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follow_huge_pmd(struct mm_struct *mm, unsigned long address,
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pmd_t *pmd, int write)
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{
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struct page *page;
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page = pte_page(*(pte_t *)pmd);
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if (page)
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page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT);
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return page;
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}
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