1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * bioscalls.c - the lowlevel layer of the PnPBIOS driver
4 */
5
6 #include <linux/types.h>
7 #include <linux/module.h>
8 #include <linux/init.h>
9 #include <linux/linkage.h>
10 #include <linux/kernel.h>
11 #include <linux/device.h>
12 #include <linux/pnp.h>
13 #include <linux/mm.h>
14 #include <linux/smp.h>
15 #include <linux/kmod.h>
16 #include <linux/completion.h>
17 #include <linux/spinlock.h>
18
19 #include <asm/page.h>
20 #include <asm/desc.h>
21 #include <asm/byteorder.h>
22
23 #include "pnpbios.h"
24
25 __visible struct {
26 u16 offset;
27 u16 segment;
28 } pnp_bios_callpoint;
29
30 /*
31 * These are some opcodes for a "static asmlinkage"
32 * As this code is *not* executed inside the linux kernel segment, but in a
33 * alias at offset 0, we need a far return that can not be compiled by
34 * default (please, prove me wrong! this is *really* ugly!)
35 * This is the only way to get the bios to return into the kernel code,
36 * because the bios code runs in 16 bit protected mode and therefore can only
37 * return to the caller if the call is within the first 64kB, and the linux
38 * kernel begins at offset 3GB...
39 */
40
41 asmlinkage __visible void pnp_bios_callfunc(void);
42
43 __asm__(".text \n"
44 __ALIGN_STR "\n"
45 ".globl pnp_bios_callfunc\n"
46 "pnp_bios_callfunc:\n"
47 " pushl %edx \n"
48 " pushl %ecx \n"
49 " pushl %ebx \n"
50 " pushl %eax \n"
51 " lcallw *pnp_bios_callpoint\n"
52 " addl $16, %esp \n"
53 " lret \n"
54 ".previous \n");
55
56 #define Q2_SET_SEL(cpu, selname, address, size) \
57 do { \
58 struct desc_struct *gdt = get_cpu_gdt_rw((cpu)); \
59 set_desc_base(&gdt[(selname) >> 3], (u32)(address)); \
60 set_desc_limit(&gdt[(selname) >> 3], (size) - 1); \
61 } while(0)
62
63 static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
64 (unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
65
66 /*
67 * At some point we want to use this stack frame pointer to unwind
68 * after PnP BIOS oopses.
69 */
70
71 __visible u32 pnp_bios_fault_esp;
72 __visible u32 pnp_bios_fault_eip;
73 __visible u32 pnp_bios_is_utter_crap = 0;
74
75 static DEFINE_SPINLOCK(pnp_bios_lock);
76
77 /*
78 * Support Functions
79 */
80
call_pnp_bios(u16 func,u16 arg1,u16 arg2,u16 arg3,u16 arg4,u16 arg5,u16 arg6,u16 arg7,void * ts1_base,u32 ts1_size,void * ts2_base,u32 ts2_size)81 static inline u16 call_pnp_bios(u16 func, u16 arg1, u16 arg2, u16 arg3,
82 u16 arg4, u16 arg5, u16 arg6, u16 arg7,
83 void *ts1_base, u32 ts1_size,
84 void *ts2_base, u32 ts2_size)
85 {
86 unsigned long flags;
87 u16 status;
88 struct desc_struct save_desc_40;
89 int cpu;
90
91 /*
92 * PnP BIOSes are generally not terribly re-entrant.
93 * Also, don't rely on them to save everything correctly.
