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authorSrikant Patnaik2015-01-11 12:28:04 +0530
committerSrikant Patnaik2015-01-11 12:28:04 +0530
commit871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch)
tree8718f573808810c2a1e8cb8fb6ac469093ca2784 /arch/x86/mm/pgtable.c
parent9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff)
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure.
Diffstat (limited to 'arch/x86/mm/pgtable.c')
-rw-r--r--arch/x86/mm/pgtable.c447
1 files changed, 447 insertions, 0 deletions
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
new file mode 100644
index 00000000..8573b83a
--- /dev/null
+++ b/arch/x86/mm/pgtable.c
@@ -0,0 +1,447 @@
+#include <linux/mm.h>
+#include <linux/gfp.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
+#include <asm/tlb.h>
+#include <asm/fixmap.h>
+
+#define PGALLOC_GFP GFP_KERNEL | __GFP_NOTRACK | __GFP_REPEAT | __GFP_ZERO
+
+#ifdef CONFIG_HIGHPTE
+#define PGALLOC_USER_GFP __GFP_HIGHMEM
+#else
+#define PGALLOC_USER_GFP 0
+#endif
+
+gfp_t __userpte_alloc_gfp = PGALLOC_GFP | PGALLOC_USER_GFP;
+
+pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
+{
+ return (pte_t *)__get_free_page(PGALLOC_GFP);
+}
+
+pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address)
+{
+ struct page *pte;
+
+ pte = alloc_pages(__userpte_alloc_gfp, 0);
+ if (pte)
+ pgtable_page_ctor(pte);
+ return pte;
+}
+
+static int __init setup_userpte(char *arg)
+{
+ if (!arg)
+ return -EINVAL;
+
+ /*
+ * "userpte=nohigh" disables allocation of user pagetables in
+ * high memory.
+ */
+ if (strcmp(arg, "nohigh") == 0)
+ __userpte_alloc_gfp &= ~__GFP_HIGHMEM;
+ else
+ return -EINVAL;
+ return 0;
+}
+early_param("userpte", setup_userpte);
+
+void ___pte_free_tlb(struct mmu_gather *tlb, struct page *pte)
+{
+ pgtable_page_dtor(pte);
+ paravirt_release_pte(page_to_pfn(pte));
+ tlb_remove_page(tlb, pte);
+}
+
+#if PAGETABLE_LEVELS > 2
+void ___pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd)
+{
+ paravirt_release_pmd(__pa(pmd) >> PAGE_SHIFT);
+ tlb_remove_page(tlb, virt_to_page(pmd));
+}
+
+#if PAGETABLE_LEVELS > 3
+void ___pud_free_tlb(struct mmu_gather *tlb, pud_t *pud)
+{
+ paravirt_release_pud(__pa(pud) >> PAGE_SHIFT);
+ tlb_remove_page(tlb, virt_to_page(pud));
+}
+#endif /* PAGETABLE_LEVELS > 3 */
+#endif /* PAGETABLE_LEVELS > 2 */
+
+static inline void pgd_list_add(pgd_t *pgd)
+{
+ struct page *page = virt_to_page(pgd);
+
+ list_add(&page->lru, &pgd_list);
+}
+
+static inline void pgd_list_del(pgd_t *pgd)
+{
+ struct page *page = virt_to_page(pgd);
+
+ list_del(&page->lru);
+}
+
+#define UNSHARED_PTRS_PER_PGD \
+ (SHARED_KERNEL_PMD ? KERNEL_PGD_BOUNDARY : PTRS_PER_PGD)
+
+
+static void pgd_set_mm(pgd_t *pgd, struct mm_struct *mm)
+{
+ BUILD_BUG_ON(sizeof(virt_to_page(pgd)->index) < sizeof(mm));
+ virt_to_page(pgd)->index = (pgoff_t)mm;
+}
+
+struct mm_struct *pgd_page_get_mm(struct page *page)
+{
+ return (struct mm_struct *)page->index;
+}
+
+static void pgd_ctor(struct mm_struct *mm, pgd_t *pgd)
+{
+ /* If the pgd points to a shared pagetable level (either the
+ ptes in non-PAE, or shared PMD in PAE), then just copy the
+ references from swapper_pg_dir. */
+ if (PAGETABLE_LEVELS == 2 ||
+ (PAGETABLE_LEVELS == 3 && SHARED_KERNEL_PMD) ||
+ PAGETABLE_LEVELS == 4) {
+ clone_pgd_range(pgd + KERNEL_PGD_BOUNDARY,
+ swapper_pg_dir + KERNEL_PGD_BOUNDARY,
+ KERNEL_PGD_PTRS);
+ }
+
+ /* list required to sync kernel mapping updates */
+ if (!SHARED_KERNEL_PMD) {
+ pgd_set_mm(pgd, mm);
+ pgd_list_add(pgd);
+ }
+}
+
+static void pgd_dtor(pgd_t *pgd)
+{
+ if (SHARED_KERNEL_PMD)
+ return;
+
+ spin_lock(&pgd_lock);
+ pgd_list_del(pgd);
+ spin_unlock(&pgd_lock);
+}
+
+/*
+ * List of all pgd's needed for non-PAE so it can invalidate entries
+ * in both cached and uncached pgd's; not needed for PAE since the
+ * kernel pmd is shared. If PAE were not to share the pmd a similar
+ * tactic would be needed. This is essentially codepath-based locking
+ * against pageattr.c; it is the unique case in which a valid change
+ * of kernel pagetables can't be lazily synchronized by vmalloc faults.
