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