94 */
95 if (pnp_bios_is_utter_crap)
96 return PNP_FUNCTION_NOT_SUPPORTED;
97
98 cpu = get_cpu();
99 save_desc_40 = get_cpu_gdt_rw(cpu)[0x40 / 8];
100 get_cpu_gdt_rw(cpu)[0x40 / 8] = bad_bios_desc;
101
102 /* On some boxes IRQ's during PnP BIOS calls are deadly. */
103 spin_lock_irqsave(&pnp_bios_lock, flags);
104
105 /* The lock prevents us bouncing CPU here */
106 if (ts1_size)
107 Q2_SET_SEL(smp_processor_id(), PNP_TS1, ts1_base, ts1_size);
108 if (ts2_size)
109 Q2_SET_SEL(smp_processor_id(), PNP_TS2, ts2_base, ts2_size);
110
111 __asm__ __volatile__("pushl %%ebp\n\t"
112 "pushl %%edi\n\t"
113 "pushl %%esi\n\t"
114 "pushl %%ds\n\t"
115 "pushl %%es\n\t"
116 "pushl %%fs\n\t"
117 "pushl %%gs\n\t"
118 "pushfl\n\t"
119 "movl %%esp, pnp_bios_fault_esp\n\t"
120 "movl $1f, pnp_bios_fault_eip\n\t"
121 "lcall %5,%6\n\t"
122 "1:popfl\n\t"
123 "popl %%gs\n\t"
124 "popl %%fs\n\t"
125 "popl %%es\n\t"
126 "popl %%ds\n\t"
127 "popl %%esi\n\t"
128 "popl %%edi\n\t"
129 "popl %%ebp\n\t":"=a"(status)
130 :"0"((func) | (((u32) arg1) << 16)),
131 "b"((arg2) | (((u32) arg3) << 16)),
132 "c"((arg4) | (((u32) arg5) << 16)),
133 "d"((arg6) | (((u32) arg7) << 16)),
134 "i"(PNP_CS32), "i"(0)
135 :"memory");
136 spin_unlock_irqrestore(&pnp_bios_lock, flags);
137
138 get_cpu_gdt_rw(cpu)[0x40 / 8] = save_desc_40;
139 put_cpu();
140
141 /* If we get here and this is set then the PnP BIOS faulted on us. */
142 if (pnp_bios_is_utter_crap) {
143 printk(KERN_ERR
144 "PnPBIOS: Warning! Your PnP BIOS caused a fatal error. Attempting to continue\n");
145 printk(KERN_ERR
146 "PnPBIOS: You may need to reboot with the \"pnpbios=off\" option to operate stably\n");
147 printk(KERN_ERR
148 "PnPBIOS: Check with your vendor for an updated BIOS\n");
149 }
150
151 return status;
152 }
153
pnpbios_print_status(const char * module,u16 status)154 void pnpbios_print_status(const char *module, u16 status)
155 {
156 switch (status) {
157 case PNP_SUCCESS:
158 printk(KERN_ERR "PnPBIOS: %s: function successful\n", module);
159 break;
160 case PNP_NOT_SET_STATICALLY:
161 printk(KERN_ERR "PnPBIOS: %s: unable to set static resources\n",
162 module);
163 break;
164 case PNP_UNKNOWN_FUNCTION:
165 printk(KERN_ERR "PnPBIOS: %s: invalid function number passed\n",
166 module);
167 break;
168 case PNP_FUNCTION_NOT_SUPPORTED:
169 printk(KERN_ERR
170 "PnPBIOS: %s: function not supported on this system\n",
171 module);
172 break;
173 case PNP_INVALID_HANDLE:
174 printk(KERN_ERR "PnPBIOS: %s: invalid handle\n", module);
175 break;
176 case PNP_BAD_PARAMETER:
177 printk(KERN_ERR "PnPBIOS: %s: invalid parameters were passed\n",
178 module);
179 break;
180 case PNP_SET_FAILED:
181 printk(KERN_ERR "PnPBIOS: %s: unable to set resources\n",
182 module);
183 break;
184 case PNP_EVENTS_NOT_PENDING:
185 printk(KERN_ERR "PnPBIOS: %s: no events are pending\n", module);
186 break;
187 case PNP_SYSTEM_NOT_DOCKED:
188 printk(KERN_ERR "PnPBIOS: %s: the system is not docked\n",
