drivers/pnp/pnpbios/bioscalls.c

   1 /*
   2  * bioscalls.c - the lowlevel layer of the PnPBIOS driver
   3  */
   4
   5 #include <linux/types.h>
   6 #include <linux/module.h>
   7 #include <linux/init.h>
   8 #include <linux/linkage.h>
   9 #include <linux/kernel.h>
  10 #include <linux/device.h>
  11 #include <linux/pnp.h>
  12 #include <linux/mm.h>
  13 #include <linux/smp.h>
  14 #include <linux/kmod.h>
  15 #include <linux/completion.h>
  16 #include <linux/spinlock.h>
  17
  18 #include <asm/page.h>
  19 #include <asm/desc.h>
  20 #include <asm/byteorder.h>
  21
  22 #include "pnpbios.h"
  23
  24 static struct {
  25         u16 offset;
  26         u16 segment;
  27 } pnp_bios_callpoint;
  28
  29 /*
  30  * These are some opcodes for a "static asmlinkage"
  31  * As this code is *not* executed inside the linux kernel segment, but in a
  32  * alias at offset 0, we need a far return that can not be compiled by
  33  * default (please, prove me wrong! this is *really* ugly!)
  34  * This is the only way to get the bios to return into the kernel code,
  35  * because the bios code runs in 16 bit protected mode and therefore can only
  36  * return to the caller if the call is within the first 64kB, and the linux
  37  * kernel begins at offset 3GB...
  38  */
  39
  40 asmlinkage void pnp_bios_callfunc(void);
  41
  42 __asm__(".text                  \n"
  43         __ALIGN_STR "\n"
  44         "pnp_bios_callfunc:\n"
  45         "       pushl %edx      \n"
  46         "       pushl %ecx      \n"
  47         "       pushl %ebx      \n"
  48         "       pushl %eax      \n"
  49         "       lcallw *pnp_bios_callpoint\n"
  50         "       addl $16, %esp  \n"
  51         "       lret            \n"
  52         ".previous              \n");
  53
  54 #define Q2_SET_SEL(cpu, selname, address, size) \
  55 do { \
  56         struct desc_struct *gdt = get_cpu_gdt_table((cpu)); \
  57         set_desc_base(&gdt[(selname) >> 3], (u32)(address)); \
  58         set_desc_limit(&gdt[(selname) >> 3], (size) - 1); \
  59 } while(0)
  60
  61 static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
  62                         (unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
  63
  64 /*
  65  * At some point we want to use this stack frame pointer to unwind
  66  * after PnP BIOS oopses.
  67  */
  68
  69 u32 pnp_bios_fault_esp;
  70 u32 pnp_bios_fault_eip;
  71 u32 pnp_bios_is_utter_crap = 0;
  72
  73 static spinlock_t pnp_bios_lock;
  74
  75 /*
  76  * Support Functions
  77  */
  78
  79 static inline u16 call_pnp_bios(u16 func, u16 arg1, u16 arg2, u16 arg3,
  80                                 u16 arg4, u16 arg5, u16 arg6, u16 arg7,
  81                                 void *ts1_base, u32 ts1_size,
  82                                 void *ts2_base, u32 ts2_size)
  83 {
  84         unsigned long flags;
  85         u16 status;
  86         struct desc_struct save_desc_40;
  87         int cpu;
  88
  89         /*
  90          * PnP BIOSes are generally not terribly re-entrant.
  91          * Also, don't rely on them to save everything correctly.
