include/asm-x86_64/pgalloc.h

   1 #ifndef _X86_64_PGALLOC_H
   2 #define _X86_64_PGALLOC_H
   3
   4 #include <asm/fixmap.h>
   5 #include <asm/pda.h>
   6 #include <linux/threads.h>
   7 #include <linux/mm.h>
   8
   9 #define pmd_populate_kernel(mm, pmd, pte) \
  10                 set_pmd(pmd, __pmd(_PAGE_TABLE | __pa(pte)))
  11 #define pud_populate(mm, pud, pmd) \
  12                 set_pud(pud, __pud(_PAGE_TABLE | __pa(pmd)))
  13 #define pgd_populate(mm, pgd, pud) \
  14                 set_pgd(pgd, __pgd(_PAGE_TABLE | __pa(pud)))
  15
  16 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd, struct page *pte)
  17 {
  18         set_pmd(pmd, __pmd(_PAGE_TABLE | (page_to_pfn(pte) << PAGE_SHIFT)));
  19 }
  20
  21 static inline pmd_t *get_pmd(void)
  22 {
  23         return (pmd_t *)get_zeroed_page(GFP_KERNEL);
  24 }
  25
  26 static inline void pmd_free(pmd_t *pmd)
  27 {
  28         BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
  29         free_page((unsigned long)pmd);
  30 }
  31
  32 static inline pmd_t *pmd_alloc_one (struct mm_struct *mm, unsigned long addr)
  33 {
  34         return (pmd_t *)get_zeroed_page(GFP_KERNEL|__GFP_REPEAT);
  35 }
  36
  37 static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
  38 {
  39         return (pud_t *)get_zeroed_page(GFP_KERNEL|__GFP_REPEAT);
  40 }
  41
  42 static inline void pud_free (pud_t *pud)
  43 {
  44         BUG_ON((unsigned long)pud & (PAGE_SIZE-1));
  45         free_page((unsigned long)pud);
  46 }
  47
  48 static inline void pgd_list_add(pgd_t *pgd)
  49 {
  50         struct page *page = virt_to_page(pgd);
  51
  52         spin_lock(&pgd_lock);
  53         page->index = (pgoff_t)pgd_list;
  54         if (pgd_list)
  55                 pgd_list->private = (unsigned long)&page->index;
  56         pgd_list = page;
  57         page->private = (unsigned long)&pgd_list;
  58         spin_unlock(&pgd_lock);
  59 }
  60
  61 static inline void pgd_list_del(pgd_t *pgd)
  62 {
  63         struct page *next, **pprev, *page = virt_to_page(pgd);
  64
  65         spin_lock(&pgd_lock);
  66         next = (struct page *)page->index;
  67         pprev = (struct page **)page->private;
  68         *pprev = next;
  69         if (next)
  70                 next->private = (unsigned long)pprev;
  71         spin_unlock(&pgd_lock);
  72 }
  73
  74 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
  75 {
  76         unsigned boundary;
  77         pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT);
  78         if (!pgd)
  79                 return NULL;
  80         pgd_list_add(pgd);
  81         /*
  82          * Copy kernel pointers in from init.
  83          * Could keep a freelist or slab cache of those because the kernel
  84          * part never changes.
  85          */
  86         boundary = pgd_index(__PAGE_OFFSET);
  87         memset(pgd, 0, boundary * sizeof(pgd_t));
  88         memcpy(pgd + boundary,
  89                init_level4_pgt + boundary,
  90                (PTRS_PER_PGD - boundary) * sizeof(pgd_t));
  91         return pgd;
  92 }
  93
  94 static inline void pgd_free(pgd_t *pgd)
  95 {
  96         BUG_ON((unsigned long)pgd & (PAGE_SIZE-1));
  97         pgd_list_del(pgd);
  98         free_page((unsigned long)pgd);
  99 }
 100
 101 static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
 102 {
 103         return (pte_t *)get_zeroed_page(GFP_KERNEL|__GFP_REPEAT);
 104 }
 105
 106 static inline struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
 107 {
 108         void *p = (void *)get_zeroed_page(GFP_KERNEL|__GFP_REPEAT);
 109         if (!p)
 110                 return NULL;
 111         return virt_to_page(p);
 112 }
 113
 114 /* Should really implement gc for free page table pages. This could be
 115    done with a reference count in struct page. */
 116
 117 static inline void pte_free_kernel(pte_t *pte)
 118 {
 119         BUG_ON((unsigned long)pte & (PAGE_SIZE-1));
 120         free_page((unsigned long)pte);
 121 }
 122
 123 static inline void pte_free(struct page *pte)
 124 {
 125         __free_page(pte);
 126 }
 127
 128 #define __pte_free_tlb(tlb,pte) tlb_remove_page((tlb),(pte))
 129
 130 #define __pmd_free_tlb(tlb,x)   tlb_remove_page((tlb),virt_to_page(x))
 131 #define __pud_free_tlb(tlb,x)   tlb_remove_page((tlb),virt_to_page(x))
 132
 133 #endif /* _X86_64_PGALLOC_H */