189 module);
190 break;
191 case PNP_NO_ISA_PNP_CARDS:
192 printk(KERN_ERR
193 "PnPBIOS: %s: no isapnp cards are installed on this system\n",
194 module);
195 break;
196 case PNP_UNABLE_TO_DETERMINE_DOCK_CAPABILITIES:
197 printk(KERN_ERR
198 "PnPBIOS: %s: cannot determine the capabilities of the docking station\n",
199 module);
200 break;
201 case PNP_CONFIG_CHANGE_FAILED_NO_BATTERY:
202 printk(KERN_ERR
203 "PnPBIOS: %s: unable to undock, the system does not have a battery\n",
204 module);
205 break;
206 case PNP_CONFIG_CHANGE_FAILED_RESOURCE_CONFLICT:
207 printk(KERN_ERR
208 "PnPBIOS: %s: could not dock due to resource conflicts\n",
209 module);
210 break;
211 case PNP_BUFFER_TOO_SMALL:
212 printk(KERN_ERR "PnPBIOS: %s: the buffer passed is too small\n",
213 module);
214 break;
215 case PNP_USE_ESCD_SUPPORT:
216 printk(KERN_ERR "PnPBIOS: %s: use ESCD instead\n", module);
217 break;
218 case PNP_MESSAGE_NOT_SUPPORTED:
219 printk(KERN_ERR "PnPBIOS: %s: the message is unsupported\n",
220 module);
221 break;
222 case PNP_HARDWARE_ERROR:
223 printk(KERN_ERR "PnPBIOS: %s: a hardware failure has occurred\n",
224 module);
225 break;
226 default:
227 printk(KERN_ERR "PnPBIOS: %s: unexpected status 0x%x\n", module,
228 status);
229 break;
230 }
231 }
232
233 /*
234 * PnP BIOS Low Level Calls
235 */
236
237 #define PNP_GET_NUM_SYS_DEV_NODES 0x00
238 #define PNP_GET_SYS_DEV_NODE 0x01
239 #define PNP_SET_SYS_DEV_NODE 0x02
240 #define PNP_GET_EVENT 0x03
241 #define PNP_SEND_MESSAGE 0x04
242 #define PNP_GET_DOCKING_STATION_INFORMATION 0x05
243 #define PNP_SET_STATIC_ALLOCED_RES_INFO 0x09
244 #define PNP_GET_STATIC_ALLOCED_RES_INFO 0x0a
245 #define PNP_GET_APM_ID_TABLE 0x0b
246 #define PNP_GET_PNP_ISA_CONFIG_STRUC 0x40
247 #define PNP_GET_ESCD_INFO 0x41
248 #define PNP_READ_ESCD 0x42
249 #define PNP_WRITE_ESCD 0x43
250
251 /*
252 * Call PnP BIOS with function 0x00, "get number of system device nodes"
253 */
__pnp_bios_dev_node_info(struct pnp_dev_node_info * data)254 static int __pnp_bios_dev_node_info(struct pnp_dev_node_info *data)
255 {
256 u16 status;
257
258 if (!pnp_bios_present())
259 return PNP_FUNCTION_NOT_SUPPORTED;
260 status = call_pnp_bios(PNP_GET_NUM_SYS_DEV_NODES, 0, PNP_TS1, 2,
261 PNP_TS1, PNP_DS, 0, 0, data,
262 sizeof(struct pnp_dev_node_info), NULL, 0);
263 data->no_nodes &= 0xff;
264 return status;
265 }
266
pnp_bios_dev_node_info(struct pnp_dev_node_info * data)267 int pnp_bios_dev_node_info(struct pnp_dev_node_info *data)
268 {
269 int status = __pnp_bios_dev_node_info(data);
270
271 if (status)
272 pnpbios_print_status("dev_node_info", status);
273 return status;
274 }
275
276 /*
277 * Note that some PnP BIOSes (e.g., on Sony Vaio laptops) die a horrible
278 * death if they are asked to access the "current" configuration.
279 * Therefore, if it's a matter of indifference, it's better to call
280 * get_dev_node() and set_dev_node() with boot=1 rather than with boot=0.