  92          */
  93         if (pnp_bios_is_utter_crap)
  94                 return PNP_FUNCTION_NOT_SUPPORTED;
  95
  96         cpu = get_cpu();
  97         save_desc_40 = get_cpu_gdt_table(cpu)[0x40 / 8];
  98         get_cpu_gdt_table(cpu)[0x40 / 8] = bad_bios_desc;
  99
 100         /* On some boxes IRQ's during PnP BIOS calls are deadly.  */
 101         spin_lock_irqsave(&pnp_bios_lock, flags);
 102
 103         /* The lock prevents us bouncing CPU here */
 104         if (ts1_size)
 105                 Q2_SET_SEL(smp_processor_id(), PNP_TS1, ts1_base, ts1_size);
 106         if (ts2_size)
 107                 Q2_SET_SEL(smp_processor_id(), PNP_TS2, ts2_base, ts2_size);
 108
 109         __asm__ __volatile__("pushl %%ebp\n\t"
 110                              "pushl %%edi\n\t"
 111                              "pushl %%esi\n\t"
 112                              "pushl %%ds\n\t"
 113                              "pushl %%es\n\t"
 114                              "pushl %%fs\n\t"
 115                              "pushl %%gs\n\t"
 116                              "pushfl\n\t"
 117                              "movl %%esp, pnp_bios_fault_esp\n\t"
 118                              "movl $1f, pnp_bios_fault_eip\n\t"
 119                              "lcall %5,%6\n\t"
 120                              "1:popfl\n\t"
 121                              "popl %%gs\n\t"
 122                              "popl %%fs\n\t"
 123                              "popl %%es\n\t"
 124                              "popl %%ds\n\t"
 125                              "popl %%esi\n\t"
 126                              "popl %%edi\n\t"
 127                              "popl %%ebp\n\t":"=a"(status)
 128                              :"0"((func) | (((u32) arg1) << 16)),
 129                              "b"((arg2) | (((u32) arg3) << 16)),
 130                              "c"((arg4) | (((u32) arg5) << 16)),
 131                              "d"((arg6) | (((u32) arg7) << 16)),
 132                              "i"(PNP_CS32), "i"(0)
 133                              :"memory");
 134         spin_unlock_irqrestore(&pnp_bios_lock, flags);
 135
 136         get_cpu_gdt_table(cpu)[0x40 / 8] = save_desc_40;
 137         put_cpu();
 138
 139         /* If we get here and this is set then the PnP BIOS faulted on us. */
 140         if (pnp_bios_is_utter_crap) {
 141                 printk(KERN_ERR
 142                        "PnPBIOS: Warning! Your PnP BIOS caused a fatal error. Attempting to continue\n");
 143                 printk(KERN_ERR
 144                        "PnPBIOS: You may need to reboot with the \"pnpbios=off\" option to operate stably\n");
 145                 printk(KERN_ERR
 146                        "PnPBIOS: Check with your vendor for an updated BIOS\n");
 147         }
 148
 149         return status;
 150 }
 151
 152 void pnpbios_print_status(const char *module, u16 status)
 153 {
 154         switch (status) {
 155         case PNP_SUCCESS:
 156                 printk(KERN_ERR "PnPBIOS: %s: function successful\n", module);
 157                 break;
 158         case PNP_NOT_SET_STATICALLY:
 159                 printk(KERN_ERR "PnPBIOS: %s: unable to set static resources\n",
 160                        module);
 161                 break;
 162         case PNP_UNKNOWN_FUNCTION:
 163                 printk(KERN_ERR "PnPBIOS: %s: invalid function number passed\n",
 164                        module);
 165                 break;
 166         case PNP_FUNCTION_NOT_SUPPORTED:
 167                 printk(KERN_ERR
 168                        "PnPBIOS: %s: function not supported on this system\n",
 169                        module);
 170                 break;
 171         case PNP_INVALID_HANDLE:
 172                 printk(KERN_ERR "PnPBIOS: %s: invalid handle\n", module);
 173                 break;
 174         case PNP_BAD_PARAMETER:
 175                 printk(KERN_ERR "PnPBIOS: %s: invalid parameters were passed\n",
 176                        module);
 177                 break;
 178         case PNP_SET_FAILED:
 179                 printk(KERN_ERR "PnPBIOS: %s: unable to set resources\n",
 180                        module);
 181                 break;
