root/arch/sparc/mm/generic.c

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DEFINITIONS

This source file includes following definitions.
  1. forget_pte
  2. io_remap_pte_range
  3. io_remap_pmd_range
  4. io_remap_page_range

   1 /* $Id: generic.c,v 1.2 1996/04/25 06:09:30 davem Exp $
   2  * generic.c: Generic Sparc mm routines that are not dependent upon
   3  *            MMU type but are Sparc specific.
   4  *
   5  * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
   6  */
   7 
   8 #include <linux/kernel.h>
   9 #include <linux/mm.h>
  10 #include <linux/swap.h>
  11 
  12 #include <asm/pgtable.h>
  13 #include <asm/page.h>
  14 
  15 static inline void forget_pte(pte_t page)
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  16 {
  17         if (pte_none(page))
  18                 return;
  19         if (pte_present(page)) {
  20                 unsigned long addr = pte_page(page);
  21                 if (addr >= high_memory || PageReserved(mem_map+MAP_NR(addr)))
  22                         return;
  23                 free_page(addr);
  24                 if (current->mm->rss <= 0)
  25                         return;
  26                 current->mm->rss--;
  27                 return;
  28         }
  29         swap_free(pte_val(page));
  30 }
  31 
  32 /* Remap IO memory, the same way as remap_page_range(), but use
  33  * the obio memory space.
  34  *
  35  * They use a pgprot that sets PAGE_IO and does not check the
  36  * mem_map table as this is independent of normal memory.
  37  */
  38 static inline void io_remap_pte_range(pte_t * pte, unsigned long address, unsigned long size,
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  39         unsigned long offset, pgprot_t prot, int space)
  40 {
  41         unsigned long end;
  42 
  43         address &= ~PMD_MASK;
  44         end = address + size;
  45         if (end > PMD_SIZE)
  46                 end = PMD_SIZE;
  47         do {
  48                 pte_t oldpage = *pte;
  49                 pte_clear(pte);
  50                 set_pte(pte, mk_pte_io(offset, prot, space));
  51                 forget_pte(oldpage);
  52                 address += PAGE_SIZE;
  53                 offset += PAGE_SIZE;
  54                 pte++;
  55         } while (address < end);
  56 }
  57 
  58 static inline int io_remap_pmd_range(pmd_t * pmd, unsigned long address, unsigned long size,
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  59         unsigned long offset, pgprot_t prot, int space)
  60 {
  61         unsigned long end;
  62 
  63         address &= ~PGDIR_MASK;
  64         end = address + size;
  65         if (end > PGDIR_SIZE)
  66                 end = PGDIR_SIZE;
  67         offset -= address;
  68         do {
  69                 pte_t * pte = pte_alloc(pmd, address);
  70                 if (!pte)
  71                         return -ENOMEM;
  72                 io_remap_pte_range(pte, address, end - address, address + offset, prot, space);
  73                 address = (address + PMD_SIZE) & PMD_MASK;
  74                 pmd++;
  75         } while (address < end);
  76         return 0;
  77 }
  78 
  79 int io_remap_page_range(unsigned long from, unsigned long offset, unsigned long size, pgprot_t prot, int space)
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  80 {
  81         int error = 0;
  82         pgd_t * dir;
  83         unsigned long beg = from;
  84         unsigned long end = from + size;
  85 
  86         pgprot_val(prot) = pg_iobits;
  87         offset -= from;
  88         dir = pgd_offset(current->mm, from);
  89         flush_cache_range(current->mm, beg, end);
  90         while (from < end) {
  91                 pmd_t *pmd = pmd_alloc(dir, from);
  92                 error = -ENOMEM;
  93                 if (!pmd)
  94                         break;
  95                 error = io_remap_pmd_range(pmd, from, end - from, offset + from, prot, space);
  96                 if (error)
  97                         break;
  98                 from = (from + PGDIR_SIZE) & PGDIR_MASK;
  99                 dir++;
 100         }
 101         flush_tlb_range(current->mm, beg, end);
 102         return error;
 103 }

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