Commit ee339fe6 authored by Konrad Rzeszutek Wilk's avatar Konrad Rzeszutek Wilk
Browse files

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: default avatarRaghavendra D Prabhu <rprabhu@wnohang.net>
Tested-by: default avatarRaghavendra D Prabhu <rprabhu@wnohang.net>
[http://lists.xensource.com/archives/html/xen-devel/2011-07/msg00154.html

]
Suggested-by: default avatarIan Campbell <ijc@hellion.org.uk>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent 155a16f2

arch/x86/pci/xen.c

+28 −28
Original line number Diff line number Diff line
@@ -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);

	}

}

CRA Git | Maintained and supported by SUSTech CRA and CCSE