drivers/mtd/maps/amd76xrom.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * amd76xrom.c
   4  *
   5  * Normal mappings of chips in physical memory
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/types.h>
  10 #include <linux/kernel.h>
  11 #include <linux/init.h>
  12 #include <linux/slab.h>
  13 #include <asm/io.h>
  14 #include <linux/mtd/mtd.h>
  15 #include <linux/mtd/map.h>
  16 #include <linux/mtd/cfi.h>
  17 #include <linux/mtd/flashchip.h>
  18 #include <linux/pci.h>
  19 #include <linux/pci_ids.h>
  20 #include <linux/list.h>
  21
  22
  23 #define xstr(s) str(s)
  24 #define str(s) #s
  25 #define MOD_NAME xstr(KBUILD_BASENAME)
  26
  27 #define ADDRESS_NAME_LEN 18
  28
  29 #define ROM_PROBE_STEP_SIZE (64*1024) /* 64KiB */
  30
  31 struct amd76xrom_window {
  32         void __iomem *virt;
  33         unsigned long phys;
  34         unsigned long size;
  35         struct list_head maps;
  36         struct resource rsrc;
  37         struct pci_dev *pdev;
  38 };
  39
  40 struct amd76xrom_map_info {
  41         struct list_head list;
  42         struct map_info map;
  43         struct mtd_info *mtd;
  44         struct resource rsrc;
  45         char map_name[sizeof(MOD_NAME) + 2 + ADDRESS_NAME_LEN];
  46 };
  47
  48 /* The 2 bits controlling the window size are often set to allow reading
  49  * the BIOS, but too small to allow writing, since the lock registers are
  50  * 4MiB lower in the address space than the data.
  51  *
  52  * This is intended to prevent flashing the bios, perhaps accidentally.
  53  *
  54  * This parameter allows the normal driver to over-ride the BIOS settings.
  55  *
  56  * The bits are 6 and 7.  If both bits are set, it is a 5MiB window.
  57  * If only the 7 Bit is set, it is a 4MiB window.  Otherwise, a
  58  * 64KiB window.
  59  *
  60  */
  61 static uint win_size_bits;
  62 module_param(win_size_bits, uint, 0);
  63 MODULE_PARM_DESC(win_size_bits, "ROM window size bits override for 0x43 byte, normally set by BIOS.");
  64
  65 static struct amd76xrom_window amd76xrom_window = {
  66         .maps = LIST_HEAD_INIT(amd76xrom_window.maps),
  67 };
  68
  69 static void amd76xrom_cleanup(struct amd76xrom_window *window)
  70 {
  71         struct amd76xrom_map_info *map, *scratch;
  72         u8 byte;
  73
  74         if (window->pdev) {
  75                 /* Disable writes through the rom window */
  76                 pci_read_config_byte(window->pdev, 0x40, &byte);
  77                 pci_write_config_byte(window->pdev, 0x40, byte & ~1);
  78                 pci_dev_put(window->pdev);
  79         }
  80
  81         /* Free all of the mtd devices */
  82         list_for_each_entry_safe(map, scratch, &window->maps, list) {
  83                 if (map->rsrc.parent) {
  84                         release_resource(&map->rsrc);
  85                 }
  86                 mtd_device_unregister(map->mtd);
  87                 map_destroy(map->mtd);
  88                 list_del(&map->list);
  89                 kfree(map);
  90         }
  91         if (window->rsrc.parent)
  92                 release_resource(&window->rsrc);
  93
  94         if (window->virt) {
  95                 iounmap(window->virt);
  96                 window->virt = NULL;
  97                 window->phys = 0;
  98                 window->size = 0;
  99                 window->pdev = NULL;
 100         }
 101 }
 102
 103
 104 static int amd76xrom_init_one(struct pci_dev *pdev,
 105                               const struct pci_device_id *ent)
 106 {
 107         static char *rom_probe_types[] = { "cfi_probe", "jedec_probe", NULL };
 108         u8 byte;
 109         struct amd76xrom_window *window = &amd76xrom_window;
 110         struct amd76xrom_map_info *map = NULL;
 111         unsigned long map_top;
 112
 113         /* Remember the pci dev I find the window in - already have a ref */
 114         window->pdev = pdev;
 115
 116         /* Enable the selected rom window.  This is often incorrectly
 117          * set up by the BIOS, and the 4MiB offset for the lock registers
 118          * requires the full 5MiB of window space.
 119          *
 120          * This 'write, then read' approach leaves the bits for
 121          * other uses of the hardware info.
