xref: /openbmc/linux/drivers/pnp/pnpbios/bioscalls.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
1 /*
2  * bioscalls.c - the lowlevel layer of the PnPBIOS driver
3  *
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/pnpbios.h>
12 #include <linux/device.h>
13 #include <linux/pnp.h>
14 #include <linux/mm.h>
15 #include <linux/smp.h>
16 #include <linux/slab.h>
17 #include <linux/kmod.h>
18 #include <linux/completion.h>
19 #include <linux/spinlock.h>
20 
21 #include <asm/page.h>
22 #include <asm/desc.h>
23 #include <asm/system.h>
24 #include <asm/byteorder.h>
25 
26 #include "pnpbios.h"
27 
28 static struct {
29 	u16	offset;
30 	u16	segment;
31 } pnp_bios_callpoint;
32 
33 
34 /* The PnP BIOS entries in the GDT */
35 #define PNP_GDT    (GDT_ENTRY_PNPBIOS_BASE * 8)
36 
37 #define PNP_CS32   (PNP_GDT+0x00)	/* segment for calling fn */
38 #define PNP_CS16   (PNP_GDT+0x08)	/* code segment for BIOS */
39 #define PNP_DS     (PNP_GDT+0x10)	/* data segment for BIOS */
40 #define PNP_TS1    (PNP_GDT+0x18)	/* transfer data segment */
41 #define PNP_TS2    (PNP_GDT+0x20)	/* another data segment */
42 
43 /*
44  * These are some opcodes for a "static asmlinkage"
45  * As this code is *not* executed inside the linux kernel segment, but in a
46  * alias at offset 0, we need a far return that can not be compiled by
47  * default (please, prove me wrong! this is *really* ugly!)
48  * This is the only way to get the bios to return into the kernel code,
49  * because the bios code runs in 16 bit protected mode and therefore can only
50  * return to the caller if the call is within the first 64kB, and the linux
51  * kernel begins at offset 3GB...
52  */
53 
54 asmlinkage void pnp_bios_callfunc(void);
55 
56 __asm__(
57 	".text			\n"
58 	__ALIGN_STR "\n"
59 	"pnp_bios_callfunc:\n"
60 	"	pushl %edx	\n"
61 	"	pushl %ecx	\n"
62 	"	pushl %ebx	\n"
63 	"	pushl %eax	\n"
64 	"	lcallw *pnp_bios_callpoint\n"
65 	"	addl $16, %esp	\n"
66 	"	lret		\n"
67 	".previous		\n"
68 );
69 
70 #define Q_SET_SEL(cpu, selname, address, size) \
71 do { \
72 set_base(per_cpu(cpu_gdt_table,cpu)[(selname) >> 3], __va((u32)(address))); \
73 set_limit(per_cpu(cpu_gdt_table,cpu)[(selname) >> 3], size); \
74 } while(0)
75 
76 #define Q2_SET_SEL(cpu, selname, address, size) \
77 do { \
78 set_base(per_cpu(cpu_gdt_table,cpu)[(selname) >> 3], (u32)(address)); \
79 set_limit(per_cpu(cpu_gdt_table,cpu)[(selname) >> 3], size); \
80 } while(0)
81 
82 static struct desc_struct bad_bios_desc = { 0, 0x00409200 };
83 
84 /*
85  * At some point we want to use this stack frame pointer to unwind
86  * after PnP BIOS oopses.
87  */
88 
89 u32 pnp_bios_fault_esp;
90 u32 pnp_bios_fault_eip;
91 u32 pnp_bios_is_utter_crap = 0;
92 
93 static spinlock_t pnp_bios_lock;
94 
95 
96 /*
97  * Support Functions
98  */
99 
100 static inline u16 call_pnp_bios(u16 func, u16 arg1, u16 arg2, u16 arg3,
101 				u16 arg4, u16 arg5, u16 arg6, u16 arg7,
102 				void *ts1_base, u32 ts1_size,
103 				void *ts2_base, u32 ts2_size)
104 {
105 	unsigned long flags;
106 	u16 status;
107 	struct desc_struct save_desc_40;
108 	int cpu;
109 
110 	/*
111 	 * PnP BIOSes are generally not terribly re-entrant.
112 	 * Also, don't rely on them to save everything correctly.
