arch/x86/kernel/probe_roms_32.c

   1 #include <linux/sched.h>
   2 #include <linux/mm.h>
   3 #include <linux/uaccess.h>
   4 #include <linux/mmzone.h>
   5 #include <linux/ioport.h>
   6 #include <linux/seq_file.h>
   7 #include <linux/console.h>
   8 #include <linux/init.h>
   9 #include <linux/edd.h>
  10 #include <linux/dmi.h>
  11 #include <linux/pfn.h>
  12 #include <linux/pci.h>
  13 #include <asm/pci-direct.h>
  14
  15
  16 #include <asm/e820.h>
  17 #include <asm/mmzone.h>
  18 #include <asm/setup.h>
  19 #include <asm/sections.h>
  20 #include <asm/io.h>
  21 #include <asm/setup_arch.h>
  22
  23 static struct resource system_rom_resource = {
  24         .name   = "System ROM",
  25         .start  = 0xf0000,
  26         .end    = 0xfffff,
  27         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  28 };
  29
  30 static struct resource extension_rom_resource = {
  31         .name   = "Extension ROM",
  32         .start  = 0xe0000,
  33         .end    = 0xeffff,
  34         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  35 };
  36
  37 static struct resource adapter_rom_resources[] = { {
  38         .name   = "Adapter ROM",
  39         .start  = 0xc8000,
  40         .end    = 0,
  41         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  42 }, {
  43         .name   = "Adapter ROM",
  44         .start  = 0,
  45         .end    = 0,
  46         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  47 }, {
  48         .name   = "Adapter ROM",
  49         .start  = 0,
  50         .end    = 0,
  51         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  52 }, {
  53         .name   = "Adapter ROM",
  54         .start  = 0,
  55         .end    = 0,
  56         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  57 }, {
  58         .name   = "Adapter ROM",
  59         .start  = 0,
  60         .end    = 0,
  61         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  62 }, {
  63         .name   = "Adapter ROM",
  64         .start  = 0,
  65         .end    = 0,
  66         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  67 } };
  68
  69 static struct resource video_rom_resource = {
  70         .name   = "Video ROM",
  71         .start  = 0xc0000,
  72         .end    = 0xc7fff,
  73         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  74 };
  75
  76 #define ROMSIGNATURE 0xaa55
  77
  78 static int __init romsignature(const unsigned char *rom)
  79 {
  80         const unsigned short * const ptr = (const unsigned short *)rom;
  81         unsigned short sig;
  82
  83         return probe_kernel_address(ptr, sig) == 0 && sig == ROMSIGNATURE;
  84 }
  85
  86 static int __init romchecksum(const unsigned char *rom, unsigned long length)
  87 {
  88         unsigned char sum, c;
  89
  90         for (sum = 0; length && probe_kernel_address(rom++, c) == 0; length--)
  91                 sum += c;
  92         return !length && !sum;
  93 }
  94
  95 void __init probe_roms(void)
  96 {
  97         const unsigned char *rom;
  98         unsigned long start, length, upper;
  99         unsigned char c;
 100         int i;
 101
 102         /* video rom */
 103         upper = adapter_rom_resources[0].start;
 104         for (start = video_rom_resource.start; start < upper; start += 2048) {
 105                 rom = isa_bus_to_virt(start);
 106                 if (!romsignature(rom))
 107                         continue;
 108
 109                 video_rom_resource.start = start;
 110
 111                 if (probe_kernel_address(rom + 2, c) != 0)
 112                         continue;
 113
 114                 /* 0 < length <= 0x7f * 512, historically */
 115                 length = c * 512;
 116
 117                 /* if checksum okay, trust length byte */
 118                 if (length && romchecksum(rom, length))
 119                         video_rom_resource.end = start + length - 1;
 120
 121                 request_resource(&iomem_resource, &video_rom_resource);
 122                 break;
 123         }
 124
 125         start = (video_rom_resource.end + 1 + 2047) & ~2047UL;
 126         if (start < upper)
 127                 start = upper;
 128
 129         /* system rom */
 130         request_resource(&iomem_resource, &system_rom_resource);
 131         upper = system_rom_resource.start;
 132
 133         /* check for extension rom (ignore length byte!) */
 134         rom = isa_bus_to_virt(extension_rom_resource.start);
 135         if (romsignature(rom)) {
 136                 length = extension_rom_resource.end - extension_rom_resource.start + 1;
 137                 if (romchecksum(rom, length)) {
 138                         request_resource(&iomem_resource, &extension_rom_resource);
 139                         upper = extension_rom_resource.start;
 140                 }
 141         }
 142
 143         /* check for adapter roms on 2k boundaries */
 144         for (i = 0; i < ARRAY_SIZE(adapter_rom_resources) && start < upper; start += 2048) {
 145                 rom = isa_bus_to_virt(start);
 146                 if (!romsignature(rom))
 147                         continue;
 148
 149                 if (probe_kernel_address(rom + 2, c) != 0)
 150                         continue;
 151
 152                 /* 0 < length <= 0x7f * 512, historically */
 153                 length = c * 512;
 154
 155                 /* but accept any length that fits if checksum okay */
 156                 if (!length || start + length > upper || !romchecksum(rom, length))
 157                         continue;
 158
 159                 adapter_rom_resources[i].start = start;
 160                 adapter_rom_resources[i].end = start + length - 1;
 161                 request_resource(&iomem_resource, &adapter_rom_resources[i]);
 162
 163                 start = adapter_rom_resources[i++].end & ~2047UL;
 164         }
 165 }
 166