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         pr_info("mapin:");
  44         print_pte_vaddr(virt);
  45 #endif
  46
  47 }
  48
  49 static inline void do_pmeg_mapin(unsigned long phys, unsigned long virt,
  50                                  unsigned long type, int pages)
  51 {
  52
  53         if(sun3_get_segmap(virt & ~SUN3_PMEG_MASK) == SUN3_INVALID_PMEG)
  54                 mmu_emu_map_pmeg(sun3_get_context(), virt);
  55
  56         while(pages) {
  57                 do_page_mapin(phys, virt, type);
  58                 phys += PAGE_SIZE;
  59                 virt += PAGE_SIZE;
  60                 pages--;
  61         }
  62 }
  63
  64 void __iomem *sun3_ioremap(unsigned long phys, unsigned long size,
  65                    unsigned long type)
  66 {
  67         struct vm_struct *area;
  68         unsigned long offset, virt, ret;
  69         int pages;
  70
  71         if(!size)
  72                 return NULL;
  73
  74         /* page align */
  75         offset = phys & (PAGE_SIZE-1);
  76         phys &= ~(PAGE_SIZE-1);
  77
  78         size += offset;
  79         size = PAGE_ALIGN(size);
  80         if((area = get_vm_area(size, VM_IOREMAP)) == NULL)
  81                 return NULL;
  82
  83 #ifdef SUN3_KMAP_DEBUG
  84         pr_info("ioremap: got virt %p size %lx(%lx)\n", area->addr, size,
  85                 area->size);
  86 #endif
  87
  88         pages = size / PAGE_SIZE;
  89         virt = (unsigned long)area->addr;
  90         ret = virt + offset;
  91
  92         while(pages) {
  93                 int seg_pages;
  94
  95                 seg_pages = (SUN3_PMEG_SIZE - (virt & SUN3_PMEG_MASK)) / PAGE_SIZE;
  96                 if(seg_pages > pages)
  97                         seg_pages = pages;
  98
  99                 do_pmeg_mapin(phys, virt, type, seg_pages);
 100
 101                 pages -= seg_pages;
 102                 phys += seg_pages * PAGE_SIZE;
 103                 virt += seg_pages * PAGE_SIZE;
 104         }
 105
 106         return (void __iomem *)ret;
 107
 108 }
 109 EXPORT_SYMBOL(sun3_ioremap);
 110
 111
 112 void __iomem *__ioremap(unsigned long phys, unsigned long size, int cache)
 113 {
 114
 115         return sun3_ioremap(phys, size, SUN3_PAGE_TYPE_IO);
 116
 117 }
 118 EXPORT_SYMBOL(__ioremap);
 119
 120 void iounmap(void __iomem *addr)
 121 {
 122         vfree((void *)(PAGE_MASK & (unsigned long)addr));
 123 }
 124 EXPORT_SYMBOL(iounmap);
 125
 126 /* sun3_map_test(addr, val) -- Reads a byte from addr, storing to val,
 127  * trapping the potential read fault.  Returns 0 if the access faulted,
 128  * 1 on success.
 129  *
 130  * This function is primarily used to check addresses on the VME bus.
 131  *
 132  * Mucking with the page fault handler seems a little hackish to me, but
 133  * SunOS, NetBSD, and Mach all implemented this check in such a manner,
 134  * so I figure we're allowed.
 135  */
 136 int sun3_map_test(unsigned long addr, char *val)
 137 {
 138         int ret = 0;
 139
 140         __asm__ __volatile__
 141                 (".globl _sun3_map_test_start\n"
 142                  "_sun3_map_test_start:\n"
 143                  "1: moveb (%2), (%0)\n"
 144                  "   moveq #1, %1\n"
 145                  "2:\n"
 146                  ".section .fixup,\"ax\"\n"
 147                  ".even\n"
 148                  "3: moveq #0, %1\n"
 149                  "   jmp 2b\n"
 150                  ".previous\n"
 151                  ".section __ex_table,\"a\"\n"
 152                  ".align 4\n"
 153                  ".long 1b,3b\n"
 154                  ".previous\n"
 155                  ".globl _sun3_map_test_end\n"
 156                  "_sun3_map_test_end:\n"
 157                  : "=a"(val), "=r"(ret)
 158                  : "a"(addr));
 159
 160         return ret;
 161 }
 162 EXPORT_SYMBOL(sun3_map_test);