]> xenbits.xensource.com Git - people/aperard/linux-arndale.git/commitdiff
ARM: mm: HugeTLB support for LPAE systems.
authorCatalin Marinas <catalin.marinas@arm.com>
Wed, 25 Jul 2012 13:32:38 +0000 (14:32 +0100)
committerVasanth Ananthan <vasanthananthan@gmail.com>
Tue, 8 Jan 2013 10:34:47 +0000 (16:04 +0530)
This patch adds support for hugetlbfs based on the x86 implementation.
It allows mapping of 2MB sections (see Documentation/vm/hugetlbpage.txt
for usage). The 64K pages configuration is not supported (section size
is 512MB in this case).

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[steve.capper@arm.com: symbolic constants replace numbers in places.
Split up into multiple files, to simplify future non-LPAE support].
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Steve Capper <steve.capper@arm.com>
arch/arm/Kconfig
arch/arm/include/asm/hugetlb-3level.h [new file with mode: 0644]
arch/arm/include/asm/hugetlb.h [new file with mode: 0644]
arch/arm/include/asm/pgtable-3level.h
arch/arm/mm/Makefile
arch/arm/mm/dma-mapping.c
arch/arm/mm/hugetlbpage-3level.c [new file with mode: 0644]
arch/arm/mm/hugetlbpage.c [new file with mode: 0644]

index a36316cdb4284f1cca21c60aea558a91640d74e4..d15142963b77e17045957d5e736fe481fac0095e 100644 (file)
@@ -1784,6 +1784,10 @@ 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
+
 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 (file)
index 0000000..4868064
--- /dev/null
@@ -0,0 +1,61 @@
+/*
+ * 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
+
+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);
+}
+
+#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 (file)
index 0000000..7af9cf6
--- /dev/null
@@ -0,0 +1,83 @@
+/*
+ * 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/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 */
index f165e12389044de49a06b19789191b7ab75dca0c..18f8ae4044b1f693534ece61f85e63621b321d50 100644 (file)
 
 #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.
  *
@@ -154,6 +162,11 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
 
 #define set_pte_ext(ptep,pte,ext) cpu_set_pte_ext(ptep,__pte(pte_val(pte)|(ext)))
 
+#define pte_huge(pte)          ((pte_val(pte) & PMD_TYPE_MASK) == PMD_TYPE_SECT)
+
+#define pte_mkhuge(pte)                (__pte((pte_val(pte) & ~PMD_TYPE_MASK) | PMD_TYPE_SECT))
+
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_PGTABLE_3LEVEL_H */
index 8a9c4cb50a93f3309588af662d0863f86daf3aff..1560bbcad178750b0b003775d11a99e5e668d2c5 100644 (file)
@@ -16,6 +16,8 @@ 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_HUGETLB_PAGE)     += hugetlbpage-3level.o
 
 obj-$(CONFIG_CPU_ABRT_NOMMU)   += abort-nommu.o
 obj-$(CONFIG_CPU_ABRT_EV4)     += abort-ev4.o
index 58bc3e4d3bd0a76094d8a2a40c0be9bece4eaf7a..ab35ec229cdd6cd7cb298688f84ec058fba33886 100644 (file)
@@ -241,7 +241,7 @@ 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/hugetlbpage-3level.c b/arch/arm/mm/hugetlbpage-3level.c
new file mode 100644 (file)
index 0000000..86474f0
--- /dev/null
@@ -0,0 +1,190 @@
+/*
+ * arch/arm/mm/hugetlbpage-3level.c
+ *
+ * Copyright (C) 2002, Rohit Seth <rohit.seth@intel.com>
+ * Copyright (C) 2012 ARM 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>
+
+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.
+ */
+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) {
+               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;
+}
+
+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;
+}
diff --git a/arch/arm/mm/hugetlbpage.c b/arch/arm/mm/hugetlbpage.c
new file mode 100644 (file)
index 0000000..32fe7fd
--- /dev/null
@@ -0,0 +1,65 @@
+/*
+ * arch/arm/mm/hugetlbpage.c
+ *
+ * Copyright (C) 2002, Rohit Seth <rohit.seth@intel.com>
+ * Copyright (C) 2012 ARM 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>
+
+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 pmd_huge(pmd_t pmd)
+{
+       return (pmd_val(pmd) & PMD_TYPE_MASK) == PMD_TYPE_SECT;
+}
+
+int pud_huge(pud_t pud)
+{
+       return 0;
+}