113 	 */
114 	if(pnp_bios_is_utter_crap)
115 		return PNP_FUNCTION_NOT_SUPPORTED;
116 
117 	cpu = get_cpu();
118 	save_desc_40 = per_cpu(cpu_gdt_table,cpu)[0x40 / 8];
119 	per_cpu(cpu_gdt_table,cpu)[0x40 / 8] = bad_bios_desc;
120 
121 	/* On some boxes IRQ's during PnP BIOS calls are deadly.  */
122 	spin_lock_irqsave(&pnp_bios_lock, flags);
123 
124 	/* The lock prevents us bouncing CPU here */
125 	if (ts1_size)
126 		Q2_SET_SEL(smp_processor_id(), PNP_TS1, ts1_base, ts1_size);
127 	if (ts2_size)
128 		Q2_SET_SEL(smp_processor_id(), PNP_TS2, ts2_base, ts2_size);
129 
130 	__asm__ __volatile__(
131 	        "pushl %%ebp\n\t"
132 		"pushl %%edi\n\t"
133 		"pushl %%esi\n\t"
134 		"pushl %%ds\n\t"
135 		"pushl %%es\n\t"
136 		"pushl %%fs\n\t"
137 		"pushl %%gs\n\t"
138 		"pushfl\n\t"
139 		"movl %%esp, pnp_bios_fault_esp\n\t"
140 		"movl $1f, pnp_bios_fault_eip\n\t"
141 		"lcall %5,%6\n\t"
142 		"1:popfl\n\t"
143 		"popl %%gs\n\t"
144 		"popl %%fs\n\t"
145 		"popl %%es\n\t"
146 		"popl %%ds\n\t"
147 	        "popl %%esi\n\t"
148 		"popl %%edi\n\t"
149 		"popl %%ebp\n\t"
150 		: "=a" (status)
151 		: "0" ((func) | (((u32)arg1) << 16)),
152 		  "b" ((arg2) | (((u32)arg3) << 16)),
153 		  "c" ((arg4) | (((u32)arg5) << 16)),
154 		  "d" ((arg6) | (((u32)arg7) << 16)),
155 		  "i" (PNP_CS32),
156 		  "i" (0)
157 		: "memory"
158 	);
159 	spin_unlock_irqrestore(&pnp_bios_lock, flags);
160 
161 	per_cpu(cpu_gdt_table,cpu)[0x40 / 8] = save_desc_40;
162 	put_cpu();
163 
164 	/* If we get here and this is set then the PnP BIOS faulted on us. */
165 	if(pnp_bios_is_utter_crap)
166 	{
167 		printk(KERN_ERR "PnPBIOS: Warning! Your PnP BIOS caused a fatal error. Attempting to continue\n");
168 		printk(KERN_ERR "PnPBIOS: You may need to reboot with the \"pnpbios=off\" option to operate stably\n");
169 		printk(KERN_ERR "PnPBIOS: Check with your vendor for an updated BIOS\n");
170 	}
171 
172 	return status;
173 }
174 
175 void pnpbios_print_status(const char * module, u16 status)
176 {
177 	switch(status) {
178 	case PNP_SUCCESS:
179 		printk(KERN_ERR "PnPBIOS: %s: function successful\n", module);
180 		break;
181 	case PNP_NOT_SET_STATICALLY:
182 		printk(KERN_ERR "PnPBIOS: %s: unable to set static resources\n", module);
183 		break;
184 	case PNP_UNKNOWN_FUNCTION:
185 		printk(KERN_ERR "PnPBIOS: %s: invalid function number passed\n", module);
186 		break;
187 	case PNP_FUNCTION_NOT_SUPPORTED:
188 		printk(KERN_ERR "PnPBIOS: %s: function not supported on this system\n", module);
189 		break;
190 	case PNP_INVALID_HANDLE:
191 		printk(KERN_ERR "PnPBIOS: %s: invalid handle\n", module);
192 		break;
193 	case PNP_BAD_PARAMETER:
194 		printk(KERN_ERR "PnPBIOS: %s: invalid parameters were passed\n", module);
195 		break;
196 	case PNP_SET_FAILED:
197 		printk(KERN_ERR "PnPBIOS: %s: unable to set resources\n", module);
198 		break;
199 	case PNP_EVENTS_NOT_PENDING:
200 		printk(KERN_ERR "PnPBIOS: %s: no events are pending\n", module);
201 		break;
202 	case PNP_SYSTEM_NOT_DOCKED:
203 		printk(KERN_ERR "PnPBIOS: %s: the system is not docked\n", module);
204 		break;
205 	case PNP_NO_ISA_PNP_CARDS:
206 		printk(KERN_ERR "PnPBIOS: %s: no isapnp cards are installed on this system\n", module);
207 		break;
208 	case PNP_UNABLE_TO_DETERMINE_DOCK_CAPABILITIES:
