# Makefile for the linux i386-specific parts of the memory manager.
#
-obj-y := init_32.o pgtable.o fault.o ioremap_32.o extable_32.o pageattr.o mmap_32.o
+obj-y := init_32.o pgtable_32.o fault.o ioremap_32.o extable_32.o pageattr.o mmap_32.o
obj-$(CONFIG_NUMA) += discontig_32.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
+++ /dev/null
-/*
- * linux/arch/i386/mm/pgtable.c
- */
-
-#include <linux/sched.h>
-#include <linux/kernel.h>
-#include <linux/errno.h>
-#include <linux/mm.h>
-#include <linux/swap.h>
-#include <linux/smp.h>
-#include <linux/highmem.h>
-#include <linux/slab.h>
-#include <linux/pagemap.h>
-#include <linux/spinlock.h>
-#include <linux/module.h>
-#include <linux/quicklist.h>
-
-#include <asm/system.h>
-#include <asm/pgtable.h>
-#include <asm/pgalloc.h>
-#include <asm/fixmap.h>
-#include <asm/e820.h>
-#include <asm/tlb.h>
-#include <asm/tlbflush.h>
-
-void show_mem(void)
-{
- int total = 0, reserved = 0;
- int shared = 0, cached = 0;
- int highmem = 0;
- struct page *page;
- pg_data_t *pgdat;
- unsigned long i;
- unsigned long flags;
-
- printk(KERN_INFO "Mem-info:\n");
- show_free_areas();
- printk(KERN_INFO "Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
- for_each_online_pgdat(pgdat) {
- pgdat_resize_lock(pgdat, &flags);
- for (i = 0; i < pgdat->node_spanned_pages; ++i) {
- page = pgdat_page_nr(pgdat, i);
- total++;
- if (PageHighMem(page))
- highmem++;
- if (PageReserved(page))
- reserved++;
- else if (PageSwapCache(page))
- cached++;
- else if (page_count(page))
- shared += page_count(page) - 1;
- }
- pgdat_resize_unlock(pgdat, &flags);
- }
- printk(KERN_INFO "%d pages of RAM\n", total);
- printk(KERN_INFO "%d pages of HIGHMEM\n", highmem);
- printk(KERN_INFO "%d reserved pages\n", reserved);
- printk(KERN_INFO "%d pages shared\n", shared);
- printk(KERN_INFO "%d pages swap cached\n", cached);
-
- printk(KERN_INFO "%lu pages dirty\n", global_page_state(NR_FILE_DIRTY));
- printk(KERN_INFO "%lu pages writeback\n",
- global_page_state(NR_WRITEBACK));
- printk(KERN_INFO "%lu pages mapped\n", global_page_state(NR_FILE_MAPPED));
- printk(KERN_INFO "%lu pages slab\n",
- global_page_state(NR_SLAB_RECLAIMABLE) +
- global_page_state(NR_SLAB_UNRECLAIMABLE));
- printk(KERN_INFO "%lu pages pagetables\n",
- global_page_state(NR_PAGETABLE));
-}
-
-/*
- * Associate a virtual page frame with a given physical page frame
- * and protection flags for that frame.
- */
-static void set_pte_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
-{
- pgd_t *pgd;
- pud_t *pud;
- pmd_t *pmd;
- pte_t *pte;
-
- pgd = swapper_pg_dir + pgd_index(vaddr);
- if (pgd_none(*pgd)) {
- BUG();
- return;
- }
- pud = pud_offset(pgd, vaddr);
- if (pud_none(*pud)) {
- BUG();
- return;
- }
- pmd = pmd_offset(pud, vaddr);
- if (pmd_none(*pmd)) {
- BUG();
- return;
- }
- pte = pte_offset_kernel(pmd, vaddr);
- if (pgprot_val(flags))
- /* <pfn,flags> stored as-is, to permit clearing entries */
- set_pte(pte, pfn_pte(pfn, flags));
- else
- pte_clear(&init_mm, vaddr, pte);
-
- /*
- * It's enough to flush this one mapping.
