pnp/pnpbios/bioscalls.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * bioscalls.c - the lowlevel layer of the PnPBIOS driver
0004  */
0005
0006 #include <linux/types.h>
0007 #include <linux/module.h>
0008 #include <linux/init.h>
0009 #include <linux/linkage.h>
0010 #include <linux/kernel.h>
0011 #include <linux/device.h>
0012 #include <linux/pnp.h>
0013 #include <linux/mm.h>
0014 #include <linux/smp.h>
0015 #include <linux/kmod.h>
0016 #include <linux/completion.h>
0017 #include <linux/spinlock.h>
0018
0019 #include <asm/page.h>
0020 #include <asm/desc.h>
0021 #include <asm/byteorder.h>
0022
0023 #include "pnpbios.h"
0024
0025 __visible struct {
0026     u16 offset;
0027     u16 segment;
0028 } pnp_bios_callpoint;
0029
0030 /*
0031  * These are some opcodes for a "static asmlinkage"
0032  * As this code is *not* executed inside the linux kernel segment, but in a
0033  * alias at offset 0, we need a far return that can not be compiled by
0034  * default (please, prove me wrong! this is *really* ugly!)
0035  * This is the only way to get the bios to return into the kernel code,
0036  * because the bios code runs in 16 bit protected mode and therefore can only
0037  * return to the caller if the call is within the first 64kB, and the linux
0038  * kernel begins at offset 3GB...
0039  */
0040
0041 asmlinkage __visible void pnp_bios_callfunc(void);
0042
0043 __asm__(".text          \n"
0044     __ALIGN_STR "\n"
0045     ".globl pnp_bios_callfunc\n"
0046     "pnp_bios_callfunc:\n"
0047     "   pushl %edx  \n"
0048     "   pushl %ecx  \n"
0049     "   pushl %ebx  \n"
0050     "   pushl %eax  \n"
0051     "   lcallw *pnp_bios_callpoint\n"
0052     "   addl $16, %esp  \n"
0053     "   lret        \n"
0054     ".previous      \n");
0055
0056 #define Q2_SET_SEL(cpu, selname, address, size) \
0057 do { \
0058     struct desc_struct *gdt = get_cpu_gdt_rw((cpu)); \
0059     set_desc_base(&gdt[(selname) >> 3], (u32)(address)); \
0060     set_desc_limit(&gdt[(selname) >> 3], (size) - 1); \
0061 } while(0)
0062
0063 static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
0064             (unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
0065
0066 /*
0067  * At some point we want to use this stack frame pointer to unwind
0068  * after PnP BIOS oopses.
0069  */
0070
0071 __visible u32 pnp_bios_fault_esp;
0072 __visible u32 pnp_bios_fault_eip;
0073 __visible u32 pnp_bios_is_utter_crap = 0;
0074
0075 static DEFINE_SPINLOCK(pnp_bios_lock);
0076
0077 /*
0078  * Support Functions
0079  */
0080
0081 static inline u16 call_pnp_bios(u16 func, u16 arg1, u16 arg2, u16 arg3,
0082                 u16 arg4, u16 arg5, u16 arg6, u16 arg7,
0083                 void *ts1_base, u32 ts1_size,
0084                 void *ts2_base, u32 ts2_size)
0085 {
0086     unsigned long flags;
0087     u16 status;
0088     struct desc_struct save_desc_40;
0089     int cpu;
0090
0091     /*
0092      * PnP BIOSes are generally not terribly re-entrant.
0093      * Also, don't rely on them to save everything correctly.
