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
  25 extern void print_pte_vaddr(unsigned long vaddr);
  26 #endif
  27
  28 extern void mmu_emu_map_pmeg (int context, int vaddr);
  29
  30 static 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
  48 static 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
  63 void __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 }
 108 EXPORT_SYMBOL(sun3_ioremap);
 109
 110
 111 void __iomem *__ioremap(unsigned long phys, unsigned long size, int cache)
 112 {
 113
 114         return sun3_ioremap(phys, size, SUN3_PAGE_TYPE_IO);
 115
 116 }
 117 EXPORT_SYMBOL(__ioremap);
 118
 119 void iounmap(void __iomem *addr)
 120 {
 121         vfree((void *)(PAGE_MASK & (unsigned long)addr));
 122 }
 123 EXPORT_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  */
 135 int 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 }
 161 EXPORT_SYMBOL(sun3_map_test);