- * (PGE mappings get flushed as well)
- */
- __flush_tlb_one(vaddr);
-}
-
-/*
- * Associate a large virtual page frame with a given physical page frame
- * and protection flags for that frame. pfn is for the base of the page,
- * vaddr is what the page gets mapped to - both must be properly aligned.
- * The pmd must already be instantiated. Assumes PAE mode.
- */
-void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
-{
- pgd_t *pgd;
- pud_t *pud;
- pmd_t *pmd;
-
- if (vaddr & (PMD_SIZE-1)) { /* vaddr is misaligned */
- printk(KERN_WARNING "set_pmd_pfn: vaddr misaligned\n");
- return; /* BUG(); */
- }
- if (pfn & (PTRS_PER_PTE-1)) { /* pfn is misaligned */
- printk(KERN_WARNING "set_pmd_pfn: pfn misaligned\n");
- return; /* BUG(); */
- }
- pgd = swapper_pg_dir + pgd_index(vaddr);
- if (pgd_none(*pgd)) {
- printk(KERN_WARNING "set_pmd_pfn: pgd_none\n");
- return; /* BUG(); */
- }
- pud = pud_offset(pgd, vaddr);
- pmd = pmd_offset(pud, vaddr);
- set_pmd(pmd, pfn_pmd(pfn, flags));
- /*
- * It's enough to flush this one mapping.
- * (PGE mappings get flushed as well)
- */
- __flush_tlb_one(vaddr);
-}
-
-static int fixmaps;
-unsigned long __FIXADDR_TOP = 0xfffff000;
-EXPORT_SYMBOL(__FIXADDR_TOP);
-
-void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t flags)
-{
- unsigned long address = __fix_to_virt(idx);
-
- if (idx >= __end_of_fixed_addresses) {
- BUG();
- return;
- }
- set_pte_pfn(address, phys >> PAGE_SHIFT, flags);
- fixmaps++;
-}
-
-/**
- * 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 reserve_top_address(unsigned long reserve)
-{
- BUG_ON(fixmaps > 0);
- printk(KERN_INFO "Reserving virtual address space above 0x%08x\n",
- (int)-reserve);
- __FIXADDR_TOP = -reserve - PAGE_SIZE;
- __VMALLOC_RESERVE += reserve;
-}
-
-pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
-{
- return (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
-}
-
-struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
-{
- struct page *pte;
-
-#ifdef CONFIG_HIGHPTE
- pte = alloc_pages(GFP_KERNEL|__GFP_HIGHMEM|__GFP_REPEAT|__GFP_ZERO, 0);
-#else
- pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
-#endif
- return pte;
-}
-
-void pmd_ctor(void *pmd, struct kmem_cache *cache, unsigned long flags)
-{
- memset(pmd, 0, PTRS_PER_PMD*sizeof(pmd_t));
-}
-
-/*
- * 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
- */
-DEFINE_SPINLOCK(pgd_lock);
-struct page *pgd_list;
-
-static inline void pgd_list_add(pgd_t *pgd)
-{
- struct page *page = virt_to_page(pgd);
- page->index = (unsigned long)pgd_list;
- if (pgd_list)
- set_page_private(pgd_list, (unsigned long)&page->index);
- pgd_list = page;
- set_page_private(page, (unsigned long)&pgd_list);
-}
-
-static inline void pgd_list_del(pgd_t *pgd)
-{
- struct page *next, **pprev, *page = virt_to_page(pgd);
- next = (struct page *)page->index;
- pprev = (struct page **)page_private(page);
- *pprev = next;
- if (next)
- set_page_private(next, (unsigned long)pprev);
-}
-
-
-
-#if (PTRS_PER_PMD == 1)
-/* Non-PAE pgd constructor */
-static void pgd_ctor(void *pgd)
-{
- unsigned long flags;
