arch/sparc64/mm/generic.c

   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  * As a special hack if the lowest bit of offset is set the
  25  * side-effect bit will be turned off.  This is used as a
  26  * performance improvement on FFB/AFB. -DaveM
  27  */
  28 static inline void io_remap_pte_range(pte_t * pte, unsigned long address, unsigned long size,
  29         unsigned long offset, pgprot_t prot, int space)
  30 {
  31         unsigned long end;
  32
  33         address &= ~PMD_MASK;
  34         end = address + size;
  35         if (end > PMD_SIZE)
  36                 end = PMD_SIZE;
  37         do {
  38                 pte_t entry;
  39                 unsigned long curend = address + PAGE_SIZE;
  40
  41                 entry = mk_pte_io((offset & ~(0x1UL)), prot, space);
  42                 if (!(address & 0xffff)) {
  43                         if (!(address & 0x3fffff) && !(offset & 0x3ffffe) && end >= address + 0x400000) {
  44                                 entry = mk_pte_io((offset & ~(0x1UL)),
  45                                                   __pgprot(pgprot_val (prot) | _PAGE_SZ4MB),
  46                                                   space);
  47                                 curend = address + 0x400000;
  48                                 offset += 0x400000;
  49                         } else if (!(address & 0x7ffff) && !(offset & 0x7fffe) && end >= address + 0x80000) {
  50                                 entry = mk_pte_io((offset & ~(0x1UL)),
  51                                                   __pgprot(pgprot_val (prot) | _PAGE_SZ512K),
  52                                                   space);
  53                                 curend = address + 0x80000;
  54                                 offset += 0x80000;
  55                         } else if (!(offset & 0xfffe) && end >= address + 0x10000) {
  56                                 entry = mk_pte_io((offset & ~(0x1UL)),
  57                                                   __pgprot(pgprot_val (prot) | _PAGE_SZ64K),
  58                                                   space);
  59                                 curend = address + 0x10000;
  60                                 offset += 0x10000;
  61                         } else
  62                                 offset += PAGE_SIZE;
  63                 } else
  64                         offset += PAGE_SIZE;
  65
  66                 if (offset & 0x1UL)
  67                         pte_val(entry) &= ~(_PAGE_E);
  68                 do {
  69                         BUG_ON(!pte_none(*pte));
  70                         set_pte(pte, entry);
  71                         address += PAGE_SIZE;
  72                         pte++;
  73                 } while (address < curend);
  74         } while (address < end);
  75 }
  76
  77 static inline int io_remap_pmd_range(pmd_t * pmd, unsigned long address, unsigned long size,
  78         unsigned long offset, pgprot_t prot, int space)
  79 {
  80         unsigned long end;
  81
  82         address &= ~PGDIR_MASK;
  83         end = address + size;
  84         if (end > PGDIR_SIZE)
  85                 end = PGDIR_SIZE;
  86         offset -= address;
  87         do {
  88                 pte_t * pte = pte_alloc_map(current->mm, pmd, address);
  89                 if (!pte)
  90                         return -ENOMEM;
  91                 io_remap_pte_range(pte, address, end - address, address + offset, prot, space);
  92                 pte_unmap(pte);
  93                 address = (address + PMD_SIZE) & PMD_MASK;
  94                 pmd++;
  95         } while (address < end);
  96         return 0;
  97 }
  98
  99 static inline int io_remap_pud_range(pud_t * pud, unsigned long address, unsigned long size,
 100         unsigned long offset, pgprot_t prot, int space)
 101 {
 102         unsigned long end;
 103
 104         address &= ~PUD_MASK;
 105         end = address + size;
 106         if (end > PUD_SIZE)
 107                 end = PUD_SIZE;
 108         offset -= address;
 109         do {
 110                 pmd_t *pmd = pmd_alloc(current->mm, pud, address);
 111                 if (!pud)
 112                         return -ENOMEM;
 113                 io_remap_pmd_range(pmd, address, end - address, address + offset, prot, space);
 114                 address = (address + PUD_SIZE) & PUD_MASK;
 115                 pud++;
 116         } while (address < end);
 117         return 0;
 118 }
 119
 120 int io_remap_page_range(struct vm_area_struct *vma, unsigned long from, unsigned long offset, unsigned long size, pgprot_t prot, int space)
 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
 128         prot = __pgprot(pg_iobits);
 129         offset -= from;
 130         dir = pgd_offset(mm, from);
 131         flush_cache_range(vma, beg, end);
 132
 133         spin_lock(&mm->page_table_lock);
 134         while (from < end) {
 135                 pud_t *pud = pud_alloc(current->mm, dir, from);
 136                 error = -ENOMEM;
 137                 if (!pud)
 138                         break;
 139                 error = io_remap_pud_range(pud, from, end - from, offset + from, prot, space);
 140                 if (error)
 141                         break;
 142                 from = (from + PGDIR_SIZE) & PGDIR_MASK;
 143                 dir++;
 144         }
 145         flush_tlb_range(vma, beg, end);
 146         spin_unlock(&mm->page_table_lock);
 147
 148         return error;
 149 }