Enable hardware performance counter support for perf events. If
disabled, perf events will use software events only.
+config SYS_SUPPORTS_HUGETLBFS
+ def_bool y
+
+config ARCH_WANT_GENERAL_HUGETLB
+ def_bool y
+
+config ARCH_WANT_HUGE_PMD_SHARE
+ def_bool y if !ARM64_64K_PAGES
+
+config HAVE_ARCH_TRANSPARENT_HUGEPAGE
+ def_bool y
+
source "mm/Kconfig"
config XEN_DOM0
help
Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
+config FORCE_MAX_ZONEORDER
+ int
+ default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE)
+ default "11"
+
endmenu
menu "Boot options"
--- /dev/null
+/*
+ * arch/arm64/include/asm/hugetlb.h
+ *
+ * Copyright (C) 2013 Linaro Ltd.
+ *
+ * Based on arch/x86/include/asm/hugetlb.h
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef __ASM_HUGETLB_H
+#define __ASM_HUGETLB_H
+
+#include <asm-generic/hugetlb.h>
+#include <asm/page.h>
+
+static inline pte_t huge_ptep_get(pte_t *ptep)
+{
+ return *ptep;
+}
+
+static inline void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pte)
+{
+ set_pte_at(mm, addr, ptep, pte);
+}
+
+static inline void huge_ptep_clear_flush(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *ptep)
+{
+ ptep_clear_flush(vma, addr, ptep);
+}
+
+static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
+ unsigned long addr, pte_t *ptep)
+{
+ ptep_set_wrprotect(mm, addr, ptep);
+}
+
+static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
+ unsigned long addr, pte_t *ptep)
+{
+ return ptep_get_and_clear(mm, addr, ptep);
+}
+
+static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *ptep,
+ pte_t pte, int dirty)
+{
+ return ptep_set_access_flags(vma, addr, ptep, pte, dirty);
+}
+
+static inline void hugetlb_free_pgd_range(struct mmu_gather *tlb,
+ unsigned long addr, unsigned long end,
+ unsigned long floor,
+ unsigned long ceiling)
+{
+ free_pgd_range(tlb, addr, end, floor, ceiling);
+}
+
+static inline int is_hugepage_only_range(struct mm_struct *mm,
+ unsigned long addr, unsigned long len)
+{
+ return 0;
+}
+
+static inline int prepare_hugepage_range(struct file *file,
+ unsigned long addr, unsigned long len)
+{
+ struct hstate *h = hstate_file(file);
+ if (len & ~huge_page_mask(h))
+ return -EINVAL;
+ if (addr & ~huge_page_mask(h))
+ return -EINVAL;
+ return 0;
+}
+
+static inline void hugetlb_prefault_arch_hook(struct mm_struct *mm)
+{
+}
+
+static inline int huge_pte_none(pte_t pte)
+{
+ return pte_none(pte);
+}
+
+static inline pte_t huge_pte_wrprotect(pte_t pte)
+{
+ return pte_wrprotect(pte);
+}
+
+static inline int arch_prepare_hugepage(struct page *page)
+{
+ return 0;
+}
+
+static inline void arch_release_hugepage(struct page *page)
+{
+}
+
+static inline void arch_clear_hugepage_flags(struct page *page)
+{
+ clear_bit(PG_dcache_clean, &page->flags);
+}
+
+#endif /* __ASM_HUGETLB_H */
/*
* Hardware page table definitions.
*
+ * Level 1 descriptor (PUD).
+ */
+
+#define PUD_TABLE_BIT (_AT(pgdval_t, 1) << 1)
+
+/*
* Level 2 descriptor (PMD).