-
- /* !PAE, no pagetable sharing */
- memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
-
- spin_lock_irqsave(&pgd_lock, flags);
-
- /* must happen under lock */
- clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD,
- swapper_pg_dir + USER_PTRS_PER_PGD,
- KERNEL_PGD_PTRS);
- paravirt_alloc_pd_clone(__pa(pgd) >> PAGE_SHIFT,
- __pa(swapper_pg_dir) >> PAGE_SHIFT,
- USER_PTRS_PER_PGD,
- KERNEL_PGD_PTRS);
- pgd_list_add(pgd);
- spin_unlock_irqrestore(&pgd_lock, flags);
-}
-#else /* PTRS_PER_PMD > 1 */
-/* PAE pgd constructor */
-static void pgd_ctor(void *pgd)
-{
- /* PAE, kernel PMD may be shared */
-
- if (SHARED_KERNEL_PMD) {
- clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD,
- swapper_pg_dir + USER_PTRS_PER_PGD,
- KERNEL_PGD_PTRS);
- } else {
- unsigned long flags;
-
- memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
- spin_lock_irqsave(&pgd_lock, flags);
- pgd_list_add(pgd);
- spin_unlock_irqrestore(&pgd_lock, flags);
- }
-}
-#endif /* PTRS_PER_PMD */
-
-static void pgd_dtor(void *pgd)
-{
- unsigned long flags; /* can be called from interrupt context */
-
- if (SHARED_KERNEL_PMD)
- return;
-
- paravirt_release_pd(__pa(pgd) >> PAGE_SHIFT);
- spin_lock_irqsave(&pgd_lock, flags);
- pgd_list_del(pgd);
- spin_unlock_irqrestore(&pgd_lock, flags);
-}
-
-#define UNSHARED_PTRS_PER_PGD \
- (SHARED_KERNEL_PMD ? USER_PTRS_PER_PGD : PTRS_PER_PGD)
-
-/* If we allocate a pmd for part of the kernel address space, then
- make sure its initialized with the appropriate kernel mappings.
- Otherwise use a cached zeroed pmd. */
-static pmd_t *pmd_cache_alloc(int idx)
-{
- pmd_t *pmd;
-
- if (idx >= USER_PTRS_PER_PGD) {
- pmd = (pmd_t *)__get_free_page(GFP_KERNEL);
-
- if (pmd)
- memcpy(pmd,
- (void *)pgd_page_vaddr(swapper_pg_dir[idx]),
- sizeof(pmd_t) * PTRS_PER_PMD);
- } else
- pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL);
-
- return pmd;
-}
-
-static void pmd_cache_free(pmd_t *pmd, int idx)
-{
- if (idx >= USER_PTRS_PER_PGD)
- free_page((unsigned long)pmd);
- else
- kmem_cache_free(pmd_cache, pmd);
-}
-
-pgd_t *pgd_alloc(struct mm_struct *mm)
-{
- int i;
- pgd_t *pgd = quicklist_alloc(0, GFP_KERNEL, pgd_ctor);
-
- if (PTRS_PER_PMD == 1 || !pgd)
- return pgd;
-
- for (i = 0; i < UNSHARED_PTRS_PER_PGD; ++i) {
- pmd_t *pmd = pmd_cache_alloc(i);
-
- if (!pmd)
- goto out_oom;
-
- paravirt_alloc_pd(__pa(pmd) >> PAGE_SHIFT);
- set_pgd(&pgd[i], __pgd(1 + __pa(pmd)));
- }
- return pgd;
-
-out_oom:
- for (i--; i >= 0; i--) {
- pgd_t pgdent = pgd[i];
- void* pmd = (void *)__va(pgd_val(pgdent)-1);
- paravirt_release_pd(__pa(pmd) >> PAGE_SHIFT);
- pmd_cache_free(pmd, i);
- }
- quicklist_free(0, pgd_dtor, pgd);
- return NULL;
-}
-
-void pgd_free(pgd_t *pgd)
-{
- int i;
-
- /* in the PAE case user pgd entries are overwritten before usage */
- if (PTRS_PER_PMD > 1)
- for (i = 0; i < UNSHARED_PTRS_PER_PGD; ++i) {
- pgd_t pgdent = pgd[i];
- void* pmd = (void *)__va(pgd_val(pgdent)-1);
- paravirt_release_pd(__pa(pmd) >> PAGE_SHIFT);
- pmd_cache_free(pmd, i);
- }
- /* in the non-PAE case, free_pgtables() clears user pgd entries */