0094      */
0095     if (pnp_bios_is_utter_crap)
0096         return PNP_FUNCTION_NOT_SUPPORTED;
0097
0098     cpu = get_cpu();
0099     save_desc_40 = get_cpu_gdt_rw(cpu)[0x40 / 8];
0100     get_cpu_gdt_rw(cpu)[0x40 / 8] = bad_bios_desc;
0101
0102     /* On some boxes IRQ's during PnP BIOS calls are deadly.  */
0103     spin_lock_irqsave(&pnp_bios_lock, flags);
0104
0105     /* The lock prevents us bouncing CPU here */
0106     if (ts1_size)
0107         Q2_SET_SEL(smp_processor_id(), PNP_TS1, ts1_base, ts1_size);
0108     if (ts2_size)
0109         Q2_SET_SEL(smp_processor_id(), PNP_TS2, ts2_base, ts2_size);
0110
0111     __asm__ __volatile__("pushl %%ebp\n\t"
0112                  "pushl %%edi\n\t"
0113                  "pushl %%esi\n\t"
0114                  "pushl %%ds\n\t"
0115                  "pushl %%es\n\t"
0116                  "pushl %%fs\n\t"
0117                  "pushl %%gs\n\t"
0118                  "pushfl\n\t"
0119                  "movl %%esp, pnp_bios_fault_esp\n\t"
0120                  "movl $1f, pnp_bios_fault_eip\n\t"
0121                  "lcall %5,%6\n\t"
0122                  "1:popfl\n\t"
0123                  "popl %%gs\n\t"
0124                  "popl %%fs\n\t"
0125                  "popl %%es\n\t"
0126                  "popl %%ds\n\t"
0127                  "popl %%esi\n\t"
0128                  "popl %%edi\n\t"
0129                  "popl %%ebp\n\t":"=a"(status)
0130                  :"0"((func) | (((u32) arg1) << 16)),
0131                  "b"((arg2) | (((u32) arg3) << 16)),
0132                  "c"((arg4) | (((u32) arg5) << 16)),
0133                  "d"((arg6) | (((u32) arg7) << 16)),
0134                  "i"(PNP_CS32), "i"(0)
0135                  :"memory");
0136     spin_unlock_irqrestore(&pnp_bios_lock, flags);
0137
0138     get_cpu_gdt_rw(cpu)[0x40 / 8] = save_desc_40;
0139     put_cpu();
0140
0141     /* If we get here and this is set then the PnP BIOS faulted on us. */
0142     if (pnp_bios_is_utter_crap) {
0143         printk(KERN_ERR
0144                "PnPBIOS: Warning! Your PnP BIOS caused a fatal error. Attempting to continue\n");
0145         printk(KERN_ERR
0146                "PnPBIOS: You may need to reboot with the \"pnpbios=off\" option to operate stably\n");
0147         printk(KERN_ERR
0148                "PnPBIOS: Check with your vendor for an updated BIOS\n");
0149     }
0150
0151     return status;
0152 }
0153
0154 void pnpbios_print_status(const char *module, u16 status)
0155 {
0156     switch (status) {
0157     case PNP_SUCCESS:
0158         printk(KERN_ERR "PnPBIOS: %s: function successful\n", module);
0159         break;
0160     case PNP_NOT_SET_STATICALLY:
0161         printk(KERN_ERR "PnPBIOS: %s: unable to set static resources\n",
0162                module);
0163         break;
0164     case PNP_UNKNOWN_FUNCTION:
0165         printk(KERN_ERR "PnPBIOS: %s: invalid function number passed\n",
0166                module);
0167         break;
0168     case PNP_FUNCTION_NOT_SUPPORTED:
0169         printk(KERN_ERR
0170                "PnPBIOS: %s: function not supported on this system\n",
0171                module);
0172         break;
0173     case PNP_INVALID_HANDLE:
0174         printk(KERN_ERR "PnPBIOS: %s: invalid handle\n", module);
0175         break;
0176     case PNP_BAD_PARAMETER:
0177         printk(KERN_ERR "PnPBIOS: %s: invalid parameters were passed\n",
0178                module);
0179         break;
0180     case PNP_SET_FAILED:
0181         printk(KERN_ERR "PnPBIOS: %s: unable to set resources\n",
0182                module);
0183         break;
0184     case PNP_EVENTS_NOT_PENDING:
0185         printk(KERN_ERR "PnPBIOS: %s: no events are pending\n", module);