209 		printk(KERN_ERR "PnPBIOS: %s: cannot determine the capabilities of the docking station\n", module);
210 		break;
211 	case PNP_CONFIG_CHANGE_FAILED_NO_BATTERY:
212 		printk(KERN_ERR "PnPBIOS: %s: unable to undock, the system does not have a battery\n", module);
213 		break;
214 	case PNP_CONFIG_CHANGE_FAILED_RESOURCE_CONFLICT:
215 		printk(KERN_ERR "PnPBIOS: %s: could not dock due to resource conflicts\n", module);
216 		break;
217 	case PNP_BUFFER_TOO_SMALL:
218 		printk(KERN_ERR "PnPBIOS: %s: the buffer passed is too small\n", module);
219 		break;
220 	case PNP_USE_ESCD_SUPPORT:
221 		printk(KERN_ERR "PnPBIOS: %s: use ESCD instead\n", module);
222 		break;
223 	case PNP_MESSAGE_NOT_SUPPORTED:
224 		printk(KERN_ERR "PnPBIOS: %s: the message is unsupported\n", module);
225 		break;
226 	case PNP_HARDWARE_ERROR:
227 		printk(KERN_ERR "PnPBIOS: %s: a hardware failure has occured\n", module);
228 		break;
229 	default:
230 		printk(KERN_ERR "PnPBIOS: %s: unexpected status 0x%x\n", module, status);
231 		break;
232 	}
233 }
234 
235 
236 /*
237  * PnP BIOS Low Level Calls
238  */
239 
240 #define PNP_GET_NUM_SYS_DEV_NODES		0x00
241 #define PNP_GET_SYS_DEV_NODE			0x01
242 #define PNP_SET_SYS_DEV_NODE			0x02
243 #define PNP_GET_EVENT				0x03
244 #define PNP_SEND_MESSAGE			0x04
245 #define PNP_GET_DOCKING_STATION_INFORMATION	0x05
246 #define PNP_SET_STATIC_ALLOCED_RES_INFO		0x09
247 #define PNP_GET_STATIC_ALLOCED_RES_INFO		0x0a
248 #define PNP_GET_APM_ID_TABLE			0x0b
249 #define PNP_GET_PNP_ISA_CONFIG_STRUC		0x40
250 #define PNP_GET_ESCD_INFO			0x41
251 #define PNP_READ_ESCD				0x42
252 #define PNP_WRITE_ESCD				0x43
253 
254 /*
255  * Call PnP BIOS with function 0x00, "get number of system device nodes"
256  */
257 static int __pnp_bios_dev_node_info(struct pnp_dev_node_info *data)
258 {
259 	u16 status;
260 	if (!pnp_bios_present())
261 		return PNP_FUNCTION_NOT_SUPPORTED;
262 	status = call_pnp_bios(PNP_GET_NUM_SYS_DEV_NODES, 0, PNP_TS1, 2, PNP_TS1, PNP_DS, 0, 0,
263 			       data, sizeof(struct pnp_dev_node_info), NULL, 0);
264 	data->no_nodes &= 0xff;
265 	return status;
266 }
267 
268 int pnp_bios_dev_node_info(struct pnp_dev_node_info *data)
269 {
270 	int status = __pnp_bios_dev_node_info( data );
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  */
290 static int __pnp_bios_get_dev_node(u8 *nodenum, char boot, struct pnp_bios_node *data)
291 {
292 	u16 status;
293 	if (!pnp_bios_present())
294 		return PNP_FUNCTION_NOT_SUPPORTED;
295 	if ( !boot && pnpbios_dont_use_current_config )
296 		return PNP_FUNCTION_NOT_SUPPORTED;
297 	status = call_pnp_bios(PNP_GET_SYS_DEV_NODE, 0, PNP_TS1, 0, PNP_TS2, boot ? 2 : 1, PNP_DS, 0,
298 			       nodenum, sizeof(char), data, 65536);
299 	return status;
300 }
301 
302 int pnp_bios_get_dev_node(u8 *nodenum, char boot, struct pnp_bios_node *data)
303 {
304 	int status;
305 	status =  __pnp_bios_get_dev_node( nodenum, boot, data );
306 	if ( status )
307 		pnpbios_print_status( "get_dev_node", status );
308 	return status;
309 }
310 
311 
312 /*
313  * Call PnP BIOS with function 0x02, "set system device node"
314  * Input: *nodenum = desired node,
315  *        boot = whether to set nonvolatile boot (!=0)
316  *               or volatile current (0) config
317  */
318 static int __pnp_bios_set_dev_node(u8 nodenum, char boot, struct pnp_bios_node *data)