- quicklist_free(0, pgd_dtor, pgd);
-}
-
-void check_pgt_cache(void)
-{
- quicklist_trim(0, pgd_dtor, 25, 16);
-}
-
--- /dev/null
+/*
+ * linux/arch/i386/mm/pgtable.c
+ */
+
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/smp.h>
+#include <linux/highmem.h>
+#include <linux/slab.h>
+#include <linux/pagemap.h>
+#include <linux/spinlock.h>
+#include <linux/module.h>
+#include <linux/quicklist.h>
+
+#include <asm/system.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/fixmap.h>
+#include <asm/e820.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+
+void show_mem(void)
+{
+ int total = 0, reserved = 0;
+ int shared = 0, cached = 0;
+ int highmem = 0;
+ struct page *page;
+ pg_data_t *pgdat;
+ unsigned long i;
+ unsigned long flags;
+
+ printk(KERN_INFO "Mem-info:\n");
+ show_free_areas();
+ printk(KERN_INFO "Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
+ for_each_online_pgdat(pgdat) {
+ pgdat_resize_lock(pgdat, &flags);
+ for (i = 0; i < pgdat->node_spanned_pages; ++i) {
+ page = pgdat_page_nr(pgdat, i);
+ total++;
+ if (PageHighMem(page))
+ highmem++;
+ if (PageReserved(page))
+ reserved++;
+ else if (PageSwapCache(page))
+ cached++;
+ else if (page_count(page))
+ shared += page_count(page) - 1;
+ }
+ pgdat_resize_unlock(pgdat, &flags);
+ }
+ printk(KERN_INFO "%d pages of RAM\n", total);
+ printk(KERN_INFO "%d pages of HIGHMEM\n", highmem);
+ printk(KERN_INFO "%d reserved pages\n", reserved);
+ printk(KERN_INFO "%d pages shared\n", shared);
+ printk(KERN_INFO "%d pages swap cached\n", cached);
+
+ printk(KERN_INFO "%lu pages dirty\n", global_page_state(NR_FILE_DIRTY));
+ printk(KERN_INFO "%lu pages writeback\n",
+ global_page_state(NR_WRITEBACK));
+ printk(KERN_INFO "%lu pages mapped\n", global_page_state(NR_FILE_MAPPED));
+ printk(KERN_INFO "%lu pages slab\n",
+ global_page_state(NR_SLAB_RECLAIMABLE) +
+ global_page_state(NR_SLAB_UNRECLAIMABLE));
+ printk(KERN_INFO "%lu pages pagetables\n",
+ global_page_state(NR_PAGETABLE));
+}
+
+/*
+ * Associate a virtual page frame with a given physical page frame
+ * and protection flags for that frame.
+ */
+static void set_pte_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte;
+
+ pgd = swapper_pg_dir + pgd_index(vaddr);
+ if (pgd_none(*pgd)) {
+ BUG();
+ return;
+ }
+ pud = pud_offset(pgd, vaddr);
+ if (pud_none(*pud)) {
+ BUG();
+ return;
+ }
+ pmd = pmd_offset(pud, vaddr);
+ if (pmd_none(*pmd)) {
+ BUG();
+ return;
+ }
+ pte = pte_offset_kernel(pmd, vaddr);
+ if (pgprot_val(flags))
+ /* <pfn,flags> stored as-is, to permit clearing entries */
+ set_pte(pte, pfn_pte(pfn, flags));
+ else
+ pte_clear(&init_mm, vaddr, pte);
+
+ /*
+ * It's enough to flush this one mapping.
+ * (PGE mappings get flushed as well)
+ */
+ __flush_tlb_one(vaddr);
+}
+
+/*
+ * Associate a large virtual page frame with a given physical page frame
+ * and protection flags for that frame. pfn is for the base of the page,
+ * vaddr is what the page gets mapped to - both must be properly aligned.
+ * The pmd must already be instantiated. Assumes PAE mode.
