diff options
| author | Andi Kleen <ak@suse.de> | 2006-09-26 10:52:41 +0200 |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2006-09-26 10:52:41 +0200 |
| commit | 0637a70a5db98182d9ad3d6ae1ee30acf20afde9 (patch) | |
| tree | 36b625e24f3fe11a97cd9926ca2be6b2df1cbf89 /arch/i386 | |
| parent | 8f60774a116ced9b73ae3913d511687889efe725 (diff) | |
[PATCH] x86: Allow disabling early pci scans with pci=noearly or disallowing conf1
Some buggy systems can machine check when config space accesses
happen for some non existent devices. i386/x86-64 do some early
device scans that might trigger this. Allow pci=noearly to disable
this. Also when type 1 is disabling also don't do any early
accesses which are always type1.
This moves the pci= configuration parsing to be a early parameter.
I don't think this can break anything because it only changes
a single global that is only used by PCI.
Cc: gregkh@suse.de
Cc: Trammell Hudson <hudson@osresearch.net>
Signed-off-by: Andi Kleen <ak@suse.de>
Diffstat (limited to 'arch/i386')
| -rw-r--r-- | arch/i386/kernel/acpi/earlyquirk.c | 6 | ||||
| -rw-r--r-- | arch/i386/pci/common.c | 4 | ||||
| -rw-r--r-- | arch/i386/pci/early.c | 8 | ||||
| -rw-r--r-- | arch/i386/pci/pci.h | 1 |
4 files changed, 18 insertions, 1 deletions
diff --git a/arch/i386/kernel/acpi/earlyquirk.c b/arch/i386/kernel/acpi/earlyquirk.c index 1649a175a206..fe799b11ac0a 100644 --- a/arch/i386/kernel/acpi/earlyquirk.c +++ b/arch/i386/kernel/acpi/earlyquirk.c @@ -48,7 +48,11 @@ void __init check_acpi_pci(void) int num, slot, func; /* Assume the machine supports type 1. If not it will - always read ffffffff and should not have any side effect. */ + always read ffffffff and should not have any side effect. + Actually a few buggy systems can machine check. Allow the user + to disable it by command line option at least -AK */ + if (!early_pci_allowed()) + return; /* Poor man's PCI discovery */ for (num = 0; num < 32; num++) { diff --git a/arch/i386/pci/common.c b/arch/i386/pci/common.c index 0a362e3aeac5..68bce194e688 100644 --- a/arch/i386/pci/common.c +++ b/arch/i386/pci/common.c @@ -242,6 +242,10 @@ char * __devinit pcibios_setup(char *str) acpi_noirq_set(); return NULL; } + else if (!strcmp(str, "noearly")) { + pci_probe |= PCI_PROBE_NOEARLY; + return NULL; + } #ifndef CONFIG_X86_VISWS else if (!strcmp(str, "usepirqmask")) { pci_probe |= PCI_USE_PIRQ_MASK; diff --git a/arch/i386/pci/early.c b/arch/i386/pci/early.c index b1f7f40d809b..713d6c866cae 100644 --- a/arch/i386/pci/early.c +++ b/arch/i386/pci/early.c @@ -1,6 +1,8 @@ #include <linux/kernel.h> +#include <linux/pci.h> #include <asm/pci-direct.h> #include <asm/io.h> +#include "pci.h" /* Direct PCI access. This is used for PCI accesses in early boot before the PCI subsystem works. */ @@ -42,3 +44,9 @@ void write_pci_config(u8 bus, u8 slot, u8 func, u8 offset, outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8); outl(val, 0xcfc); } + +int early_pci_allowed(void) +{ + return (pci_probe & (PCI_PROBE_CONF1|PCI_PROBE_NOEARLY)) == + PCI_PROBE_CONF1; +} diff --git a/arch/i386/pci/pci.h b/arch/i386/pci/pci.h index 8a7cf1f23684..1814f74569c6 100644 --- a/arch/i386/pci/pci.h +++ b/arch/i386/pci/pci.h @@ -17,6 +17,7 @@ #define PCI_PROBE_CONF2 0x0004 #define PCI_PROBE_MMCONF 0x0008 #define PCI_PROBE_MASK 0x000f +#define PCI_PROBE_NOEARLY 0x0010 #define PCI_NO_SORT 0x0100 #define PCI_BIOS_SORT 0x0200 |