319 {
320 	u16 status;
321 	if (!pnp_bios_present())
322 		return PNP_FUNCTION_NOT_SUPPORTED;
323 	if ( !boot && pnpbios_dont_use_current_config )
324 		return PNP_FUNCTION_NOT_SUPPORTED;
325 	status = call_pnp_bios(PNP_SET_SYS_DEV_NODE, nodenum, 0, PNP_TS1, boot ? 2 : 1, PNP_DS, 0, 0,
326 			       data, 65536, NULL, 0);
327 	return status;
328 }
329 
330 int pnp_bios_set_dev_node(u8 nodenum, char boot, struct pnp_bios_node *data)
331 {
332 	int status;
333 	status =  __pnp_bios_set_dev_node( nodenum, boot, data );
334 	if ( status ) {
335 		pnpbios_print_status( "set_dev_node", status );
336 		return status;
337 	}
338 	if ( !boot ) { /* Update devlist */
339 		status =  pnp_bios_get_dev_node( &nodenum, boot, data );
340 		if ( status )
341 			return status;
342 	}
343 	return status;
344 }
345 
346 #if needed
347 /*
348  * Call PnP BIOS with function 0x03, "get event"
349  */
350 static int pnp_bios_get_event(u16 *event)
351 {
352 	u16 status;
353 	if (!pnp_bios_present())
354 		return PNP_FUNCTION_NOT_SUPPORTED;
355 	status = call_pnp_bios(PNP_GET_EVENT, 0, PNP_TS1, PNP_DS, 0, 0 ,0 ,0,
356 			       event, sizeof(u16), NULL, 0);
357 	return status;
358 }
359 #endif
360 
361 #if needed
362 /*
363  * Call PnP BIOS with function 0x04, "send message"
364  */
365 static int pnp_bios_send_message(u16 message)
366 {
367 	u16 status;
368 	if (!pnp_bios_present())
369 		return PNP_FUNCTION_NOT_SUPPORTED;
370 	status = call_pnp_bios(PNP_SEND_MESSAGE, message, PNP_DS, 0, 0, 0, 0, 0, 0, 0, 0, 0);
371 	return status;
372 }
373 #endif
374 
375 /*
376  * Call PnP BIOS with function 0x05, "get docking station information"
377  */
378 int pnp_bios_dock_station_info(struct pnp_docking_station_info *data)
379 {
380 	u16 status;
381 	if (!pnp_bios_present())
382 		return PNP_FUNCTION_NOT_SUPPORTED;
383 	status = call_pnp_bios(PNP_GET_DOCKING_STATION_INFORMATION, 0, PNP_TS1, PNP_DS, 0, 0, 0, 0,
384 			       data, sizeof(struct pnp_docking_station_info), NULL, 0);
385 	return status;
386 }
387 
388 #if needed
389 /*
390  * Call PnP BIOS with function 0x09, "set statically allocated resource
391  * information"
392  */
393 static int pnp_bios_set_stat_res(char *info)
394 {
395 	u16 status;
396 	if (!pnp_bios_present())
397 		return PNP_FUNCTION_NOT_SUPPORTED;
398 	status = call_pnp_bios(PNP_SET_STATIC_ALLOCED_RES_INFO, 0, PNP_TS1, PNP_DS, 0, 0, 0, 0,
399 			       info, *((u16 *) info), 0, 0);
400 	return status;
401 }
402 #endif
403 
404 /*
405  * Call PnP BIOS with function 0x0a, "get statically allocated resource
406  * information"
407  */
408 static int __pnp_bios_get_stat_res(char *info)
409 {
410 	u16 status;
411 	if (!pnp_bios_present())
412 		return PNP_FUNCTION_NOT_SUPPORTED;
413 	status = call_pnp_bios(PNP_GET_STATIC_ALLOCED_RES_INFO, 0, PNP_TS1, PNP_DS, 0, 0, 0, 0,
414 			       info, 65536, NULL, 0);
415 	return status;
416 }
417 
418 int pnp_bios_get_stat_res(char *info)
419 {
420 	int status;
421 	status = __pnp_bios_get_stat_res( info );
422 	if ( status )
423 		pnpbios_print_status( "get_stat_res", status );
424 	return status;
425 }
426 
427 #if needed
428 /*
429  * Call PnP BIOS with function 0x0b, "get APM id table"
430  */
431 static int pnp_bios_apm_id_table(char *table, u16 *size)
432 {
433 	u16 status;
