[PATCH 37 of 38] xen: bind pirq to vector and event channel

From: Jeremy Fitzhardinge
Date: Thu Nov 13 2008 - 14:46:38 EST


Having converting a dev+pin to a gsi, and that gsi to an irq, and
allocated a vector for the irq, we must program the IO APIC to deliver
an interrupt on a pin to the vector, so Xen can deliver it as an event
channel.

Given the pirq, we can get the gsi and vector. We map the gsi to a
specific IO APIC's pin, and set the routing entry.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
---
arch/x86/xen/apic.c | 4 ++--
arch/x86/xen/pci.c | 34 +++++++++++++++++++++++++++++++---
2 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/arch/x86/xen/apic.c b/arch/x86/xen/apic.c
--- a/arch/x86/xen/apic.c
+++ b/arch/x86/xen/apic.c
@@ -4,6 +4,7 @@

#include <asm/io_apic.h>
#include <asm/acpi.h>
+#include <asm/hw_irq.h>

#include <asm/xen/hypervisor.h>
#include <asm/xen/hypercall.h>
@@ -13,8 +14,7 @@

static void __init xen_io_apic_init(void)
{
- printk("xen apic init\n");
- dump_stack();
+ enable_IO_APIC();
}

static unsigned int xen_io_apic_read(unsigned apic, unsigned reg)
diff --git a/arch/x86/xen/pci.c b/arch/x86/xen/pci.c
--- a/arch/x86/xen/pci.c
+++ b/arch/x86/xen/pci.c
@@ -2,8 +2,10 @@
#include <linux/acpi.h>
#include <linux/pci.h>

+#include <asm/mpspec.h>
+#include <asm/io_apic.h>
+
#include <asm/xen/hypervisor.h>
-
#include <xen/interface/xen.h>
#include <xen/events.h>

@@ -11,6 +13,31 @@

#include "xen-ops.h"

+static void xen_set_io_apic_routing(int irq, int trigger, int polarity)
+{
+ int ioapic, ioapic_pin;
+ int vector, gsi;
+ struct IO_APIC_route_entry entry;
+
+ gsi = xen_gsi_from_irq(irq);
+ vector = xen_vector_from_irq(irq);
+
+ ioapic = mp_find_ioapic(gsi);
+ if (ioapic == -1) {
+ printk(KERN_WARNING "xen_set_ioapic_routing: irq %d gsi %d ioapic %d\n",
+ irq, gsi, ioapic);
+ return;
+ }
+
+ ioapic_pin = mp_find_ioapic_pin(ioapic, gsi);
+
+ printk(KERN_INFO "xen_set_ioapic_routing: irq %d gsi %d vector %d ioapic %d pin %d triggering %d polarity %d\n",
+ irq, gsi, vector, ioapic, ioapic_pin, trigger, polarity);
+
+ setup_ioapic_entry(ioapic, -1, &entry, ~0, trigger, polarity, vector);
+ ioapic_write_entry(ioapic, ioapic_pin, entry);
+}
+
int xen_register_gsi(u32 gsi, int triggering, int polarity)
{
int irq;
@@ -25,6 +52,9 @@

printk(KERN_DEBUG "xen: --> irq=%d\n", irq);

+ if (irq > 0)
+ xen_set_io_apic_routing(irq, triggering, polarity);
+
return irq;
}

@@ -45,8 +75,6 @@

printk(KERN_INFO "xen: PCI device %s pin %d -> irq %d\n",
pci_name(dev), dev->pin, irq);
-
- /* install vector in ioapic? */
} else
printk(KERN_INFO "xen: irq enable for %s failed: rc=%d pin=%d irq=%d\n",
pci_name(dev), rc, dev->pin, dev->irq);


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