arch/x86/kernel/probe_roms.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 /* does this oprom support the given pci device, or any of the devices
  77  * that the driver supports?
  78  */
  79 static bool match_id(struct pci_dev *pdev, unsigned short vendor, unsigned short device)
  80 {
  81         struct pci_driver *drv = pdev->driver;
  82         const struct pci_device_id *id;
  83
  84         if (pdev->vendor == vendor && pdev->device == device)
  85                 return true;
  86
  87         for (id = drv ? drv->id_table : NULL; id && id->vendor; id++)
  88                 if (id->vendor == vendor && id->device == device)
  89                         break;
  90
  91         return id && id->vendor;
  92 }
  93
  94 static bool probe_list(struct pci_dev *pdev, unsigned short vendor,
  95                        const unsigned char *rom_list)
  96 {
  97         unsigned short device;
  98
  99         do {
 100                 if (probe_kernel_address(rom_list, device) != 0)
 101                         device = 0;
 102
 103                 if (device && match_id(pdev, vendor, device))
 104                         break;
 105
 106                 rom_list += 2;
 107         } while (device);
 108
 109         return !!device;
 110 }
 111
 112 static struct resource *find_oprom(struct pci_dev *pdev)
 113 {
 114         struct resource *oprom = NULL;
 115         int i;
 116
 117         for (i = 0; i < ARRAY_SIZE(adapter_rom_resources); i++) {
 118                 struct resource *res = &adapter_rom_resources[i];
 119                 unsigned short offset, vendor, device, list, rev;
 120                 const unsigned char *rom;
 121
 122                 if (res->end == 0)
 123                         break;
 124
 125                 rom = isa_bus_to_virt(res->start);
 126                 if (probe_kernel_address(rom + 0x18, offset) != 0)
 127                         continue;
 128
 129                 if (probe_kernel_address(rom + offset + 0x4, vendor) != 0)
 130                         continue;
 131
 132                 if (probe_kernel_address(rom + offset + 0x6, device) != 0)
 133                         continue;
 134
 135                 if (match_id(pdev, vendor, device)) {
 136                         oprom = res;
 137                         break;
 138                 }
 139
 140                 if (probe_kernel_address(rom + offset + 0x8, list) == 0 &&
 141                     probe_kernel_address(rom + offset + 0xc, rev) == 0 &&
 142                     rev >= 3 && list &&
 143                     probe_list(pdev, vendor, rom + offset + list)) {
 144                         oprom = res;
 145                         break;
 146                 }
 147         }
 148
 149         return oprom;
 150 }
 151
 152 void *pci_map_biosrom(struct pci_dev *pdev)
 153 {
 154         struct resource *oprom = find_oprom(pdev);
 155
 156         if (!oprom)
 157                 return NULL;
 158
 159         return ioremap(oprom->start, resource_size(oprom));
 160 }
 161 EXPORT_SYMBOL(pci_map_biosrom);
 162
 163 void pci_unmap_biosrom(void __iomem *image)
 164 {
 165         iounmap(image);
 166 }
 167 EXPORT_SYMBOL(pci_unmap_biosrom);
 168
 169 size_t pci_biosrom_size(struct pci_dev *pdev)
 170 {
 171         struct resource *oprom = find_oprom(pdev);
 172
 173         return oprom ? resource_size(oprom) : 0;
 174 }
 175 EXPORT_SYMBOL(pci_biosrom_size);
 176
 177 #define ROMSIGNATURE 0xaa55
 178
 179 static int __init romsignature(const unsigned char *rom)
 180 {
 181         const unsigned short * const ptr = (const unsigned short *)rom;
 182         unsigned short sig;
 183
 184         return probe_kernel_address(ptr, sig) == 0 && sig == ROMSIGNATURE;
 185 }
 186
 187 static int __init romchecksum(const unsigned char *rom, unsigned long length)
 188 {
 189         unsigned char sum, c;
 190
 191         for (sum = 0; length && probe_kernel_address(rom++, c) == 0; length--)
 192                 sum += c;
 193         return !length && !sum;
 194 }
 195
 196 void __init probe_roms(void)
 197 {
 198         const unsigned char *rom;
 199         unsigned long start, length, upper;
 200         unsigned char c;
 201         int i;
 202
 203         /* video rom */
 204         upper = adapter_rom_resources[0].start;
 205         for (start = video_rom_resource.start; start < upper; start += 2048) {
 206                 rom = isa_bus_to_virt(start);
 207                 if (!romsignature(rom))
 208                         continue;
 209
 210                 video_rom_resource.start = start;
 211
 212                 if (probe_kernel_address(rom + 2, c) != 0)
 213                         continue;
 214
 215                 /* 0 < length <= 0x7f * 512, historically */
 216                 length = c * 512;
 217
 218                 /* if checksum okay, trust length byte */
 219                 if (length && romchecksum(rom, length))
 220                         video_rom_resource.end = start + length - 1;
 221
 222                 request_resource(&iomem_resource, &video_rom_resource);
 223                 break;
 224         }
 225
 226         start = (video_rom_resource.end + 1 + 2047) & ~2047UL;
 227         if (start < upper)
 228                 start = upper;
 229
 230         /* system rom */
 231         request_resource(&iomem_resource, &system_rom_resource);
 232         upper = system_rom_resource.start;
 233
 234         /* check for extension rom (ignore length byte!) */
 235         rom = isa_bus_to_virt(extension_rom_resource.start);
 236         if (romsignature(rom)) {
 237                 length = extension_rom_resource.end - extension_rom_resource.start + 1;
 238                 if (romchecksum(rom, length)) {
 239                         request_resource(&iomem_resource, &extension_rom_resource);
 240                         upper = extension_rom_resource.start;
 241                 }
 242         }
 243
 244         /* check for adapter roms on 2k boundaries */
 245         for (i = 0; i < ARRAY_SIZE(adapter_rom_resources) && start < upper; start += 2048) {
 246                 rom = isa_bus_to_virt(start);
 247                 if (!romsignature(rom))
 248                         continue;
 249
 250                 if (probe_kernel_address(rom + 2, c) != 0)
 251                         continue;
 252
 253                 /* 0 < length <= 0x7f * 512, historically */
 254                 length = c * 512;
 255
 256                 /* but accept any length that fits if checksum okay */
 257                 if (!length || start + length > upper || !romchecksum(rom, length))
 258                         continue;
 259
 260                 adapter_rom_resources[i].start = start;
 261                 adapter_rom_resources[i].end = start + length - 1;
 262                 request_resource(&iomem_resource, &adapter_rom_resources[i]);
 263
 264                 start = adapter_rom_resources[i++].end & ~2047UL;
 265         }
 266 }
 267