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 | |
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(lock: &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 | |
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 | */ |
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, arg1: 0, arg2: PNP_TS1, arg3: 2, |
261 | arg4: PNP_TS1, arg5: PNP_DS, arg6: 0, arg7: 0, ts1_base: data, |
262 | ts1_size: sizeof(struct pnp_dev_node_info), NULL, ts2_size: 0); |
263 | data->no_nodes &= 0xff; |
264 | return status; |
265 | } |
266 | |
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(module: "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 | */ |
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, arg1: 0, arg2: PNP_TS1, arg3: 0, arg4: PNP_TS2, |
302 | arg5: boot ? 2 : 1, arg6: PNP_DS, arg7: 0, ts1_base: &tmp_nodenum, |
303 | ts1_size: sizeof(tmp_nodenum), ts2_base: data, ts2_size: 65536); |
304 | *nodenum = tmp_nodenum; |
305 | return status; |
306 | } |
307 | |
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(module: "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 | */ |
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, arg1: nodenum, arg2: 0, arg3: PNP_TS1, |
334 | arg4: boot ? 2 : 1, arg5: PNP_DS, arg6: 0, arg7: 0, ts1_base: data, ts1_size: 65536, NULL, |
335 | ts2_size: 0); |
336 | return status; |
337 | } |
338 | |
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(module: "set_dev_node" , status); |
346 | return status; |
347 | } |
348 | if (!boot) { /* Update devlist */ |
349 | status = pnp_bios_get_dev_node(nodenum: &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 | */ |
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, arg1: 0, arg2: PNP_TS1, |
366 | arg3: PNP_DS, arg4: 0, arg5: 0, arg6: 0, arg7: 0, ts1_base: data, |
367 | ts1_size: sizeof(struct pnp_docking_station_info), NULL, |
368 | ts2_size: 0); |
369 | return status; |
370 | } |
371 | |
372 | /* |
373 | * Call PnP BIOS with function 0x0a, "get statically allocated resource |
374 | * information" |
375 | */ |
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, arg1: 0, arg2: PNP_TS1, |
383 | arg3: PNP_DS, arg4: 0, arg5: 0, arg6: 0, arg7: 0, ts1_base: info, ts1_size: 65536, NULL, ts2_size: 0); |
384 | return status; |
385 | } |
386 | |
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(module: "get_stat_res" , status); |
394 | return status; |
395 | } |
396 | |
397 | /* |
398 | * Call PnP BIOS with function 0x40, "get isa pnp configuration structure" |
399 | */ |
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, arg1: 0, arg2: PNP_TS1, arg3: PNP_DS, |
407 | arg4: 0, arg5: 0, arg6: 0, arg7: 0, ts1_base: data, |
408 | ts1_size: sizeof(struct pnp_isa_config_struc), NULL, ts2_size: 0); |
409 | return status; |
410 | } |
411 | |
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(module: "isapnp_config" , status); |
419 | return status; |
420 | } |
421 | |
422 | /* |
423 | * Call PnP BIOS with function 0x41, "get ESCD info" |
424 | */ |
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, arg1: 0, arg2: PNP_TS1, arg3: 2, arg4: PNP_TS1, arg5: 4, |
432 | arg6: PNP_TS1, arg7: PNP_DS, ts1_base: data, |
433 | ts1_size: sizeof(struct escd_info_struc), NULL, ts2_size: 0); |
434 | return status; |
435 | } |
436 | |
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(module: "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 | */ |
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, arg1: 0, arg2: PNP_TS1, arg3: PNP_TS2, arg4: PNP_DS, arg5: 0, arg6: 0, |
458 | arg7: 0, ts1_base: data, ts1_size: 65536, __va(nvram_base), ts2_size: 65536); |
459 | return status; |
460 | } |
461 | |
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(module: "read_escd" , status); |
469 | return status; |
470 | } |
471 | |
472 | void pnpbios_calls_init(union pnp_bios_install_struct *) |
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(cpu: 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 | |