+ */
+void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+
+ if (vaddr & (PMD_SIZE-1)) { /* vaddr is misaligned */
+ printk(KERN_WARNING "set_pmd_pfn: vaddr misaligned\n");
+ return; /* BUG(); */
+ }
+ if (pfn & (PTRS_PER_PTE-1)) { /* pfn is misaligned */
+ printk(KERN_WARNING "set_pmd_pfn: pfn misaligned\n");
+ return; /* BUG(); */
+ }
+ pgd = swapper_pg_dir + pgd_index(vaddr);
+ if (pgd_none(*pgd)) {
+ printk(KERN_WARNING "set_pmd_pfn: pgd_none\n");
+ return; /* BUG(); */
+ }
+ pud = pud_offset(pgd, vaddr);
+ pmd = pmd_offset(pud, vaddr);
+ set_pmd(pmd, pfn_pmd(pfn, flags));
+ /*
+ * It's enough to flush this one mapping.
+ * (PGE mappings get flushed as well)
+ */
+ __flush_tlb_one(vaddr);
+}
+
+static int fixmaps;
+unsigned long __FIXADDR_TOP = 0xfffff000;
+EXPORT_SYMBOL(__FIXADDR_TOP);
+
+void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t flags)
+{
+ unsigned long address = __fix_to_virt(idx);
+
+ if (idx >= __end_of_fixed_addresses) {
+ BUG();
+ return;
+ }
+ set_pte_pfn(address, phys >> PAGE_SHIFT, flags);
+ fixmaps++;
+}
+
+/**
+ * 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 reserve_top_address(unsigned long reserve)
+{
+ BUG_ON(fixmaps > 0);
+ printk(KERN_INFO "Reserving virtual address space above 0x%08x\n",
+ (int)-reserve);
+ __FIXADDR_TOP = -reserve - PAGE_SIZE;
+ __VMALLOC_RESERVE += reserve;
+}
+
+pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
+{
+ return (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
+}
+
+struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
+{
+ struct page *pte;
+
+#ifdef CONFIG_HIGHPTE
+ pte = alloc_pages(GFP_KERNEL|__GFP_HIGHMEM|__GFP_REPEAT|__GFP_ZERO, 0);
+#else
+ pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
+#endif
+ return pte;
+}
+
+void pmd_ctor(void *pmd, struct kmem_cache *cache, unsigned long flags)
+{
+ memset(pmd, 0, PTRS_PER_PMD*sizeof(pmd_t));
+}
+
+/*
+ * 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
+ */
+DEFINE_SPINLOCK(pgd_lock);
+struct page *pgd_list;
+
+static inline void pgd_list_add(pgd_t *pgd)
+{
+ struct page *page = virt_to_page(pgd);
+ page->index = (unsigned long)pgd_list;
+ if (pgd_list)
+ set_page_private(pgd_list, (unsigned long)&page->index);
+ pgd_list = page;
+ set_page_private(page, (unsigned long)&pgd_list);
+}
+
+static inline void pgd_list_del(pgd_t *pgd)
+{
+ struct page *next, **pprev, *page = virt_to_page(pgd);
+ next = (struct page *)page->index;
+ pprev = (struct page **)page_private(page);
+ *pprev = next;
+ if (next)
+ set_page_private(next, (unsigned long)pprev);
+}
+
+
+
+#if (PTRS_PER_PMD == 1)
+/* Non-PAE pgd constructor */
+static void pgd_ctor(void *pgd)
+{
+ unsigned long flags;
+
+ /* !PAE, no pagetable sharing */
+ memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
+
+ spin_lock_irqsave(&pgd_lock, flags);
+
+ /* must happen under lock */
+ clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD,
+ swapper_pg_dir + USER_PTRS_PER_PGD,
+ KERNEL_PGD_PTRS);
+ paravirt_alloc_pd_clone(__pa(pgd) >> PAGE_SHIFT,
