2 * BIOS32 and PCI BIOS handling.
6 #include <linux/init.h>
8 #include "pci-functions.h"
11 /* BIOS32 signature: "_32_" */
12 #define BIOS32_SIGNATURE (('_' << 0) + ('3' << 8) + ('2' << 16) + ('_' << 24))
14 /* PCI signature: "PCI " */
15 #define PCI_SIGNATURE (('P' << 0) + ('C' << 8) + ('I' << 16) + (' ' << 24))
17 /* PCI service signature: "$PCI" */
18 #define PCI_SERVICE (('$' << 0) + ('P' << 8) + ('C' << 16) + ('I' << 24))
20 /* PCI BIOS hardware mechanism flags */
21 #define PCIBIOS_HW_TYPE1 0x01
22 #define PCIBIOS_HW_TYPE2 0x02
23 #define PCIBIOS_HW_TYPE1_SPEC 0x10
24 #define PCIBIOS_HW_TYPE2_SPEC 0x20
27 * This is the standard structure used to identify the entry point
28 * to the BIOS32 Service Directory, as documented in
29 * Standard BIOS 32-bit Service Directory Proposal
30 * Revision 0.4 May 24, 1993
31 * Phoenix Technologies Ltd.
33 * and the PCI BIOS specification.
38 unsigned long signature; /* _32_ */
39 unsigned long entry; /* 32 bit physical address */
40 unsigned char revision; /* Revision level, 0 */
41 unsigned char length; /* Length in paragraphs should be 01 */
42 unsigned char checksum; /* All bytes must add up to zero */
43 unsigned char reserved[5]; /* Must be zero */
49 * Physical address of the service directory. I don't know if we're
50 * allowed to have more than one of these or not, so just in case
51 * we'll make pcibios_present() take a memory start parameter and store
56 unsigned long address;
57 unsigned short segment;
58 } bios32_indirect = { 0, __KERNEL_CS };
61 * Returns the entry point for the given service, NULL on error
64 static unsigned long bios32_service(unsigned long service)
66 unsigned char return_code; /* %al */
67 unsigned long address; /* %ebx */
68 unsigned long length; /* %ecx */
69 unsigned long entry; /* %edx */
72 local_irq_save(flags);
73 __asm__("lcall *(%%edi); cld"
80 "D" (&bios32_indirect));
81 local_irq_restore(flags);
83 switch (return_code) {
85 return address + entry;
86 case 0x80: /* Not present */
87 printk(KERN_WARNING "bios32_service(0x%lx): not present\n", service);
89 default: /* Shouldn't happen */
90 printk(KERN_WARNING "bios32_service(0x%lx): returned 0x%x -- BIOS bug!\n",
91 service, return_code);
97 unsigned long address;
98 unsigned short segment;
99 } pci_indirect = { 0, __KERNEL_CS };
101 static int pci_bios_present;
103 static int __devinit check_pcibios(void)
105 u32 signature, eax, ebx, ecx;
106 u8 status, major_ver, minor_ver, hw_mech;
107 unsigned long flags, pcibios_entry;
109 if ((pcibios_entry = bios32_service(PCI_SERVICE))) {
110 pci_indirect.address = pcibios_entry + PAGE_OFFSET;
112 local_irq_save(flags);
114 "lcall *(%%edi); cld\n\t"
122 : "1" (PCIBIOS_PCI_BIOS_PRESENT),
125 local_irq_restore(flags);
127 status = (eax >> 8) & 0xff;
128 hw_mech = eax & 0xff;
129 major_ver = (ebx >> 8) & 0xff;
