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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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +09007#include <linux/slab.h>
Alexey Dobriyan129f6942005-06-23 00:08:33 -07008#include <linux/module.h>
Rusty Russellbd472c72006-12-07 02:14:08 +01009#include <linux/uaccess.h>
Jaswinder Singh Rajput82487712008-12-27 18:32:28 +053010#include <asm/pci_x86.h>
Ingo Molnar1164dd02009-01-28 19:34:09 +010011#include <asm/pci-functions.h>
Matthieu Castet5bd5a452010-11-16 22:31:26 +010012#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013
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
Matthieu Castet5bd5a452010-11-16 22:31:26 +010029int 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 */
42static 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)
Wang YanQing819a6932011-12-08 12:00:27 +080047 printk(KERN_INFO "PCI : PCI BIOS area is rw and x. Use pci=nobios if you want it NX.\n");
Matthieu Castet5bd5a452010-11-16 22:31:26 +010048}
49
Linus Torvalds1da177e2005-04-16 15:20:36 -070050/*
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
60union 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
79static struct {
80 unsigned long address;
81 unsigned short segment;
Mathias Krause615f7752014-08-25 23:26:39 +020082} bios32_indirect __initdata = { 0, __KERNEL_CS };
Linus Torvalds1da177e2005-04-16 15:20:36 -070083
84/*
85 * Returns the entry point for the given service, NULL on error
86 */
87
Mathias Krause615f7752014-08-25 23:26:39 +020088static unsigned long __init bios32_service(unsigned long service)
Linus Torvalds1da177e2005-04-16 15:20:36 -070089{
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
120static struct {
121 unsigned long address;
122 unsigned short segment;
123} pci_indirect = { 0, __KERNEL_CS };
124
125static int pci_bios_present;
126
Mathias Krause615f7752014-08-25 23:26:39 +0200127static int __init check_pcibios(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128{
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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177static 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;
Geliang Tang96ae6462015-12-07 22:24:24 +0800183 u16 number = 0, mask = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184
Jan Beulichdb34a362011-07-22 08:13:05 +0100185 WARN_ON(seg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 if (!value || (bus > 255) || (devfn > 255) || (reg > 255))
187 return -EINVAL;
188
Thomas Gleixnerd19f61f2010-02-17 14:35:25 +0000189 raw_spin_lock_irqsave(&pci_config_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190
191 switch (len) {
192 case 1:
Geliang Tang96ae6462015-12-07 22:24:24 +0800193 number = PCIBIOS_READ_CONFIG_BYTE;
194 mask = 0xff;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 break;
196 case 2:
Geliang Tang96ae6462015-12-07 22:24:24 +0800197 number = PCIBIOS_READ_CONFIG_WORD;
198 mask = 0xffff;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 break;
200 case 4:
Geliang Tang96ae6462015-12-07 22:24:24 +0800201 number = PCIBIOS_READ_CONFIG_DWORD;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 break;
203 }
204
Geliang Tang96ae6462015-12-07 22:24:24 +0800205 __asm__("lcall *(%%esi); cld\n\t"
206 "jc 1f\n\t"
207 "xor %%ah, %%ah\n"
208 "1:"
209 : "=c" (*value),
210 "=a" (result)
211 : "1" (number),
212 "b" (bx),
213 "D" ((long)reg),
214 "S" (&pci_indirect));
215 /*
216 * Zero-extend the result beyond 8 or 16 bits, do not trust the
217 * BIOS having done it:
218 */
219 if (mask)
220 *value &= mask;
221
Thomas Gleixnerd19f61f2010-02-17 14:35:25 +0000222 raw_spin_unlock_irqrestore(&pci_config_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223
224 return (int)((result & 0xff00) >> 8);
225}
226
227static int pci_bios_write(unsigned int seg, unsigned int bus,
228 unsigned int devfn, int reg, int len, u32 value)
229{
230 unsigned long result = 0;
231 unsigned long flags;
232 unsigned long bx = (bus << 8) | devfn;
Geliang Tang96ae6462015-12-07 22:24:24 +0800233 u16 number = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234
Jan Beulichdb34a362011-07-22 08:13:05 +0100235 WARN_ON(seg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 if ((bus > 255) || (devfn > 255) || (reg > 255))
237 return -EINVAL;
238
Thomas Gleixnerd19f61f2010-02-17 14:35:25 +0000239 raw_spin_lock_irqsave(&pci_config_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240
241 switch (len) {
242 case 1:
Geliang Tang96ae6462015-12-07 22:24:24 +0800243 number = PCIBIOS_WRITE_CONFIG_BYTE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 break;
245 case 2:
Geliang Tang96ae6462015-12-07 22:24:24 +0800246 number = PCIBIOS_WRITE_CONFIG_WORD;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 break;
248 case 4:
Geliang Tang96ae6462015-12-07 22:24:24 +0800249 number = PCIBIOS_WRITE_CONFIG_DWORD;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 break;
251 }
252
Geliang Tang96ae6462015-12-07 22:24:24 +0800253 __asm__("lcall *(%%esi); cld\n\t"
254 "jc 1f\n\t"
255 "xor %%ah, %%ah\n"
256 "1:"
257 : "=a" (result)
258 : "0" (number),
259 "c" (value),
260 "b" (bx),
261 "D" ((long)reg),
262 "S" (&pci_indirect));
263
Thomas Gleixnerd19f61f2010-02-17 14:35:25 +0000264 raw_spin_unlock_irqrestore(&pci_config_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265
266 return (int)((result & 0xff00) >> 8);
267}
268
269
270/*
271 * Function table for BIOS32 access
272 */
273
Jan Beulich72da0b02011-09-15 08:58:51 +0100274static const struct pci_raw_ops pci_bios_access = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 .read = pci_bios_read,
276 .write = pci_bios_write
277};
278
279/*
280 * Try to find PCI BIOS.