+ __pa(swapper_pg_dir) >> PAGE_SHIFT,
+ USER_PTRS_PER_PGD,
+ KERNEL_PGD_PTRS);
+ pgd_list_add(pgd);
+ spin_unlock_irqrestore(&pgd_lock, flags);
+}
+#else /* PTRS_PER_PMD > 1 */
+/* PAE pgd constructor */
+static void pgd_ctor(void *pgd)
+{
+ /* PAE, kernel PMD may be shared */
+
+ if (SHARED_KERNEL_PMD) {
+ clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD,
+ swapper_pg_dir + USER_PTRS_PER_PGD,
+ KERNEL_PGD_PTRS);
+ } else {
+ unsigned long flags;
+
+ memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
+ spin_lock_irqsave(&pgd_lock, flags);
+ pgd_list_add(pgd);
+ spin_unlock_irqrestore(&pgd_lock, flags);
+ }
+}
+#endif /* PTRS_PER_PMD */
+
+static void pgd_dtor(void *pgd)
+{
+ unsigned long flags; /* can be called from interrupt context */
+
+ if (SHARED_KERNEL_PMD)
+ return;
+
+ paravirt_release_pd(__pa(pgd) >> PAGE_SHIFT);
+ spin_lock_irqsave(&pgd_lock, flags);
+ pgd_list_del(pgd);
+ spin_unlock_irqrestore(&pgd_lock, flags);
+}
+
+#define UNSHARED_PTRS_PER_PGD \
+ (SHARED_KERNEL_PMD ? USER_PTRS_PER_PGD : PTRS_PER_PGD)
+
+/* If we allocate a pmd for part of the kernel address space, then
+ make sure its initialized with the appropriate kernel mappings.
+ Otherwise use a cached zeroed pmd. */
+static pmd_t *pmd_cache_alloc(int idx)
+{
+ pmd_t *pmd;
+
+ if (idx >= USER_PTRS_PER_PGD) {
+ pmd = (pmd_t *)__get_free_page(GFP_KERNEL);
+
+ if (pmd)
+ memcpy(pmd,
+ (void *)pgd_page_vaddr(swapper_pg_dir[idx]),
+ sizeof(pmd_t) * PTRS_PER_PMD);
+ } else
+ pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL);
+
+ return pmd;
+}
+
+static void pmd_cache_free(pmd_t *pmd, int idx)
+{
+ if (idx >= USER_PTRS_PER_PGD)
+ free_page((unsigned long)pmd);
+ else
+ kmem_cache_free(pmd_cache, pmd);
+}
+
+pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+ int i;
+ pgd_t *pgd = quicklist_alloc(0, GFP_KERNEL, pgd_ctor);
+
+ if (PTRS_PER_PMD == 1 || !pgd)
+ return pgd;
+
+ for (i = 0; i < UNSHARED_PTRS_PER_PGD; ++i) {
+ pmd_t *pmd = pmd_cache_alloc(i);
+
+ if (!pmd)
+ goto out_oom;
+
+ paravirt_alloc_pd(__pa(pmd) >> PAGE_SHIFT);
+ set_pgd(&pgd[i], __pgd(1 + __pa(pmd)));
+ }
+ return pgd;
+
+out_oom:
+ for (i--; i >= 0; i--) {
+ pgd_t pgdent = pgd[i];
+ void* pmd = (void *)__va(pgd_val(pgdent)-1);
+ paravirt_release_pd(__pa(pmd) >> PAGE_SHIFT);
+ pmd_cache_free(pmd, i);
+ }
+ quicklist_free(0, pgd_dtor, pgd);
+ return NULL;
+}
+
+void pgd_free(pgd_t *pgd)
+{
+ int i;
+
+ /* in the PAE case user pgd entries are overwritten before usage */
+ if (PTRS_PER_PMD > 1)
+ for (i = 0; i < UNSHARED_PTRS_PER_PGD; ++i) {
+ pgd_t pgdent = pgd[i];
+ void* pmd = (void *)__va(pgd_val(pgdent)-1);
+ paravirt_release_pd(__pa(pmd) >> PAGE_SHIFT);
+ pmd_cache_free(pmd, i);
+ }
+ /* in the non-PAE case, free_pgtables() clears user pgd entries */
+ quicklist_free(0, pgd_dtor, pgd);
+}
+
+void check_pgt_cache(void)
+{
+ quicklist_trim(0, pgd_dtor, 25, 16);
+}
+
projects / GitHub / LineageOS / android_kernel_samsung_universal7580.git / commitdiff