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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 static inline pte_t mk_pte_io(unsigned long page, pgprot_t prot, int space)
  19 {
  20         pte_t pte;
  21         pte_val(pte) = (((page) | pgprot_val(prot) | _PAGE_E) &
  22                         ~(unsigned long)_PAGE_CACHE);
  23         pte_val(pte) |= (((unsigned long)space) << 32);
  24         return pte;
  25 }
  26
  27 /* Remap IO memory, the same way as remap_pfn_range(), but use
  28  * the obio memory space.
  29  *
  30  * They use a pgprot that sets PAGE_IO and does not check the
  31  * mem_map table as this is independent of normal memory.
  32  */
  33 static inline void io_remap_pte_range(struct mm_struct *mm, pte_t * pte,
  34                                       unsigned long address,
  35                                       unsigned long size,
  36                                       unsigned long offset, pgprot_t prot,
  37                                       int space)
  38 {
  39         unsigned long end;
  40
  41         /* clear hack bit that was used as a write_combine side-effect flag */
  42         offset &= ~0x1UL;
  43         address &= ~PMD_MASK;
  44         end = address + size;
  45         if (end > PMD_SIZE)
  46                 end = PMD_SIZE;
  47         do {
  48                 pte_t entry;
  49                 unsigned long curend = address + PAGE_SIZE;
  50
  51                 entry = mk_pte_io(offset, prot, space);
  52                 if (!(address & 0xffff)) {
  53                         if (!(address & 0x3fffff) && !(offset & 0x3ffffe) && end >= address + 0x400000) {
  54                                 entry = mk_pte_io(offset,
  55                                                   __pgprot(pgprot_val (prot) | _PAGE_SZ4MB),
  56                                                   space);
  57                                 curend = address + 0x400000;
  58                                 offset += 0x400000;
  59                         } else if (!(address & 0x7ffff) && !(offset & 0x7fffe) && end >= address + 0x80000) {
  60                                 entry = mk_pte_io(offset,
  61                                                   __pgprot(pgprot_val (prot) | _PAGE_SZ512K),
  62                                                   space);
  63                                 curend = address + 0x80000;
  64                                 offset += 0x80000;
  65                         } else if (!(offset & 0xfffe) && end >= address + 0x10000) {
  66                                 entry = mk_pte_io(offset,
  67                                                   __pgprot(pgprot_val (prot) | _PAGE_SZ64K),
  68                                                   space);
  69                                 curend = address + 0x10000;
  70                                 offset += 0x10000;
  71                         } else
  72                                 offset += PAGE_SIZE;
  73                 } else
  74                         offset += PAGE_SIZE;
  75
  76                 do {
  77                         BUG_ON(!pte_none(*pte));
  78                         set_pte_at(mm, address, pte, entry);
  79                         address += PAGE_SIZE;
  80                         pte++;
  81                 } while (address < curend);
  82         } while (address < end);
  83 }
  84
  85 static inline int io_remap_pmd_range(struct mm_struct *mm, pmd_t * pmd, unsigned long address, unsigned long size,
  86         unsigned long offset, pgprot_t prot, int space)
  87 {
  88         unsigned long end;
  89
  90         address &= ~PGDIR_MASK;
  91         end = address + size;
  92         if (end > PGDIR_SIZE)
  93                 end = PGDIR_SIZE;
  94         offset -= address;
  95         do {
  96                 pte_t * pte = pte_alloc_map(mm, pmd, address);
  97                 if (!pte)
  98                         return -ENOMEM;
  99                 io_remap_pte_range(mm, pte, address, end - address, address + offset, prot, space);
 100                 pte_unmap(pte);
 101                 address = (address + PMD_SIZE) & PMD_MASK;
 102                 pmd++;
 103         } while (address < end);
 104         return 0;
 105 }
 106
 107 static inline int io_remap_pud_range(struct mm_struct *mm, pud_t * pud, unsigned long address, unsigned long size,
 108         unsigned long offset, pgprot_t prot, int space)
 109 {
 110         unsigned long end;
 111
 112         address &= ~PUD_MASK;
 113         end = address + size;
 114         if (end > PUD_SIZE)
 115                 end = PUD_SIZE;
 116         offset -= address;
 117         do {
 118                 pmd_t *pmd = pmd_alloc(mm, pud, address);
 119                 if (!pud)
 120                         return -ENOMEM;
 121                 io_remap_pmd_range(mm, pmd, address, end - address, address + offset, prot, space);
 122                 address = (address + PUD_SIZE) & PUD_MASK;
 123                 pud++;
 124         } while (address < end);
 125         return 0;
 126 }
 127
 128 int io_remap_pfn_range(struct vm_area_struct *vma, unsigned long from,
 129                 unsigned long pfn, unsigned long size, pgprot_t prot)
 130 {
 131         int error = 0;
 132         pgd_t * dir;
 133         unsigned long beg = from;
 134         unsigned long end = from + size;
 135         struct mm_struct *mm = vma->vm_mm;
 136         int space = GET_IOSPACE(pfn);
 137         unsigned long offset = GET_PFN(pfn) << PAGE_SHIFT;
 138         unsigned long phys_base;
 139
 140         phys_base = offset | (((unsigned long) space) << 32UL);
 141
 142         /* See comment in mm/memory.c remap_pfn_range */
 143         vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP;
 144         vma->vm_pgoff = phys_base >> PAGE_SHIFT;
 145
 146         prot = __pgprot(pg_iobits);
 147         offset -= from;
 148         dir = pgd_offset(mm, from);
 149         flush_cache_range(vma, beg, end);
 150
 151         while (from < end) {
 152                 pud_t *pud = pud_alloc(mm, dir, from);
 153                 error = -ENOMEM;
 154                 if (!pud)
 155                         break;
 156                 error = io_remap_pud_range(mm, pud, from, end - from, offset + from, prot, space);
 157                 if (error)
 158                         break;
 159                 from = (from + PGDIR_SIZE) & PGDIR_MASK;
 160                 dir++;
 161         }
 162
 163         flush_tlb_range(vma, beg, end);
 164         return error;
 165 }