>From: Jeremy Fitzhardinge [mailto:jeremy@xxxxxxxx]
>Sent: Tuesday, March 24, 2009 1:15 PM
>
>Rafael J. Wysocki wrote:
>> Yes, that may be better.
>>
>
>How does this look now? I had a second look at the Xen-hooks,
>and found
>that they were mostly unnecessary (they were preventing useless code
>from running, but there's no harm in letting it run).
The reason why those useless code are prevented, is in case of
clobberring 0-1M area which if contains valid Xen content. in
acpi_save_state_mem, dom0's wakeup code is copied to area
allocated in acpi_reserve_bootmem. If every Xen's usage on 0-1M
is based on copy-on-use style, such as trampoline code for AP
boot, it's ok. But I'm not sure whether Xen puts some persistent
content there. IIRC, that boot time allocation usually returns sth
like 0x90000 since wakeup stub is first run in real mode. But if
for dom0 alloc_bootmem_low never gives <1M page, then this
prevention could be skipped as your thought.
>
>The result is below. Does this look reasonable?
>
>Thanks,
> J
>
>diff --git a/arch/x86/kernel/acpi/sleep.c
>b/arch/x86/kernel/acpi/sleep.c
>index 7c243a2..8ebda00 100644
>--- a/arch/x86/kernel/acpi/sleep.c
>+++ b/arch/x86/kernel/acpi/sleep.c
>@@ -12,6 +12,9 @@
> #include <asm/segment.h>
> #include <asm/desc.h>
>
>+#include <xen/acpi.h>
>+#include <asm/xen/hypervisor.h>
>+
> #include "realmode/wakeup.h"
> #include "sleep.h"
>
>@@ -25,6 +28,34 @@ static unsigned long acpi_realmode;
> static char temp_stack[4096];
> #endif
>
>+/*
>+ * Override final register write when entering sleep state so we can
>+ * direct it to a hypercall in the Xen case.
>+ */
>+acpi_status arch_acpi_enter_sleep_state(u8 sleep_state, u32
>+ PM1Acontrol, u32 PM1Bcontrol)
>+{
>+ acpi_status ret;
>+
>+ if (xen_pv_acpi()) {
>+ int err;
>+
>+ err = acpi_notify_hypervisor_state(sleep_state,
>+ PM1Acontrol,
>PM1Bcontrol);
>+
>+ ret = AE_OK;
>+ if (err) {
>+ ACPI_DEBUG_PRINT((ACPI_DB_INIT,
>+ "Hypervisor failure
>[%d]\n", err));
>+ ret = AE_ERROR;
>+ }
>+ } else
>+ ret = default_acpi_enter_sleep_state(sleep_state,
>+
>PM1Acontrol, PM1Bcontrol);
>+
>+ return ret;
>+}
>+
> /**
> * acpi_save_state_mem - save kernel state
> *
>diff --git a/drivers/acpi/acpica/hwsleep.c
>b/drivers/acpi/acpica/hwsleep.c
>index a2af2a4..6196a7e 100644
>--- a/drivers/acpi/acpica/hwsleep.c
>+++ b/drivers/acpi/acpica/hwsleep.c
>@@ -209,6 +209,83 @@ acpi_status
>acpi_enter_sleep_state_prep(u8 sleep_state)
>
> ACPI_EXPORT_SYMBOL(acpi_enter_sleep_state_prep)
>
>+/*
>+ * Default implementation of final register write to enter sleep
>+ * state, available for architecture versions to call if necessary.
>+ */
>+acpi_status default_acpi_enter_sleep_state(u8 sleep_state, u32
>+ PM1Acontrol, u32 PM1Bcontrol)
>+{
>+ acpi_status status;
>+ u32 in_value;
>+
>+ 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);
>+
>+ if (ACPI_FAILURE(status)) {
>+ return_ACPI_STATUS(status);
>+ }
>+
>+ if (sleep_state > ACPI_STATE_S3) {
>+ struct acpi_bit_register_info *sleep_enable_reg_info;
>+
>+ /*
>+ * We wanted to sleep > S3, but it didn't
>happen (by virtue of the
>+ * fact that we are still executing!)
>+ *
>+ * Wait ten seconds, then try again. This is to
>get S4/S5 to work on
>+ * all machines.
>+ *
>+ * We wait so long to allow chipsets that poll
>this reg very slowly to
>+ * still read the right value. Ideally, this
>block would go
>+ * away entirely.
>+ */
>+ acpi_os_stall(10000000);
>+
>+ sleep_enable_reg_info =
>+
>acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);
>+
>+ status =
>acpi_hw_register_write(ACPI_REGISTER_PM1_CONTROL,
>+ sleep_enable_reg_info->
>+ access_bit_mask);
>+ if (ACPI_FAILURE(status)) {
>+ return_ACPI_STATUS(status);
>+ }
>+ }
>+
>+ /* Wait until we enter sleep state */
>+
>+ do {
>+ status =
>acpi_get_register_unlocked(ACPI_BITREG_WAKE_STATUS,
>+ &in_value);
>+ if (ACPI_FAILURE(status)) {
>+ return_ACPI_STATUS(status);
>+ }
>+
>+ /* Spin until we wake */
>+
>+ } while (!in_value);
>+
>+ return_ACPI_STATUS(AE_OK);
>+}
>+
>+/*
>+ * Weak version of final write to enter sleep state, so that
>+ * architectures can override it.
