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bioscalls.c
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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 }
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