aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorMark Brown <broonie@kernel.org>2014-10-08 21:39:12 +0100
committerMark Brown <broonie@kernel.org>2014-10-08 21:39:12 +0100
commit3e35197f71b84c5135cf92fcf15a66a80bf1ffbb (patch)
treebbff1e473dea20ff558c64d4fbd1774b962c404a
parent8bb495e3f02401ee6f76d1b1d77f3ac9f079e376 (diff)
parent3b132a8c46e7d0a95ceb75098aeeb06958fa7670 (diff)
downloadlinux-linaro-stable-v3.10/topic/thp.tar.gz
Merge tag 'arm-thp-for-lsk-v3.10-v1' of http://git.linaro.org/git-ro/people/christoffer.dall/linux-kvm-arm into lsk-v3.10-thpv3.10/topic/thp
ARM Transparent hugepages support for LSK v3.10 support
-rw-r--r--arch/arm/Kconfig8
-rw-r--r--arch/arm/include/asm/hugetlb-3level.h71
-rw-r--r--arch/arm/include/asm/hugetlb.h84
-rw-r--r--arch/arm/include/asm/pgtable-3level-hwdef.h4
-rw-r--r--arch/arm/include/asm/pgtable-3level.h88
-rw-r--r--arch/arm/include/asm/pgtable.h3
-rw-r--r--arch/arm/include/asm/tlb.h6
-rw-r--r--arch/arm/include/asm/tlbflush.h2
-rw-r--r--arch/arm/mm/Makefile1
-rw-r--r--arch/arm/mm/dma-mapping.c2
-rw-r--r--arch/arm/mm/flush.c25
-rw-r--r--arch/arm/mm/fsr-3level.c4
-rw-r--r--arch/arm/mm/hugetlbpage.c101
13 files changed, 386 insertions, 13 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 136f263..f6c0bc4 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1731,6 +1731,14 @@ config HW_PERF_EVENTS
Enable hardware performance counter support for perf events. If
disabled, perf events will use software events only.
+config SYS_SUPPORTS_HUGETLBFS
+ def_bool y
+ depends on ARM_LPAE
+
+config HAVE_ARCH_TRANSPARENT_HUGEPAGE
+ def_bool y
+ depends on ARM_LPAE
+
source "mm/Kconfig"
config FORCE_MAX_ZONEORDER
diff --git a/arch/arm/include/asm/hugetlb-3level.h b/arch/arm/include/asm/hugetlb-3level.h
new file mode 100644
index 0000000..d4014fb
--- /dev/null
+++ b/arch/arm/include/asm/hugetlb-3level.h
@@ -0,0 +1,71 @@
+/*
+ * arch/arm/include/asm/hugetlb-3level.h
+ *
+ * Copyright (C) 2012 ARM 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_ARM_HUGETLB_3LEVEL_H
+#define _ASM_ARM_HUGETLB_3LEVEL_H
+
+
+/*
+ * If our huge pte is non-zero then mark the valid bit.
+ * This allows pte_present(huge_ptep_get(ptep)) to return true for non-zero
+ * ptes.
+ * (The valid bit is automatically cleared by set_pte_at for PROT_NONE ptes).
+ */
+static inline pte_t huge_ptep_get(pte_t *ptep)
+{
+ pte_t retval = *ptep;
+ if (pte_val(retval))
+ pte_val(retval) |= L_PTE_VALID;
+ return retval;
+}
+
+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);
+}
+
+#endif /* _ASM_ARM_HUGETLB_3LEVEL_H */
diff --git a/arch/arm/include/asm/hugetlb.h b/arch/arm/include/asm/hugetlb.h
new file mode 100644
index 0000000..1f1b1cd
--- /dev/null
+++ b/arch/arm/include/asm/hugetlb.h
@@ -0,0 +1,84 @@
+/*
+ * arch/arm/include/asm/hugetlb.h
+ *
+ * Copyright (C) 2012 ARM 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_ARM_HUGETLB_H
+#define _ASM_ARM_HUGETLB_H
+
+#include <asm/page.h>
+#include <asm-generic/hugetlb.h>
+
+#include <asm/hugetlb-3level.h>
+
+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_ARM_HUGETLB_H */
diff --git a/arch/arm/include/asm/pgtable-3level-hwdef.h b/arch/arm/include/asm/pgtable-3level-hwdef.h
index 18f5cef..f088c86 100644
--- a/arch/arm/include/asm/pgtable-3level-hwdef.h
+++ b/arch/arm/include/asm/pgtable-3level-hwdef.h
@@ -30,6 +30,7 @@
#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)
#define PMD_BIT4 (_AT(pmdval_t, 0))
#define PMD_DOMAIN(x) (_AT(pmdval_t, 0))
#define PMD_APTABLE_SHIFT (61)
@@ -41,6 +42,8 @@
*/
#define PMD_SECT_BUFFERABLE (_AT(pmdval_t, 1) << 2)
#define PMD_SECT_CACHEABLE (_AT(pmdval_t, 1) << 3)
+#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)
@@ -66,6 +69,7 @@
#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_BUFFERABLE (_AT(pteval_t, 1) << 2) /* AttrIndx[0] */
#define PTE_CACHEABLE (_AT(pteval_t, 1) << 3) /* AttrIndx[1] */
#define PTE_EXT_SHARED (_AT(pteval_t, 3) << 8) /* SH[1:0], inner shareable */
diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h
index 86b8fe3..54733e5 100644
--- a/arch/arm/include/asm/pgtable-3level.h
+++ b/arch/arm/include/asm/pgtable-3level.h
@@ -62,6 +62,14 @@
#define USER_PTRS_PER_PGD (PAGE_OFFSET / PGDIR_SIZE)
/*
+ * Hugetlb definitions.