 182         case PNP_EVENTS_NOT_PENDING:
 183                 printk(KERN_ERR "PnPBIOS: %s: no events are pending\n", module);
 184                 break;
 185         case PNP_SYSTEM_NOT_DOCKED:
 186                 printk(KERN_ERR "PnPBIOS: %s: the system is not docked\n",
 187                        module);
 188                 break;
 189         case PNP_NO_ISA_PNP_CARDS:
 190                 printk(KERN_ERR
 191                        "PnPBIOS: %s: no isapnp cards are installed on this system\n",
 192                        module);
 193                 break;
 194         case PNP_UNABLE_TO_DETERMINE_DOCK_CAPABILITIES:
 195                 printk(KERN_ERR
 196                        "PnPBIOS: %s: cannot determine the capabilities of the docking station\n",
 197                        module);
 198                 break;
 199         case PNP_CONFIG_CHANGE_FAILED_NO_BATTERY:
 200                 printk(KERN_ERR
 201                        "PnPBIOS: %s: unable to undock, the system does not have a battery\n",
 202                        module);
 203                 break;
 204         case PNP_CONFIG_CHANGE_FAILED_RESOURCE_CONFLICT:
 205                 printk(KERN_ERR
 206                        "PnPBIOS: %s: could not dock due to resource conflicts\n",
 207                        module);
 208                 break;
 209         case PNP_BUFFER_TOO_SMALL:
 210                 printk(KERN_ERR "PnPBIOS: %s: the buffer passed is too small\n",
 211                        module);
 212                 break;
 213         case PNP_USE_ESCD_SUPPORT:
 214                 printk(KERN_ERR "PnPBIOS: %s: use ESCD instead\n", module);
 215                 break;
 216         case PNP_MESSAGE_NOT_SUPPORTED:
 217                 printk(KERN_ERR "PnPBIOS: %s: the message is unsupported\n",
 218                        module);
 219                 break;
 220         case PNP_HARDWARE_ERROR:
 221                 printk(KERN_ERR "PnPBIOS: %s: a hardware failure has occurred\n",
 222                        module);
 223                 break;
 224         default:
 225                 printk(KERN_ERR "PnPBIOS: %s: unexpected status 0x%x\n", module,
 226                        status);
 227                 break;
 228         }
 229 }
 230
 231 /*
 232  * PnP BIOS Low Level Calls
 233  */
 234
 235 #define PNP_GET_NUM_SYS_DEV_NODES               0x00
 236 #define PNP_GET_SYS_DEV_NODE                    0x01
 237 #define PNP_SET_SYS_DEV_NODE                    0x02
 238 #define PNP_GET_EVENT                           0x03
 239 #define PNP_SEND_MESSAGE                        0x04
 240 #define PNP_GET_DOCKING_STATION_INFORMATION     0x05
 241 #define PNP_SET_STATIC_ALLOCED_RES_INFO         0x09
 242 #define PNP_GET_STATIC_ALLOCED_RES_INFO         0x0a
 243 #define PNP_GET_APM_ID_TABLE                    0x0b
 244 #define PNP_GET_PNP_ISA_CONFIG_STRUC            0x40
 245 #define PNP_GET_ESCD_INFO                       0x41
 246 #define PNP_READ_ESCD                           0x42
 247 #define PNP_WRITE_ESCD                          0x43
 248
 249 /*
 250  * Call PnP BIOS with function 0x00, "get number of system device nodes"
 251  */
 252 static int __pnp_bios_dev_node_info(struct pnp_dev_node_info *data)
 253 {
 254         u16 status;
 255
 256         if (!pnp_bios_present())
 257                 return PNP_FUNCTION_NOT_SUPPORTED;
 258         status = call_pnp_bios(PNP_GET_NUM_SYS_DEV_NODES, 0, PNP_TS1, 2,
 259                                PNP_TS1, PNP_DS, 0, 0, data,
 260                                sizeof(struct pnp_dev_node_info), NULL, 0);
 261         data->no_nodes &= 0xff;
 262         return status;
 263 }
 264
 265 int pnp_bios_dev_node_info(struct pnp_dev_node_info *data)
 266 {
 267         int status = __pnp_bios_dev_node_info(data);
 268
 269         if (status)
 270                 pnpbios_print_status("dev_node_info", status);
 271         return status;
 272 }
 273
 274 /*
 275  * Note that some PnP BIOSes (e.g., on Sony Vaio laptops) die a horrible
 276  * death if they are asked to access the "current" configuration.
 277  * Therefore, if it's a matter of indifference, it's better to call
 278  * get_dev_node() and set_dev_node() with boot=1 rather than with boot=0.
