Commit 6a1caa21 authored Jul 30, 2005 by Natalie.Protasevich@unisys.com Committed by Linus Torvalds Jul 30, 2005

[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 <Natalie.Protasevich@unisys.com>
Acked-by: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

parent c70f5d66

arch/x86_64/kernel/mpparse.c

+15 −2

Original line number	Diff line number	Diff line
		@@ -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;
		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,

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