+ */
+#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)
+
+/*
* "Linux" PTE definitions for LPAE.
*
* These bits overlap with the hardware bits but the naming is preserved for
@@ -79,6 +87,11 @@
#define L_PTE_SPECIAL (_AT(pteval_t, 1) << 56) /* unused */
#define L_PTE_NONE (_AT(pteval_t, 1) << 57) /* PROT_NONE */
+#define PMD_SECT_VALID (_AT(pmdval_t, 1) << 0)
+#define PMD_SECT_DIRTY (_AT(pmdval_t, 1) << 55)
+#define PMD_SECT_SPLITTING (_AT(pmdval_t, 1) << 56)
+#define PMD_SECT_NONE (_AT(pmdval_t, 1) << 57)
+
/*
* To be used in assembly code with the upper page attributes.
*/
@@ -166,8 +179,83 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
clean_pmd_entry(pmdp); \
} while (0)
+/*
+ * For 3 levels of paging the PTE_EXT_NG bit will be set for user address ptes
+ * that are written to a page table but not for ptes created with mk_pte.
+ *
+ * In hugetlb_no_page, a new huge pte (new_pte) is generated and passed to
+ * hugetlb_cow, where it is compared with an entry in a page table.
+ * This comparison test fails erroneously leading ultimately to a memory leak.
+ *
+ * To correct this behaviour, we mask off PTE_EXT_NG for any pte that is
+ * present before running the comparison.
+ */
+#define __HAVE_ARCH_PTE_SAME
+#define pte_same(pte_a,pte_b) ((pte_present(pte_a) ? pte_val(pte_a) & ~PTE_EXT_NG \
+ : pte_val(pte_a)) \
+ == (pte_present(pte_b) ? pte_val(pte_b) & ~PTE_EXT_NG \
+ : pte_val(pte_b)))
+
#define set_pte_ext(ptep,pte,ext) cpu_set_pte_ext(ptep,__pte(pte_val(pte)|(ext)))
+#define pte_huge(pte) (pte_val(pte) && !(pte_val(pte) & PTE_TABLE_BIT))
+#define pte_mkhuge(pte) (__pte(pte_val(pte) & ~PTE_TABLE_BIT))
+
+#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);
+
+#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)
+
+/* represent a notpresent pmd by zero, this is used by pmdp_invalidate */
+#define pmd_mknotpresent(pmd) (__pmd(0))
+
+static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
+{
+ const pmdval_t mask = PMD_SECT_USER | PMD_SECT_XN | PMD_SECT_RDONLY |
+ PMD_SECT_VALID | PMD_SECT_NONE;
+ pmd_val(pmd) = (pmd_val(pmd) & ~mask) | (pgprot_val(newprot) & mask);
+ return pmd;
+}
+
+static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
+ pmd_t *pmdp, pmd_t pmd)
+{
+ BUG_ON(addr >= TASK_SIZE);
+
+ /* create a faulting entry if PROT_NONE protected */
+ if (pmd_val(pmd) & PMD_SECT_NONE)
+ pmd_val(pmd) &= ~PMD_SECT_VALID;
+
+ *pmdp = __pmd(pmd_val(pmd) | PMD_SECT_nG);
+ flush_pmd_entry(pmdp);
+}
+
+static inline int has_transparent_hugepage(void)
+{
+ return 1;
+}
+
#endif /* __ASSEMBLY__ */
#endif /* _ASM_PGTABLE_3LEVEL_H */
diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index 9bcd262..eaedce7 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -24,6 +24,9 @@
#include <asm/memory.h>
#include <asm/pgtable-hwdef.h>
+
+#include <asm/tlbflush.h>
+
#ifdef CONFIG_ARM_LPAE
#include <asm/pgtable-3level.h>
#else
diff --git a/arch/arm/include/asm/tlb.h b/arch/arm/include/asm/tlb.h
index bdf2b84..46e7cfb 100644
--- a/arch/arm/include/asm/tlb.h
+++ b/arch/arm/include/asm/tlb.h
@@ -204,6 +204,12 @@ static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp,
#endif
}
+static inline void
+tlb_remove_pmd_tlb_entry(struct mmu_gather *tlb, pmd_t *pmdp, unsigned long addr)
+{
+ tlb_add_flush(tlb, addr);
+}
+
#define pte_free_tlb(tlb, ptep, addr) __pte_free_tlb(tlb, ptep, addr)
#define pmd_free_tlb(tlb, pmdp, addr) __pmd_free_tlb(tlb, pmdp, addr)
#define pud_free_tlb(tlb, pudp, addr) pud_free((tlb)->mm, pudp)
diff --git a/arch/arm/include/asm/tlbflush.h b/arch/arm/include/asm/tlbflush.h
index a3625d1..c374592 100644
--- a/arch/arm/include/asm/tlbflush.h
+++ b/arch/arm/include/asm/tlbflush.h
@@ -535,6 +535,8 @@ static inline void update_mmu_cache(struct vm_area_struct *vma,