*/
#define PMD_TYPE_MASK (_AT(pmdval_t, 3) << 0)
#define PMD_TYPE_FAULT (_AT(pmdval_t, 0) << 0)
#define PMD_TYPE_TABLE (_AT(pmdval_t, 3) << 0)
#define PMD_TYPE_SECT (_AT(pmdval_t, 1) << 0)
+#define PMD_TABLE_BIT (_AT(pmdval_t, 1) << 1)
/*
* Section
*/
-#define PMD_SECT_USER (_AT(pteval_t, 1) << 6) /* AP[1] */
+#define PMD_SECT_VALID (_AT(pmdval_t, 1) << 0)
+#define PMD_SECT_PROT_NONE (_AT(pmdval_t, 1) << 2)
+#define PMD_SECT_USER (_AT(pmdval_t, 1) << 6) /* AP[1] */
+#define PMD_SECT_RDONLY (_AT(pmdval_t, 1) << 7) /* AP[2] */
#define PMD_SECT_S (_AT(pmdval_t, 3) << 8)
#define PMD_SECT_AF (_AT(pmdval_t, 1) << 10)
#define PMD_SECT_NG (_AT(pmdval_t, 1) << 11)
#define PTE_TYPE_MASK (_AT(pteval_t, 3) << 0)
#define PTE_TYPE_FAULT (_AT(pteval_t, 0) << 0)
#define PTE_TYPE_PAGE (_AT(pteval_t, 3) << 0)
+#define PTE_TABLE_BIT (_AT(pteval_t, 1) << 1)
#define PTE_USER (_AT(pteval_t, 1) << 6) /* AP[1] */
#define PTE_RDONLY (_AT(pteval_t, 1) << 7) /* AP[2] */
#define PTE_SHARED (_AT(pteval_t, 3) << 8) /* SH[1:0], inner shareable */
* Software defined PTE bits definition.
*/
#define PTE_VALID (_AT(pteval_t, 1) << 0)
-#define PTE_PROT_NONE (_AT(pteval_t, 1) << 1) /* only when !PTE_VALID */
-#define PTE_FILE (_AT(pteval_t, 1) << 2) /* only when !pte_present() */
+#define PTE_PROT_NONE (_AT(pteval_t, 1) << 2) /* only when !PTE_VALID */
+#define PTE_FILE (_AT(pteval_t, 1) << 3) /* only when !pte_present() */
#define PTE_DIRTY (_AT(pteval_t, 1) << 55)
#define PTE_SPECIAL (_AT(pteval_t, 1) << 56)
#define _MOD_PROT(p, b) __pgprot_modify(p, 0, b)
-#define PAGE_NONE __pgprot_modify(pgprot_default, PTE_TYPE_MASK, PTE_PROT_NONE)
+#define PAGE_NONE __pgprot_modify(pgprot_default, PTE_TYPE_MASK, PTE_PROT_NONE | PTE_RDONLY | PTE_PXN | PTE_UXN)
#define PAGE_SHARED _MOD_PROT(pgprot_default, PTE_USER | PTE_NG | PTE_PXN | PTE_UXN)
#define PAGE_SHARED_EXEC _MOD_PROT(pgprot_default, PTE_USER | PTE_NG | PTE_PXN)
#define PAGE_COPY _MOD_PROT(pgprot_default, PTE_USER | PTE_NG | PTE_PXN | PTE_UXN | PTE_RDONLY)
#define PAGE_S2 __pgprot_modify(pgprot_default, PTE_S2_MEMATTR_MASK, PTE_S2_MEMATTR(MT_S2_NORMAL) | PTE_S2_RDONLY)
#define PAGE_S2_DEVICE __pgprot(PROT_DEFAULT | PTE_S2_MEMATTR(MT_S2_DEVICE_nGnRE) | PTE_S2_RDWR | PTE_UXN)
-#define __PAGE_NONE __pgprot(((_PAGE_DEFAULT) & ~PTE_TYPE_MASK) | PTE_PROT_NONE)
+#define __PAGE_NONE __pgprot(((_PAGE_DEFAULT) & ~PTE_TYPE_MASK) | PTE_PROT_NONE | PTE_RDONLY | PTE_PXN | PTE_UXN)
#define __PAGE_SHARED __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN)
#define __PAGE_SHARED_EXEC __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN)
#define __PAGE_COPY __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN | PTE_RDONLY)
/*
* Huge pte definitions.
