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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);
  43                 if (!(address & 0xffff)) {
  44                         if (!(address & 0x3fffff) && !(offset & 0x3ffffe) && end >= address + 0x400000) {
  45                                 entry = mk_pte_io(offset,
  46                                                   __pgprot(pgprot_val (prot) | _PAGE_SZ4MB),
  47                                                   space);
  48                                 curend = address + 0x400000;
  49                                 offset += 0x400000;
  50                         } else if (!(address & 0x7ffff) && !(offset & 0x7fffe) && end >= address + 0x80000) {
  51                                 entry = mk_pte_io(offset,
  52                                                   __pgprot(pgprot_val (prot) | _PAGE_SZ512K),
  53                                                   space);
  54                                 curend = address + 0x80000;
  55                                 offset += 0x80000;
  56                         } else if (!(offset & 0xfffe) && end >= address + 0x10000) {
  57                                 entry = mk_pte_io(offset,
  58                                                   __pgprot(pgprot_val (prot) | _PAGE_SZ64K),
  59                                                   space);
  60                                 curend = address + 0x10000;
  61                                 offset += 0x10000;
  62                         } else
  63                                 offset += PAGE_SIZE;
  64                 } else
  65                         offset += PAGE_SIZE;
  66
  67                 do {
  68                         BUG_ON(!pte_none(*pte));
  69                         set_pte_at(mm, address, pte, entry);
  70                         address += PAGE_SIZE;
  71                         pte++;
  72                 } while (address < curend);
  73         } while (address < end);
  74 }
  75
  76 static inline int io_remap_pmd_range(struct mm_struct *mm, pmd_t * pmd, unsigned long address, unsigned long size,
  77         unsigned long offset, pgprot_t prot, int space)
  78 {
  79         unsigned long end;
  80
  81         address &= ~PGDIR_MASK;
  82         end = address + size;
  83         if (end > PGDIR_SIZE)
  84                 end = PGDIR_SIZE;
  85         offset -= address;
  86         do {
  87                 pte_t * pte = pte_alloc_map(mm, pmd, address);
  88                 if (!pte)
  89                         return -ENOMEM;
  90                 io_remap_pte_range(mm, pte, address, end - address, address + offset, prot, space);
  91                 pte_unmap(pte);
  92                 address = (address + PMD_SIZE) & PMD_MASK;
  93                 pmd++;
  94         } while (address < end);
  95         return 0;
  96 }
  97
  98 static inline int io_remap_pud_range(struct mm_struct *mm, pud_t * pud, unsigned long address, unsigned long size,
  99         unsigned long offset, pgprot_t prot, int space)
 100 {
 101         unsigned long end;
 102
 103         address &= ~PUD_MASK;
 104         end = address + size;
 105         if (end > PUD_SIZE)
 106                 end = PUD_SIZE;
 107         offset -= address;
 108         do {
 109                 pmd_t *pmd = pmd_alloc(mm, pud, address);
 110                 if (!pud)
 111                         return -ENOMEM;
 112                 io_remap_pmd_range(mm, pmd, address, end - address, address + offset, prot, space);
 113                 address = (address + PUD_SIZE) & PUD_MASK;
 114                 pud++;
 115         } while (address < end);
 116         return 0;
 117 }
 118
 119 int io_remap_pfn_range(struct vm_area_struct *vma, unsigned long from,
 120                 unsigned long pfn, unsigned long size, pgprot_t prot)
 121 {
 122         int error = 0;
 123         pgd_t * dir;
 124         unsigned long beg = from;
 125         unsigned long end = from + size;
 126         struct mm_struct *mm = vma->vm_mm;
 127         int space = GET_IOSPACE(pfn);
 128         unsigned long offset = GET_PFN(pfn) << PAGE_SHIFT;
 129
 130         /* See comment in mm/memory.c remap_pfn_range */
 131         vma->vm_flags |= VM_IO | VM_RESERVED;
 132
 133         prot = __pgprot(pg_iobits);
 134         offset -= from;
 135         dir = pgd_offset(mm, from);
 136         flush_cache_range(vma, beg, end);
 137
 138         while (from < end) {
 139                 pud_t *pud = pud_alloc(mm, dir, from);
 140                 error = -ENOMEM;
 141                 if (!pud)
 142                         break;
 143                 error = io_remap_pud_range(mm, pud, from, end - from, offset + from, prot, space);
 144                 if (error)
 145                         break;
 146                 from = (from + PGDIR_SIZE) & PGDIR_MASK;
 147                 dir++;
 148         }
 149
 150         flush_tlb_range(vma, beg, end);
 151         return error;
 152 }