Commit 2e0ad0e2 authored Jun 09, 2014 by Jiang Liu Committed by Thomas Gleixner Jun 21, 2014

x86, ACPI, irq: Fix possible eror in GSI to IRQ mapping for legacy IRQ



A default identity mapping between GSI and IRQ is built for legacy IRQs.
So when overriding the default identity mapping for legacy IRQs,
we should also invalidate isa_irq_to_gsi[gsi] when setting
isa_irq_to_gsi[irq] = gsi.  Otherwise there may be two entries with the
same GSI in the isa_irq_to_gsi array, and acpi_isa_irq_to_gsi() may give
wrong result.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Link: http://lkml.kernel.org/r/1402302011-23642-10-git-send-email-jiang.liu@linux.intel.com


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

parent 2c0a6894

arch/x86/kernel/acpi/boot.c

+9 −1

Original line number	Diff line number	Diff line
		@@ -366,6 +366,13 @@ static void __init mp_override_legacy_irq(u8 bus_irq, u8 polarity, u8 trigger,

		mp_save_irq(&mp_irq);

		/*
		* Reset default identity mapping if gsi is also an legacy IRQ,
		* otherwise there will be more than one entry with the same GSI
		* and acpi_isa_irq_to_gsi() may give wrong result.
		*/
		if (gsi < NR_IRQS_LEGACY && isa_irq_to_gsi[gsi] == gsi)
		isa_irq_to_gsi[gsi] = ACPI_INVALID_GSI;
		isa_irq_to_gsi[bus_irq] = gsi;
		}

		@@ -621,7 +628,8 @@ EXPORT_SYMBOL_GPL(acpi_gsi_to_irq);

		int acpi_isa_irq_to_gsi(unsigned isa_irq, u32 *gsi)
		{
		if (isa_irq < NR_IRQS_LEGACY) {
		if (isa_irq < NR_IRQS_LEGACY &&
		isa_irq_to_gsi[isa_irq] != ACPI_INVALID_GSI) {
		*gsi = isa_irq_to_gsi[isa_irq];
		return 0;
		}