xen / ACPI: notify xen when reduced hardware sleep is available

Use the acpi_os_prepare_extended_sleep() callback to notify xen
to make use of the reduced hardware sleep functionality

The xen hypervisor change underlying this is commit 62d1a69
("ACPI: support v5 (reduced HW) sleep interface") on the master
branch of git://xenbits.xen.org/xen.git.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Ben Guthro <benjamin.guthro@citrix.com>
Acked-by: Konrad Wilk <konrad.wilk@oracle.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/xen/acpi.c

@@ -35,28 +35,43 @@
 #include <asm/xen/hypercall.h>
 #include <asm/xen/hypervisor.h>
 
-int xen_acpi_notify_hypervisor_state(u8 sleep_state,
-				     u32 pm1a_cnt, u32 pm1b_cnt)
+static int xen_acpi_notify_hypervisor_state(u8 sleep_state,
+					    u32 val_a, u32 val_b,
+					    bool extended)
 {
+	unsigned int bits = extended ? 8 : 16;
+
 	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,
-			},
+		.u.enter_acpi_sleep = {
+			.val_a = (u16)val_a,
+			.val_b = (u16)val_b,
+			.sleep_state = sleep_state,
+			.flags = extended ? XENPF_ACPI_SLEEP_EXTENDED : 0,
 		},
 	};
 
-	if ((pm1a_cnt & 0xffff0000) || (pm1b_cnt & 0xffff0000)) {
-		WARN(1, "Using more than 16bits of PM1A/B 0x%x/0x%x!"
-		     "Email xen-devel@lists.xensource.com  Thank you.\n", \
-		     pm1a_cnt, pm1b_cnt);
+	if (WARN((val_a & (~0 << bits)) || (val_b & (~0 << bits)),
+		 "Using more than %u bits of sleep control values %#x/%#x!"
+		 "Email xen-devel@lists.xen.org - Thank you.\n", \
+		 bits, val_a, val_b))
 		return -1;
-	}
 
 	HYPERVISOR_dom0_op(&op);
 	return 1;
 }
+
+int xen_acpi_notify_hypervisor_sleep(u8 sleep_state,
+				     u32 pm1a_cnt, u32 pm1b_cnt)
+{
+	return xen_acpi_notify_hypervisor_state(sleep_state, pm1a_cnt,
+						pm1b_cnt, false);
+}
+
+int xen_acpi_notify_hypervisor_extended_sleep(u8 sleep_state,
+				     u32 val_a, u32 val_b)
+{
+	return xen_acpi_notify_hypervisor_state(sleep_state, val_a,
+						val_b, true);
+}

include/xen/acpi.h

@@ -75,8 +75,10 @@ static inline int xen_acpi_get_pxm(acpi_handle h)
 	return -ENXIO;
 }
 
-int xen_acpi_notify_hypervisor_state(u8 sleep_state,
+int xen_acpi_notify_hypervisor_sleep(u8 sleep_state,
 				     u32 pm1a_cnt, u32 pm1b_cnd);
+int xen_acpi_notify_hypervisor_extended_sleep(u8 sleep_state,
+				     u32 val_a, u32 val_b);
 
 static inline int xen_acpi_suspend_lowlevel(void)
 {
@@ -93,7 +95,9 @@ static inline void xen_acpi_sleep_register(void)
 {
 	if (xen_initial_domain()) {
 		acpi_os_set_prepare_sleep(
-			&xen_acpi_notify_hypervisor_state);
+			&xen_acpi_notify_hypervisor_sleep);
+		acpi_os_set_prepare_extended_sleep(
+			&xen_acpi_notify_hypervisor_extended_sleep);
 
 		acpi_suspend_lowlevel = xen_acpi_suspend_lowlevel;
 	}

include/xen/interface/platform.h

@@ -152,10 +152,11 @@ DEFINE_GUEST_HANDLE_STRUCT(xenpf_firmware_info_t);
 #define XENPF_enter_acpi_sleep    51
 struct xenpf_enter_acpi_sleep {
 	/* IN variables */
-	uint16_t pm1a_cnt_val;      /* PM1a control value. */
-	uint16_t pm1b_cnt_val;      /* PM1b control value. */
+	uint16_t val_a;             /* PM1a control / sleep type A. */
+	uint16_t val_b;             /* PM1b control / sleep type B. */
 	uint32_t sleep_state;       /* Which state to enter (Sn). */
-	uint32_t flags;             /* Must be zero. */
+#define XENPF_ACPI_SLEEP_EXTENDED 0x00000001
+	uint32_t flags;             /* XENPF_ACPI_SLEEP_*. */
 };
 DEFINE_GUEST_HANDLE_STRUCT(xenpf_enter_acpi_sleep_t);