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/io.h>
  19 #include <asm/sun3mmu.h>
  20
  21 #include "../sun3/sun3.h"
  22
  23 #undef SUN3_KMAP_DEBUG
  24
  25 extern void mmu_emu_map_pmeg (int context, int vaddr);
  26
  27 static inline void do_page_mapin(unsigned long phys, unsigned long virt,
  28                                  unsigned long type)
  29 {
  30         unsigned long pte;
  31         pte_t ptep;
  32
  33         ptep = pfn_pte(phys >> PAGE_SHIFT, PAGE_KERNEL);
  34         pte = pte_val(ptep);
  35         pte |= type;
  36
  37         sun3_put_pte(virt, pte);
  38
  39 #ifdef SUN3_KMAP_DEBUG
  40         pr_info("mapin:");
  41         print_pte_vaddr(virt);
  42 #endif
  43
  44 }
  45
  46 static inline void do_pmeg_mapin(unsigned long phys, unsigned long virt,
  47                                  unsigned long type, int pages)
  48 {
  49
  50         if(sun3_get_segmap(virt & ~SUN3_PMEG_MASK) == SUN3_INVALID_PMEG)
  51                 mmu_emu_map_pmeg(sun3_get_context(), virt);
  52
  53         while(pages) {
  54                 do_page_mapin(phys, virt, type);
  55                 phys += PAGE_SIZE;
  56                 virt += PAGE_SIZE;
  57                 pages--;
  58         }
  59 }
  60
  61 void __iomem *sun3_ioremap(unsigned long phys, unsigned long size,
  62                    unsigned long type)
  63 {
  64         struct vm_struct *area;
  65         unsigned long offset, virt, ret;
  66         int pages;
  67
  68         if(!size)
  69                 return NULL;
  70
  71         /* page align */
  72         offset = phys & (PAGE_SIZE-1);
  73         phys &= ~(PAGE_SIZE-1);
  74
  75         size += offset;
  76         size = PAGE_ALIGN(size);
  77         if((area = get_vm_area(size, VM_IOREMAP)) == NULL)
  78                 return NULL;
  79
  80 #ifdef SUN3_KMAP_DEBUG
  81         pr_info("ioremap: got virt %p size %lx(%lx)\n", area->addr, size,
  82                 area->size);
  83 #endif
  84
  85         pages = size / PAGE_SIZE;
  86         virt = (unsigned long)area->addr;
  87         ret = virt + offset;
  88
  89         while(pages) {
  90                 int seg_pages;
  91
  92                 seg_pages = (SUN3_PMEG_SIZE - (virt & SUN3_PMEG_MASK)) / PAGE_SIZE;
  93                 if(seg_pages > pages)
  94                         seg_pages = pages;
  95
  96                 do_pmeg_mapin(phys, virt, type, seg_pages);
  97
  98                 pages -= seg_pages;
  99                 phys += seg_pages * PAGE_SIZE;
 100                 virt += seg_pages * PAGE_SIZE;
 101         }
 102
 103         return (void __iomem *)ret;
 104
 105 }
 106 EXPORT_SYMBOL(sun3_ioremap);
 107
 108
 109 void __iomem *__ioremap(unsigned long phys, unsigned long size, int cache)
 110 {
 111
 112         return sun3_ioremap(phys, size, SUN3_PAGE_TYPE_IO);
 113
 114 }
 115 EXPORT_SYMBOL(__ioremap);
 116
 117 void iounmap(void __iomem *addr)
 118 {
 119         vfree((void *)(PAGE_MASK & (unsigned long)addr));
 120 }
 121 EXPORT_SYMBOL(iounmap);
 122
 123 /* sun3_map_test(addr, val) -- Reads a byte from addr, storing to val,
 124  * trapping the potential read fault.  Returns 0 if the access faulted,
 125  * 1 on success.
 126  *
 127  * This function is primarily used to check addresses on the VME bus.
 128  *
 129  * Mucking with the page fault handler seems a little hackish to me, but
 130  * SunOS, NetBSD, and Mach all implemented this check in such a manner,
 131  * so I figure we're allowed.
 132  */
 133 int sun3_map_test(unsigned long addr, char *val)
 134 {
 135         int ret = 0;
 136
 137         __asm__ __volatile__
 138                 (".globl _sun3_map_test_start\n"
 139                  "_sun3_map_test_start:\n"
 140                  "1: moveb (%2), (%0)\n"
 141                  "   moveq #1, %1\n"
 142                  "2:\n"
 143                  ".section .fixup,\"ax\"\n"
 144                  ".even\n"
 145                  "3: moveq #0, %1\n"
 146                  "   jmp 2b\n"
 147                  ".previous\n"
 148                  ".section __ex_table,\"a\"\n"
 149                  ".align 4\n"
 150                  ".long 1b,3b\n"
 151                  ".previous\n"
 152                  ".globl _sun3_map_test_end\n"
 153                  "_sun3_map_test_end:\n"
 154                  : "=a"(val), "=r"(ret)
 155                  : "a"(addr));
 156
 157         return ret;
 158 }
 159 EXPORT_SYMBOL(sun3_map_test);