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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * BIOS32 and PCI BIOS handling.
3 */
4
5#include <linux/pci.h>
6#include <linux/init.h>
Alexey Dobriyan129f6942005-06-23 00:08:33 -07007#include <linux/module.h>
Rusty Russellbd472c72006-12-07 02:14:08 +01008#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07009#include "pci.h"
10#include "pci-functions.h"
11
12
13/* BIOS32 signature: "_32_" */
14#define BIOS32_SIGNATURE (('_' << 0) + ('3' << 8) + ('2' << 16) + ('_' << 24))
15
16/* PCI signature: "PCI " */
17#define PCI_SIGNATURE (('P' << 0) + ('C' << 8) + ('I' << 16) + (' ' << 24))
18
19/* PCI service signature: "$PCI" */
20#define PCI_SERVICE (('$' << 0) + ('P' << 8) + ('C' << 16) + ('I' << 24))
21
22/* PCI BIOS hardware mechanism flags */
23#define PCIBIOS_HW_TYPE1 0x01
24#define PCIBIOS_HW_TYPE2 0x02
25#define PCIBIOS_HW_TYPE1_SPEC 0x10
26#define PCIBIOS_HW_TYPE2_SPEC 0x20
27
28/*
29 * This is the standard structure used to identify the entry point
30 * to the BIOS32 Service Directory, as documented in
31 * Standard BIOS 32-bit Service Directory Proposal
32 * Revision 0.4 May 24, 1993
33 * Phoenix Technologies Ltd.
34 * Norwood, MA
35 * and the PCI BIOS specification.
36 */
37
38union bios32 {
39 struct {
40 unsigned long signature; /* _32_ */
41 unsigned long entry; /* 32 bit physical address */
42 unsigned char revision; /* Revision level, 0 */
43 unsigned char length; /* Length in paragraphs should be 01 */
44 unsigned char checksum; /* All bytes must add up to zero */
45 unsigned char reserved[5]; /* Must be zero */
46 } fields;
47 char chars[16];
48};
49
50/*
51 * Physical address of the service directory. I don't know if we're
52 * allowed to have more than one of these or not, so just in case
53 * we'll make pcibios_present() take a memory start parameter and store
54 * the array there.
55 */
56
57static struct {
58 unsigned long address;
59 unsigned short segment;
60} bios32_indirect = { 0, __KERNEL_CS };
61
62/*
63 * Returns the entry point for the given service, NULL on error
64 */
65
66static unsigned long bios32_service(unsigned long service)
67{
68 unsigned char return_code; /* %al */
69 unsigned long address; /* %ebx */
70 unsigned long length; /* %ecx */
71 unsigned long entry; /* %edx */
72 unsigned long flags;
73
74 local_irq_save(flags);
75 __asm__("lcall *(%%edi); cld"
76 : "=a" (return_code),
77 "=b" (address),
78 "=c" (length),
79 "=d" (entry)
80 : "0" (service),
81 "1" (0),
82 "D" (&bios32_indirect));
83 local_irq_restore(flags);
84
85 switch (return_code) {
86 case 0:
87 return address + entry;
88 case 0x80: /* Not present */
89 printk(KERN_WARNING "bios32_service(0x%lx): not present\n", service);
90 return 0;
91 default: /* Shouldn't happen */
92 printk(KERN_WARNING "bios32_service(0x%lx): returned 0x%x -- BIOS bug!\n",
93 service, return_code);
94 return 0;
95 }
96}
97
98static struct {
99 unsigned long address;
100 unsigned short segment;
101} pci_indirect = { 0, __KERNEL_CS };
102
103static int pci_bios_present;
