xref: /openbmc/linux/drivers/pnp/pnpbios/bioscalls.c (revision afb46f79)
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 __visible 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 	".globl pnp_bios_callfunc\n"
45 	"pnp_bios_callfunc:\n"
46 	"	pushl %edx	\n"
47 	"	pushl %ecx	\n"
48 	"	pushl %ebx	\n"
49 	"	pushl %eax	\n"
50 	"	lcallw *pnp_bios_callpoint\n"
51 	"	addl $16, %esp	\n"
52 	"	lret		\n"
53 	".previous		\n");
54 
55 #define Q2_SET_SEL(cpu, selname, address, size) \
56 do { \
57 	struct desc_struct *gdt = get_cpu_gdt_table((cpu)); \
58 	set_desc_base(&gdt[(selname) >> 3], (u32)(address)); \
59 	set_desc_limit(&gdt[(selname) >> 3], (size) - 1); \
60 } while(0)
61 
62 static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
63 			(unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
64 
65 /*
66  * At some point we want to use this stack frame pointer to unwind
67  * after PnP BIOS oopses.
68  */
69 
70 __visible u32 pnp_bios_fault_esp;
71 __visible u32 pnp_bios_fault_eip;
72 __visible u32 pnp_bios_is_utter_crap = 0;
73 
74 static spinlock_t pnp_bios_lock;
75 
76 /*
77  * Support Functions
78  */
79 
80 static inline u16 call_pnp_bios(u16 func, u16 arg1, u16 arg2, u16 arg3,
81 				u16 arg4, u16 arg5, u16 arg6, u16 arg7,
82 				void *ts1_base, u32 ts1_size,
83 				void *ts2_base, u32 ts2_size)
84 {
85 	unsigned long flags;
86 	u16 status;
87 	struct desc_struct save_desc_40;
88 	int cpu;
89 
90 	/*
91 	 * PnP BIOSes are generally not terribly re-entrant.
92 	 * Also, don't rely on them to save everything correctly.
93 	 */
94 	if (pnp_bios_is_utter_crap)
95 		return PNP_FUNCTION_NOT_SUPPORTED;
96 
97 	cpu = get_cpu();
98 	save_desc_40 = get_cpu_gdt_table(cpu)[0x40 / 8];
99 	get_cpu_gdt_table(cpu)[0x40 / 8] = bad_bios_desc;
100 
101 	/* On some boxes IRQ's during PnP BIOS calls are deadly.  */
102 	spin_lock_irqsave(&pnp_bios_lock, flags);
103 
104 	/* The lock prevents us bouncing CPU here */
105 	if (ts1_size)
106 		Q2_SET_SEL(smp_processor_id(), PNP_TS1, ts1_base, ts1_size);
107 	if (ts2_size)
108 		Q2_SET_SEL(smp_processor_id(), PNP_TS2, ts2_base, ts2_size);
109 
110 	__asm__ __volatile__("pushl %%ebp\n\t"
111 			     "pushl %%edi\n\t"
112 			     "pushl %%esi\n\t"
113 			     "pushl %%ds\n\t"
114 			     "pushl %%es\n\t"
115 			     "pushl %%fs\n\t"
116 			     "pushl %%gs\n\t"
117 			     "pushfl\n\t"
118 			     "movl %%esp, pnp_bios_fault_esp\n\t"
119 			     "movl $1f, pnp_bios_fault_eip\n\t"
120 			     "lcall %5,%6\n\t"
121 			     "1:popfl\n\t"
122 			     "popl %%gs\n\t"
123 			     "popl %%fs\n\t"
124 			     "popl %%es\n\t"
125 			     "popl %%ds\n\t"
126 			     "popl %%esi\n\t"
127 			     "popl %%edi\n\t"
128 			     "popl %%ebp\n\t":"=a"(status)
129 			     :"0"((func) | (((u32) arg1) << 16)),
130 			     "b"((arg2) | (((u32) arg3) << 16)),
131 			     "c"((arg4) | (((u32) arg5) << 16)),
132 			     "d"((arg6) | (((u32) arg7) << 16)),
133 			     "i"(PNP_CS32), "i"(0)
134 			     :"memory");
135 	spin_unlock_irqrestore(&pnp_bios_lock, flags);
136 
137 	get_cpu_gdt_table(cpu)[0x40 / 8] = save_desc_40;
138 	put_cpu();
139 
140 	/* If we get here and this is set then the PnP BIOS faulted on us. */
141 	if (pnp_bios_is_utter_crap) {
142 		printk(KERN_ERR
143 		       "PnPBIOS: Warning! Your PnP BIOS caused a fatal error. Attempting to continue\n");
144 		printk(KERN_ERR