}
#endif
+#define update_mmu_cache_pmd(vma, address, pmd) do { } while (0)
+
#endif
#endif /* CONFIG_MMU */
diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile
index 9e51be9..224a9cc 100644
--- a/arch/arm/mm/Makefile
+++ b/arch/arm/mm/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_MODULES) += proc-syms.o
obj-$(CONFIG_ALIGNMENT_TRAP) += alignment.o
obj-$(CONFIG_HIGHMEM) += highmem.o
+obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_CPU_ABRT_NOMMU) += abort-nommu.o
obj-$(CONFIG_CPU_ABRT_EV4) += abort-ev4.o
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index ef3e0f3..9674476 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -250,7 +250,7 @@ static void __dma_free_buffer(struct page *page, size_t size)
#ifdef CONFIG_MMU
#ifdef CONFIG_HUGETLB_PAGE
-#error ARM Coherent DMA allocator does not (yet) support huge TLB
+#warning ARM Coherent DMA allocator does not (yet) support huge TLB
#endif
static void *__alloc_from_contiguous(struct device *dev, size_t size,
diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
index 32aa586..c9e37aa 100644
--- a/arch/arm/mm/flush.c
+++ b/arch/arm/mm/flush.c
@@ -17,6 +17,7 @@
#include <asm/highmem.h>
#include <asm/smp_plat.h>
#include <asm/tlbflush.h>
+#include <linux/hugetlb.h>
#include "mm.h"
@@ -168,19 +169,23 @@ void __flush_dcache_page(struct address_space *mapping, struct page *page)
* coherent with the kernels mapping.
*/
if (!PageHighMem(page)) {
- __cpuc_flush_dcache_area(page_address(page), PAGE_SIZE);
+ size_t page_size = PAGE_SIZE << compound_order(page);
+ __cpuc_flush_dcache_area(page_address(page), page_size);
} else {
- void *addr;
-
+ unsigned long i;
if (cache_is_vipt_nonaliasing()) {
- addr = kmap_atomic(page);
- __cpuc_flush_dcache_area(addr, PAGE_SIZE);
- kunmap_atomic(addr);
- } else {
- addr = kmap_high_get(page);
- if (addr) {
+ for (i = 0; i < (1 << compound_order(page)); i++) {
+ void *addr = kmap_atomic(page);
__cpuc_flush_dcache_area(addr, PAGE_SIZE);
- kunmap_high(page);
+ kunmap_atomic(addr);
+ }
+ } else {
+ for (i = 0; i < (1 << compound_order(page)); i++) {
+ void *addr = kmap_high_get(page);
+ if (addr) {
+ __cpuc_flush_dcache_area(addr, PAGE_SIZE);
+ kunmap_high(page);
+ }
}
}
}
diff --git a/arch/arm/mm/fsr-3level.c b/arch/arm/mm/fsr-3level.c
index 05a4e94..ab4409a 100644
--- a/arch/arm/mm/fsr-3level.c
+++ b/arch/arm/mm/fsr-3level.c
@@ -9,11 +9,11 @@ static struct fsr_info fsr_info[] = {
{ 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 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 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" },
diff --git a/arch/arm/mm/hugetlbpage.c b/arch/arm/mm/hugetlbpage.c
new file mode 100644
index 0000000..3d1e4a2
--- /dev/null
+++ b/arch/arm/mm/hugetlbpage.c
@@ -0,0 +1,101 @@
+/*
+ * arch/arm/mm/hugetlbpage.c
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * Based on arch/x86/include/asm/hugetlb.h and Bill Carson's patches
+ *
+ * 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>
+
+/*
+ * On ARM, huge pages are backed by pmd's rather than pte's, so we do a lot
+ * of type casting from pmd_t * to pte_t *.
+ */
+
+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))
+ pmd = pmd_offset(pud, addr);
+ }
+
+ return (pte_t *)pmd;
+}
+
+struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
+ int write)
+{
+ return ERR_PTR(-EINVAL);
+}
+
+int pud_huge(pud_t pud)
+{
+ return 0;
+}
+
+int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
+{
+ return 0;
+}
+
+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)
+ pte = (pte_t *)pmd_alloc(mm, pud, addr);
+
+ return pte;
+}
+
+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;
+}
+
+int pmd_huge(pmd_t pmd)
+{
+ return pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT);
+}