arch/alpha/mm/remap.c

   1 #include <linux/vmalloc.h>
   2 #include <asm/pgalloc.h>
   3 #include <asm/cacheflush.h>
   4
   5 /* called with the page_table_lock held */
   6 static inline void
   7 remap_area_pte(pte_t * pte, unsigned long address, unsigned long size,
   8                unsigned long phys_addr, unsigned long flags)
   9 {
  10         unsigned long end;
  11         unsigned long pfn;
  12
  13         address &= ~PMD_MASK;
  14         end = address + size;
  15         if (end > PMD_SIZE)
  16                 end = PMD_SIZE;
  17         if (address >= end)
  18                 BUG();
  19         pfn = phys_addr >> PAGE_SHIFT;
  20         do {
  21                 if (!pte_none(*pte)) {
  22                         printk("remap_area_pte: page already exists\n");
  23                         BUG();
  24                 }
  25                 set_pte(pte, pfn_pte(pfn,
  26                                      __pgprot(_PAGE_VALID | _PAGE_ASM |
  27                                               _PAGE_KRE | _PAGE_KWE | flags)));
  28                 address += PAGE_SIZE;
  29                 pfn++;
  30                 pte++;
  31         } while (address && (address < end));
  32 }
  33
  34 /* called with the page_table_lock held */
  35 static inline int
  36 remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size,
  37                unsigned long phys_addr, unsigned long flags)
  38 {
  39         unsigned long end;
  40
  41         address &= ~PGDIR_MASK;
  42         end = address + size;
  43         if (end > PGDIR_SIZE)
  44                 end = PGDIR_SIZE;
  45         phys_addr -= address;
  46         if (address >= end)
  47                 BUG();
  48         do {
  49                 pte_t * pte = pte_alloc_kernel(&init_mm, pmd, address);
  50                 if (!pte)
  51                         return -ENOMEM;
  52                 remap_area_pte(pte, address, end - address,
  53                                      address + phys_addr, flags);
  54                 address = (address + PMD_SIZE) & PMD_MASK;
  55                 pmd++;
  56         } while (address && (address < end));
  57         return 0;
  58 }
  59
  60 int
  61 __alpha_remap_area_pages(unsigned long address, unsigned long phys_addr,
  62                          unsigned long size, unsigned long flags)
  63 {
  64         pgd_t * dir;
  65         int error = 0;
  66         unsigned long end = address + size;
  67
  68         phys_addr -= address;
  69         dir = pgd_offset(&init_mm, address);
  70         flush_cache_all();
  71         if (address >= end)
  72                 BUG();
  73         spin_lock(&init_mm.page_table_lock);
  74         do {
  75                 pmd_t *pmd;
  76                 pmd = pmd_alloc(&init_mm, dir, address);
  77                 error = -ENOMEM;
  78                 if (!pmd)
  79                         break;
  80                 if (remap_area_pmd(pmd, address, end - address,
  81                                    phys_addr + address, flags))
  82                         break;
  83                 error = 0;
  84                 address = (address + PGDIR_SIZE) & PGDIR_MASK;
  85                 dir++;
  86         } while (address && (address < end));
  87         spin_unlock(&init_mm.page_table_lock);
  88         return error;
  89 }
  90