+ * vmalloc faults work because attached pagetables are never freed.
+ * -- wli
+ */
+
+#ifdef CONFIG_X86_PAE
+/*
+ * In PAE mode, we need to do a cr3 reload (=tlb flush) when
+ * updating the top-level pagetable entries to guarantee the
+ * processor notices the update. Since this is expensive, and
+ * all 4 top-level entries are used almost immediately in a
+ * new process's life, we just pre-populate them here.
+ *
+ * Also, if we're in a paravirt environment where the kernel pmd is
+ * not shared between pagetables (!SHARED_KERNEL_PMDS), we allocate
+ * and initialize the kernel pmds here.
+ */
+#define PREALLOCATED_PMDS UNSHARED_PTRS_PER_PGD
+
+void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmd)
+{
+ paravirt_alloc_pmd(mm, __pa(pmd) >> PAGE_SHIFT);
+
+ /* Note: almost everything apart from _PAGE_PRESENT is
+ reserved at the pmd (PDPT) level. */
+ set_pud(pudp, __pud(__pa(pmd) | _PAGE_PRESENT));
+
+ /*
+ * According to Intel App note "TLBs, Paging-Structure Caches,
+ * and Their Invalidation", April 2007, document 317080-001,
+ * section 8.1: in PAE mode we explicitly have to flush the
+ * TLB via cr3 if the top-level pgd is changed...
+ */
+ flush_tlb_mm(mm);
+}
+#else /* !CONFIG_X86_PAE */
+
+/* No need to prepopulate any pagetable entries in non-PAE modes. */
+#define PREALLOCATED_PMDS 0
+
+#endif /* CONFIG_X86_PAE */
+
+static void free_pmds(pmd_t *pmds[])
+{
+ int i;
+
+ for(i = 0; i < PREALLOCATED_PMDS; i++)
+ if (pmds[i])
+ free_page((unsigned long)pmds[i]);
+}
+
+static int preallocate_pmds(pmd_t *pmds[])
+{
+ int i;
+ bool failed = false;
+
+ for(i = 0; i < PREALLOCATED_PMDS; i++) {
+ pmd_t *pmd = (pmd_t *)__get_free_page(PGALLOC_GFP);
+ if (pmd == NULL)
+ failed = true;
+ pmds[i] = pmd;
+ }
+
+ if (failed) {
+ free_pmds(pmds);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+/*
+ * Mop up any pmd pages which may still be attached to the pgd.
+ * Normally they will be freed by munmap/exit_mmap, but any pmd we
+ * preallocate which never got a corresponding vma will need to be
+ * freed manually.
+ */
+static void pgd_mop_up_pmds(struct mm_struct *mm, pgd_t *pgdp)
+{
+ int i;
+
+ for(i = 0; i < PREALLOCATED_PMDS; i++) {
+ pgd_t pgd = pgdp[i];
+
+ if (pgd_val(pgd) != 0) {
+ pmd_t *pmd = (pmd_t *)pgd_page_vaddr(pgd);
+
+ pgdp[i] = native_make_pgd(0);
+
+ paravirt_release_pmd(pgd_val(pgd) >> PAGE_SHIFT);
+ pmd_free(mm, pmd);
+ }
+ }
+}
+
+static void pgd_prepopulate_pmd(struct mm_struct *mm, pgd_t *pgd, pmd_t *pmds[])
+{
+ pud_t *pud;
+ unsigned long addr;
+ int i;
+
+ if (PREALLOCATED_PMDS == 0) /* Work around gcc-3.4.x bug */
+ return;
+
+ pud = pud_offset(pgd, 0);
+
+ for (addr = i = 0; i < PREALLOCATED_PMDS;
+ i++, pud++, addr += PUD_SIZE) {
+ pmd_t *pmd = pmds[i];
+
+ if (i >= KERNEL_PGD_BOUNDARY)
+ memcpy(pmd, (pmd_t *)pgd_page_vaddr(swapper_pg_dir[i]),
+ sizeof(pmd_t) * PTRS_PER_PMD);
+
+ pud_populate(mm, pud, pmd);
+ }
+}
+
+pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+ pgd_t *pgd;
+ pmd_t *pmds[PREALLOCATED_PMDS];
+
+ pgd = (pgd_t *)__get_free_page(PGALLOC_GFP);
+
+ if (pgd == NULL)
+ goto out;
+
+ mm->pgd = pgd;
+
+ if (preallocate_pmds(pmds) != 0)
+ goto out_free_pgd;
+
+ if (paravirt_pgd_alloc(mm) != 0)
+ goto out_free_pmds;
+
+ /*
+ * Make sure that pre-populating the pmds is atomic with
+ * respect to anything walking the pgd_list, so that they
+ * never see a partially populated pgd.
