[PATCH v11 10/17] arm/xen: Get event-channel irq through HVM_PARAM when booting with ACPI

[Shannon Zhao]

From: Shannon Zhao <shannon.z...@linaro.org>

The kernel will get the event-channel IRQ through
HVM_PARAM_CALLBACK_IRQ.

Signed-off-by: Shannon Zhao <shannon.z...@linaro.org>
Reviewed-by: Stefano Stabellini <stefano.stabell...@eu.citrix.com>
Reviewed-by: Julien Grall <julien.gr...@arm.com>
---
 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 d94f726..06bd61a 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -30,6 +30,7 @@
 #include <linux/time64.h>
 #include <linux/timekeeping.h>
 #include <linux/timekeeper_internal.h>
+#include <linux/acpi.h>
 
 #include <linux/mm.h>
 
@@ -278,6 +279,35 @@ void __init xen_early_init(void)
                add_preferred_console("hvc", 0, NULL);
 }
 
+static void __init xen_acpi_guest_init(void)
+{
+#ifdef CONFIG_ACPI
+       struct xen_hvm_param a;
+       int interrupt, trigger, polarity;
+
+       a.domid = DOMID_SELF;
+       a.index = HVM_PARAM_CALLBACK_IRQ;
+
+       if (HYPERVISOR_hvm_op(HVMOP_get_param, &a)
+           || (a.value >> 56) != HVM_PARAM_CALLBACK_TYPE_PPI) {
+               xen_events_irq = 0;
+               return;
+       }
+
+       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(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;
@@ -286,7 +316,11 @@ 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();
+       else
+               xen_dt_guest_init();
+
        if (!xen_events_irq) {
                pr_err("Xen event channel interrupt not found\n");
                return -ENODEV;
-- 
2.0.4