104
105static int __devinit check_pcibios(void)
106{
107 u32 signature, eax, ebx, ecx;
108 u8 status, major_ver, minor_ver, hw_mech;
109 unsigned long flags, pcibios_entry;
110
111 if ((pcibios_entry = bios32_service(PCI_SERVICE))) {
112 pci_indirect.address = pcibios_entry + PAGE_OFFSET;
113
114 local_irq_save(flags);
115 __asm__(
116 "lcall *(%%edi); cld\n\t"
117 "jc 1f\n\t"
118 "xor %%ah, %%ah\n"
119 "1:"
120 : "=d" (signature),
121 "=a" (eax),
122 "=b" (ebx),
123 "=c" (ecx)
124 : "1" (PCIBIOS_PCI_BIOS_PRESENT),
125 "D" (&pci_indirect)
126 : "memory");
127 local_irq_restore(flags);
128
129 status = (eax >> 8) & 0xff;
130 hw_mech = eax & 0xff;
131 major_ver = (ebx >> 8) & 0xff;
132 minor_ver = ebx & 0xff;
133 if (pcibios_last_bus < 0)
134 pcibios_last_bus = ecx & 0xff;
135 DBG("PCI: BIOS probe returned s=%02x hw=%02x ver=%02x.%02x l=%02x\n",
136 status, hw_mech, major_ver, minor_ver, pcibios_last_bus);
137 if (status || signature != PCI_SIGNATURE) {
138 printk (KERN_ERR "PCI: BIOS BUG #%x[%08x] found\n",
139 status, signature);
140 return 0;
141 }
142 printk(KERN_INFO "PCI: PCI BIOS revision %x.%02x entry at 0x%lx, last bus=%d\n",
143 major_ver, minor_ver, pcibios_entry, pcibios_last_bus);
144#ifdef CONFIG_PCI_DIRECT
145 if (!(hw_mech & PCIBIOS_HW_TYPE1))
146 pci_probe &= ~PCI_PROBE_CONF1;
147 if (!(hw_mech & PCIBIOS_HW_TYPE2))
148 pci_probe &= ~PCI_PROBE_CONF2;
149#endif
150 return 1;
151 }
152 return 0;
153}
154
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155static int pci_bios_read(unsigned int seg, unsigned int bus,
156 unsigned int devfn, int reg, int len, u32 *value)
157{
158 unsigned long result = 0;
159 unsigned long flags;
160 unsigned long bx = (bus << 8) | devfn;
161
162 if (!value || (bus > 255) || (devfn > 255) || (reg > 255))
163 return -EINVAL;
164
165 spin_lock_irqsave(&pci_config_lock, flags);
166
167 switch (len) {
168 case 1:
169 __asm__("lcall *(%%esi); cld\n\t"
170 "jc 1f\n\t"
171 "xor %%ah, %%ah\n"
172 "1:"
173 : "=c" (*value),
174 "=a" (result)
175 : "1" (PCIBIOS_READ_CONFIG_BYTE),
176 "b" (bx),
177 "D" ((long)reg),
178 "S" (&pci_indirect));
Ingo Molnarf5dbb552008-03-10 18:04:34 +0100179 /*
180 * Zero-extend the result beyond 8 bits, do not trust the
181 * BIOS having done it:
182 */
183 *value &= 0xff;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 break;
185 case 2:
186 __asm__("lcall *(%%esi); cld\n\t"
187 "jc 1f\n\t"
188 "xor %%ah, %%ah\n"
189 "1:"
190 : "=c" (*value),
191 "=a" (result)
192 : "1" (PCIBIOS_READ_CONFIG_WORD),
193 "b" (bx),
194 "D" ((long)reg),
195 "S" (&pci_indirect));
Ingo Molnarf5dbb552008-03-10 18:04:34 +0100196 /*
197 * Zero-extend the result beyond 16 bits, do not trust the
198 * BIOS having done it:
199 */
200 *value &= 0xffff;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 break;
202 case 4:
203 __asm__("lcall *(%%esi); cld\n\t"
204 "jc 1f\n\t"
205 "xor %%ah, %%ah\n"
206 "1:"
207 : "=c" (*value),
208 "=a" (result)
209 : "1" (PCIBIOS_READ_CONFIG_DWORD),
210 "b" (bx),
211 "D" ((long)reg),
212 "S" (&pci_indirect));
213 break;
214 }
215