 122          */
 123         pci_read_config_byte(pdev, 0x43, &byte);
 124         pci_write_config_byte(pdev, 0x43, byte | win_size_bits );
 125
 126         /* Assume the rom window is properly setup, and find it's size */
 127         pci_read_config_byte(pdev, 0x43, &byte);
 128         if ((byte & ((1<<7)|(1<<6))) == ((1<<7)|(1<<6))) {
 129                 window->phys = 0xffb00000; /* 5MiB */
 130         }
 131         else if ((byte & (1<<7)) == (1<<7)) {
 132                 window->phys = 0xffc00000; /* 4MiB */
 133         }
 134         else {
 135                 window->phys = 0xffff0000; /* 64KiB */
 136         }
 137         window->size = 0xffffffffUL - window->phys + 1UL;
 138
 139         /*
 140          * Try to reserve the window mem region.  If this fails then
 141          * it is likely due to a fragment of the window being
 142          * "reserved" by the BIOS.  In the case that the
 143          * request_mem_region() fails then once the rom size is
 144          * discovered we will try to reserve the unreserved fragment.
 145          */
 146         window->rsrc.name = MOD_NAME;
 147         window->rsrc.start = window->phys;
 148         window->rsrc.end   = window->phys + window->size - 1;
 149         window->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 150         if (request_resource(&iomem_resource, &window->rsrc)) {
 151                 window->rsrc.parent = NULL;
 152                 printk(KERN_ERR MOD_NAME
 153                        " %s(): Unable to register resource %pR - kernel bug?\n",
 154                        __func__, &window->rsrc);
 155                 return -EBUSY;
 156         }
 157
 158
 159         /* Enable writes through the rom window */
 160         pci_read_config_byte(pdev, 0x40, &byte);
 161         pci_write_config_byte(pdev, 0x40, byte | 1);
 162
 163         /* FIXME handle registers 0x80 - 0x8C the bios region locks */
 164
 165         /* For write accesses caches are useless */
 166         window->virt = ioremap(window->phys, window->size);
 167         if (!window->virt) {
 168                 printk(KERN_ERR MOD_NAME ": ioremap(%08lx, %08lx) failed\n",
 169                         window->phys, window->size);
 170                 goto out;
 171         }
 172
 173         /* Get the first address to look for an rom chip at */
 174         map_top = window->phys;
 175 #if 1
 176         /* The probe sequence run over the firmware hub lock
 177          * registers sets them to 0x7 (no access).
 178          * Probe at most the last 4M of the address space.
 179          */
 180         if (map_top < 0xffc00000) {
 181                 map_top = 0xffc00000;
 182         }
 183 #endif
 184         /* Loop  through and look for rom chips */
 185         while((map_top - 1) < 0xffffffffUL) {
 186                 struct cfi_private *cfi;
 187                 unsigned long offset;
 188                 int i;
 189
 190                 if (!map) {
 191                         map = kmalloc(sizeof(*map), GFP_KERNEL);
 192                 }
 193                 if (!map) {
 194                         printk(KERN_ERR MOD_NAME ": kmalloc failed");
 195                         goto out;
 196                 }
 197                 memset(map, 0, sizeof(*map));
 198                 INIT_LIST_HEAD(&map->list);
 199                 map->map.name = map->map_name;
 200                 map->map.phys = map_top;
 201                 offset = map_top - window->phys;
 202                 map->map.virt = (void __iomem *)
 203                         (((unsigned long)(window->virt)) + offset);
 204                 map->map.size = 0xffffffffUL - map_top + 1UL;
 205                 /* Set the name of the map to the address I am trying */
 206                 sprintf(map->map_name, "%s @%08Lx",
 207                         MOD_NAME, (unsigned long long)map->map.phys);
 208
 209                 /* There is no generic VPP support */
 210                 for(map->map.bankwidth = 32; map->map.bankwidth;
 211                         map->map.bankwidth >>= 1)
 212                 {
 213                         char **probe_type;
 214                         /* Skip bankwidths that are not supported */
 215                         if (!map_bankwidth_supported(map->map.bankwidth))
 216                                 continue;
 217
 218                         /* Setup the map methods */
 219                         simple_map_init(&map->map);
 220
 221                         /* Try all of the probe methods */
 222                         probe_type = rom_probe_types;
 223                         for(; *probe_type; probe_type++) {
 224                                 map->mtd = do_map_probe(*probe_type, &map->map);
 225                                 if (map->mtd)
 226                                         goto found;
 227                         }
 228                 }
 229                 map_top += ROM_PROBE_STEP_SIZE;
 230                 continue;
 231         found:
 232                 /* Trim the size if we are larger than the map */
 233                 if (map->mtd->size > map->map.size) {
 234                         printk(KERN_WARNING MOD_NAME
 235                                 " rom(%llu) larger than window(%lu). fixing...\n",
 236                                 (unsigned long long)map->mtd->size, map->map.size);
 237                         map->mtd->size = map->map.size;
 238                 }
 239                 if (window->rsrc.parent) {
 240                         /*
 241                          * Registering the MTD device in iomem may not be possible
 242                          * if there is a BIOS "reserved" and BUSY range.  If this
 243                          * fails then continue anyway.