145 		       "PnPBIOS: You may need to reboot with the \"pnpbios=off\" option to operate stably\n");
146 		printk(KERN_ERR
147 		       "PnPBIOS: Check with your vendor for an updated BIOS\n");
148 	}
149 
150 	return status;
151 }
152 
153 void pnpbios_print_status(const char *module, u16 status)
154 {
155 	switch (status) {
156 	case PNP_SUCCESS:
157 		printk(KERN_ERR "PnPBIOS: %s: function successful\n", module);
158 		break;
159 	case PNP_NOT_SET_STATICALLY:
160 		printk(KERN_ERR "PnPBIOS: %s: unable to set static resources\n",
161 		       module);
162 		break;
163 	case PNP_UNKNOWN_FUNCTION:
164 		printk(KERN_ERR "PnPBIOS: %s: invalid function number passed\n",
165 		       module);
166 		break;
167 	case PNP_FUNCTION_NOT_SUPPORTED:
168 		printk(KERN_ERR
169 		       "PnPBIOS: %s: function not supported on this system\n",
170 		       module);
171 		break;
172 	case PNP_INVALID_HANDLE:
173 		printk(KERN_ERR "PnPBIOS: %s: invalid handle\n", module);
174 		break;
175 	case PNP_BAD_PARAMETER:
176 		printk(KERN_ERR "PnPBIOS: %s: invalid parameters were passed\n",
177 		       module);
178 		break;
179 	case PNP_SET_FAILED:
180 		printk(KERN_ERR "PnPBIOS: %s: unable to set resources\n",
181 		       module);
182 		break;
183 	case PNP_EVENTS_NOT_PENDING:
184 		printk(KERN_ERR "PnPBIOS: %s: no events are pending\n", module);
185 		break;
186 	case PNP_SYSTEM_NOT_DOCKED:
187 		printk(KERN_ERR "PnPBIOS: %s: the system is not docked\n",
188 		       module);
189 		break;
190 	case PNP_NO_ISA_PNP_CARDS:
191 		printk(KERN_ERR
192 		       "PnPBIOS: %s: no isapnp cards are installed on this system\n",
193 		       module);
194 		break;
195 	case PNP_UNABLE_TO_DETERMINE_DOCK_CAPABILITIES:
196 		printk(KERN_ERR
197 		       "PnPBIOS: %s: cannot determine the capabilities of the docking station\n",
198 		       module);
199 		break;
200 	case PNP_CONFIG_CHANGE_FAILED_NO_BATTERY:
201 		printk(KERN_ERR
202 		       "PnPBIOS: %s: unable to undock, the system does not have a battery\n",
203 		       module);
204 		break;
205 	case PNP_CONFIG_CHANGE_FAILED_RESOURCE_CONFLICT:
206 		printk(KERN_ERR
207 		       "PnPBIOS: %s: could not dock due to resource conflicts\n",
208 		       module);
209 		break;
210 	case PNP_BUFFER_TOO_SMALL:
211 		printk(KERN_ERR "PnPBIOS: %s: the buffer passed is too small\n",
212 		       module);
213 		break;
214 	case PNP_USE_ESCD_SUPPORT:
215 		printk(KERN_ERR "PnPBIOS: %s: use ESCD instead\n", module);
216 		break;
217 	case PNP_MESSAGE_NOT_SUPPORTED:
218 		printk(KERN_ERR "PnPBIOS: %s: the message is unsupported\n",
219 		       module);
220 		break;
221 	case PNP_HARDWARE_ERROR:
222 		printk(KERN_ERR "PnPBIOS: %s: a hardware failure has occurred\n",
223 		       module);
224 		break;
225 	default:
226 		printk(KERN_ERR "PnPBIOS: %s: unexpected status 0x%x\n", module,
227 		       status);
228 		break;
229 	}
230 }
231 
232 /*
233  * PnP BIOS Low Level Calls
234  */
235 
236 #define PNP_GET_NUM_SYS_DEV_NODES		0x00
237 #define PNP_GET_SYS_DEV_NODE			0x01
238 #define PNP_SET_SYS_DEV_NODE			0x02
239 #define PNP_GET_EVENT				0x03
240 #define PNP_SEND_MESSAGE			0x04
241 #define PNP_GET_DOCKING_STATION_INFORMATION	0x05
242 #define PNP_SET_STATIC_ALLOCED_RES_INFO		0x09
243 #define PNP_GET_STATIC_ALLOCED_RES_INFO		0x0a
244 #define PNP_GET_APM_ID_TABLE			0x0b
245 #define PNP_GET_PNP_ISA_CONFIG_STRUC		0x40
246 #define PNP_GET_ESCD_INFO			0x41
247 #define PNP_READ_ESCD				0x42
