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xen: cleancache shim to Xen Transcendent Memory
[linux-2.6/next.git] / arch / x86 / pci / pcbios.c
bloba5f7d0d63de0def1481382f785d0fc34d553f0f6
1 /*
2 * BIOS32 and PCI BIOS handling.
3 */
4
5 #include <linux/pci.h>
6 #include <linux/init.h>
7 #include <linux/slab.h>
8 #include <linux/module.h>
9 #include <linux/uaccess.h>
10 #include <asm/pci_x86.h>
11 #include <asm/pci-functions.h>
12 #include <asm/cacheflush.h>
13
14 /* BIOS32 signature: "_32_" */
15 #define BIOS32_SIGNATURE (('_' << 0) + ('3' << 8) + ('2' << 16) + ('_' << 24))
16
17 /* PCI signature: "PCI " */
18 #define PCI_SIGNATURE (('P' << 0) + ('C' << 8) + ('I' << 16) + (' ' << 24))
19
20 /* PCI service signature: "$PCI" */
21 #define PCI_SERVICE (('$' << 0) + ('P' << 8) + ('C' << 16) + ('I' << 24))
22
23 /* PCI BIOS hardware mechanism flags */
24 #define PCIBIOS_HW_TYPE1 0x01
25 #define PCIBIOS_HW_TYPE2 0x02
26 #define PCIBIOS_HW_TYPE1_SPEC 0x10
27 #define PCIBIOS_HW_TYPE2_SPEC 0x20
28
29 int pcibios_enabled;
30
31 /* According to the BIOS specification at:
32 * http://members.datafast.net.au/dft0802/specs/bios21.pdf, we could
33 * restrict the x zone to some pages and make it ro. But this may be
34 * broken on some bios, complex to handle with static_protections.
35 * We could make the 0xe0000-0x100000 range rox, but this can break
36 * some ISA mapping.
37 *
38 * So we let's an rw and x hole when pcibios is used. This shouldn't
39 * happen for modern system with mmconfig, and if you don't want it
40 * you could disable pcibios...
41 */
42 static inline void set_bios_x(void)
43 {
44 pcibios_enabled = 1;
45 set_memory_x(PAGE_OFFSET + BIOS_BEGIN, (BIOS_END - BIOS_BEGIN) >> PAGE_SHIFT);
46 if (__supported_pte_mask & _PAGE_NX)
47 printk(KERN_INFO "PCI : PCI BIOS aera is rw and x. Use pci=nobios if you want it NX.\n");
48 }
49
50 /*
51 * This is the standard structure used to identify the entry point
52 * to the BIOS32 Service Directory, as documented in
53 * Standard BIOS 32-bit Service Directory Proposal
54 * Revision 0.4 May 24, 1993
55 * Phoenix Technologies Ltd.
56 * Norwood, MA
57 * and the PCI BIOS specification.
58 */
59
60 union bios32 {
61 struct {
62 unsigned long signature; /* _32_ */
63 unsigned long entry; /* 32 bit physical address */
64 unsigned char revision; /* Revision level, 0 */
65 unsigned char length; /* Length in paragraphs should be 01 */
66 unsigned char checksum; /* All bytes must add up to zero */
67 unsigned char reserved[5]; /* Must be zero */
68 } fields;
69 char chars[16];
70 };
71
72 /*
73 * Physical address of the service directory. I don't know if we're
74 * allowed to have more than one of these or not, so just in case
75 * we'll make pcibios_present() take a memory start parameter and store
76 * the array there.
