arch/alpha/mm/remap.c

   1 #include <linux/vmalloc.h>
   2 #include <asm/pgalloc.h>
   3
   4 /* called with the page_table_lock held */
   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
  11         address &= ~PMD_MASK;
  12         end = address + size;
  13         if (end > PMD_SIZE)
  14                 end = PMD_SIZE;
  15         if (address >= end)
  16                 BUG();
  17         do {
  18                 if (!pte_none(*pte)) {
  19                         printk("remap_area_pte: page already exists\n");
  20                         BUG();
  21                 }
  22                 set_pte(pte,
  23                         mk_pte_phys(phys_addr,
  24                                     __pgprot(_PAGE_VALID | _PAGE_ASM |
  25                                              _PAGE_KRE | _PAGE_KWE | flags)));
  26                 address += PAGE_SIZE;
  27                 phys_addr += PAGE_SIZE;
  28                 pte++;
  29         } while (address && (address < end));
  30 }
  31
  32 /* called with the page_table_lock held */
  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(&init_mm, 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         spin_lock(&init_mm.page_table_lock);
  72         do {
  73                 pmd_t *pmd;
  74                 pmd = pmd_alloc(&init_mm, dir, address);
  75                 error = -ENOMEM;
  76                 if (!pmd)
  77                         break;
  78                 if (remap_area_pmd(pmd, address, end - address,
  79                                    phys_addr + address, flags))
  80                         break;
  81                 error = 0;
  82                 address = (address + PGDIR_SIZE) & PGDIR_MASK;
  83                 dir++;
  84         } while (address && (address < end));
  85         spin_unlock(&init_mm.page_table_lock);
  86         return error;
  87 }
  88