0186         break;
0187     case PNP_SYSTEM_NOT_DOCKED:
0188         printk(KERN_ERR "PnPBIOS: %s: the system is not docked\n",
0189                module);
0190         break;
0191     case PNP_NO_ISA_PNP_CARDS:
0192         printk(KERN_ERR
0193                "PnPBIOS: %s: no isapnp cards are installed on this system\n",
0194                module);
0195         break;
0196     case PNP_UNABLE_TO_DETERMINE_DOCK_CAPABILITIES:
0197         printk(KERN_ERR
0198                "PnPBIOS: %s: cannot determine the capabilities of the docking station\n",
0199                module);
0200         break;
0201     case PNP_CONFIG_CHANGE_FAILED_NO_BATTERY:
0202         printk(KERN_ERR
0203                "PnPBIOS: %s: unable to undock, the system does not have a battery\n",
0204                module);
0205         break;
0206     case PNP_CONFIG_CHANGE_FAILED_RESOURCE_CONFLICT:
0207         printk(KERN_ERR
0208                "PnPBIOS: %s: could not dock due to resource conflicts\n",
0209                module);
0210         break;
0211     case PNP_BUFFER_TOO_SMALL:
0212         printk(KERN_ERR "PnPBIOS: %s: the buffer passed is too small\n",
0213                module);
0214         break;
0215     case PNP_USE_ESCD_SUPPORT:
0216         printk(KERN_ERR "PnPBIOS: %s: use ESCD instead\n", module);
0217         break;
0218     case PNP_MESSAGE_NOT_SUPPORTED:
0219         printk(KERN_ERR "PnPBIOS: %s: the message is unsupported\n",
0220                module);
0221         break;
0222     case PNP_HARDWARE_ERROR:
0223         printk(KERN_ERR "PnPBIOS: %s: a hardware failure has occurred\n",
0224                module);
0225         break;
0226     default:
0227         printk(KERN_ERR "PnPBIOS: %s: unexpected status 0x%x\n", module,
0228                status);
0229         break;
0230     }
0231 }
0232
0233 /*
0234  * PnP BIOS Low Level Calls
0235  */
0236
0237 #define PNP_GET_NUM_SYS_DEV_NODES       0x00
0238 #define PNP_GET_SYS_DEV_NODE            0x01
0239 #define PNP_SET_SYS_DEV_NODE            0x02
0240 #define PNP_GET_EVENT               0x03
0241 #define PNP_SEND_MESSAGE            0x04
0242 #define PNP_GET_DOCKING_STATION_INFORMATION 0x05
0243 #define PNP_SET_STATIC_ALLOCED_RES_INFO     0x09
0244 #define PNP_GET_STATIC_ALLOCED_RES_INFO     0x0a
0245 #define PNP_GET_APM_ID_TABLE            0x0b
0246 #define PNP_GET_PNP_ISA_CONFIG_STRUC        0x40
0247 #define PNP_GET_ESCD_INFO           0x41
0248 #define PNP_READ_ESCD               0x42
0249 #define PNP_WRITE_ESCD              0x43
0250
0251 /*
0252  * Call PnP BIOS with function 0x00, "get number of system device nodes"
0253  */
0254 static int __pnp_bios_dev_node_info(struct pnp_dev_node_info *data)
0255 {
0256     u16 status;
0257
0258     if (!pnp_bios_present())
0259         return PNP_FUNCTION_NOT_SUPPORTED;
0260     status = call_pnp_bios(PNP_GET_NUM_SYS_DEV_NODES, 0, PNP_TS1, 2,
0261                    PNP_TS1, PNP_DS, 0, 0, data,
0262                    sizeof(struct pnp_dev_node_info), NULL, 0);
0263     data->no_nodes &= 0xff;
0264     return status;
0265 }
0266
0267 int pnp_bios_dev_node_info(struct pnp_dev_node_info *data)
0268 {
0269     int status = __pnp_bios_dev_node_info(data);
0270
0271     if (status)
0272         pnpbios_print_status("dev_node_info", status);
0273     return status;
0274 }
0275
0276 /*
0277  * Note that some PnP BIOSes (e.g., on Sony Vaio laptops) die a horrible
0278  * death if they are asked to access the "current" configuration.
0279  * Therefore, if it's a matter of indifference, it's better to call
0280  * get_dev_node() and set_dev_node() with boot=1 rather than with boot=0.