*/
-#define pte_huge(pte) ((pte_val(pte) & PTE_TYPE_MASK) == PTE_TYPE_HUGEPAGE)
-#define pte_mkhuge(pte) (__pte((pte_val(pte) & ~PTE_TYPE_MASK) | PTE_TYPE_HUGEPAGE))
+#define pte_huge(pte) (!(pte_val(pte) & PTE_TABLE_BIT))
+#define pte_mkhuge(pte) (__pte(pte_val(pte) & ~PTE_TABLE_BIT))
+
+/*
+ * Hugetlb definitions.
+ */
+#define HUGE_MAX_HSTATE 2
+#define HPAGE_SHIFT PMD_SHIFT
+#define HPAGE_SIZE (_AC(1, UL) << HPAGE_SHIFT)
+#define HPAGE_MASK (~(HPAGE_SIZE - 1))
+#define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT)
#define __HAVE_ARCH_PTE_SPECIAL
+/*
+ * Software PMD bits for THP
+ */
+
+#define PMD_SECT_DIRTY (_AT(pmdval_t, 1) << 55)
+#define PMD_SECT_SPLITTING (_AT(pmdval_t, 1) << 57)
+
+/*
+ * THP definitions.
+ */
+#define pmd_young(pmd) (pmd_val(pmd) & PMD_SECT_AF)
+
+#define __HAVE_ARCH_PMD_WRITE
+#define pmd_write(pmd) (!(pmd_val(pmd) & PMD_SECT_RDONLY))
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+#define pmd_trans_huge(pmd) (pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT))
+#define pmd_trans_splitting(pmd) (pmd_val(pmd) & PMD_SECT_SPLITTING)
+#endif
+
+#define PMD_BIT_FUNC(fn,op) \
+static inline pmd_t pmd_##fn(pmd_t pmd) { pmd_val(pmd) op; return pmd; }
+
+PMD_BIT_FUNC(wrprotect, |= PMD_SECT_RDONLY);
+PMD_BIT_FUNC(mkold, &= ~PMD_SECT_AF);
+PMD_BIT_FUNC(mksplitting, |= PMD_SECT_SPLITTING);
+PMD_BIT_FUNC(mkwrite, &= ~PMD_SECT_RDONLY);
+PMD_BIT_FUNC(mkdirty, |= PMD_SECT_DIRTY);
+PMD_BIT_FUNC(mkyoung, |= PMD_SECT_AF);
+PMD_BIT_FUNC(mknotpresent, &= ~PMD_TYPE_MASK);
+
+#define pmd_mkhuge(pmd) (__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT))
+
+#define pmd_pfn(pmd) (((pmd_val(pmd) & PMD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
+#define pfn_pmd(pfn,prot) (__pmd(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
+#define mk_pmd(page,prot) pfn_pmd(page_to_pfn(page),prot)
+
+#define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
+
+static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
+{
+ const pmdval_t mask = PMD_SECT_USER | PMD_SECT_PXN | PMD_SECT_UXN |
+ PMD_SECT_RDONLY | PMD_SECT_PROT_NONE |
+ PMD_SECT_VALID;
+ pmd_val(pmd) = (pmd_val(pmd) & ~mask) | (pgprot_val(newprot) & mask);
+ return pmd;
+}
+
+#define set_pmd_at(mm, addr, pmdp, pmd) set_pmd(pmdp, pmd)
+
+static inline int has_transparent_hugepage(void)
+{
+ return 1;
+}
+
/*
* Mark the prot value as uncacheable and unbufferable.