77 */
78
79 static struct {
80 unsigned long address;
81 unsigned short segment;
82 } bios32_indirect = { 0, __KERNEL_CS };
83
84 /*
85 * Returns the entry point for the given service, NULL on error
86 */
87
88 static unsigned long bios32_service(unsigned long service)
89 {
90 unsigned char return_code; /* %al */
91 unsigned long address; /* %ebx */
92 unsigned long length; /* %ecx */
93 unsigned long entry; /* %edx */
94 unsigned long flags;
95
96 local_irq_save(flags);
97 __asm__("lcall *(%%edi); cld"
98 : "=a" (return_code),
99 "=b" (address),
100 "=c" (length),
101 "=d" (entry)
102 : "0" (service),
103 "1" (0),
104 "D" (&bios32_indirect));
105 local_irq_restore(flags);
106
107 switch (return_code) {
108 case 0:
109 return address + entry;
110 case 0x80: /* Not present */
111 printk(KERN_WARNING "bios32_service(0x%lx): not present\n", service);
112 return 0;
113 default: /* Shouldn't happen */
114 printk(KERN_WARNING "bios32_service(0x%lx): returned 0x%x -- BIOS bug!\n",
115 service, return_code);
116 return 0;
117 }
118 }
119
120 static struct {
121 unsigned long address;
122 unsigned short segment;
123 } pci_indirect = { 0, __KERNEL_CS };
124
125 static int pci_bios_present;
126
127 static int __devinit check_pcibios(void)
128 {
129 u32 signature, eax, ebx, ecx;
130 u8 status, major_ver, minor_ver, hw_mech;
131 unsigned long flags, pcibios_entry;
132
133 if ((pcibios_entry = bios32_service(PCI_SERVICE))) {
134 pci_indirect.address = pcibios_entry + PAGE_OFFSET;
135
136 local_irq_save(flags);
137 __asm__(
138 "lcall *(%%edi); cld\n\t"
139 "jc 1f\n\t"
140 "xor %%ah, %%ah\n"
141 "1:"
142 : "=d" (signature),
143 "=a" (eax),
144 "=b" (ebx),
145 "=c" (ecx)
146 : "1" (PCIBIOS_PCI_BIOS_PRESENT),
147 "D" (&pci_indirect)
148 : "memory");
149 local_irq_restore(flags);
150
151 status = (eax >> 8) & 0xff;
152 hw_mech = eax & 0xff;
153 major_ver = (ebx >> 8) & 0xff;
154 minor_ver = ebx & 0xff;
155 if (pcibios_last_bus < 0)
156 pcibios_last_bus = ecx & 0xff;
157 DBG("PCI: BIOS probe returned s=%02x hw=%02x ver=%02x.%02x l=%02x\n",
158 status, hw_mech, major_ver, minor_ver, pcibios_last_bus);
159 if (status || signature != PCI_SIGNATURE) {
160 printk (KERN_ERR "PCI: BIOS BUG #%x[%08x] found\n",
161 status, signature);
162 return 0;
163 }
164 printk(KERN_INFO "PCI: PCI BIOS revision %x.%02x entry at 0x%lx, last bus=%d\n",
165 major_ver, minor_ver, pcibios_entry, pcibios_last_bus);
166 #ifdef CONFIG_PCI_DIRECT
167 if (!(hw_mech & PCIBIOS_HW_TYPE1))
168 pci_probe &= ~PCI_PROBE_CONF1;
169 if (!(hw_mech & PCIBIOS_HW_TYPE2))
170 pci_probe &= ~PCI_PROBE_CONF2;
171 #endif
172 return 1;
173 }
174 return 0;
175 }
176
177 static int pci_bios_read(unsigned int seg, unsigned int bus,
178 unsigned int devfn, int reg, int len, u32 *value)
179 {
180 unsigned long result = 0;
181 unsigned long flags;
182 unsigned long bx = (bus << 8) | devfn;
183
184 if (!value || (bus > 255) || (devfn > 255) || (reg > 255))
185 return -EINVAL;
186