248 #define PNP_WRITE_ESCD				0x43
249 
250 /*
251  * Call PnP BIOS with function 0x00, "get number of system device nodes"
252  */
253 static int __pnp_bios_dev_node_info(struct pnp_dev_node_info *data)
254 {
255 	u16 status;
256 
257 	if (!pnp_bios_present())
258 		return PNP_FUNCTION_NOT_SUPPORTED;
259 	status = call_pnp_bios(PNP_GET_NUM_SYS_DEV_NODES, 0, PNP_TS1, 2,
260 			       PNP_TS1, PNP_DS, 0, 0, data,
261 			       sizeof(struct pnp_dev_node_info), NULL, 0);
262 	data->no_nodes &= 0xff;
263 	return status;
264 }
265 
266 int pnp_bios_dev_node_info(struct pnp_dev_node_info *data)
267 {
268 	int status = __pnp_bios_dev_node_info(data);
269 
270 	if (status)
271 		pnpbios_print_status("dev_node_info", status);
272 	return status;
273 }
274 
275 /*
276  * Note that some PnP BIOSes (e.g., on Sony Vaio laptops) die a horrible
277  * death if they are asked to access the "current" configuration.
278  * Therefore, if it's a matter of indifference, it's better to call
279  * get_dev_node() and set_dev_node() with boot=1 rather than with boot=0.
280  */
281 
282 /*
283  * Call PnP BIOS with function 0x01, "get system device node"
284  * Input: *nodenum = desired node,
285  *        boot = whether to get nonvolatile boot (!=0)
286  *               or volatile current (0) config
287  * Output: *nodenum=next node or 0xff if no more nodes
288  */
289 static int __pnp_bios_get_dev_node(u8 *nodenum, char boot,
290 				   struct pnp_bios_node *data)
291 {
292 	u16 status;
293 	u16 tmp_nodenum;
294 
295 	if (!pnp_bios_present())
296 		return PNP_FUNCTION_NOT_SUPPORTED;
297 	if (!boot && pnpbios_dont_use_current_config)
298 		return PNP_FUNCTION_NOT_SUPPORTED;
299 	tmp_nodenum = *nodenum;
300 	status = call_pnp_bios(PNP_GET_SYS_DEV_NODE, 0, PNP_TS1, 0, PNP_TS2,
301 			       boot ? 2 : 1, PNP_DS, 0, &tmp_nodenum,
302 			       sizeof(tmp_nodenum), data, 65536);
303 	*nodenum = tmp_nodenum;
304 	return status;
305 }
306 
307 int pnp_bios_get_dev_node(u8 *nodenum, char boot, struct pnp_bios_node *data)
308 {
309 	int status;
310 
311 	status = __pnp_bios_get_dev_node(nodenum, boot, data);
312 	if (status)
313 		pnpbios_print_status("get_dev_node", status);
314 	return status;
315 }
316 
317 /*
318  * Call PnP BIOS with function 0x02, "set system device node"
319  * Input: *nodenum = desired node,
320  *        boot = whether to set nonvolatile boot (!=0)
321  *               or volatile current (0) config
322  */
323 static int __pnp_bios_set_dev_node(u8 nodenum, char boot,
324 				   struct pnp_bios_node *data)
325 {
326 	u16 status;
327 
328 	if (!pnp_bios_present())
329 		return PNP_FUNCTION_NOT_SUPPORTED;
330 	if (!boot && pnpbios_dont_use_current_config)
331 		return PNP_FUNCTION_NOT_SUPPORTED;
332 	status = call_pnp_bios(PNP_SET_SYS_DEV_NODE, nodenum, 0, PNP_TS1,
333 			       boot ? 2 : 1, PNP_DS, 0, 0, data, 65536, NULL,
334 			       0);
335 	return status;
336 }
337 
338 int pnp_bios_set_dev_node(u8 nodenum, char boot, struct pnp_bios_node *data)
339 {
340 	int status;
341 
342 	status = __pnp_bios_set_dev_node(nodenum, boot, data);
343 	if (status) {
344 		pnpbios_print_status("set_dev_node", status);
345 		return status;
346 	}
347 	if (!boot) {		/* Update devlist */
348 		status = pnp_bios_get_dev_node(&nodenum, boot, data);
349 		if (status)
350 			return status;
351 	}
352 	return status;
353 }
354 
355 /*
