[PATCH v2 09/16] arm/xen: Get event-channel irq through HVM_PARAM when booting with ACPI

[Shannon Zhao]

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 | 30 +++++++++++++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 6d90a62..4e78c49 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>
 
@@ -270,7 +271,34 @@ 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) {
+#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) == 3) {
+				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
+	} else {
+		xen_events_irq = irq_of_parse_and_map(xen_node, 0);
+	}
+
 	if (!xen_events_irq) {
 		pr_err("Xen event channel interrupt not found\n");
 		return -ENODEV;
-- 
2.0.4