187 raw_spin_lock_irqsave(&pci_config_lock, flags);
188
189 switch (len) {
190 case 1:
191 __asm__("lcall *(%%esi); cld\n\t"
192 "jc 1f\n\t"
193 "xor %%ah, %%ah\n"
194 "1:"
195 : "=c" (*value),
196 "=a" (result)
197 : "1" (PCIBIOS_READ_CONFIG_BYTE),
198 "b" (bx),
199 "D" ((long)reg),
200 "S" (&pci_indirect));
201 /*
202 * Zero-extend the result beyond 8 bits, do not trust the
203 * BIOS having done it:
204 */
205 *value &= 0xff;
206 break;
207 case 2:
208 __asm__("lcall *(%%esi); cld\n\t"
209 "jc 1f\n\t"
210 "xor %%ah, %%ah\n"
211 "1:"
212 : "=c" (*value),
213 "=a" (result)
214 : "1" (PCIBIOS_READ_CONFIG_WORD),
215 "b" (bx),
216 "D" ((long)reg),
217 "S" (&pci_indirect));
218 /*
219 * Zero-extend the result beyond 16 bits, do not trust the
220 * BIOS having done it:
221 */
222 *value &= 0xffff;
223 break;
224 case 4:
225 __asm__("lcall *(%%esi); cld\n\t"
226 "jc 1f\n\t"
227 "xor %%ah, %%ah\n"
228 "1:"
229 : "=c" (*value),
230 "=a" (result)
231 : "1" (PCIBIOS_READ_CONFIG_DWORD),
232 "b" (bx),
233 "D" ((long)reg),
234 "S" (&pci_indirect));
235 break;
236 }
237
238 raw_spin_unlock_irqrestore(&pci_config_lock, flags);
239
240 return (int)((result & 0xff00) >> 8);
241 }
242
243 static int pci_bios_write(unsigned int seg, unsigned int bus,
244 unsigned int devfn, int reg, int len, u32 value)
245 {
246 unsigned long result = 0;
247 unsigned long flags;
248 unsigned long bx = (bus << 8) | devfn;
249
250 if ((bus > 255) || (devfn > 255) || (reg > 255))
251 return -EINVAL;
252
253 raw_spin_lock_irqsave(&pci_config_lock, flags);
254
255 switch (len) {
256 case 1:
257 __asm__("lcall *(%%esi); cld\n\t"
258 "jc 1f\n\t"
259 "xor %%ah, %%ah\n"
260 "1:"
261 : "=a" (result)
262 : "0" (PCIBIOS_WRITE_CONFIG_BYTE),
263 "c" (value),
264 "b" (bx),
265 "D" ((long)reg),
266 "S" (&pci_indirect));
267 break;
268 case 2:
269 __asm__("lcall *(%%esi); cld\n\t"
270 "jc 1f\n\t"
271 "xor %%ah, %%ah\n"
272 "1:"
273 : "=a" (result)
274 : "0" (PCIBIOS_WRITE_CONFIG_WORD),
275 "c" (value),
276 "b" (bx),
277 "D" ((long)reg),
278 "S" (&pci_indirect));
279 break;
280 case 4:
281 __asm__("lcall *(%%esi); cld\n\t"
282 "jc 1f\n\t"
283 "xor %%ah, %%ah\n"
284 "1:"
285 : "=a" (result)
286 : "0" (PCIBIOS_WRITE_CONFIG_DWORD),
287 "c" (value),
288 "b" (bx),
289 "D" ((long)reg),
290 "S" (&pci_indirect));
291 break;
292 }
293
294 raw_spin_unlock_irqrestore(&pci_config_lock, flags);
295
296 return (int)((result & 0xff00) >> 8);
297 }
298
299
300 /*
301 * Function table for BIOS32 access
302 */
303
304 static struct pci_raw_ops pci_bios_access = {
305 .read = pci_bios_read,
306 .write = pci_bios_write
307 };
308
309 /*
310 * Try to find PCI BIOS.
311 */
312
313 static struct pci_raw_ops * __devinit pci_find_bios(void)
314 {
315 union bios32 *check;
316 unsigned char sum;
317 int i, length;
318
319 /*
320 * Follow the standard procedure for locating the BIOS32 Service
321 * directory by scanning the permissible address range from
322 * 0xe0000 through 0xfffff for a valid BIOS32 structure.