 244                          */
 245                         map->rsrc.name  = map->map_name;
 246                         map->rsrc.start = map->map.phys;
 247                         map->rsrc.end   = map->map.phys + map->mtd->size - 1;
 248                         map->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 249                         if (request_resource(&window->rsrc, &map->rsrc)) {
 250                                 printk(KERN_ERR MOD_NAME
 251                                         ": cannot reserve MTD resource\n");
 252                                 map->rsrc.parent = NULL;
 253                         }
 254                 }
 255
 256                 /* Make the whole region visible in the map */
 257                 map->map.virt = window->virt;
 258                 map->map.phys = window->phys;
 259                 cfi = map->map.fldrv_priv;
 260                 for(i = 0; i < cfi->numchips; i++) {
 261                         cfi->chips[i].start += offset;
 262                 }
 263
 264                 /* Now that the mtd devices is complete claim and export it */
 265                 map->mtd->owner = THIS_MODULE;
 266                 if (mtd_device_register(map->mtd, NULL, 0)) {
 267                         map_destroy(map->mtd);
 268                         map->mtd = NULL;
 269                         goto out;
 270                 }
 271
 272
 273                 /* Calculate the new value of map_top */
 274                 map_top += map->mtd->size;
 275
 276                 /* File away the map structure */
 277                 list_add(&map->list, &window->maps);
 278                 map = NULL;
 279         }
 280
 281  out:
 282         /* Free any left over map structures */
 283         kfree(map);
 284         /* See if I have any map structures */
 285         if (list_empty(&window->maps)) {
 286                 amd76xrom_cleanup(window);
 287                 return -ENODEV;
 288         }
 289         return 0;
 290 }
 291
 292
 293 static void amd76xrom_remove_one(struct pci_dev *pdev)
 294 {
 295         struct amd76xrom_window *window = &amd76xrom_window;
 296
 297         amd76xrom_cleanup(window);
 298 }
 299
 300 static const struct pci_device_id amd76xrom_pci_tbl[] = {
 301         { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_7410,
 302                 PCI_ANY_ID, PCI_ANY_ID, },
 303         { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_7440,
 304                 PCI_ANY_ID, PCI_ANY_ID, },
 305         { PCI_VENDOR_ID_AMD, 0x7468 }, /* amd8111 support */
 306         { 0, }
 307 };
 308
 309 MODULE_DEVICE_TABLE(pci, amd76xrom_pci_tbl);
 310
 311 #if 0
 312 static struct pci_driver amd76xrom_driver = {
 313         .name =         MOD_NAME,
 314         .id_table =     amd76xrom_pci_tbl,
 315         .probe =        amd76xrom_init_one,
 316         .remove =       amd76xrom_remove_one,
 317 };
 318 #endif
 319
 320 static int __init init_amd76xrom(void)
 321 {
 322         struct pci_dev *pdev;
 323         const struct pci_device_id *id;
 324         pdev = NULL;
 325         for(id = amd76xrom_pci_tbl; id->vendor; id++) {
 326                 pdev = pci_get_device(id->vendor, id->device, NULL);
 327                 if (pdev) {
 328                         break;
 329                 }
 330         }
 331         if (pdev) {
 332                 return amd76xrom_init_one(pdev, &amd76xrom_pci_tbl[0]);
 333         }
 334         return -ENXIO;
 335 #if 0
 336         return pci_register_driver(&amd76xrom_driver);
 337 #endif
 338 }
 339
 340 static void __exit cleanup_amd76xrom(void)
 341 {
 342         amd76xrom_remove_one(amd76xrom_window.pdev);
 343 }
 344
 345 module_init(init_amd76xrom);
 346 module_exit(cleanup_amd76xrom);
 347
 348 MODULE_LICENSE("GPL");
 349 MODULE_AUTHOR("Eric Biederman <ebiederman@lnxi.com>");
 350 MODULE_DESCRIPTION("MTD map driver for BIOS chips on the AMD76X southbridge");