0281  */
0282
0283 /*
0284  * Call PnP BIOS with function 0x01, "get system device node"
0285  * Input: *nodenum = desired node,
0286  *        boot = whether to get nonvolatile boot (!=0)
0287  *               or volatile current (0) config
0288  * Output: *nodenum=next node or 0xff if no more nodes
0289  */
0290 static int __pnp_bios_get_dev_node(u8 *nodenum, char boot,
0291                    struct pnp_bios_node *data)
0292 {
0293     u16 status;
0294     u16 tmp_nodenum;
0295
0296     if (!pnp_bios_present())
0297         return PNP_FUNCTION_NOT_SUPPORTED;
0298     if (!boot && pnpbios_dont_use_current_config)
0299         return PNP_FUNCTION_NOT_SUPPORTED;
0300     tmp_nodenum = *nodenum;
0301     status = call_pnp_bios(PNP_GET_SYS_DEV_NODE, 0, PNP_TS1, 0, PNP_TS2,
0302                    boot ? 2 : 1, PNP_DS, 0, &tmp_nodenum,
0303                    sizeof(tmp_nodenum), data, 65536);
0304     *nodenum = tmp_nodenum;
0305     return status;
0306 }
0307
0308 int pnp_bios_get_dev_node(u8 *nodenum, char boot, struct pnp_bios_node *data)
0309 {
0310     int status;
0311
0312     status = __pnp_bios_get_dev_node(nodenum, boot, data);
0313     if (status)
0314         pnpbios_print_status("get_dev_node", status);
0315     return status;
0316 }
0317
0318 /*
0319  * Call PnP BIOS with function 0x02, "set system device node"
0320  * Input: *nodenum = desired node,
0321  *        boot = whether to set nonvolatile boot (!=0)
0322  *               or volatile current (0) config
0323  */
0324 static int __pnp_bios_set_dev_node(u8 nodenum, char boot,
0325                    struct pnp_bios_node *data)
0326 {
0327     u16 status;
0328
0329     if (!pnp_bios_present())
0330         return PNP_FUNCTION_NOT_SUPPORTED;
0331     if (!boot && pnpbios_dont_use_current_config)
0332         return PNP_FUNCTION_NOT_SUPPORTED;
0333     status = call_pnp_bios(PNP_SET_SYS_DEV_NODE, nodenum, 0, PNP_TS1,
0334                    boot ? 2 : 1, PNP_DS, 0, 0, data, 65536, NULL,
0335                    0);
0336     return status;
0337 }
0338
0339 int pnp_bios_set_dev_node(u8 nodenum, char boot, struct pnp_bios_node *data)
0340 {
0341     int status;
0342
0343     status = __pnp_bios_set_dev_node(nodenum, boot, data);
0344     if (status) {
0345         pnpbios_print_status("set_dev_node", status);
0346         return status;
0347     }
0348     if (!boot) {        /* Update devlist */
0349         status = pnp_bios_get_dev_node(&nodenum, boot, data);
0350         if (status)
0351             return status;
0352     }
0353     return status;
0354 }
0355
0356 /*
0357  * Call PnP BIOS with function 0x05, "get docking station information"
0358  */
0359 int pnp_bios_dock_station_info(struct pnp_docking_station_info *data)
0360 {
0361     u16 status;
0362
0363     if (!pnp_bios_present())
0364         return PNP_FUNCTION_NOT_SUPPORTED;
0365     status = call_pnp_bios(PNP_GET_DOCKING_STATION_INFORMATION, 0, PNP_TS1,
0366                    PNP_DS, 0, 0, 0, 0, data,
0367                    sizeof(struct pnp_docking_station_info), NULL,
0368                    0);
0369     return status;
0370 }
0371
0372 /*
0373  * Call PnP BIOS with function 0x0a, "get statically allocated resource
0374  * information"
0375  */
0376 static int __pnp_bios_get_stat_res(char *info)
0377 {
0378     u16 status;
0379
0380     if (!pnp_bios_present())
0381         return PNP_FUNCTION_NOT_SUPPORTED;