 279  */
 280
 281 /*
 282  * Call PnP BIOS with function 0x01, "get system device node"
 283  * Input: *nodenum = desired node,
 284  *        boot = whether to get nonvolatile boot (!=0)
 285  *               or volatile current (0) config
 286  * Output: *nodenum=next node or 0xff if no more nodes
 287  */
 288 static int __pnp_bios_get_dev_node(u8 *nodenum, char boot,
 289                                    struct pnp_bios_node *data)
 290 {
 291         u16 status;
 292         u16 tmp_nodenum;
 293
 294         if (!pnp_bios_present())
 295                 return PNP_FUNCTION_NOT_SUPPORTED;
 296         if (!boot && pnpbios_dont_use_current_config)
 297                 return PNP_FUNCTION_NOT_SUPPORTED;
 298         tmp_nodenum = *nodenum;
 299         status = call_pnp_bios(PNP_GET_SYS_DEV_NODE, 0, PNP_TS1, 0, PNP_TS2,
 300                                boot ? 2 : 1, PNP_DS, 0, &tmp_nodenum,
 301                                sizeof(tmp_nodenum), data, 65536);
 302         *nodenum = tmp_nodenum;
 303         return status;
 304 }
 305
 306 int pnp_bios_get_dev_node(u8 *nodenum, char boot, struct pnp_bios_node *data)
 307 {
 308         int status;
 309
 310         status = __pnp_bios_get_dev_node(nodenum, boot, data);
 311         if (status)
 312                 pnpbios_print_status("get_dev_node", status);
 313         return status;
 314 }
 315
 316 /*
 317  * Call PnP BIOS with function 0x02, "set system device node"
 318  * Input: *nodenum = desired node,
 319  *        boot = whether to set nonvolatile boot (!=0)
 320  *               or volatile current (0) config
 321  */
 322 static int __pnp_bios_set_dev_node(u8 nodenum, char boot,
 323                                    struct pnp_bios_node *data)
 324 {
 325         u16 status;
 326
 327         if (!pnp_bios_present())
 328                 return PNP_FUNCTION_NOT_SUPPORTED;
 329         if (!boot && pnpbios_dont_use_current_config)
 330                 return PNP_FUNCTION_NOT_SUPPORTED;
 331         status = call_pnp_bios(PNP_SET_SYS_DEV_NODE, nodenum, 0, PNP_TS1,
 332                                boot ? 2 : 1, PNP_DS, 0, 0, data, 65536, NULL,
 333                                0);
 334         return status;
 335 }
 336
 337 int pnp_bios_set_dev_node(u8 nodenum, char boot, struct pnp_bios_node *data)
 338 {
 339         int status;
 340
 341         status = __pnp_bios_set_dev_node(nodenum, boot, data);
 342         if (status) {
 343                 pnpbios_print_status("set_dev_node", status);
 344                 return status;
 345         }
 346         if (!boot) {            /* Update devlist */
 347                 status = pnp_bios_get_dev_node(&nodenum, boot, data);
 348                 if (status)
 349                         return status;
 350         }
 351         return status;
 352 }
 353
 354 /*
 355  * Call PnP BIOS with function 0x05, "get docking station information"
 356  */
 357 int pnp_bios_dock_station_info(struct pnp_docking_station_info *data)
 358 {
 359         u16 status;
 360
 361         if (!pnp_bios_present())
 362                 return PNP_FUNCTION_NOT_SUPPORTED;
 363         status = call_pnp_bios(PNP_GET_DOCKING_STATION_INFORMATION, 0, PNP_TS1,
 364                                PNP_DS, 0, 0, 0, 0, data,
 365                                sizeof(struct pnp_docking_station_info), NULL,
 366                                0);
 367         return status;
 368 }
 369
 370 /*
 371  * Call PnP BIOS with function 0x0a, "get statically allocated resource
 372  * information"
 373  */
 374 static int __pnp_bios_get_stat_res(char *info)
 375 {
 376         u16 status;
 377
 378         if (!pnp_bios_present())
 379                 return PNP_FUNCTION_NOT_SUPPORTED;
