From: Andi Kleen Date: Tue, 26 Sep 2006 08:52:41 +0000 (+0200) Subject: [PATCH] x86: Allow disabling early pci scans with pci=noearly or disallowing conf1 X-Git-Tag: v2.6.19-rc1~1077^2~7 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0637a70a5db98182d9ad3d6ae1ee30acf20afde9;p=linux-2.6 [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 Signed-off-by: Andi Kleen --- diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 71d05f4817..4ae99f6e99 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1240,7 +1240,11 @@ running once the system is up. bootloader. This is currently used on IXP2000 systems where the bus has to be configured a certain way for adjunct CPUs. - + noearly [X86] Don't do any early type 1 scanning. + This might help on some broken boards which + machine check when some devices' config space + is read. But various workarounds are disabled + and some IOMMU drivers will not work. pcmv= [HW,PCMCIA] BadgePAD 4 pd. [PARIDE] diff --git a/arch/i386/kernel/acpi/earlyquirk.c b/arch/i386/kernel/acpi/earlyquirk.c index 1649a175a2..fe799b11ac 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 0a362e3aea..68bce194e6 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 b1f7f40d80..713d6c866c 100644 --- a/arch/i386/pci/early.c +++ b/arch/i386/pci/early.c @@ -1,6 +1,8 @@ #include +#include #include #include +#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 8a7cf1f236..1814f74569 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 diff --git a/arch/x86_64/kernel/aperture.c b/arch/x86_64/kernel/aperture.c index f851e1f9c8..b487396c4c 100644 --- a/arch/x86_64/kernel/aperture.c +++ b/arch/x86_64/kernel/aperture.c @@ -212,7 +212,7 @@ void __init iommu_hole_init(void) u64 aper_base, last_aper_base = 0; int valid_agp = 0; - if (iommu_aperture_disabled || !fix_aperture) + if (iommu_aperture_disabled || !fix_aperture || !early_pci_allowed()) return; printk("Checking aperture...\n"); diff --git a/arch/x86_64/kernel/early-quirks.c b/arch/x86_64/kernel/early-quirks.c index d637cff1c4..208e38a372 100644 --- a/arch/x86_64/kernel/early-quirks.c +++ b/arch/x86_64/kernel/early-quirks.c @@ -82,6 +82,10 @@ static struct chipset early_qrk[] = { void __init early_quirks(void) { int num, slot, func; + + if (!early_pci_allowed()) + return; + /* Poor man's PCI discovery */ for (num = 0; num < 32; num++) { for (slot = 0; slot < 32; slot++) { diff --git a/arch/x86_64/kernel/pci-calgary.c b/arch/x86_64/kernel/pci-calgary.c index 466588f956..cfb09b07ae 100644 --- a/arch/x86_64/kernel/pci-calgary.c +++ b/arch/x86_64/kernel/pci-calgary.c @@ -924,6 +924,9 @@ void __init detect_calgary(void) if (swiotlb || no_iommu || iommu_detected) return; + if (!early_pci_allowed()) + return; + specified_table_size = determine_tce_table_size(end_pfn * PAGE_SIZE); for (bus = 0; bus < MAX_PHB_BUS_NUM; bus++) { diff --git a/arch/x86_64/kernel/vsmp.c b/arch/x86_64/kernel/vsmp.c index 92f70c7496..044e852bd2 100644 --- a/arch/x86_64/kernel/vsmp.c +++ b/arch/x86_64/kernel/vsmp.c @@ -20,6 +20,9 @@ static int __init vsmp_init(void) void *address; unsigned int cap, ctl; + if (!early_pci_allowed()) + return 0; + /* Check if we are running on a ScaleMP vSMP box */ if ((read_pci_config_16(0, 0x1f, 0, PCI_VENDOR_ID) != PCI_VENDOR_ID_SCALEMP) || (read_pci_config_16(0, 0x1f, 0, PCI_DEVICE_ID) != PCI_DEVICE_ID_SCALEMP_VSMP_CTL)) diff --git a/arch/x86_64/mm/k8topology.c b/arch/x86_64/mm/k8topology.c index 7c45c2d2b8..5cf594f923 100644 --- a/arch/x86_64/mm/k8topology.c +++ b/arch/x86_64/mm/k8topology.c @@ -54,6 +54,9 @@ int __init k8_scan_nodes(unsigned long start, unsigned long end) nodes_clear(nodes_parsed); + if (!early_pci_allowed()) + return -1; + nb = find_northbridge(); if (nb < 0) return nb; diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 9f79dd6d51..684deb6b03 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -953,13 +953,12 @@ static int __devinit pci_setup(char *str) } str = k; } - return 1; + return 0; } +early_param("pci", pci_setup); device_initcall(pci_init); -__setup("pci=", pci_setup); - #if defined(CONFIG_ISA) || defined(CONFIG_EISA) /* FIXME: Some boxes have multiple ISA bridges! */ struct pci_dev *isa_bridge; diff --git a/include/asm-x86_64/pci-direct.h b/include/asm-x86_64/pci-direct.h index 9d916cdaa1..eba9cb471d 100644 --- a/include/asm-x86_64/pci-direct.h +++ b/include/asm-x86_64/pci-direct.h @@ -11,4 +11,6 @@ extern u8 read_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset); extern u16 read_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset); extern void write_pci_config(u8 bus, u8 slot, u8 func, u8 offset, u32 val); +extern int early_pci_allowed(void); + #endif