> Well, as Alan pointed out, that's an error recovery routine only triggered
> by large numbers of spurious interrupts. Since we can't always be sure that
> spurios interrupts are an error, we read STATUS1 in order to find out if
> there *is* an actual error condition outstanding. If there is, we clear it
> and go on. Without this code, it's possible to have a single PCI error
> condition throw the machine into an interrupt storm under 2.1.x and lock the
> machine under 2.0.x. Now, these conditions are rare, and the PCI parity
> checking stuff is turned off at detect time by default (at least in the
> latest driver), but if it is enabled, then we need to either be able to get
> at that register, or I have to create some sort of timer/bottom_half/other
> non-interrupt function to correct the error condition.
Try the following patch. If it works, I'll send it to Linus for inclusion
in 2.1.107.
Have a nice fortnight
-- Martin `MJ' Mares <mj@ucw.cz> http://atrey.karlin.mff.cuni.cz/~mj/ Faculty of Math and Physics, Charles University, Prague, Czech Rep., Earth "Ctrl and Alt keys stuck -- press Del to continue."
--- linux-2.1/arch/i386/kernel/bios32.c Fri Jun 19 19:19:09 1998 +++ linux/arch/i386/kernel/bios32.c Fri Jun 19 19:25:47 1998 @@ -1,7 +1,7 @@ /* * bios32.c - Low-Level PCI Access * - * $Id: bios32.c,v 1.33 1998/05/12 07:30:11 mj Exp $ + * $Id: bios32.c,v 1.37 1998/06/19 17:11:37 mj Exp $ * * Copyright 1993, 1994 Drew Eckhardt * Visionary Computing @@ -62,6 +62,9 @@ * Feb 6, 1998 : No longer using BIOS to find devices and device classes. [mj] * * May 1, 1998 : Support for peer host bridges. [mj] + * + * Jun 19, 1998 : Changed to use spinlocks, so that PCI configuration space + * can be accessed from interrupts even on SMP systems. [mj] */ #include <linux/config.h> @@ -76,11 +79,8 @@ #include <asm/segment.h> #include <asm/system.h> #include <asm/io.h> - -#include <linux/smp_lock.h> -#include <asm/irq.h> -#include <asm/bitops.h> #include <asm/smp.h> +#include <asm/spinlock.h> #include "irq.h" @@ -93,6 +93,13 @@ #endif /* + * This interrupt-safe spinlock protects all accesses to PCI + * configuration space. + */ + +spinlock_t pci_lock = SPIN_LOCK_UNLOCKED; + +/* * Generic PCI access -- indirect calls according to detected HW. */ @@ -128,41 +135,28 @@ return access_pci->pci_present; } -int pcibios_read_config_byte (unsigned char bus, - unsigned char device_fn, unsigned char where, unsigned char *value) -{ - return access_pci->read_config_byte(bus, device_fn, where, value); -} - -int pcibios_read_config_word (unsigned char bus, - unsigned char device_fn, unsigned char where, unsigned short *value) -{ - return access_pci->read_config_word(bus, device_fn, where, value); -} - -int pcibios_read_config_dword (unsigned char bus, - unsigned char device_fn, unsigned char where, unsigned int *value) -{ - return access_pci->read_config_dword(bus, device_fn, where, value); -} - -int pcibios_write_config_byte (unsigned char bus, - unsigned char device_fn, unsigned char where, unsigned char value) -{ - return access_pci->write_config_byte(bus, device_fn, where, value); -} - -int pcibios_write_config_word (unsigned char bus, - unsigned char device_fn, unsigned char where, unsigned short value) -{ - return