281 */
282
283 /*
284 * Call PnP BIOS with function 0x01, "get system device node"
285 * Input: *nodenum = desired node,
286 * boot = whether to get nonvolatile boot (!=0)
287 * or volatile current (0) config
288 * Output: *nodenum=next node or 0xff if no more nodes
289 */
__pnp_bios_get_dev_node(u8 * nodenum,char boot,struct pnp_bios_node * data)290 static int __pnp_bios_get_dev_node(u8 *nodenum, char boot,
291 struct pnp_bios_node *data)
292 {
293 u16 status;
294 u16 tmp_nodenum;
295
296 if (!pnp_bios_present())
297 return PNP_FUNCTION_NOT_SUPPORTED;
298 if (!boot && pnpbios_dont_use_current_config)
299 return PNP_FUNCTION_NOT_SUPPORTED;
300 tmp_nodenum = *nodenum;
301 status = call_pnp_bios(PNP_GET_SYS_DEV_NODE, 0, PNP_TS1, 0, PNP_TS2,
302 boot ? 2 : 1, PNP_DS, 0, &tmp_nodenum,
303 sizeof(tmp_nodenum), data, 65536);
304 *nodenum = tmp_nodenum;
305 return status;
306 }
307
pnp_bios_get_dev_node(u8 * nodenum,char boot,struct pnp_bios_node * data)308 int pnp_bios_get_dev_node(u8 *nodenum, char boot, struct pnp_bios_node *data)
309 {
310 int status;
311
312 status = __pnp_bios_get_dev_node(nodenum, boot, data);
313 if (status)
314 pnpbios_print_status("get_dev_node", status);
315 return status;
316 }
317
318 /*
319 * Call PnP BIOS with function 0x02, "set system device node"
320 * Input: *nodenum = desired node,
321 * boot = whether to set nonvolatile boot (!=0)
322 * or volatile current (0) config
323 */
__pnp_bios_set_dev_node(u8 nodenum,char boot,struct pnp_bios_node * data)324 static int __pnp_bios_set_dev_node(u8 nodenum, char boot,
325 struct pnp_bios_node *data)
326 {
327 u16 status;
328
329 if (!pnp_bios_present())
330 return PNP_FUNCTION_NOT_SUPPORTED;
331 if (!boot && pnpbios_dont_use_current_config)
332 return PNP_FUNCTION_NOT_SUPPORTED;
333 status = call_pnp_bios(PNP_SET_SYS_DEV_NODE, nodenum, 0, PNP_TS1,
334 boot ? 2 : 1, PNP_DS, 0, 0, data, 65536, NULL,
335 0);
336 return status;
337 }
338
pnp_bios_set_dev_node(u8 nodenum,char boot,struct pnp_bios_node * data)339 int pnp_bios_set_dev_node(u8 nodenum, char boot, struct pnp_bios_node *data)
340 {
341 int status;
342
343 status = __pnp_bios_set_dev_node(nodenum, boot, data);
344 if (status) {
345 pnpbios_print_status("set_dev_node", status);
346 return status;
347 }
348 if (!boot) { /* Update devlist */
349 status = pnp_bios_get_dev_node(&nodenum, boot, data);
350 if (status)
351 return status;
352 }
353 return status;
354 }
355
356 /*
357 * Call PnP BIOS with function 0x05, "get docking station information"
358 */
pnp_bios_dock_station_info(struct pnp_docking_station_info * data)359 int pnp_bios_dock_station_info(struct pnp_docking_station_info *data)
360 {
361 u16 status;
362
363 if (!pnp_bios_present())
364 return PNP_FUNCTION_NOT_SUPPORTED;
365 status = call_pnp_bios(PNP_GET_DOCKING_STATION_INFORMATION, 0, PNP_TS1,
366 PNP_DS, 0, 0, 0, 0, data,
367 sizeof(struct pnp_docking_station_info), NULL,
368 0);
369 return status;
370 }
371
372 /*
373 * Call PnP BIOS with function 0x0a, "get statically allocated resource
374 * information"
375 */
__pnp_bios_get_stat_res(char * info)376 static int __pnp_bios_get_stat_res(char *info)
377 {
378 u16 status;
379
380 if (!pnp_bios_present())
381 return PNP_FUNCTION_NOT_SUPPORTED;