0382     status = call_pnp_bios(PNP_GET_STATIC_ALLOCED_RES_INFO, 0, PNP_TS1,
0383                    PNP_DS, 0, 0, 0, 0, info, 65536, NULL, 0);
0384     return status;
0385 }
0386
0387 int pnp_bios_get_stat_res(char *info)
0388 {
0389     int status;
0390
0391     status = __pnp_bios_get_stat_res(info);
0392     if (status)
0393         pnpbios_print_status("get_stat_res", status);
0394     return status;
0395 }
0396
0397 /*
0398  * Call PnP BIOS with function 0x40, "get isa pnp configuration structure"
0399  */
0400 static int __pnp_bios_isapnp_config(struct pnp_isa_config_struc *data)
0401 {
0402     u16 status;
0403
0404     if (!pnp_bios_present())
0405         return PNP_FUNCTION_NOT_SUPPORTED;
0406     status = call_pnp_bios(PNP_GET_PNP_ISA_CONFIG_STRUC, 0, PNP_TS1, PNP_DS,
0407                    0, 0, 0, 0, data,
0408                    sizeof(struct pnp_isa_config_struc), NULL, 0);
0409     return status;
0410 }
0411
0412 int pnp_bios_isapnp_config(struct pnp_isa_config_struc *data)
0413 {
0414     int status;
0415
0416     status = __pnp_bios_isapnp_config(data);
0417     if (status)
0418         pnpbios_print_status("isapnp_config", status);
0419     return status;
0420 }
0421
0422 /*
0423  * Call PnP BIOS with function 0x41, "get ESCD info"
0424  */
0425 static int __pnp_bios_escd_info(struct escd_info_struc *data)
0426 {
0427     u16 status;
0428
0429     if (!pnp_bios_present())
0430         return ESCD_FUNCTION_NOT_SUPPORTED;
0431     status = call_pnp_bios(PNP_GET_ESCD_INFO, 0, PNP_TS1, 2, PNP_TS1, 4,
0432                    PNP_TS1, PNP_DS, data,
0433                    sizeof(struct escd_info_struc), NULL, 0);
0434     return status;
0435 }
0436
0437 int pnp_bios_escd_info(struct escd_info_struc *data)
0438 {
0439     int status;
0440
0441     status = __pnp_bios_escd_info(data);
0442     if (status)
0443         pnpbios_print_status("escd_info", status);
0444     return status;
0445 }
0446
0447 /*
0448  * Call PnP BIOS function 0x42, "read ESCD"
0449  * nvram_base is determined by calling escd_info
0450  */
0451 static int __pnp_bios_read_escd(char *data, u32 nvram_base)
0452 {
0453     u16 status;
0454
0455     if (!pnp_bios_present())
0456         return ESCD_FUNCTION_NOT_SUPPORTED;
0457     status = call_pnp_bios(PNP_READ_ESCD, 0, PNP_TS1, PNP_TS2, PNP_DS, 0, 0,
0458                    0, data, 65536, __va(nvram_base), 65536);
0459     return status;
0460 }
0461
0462 int pnp_bios_read_escd(char *data, u32 nvram_base)
0463 {
0464     int status;
0465
0466     status = __pnp_bios_read_escd(data, nvram_base);
0467     if (status)
0468         pnpbios_print_status("read_escd", status);
0469     return status;
0470 }
0471
0472 void pnpbios_calls_init(union pnp_bios_install_struct *header)
0473 {
0474     int i;
0475
0476     pnp_bios_callpoint.offset = header->fields.pm16offset;
0477     pnp_bios_callpoint.segment = PNP_CS16;
0478
0479     for_each_possible_cpu(i) {
0480         struct desc_struct *gdt = get_cpu_gdt_rw(i);
0481         if (!gdt)
0482             continue;
0483         set_desc_base(&gdt[GDT_ENTRY_PNPBIOS_CS32],
0484              (unsigned long)&pnp_bios_callfunc);
0485         set_desc_base(&gdt[GDT_ENTRY_PNPBIOS_CS16],
0486              (unsigned long)__va(header->fields.pm16cseg));
0487         set_desc_base(&gdt[GDT_ENTRY_PNPBIOS_DS],
0488              (unsigned long)__va(header->fields.pm16dseg));
0489     }
0490 }