*/
/*
* Encode and decode a swap entry:
- * bits 0-1: present (must be zero)
- * bit 2: PTE_FILE
- * bits 3-8: swap type
+ * bits 0, 2: present (must both be zero)
+ * bit 3: PTE_FILE
+ * bits 4-8: swap type
* bits 9-63: swap offset
*/
-#define __SWP_TYPE_SHIFT 3
+#define __SWP_TYPE_SHIFT 4
#define __SWP_TYPE_BITS 6
#define __SWP_TYPE_MASK ((1 << __SWP_TYPE_BITS) - 1)
#define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
/*
* Encode and decode a file entry:
- * bits 0-1: present (must be zero)
- * bit 2: PTE_FILE
- * bits 3-63: file offset / PAGE_SIZE
+ * bits 0, 2: present (must both be zero)
+ * bit 3: PTE_FILE
+ * bits 4-63: file offset / PAGE_SIZE
*/
#define pte_file(pte) (pte_val(pte) & PTE_FILE)
-#define pte_to_pgoff(x) (pte_val(x) >> 3)
-#define pgoff_to_pte(x) __pte(((x) << 3) | PTE_FILE)
+#define pte_to_pgoff(x) (pte_val(x) >> 4)
+#define pgoff_to_pte(x) __pte(((x) << 4) | PTE_FILE)
-#define PTE_FILE_MAX_BITS 61
+#define PTE_FILE_MAX_BITS 60
extern int kern_addr_valid(unsigned long addr);
#define tlb_migrate_finish(mm) do { } while (0)
+static inline void
+tlb_remove_pmd_tlb_entry(struct mmu_gather *tlb, pmd_t *pmdp, unsigned long addr)
+{
+ tlb_add_flush(tlb, addr);
+}
+
#endif
dsb();
}
+#define update_mmu_cache_pmd(vma, address, pmd) do { } while (0)
+
#endif
#endif
cache.o copypage.o flush.o \
ioremap.o mmap.o pgd.o mmu.o \
context.o tlb.o proc.o
+obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
return 0;
}
-/*
- * Some section permission faults need to be handled gracefully. They can
- * happen due to a __{get,put}_user during an oops.
- */
-static int do_sect_fault(unsigned long addr, unsigned int esr,
- struct pt_regs *regs)
-{
- do_bad_area(addr, esr, regs);
- return 0;
-}
-
/*
* This abort handler always returns "fault".
*/
{ do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 2 translation fault" },
{ do_page_fault, SIGSEGV, SEGV_MAPERR, "level 3 translation fault" },
{ do_bad, SIGBUS, 0, "reserved access flag fault" },
- { do_bad, SIGSEGV, SEGV_ACCERR, "level 1 access flag fault" },
- { do_bad, SIGSEGV, SEGV_ACCERR, "level 2 access flag fault" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 access flag fault" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 access flag fault" },
{ do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 access flag fault" },
{ do_bad, SIGBUS, 0, "reserved permission fault" },
- { do_bad, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" },
- { do_sect_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" },
{ do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" },
{ do_bad, SIGBUS, 0, "synchronous external abort" },
{ do_bad, SIGBUS, 0, "asynchronous external abort" },
--- /dev/null
+/*
+ * arch/arm64/mm/hugetlbpage.c
+ *
+ * Copyright (C) 2013 Linaro Ltd.
+ *
+ * Based on arch/x86/mm/hugetlbpage.c.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+#include <linux/pagemap.h>
+#include <linux/err.h>
+#include <linux/sysctl.h>
+#include <asm/mman.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+#include <asm/pgalloc.h>
+
+#ifndef CONFIG_ARCH_WANT_HUGE_PMD_SHARE
+int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
+{
+ return 0;
+}
+#endif
+
+struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
+ int write)
+{
+ return ERR_PTR(-EINVAL);
+}
+
+int pmd_huge(pmd_t pmd)
+{
+ return !(pmd_val(pmd) & PMD_TABLE_BIT);
+}
+
+int pud_huge(pud_t pud)
+{
+ return !(pud_val(pud) & PUD_TABLE_BIT);
+}
+
+static __init int setup_hugepagesz(char *opt)
+{
+ unsigned long ps = memparse(opt, &opt);
+ if (ps == PMD_SIZE) {
+ hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
+ } else if (ps == PUD_SIZE) {
+ hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
+ } else {
+ pr_err("hugepagesz: Unsupported page size %lu M\n", ps >> 20);
+ return 0;
+ }
+ return 1;
+}
+__setup("hugepagesz=", setup_hugepagesz);
{
struct memblock_region *reg;
+ /*
+ * Temporarily limit the memblock range. We need to do this as
+ * create_mapping requires puds, pmds and ptes to be allocated from
+ * memory addressable from the initial direct kernel mapping.