434 	if (!pnp_bios_present())
435 		return PNP_FUNCTION_NOT_SUPPORTED;
436 	status = call_pnp_bios(PNP_GET_APM_ID_TABLE, 0, PNP_TS2, 0, PNP_TS1, PNP_DS, 0, 0,
437 			       table, *size, size, sizeof(u16));
438 	return status;
439 }
440 #endif
441 
442 /*
443  * Call PnP BIOS with function 0x40, "get isa pnp configuration structure"
444  */
445 static int __pnp_bios_isapnp_config(struct pnp_isa_config_struc *data)
446 {
447 	u16 status;
448 	if (!pnp_bios_present())
449 		return PNP_FUNCTION_NOT_SUPPORTED;
450 	status = call_pnp_bios(PNP_GET_PNP_ISA_CONFIG_STRUC, 0, PNP_TS1, PNP_DS, 0, 0, 0, 0,
451 			       data, sizeof(struct pnp_isa_config_struc), NULL, 0);
452 	return status;
453 }
454 
455 int pnp_bios_isapnp_config(struct pnp_isa_config_struc *data)
456 {
457 	int status;
458 	status = __pnp_bios_isapnp_config( data );
459 	if ( status )
460 		pnpbios_print_status( "isapnp_config", status );
461 	return status;
462 }
463 
464 /*
465  * Call PnP BIOS with function 0x41, "get ESCD info"
466  */
467 static int __pnp_bios_escd_info(struct escd_info_struc *data)
468 {
469 	u16 status;
470 	if (!pnp_bios_present())
471 		return ESCD_FUNCTION_NOT_SUPPORTED;
472 	status = call_pnp_bios(PNP_GET_ESCD_INFO, 0, PNP_TS1, 2, PNP_TS1, 4, PNP_TS1, PNP_DS,
473 			       data, sizeof(struct escd_info_struc), NULL, 0);
474 	return status;
475 }
476 
477 int pnp_bios_escd_info(struct escd_info_struc *data)
478 {
479 	int status;
480 	status = __pnp_bios_escd_info( data );
481 	if ( status )
482 		pnpbios_print_status( "escd_info", status );
483 	return status;
484 }
485 
486 /*
487  * Call PnP BIOS function 0x42, "read ESCD"
488  * nvram_base is determined by calling escd_info
489  */
490 static int __pnp_bios_read_escd(char *data, u32 nvram_base)
491 {
492 	u16 status;
493 	if (!pnp_bios_present())
494 		return ESCD_FUNCTION_NOT_SUPPORTED;
495 	status = call_pnp_bios(PNP_READ_ESCD, 0, PNP_TS1, PNP_TS2, PNP_DS, 0, 0, 0,
496 			       data, 65536, __va(nvram_base), 65536);
497 	return status;
498 }
499 
500 int pnp_bios_read_escd(char *data, u32 nvram_base)
501 {
502 	int status;
503 	status = __pnp_bios_read_escd( data, nvram_base );
504 	if ( status )
505 		pnpbios_print_status( "read_escd", status );
506 	return status;
507 }
508 
509 #if needed
510 /*
511  * Call PnP BIOS function 0x43, "write ESCD"
512  */
513 static int pnp_bios_write_escd(char *data, u32 nvram_base)
514 {
515 	u16 status;
516 	if (!pnp_bios_present())
517 		return ESCD_FUNCTION_NOT_SUPPORTED;
518 	status = call_pnp_bios(PNP_WRITE_ESCD, 0, PNP_TS1, PNP_TS2, PNP_DS, 0, 0, 0,
519 			       data, 65536, __va(nvram_base), 65536);
520 	return status;
521 }
522 #endif
523 
524 
525 /*
526  * Initialization
527  */
528 
529 void pnpbios_calls_init(union pnp_bios_install_struct *header)
530 {
531 	int i;
532 	spin_lock_init(&pnp_bios_lock);
533 	pnp_bios_callpoint.offset = header->fields.pm16offset;
534 	pnp_bios_callpoint.segment = PNP_CS16;
535 
536 	set_base(bad_bios_desc, __va((unsigned long)0x40 << 4));
537 	_set_limit((char *)&bad_bios_desc, 4095 - (0x40 << 4));
538 	for(i=0; i < NR_CPUS; i++)
539 	{
540 		Q2_SET_SEL(i, PNP_CS32, &pnp_bios_callfunc, 64 * 1024);
541 		Q_SET_SEL(i, PNP_CS16, header->fields.pm16cseg, 64 * 1024);
542 		Q_SET_SEL(i, PNP_DS, header->fields.pm16dseg, 64 * 1024);
543 	}
544 }
545