 380         status = call_pnp_bios(PNP_GET_STATIC_ALLOCED_RES_INFO, 0, PNP_TS1,
 381                                PNP_DS, 0, 0, 0, 0, info, 65536, NULL, 0);
 382         return status;
 383 }
 384
 385 int pnp_bios_get_stat_res(char *info)
 386 {
 387         int status;
 388
 389         status = __pnp_bios_get_stat_res(info);
 390         if (status)
 391                 pnpbios_print_status("get_stat_res", status);
 392         return status;
 393 }
 394
 395 /*
 396  * Call PnP BIOS with function 0x40, "get isa pnp configuration structure"
 397  */
 398 static int __pnp_bios_isapnp_config(struct pnp_isa_config_struc *data)
 399 {
 400         u16 status;
 401
 402         if (!pnp_bios_present())
 403                 return PNP_FUNCTION_NOT_SUPPORTED;
 404         status = call_pnp_bios(PNP_GET_PNP_ISA_CONFIG_STRUC, 0, PNP_TS1, PNP_DS,
 405                                0, 0, 0, 0, data,
 406                                sizeof(struct pnp_isa_config_struc), NULL, 0);
 407         return status;
 408 }
 409
 410 int pnp_bios_isapnp_config(struct pnp_isa_config_struc *data)
 411 {
 412         int status;
 413
 414         status = __pnp_bios_isapnp_config(data);
 415         if (status)
 416                 pnpbios_print_status("isapnp_config", status);
 417         return status;
 418 }
 419
 420 /*
 421  * Call PnP BIOS with function 0x41, "get ESCD info"
 422  */
 423 static int __pnp_bios_escd_info(struct escd_info_struc *data)
 424 {
 425         u16 status;
 426
 427         if (!pnp_bios_present())
 428                 return ESCD_FUNCTION_NOT_SUPPORTED;
 429         status = call_pnp_bios(PNP_GET_ESCD_INFO, 0, PNP_TS1, 2, PNP_TS1, 4,
 430                                PNP_TS1, PNP_DS, data,
 431                                sizeof(struct escd_info_struc), NULL, 0);
 432         return status;
 433 }
 434
 435 int pnp_bios_escd_info(struct escd_info_struc *data)
 436 {
 437         int status;
 438
 439         status = __pnp_bios_escd_info(data);
 440         if (status)
 441                 pnpbios_print_status("escd_info", status);
 442         return status;
 443 }
 444
 445 /*
 446  * Call PnP BIOS function 0x42, "read ESCD"
 447  * nvram_base is determined by calling escd_info
 448  */
 449 static int __pnp_bios_read_escd(char *data, u32 nvram_base)
 450 {
 451         u16 status;
 452
 453         if (!pnp_bios_present())
 454                 return ESCD_FUNCTION_NOT_SUPPORTED;
 455         status = call_pnp_bios(PNP_READ_ESCD, 0, PNP_TS1, PNP_TS2, PNP_DS, 0, 0,
 456                                0, data, 65536, __va(nvram_base), 65536);
 457         return status;
 458 }
 459
 460 int pnp_bios_read_escd(char *data, u32 nvram_base)
 461 {
 462         int status;
 463
 464         status = __pnp_bios_read_escd(data, nvram_base);
 465         if (status)
 466                 pnpbios_print_status("read_escd", status);
 467         return status;
 468 }
 469
 470 void pnpbios_calls_init(union pnp_bios_install_struct *header)
 471 {
 472         int i;
 473
 474         spin_lock_init(&pnp_bios_lock);
 475         pnp_bios_callpoint.offset = header->fields.pm16offset;
 476         pnp_bios_callpoint.segment = PNP_CS16;
 477
 478         for_each_possible_cpu(i) {
 479                 struct desc_struct *gdt = get_cpu_gdt_table(i);
 480                 if (!gdt)
 481                         continue;
 482                 set_desc_base(&gdt[GDT_ENTRY_PNPBIOS_CS32],
 483                          (unsigned long)&pnp_bios_callfunc);
 484                 set_desc_base(&gdt[GDT_ENTRY_PNPBIOS_CS16],
 485                          (unsigned long)__va(header->fields.pm16cseg));
 486                 set_desc_base(&gdt[GDT_ENTRY_PNPBIOS_DS],
 487                          (unsigned long)__va(header->fields.pm16dseg));
 488         }
 489 }