+ *
+ * The initial direct kernel mapping, located at swapper_pg_dir,
+ * gives us PGDIR_SIZE memory starting from PHYS_OFFSET (aligned).
+ */
+ memblock_set_current_limit((PHYS_OFFSET & PGDIR_MASK) + PGDIR_SIZE);
+
/* map all the memory banks */
for_each_memblock(memory, reg) {
phys_addr_t start = reg->base;
create_mapping(start, __phys_to_virt(start), end - start);
}
+
+ /* Limit no longer required. */
+ memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE);
}
/*
{
void *zero_page;
- /*
- * Maximum PGDIR_SIZE addressable via the initial direct kernel
- * mapping in swapper_pg_dir.
- */
- memblock_set_current_limit((PHYS_OFFSET & PGDIR_MASK) + PGDIR_SIZE);
-
init_mem_pgprot();
map_mem();
config ARCH_SUSPEND_POSSIBLE
def_bool y
+config ARCH_WANT_HUGE_PMD_SHARE
+ def_bool y
+
+config ARCH_WANT_GENERAL_HUGETLB
+ def_bool y
+
config ZONE_DMA32
bool
default X86_64
#include <asm/tlbflush.h>
#include <asm/pgalloc.h>
-static unsigned long page_table_shareable(struct vm_area_struct *svma,
- struct vm_area_struct *vma,
- unsigned long addr, pgoff_t idx)
-{
- unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) +
- svma->vm_start;
- unsigned long sbase = saddr & PUD_MASK;
- unsigned long s_end = sbase + PUD_SIZE;
-
- /* Allow segments to share if only one is marked locked */
- unsigned long vm_flags = vma->vm_flags & ~VM_LOCKED;
- unsigned long svm_flags = svma->vm_flags & ~VM_LOCKED;
-
- /*
- * match the virtual addresses, permission and the alignment of the
- * page table page.
- */
- if (pmd_index(addr) != pmd_index(saddr) ||
- vm_flags != svm_flags ||
- sbase < svma->vm_start || svma->vm_end < s_end)
- return 0;
-
- return saddr;
-}
-
-static int vma_shareable(struct vm_area_struct *vma, unsigned long addr)
-{
- unsigned long base = addr & PUD_MASK;
- unsigned long end = base + PUD_SIZE;
-
- /*
- * check on proper vm_flags and page table alignment
- */
- if (vma->vm_flags & VM_MAYSHARE &&
- vma->vm_start <= base && end <= vma->vm_end)
- return 1;
- return 0;
-}
-
-/*
- * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc()
- * and returns the corresponding pte. While this is not necessary for the
- * !shared pmd case because we can allocate the pmd later as well, it makes the
- * code much cleaner. pmd allocation is essential for the shared case because
- * pud has to be populated inside the same i_mmap_mutex section - otherwise
- * racing tasks could either miss the sharing (see huge_pte_offset) or select a
- * bad pmd for sharing.
