xref: /openbmc/linux/drivers/pnp/pnpbios/bioscalls.c (revision 12eb4683)
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 }
490