>From 7bdec2cce7de8fb41207238c61f3075220c70a55 Mon Sep 17 00:00:00 2001
From: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Date: Mon, 23 Feb 2009 00:06:06 -0800
Subject: [PATCH] xen: Enable ACPI sleep in Xen

Open CONFIG_ACPI_SLEEP in xenlinux, to enable ACPI based
power management. Basically, user can trigger power event
now by "echo *** > /sys/power/state". Also gear to pm
interface defined between xenlinux and Xen.

Also sync to xen interface headers consequently

[ From http://xenbits.xensource.com/linux-2.6.18-xen.hg
 change c68699484a65 ]

Signed-off-by Ke Yu <ke.yu@intel.com>
Signed-off-by Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c
index 7c243a2..a89de8d 100644
--- a/arch/x86/kernel/acpi/sleep.c
+++ b/arch/x86/kernel/acpi/sleep.c
@@ -12,6 +12,8 @@
 #include <asm/segment.h>
 #include <asm/desc.h>
 
+#include <asm/xen/hypervisor.h>
+
 #include "realmode/wakeup.h"
 #include "sleep.h"
 
@@ -37,6 +39,9 @@ int acpi_save_state_mem(void)
 {
 	struct wakeup_header *header;
 
+	if (xen_pv_domain())
+		return 0;	/* Xen will do this for us */
+
 	if (!acpi_realmode) {
 		printk(KERN_ERR "Could not allocate memory during boot, "
 		       "S3 disabled\n");
diff --git a/drivers/acpi/acpica/hwsleep.c b/drivers/acpi/acpica/hwsleep.c
index a2af2a4..bf719f1 100644
--- a/drivers/acpi/acpica/hwsleep.c
+++ b/drivers/acpi/acpica/hwsleep.c
@@ -46,6 +46,9 @@
 #include "accommon.h"
 #include "actables.h"
 
+#include <xen/acpi.h>
+#include <asm/xen/hypervisor.h>
+
 #define _COMPONENT          ACPI_HARDWARE
 ACPI_MODULE_NAME("hwsleep")
 
@@ -337,14 +340,19 @@ acpi_status asmlinkage acpi_enter_sleep_state(u8 sleep_state)
 
 	ACPI_FLUSH_CPU_CACHE();
 
-	status = acpi_hw_register_write(ACPI_REGISTER_PM1A_CONTROL,
-					PM1Acontrol);
-	if (ACPI_FAILURE(status)) {
-		return_ACPI_STATUS(status);
-	}
+	if (!xen_pv_domain()) {
+		status = acpi_hw_register_write(ACPI_REGISTER_PM1A_CONTROL,
+						PM1Acontrol);
+		if (ACPI_FAILURE(status)) {
+			return_ACPI_STATUS(status);
+		}
+
+		status = acpi_hw_register_write(ACPI_REGISTER_PM1B_CONTROL,
+						PM1Bcontrol);
+	} else
+		status = acpi_notify_hypervisor_state(sleep_state,
+						      PM1Acontrol, PM1Bcontrol);
 
-	status = acpi_hw_register_write(ACPI_REGISTER_PM1B_CONTROL,
-					PM1Bcontrol);
 	if (ACPI_FAILURE(status)) {
 		return_ACPI_STATUS(status);
 	}
diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index 5192666..c855dec 100644
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -59,7 +59,7 @@ static int acpi_sleep_prepare(u32 acpi_state)
 {
 #ifdef CONFIG_ACPI_SLEEP
 	/* do we have a wakeup address for S2 and S3? */
-	if (acpi_state == ACPI_STATE_S3) {
+	if (!xen_pv_domain() && acpi_state == ACPI_STATE_S3) {
 		if (!acpi_wakeup_address) {
 			return -EFAULT;
 		}
@@ -242,7 +242,16 @@ static int acpi_suspend_enter(suspend_state_t pm_state)
 		break;
 
 	case ACPI_STATE_S3:
-		do_suspend_lowlevel();
+		if (!xen_pv_domain())
+			do_suspend_lowlevel();
+		else {
+			/*
+			 * Xen will save and restore CPU context, so
+			 * we can skip that and just go straight to
+			 * the suspend.
+			 */
+			acpi_enter_sleep_state(acpi_state);
+		}
 		break;
 	}
 
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index 51cbaa5..0138113 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -76,3 +76,7 @@ config XEN_COMPAT_XENFS
 
 config XEN_XENBUS_FRONTEND
        tristate
+
+config XEN_S3
+       def_bool y
+       depends on XEN_DOM0 && ACPI
\ No newline at end of file
diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index bb88673..4b01fc8 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -7,4 +7,6 @@ obj-$(CONFIG_XEN_BALLOON)		+= balloon.o
 obj-$(CONFIG_XEN_DEV_EVTCHN)	+= evtchn.o
 obj-$(CONFIG_XEN_BLKDEV_BACKEND)	+= blkback/
 obj-$(CONFIG_XEN_NETDEV_BACKEND)	+= netback/
-obj-$(CONFIG_XENFS)			+= xenfs/
\ No newline at end of file
+obj-$(CONFIG_XENFS)			+= xenfs/
+
+obj-$(CONFIG_XEN_S3)			+= acpi.o
\ No newline at end of file
diff --git a/drivers/xen/acpi.c b/drivers/xen/acpi.c
new file mode 100644
index 0000000..e6d3d0e
--- /dev/null
+++ b/drivers/xen/acpi.c
@@ -0,0 +1,23 @@
+#include <xen/acpi.h>
+
+#include <xen/interface/platform.h>
+#include <asm/xen/hypercall.h>
+#include <asm/xen/hypervisor.h>
+
+int acpi_notify_hypervisor_state(u8 sleep_state,
+				 u32 pm1a_cnt, u32 pm1b_cnt)
+{
+	struct xen_platform_op op = {
+		.cmd = XENPF_enter_acpi_sleep,
+		.interface_version = XENPF_INTERFACE_VERSION,
+		.u = {
+			.enter_acpi_sleep = {
+				.pm1a_cnt_val = (u16)pm1a_cnt,
+				.pm1b_cnt_val = (u16)pm1b_cnt,
+				.sleep_state = sleep_state,
+			},
+		},
+	};
+
+	return HYPERVISOR_dom0_op(&op);
+}
diff --git a/include/xen/acpi.h b/include/xen/acpi.h
new file mode 100644
index 0000000..0d1e462
--- /dev/null
+++ b/include/xen/acpi.h
@@ -0,0 +1,9 @@
+#ifndef _XEN_ACPI_H
+#define _XEN_ACPI_H
+
+#include <linux/types.h>
+
+int acpi_notify_hypervisor_state(u8 sleep_state,
+				 u32 pm1a_cnt, u32 pm1b_cnd);
+
+#endif	/* _XEN_ACPI_H */