access_pci->write_config_word(bus, device_fn, where, value); -} - -int pcibios_write_config_dword (unsigned char bus, - unsigned char device_fn, unsigned char where, unsigned int value) -{ - return access_pci->write_config_dword(bus, device_fn, where, value); -} +#define PCI_byte_BAD 0 +#define PCI_word_BAD (pos & 1) +#define PCI_dword_BAD (pos & 3) + +#define PCI_STUB(rw,size,type) \ +int pcibios_##rw##_config_##size (u8 bus, u8 dfn, u8 pos, type value) \ +{ \ + int res; \ + unsigned long flags; \ + if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \ + spin_lock_irqsave(&pci_lock, flags); \ + res = access_pci->rw##_config_##size(bus, dfn, pos, value); \ + spin_unlock_irqrestore(&pci_lock, flags); \ + return res; \ +} + +PCI_STUB(read, byte, u8 *) +PCI_STUB(read, word, u16 *) +PCI_STUB(read, dword, u32 *) +PCI_STUB(write, byte, u8) +PCI_STUB(write, word, u16) +PCI_STUB(write, dword, u32) #define PCI_PROBE_BIOS 1 #define PCI_PROBE_CONF1 2 @@ -187,76 +181,48 @@ static int pci_conf1_read_config_byte(unsigned char bus, unsigned char device_fn, unsigned char where, unsigned char *value) { - unsigned long flags; - - save_flags(flags); cli(); outl(CONFIG_CMD(bus,device_fn,where), 0xCF8); *value = inb(0xCFC + (where&3)); - restore_flags(flags); return PCIBIOS_SUCCESSFUL; } static int pci_conf1_read_config_word (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned short *value) { - unsigned long flags; - - if (where&1) return PCIBIOS_BAD_REGISTER_NUMBER; - save_flags(flags); cli(); outl(CONFIG_CMD(bus,device_fn,where), 0xCF8); *value = inw(0xCFC + (where&2)); - restore_flags(flags); return PCIBIOS_SUCCESSFUL; } static int pci_conf1_read_config_dword (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned int *value) { - unsigned long flags; - - if (where&3) return PCIBIOS_BAD_REGISTER_NUMBER; - save_flags(flags); cli(); outl(CONFIG_CMD(bus,device_fn,where), 0xCF8); *value = inl(0xCFC); - restore_flags(flags); return PCIBIOS_SUCCESSFUL; } static int pci_conf1_write_config_byte (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned char value) { - unsigned long flags; - - save_flags(flags); cli(); outl(CONFIG_CMD(bus,device_fn,where), 0xCF8); outb(value, 0xCFC + (where&3)); - restore_flags(flags); return PCIBIOS_SUCCESSFUL; } static int pci_conf1_write_config_word (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned short value) { - unsigned long flags; - - if (where&1) return PCIBIOS_BAD_REGISTER_NUMBER; - save_flags(flags); cli(); outl(CONFIG_CMD(bus,device_fn,where), 0xCF8); outw(value, 0xCFC + (where&2)); - restore_flags(flags); return PCIBIOS_SUCCESSFUL; } static int pci_conf1_write_config_dword (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned int value) { - unsigned long flags; - - if (where&3) return PCIBIOS_BAD_REGISTER_NUMBER; - save_flags(flags); cli(); outl(CONFIG_CMD(bus,device_fn,where), 0xCF8); outl(value, 0xCFC); - restore_flags(flags); return PCIBIOS_SUCCESSFUL; } @@ -282,90 +248,72 @@ static int pci_conf2_read_config_byte(unsigned char bus, unsigned char device_fn, unsigned char where, unsigned char *value) { - unsigned long flags; - if (device_fn & 0x80) return PCIBIOS_DEVICE_NOT_FOUND; - save_flags(flags); cli(); outb (FUNC(device_fn), 0xCF8); outb (bus, 0xCFA); *value = inb(IOADDR(device_fn,where)); outb (0, 0xCF8); - restore_flags(flags); return PCIBIOS_SUCCESSFUL; } static int pci_conf2_read_config_word (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned short *value) { - unsigned long flags; - if (device_fn & 0x80) return PCIBIOS_DEVICE_NOT_FOUND; - save_flags(flags); cli(); outb (FUNC(device_fn), 0xCF8); outb (bus, 0xCFA); *value = inw(IOADDR(device_fn,where)); outb (0, 0xCF8); - restore_flags(flags); return PCIBIOS_SUCCESSFUL; } static int pci_conf2_read_config_dword (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned int *value) { - unsigned long flags; - if (device_fn & 0x80) return PCIBIOS_DEVICE_NOT_FOUND; - save_flags(flags); cli(); outb (FUNC(device_fn), 0xCF8); outb (bus, 0xCFA); *value = inl (IOADDR(device_fn,where)); outb (0, 0xCF8); - restore_flags(flags); return PCIBIOS_SUCCESSFUL; } static int pci_conf2_write_config_byte (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned char value) { - unsigned long flags; - - save_flags(flags); cli(); + if (device_fn & 0x80) + return PCIBIOS_DEVICE_NOT_FOUND; outb (FUNC(device_fn), 0xCF8); outb (bus, 0xCFA); outb (value, IOADDR(device_fn,where)); outb (0, 0xCF8); - restore_flags(flags); return PCIBIOS_SUCCESSFUL; } static int pci_conf2_write_config_word (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned short value) { - unsigned long flags; - - save_flags(flags); cli(); + if (device_fn & 0x80) + return PCIBIOS_DEVICE_NOT_FOUND; outb (FUNC(device_fn), 0xCF8); outb (bus, 0xCFA); outw (value, IOADDR(device_fn,where)); outb (0, 0xCF8); - restore_flags(flags); return PCIBIOS_SUCCESSFUL; } static int pci_conf2_write_config_dword (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned int value) { - unsigned long flags; - - save_flags(flags); cli(); + if (device_fn & 0x80) + return PCIBIOS_DEVICE_NOT_FOUND; outb (FUNC(device_fn), 0xCF8); outb (bus, 0xCFA); outl (value, IOADDR(device_fn,where)); outb (0, 0xCF8); - restore_flags(flags); return PCIBIOS_SUCCESSFUL; } @@ -387,7 +335,7 @@ unsigned int tmp; unsigned long flags; - save_flags(flags); cli(); + __save_flags(flags); __cli(); /* * Check if configuration type 1 works. @@ -398,7 +346,7 @@ outl (0x80000000, 0xCF8); if (inl (0xCF8) == 0x80000000) { outl (tmp, 0xCF8); - restore_flags(flags); + __restore_flags(flags); printk("PCI: Using configuration type 1\n"); return &pci_direct_conf1; } @@ -413,13 +361,13 @@ outb (0x00, 0xCF8); outb (0x00, 0xCFA); if (inb (0xCF8) == 0x00 && inb (0xCFA) == 0x00) { - restore_flags(flags); + __restore_flags(flags); printk("PCI: Using configuration type 2\n"); return &pci_direct_conf2; } } - restore_flags(flags); + __restore_flags(flags); return NULL; } @@ -504,7 +452,7 @@ unsigned long entry; /* %edx */ unsigned long flags; - save_flags(flags); cli(); + spin_lock_irqsave(&pci_lock, flags); __asm__("lcall (%%edi)" : "=a" (return_code), "=b" (address), @@ -513,7 +461,7 @@ : "0" (service), "1" (0), "D" (&bios32_indirect)); - restore_flags(flags); + spin_unlock_irqrestore(&pci_lock, flags); switch (return_code) { case 0: @@ -542,8 +490,8 @@ if ((pcibios_entry = bios32_service(PCI_SERVICE))) { pci_indirect.address = pcibios_entry + PAGE_OFFSET; - save_flags(flags); cli(); - __asm__ __volatile__( + __save_flags(flags); __cli(); + __asm__( "lcall (%%edi)\n\t" "jc 1f\n\t" "xor %%ah, %%ah\n" @@ -555,7 +503,7 @@ : "1" (PCIBIOS_PCI_BIOS_PRESENT), "D" (&pci_indirect) : "memory"); - restore_flags(flags); + __restore_flags(flags); status = (eax >> 8) & 0xff; hw_mech = eax & 0xff; @@ -589,9 +537,7 @@ { unsigned long bx; unsigned long ret; - unsigned long flags; - save_flags(flags); cli(); __asm__ ("lcall (%%edi)\n\t" "jc 1f\n\t" "xor %%ah, %%ah\n" @@ -602,7 +548,6 @@ "c" (class_code), "S" ((int) index), "D" (&pci_indirect)); - restore_flags(flags); *bus = (bx >> 8) & 0xff; *device_fn = bx & 0xff; return (int) (ret & 0xff00) >> 8; @@ -615,9 +560,7 @@ { unsigned short bx; unsigned short ret; - unsigned long flags; - save_flags(flags); cli(); __asm__("lcall (%%edi)\n\t" "jc 1f\n\t" "xor %%ah, %%ah\n" @@ -629,7 +572,6 @@ "d" (vendor), "S" ((int) index), "D" (&pci_indirect)); - restore_flags(flags); *bus = (bx >> 8) & 0xff; *device_fn = bx & 0xff; return (int) (ret & 0xff00) >> 8; @@ -640,9 +582,7 @@ { unsigned long ret; unsigned long bx = (bus << 8) | device_fn; - unsigned long flags; - save_flags(flags); cli(); __asm__("lcall (%%esi)\n\t" "jc 1f\n\t" "xor %%ah, %%ah\n" @@ -653,7 +593,6 @@ "b" (bx), "D" ((long) where), "S" (&pci_indirect)); - restore_flags(flags); return (int) (ret & 0xff00) >> 8; } @@ -662,9 +601,7 @@ { unsigned long ret; unsigned long bx = (bus << 8) | device_fn; - unsigned long flags; - save_flags(flags); cli(); __asm__("lcall (%%esi)\n\t" "jc 1f\n\t" "xor %%ah, %%ah\n" @@ -675,7 +612,6 @@ "b" (bx), "D" ((long) where), "S" (&pci_indirect)); - restore_flags(flags); return (int) (ret & 0xff00) >> 8; } @@ -684,9 +620,7 @@ { unsigned long ret; unsigned long bx = (bus << 8) | device_fn; - unsigned long flags; - save_flags(flags); cli(); __asm__("lcall (%%esi)\n\t" "jc 1f\n\t" "xor %%ah, %%ah\n" @@ -697,7 +631,6 @@ "b" (bx), "D" ((long) where), "S" (&pci_indirect)); - restore_flags(flags); return (int) (ret & 0xff00) >> 8; } @@ -706,9 +639,7 @@ { unsigned long ret; unsigned long bx = (bus << 8) | device_fn; - unsigned long flags; - save_flags(flags); cli(); __asm__("lcall (%%esi)\n\t" "jc 1f\n\t" "xor %%ah, %%ah\n" @@ -719,7 +650,6 @@ "b" (bx), "D" ((long) where), "S" (&pci_indirect)); - restore_flags(flags); return (int) (ret & 0xff00) >> 8; } @@ -728,9 +658,7 @@ { unsigned long ret; unsigned long bx = (bus << 8) | device_fn; - unsigned long flags; - save_flags(flags); cli(); __asm__("lcall (%%esi)\n\t" "jc 1f\n\t" "xor %%ah, %%ah\n" @@ -741,7 +669,6 @@ "b" (bx), "D" ((long) where), "S" (&pci_indirect)); - restore_flags(flags); return (int) (ret & 0xff00) >> 8; } @@ -750,9 +677,7 @@ { unsigned long ret; unsigned long bx = (bus << 8) | device_fn; - unsigned long flags; - save_flags(flags); cli(); __asm__("lcall (%%esi)\n\t" "jc 1f\n\t" "xor %%ah, %%ah\n" @@ -763,7 +688,6 @@ "b" (bx), "D" ((long) where), "S" (&pci_indirect)); - restore_flags(flags); return (int) (ret & 0xff00) >> 8; } @@ -860,8 +784,14 @@ break; } } - if (!d) + if (!d) { printk("PCI: BIOS reporting unknown device %02x:%02x\n", bus, devfn); + /* + * We must not continue scanning as several buggy BIOSes + * return garbage after the last device. Grr. + */ + break; + } } if (!idx) { printk("PCI: Device %02x:%02x not found by BIOS\n",
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