On 2016/3/30 0:35, Julien Grall wrote:

Hi Shannon,

On 24/03/16 14:44, Shannon Zhao wrote:

quoted

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

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

So I would say: ", the kernel will get the event-channel..."

quoted

HVM_PARAM_CALLBACK_IRQ.

Signed-off-by: Shannon Zhao <redacted>
Reviewed-by: Stefano Stabellini <redacted>
---
  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..680aae0 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;
+    xen_events_irq = 0;
+
+    if (!HYPERVISOR_hvm_op(HVMOP_get_param, &a)) {
+        if ((a.value >> 56) == HVM_PARAM_CALLBACK_TYPE_PPI) {
+            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);
+        }
+    }

Can you invert the condition to remove one layer of indentation?

Sure, will update.

Thanks,
-- 
Shannon