216 spin_unlock_irqrestore(&pci_config_lock, flags);
217
218 return (int)((result & 0xff00) >> 8);
219}
220
221static int pci_bios_write(unsigned int seg, unsigned int bus,
222 unsigned int devfn, int reg, int len, u32 value)
223{
224 unsigned long result = 0;
225 unsigned long flags;
226 unsigned long bx = (bus << 8) | devfn;
227
228 if ((bus > 255) || (devfn > 255) || (reg > 255))
229 return -EINVAL;
230
231 spin_lock_irqsave(&pci_config_lock, flags);
232
233 switch (len) {
234 case 1:
235 __asm__("lcall *(%%esi); cld\n\t"
236 "jc 1f\n\t"
237 "xor %%ah, %%ah\n"
238 "1:"
239 : "=a" (result)
240 : "0" (PCIBIOS_WRITE_CONFIG_BYTE),
241 "c" (value),
242 "b" (bx),
243 "D" ((long)reg),
244 "S" (&pci_indirect));
245 break;
246 case 2:
247 __asm__("lcall *(%%esi); cld\n\t"
248 "jc 1f\n\t"
249 "xor %%ah, %%ah\n"
250 "1:"
251 : "=a" (result)
252 : "0" (PCIBIOS_WRITE_CONFIG_WORD),
253 "c" (value),
254 "b" (bx),
255 "D" ((long)reg),
256 "S" (&pci_indirect));
257 break;
258 case 4:
259 __asm__("lcall *(%%esi); cld\n\t"
260 "jc 1f\n\t"
261 "xor %%ah, %%ah\n"
262 "1:"
263 : "=a" (result)
264 : "0" (PCIBIOS_WRITE_CONFIG_DWORD),
265 "c" (value),
266 "b" (bx),
267 "D" ((long)reg),
268 "S" (&pci_indirect));
269 break;
270 }
271
272 spin_unlock_irqrestore(&pci_config_lock, flags);
273
274 return (int)((result & 0xff00) >> 8);
275}
276
277
278/*
279 * Function table for BIOS32 access
280 */
281
282static struct pci_raw_ops pci_bios_access = {
283 .read = pci_bios_read,
284 .write = pci_bios_write
285};
286
287/*
288 * Try to find PCI BIOS.
289 */
290
291static struct pci_raw_ops * __devinit pci_find_bios(void)
292{
293 union bios32 *check;
294 unsigned char sum;
295 int i, length;
296
297 /*
298 * Follow the standard procedure for locating the BIOS32 Service
299 * directory by scanning the permissible address range from
300 * 0xe0000 through 0xfffff for a valid BIOS32 structure.
301 */
302
303 for (check = (union bios32 *) __va(0xe0000);
304 check <= (union bios32 *) __va(0xffff0);
305 ++check) {
Rusty Russellbd472c72006-12-07 02:14:08 +0100306 long sig;
307 if (probe_kernel_address(&check->fields.signature, sig))
308 continue;
309
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310 if (check->fields.signature != BIOS32_SIGNATURE)
311 continue;
312 length = check->fields.length * 16;
313 if (!length)
314 continue;
315 sum = 0;
316 for (i = 0; i < length ; ++i)
317 sum += check->chars[i];
318 if (sum != 0)
319 continue;
320 if (check->fields.revision != 0) {
321 printk("PCI: unsupported BIOS32 revision %d at 0x%p\n",
322 check->fields.revision, check);
323 continue;
324 }
325 DBG("PCI: BIOS32 Service Directory structure at 0x%p\n", check);
326 if (check->fields.entry >= 0x100000) {
Rusty Russellbd472c72006-12-07 02:14:08 +0100327 printk("PCI: BIOS32 entry (0x%p) in high memory, "
328 "cannot use.\n", check);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329 return NULL;
330 } else {
331 unsigned long bios32_entry = check->fields.entry;
Rusty Russellbd472c72006-12-07 02:14:08 +0100332 DBG("PCI: BIOS32 Service Directory entry at 0x%lx\n",
