From ee339fe63ac408e4604c1c88b1f9a428f2511b70 Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Wed, 6 Jul 2011 09:43:16 -0400 Subject: xen/pci: Move check for acpi_sci_override_gsi to xen_setup_acpi_sci. Previously we would check for acpi_sci_override_gsi == gsi every time a PCI device was enabled. That works during early bootup, but later on it could lead to triggering unnecessarily the acpi_gsi_to_irq(..) lookup. The reason is that acpi_sci_override_gsi was declared in __initdata and after early bootup could contain bogus values. This patch moves the check for acpi_sci_override_gsi to the site where the ACPI SCI is preset. CC: stable@kernel.org Reported-by: Raghavendra D Prabhu Tested-by: Raghavendra D Prabhu [http://lists.xensource.com/archives/html/xen-devel/2011-07/msg00154.html] Suggested-by: Ian Campbell Signed-off-by: Konrad Rzeszutek Wilk --- arch/x86/pci/xen.c | 56 +++++++++++++++++++++++++++--------------------------- 1 file changed, 28 insertions(+), 28 deletions(-) (limited to 'arch/x86/pci/xen.c') diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c index fe008309ffec..f567965c0620 100644 --- a/arch/x86/pci/xen.c +++ b/arch/x86/pci/xen.c @@ -327,13 +327,12 @@ int __init pci_xen_hvm_init(void) } #ifdef CONFIG_XEN_DOM0 -static int xen_register_pirq(u32 gsi, int triggering) +static int xen_register_pirq(u32 gsi, int gsi_override, int triggering) { int rc, pirq, irq = -1; struct physdev_map_pirq map_irq; int shareable = 0; char *name; - bool gsi_override = false; if (!xen_pv_domain()) return -1; @@ -345,31 +344,12 @@ static int xen_register_pirq(u32 gsi, int triggering) shareable = 1; name = "ioapic-level"; } - pirq = xen_allocate_pirq_gsi(gsi); if (pirq < 0) goto out; - /* Before we bind the GSI to a Linux IRQ, check whether - * we need to override it with bus_irq (IRQ) value. Usually for - * IRQs below IRQ_LEGACY_IRQ this holds IRQ == GSI, as so: - * ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 low level) - * but there are oddballs where the IRQ != GSI: - * ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 20 low level) - * which ends up being: gsi_to_irq[9] == 20 - * (which is what acpi_gsi_to_irq ends up calling when starting the - * the ACPI interpreter and keels over since IRQ 9 has not been - * setup as we had setup IRQ 20 for it). - */ - if (gsi == acpi_sci_override_gsi) { - /* Check whether the GSI != IRQ */ - acpi_gsi_to_irq(gsi, &irq); - if (irq != gsi) - /* Bugger, we MUST have that IRQ. */ - gsi_override = true; - } - if (gsi_override) - irq = xen_bind_pirq_gsi_to_irq(irq, pirq, shareable, name); + if (gsi_override >= 0) + irq = xen_bind_pirq_gsi_to_irq(gsi_override, pirq, shareable, name); else irq = xen_bind_pirq_gsi_to_irq(gsi, pirq, shareable, name); if (irq < 0) @@ -392,7 +372,7 @@ out: return irq; } -static int xen_register_gsi(u32 gsi, int triggering, int polarity) +static int xen_register_gsi(u32 gsi, int gsi_override, int triggering, int polarity) { int rc, irq; struct physdev_setup_gsi setup_gsi; @@ -403,7 +383,7 @@ static int xen_register_gsi(u32 gsi, int triggering, int polarity) printk(KERN_DEBUG "xen: registering gsi %u triggering %d polarity %d\n", gsi, triggering, polarity); - irq = xen_register_pirq(gsi, triggering); + irq = xen_register_pirq(gsi, gsi_override, triggering); setup_gsi.gsi = gsi; setup_gsi.triggering = (triggering == ACPI_EDGE_SENSITIVE ? 0 : 1); @@ -425,6 +405,8 @@ static __init void xen_setup_acpi_sci(void) int rc; int trigger, polarity; int gsi = acpi_sci_override_gsi; + int irq = -1; + int gsi_override = -1; if (!gsi) return; @@ -441,7 +423,25 @@ static __init void xen_setup_acpi_sci(void) printk(KERN_INFO "xen: sci override: global_irq=%d trigger=%d " "polarity=%d\n", gsi, trigger, polarity); - gsi = xen_register_gsi(gsi, trigger, polarity); + /* Before we bind the GSI to a Linux IRQ, check whether + * we need to override it with bus_irq (IRQ) value. Usually for + * IRQs below IRQ_LEGACY_IRQ this holds IRQ == GSI, as so: + * ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 low level) + * but there are oddballs where the IRQ != GSI: + * ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 20 low level) + * which ends up being: gsi_to_irq[9] == 20 + * (which is what acpi_gsi_to_irq ends up calling when starting the + * the ACPI interpreter and keels over since IRQ 9 has not been + * setup as we had setup IRQ 20 for it). + */ + /* Check whether the GSI != IRQ */ + if (acpi_gsi_to_irq(gsi, &irq) == 0) { + if (irq >= 0 && irq != gsi) + /* Bugger, we MUST have that IRQ. */ + gsi_override = irq; + } + + gsi = xen_register_gsi(gsi, gsi_override, trigger, polarity); printk(KERN_INFO "xen: acpi sci %d\n", gsi); return; @@ -450,7 +450,7 @@ static __init void xen_setup_acpi_sci(void) static int acpi_register_gsi_xen(struct device *dev, u32 gsi, int trigger, int polarity) { - return xen_register_gsi(gsi, trigger, polarity); + return xen_register_gsi(gsi, -1 /* no GSI override */, trigger, polarity); } static int __init pci_xen_initial_domain(void) @@ -489,7 +489,7 @@ void __init xen_setup_pirqs(void) if (acpi_get_override_irq(irq, &trigger, &polarity) == -1) continue; - xen_register_pirq(irq, + xen_register_pirq(irq, -1 /* no GSI override */, trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE); } } -- cgit v1.2.1