- */
-static pte_t *
-huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
-{
- struct vm_area_struct *vma = find_vma(mm, addr);
- struct address_space *mapping = vma->vm_file->f_mapping;
- pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) +
- vma->vm_pgoff;
- struct vm_area_struct *svma;
- unsigned long saddr;
- pte_t *spte = NULL;
- pte_t *pte;
-
- if (!vma_shareable(vma, addr))
- return (pte_t *)pmd_alloc(mm, pud, addr);
-
- mutex_lock(&mapping->i_mmap_mutex);
- vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) {
- if (svma == vma)
- continue;
-
- saddr = page_table_shareable(svma, vma, addr, idx);
- if (saddr) {
- spte = huge_pte_offset(svma->vm_mm, saddr);
- if (spte) {
- get_page(virt_to_page(spte));
- break;
- }
- }
- }
-
- if (!spte)
- goto out;
-
- spin_lock(&mm->page_table_lock);
- if (pud_none(*pud))
- pud_populate(mm, pud, (pmd_t *)((unsigned long)spte & PAGE_MASK));
- else
- put_page(virt_to_page(spte));
- spin_unlock(&mm->page_table_lock);
-out:
- pte = (pte_t *)pmd_alloc(mm, pud, addr);
- mutex_unlock(&mapping->i_mmap_mutex);
- return pte;
-}
-
-/*
- * unmap huge page backed by shared pte.
- *
- * Hugetlb pte page is ref counted at the time of mapping. If pte is shared
- * indicated by page_count > 1, unmap is achieved by clearing pud and
- * decrementing the ref count. If count == 1, the pte page is not shared.
- *
- * called with vma->vm_mm->page_table_lock held.
- *
- * returns: 1 successfully unmapped a shared pte page
- * 0 the underlying pte page is not shared, or it is the last user
- */
-int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
-{
- pgd_t *pgd = pgd_offset(mm, *addr);
- pud_t *pud = pud_offset(pgd, *addr);
-
- BUG_ON(page_count(virt_to_page(ptep)) == 0);
- if (page_count(virt_to_page(ptep)) == 1)
- return 0;
-
- pud_clear(pud);
- put_page(virt_to_page(ptep));
- *addr = ALIGN(*addr, HPAGE_SIZE * PTRS_PER_PTE) - HPAGE_SIZE;
- return 1;
-}
-
-pte_t *huge_pte_alloc(struct mm_struct *mm,
- unsigned long addr, unsigned long sz)
-{
- pgd_t *pgd;
- pud_t *pud;
- pte_t *pte = NULL;
-
- pgd = pgd_offset(mm, addr);
- pud = pud_alloc(mm, pgd, addr);
- if (pud) {
- if (sz == PUD_SIZE) {
- pte = (pte_t *)pud;
- } else {
- BUG_ON(sz != PMD_SIZE);
- if (pud_none(*pud))
- pte = huge_pmd_share(mm, addr, pud);
- else
- pte = (pte_t *)pmd_alloc(mm, pud, addr);
- }
- }
- BUG_ON(pte && !pte_none(*pte) && !pte_huge(*pte));
-
- return pte;
-}
-
-pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
-{
- pgd_t *pgd;
- pud_t *pud;
- pmd_t *pmd = NULL;
-
- pgd = pgd_offset(mm, addr);
- if (pgd_present(*pgd)) {
- pud = pud_offset(pgd, addr);
- if (pud_present(*pud)) {
- if (pud_large(*pud))
- return (pte_t *)pud;
- pmd = pmd_offset(pud, addr);
- }
- }
- return (pte_t *) pmd;
-}
-
#if 0 /* This is just for testing */
struct page *
follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
return !!(pud_val(pud) & _PAGE_PSE);
}
-struct page *
-follow_huge_pmd(struct mm_struct *mm, unsigned long address,
- pmd_t *pmd, int write)
-{
- struct page *page;
-
- page = pte_page(*(pte_t *)pmd);
- if (page)
- page += ((address & ~PMD_MASK) >> PAGE_SHIFT);
- return page;
-}
-
-struct page *
-follow_huge_pud(struct mm_struct *mm, unsigned long address,
- pud_t *pud, int write)
-{
- struct page *page;
-
- page = pte_page(*(pte_t *)pud);
- if (page)
- page += ((address & ~PUD_MASK) >> PAGE_SHIFT);
- return page;
-}
-
#endif
/* x86_64 also uses this file */
} while (0)
extern void split_huge_page_pmd_mm(struct mm_struct *mm, unsigned long address,
pmd_t *pmd);
-#if HPAGE_PMD_ORDER > MAX_ORDER
+#if HPAGE_PMD_ORDER >= MAX_ORDER
