arch/alpha/mm/remap.c

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