+ */
+ spin_lock(&pgd_lock);
+
+ pgd_ctor(mm, pgd);
+ pgd_prepopulate_pmd(mm, pgd, pmds);
+
+ spin_unlock(&pgd_lock);
+
+ return pgd;
+
+out_free_pmds:
+ free_pmds(pmds);
+out_free_pgd:
+ free_page((unsigned long)pgd);
+out:
+ return NULL;
+}
+
+void pgd_free(struct mm_struct *mm, pgd_t *pgd)
+{
+ pgd_mop_up_pmds(mm, pgd);
+ pgd_dtor(pgd);
+ paravirt_pgd_free(mm, pgd);
+ free_page((unsigned long)pgd);
+}
+
+int ptep_set_access_flags(struct vm_area_struct *vma,
+ unsigned long address, pte_t *ptep,
+ pte_t entry, int dirty)
+{
+ int changed = !pte_same(*ptep, entry);
+
+ if (changed && dirty) {
+ *ptep = entry;
+ pte_update_defer(vma->vm_mm, address, ptep);
+ flush_tlb_page(vma, address);
+ }
+
+ return changed;
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+int pmdp_set_access_flags(struct vm_area_struct *vma,
+ unsigned long address, pmd_t *pmdp,
+ pmd_t entry, int dirty)
+{
+ int changed = !pmd_same(*pmdp, entry);
+
+ VM_BUG_ON(address & ~HPAGE_PMD_MASK);
+
+ if (changed && dirty) {
+ *pmdp = entry;
+ pmd_update_defer(vma->vm_mm, address, pmdp);
+ flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
+ }
+
+ return changed;
+}
+#endif
+
+int ptep_test_and_clear_young(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *ptep)
+{
+ int ret = 0;
+
+ if (pte_young(*ptep))
+ ret = test_and_clear_bit(_PAGE_BIT_ACCESSED,
+ (unsigned long *) &ptep->pte);
+
+ if (ret)
+ pte_update(vma->vm_mm, addr, ptep);
+
+ return ret;
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+int pmdp_test_and_clear_young(struct vm_area_struct *vma,
+ unsigned long addr, pmd_t *pmdp)
+{
+ int ret = 0;
+
+ if (pmd_young(*pmdp))
+ ret = test_and_clear_bit(_PAGE_BIT_ACCESSED,
+ (unsigned long *)pmdp);
+
+ if (ret)
+ pmd_update(vma->vm_mm, addr, pmdp);
+
+ return ret;
+}
+#endif
+
+int ptep_clear_flush_young(struct vm_area_struct *vma,
+ unsigned long address, pte_t *ptep)
+{
+ int young;
+
+ young = ptep_test_and_clear_young(vma, address, ptep);
+ if (young)
+ flush_tlb_page(vma, address);
+
+ return young;
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+int pmdp_clear_flush_young(struct vm_area_struct *vma,
+ unsigned long address, pmd_t *pmdp)
+{
+ int young;
+
+ VM_BUG_ON(address & ~HPAGE_PMD_MASK);
+
+ young = pmdp_test_and_clear_young(vma, address, pmdp);
+ if (young)
+ flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
+
+ return young;
+}
+
+void pmdp_splitting_flush(struct vm_area_struct *vma,
+ unsigned long address, pmd_t *pmdp)
+{
+ int set;
+ VM_BUG_ON(address & ~HPAGE_PMD_MASK);
+ set = !test_and_set_bit(_PAGE_BIT_SPLITTING,
+ (unsigned long *)pmdp);
+ if (set) {
+ pmd_update(vma->vm_mm, address, pmdp);
+ /* need tlb flush only to serialize against gup-fast */
+ flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
+ }
+}
+#endif
+
+/**
+ * reserve_top_address - reserves a hole in the top of kernel address space
+ * @reserve - size of hole to reserve
+ *
+ * Can be used to relocate the fixmap area and poke a hole in the top
+ * of kernel address space to make room for a hypervisor.
+ */
+void __init reserve_top_address(unsigned long reserve)
+{
+#ifdef CONFIG_X86_32
+ BUG_ON(fixmaps_set > 0);
+ printk(KERN_INFO "Reserving virtual address space above 0x%08x\n",
+ (int)-reserve);
+ __FIXADDR_TOP = -reserve - PAGE_SIZE;
+#endif
+}
+
+int fixmaps_set;
+
+void __native_set_fixmap(enum fixed_addresses idx, pte_t pte)
+{
+ unsigned long address = __fix_to_virt(idx);
+
+ if (idx >= __end_of_fixed_addresses) {
+ BUG();
+ return;
+ }
+ set_pte_vaddr(address, pte);
+ fixmaps_set++;
+}
+
+void native_set_fixmap(enum fixed_addresses idx, phys_addr_t phys,
+ pgprot_t flags)
+{
+ __native_set_fixmap(idx, pfn_pte(phys >> PAGE_SHIFT, flags));
+}