From 6a1caa21d66bcb9ba9892435a0a54fc32cd9eeab Mon Sep 17 00:00:00 2001 From: "Natalie.Protasevich@unisys.com" Date: Sat, 30 Jul 2005 11:25:32 -0700 Subject: [PATCH] [PATCH] x86_64: avoid wasting IRQs patch update The patch adds boundary check for the MAX_GSI_NUM. Same as the update for i386, the patch addresses a problem with ACPI SCI IRQ. The patch corrects the code such that SCI IRQ is skipped and duplicate entry is avoided. The VIA chipset uses 4-bit IRQ register for internal interrupt routing, and therefore cannot handle IRQ numbers assigned to its devices. The patch corrects this problem by allowing PCI IRQs below 16. Signed-off-by: Natalie Protasevich Acked-by: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86_64/kernel/mpparse.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/arch/x86_64/kernel/mpparse.c b/arch/x86_64/kernel/mpparse.c index 08abf9f5b159..79c362d03e2e 100644 --- a/arch/x86_64/kernel/mpparse.c +++ b/arch/x86_64/kernel/mpparse.c @@ -970,8 +970,21 @@ int mp_register_gsi(u32 gsi, int edge_level, int active_high_low) * due to unused I/O APIC pins. */ int irq = gsi; - gsi = pci_irq++; - gsi_to_irq[irq] = gsi; + if (gsi < MAX_GSI_NUM) { + if (gsi > 15) + gsi = pci_irq++; +#ifdef CONFIG_ACPI_BUS + /* + * Don't assign IRQ used by ACPI SCI + */ + if (gsi == acpi_fadt.sci_int) + gsi = pci_irq++; +#endif + gsi_to_irq[irq] = gsi; + } else { + printk(KERN_ERR "GSI %u is too high\n", gsi); + return gsi; + } } io_apic_set_pci_routing(ioapic, ioapic_pin, gsi, -- 2.20.1