>+ */
>+acpi_status __weak arch_acpi_enter_sleep_state(u8 sleep_state,
>+ u32 PM1Acontrol,
>u32 PM1Bcontrol)
>+{
>+ return default_acpi_enter_sleep_state(sleep_state,
>+ PM1Acontrol, PM1Bcontrol);
>+}
>+
>
>/**************************************************************
>*****************
> *
> * FUNCTION: acpi_enter_sleep_state
>@@ -227,7 +304,6 @@ acpi_status asmlinkage
>acpi_enter_sleep_state(u8 sleep_state)
> u32 PM1Bcontrol;
> struct acpi_bit_register_info *sleep_type_reg_info;
> struct acpi_bit_register_info *sleep_enable_reg_info;
>- u32 in_value;
> struct acpi_object_list arg_list;
> union acpi_object arg;
> acpi_status status;
>@@ -337,54 +413,7 @@ 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);
>- }
>-
>- status = acpi_hw_register_write(ACPI_REGISTER_PM1B_CONTROL,
>- PM1Bcontrol);
>- if (ACPI_FAILURE(status)) {
>- return_ACPI_STATUS(status);
>- }
>-
>- if (sleep_state > ACPI_STATE_S3) {
>- /*
>- * We wanted to sleep > S3, but it didn't
>happen (by virtue of the
>- * fact that we are still executing!)
>- *
>- * Wait ten seconds, then try again. This is to
>get S4/S5 to work on
>- * all machines.
>- *
>- * We wait so long to allow chipsets that poll
>this reg very slowly to
>- * still read the right value. Ideally, this
>block would go
>- * away entirely.
>- */
>- acpi_os_stall(10000000);
>-
>- status =
>acpi_hw_register_write(ACPI_REGISTER_PM1_CONTROL,
>- sleep_enable_reg_info->
>- access_bit_mask);
>- if (ACPI_FAILURE(status)) {
>- return_ACPI_STATUS(status);
>- }
>- }
>-
>- /* Wait until we enter sleep state */
>-
>- do {
>- status =
>acpi_get_register_unlocked(ACPI_BITREG_WAKE_STATUS,
>- &in_value);
>- if (ACPI_FAILURE(status)) {
>- return_ACPI_STATUS(status);
>- }
>-
>- /* Spin until we wake */
>-
>- } while (!in_value);
>-
>- return_ACPI_STATUS(AE_OK);
>+ return arch_acpi_enter_sleep_state(sleep_state,
>PM1Acontrol, PM1Bcontrol);
> }
>
> ACPI_EXPORT_SYMBOL(acpi_enter_sleep_state)
>diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
>index 5192666..bd1cc1a 100644
>--- a/drivers/acpi/sleep.c
>+++ b/drivers/acpi/sleep.c
>@@ -19,6 +19,8 @@
>
> #include <asm/io.h>
>
>+#include <xen/acpi.h>
>+
> #include <acpi/acpi_bus.h>
> #include <acpi/acpi_drivers.h>
> #include "sleep.h"
>@@ -209,6 +211,21 @@ static int
>acpi_suspend_begin(suspend_state_t pm_state)
> return error;
> }
>
>+static void do_suspend(void)
>+{
>+ if (!xen_pv_acpi()) {
>+ do_suspend_lowlevel();
>+ return;
>+ }
>+
>+ /*
>+ * 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_S3);
>+}
>+
> /**
> * acpi_suspend_enter - Actually enter a sleep state.
> * @pm_state: ignored
>@@ -242,7 +259,7 @@ static int
>acpi_suspend_enter(suspend_state_t pm_state)
> break;
>
> case ACPI_STATE_S3:
>- do_suspend_lowlevel();
>+ do_suspend();
> 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/acpi/acpixf.h b/include/acpi/acpixf.h
>index cc40102..f39f396 100644
>--- a/include/acpi/acpixf.h
>+++ b/include/acpi/acpixf.h
>@@ -372,6 +372,12 @@ acpi_status
>acpi_enter_sleep_state_prep(u8 sleep_state);
>
> acpi_status asmlinkage acpi_enter_sleep_state(u8 sleep_state);
>
>+acpi_status __weak arch_acpi_enter_sleep_state(u8 sleep_state,
>+ u32 PM1Acontrol,
>u32 PM1Bcontrol);
>+
>+acpi_status default_acpi_enter_sleep_state(u8 sleep_state,
>+ u32 PM1Acontrol, u32
>PM1Bcontrol);
>+
> acpi_status asmlinkage acpi_enter_sleep_state_s4bios(void);
>
> acpi_status acpi_leave_sleep_state_prep(u8 sleep_state);
>diff --git a/include/xen/acpi.h b/include/xen/acpi.h
>new file mode 100644
>index 0000000..fea4cfb
>--- /dev/null
>+++ b/include/xen/acpi.h
>@@ -0,0 +1,23 @@
>+#ifndef _XEN_ACPI_H
>+#define _XEN_ACPI_H
>+
>+#include <linux/types.h>
>+
>+#ifdef CONFIG_XEN_S3
>+#include <asm/xen/hypervisor.h>
>+
>+static inline bool xen_pv_acpi(void)
>+{
>+ return xen_pv_domain();
>+}
>+#else
>+static inline bool xen_pv_acpi(void)
>+{
>+ return false;
>+}
>+#endif
>+
>+int acpi_notify_hypervisor_state(u8 sleep_state,
>+ u32 pm1a_cnt, u32 pm1b_cnd);
>+
>+#endif /* _XEN_ACPI_H */
>
>
>
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