356  * Call PnP BIOS with function 0x05, "get docking station information"
357  */
358 int pnp_bios_dock_station_info(struct pnp_docking_station_info *data)
359 {
360 	u16 status;
361 
362 	if (!pnp_bios_present())
363 		return PNP_FUNCTION_NOT_SUPPORTED;
364 	status = call_pnp_bios(PNP_GET_DOCKING_STATION_INFORMATION, 0, PNP_TS1,
365 			       PNP_DS, 0, 0, 0, 0, data,
366 			       sizeof(struct pnp_docking_station_info), NULL,
367 			       0);
368 	return status;
369 }
370 
371 /*
372  * Call PnP BIOS with function 0x0a, "get statically allocated resource
373  * information"
374  */
375 static int __pnp_bios_get_stat_res(char *info)
376 {
377 	u16 status;
378 
379 	if (!pnp_bios_present())
380 		return PNP_FUNCTION_NOT_SUPPORTED;
381 	status = call_pnp_bios(PNP_GET_STATIC_ALLOCED_RES_INFO, 0, PNP_TS1,
382 			       PNP_DS, 0, 0, 0, 0, info, 65536, NULL, 0);
383 	return status;
384 }
385 
386 int pnp_bios_get_stat_res(char *info)
387 {
388 	int status;
389 
390 	status = __pnp_bios_get_stat_res(info);
391 	if (status)
392 		pnpbios_print_status("get_stat_res", status);
393 	return status;
394 }
395 
396 /*
397  * Call PnP BIOS with function 0x40, "get isa pnp configuration structure"
398  */
399 static int __pnp_bios_isapnp_config(struct pnp_isa_config_struc *data)
400 {
401 	u16 status;
402 
403 	if (!pnp_bios_present())
404 		return PNP_FUNCTION_NOT_SUPPORTED;
405 	status = call_pnp_bios(PNP_GET_PNP_ISA_CONFIG_STRUC, 0, PNP_TS1, PNP_DS,
406 			       0, 0, 0, 0, data,
407 			       sizeof(struct pnp_isa_config_struc), NULL, 0);
408 	return status;
409 }
410 
411 int pnp_bios_isapnp_config(struct pnp_isa_config_struc *data)
412 {
413 	int status;
414 
415 	status = __pnp_bios_isapnp_config(data);
416 	if (status)
417 		pnpbios_print_status("isapnp_config", status);
418 	return status;
419 }
420 
421 /*
422  * Call PnP BIOS with function 0x41, "get ESCD info"
423  */
424 static int __pnp_bios_escd_info(struct escd_info_struc *data)
425 {
426 	u16 status;
427 
428 	if (!pnp_bios_present())
429 		return ESCD_FUNCTION_NOT_SUPPORTED;
430 	status = call_pnp_bios(PNP_GET_ESCD_INFO, 0, PNP_TS1, 2, PNP_TS1, 4,
431 			       PNP_TS1, PNP_DS, data,
432 			       sizeof(struct escd_info_struc), NULL, 0);
433 	return status;
434 }
435 
436 int pnp_bios_escd_info(struct escd_info_struc *data)
437 {
438 	int status;
439 
440 	status = __pnp_bios_escd_info(data);
441 	if (status)
442 		pnpbios_print_status("escd_info", status);
443 	return status;
444 }
445 
446 /*
447  * Call PnP BIOS function 0x42, "read ESCD"
448  * nvram_base is determined by calling escd_info
449  */
450 static int __pnp_bios_read_escd(char *data, u32 nvram_base)
451 {
452 	u16 status;
453 
454 	if (!pnp_bios_present())
455 		return ESCD_FUNCTION_NOT_SUPPORTED;
456 	status = call_pnp_bios(PNP_READ_ESCD, 0, PNP_TS1, PNP_TS2, PNP_DS, 0, 0,
457 			       0, data, 65536, __va(nvram_base), 65536);
458 	return status;
459 }
460 
461 int pnp_bios_read_escd(char *data, u32 nvram_base)
462 {
463 	int status;
464 
465 	status = __pnp_bios_read_escd(data, nvram_base);
466 	if (status)
467 		pnpbios_print_status("read_escd", status);
468 	return status;
469 }
470 
471 void pnpbios_calls_init(union pnp_bios_install_struct *header)
472 {
473 	int i;
474 
475 	spin_lock_init(&pnp_bios_lock);
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_table(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