323 */
324
325 for (check = (union bios32 *) __va(0xe0000);
326 check <= (union bios32 *) __va(0xffff0);
327 ++check) {
328 long sig;
329 if (probe_kernel_address(&check->fields.signature, sig))
330 continue;
331
332 if (check->fields.signature != BIOS32_SIGNATURE)
333 continue;
334 length = check->fields.length * 16;
335 if (!length)
336 continue;
337 sum = 0;
338 for (i = 0; i < length ; ++i)
339 sum += check->chars[i];
340 if (sum != 0)
341 continue;
342 if (check->fields.revision != 0) {
343 printk("PCI: unsupported BIOS32 revision %d at 0x%p\n",
344 check->fields.revision, check);
345 continue;
346 }
347 DBG("PCI: BIOS32 Service Directory structure at 0x%p\n", check);
348 if (check->fields.entry >= 0x100000) {
349 printk("PCI: BIOS32 entry (0x%p) in high memory, "
350 "cannot use.\n", check);
351 return NULL;
352 } else {
353 unsigned long bios32_entry = check->fields.entry;
354 DBG("PCI: BIOS32 Service Directory entry at 0x%lx\n",
355 bios32_entry);
356 bios32_indirect.address = bios32_entry + PAGE_OFFSET;
357 set_bios_x();
358 if (check_pcibios())
359 return &pci_bios_access;
360 }
361 break; /* Hopefully more than one BIOS32 cannot happen... */
362 }
363
364 return NULL;
365 }
366
367 /*
368 * BIOS Functions for IRQ Routing
369 */
370
371 struct irq_routing_options {
372 u16 size;
373 struct irq_info *table;
374 u16 segment;
375 } __attribute__((packed));
376
377 struct irq_routing_table * pcibios_get_irq_routing_table(void)
378 {
379 struct irq_routing_options opt;
380 struct irq_routing_table *rt = NULL;
381 int ret, map;
382 unsigned long page;
383
384 if (!pci_bios_present)
385 return NULL;
386 page = __get_free_page(GFP_KERNEL);
387 if (!page)
388 return NULL;
389 opt.table = (struct irq_info *) page;
390 opt.size = PAGE_SIZE;
391 opt.segment = __KERNEL_DS;
392
393 DBG("PCI: Fetching IRQ routing table... ");
394 __asm__("push %%es\n\t"
395 "push %%ds\n\t"
396 "pop %%es\n\t"
397 "lcall *(%%esi); cld\n\t"
398 "pop %%es\n\t"
399 "jc 1f\n\t"
400 "xor %%ah, %%ah\n"
401 "1:"
402 : "=a" (ret),
403 "=b" (map),
404 "=m" (opt)
405 : "0" (PCIBIOS_GET_ROUTING_OPTIONS),
406 "1" (0),
407 "D" ((long) &opt),
408 "S" (&pci_indirect),
409 "m" (opt)
410 : "memory");
411 DBG("OK ret=%d, size=%d, map=%x\n", ret, opt.size, map);
412 if (ret & 0xff00)
413 printk(KERN_ERR "PCI: Error %02x when fetching IRQ routing table.\n", (ret >> 8) & 0xff);
414 else if (opt.size) {
415 rt = kmalloc(sizeof(struct irq_routing_table) + opt.size, GFP_KERNEL);
416 if (rt) {
417 memset(rt, 0, sizeof(struct irq_routing_table));
418 rt->size = opt.size + sizeof(struct irq_routing_table);
419 rt->exclusive_irqs = map;
420 memcpy(rt->slots, (void *) page, opt.size);
421 printk(KERN_INFO "PCI: Using BIOS Interrupt Routing Table\n");
422 }
423 }
424 free_page(page);
425 return rt;
426 }
427 EXPORT_SYMBOL(pcibios_get_irq_routing_table);
428
429 int pcibios_set_irq_routing(struct pci_dev *dev, int pin, int irq)
430 {
431 int ret;
432
433 __asm__("lcall *(%%esi); cld\n\t"
434 "jc 1f\n\t"
435 "xor %%ah, %%ah\n"
436 "1:"
437 : "=a" (ret)
438 : "0" (PCIBIOS_SET_PCI_HW_INT),
439 "b" ((dev->bus->number << 8) | dev->devfn),
440 "c" ((irq << 8) | (pin + 10)),
441 "S" (&pci_indirect));
442 return !(ret & 0xff00);
443 }
444 EXPORT_SYMBOL(pcibios_set_irq_routing);
445
446 void __init pci_pcbios_init(void)
447 {
448 if ((pci_probe & PCI_PROBE_BIOS)
449 && ((raw_pci_ops = pci_find_bios()))) {
450 pci_bios_present = 1;
451 }
452 }
453
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