333 bios32_entry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334 bios32_indirect.address = bios32_entry + PAGE_OFFSET;
335 if (check_pcibios())
336 return &pci_bios_access;
337 }
338 break; /* Hopefully more than one BIOS32 cannot happen... */
339 }
340
341 return NULL;
342}
343
344/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 * BIOS Functions for IRQ Routing
346 */
347
348struct irq_routing_options {
349 u16 size;
350 struct irq_info *table;
351 u16 segment;
352} __attribute__((packed));
353
Ralf Baechle4dd5bb92007-08-23 19:45:49 +0100354struct irq_routing_table * pcibios_get_irq_routing_table(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355{
356 struct irq_routing_options opt;
357 struct irq_routing_table *rt = NULL;
358 int ret, map;
359 unsigned long page;
360
361 if (!pci_bios_present)
362 return NULL;
363 page = __get_free_page(GFP_KERNEL);
364 if (!page)
365 return NULL;
366 opt.table = (struct irq_info *) page;
367 opt.size = PAGE_SIZE;
368 opt.segment = __KERNEL_DS;
369
370 DBG("PCI: Fetching IRQ routing table... ");
371 __asm__("push %%es\n\t"
372 "push %%ds\n\t"
373 "pop %%es\n\t"
374 "lcall *(%%esi); cld\n\t"
375 "pop %%es\n\t"
376 "jc 1f\n\t"
377 "xor %%ah, %%ah\n"
378 "1:"
379 : "=a" (ret),
380 "=b" (map),
381 "=m" (opt)
382 : "0" (PCIBIOS_GET_ROUTING_OPTIONS),
383 "1" (0),
384 "D" ((long) &opt),
385 "S" (&pci_indirect),
386 "m" (opt)
387 : "memory");
388 DBG("OK ret=%d, size=%d, map=%x\n", ret, opt.size, map);
389 if (ret & 0xff00)
390 printk(KERN_ERR "PCI: Error %02x when fetching IRQ routing table.\n", (ret >> 8) & 0xff);
391 else if (opt.size) {
392 rt = kmalloc(sizeof(struct irq_routing_table) + opt.size, GFP_KERNEL);
393 if (rt) {
394 memset(rt, 0, sizeof(struct irq_routing_table));
395 rt->size = opt.size + sizeof(struct irq_routing_table);
396 rt->exclusive_irqs = map;
397 memcpy(rt->slots, (void *) page, opt.size);
398 printk(KERN_INFO "PCI: Using BIOS Interrupt Routing Table\n");
399 }
400 }
401 free_page(page);
402 return rt;
403}
Alexey Dobriyan129f6942005-06-23 00:08:33 -0700404EXPORT_SYMBOL(pcibios_get_irq_routing_table);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405
406int pcibios_set_irq_routing(struct pci_dev *dev, int pin, int irq)
407{
408 int ret;
409
410 __asm__("lcall *(%%esi); cld\n\t"
411 "jc 1f\n\t"
412 "xor %%ah, %%ah\n"
413 "1:"
414 : "=a" (ret)
415 : "0" (PCIBIOS_SET_PCI_HW_INT),
416 "b" ((dev->bus->number << 8) | dev->devfn),
417 "c" ((irq << 8) | (pin + 10)),
418 "S" (&pci_indirect));
419 return !(ret & 0xff00);
420}
Alexey Dobriyan129f6942005-06-23 00:08:33 -0700421EXPORT_SYMBOL(pcibios_set_irq_routing);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422
Andi Kleen92c05fc2006-03-23 14:35:12 -0800423void __init pci_pcbios_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424{
425 if ((pci_probe & PCI_PROBE_BIOS)
426 && ((raw_pci_ops = pci_find_bios()))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427 pci_bios_present = 1;
428 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429}
430