LXR linux-old/arch/sparc64/mm/generic.c

   1/* $Id: generic.c,v 1.17 2001/04/09 04:08:06 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
  17static inline void forget_pte(pte_t page)
  18{
  19        if (pte_none(page))
  20                return;
  21        if (pte_present(page)) {
  22                struct page *ptpage = pte_page(page);
  23                if ((!VALID_PAGE(ptpage)) || PageReserved(ptpage))
  24                        return;
  25                page_cache_release(ptpage);
  26                return;
  27        }
  28        swap_free(pte_to_swp_entry(page));
  29}
  30
  31/* Remap IO memory, the same way as remap_page_range(), but use
  32 * the obio memory space.
  33 *
  34 * They use a pgprot that sets PAGE_IO and does not check the
  35 * mem_map table as this is independent of normal memory.
  36 *
  37 * As a special hack if the lowest bit of offset is set the
  38 * side-effect bit will be turned off.  This is used as a
  39 * performance improvement on FFB/AFB. -DaveM
  40 */
  41static inline void io_remap_pte_range(pte_t * pte, unsigned long address, unsigned long size,
  42        unsigned long offset, pgprot_t prot, int space)
  43{
  44        unsigned long end;
  45
  46        address &= ~PMD_MASK;
  47        end = address + size;
  48        if (end > PMD_SIZE)
  49                end = PMD_SIZE;
  50        do {
  51                pte_t oldpage;
  52                pte_t entry;
  53                unsigned long curend = address + PAGE_SIZE;
  54                
  55                entry = mk_pte_io((offset & ~(0x1UL)), prot, space);
  56                if (!(address & 0xffff)) {
  57                        if (!(address & 0x3fffff) && !(offset & 0x3ffffe) && end >= address + 0x400000) {
  58                                entry = mk_pte_io((offset & ~(0x1UL)),
  59                                                  __pgprot(pgprot_val (prot) | _PAGE_SZ4MB),
  60                                                  space);
  61                                curend = address + 0x400000;
  62                                offset += 0x400000;
  63                        } else if (!(address & 0x7ffff) && !(offset & 0x7fffe) && end >= address + 0x80000) {
  64                                entry = mk_pte_io((offset & ~(0x1UL)),
  65                                                  __pgprot(pgprot_val (prot) | _PAGE_SZ512K),
  66                                                  space);
  67                                curend = address + 0x80000;
  68                                offset += 0x80000;
  69                        } else if (!(offset & 0xfffe) && end >= address + 0x10000) {
  70                                entry = mk_pte_io((offset & ~(0x1UL)),
  71                                                  __pgprot(pgprot_val (prot) | _PAGE_SZ64K),
  72                                                  space);
  73                                curend = address + 0x10000;
  74                                offset += 0x10000;
  75                        } else
  76                                offset += PAGE_SIZE;
  77                } else
  78                        offset += PAGE_SIZE;
  79
  80                if (offset & 0x1UL)
  81                        pte_val(entry) &= ~(_PAGE_E);
  82                do {
  83                        oldpage = *pte;
  84                        pte_clear(pte);
  85                        set_pte(pte, entry);
  86                        forget_pte(oldpage);
  87                        address += PAGE_SIZE;
  88                        pte++;
  89                } while (address < curend);
  90        } while (address < end);
  91}
  92
  93static inline int io_remap_pmd_range(pmd_t * pmd, unsigned long address, unsigned long size,
  94        unsigned long offset, pgprot_t prot, int space)
  95{
  96        unsigned long end;
  97
  98        address &= ~PGDIR_MASK;
  99        end = address + size;
 100        if (end > PGDIR_SIZE)
 101                end = PGDIR_SIZE;
 102        offset -= address;
 103        do {
 104                pte_t * pte = pte_alloc(current->mm, pmd, address);
 105                if (!pte)
 106                        return -ENOMEM;
 107                io_remap_pte_range(pte, address, end - address, address + offset, prot, space);
 108                address = (address + PMD_SIZE) & PMD_MASK;
 109                pmd++;
 110        } while (address < end);
 111        return 0;
 112}
 113
 114int io_remap_page_range(unsigned long from, unsigned long offset, unsigned long size, pgprot_t prot, int space)
 115{
 116        int error = 0;
 117        pgd_t * dir;
 118        unsigned long beg = from;
 119        unsigned long end = from + size;
 120        struct mm_struct *mm = current->mm;
 121
 122        prot = __pgprot(pg_iobits);
 123        offset -= from;
 124        dir = pgd_offset(mm, from);
 125        flush_cache_range(mm, beg, end);
 126
 127        spin_lock(&mm->page_table_lock);
 128        while (from < end) {
 129                pmd_t *pmd = pmd_alloc(current->mm, dir, from);
 130                error = -ENOMEM;
 131                if (!pmd)
 132                        break;
 133                error = io_remap_pmd_range(pmd, from, end - from, offset + from, prot, space);
 134                if (error)
 135                        break;
 136                from = (from + PGDIR_SIZE) & PGDIR_MASK;
 137                dir++;
 138        }
 139        spin_unlock(&mm->page_table_lock);
 140
 141        flush_tlb_range(current->mm, beg, end);
 142        return error;
 143}
 144