Impact: program IO APICs under Xen
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.
(We were passing the ACPI triggering and polarity levels directly into
the apic - but they have reversed values. The result was that
all the level-triggered interrupts were edge, and vice-versa.
It's surprising that anything worked at all, but now AHCI works
for me.
Thanks for Gerd Hoffmann for noticing this.)
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
---
arch/x86/xen/apic.c | 4 ++--
arch/x86/xen/pci.c | 32 ++++++++++++++++++++++++++++++++
2 files changed, 34 insertions(+), 2 deletions(-)
diff --git a/arch/x86/xen/apic.c b/arch/x86/xen/apic.c
index 17736a0..e9d9ea7 100644
--- 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 @@
void __init xen_io_apic_init(void)
{
- printk("xen apic init\n");
- dump_stack();
+ enable_IO_APIC();
}
unsigned int xen_io_apic_read(unsigned apic, unsigned reg)
diff --git a/arch/x86/xen/pci.c b/arch/x86/xen/pci.c
index f450007..0f3663c 100644
--- a/arch/x86/xen/pci.c
+++ b/arch/x86/xen/pci.c
@@ -2,6 +2,8 @@
#include <linux/acpi.h>
#include <linux/pci.h>
+#include <asm/mpspec.h>
+#include <asm/io_apic.h>
#include <asm/pci_x86.h>
#include <asm/xen/hypervisor.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 +52,11 @@ int xen_register_gsi(u32 gsi, int triggering, int polarity)
printk(KERN_DEBUG "xen: --> irq=%d\n", irq);
+ if (irq > 0)
+ xen_set_io_apic_routing(irq,
+ triggering == ACPI_EDGE_SENSITIVE ? 0 :
1,
+ polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
+
return irq;
}
--
1.6.0.6
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