281 */
282
Mathias Krause615f7752014-08-25 23:26:39 +0200283static const struct pci_raw_ops *__init pci_find_bios(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284{
285 union bios32 *check;
286 unsigned char sum;
287 int i, length;
288
289 /*
290 * Follow the standard procedure for locating the BIOS32 Service
291 * directory by scanning the permissible address range from
292 * 0xe0000 through 0xfffff for a valid BIOS32 structure.
293 */
294
295 for (check = (union bios32 *) __va(0xe0000);
296 check <= (union bios32 *) __va(0xffff0);
297 ++check) {
Rusty Russellbd472c72006-12-07 02:14:08 +0100298 long sig;
299 if (probe_kernel_address(&check->fields.signature, sig))
300 continue;
301
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302 if (check->fields.signature != BIOS32_SIGNATURE)
303 continue;
304 length = check->fields.length * 16;
305 if (!length)
306 continue;
307 sum = 0;
308 for (i = 0; i < length ; ++i)
309 sum += check->chars[i];
310 if (sum != 0)
311 continue;
312 if (check->fields.revision != 0) {
313 printk("PCI: unsupported BIOS32 revision %d at 0x%p\n",
314 check->fields.revision, check);
315 continue;
316 }
317 DBG("PCI: BIOS32 Service Directory structure at 0x%p\n", check);
318 if (check->fields.entry >= 0x100000) {
Rusty Russellbd472c72006-12-07 02:14:08 +0100319 printk("PCI: BIOS32 entry (0x%p) in high memory, "
320 "cannot use.\n", check);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 return NULL;
322 } else {
323 unsigned long bios32_entry = check->fields.entry;
Rusty Russellbd472c72006-12-07 02:14:08 +0100324 DBG("PCI: BIOS32 Service Directory entry at 0x%lx\n",
325 bios32_entry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326 bios32_indirect.address = bios32_entry + PAGE_OFFSET;
Matthieu Castet5bd5a452010-11-16 22:31:26 +0100327 set_bios_x();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 if (check_pcibios())
329 return &pci_bios_access;
330 }
331 break; /* Hopefully more than one BIOS32 cannot happen... */
332 }
333
334 return NULL;
335}
336
337/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338 * BIOS Functions for IRQ Routing
339 */
340
341struct irq_routing_options {
342 u16 size;
343 struct irq_info *table;
344 u16 segment;
345} __attribute__((packed));
346
Ralf Baechle4dd5bb92007-08-23 19:45:49 +0100347struct irq_routing_table * pcibios_get_irq_routing_table(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348{
349 struct irq_routing_options opt;
350 struct irq_routing_table *rt = NULL;
351 int ret, map;
352 unsigned long page;
353
354 if (!pci_bios_present)
355 return NULL;
356 page = __get_free_page(GFP_KERNEL);
357 if (!page)
358 return NULL;
359 opt.table = (struct irq_info *) page;
360 opt.size = PAGE_SIZE;
361 opt.segment = __KERNEL_DS;
362
363 DBG("PCI: Fetching IRQ routing table... ");
364 __asm__("push %%es\n\t"
365 "push %%ds\n\t"
366 "pop %%es\n\t"
367 "lcall *(%%esi); cld\n\t"
368 "pop %%es\n\t"
369 "jc 1f\n\t"
370 "xor %%ah, %%ah\n"
371 "1:"
372 : "=a" (ret),
373 "=b" (map),
374 "=m" (opt)
375 : "0" (PCIBIOS_GET_ROUTING_OPTIONS),
376 "1" (0),
377 "D" ((long) &opt),
378 "S" (&pci_indirect),
379 "m" (opt)
380 : "memory");
381 DBG("OK ret=%d, size=%d, map=%x\n", ret, opt.size, map);
382 if (ret & 0xff00)
383 printk(KERN_ERR "PCI: Error %02x when fetching IRQ routing table.\n", (ret >> 8) & 0xff);
384 else if (opt.size) {
385 rt = kmalloc(sizeof(struct irq_routing_table) + opt.size, GFP_KERNEL);
386 if (rt) {
387 memset(rt, 0, sizeof(struct irq_routing_table));
388 rt->size = opt.size + sizeof(struct irq_routing_table);
389 rt->exclusive_irqs = map;
390 memcpy(rt->slots, (void *) page, opt.size);
391 printk(KERN_INFO "PCI: Using BIOS Interrupt Routing Table\n");
392 }
393 }
394 free_page(page);
395 return rt;
396}
Alexey Dobriyan129f6942005-06-23 00:08:33 -0700397EXPORT_SYMBOL(pcibios_get_irq_routing_table);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398
399int pcibios_set_irq_routing(struct pci_dev *dev, int pin, int irq)
400{
401 int ret;
402
403 __asm__("lcall *(%%esi); cld\n\t"
404 "jc 1f\n\t"
405 "xor %%ah, %%ah\n"
406 "1:"
407 : "=a" (ret)
408 : "0" (PCIBIOS_SET_PCI_HW_INT),
409 "b" ((dev->bus->number << 8) | dev->devfn),
410 "c" ((irq << 8) | (pin + 10)),
411 "S" (&pci_indirect));
412 return !(ret & 0xff00);
413}
Alexey Dobriyan129f6942005-06-23 00:08:33 -0700414EXPORT_SYMBOL(pcibios_set_irq_routing);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415
Andi Kleen92c05fc2006-03-23 14:35:12 -0800416void __init pci_pcbios_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417{
418 if ((pci_probe & PCI_PROBE_BIOS)
419 && ((raw_pci_ops = pci_find_bios()))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 pci_bios_present = 1;
421 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422}
423