382 status = call_pnp_bios(PNP_GET_STATIC_ALLOCED_RES_INFO, 0, PNP_TS1,
383 PNP_DS, 0, 0, 0, 0, info, 65536, NULL, 0);
384 return status;
385 }
386
pnp_bios_get_stat_res(char * info)387 int pnp_bios_get_stat_res(char *info)
388 {
389 int status;
390
391 status = __pnp_bios_get_stat_res(info);
392 if (status)
393 pnpbios_print_status("get_stat_res", status);
394 return status;
395 }
396
397 /*
398 * Call PnP BIOS with function 0x40, "get isa pnp configuration structure"
399 */
__pnp_bios_isapnp_config(struct pnp_isa_config_struc * data)400 static int __pnp_bios_isapnp_config(struct pnp_isa_config_struc *data)
401 {
402 u16 status;
403
404 if (!pnp_bios_present())
405 return PNP_FUNCTION_NOT_SUPPORTED;
406 status = call_pnp_bios(PNP_GET_PNP_ISA_CONFIG_STRUC, 0, PNP_TS1, PNP_DS,
407 0, 0, 0, 0, data,
408 sizeof(struct pnp_isa_config_struc), NULL, 0);
409 return status;
410 }
411
pnp_bios_isapnp_config(struct pnp_isa_config_struc * data)412 int pnp_bios_isapnp_config(struct pnp_isa_config_struc *data)
413 {
414 int status;
415
416 status = __pnp_bios_isapnp_config(data);
417 if (status)
418 pnpbios_print_status("isapnp_config", status);
419 return status;
420 }
421
422 /*
423 * Call PnP BIOS with function 0x41, "get ESCD info"
424 */
__pnp_bios_escd_info(struct escd_info_struc * data)425 static int __pnp_bios_escd_info(struct escd_info_struc *data)
426 {
427 u16 status;
428
429 if (!pnp_bios_present())
430 return ESCD_FUNCTION_NOT_SUPPORTED;
431 status = call_pnp_bios(PNP_GET_ESCD_INFO, 0, PNP_TS1, 2, PNP_TS1, 4,
432 PNP_TS1, PNP_DS, data,
433 sizeof(struct escd_info_struc), NULL, 0);
434 return status;
435 }
436
pnp_bios_escd_info(struct escd_info_struc * data)437 int pnp_bios_escd_info(struct escd_info_struc *data)
438 {
439 int status;
440
441 status = __pnp_bios_escd_info(data);
442 if (status)
443 pnpbios_print_status("escd_info", status);
444 return status;
445 }
446
447 /*
448 * Call PnP BIOS function 0x42, "read ESCD"
449 * nvram_base is determined by calling escd_info
450 */
__pnp_bios_read_escd(char * data,u32 nvram_base)451 static int __pnp_bios_read_escd(char *data, u32 nvram_base)
452 {
453 u16 status;
454
455 if (!pnp_bios_present())
456 return ESCD_FUNCTION_NOT_SUPPORTED;
457 status = call_pnp_bios(PNP_READ_ESCD, 0, PNP_TS1, PNP_TS2, PNP_DS, 0, 0,
458 0, data, 65536, __va(nvram_base), 65536);
459 return status;
460 }
461
pnp_bios_read_escd(char * data,u32 nvram_base)462 int pnp_bios_read_escd(char *data, u32 nvram_base)
463 {
464 int status;
465
466 status = __pnp_bios_read_escd(data, nvram_base);
467 if (status)
468 pnpbios_print_status("read_escd", status);
469 return status;
470 }
471
pnpbios_calls_init(union pnp_bios_install_struct * header)472 void pnpbios_calls_init(union pnp_bios_install_struct *header)
473 {
474 int i;
475
476 pnp_bios_callpoint.offset = header->fields.pm16offset;
477 pnp_bios_callpoint.segment = PNP_CS16;
478
479 for_each_possible_cpu(i) {
480 struct desc_struct *gdt = get_cpu_gdt_rw(i);
481 if (!gdt)
482 continue;
483 set_desc_base(&gdt[GDT_ENTRY_PNPBIOS_CS32],
484 (unsigned long)&pnp_bios_callfunc);
485 set_desc_base(&gdt[GDT_ENTRY_PNPBIOS_CS16],
486 (unsigned long)__va(header->fields.pm16cseg));
487 set_desc_base(&gdt[GDT_ENTRY_PNPBIOS_DS],
488 (unsigned long)__va(header->fields.pm16dseg));
489 }
490 }
491