130 minor_ver = ebx & 0xff;
131 if (pcibios_last_bus < 0)
132 pcibios_last_bus = ecx & 0xff;
133 DBG("PCI: BIOS probe returned s=%02x hw=%02x ver=%02x.%02x l=%02x\n",
134 status, hw_mech, major_ver, minor_ver, pcibios_last_bus);
135 if (status || signature != PCI_SIGNATURE) {
136 printk (KERN_ERR "PCI: BIOS BUG #%x[%08x] found\n",
140 printk(KERN_INFO "PCI: PCI BIOS revision %x.%02x entry at 0x%lx, last bus=%d\n",
141 major_ver, minor_ver, pcibios_entry, pcibios_last_bus);
142 #ifdef CONFIG_PCI_DIRECT
143 if (!(hw_mech & PCIBIOS_HW_TYPE1))
144 pci_probe &= ~PCI_PROBE_CONF1;
145 if (!(hw_mech & PCIBIOS_HW_TYPE2))
146 pci_probe &= ~PCI_PROBE_CONF2;
153 static int __devinit pci_bios_find_device (unsigned short vendor, unsigned short device_id,
154 unsigned short index, unsigned char *bus, unsigned char *device_fn)
159 __asm__("lcall *(%%edi); cld\n\t"
165 : "1" (PCIBIOS_FIND_PCI_DEVICE),
169 "D" (&pci_indirect));
170 *bus = (bx >> 8) & 0xff;
171 *device_fn = bx & 0xff;
172 return (int) (ret & 0xff00) >> 8;
175 static int pci_bios_read(unsigned int seg, unsigned int bus,
176 unsigned int devfn, int reg, int len, u32 *value)
178 unsigned long result = 0;
180 unsigned long bx = (bus << 8) | devfn;
182 if (!value || (bus > 255) || (devfn > 255) || (reg > 255))
185 spin_lock_irqsave(&pci_config_lock, flags);
189 __asm__("lcall *(%%esi); cld\n\t"
195 : "1" (PCIBIOS_READ_CONFIG_BYTE),
198 "S" (&pci_indirect));
201 __asm__("lcall *(%%esi); cld\n\t"
207 : "1" (PCIBIOS_READ_CONFIG_WORD),
210 "S" (&pci_indirect));
213 __asm__("lcall *(%%esi); cld\n\t"
219 : "1" (PCIBIOS_READ_CONFIG_DWORD),
222 "S" (&pci_indirect));
226 spin_unlock_irqrestore(&pci_config_lock, flags);
228 return (int)((result & 0xff00) >> 8);
231 static int pci_bios_write(unsigned int seg, unsigned int bus,
232 unsigned int devfn, int reg, int len, u32 value)
234 unsigned long result = 0;
236 unsigned long bx = (bus << 8) | devfn;
238 if ((bus > 255) || (devfn > 255) || (reg > 255))
241 spin_lock_irqsave(&pci_config_lock, flags);
245 __asm__("lcall *(%%esi); cld\n\t"
250 : "0" (PCIBIOS_WRITE_CONFIG_BYTE),
254 "S" (&pci_indirect));
257 __asm__("lcall *(%%esi); cld\n\t"
262 : "0" (PCIBIOS_WRITE_CONFIG_WORD),
266 "S" (&pci_indirect));
269 __asm__("lcall *(%%esi); cld\n\t"
274 : "0" (PCIBIOS_WRITE_CONFIG_DWORD),
278 "S" (&pci_indirect));
282 spin_unlock_irqrestore(&pci_config_lock, flags);
284 return (int)((result & 0xff00) >> 8);
289 * Function table for BIOS32 access
292 static struct pci_raw_ops pci_bios_access = {
293 .read = pci_bios_read,
294 .write = pci_bios_write
298 * Try to find PCI BIOS.
301 static struct pci_raw_ops * __devinit pci_find_bios(void)
308 * Follow the standard procedure for locating the BIOS32 Service
309 * directory by scanning the permissible address range from
310 * 0xe0000 through 0xfffff for a valid BIOS32 structure.
