[Xen-devel] [PATCH 07/10] xen/acpi: Prepare for cpu hotplug

["Liu, Jinsong" <jinsong.liu@xxxxxxxxx>]

>From 0dad15c02d033d6be7e9447fbe5f645d97badc24 Mon Sep 17 00:00:00 2001
From: Liu Jinsong <jinsong.liu@xxxxxxxxx>
Date: Tue, 13 Dec 2011 21:14:45 +0800
Subject: [PATCH 07/10] xen/acpi: Prepare for cpu hotplug

This patch rebased from Jeremy's pvops commit
68320323a51c2378aca433c76157d9e66104ff1e

It does some prepare work for cpu hotplug

Signed-off-by: Liu, Jinsong <jinsong.liu@xxxxxxxxx>
Signed-off-by: Jiang, Yunhong <yunhong.jiang@xxxxxxxxx>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
---
 drivers/acpi/processor_xen.c |   37 +++++++++++++++++++++++++++++++++++++
 1 files changed, 37 insertions(+), 0 deletions(-)

diff --git a/drivers/acpi/processor_xen.c b/drivers/acpi/processor_xen.c
index 029e10c..38a1c05 100644
--- a/drivers/acpi/processor_xen.c
+++ b/drivers/acpi/processor_xen.c
@@ -19,6 +19,7 @@
 #include <acpi/acpi_drivers.h>
 #include <acpi/processor.h>
 #include <xen/acpi.h>
+#include <xen/pcpu.h>
 
 #define PREFIX "ACPI: "
 
@@ -54,6 +55,42 @@ struct acpi_driver xen_acpi_processor_driver = {
                },
 };
 
+static int is_processor_present(acpi_handle handle)
+{
+       acpi_status status;
+       unsigned long long sta = 0;
+
+
+       status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
+
+       if (ACPI_SUCCESS(status) && (sta & ACPI_STA_DEVICE_PRESENT))
+               return 1;
+
+       /*
+        * _STA is mandatory for a processor that supports hot plug
+        */
+       if (status == AE_NOT_FOUND)
+               ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+                               "Processor does not support hot plug\n"));
+       else
+               ACPI_EXCEPTION((AE_INFO, status,
+                               "Processor Device is not present"));
+       return 0;
+}
+
+static acpi_status
+xen_acpi_processor_hotadd_init(struct acpi_processor *pr, int *p_cpu)
+{
+       if (!is_processor_present(pr->handle))
+               return AE_ERROR;
+
+       if (processor_cntl_xen_notify(pr,
+                               PROCESSOR_HOTPLUG, HOTPLUG_TYPE_ADD))
+               return AE_ERROR;
+
+       return AE_OK;
+}
+
 #ifdef CONFIG_CPU_FREQ
 /*
  * Existing ACPI module does parse performance states at some point,
-- 
1.6.5.6

Attachment: 0007-xen-acpi-Prepare-for-cpu-hotplug.patch
Description: 0007-xen-acpi-Prepare-for-cpu-hotplug.patch

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