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   1 /* $Id: generic.c,v 1.18 2001/12/21 04:56:15 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 #include <linux/pagemap.h>
  12
  13 #include <asm/pgalloc.h>
  14 #include <asm/pgtable.h>
  15 #include <asm/page.h>
  16 #include <asm/tlbflush.h>
  17
  18 /* Remap IO memory, the same way as remap_pfn_range(), but use
  19  * the obio memory space.
  20  *
  21  * They use a pgprot that sets PAGE_IO and does not check the
  22  * mem_map table as this is independent of normal memory.
  23  */
  24 static inline void io_remap_pte_range(struct mm_struct *mm, pte_t * pte,
  25                                       unsigned long address,
  26                                       unsigned long size,
  27                                       unsigned long offset, pgprot_t prot,
  28                                       int space)
  29 {
  30         unsigned long end;
  31
  32         /* clear hack bit that was used as a write_combine side-effect flag */
  33         offset &= ~0x1UL;
  34         address &= ~PMD_MASK;
  35         end = address + size;
  36         if (end > PMD_SIZE)
  37                 end = PMD_SIZE;
  38         do {
  39                 pte_t entry;
  40                 unsigned long curend = address + PAGE_SIZE;
  41
  42                 entry = mk_pte_io(offset, prot, space, PAGE_SIZE);
  43                 if (!(address & 0xffff)) {
  44                         if (PAGE_SIZE < (4 * 1024 * 1024) &&
  45                             !(address & 0x3fffff) &&
  46                             !(offset & 0x3ffffe) &&
  47                             end >= address + 0x400000) {
  48                                 entry = mk_pte_io(offset, prot, space,
  49                                                   4 * 1024 * 1024);
  50                                 curend = address + 0x400000;
  51                                 offset += 0x400000;
  52                         } else if (PAGE_SIZE < (512 * 1024) &&
  53                                    !(address & 0x7ffff) &&
  54                                    !(offset & 0x7fffe) &&
  55                                    end >= address + 0x80000) {
  56                                 entry = mk_pte_io(offset, prot, space,
  57                                                   512 * 1024 * 1024);
  58                                 curend = address + 0x80000;
  59                                 offset += 0x80000;
  60                         } else if (PAGE_SIZE < (64 * 1024) &&
  61                                    !(offset & 0xfffe) &&
  62                                    end >= address + 0x10000) {
  63                                 entry = mk_pte_io(offset, prot, space,
  64                                                   64 * 1024);
  65                                 curend = address + 0x10000;
  66                                 offset += 0x10000;
  67                         } else
  68                                 offset += PAGE_SIZE;
  69                 } else
  70                         offset += PAGE_SIZE;
  71
  72                 do {
  73                         BUG_ON(!pte_none(*pte));
  74                         set_pte_at(mm, address, pte, entry);
  75                         address += PAGE_SIZE;
  76                         pte_val(entry) += PAGE_SIZE;
  77                         pte++;
  78                 } while (address < curend);
  79         } while (address < end);
  80 }
  81
  82 static inline int io_remap_pmd_range(struct mm_struct *mm, pmd_t * pmd, unsigned long address, unsigned long size,
  83         unsigned long offset, pgprot_t prot, int space)
  84 {
  85         unsigned long end;
  86
  87         address &= ~PGDIR_MASK;
  88         end = address + size;
  89         if (end > PGDIR_SIZE)
  90                 end = PGDIR_SIZE;
  91         offset -= address;
  92         do {
  93                 pte_t * pte = pte_alloc_map(mm, pmd, address);
  94                 if (!pte)
  95                         return -ENOMEM;
  96                 io_remap_pte_range(mm, pte, address, end - address, address + offset, prot, space);
  97                 pte_unmap(pte);
  98                 address = (address + PMD_SIZE) & PMD_MASK;
  99                 pmd++;
 100         } while (address < end);
 101         return 0;
 102 }
 103
 104 static inline int io_remap_pud_range(struct mm_struct *mm, pud_t * pud, unsigned long address, unsigned long size,
 105         unsigned long offset, pgprot_t prot, int space)
 106 {
 107         unsigned long end;
 108
 109         address &= ~PUD_MASK;
 110         end = address + size;
 111         if (end > PUD_SIZE)
 112                 end = PUD_SIZE;
 113         offset -= address;
 114         do {
 115                 pmd_t *pmd = pmd_alloc(mm, pud, address);
 116                 if (!pud)
 117                         return -ENOMEM;
 118                 io_remap_pmd_range(mm, pmd, address, end - address, address + offset, prot, space);
 119                 address = (address + PUD_SIZE) & PUD_MASK;
 120                 pud++;
 121         } while (address < end);
 122         return 0;
 123 }
 124
 125 int io_remap_pfn_range(struct vm_area_struct *vma, unsigned long from,
 126                 unsigned long pfn, unsigned long size, pgprot_t prot)
 127 {
 128         int error = 0;
 129         pgd_t * dir;
 130         unsigned long beg = from;
 131         unsigned long end = from + size;
 132         struct mm_struct *mm = vma->vm_mm;
 133         int space = GET_IOSPACE(pfn);
 134         unsigned long offset = GET_PFN(pfn) << PAGE_SHIFT;
 135         unsigned long phys_base;
 136
 137         phys_base = offset | (((unsigned long) space) << 32UL);
 138
 139         /* See comment in mm/memory.c remap_pfn_range */
 140         vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP;
 141         vma->vm_pgoff = phys_base >> PAGE_SHIFT;
 142
 143         offset -= from;
 144         dir = pgd_offset(mm, from);
 145         flush_cache_range(vma, beg, end);
 146
 147         while (from < end) {
 148                 pud_t *pud = pud_alloc(mm, dir, from);
 149                 error = -ENOMEM;
 150                 if (!pud)
 151                         break;
 152                 error = io_remap_pud_range(mm, pud, from, end - from, offset + from, prot, space);
 153                 if (error)
 154                         break;
 155                 from = (from + PGDIR_SIZE) & PGDIR_MASK;
 156                 dir++;
 157         }
 158
 159         flush_tlb_range(vma, beg, end);
 160         return error;
 161 }