313 for (check = (union bios32 *) __va(0xe0000);
314 check <= (union bios32 *) __va(0xffff0);
316 if (check->fields.signature != BIOS32_SIGNATURE)
318 length = check->fields.length * 16;
322 for (i = 0; i < length ; ++i)
323 sum += check->chars[i];
326 if (check->fields.revision != 0) {
327 printk("PCI: unsupported BIOS32 revision %d at 0x%p\n",
328 check->fields.revision, check);
331 DBG("PCI: BIOS32 Service Directory structure at 0x%p\n", check);
332 if (check->fields.entry >= 0x100000) {
333 printk("PCI: BIOS32 entry (0x%p) in high memory, cannot use.\n", check);
336 unsigned long bios32_entry = check->fields.entry;
337 DBG("PCI: BIOS32 Service Directory entry at 0x%lx\n", bios32_entry);
338 bios32_indirect.address = bios32_entry + PAGE_OFFSET;
340 return &pci_bios_access;
342 break; /* Hopefully more than one BIOS32 cannot happen... */
349 * Sort the device list according to PCI BIOS. Nasty hack, but since some
350 * fool forgot to define the `correct' device order in the PCI BIOS specs
351 * and we want to be (possibly bug-to-bug ;-]) compatible with older kernels
352 * which used BIOS ordering, we are bound to do this...
355 void __devinit pcibios_sort(void)
357 LIST_HEAD(sorted_devices);
358 struct list_head *ln;
359 struct pci_dev *dev, *d;
361 unsigned char bus, devfn;
363 DBG("PCI: Sorting device list...\n");
364 while (!list_empty(&pci_devices)) {
365 ln = pci_devices.next;
368 while (pci_bios_find_device(dev->vendor, dev->device, idx, &bus, &devfn) == PCIBIOS_SUCCESSFUL) {
370 list_for_each(ln, &pci_devices) {
372 if (d->bus->number == bus && d->devfn == devfn) {
373 list_del(&d->global_list);
374 list_add_tail(&d->global_list, &sorted_devices);
380 if (ln == &pci_devices) {
381 printk(KERN_WARNING "PCI: BIOS reporting unknown device %02x:%02x\n", bus, devfn);
383 * We must not continue scanning as several buggy BIOSes
384 * return garbage after the last device. Grr.
390 printk(KERN_WARNING "PCI: Device %s not found by BIOS\n",
392 list_del(&dev->global_list);
393 list_add_tail(&dev->global_list, &sorted_devices);
396 list_splice(&sorted_devices, &pci_devices);
400 * BIOS Functions for IRQ Routing
403 struct irq_routing_options {
405 struct irq_info *table;
407 } __attribute__((packed));
409 struct irq_routing_table * __devinit pcibios_get_irq_routing_table(void)
411 struct irq_routing_options opt;
412 struct irq_routing_table *rt = NULL;
416 if (!pci_bios_present)
418 page = __get_free_page(GFP_KERNEL);
421 opt.table = (struct irq_info *) page;
422 opt.size = PAGE_SIZE;
423 opt.segment = __KERNEL_DS;
425 DBG("PCI: Fetching IRQ routing table... ");
426 __asm__("push %%es\n\t"
429 "lcall *(%%esi); cld\n\t"
437 : "0" (PCIBIOS_GET_ROUTING_OPTIONS),
443 DBG("OK ret=%d, size=%d, map=%x\n", ret, opt.size, map);
445 printk(KERN_ERR "PCI: Error %02x when fetching IRQ routing table.\n", (ret >> 8) & 0xff);
447 rt = kmalloc(sizeof(struct irq_routing_table) + opt.size, GFP_KERNEL);
449 memset(rt, 0, sizeof(struct irq_routing_table));
450 rt->size = opt.size + sizeof(struct irq_routing_table);
451 rt->exclusive_irqs = map;
452 memcpy(rt->slots, (void *) page, opt.size);
453 printk(KERN_INFO "PCI: Using BIOS Interrupt Routing Table\n");
461 int pcibios_set_irq_routing(struct pci_dev *dev, int pin, int irq)
465 __asm__("lcall *(%%esi); cld\n\t"
470 : "0" (PCIBIOS_SET_PCI_HW_INT),
471 "b" ((dev->bus->number << 8) | dev->devfn),
472 "c" ((irq << 8) | (pin + 10)),
473 "S" (&pci_indirect));
474 return !(ret & 0xff00);
477 static int __init pci_pcbios_init(void)
479 if ((pci_probe & PCI_PROBE_BIOS)
480 && ((raw_pci_ops = pci_find_bios()))) {
481 pci_probe |= PCI_BIOS_SORT;
482 pci_bios_present = 1;
487 arch_initcall(pci_pcbios_init);