LXR linux/arch/m68k/mm/sun3kmap.c

   1/*
   2 * linux/arch/m68k/mm/sun3kmap.c
   3 *
   4 * Copyright (C) 2002 Sam Creasey <sammy@sammy.net>
   5 *
   6 * This file is subject to the terms and conditions of the GNU General Public
   7 * License.  See the file COPYING in the main directory of this archive
   8 * for more details.
   9 */
  10
  11#include <linux/module.h>
  12#include <linux/types.h>
  13#include <linux/kernel.h>
  14#include <linux/mm.h>
  15#include <linux/vmalloc.h>
  16
  17#include <asm/page.h>
  18#include <asm/pgtable.h>
  19#include <asm/io.h>
  20#include <asm/sun3mmu.h>
  21
  22#undef SUN3_KMAP_DEBUG
  23
  24#ifdef SUN3_KMAP_DEBUG
  25extern void print_pte_vaddr(unsigned long vaddr);
  26#endif
  27
  28extern void mmu_emu_map_pmeg (int context, int vaddr);
  29
  30static inline void do_page_mapin(unsigned long phys, unsigned long virt,
  31                                 unsigned long type)
  32{
  33        unsigned long pte;
  34        pte_t ptep;
  35
  36        ptep = pfn_pte(phys >> PAGE_SHIFT, PAGE_KERNEL);
  37        pte = pte_val(ptep);
  38        pte |= type;
  39
  40        sun3_put_pte(virt, pte);
  41
  42#ifdef SUN3_KMAP_DEBUG
  43        print_pte_vaddr(virt);
  44#endif
  45
  46}
  47
  48static inline void do_pmeg_mapin(unsigned long phys, unsigned long virt,
  49                                 unsigned long type, int pages)
  50{
  51
  52        if(sun3_get_segmap(virt & ~SUN3_PMEG_MASK) == SUN3_INVALID_PMEG)
  53                mmu_emu_map_pmeg(sun3_get_context(), virt);
  54
  55        while(pages) {
  56                do_page_mapin(phys, virt, type);
  57                phys += PAGE_SIZE;
  58                virt += PAGE_SIZE;
  59                pages--;
  60        }
  61}
  62
  63void __iomem *sun3_ioremap(unsigned long phys, unsigned long size,
  64                   unsigned long type)
  65{
  66        struct vm_struct *area;
  67        unsigned long offset, virt, ret;
  68        int pages;
  69
  70        if(!size)
  71                return NULL;
  72
  73        /* page align */
  74        offset = phys & (PAGE_SIZE-1);
  75        phys &= ~(PAGE_SIZE-1);
  76
  77        size += offset;
  78        size = PAGE_ALIGN(size);
  79        if((area = get_vm_area(size, VM_IOREMAP)) == NULL)
  80                return NULL;
  81
  82#ifdef SUN3_KMAP_DEBUG
  83        printk("ioremap: got virt %p size %lx(%lx)\n",
  84               area->addr, size, area->size);
  85#endif
  86
  87        pages = size / PAGE_SIZE;
  88        virt = (unsigned long)area->addr;
  89        ret = virt + offset;
  90
  91        while(pages) {
  92                int seg_pages;
  93
  94                seg_pages = (SUN3_PMEG_SIZE - (virt & SUN3_PMEG_MASK)) / PAGE_SIZE;
  95                if(seg_pages > pages)
  96                        seg_pages = pages;
  97
  98                do_pmeg_mapin(phys, virt, type, seg_pages);
  99
 100                pages -= seg_pages;
 101                phys += seg_pages * PAGE_SIZE;
 102                virt += seg_pages * PAGE_SIZE;
 103        }
 104
 105        return (void __iomem *)ret;
 106
 107}
 108EXPORT_SYMBOL(sun3_ioremap);
 109
 110
 111void __iomem *__ioremap(unsigned long phys, unsigned long size, int cache)
 112{
 113
 114        return sun3_ioremap(phys, size, SUN3_PAGE_TYPE_IO);
 115
 116}
 117EXPORT_SYMBOL(__ioremap);
 118
 119void iounmap(void __iomem *addr)
 120{
 121        vfree((void *)(PAGE_MASK & (unsigned long)addr));
 122}
 123EXPORT_SYMBOL(iounmap);
 124
 125/* sun3_map_test(addr, val) -- Reads a byte from addr, storing to val,
 126 * trapping the potential read fault.  Returns 0 if the access faulted,
 127 * 1 on success.
 128 *
 129 * This function is primarily used to check addresses on the VME bus.
 130 *
 131 * Mucking with the page fault handler seems a little hackish to me, but
 132 * SunOS, NetBSD, and Mach all implemented this check in such a manner,
 133 * so I figure we're allowed.
 134 */
 135int sun3_map_test(unsigned long addr, char *val)
 136{
 137        int ret = 0;
 138
 139        __asm__ __volatile__
 140                (".globl _sun3_map_test_start\n"
 141                 "_sun3_map_test_start:\n"
 142                 "1: moveb (%2), (%0)\n"
 143                 "   moveq #1, %1\n"
 144                 "2:\n"
 145                 ".section .fixup,\"ax\"\n"
 146                 ".even\n"
 147                 "3: moveq #0, %1\n"
 148                 "   jmp 2b\n"
 149                 ".previous\n"
 150                 ".section __ex_table,\"a\"\n"
 151                 ".align 4\n"
 152                 ".long 1b,3b\n"
 153                 ".previous\n"
 154                 ".globl _sun3_map_test_end\n"
 155                 "_sun3_map_test_end:\n"
 156                 : "=a"(val), "=r"(ret)
 157                 : "a"(addr));
 158
 159        return ret;
 160}
 161EXPORT_SYMBOL(sun3_map_test);
 162