#error "hugepages can't be allocated by the buddy allocator"
#endif
extern int hugepage_madvise(struct vm_area_struct *vma,
int dequeue_hwpoisoned_huge_page(struct page *page);
void copy_huge_page(struct page *dst, struct page *src);
+#ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE
+pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud);
+#endif
+
extern unsigned long hugepages_treat_as_movable;
extern const unsigned long hugetlb_zero, hugetlb_infinity;
extern int sysctl_hugetlb_shm_group;
return ret;
}
-/* Can be overriden by architectures */
-__attribute__((weak)) struct page *
-follow_huge_pud(struct mm_struct *mm, unsigned long address,
- pud_t *pud, int write)
-{
- BUG();
- return NULL;
-}
-
long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
struct page **pages, struct vm_area_struct **vmas,
unsigned long *position, unsigned long *nr_pages,
hugetlb_acct_memory(h, -(chg - freed));
}
+#ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE
+static unsigned long page_table_shareable(struct vm_area_struct *svma,
+ struct vm_area_struct *vma,
+ unsigned long addr, pgoff_t idx)
+{
+ unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) +
+ svma->vm_start;
+ unsigned long sbase = saddr & PUD_MASK;
+ unsigned long s_end = sbase + PUD_SIZE;
+
+ /* Allow segments to share if only one is marked locked */
+ unsigned long vm_flags = vma->vm_flags & ~VM_LOCKED;
+ unsigned long svm_flags = svma->vm_flags & ~VM_LOCKED;
+
+ /*
+ * match the virtual addresses, permission and the alignment of the
+ * page table page.
+ */
+ if (pmd_index(addr) != pmd_index(saddr) ||
+ vm_flags != svm_flags ||
+ sbase < svma->vm_start || svma->vm_end < s_end)
+ return 0;
+
+ return saddr;
+}
+
+static int vma_shareable(struct vm_area_struct *vma, unsigned long addr)
+{
+ unsigned long base = addr & PUD_MASK;
+ unsigned long end = base + PUD_SIZE;
+
+ /*
+ * check on proper vm_flags and page table alignment
+ */
+ if (vma->vm_flags & VM_MAYSHARE &&
+ vma->vm_start <= base && end <= vma->vm_end)
+ return 1;
+ return 0;
+}
+
+/*
+ * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc()
+ * and returns the corresponding pte. While this is not necessary for the
+ * !shared pmd case because we can allocate the pmd later as well, it makes the
+ * code much cleaner. pmd allocation is essential for the shared case because
+ * pud has to be populated inside the same i_mmap_mutex section - otherwise
+ * racing tasks could either miss the sharing (see huge_pte_offset) or select a
+ * bad pmd for sharing.
+ */
+pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
+{
+ struct vm_area_struct *vma = find_vma(mm, addr);
+ struct address_space *mapping = vma->vm_file->f_mapping;
+ pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) +
+ vma->vm_pgoff;
+ struct vm_area_struct *svma;
+ unsigned long saddr;
+ pte_t *spte = NULL;
+ pte_t *pte;
+
+ if (!vma_shareable(vma, addr))
+ return (pte_t *)pmd_alloc(mm, pud, addr);
+
+ mutex_lock(&mapping->i_mmap_mutex);
+ vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) {
+ if (svma == vma)
+ continue;
+
+ saddr = page_table_shareable(svma, vma, addr, idx);
+ if (saddr) {
+ spte = huge_pte_offset(svma->vm_mm, saddr);
+ if (spte) {
+ get_page(virt_to_page(spte));
+ break;
+ }
+ }
+ }
+
+ if (!spte)
+ goto out;
+
+ spin_lock(&mm->page_table_lock);
+ if (pud_none(*pud))
+ pud_populate(mm, pud,
+ (pmd_t *)((unsigned long)spte & PAGE_MASK));
+ else
+ put_page(virt_to_page(spte));
+ spin_unlock(&mm->page_table_lock);
+out:
+ pte = (pte_t *)pmd_alloc(mm, pud, addr);
+ mutex_unlock(&mapping->i_mmap_mutex);
+ return pte;
+}
+
+/*
+ * unmap huge page backed by shared pte.
