[PATCH v3 10/17] arm/xen: Get event-channel irq through HVM_PARAM when booting with ACPI

From: Shannon Zhao
Date: Fri Jan 22 2016 - 22:25:00 EST


From: Shannon Zhao <shannon.zhao@xxxxxxxxxx>

When booting with ACPI, it could get the event-channel irq through
HVM_PARAM_CALLBACK_IRQ.

Signed-off-by: Shannon Zhao <shannon.zhao@xxxxxxxxxx>
---
arch/arm/xen/enlighten.c | 36 +++++++++++++++++++++++++++++++++++-
1 file changed, 35 insertions(+), 1 deletion(-)

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 6d90a62..0e010bb 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -29,6 +29,7 @@
#include <linux/time64.h>
#include <linux/timekeeping.h>
#include <linux/timekeeper_internal.h>
+#include <linux/acpi.h>

#include <linux/mm.h>

@@ -262,6 +263,35 @@ void __init xen_early_init(void)
add_preferred_console("hvc", 0, NULL);
}

+static void __init xen_acpi_guest_init_events_irq(void)
+{
+#ifdef CONFIG_ACPI
+ struct xen_hvm_param a;
+ int interrupt, trigger, polarity;
+
+ a.domid = DOMID_SELF;
+ a.index = HVM_PARAM_CALLBACK_IRQ;
+ xen_events_irq = 0;
+
+ if (!HYPERVISOR_hvm_op(HVMOP_get_param, &a)) {
+ if ((a.value >> 56) == HVM_PARAM_CALLBACK_TYPE_EVENT) {
+ interrupt = a.value & 0xff;
+ trigger = ((a.value >> 8) & 0x1) ? ACPI_EDGE_SENSITIVE
+ : ACPI_LEVEL_SENSITIVE;
+ polarity = ((a.value >> 8) & 0x2) ? ACPI_ACTIVE_LOW
+ : ACPI_ACTIVE_HIGH;
+ xen_events_irq = acpi_register_gsi(NULL, interrupt,
+ trigger, polarity);
+ }
+ }
+#endif
+}
+
+static void __init xen_dt_guest_init_events_irq(void)
+{
+ xen_events_irq = irq_of_parse_and_map(xen_node, 0);
+}
+
static int __init xen_guest_init(void)
{
struct xen_add_to_physmap xatp;
@@ -270,7 +300,11 @@ static int __init xen_guest_init(void)
if (!xen_domain())
return 0;

- xen_events_irq = irq_of_parse_and_map(xen_node, 0);
+ if (!acpi_disabled)
+ xen_acpi_guest_init_events_irq();
+ else
+ xen_dt_guest_init_events_irq();
+
if (!xen_events_irq) {
pr_err("Xen event channel interrupt not found\n");
return -ENODEV;
--
2.0.4