From 41b9eb264c8407655db57b60b4457fe1b2ec9977 Mon Sep 17 00:00:00 2001 From: Stefan Assmann Date: Tue, 15 Jul 2008 13:48:55 +0200 Subject: [PATCH] x86, pci: introduce config option for pci reroute quirks (was: [PATCH 0/3] Boot IRQ quirks for Broadcom and AMD/ATI) This is against linux-2.6-tip, branch pci-ioapic-boot-irq-quirks. From: Stefan Assmann Subject: Introduce config option for pci reroute quirks The config option X86_REROUTE_FOR_BROKEN_BOOT_IRQS is introduced to enable (or disable) the redirection of the interrupt handler to the boot interrupt line by default. Depending on the existence of interrupt masking / threaded interrupt handling in the kernel (vanilla, rt, ...) and the maturity of the rerouting patch, users can enable or disable the redirection by default. This means that the reroute quirk can be applied to any kernel without changing it. Interrupt sharing could be increased if this option is enabled. However this option is vital for threaded interrupt handling, as done by the RT kernel. It should simplify the consolidation with the RT kernel. The option can be overridden by either pci=ioapicreroute or pci=noioapicreroute. Signed-off-by: Stefan Assmann Signed-off-by: Olaf Dabrunz Cc: Jesse Barnes Cc: Jon Masters Cc: Ihno Krumreich Cc: Sven Dietrich Cc: Daniel Gollub Cc: Felix Foerster Signed-off-by: Ingo Molnar --- Documentation/kernel-parameters.txt | 4 ++++ arch/x86/Kconfig | 24 ++++++++++++++++++++++++ arch/x86/pci/common.c | 8 ++++++++ drivers/pci/quirks.c | 2 +- include/asm-x86/pci.h | 2 +- 5 files changed, 38 insertions(+), 2 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index f5662b7..62b6e80 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1536,6 +1536,10 @@ and is between 256 and 4096 characters. It is defined in the file primary IO-APIC for bridges that cannot disable boot IRQs. This fixes a source of spurious IRQs when the system masks IRQs. + noioapicreroute [APIC] Disable workaround that uses the + boot IRQ equivalent of an IRQ that connects to + a chipset where boot IRQs cannot be disabled. + The opposite of ioapicreroute. biosirq [X86-32] Use PCI BIOS calls to get the interrupt routing table. These calls are known to be buggy on several machines and they hang the machine diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 96e0c2e..0952133 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -665,6 +665,30 @@ config X86_VISWS_APIC def_bool y depends on X86_32 && X86_VISWS +config X86_REROUTE_FOR_BROKEN_BOOT_IRQS + bool "Reroute for broken boot IRQs" + default n + depends on X86_IO_APIC + help + This option enables a workaround that fixes a source of + spurious interrupts. This is recommended when threaded + interrupt handling is used on systems where the generation of + superfluous "boot interrupts" cannot be disabled. + + Some chipsets generate a legacy INTx "boot IRQ" when the IRQ + entry in the chipset's IO-APIC is masked (as, e.g. the RT + kernel does during interrupt handling). On chipsets where this + boot IRQ generation cannot be disabled, this workaround keeps + the original IRQ line masked so that only the equivalent "boot + IRQ" is delivered to the CPUs. The workaround also tells the + kernel to set up the IRQ handler on the boot IRQ line. In this + way only one interrupt is delivered to the kernel. Otherwise + the spurious second interrupt may cause the kernel to bring + down (vital) interrupt lines. + + Only affects "broken" chipsets. Interrupt sharing may be + increased on these systems. + config X86_MCE bool "Machine Check Exception" depends on !X86_VOYAGER diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c index 1485a26..bb1a01f 100644 --- a/arch/x86/pci/common.c +++ b/arch/x86/pci/common.c @@ -24,7 +24,11 @@ unsigned int pci_early_dump_regs; static int pci_bf_sort; int pci_routeirq; int noioapicquirk; +#ifdef CONFIG_X86_REROUTE_FOR_BROKEN_BOOT_IRQS +int noioapicreroute = 0; +#else int noioapicreroute = 1; +#endif int pcibios_last_bus = -1; unsigned long pirq_table_addr; struct pci_bus *pci_root_bus; @@ -528,6 +532,10 @@ char * __devinit pcibios_setup(char *str) if (noioapicreroute != -1) noioapicreroute = 0; return NULL; + } else if (!strcmp(str, "noioapicreroute")) { + if (noioapicreroute != -1) + noioapicreroute = 1; + return NULL; } return str; } diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 0911b0c..c880dd0 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -1397,7 +1397,7 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x260b, quirk_intel_pcie_pm); */ static void quirk_reroute_to_boot_interrupts_intel(struct pci_dev *dev) { - if (noioapicquirk) + if (noioapicquirk || noioapicreroute) return; dev->irq_reroute_variant = INTEL_IRQ_REROUTE_VARIANT; diff --git a/include/asm-x86/pci.h b/include/asm-x86/pci.h index 52a29f7..9584d6d 100644 --- a/include/asm-x86/pci.h +++ b/include/asm-x86/pci.h @@ -20,7 +20,7 @@ struct pci_sysdata { extern int pci_routeirq; extern int noioapicquirk; -extern int ioapicreroute; +extern int noioapicreroute; /* scan a bus after allocating a pci_sysdata for it */ extern struct pci_bus *pci_scan_bus_on_node(int busno, struct pci_ops *ops, -- 2.7.4