+ *
+ * Hugetlb pte page is ref counted at the time of mapping. If pte is shared
+ * indicated by page_count > 1, unmap is achieved by clearing pud and
+ * decrementing the ref count. If count == 1, the pte page is not shared.
+ *
+ * called with vma->vm_mm->page_table_lock held.
+ *
+ * returns: 1 successfully unmapped a shared pte page
+ * 0 the underlying pte page is not shared, or it is the last user
+ */
+int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
+{
+ pgd_t *pgd = pgd_offset(mm, *addr);
+ pud_t *pud = pud_offset(pgd, *addr);
+
+ BUG_ON(page_count(virt_to_page(ptep)) == 0);
+ if (page_count(virt_to_page(ptep)) == 1)
+ return 0;
+
+ pud_clear(pud);
+ put_page(virt_to_page(ptep));
+ *addr = ALIGN(*addr, HPAGE_SIZE * PTRS_PER_PTE) - HPAGE_SIZE;
+ return 1;
+}
+#define want_pmd_share() (1)
+#else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */
+pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
+{
+ return NULL;
+}
+#define want_pmd_share() (0)
+#endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */
+
+#ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB
+pte_t *huge_pte_alloc(struct mm_struct *mm,
+ unsigned long addr, unsigned long sz)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pte_t *pte = NULL;
+
+ pgd = pgd_offset(mm, addr);
+ pud = pud_alloc(mm, pgd, addr);
+ if (pud) {
+ if (sz == PUD_SIZE) {
+ pte = (pte_t *)pud;
+ } else {
+ BUG_ON(sz != PMD_SIZE);
+ if (want_pmd_share() && pud_none(*pud))
+ pte = huge_pmd_share(mm, addr, pud);
+ else
+ pte = (pte_t *)pmd_alloc(mm, pud, addr);
+ }
+ }
+ BUG_ON(pte && !pte_none(*pte) && !pte_huge(*pte));
+
+ return pte;
+}
+
+pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd = NULL;
+
+ pgd = pgd_offset(mm, addr);
+ if (pgd_present(*pgd)) {
+ pud = pud_offset(pgd, addr);
+ if (pud_present(*pud)) {
+ if (pud_huge(*pud))
+ return (pte_t *)pud;
+ pmd = pmd_offset(pud, addr);
+ }
+ }
+ return (pte_t *) pmd;
+}
+
+struct page *
+follow_huge_pmd(struct mm_struct *mm, unsigned long address,
+ pmd_t *pmd, int write)
+{
+ struct page *page;
+
+ page = pte_page(*(pte_t *)pmd);
+ if (page)
+ page += ((address & ~PMD_MASK) >> PAGE_SHIFT);
+ return page;
+}
+
+struct page *
+follow_huge_pud(struct mm_struct *mm, unsigned long address,
+ pud_t *pud, int write)
+{
+ struct page *page;
+
+ page = pte_page(*(pte_t *)pud);
+ if (page)
+ page += ((address & ~PUD_MASK) >> PAGE_SHIFT);
+ return page;
+}
+
+#else /* !CONFIG_ARCH_WANT_GENERAL_HUGETLB */
+
+/* Can be overriden by architectures */
+__attribute__((weak)) struct page *
+follow_huge_pud(struct mm_struct *mm, unsigned long address,
+ pud_t *pud, int write)
+{
+ BUG();
+ return NULL;
+}
+
+#endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */
+
#ifdef CONFIG_MEMORY_FAILURE
/* Should be called in hugetlb_lock */
projects / ~andy / linux / commitdiff