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authorLi Shaohua <shaohua.li@intel.com>2005-06-25 14:55:06 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-06-25 16:24:32 -0700
commit5a72e04df5470df0ec646029d31e5528167ab1a7 (patch)
tree11be00c3ed3d8bad775e6eec44078c9f942537b9 /kernel
parentfb69c3907ead36b9e9f41ea6f0d0e0ae10a38a47 (diff)
[PATCH] suspend/resume SMP support
Using CPU hotplug to support suspend/resume SMP. Both S3 and S4 use disable/enable_nonboot_cpus API. The S4 part is based on Pavel's original S4 SMP patch. Signed-off-by: Li Shaohua<shaohua.li@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/power/Kconfig6
-rw-r--r--kernel/power/Makefile6
-rw-r--r--kernel/power/disk.c35
-rw-r--r--kernel/power/main.c16
-rw-r--r--kernel/power/smp.c89
-rw-r--r--kernel/power/swsusp.c2
6 files changed, 72 insertions, 82 deletions
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index 696387ffe49..fdb37763650 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -28,7 +28,7 @@ config PM_DEBUG
config SOFTWARE_SUSPEND
bool "Software Suspend (EXPERIMENTAL)"
- depends on EXPERIMENTAL && PM && SWAP
+ depends on EXPERIMENTAL && PM && SWAP && (SUSPEND_SMP || !SMP)
---help---
Enable the possibility of suspending the machine.
It doesn't need APM.
@@ -72,3 +72,7 @@ config PM_STD_PARTITION
suspended image to. It will simply pick the first available swap
device.
+config SUSPEND_SMP
+ bool
+ depends on HOTPLUG_CPU && X86 && PM
+ default y
diff --git a/kernel/power/Makefile b/kernel/power/Makefile
index fbdc634135a..2f438d0eaa1 100644
--- a/kernel/power/Makefile
+++ b/kernel/power/Makefile
@@ -3,9 +3,9 @@ ifeq ($(CONFIG_PM_DEBUG),y)
EXTRA_CFLAGS += -DDEBUG
endif
-swsusp-smp-$(CONFIG_SMP) += smp.o
-
obj-y := main.o process.o console.o pm.o
-obj-$(CONFIG_SOFTWARE_SUSPEND) += swsusp.o $(swsusp-smp-y) disk.o
+obj-$(CONFIG_SOFTWARE_SUSPEND) += swsusp.o disk.o
+
+obj-$(CONFIG_SUSPEND_SMP) += smp.o
obj-$(CONFIG_MAGIC_SYSRQ) += poweroff.o
diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index 02b6764034d..fb8de63c291 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -117,8 +117,8 @@ static void finish(void)
{
device_resume();
platform_finish();
- enable_nonboot_cpus();
thaw_processes();
+ enable_nonboot_cpus();
pm_restore_console();
}
@@ -131,28 +131,35 @@ static int prepare_processes(void)
sys_sync();
+ disable_nonboot_cpus();
+
if (freeze_processes()) {
error = -EBUSY;
- return error;
+ goto thaw;
}
if (pm_disk_mode == PM_DISK_PLATFORM) {
if (pm_ops && pm_ops->prepare) {
if ((error = pm_ops->prepare(PM_SUSPEND_DISK)))
- return error;
+ goto thaw;
}
}
/* Free memory before shutting down devices. */
free_some_memory();
-
return 0;
+thaw:
+ thaw_processes();
+ enable_nonboot_cpus();
+ pm_restore_console();
+ return error;
}
static void unprepare_processes(void)
{
- enable_nonboot_cpus();
+ platform_finish();
thaw_processes();
+ enable_nonboot_cpus();
pm_restore_console();
}
@@ -160,15 +167,9 @@ static int prepare_devices(void)
{
int error;
- disable_nonboot_cpus();
- if ((error = device_suspend(PMSG_FREEZE))) {
+ if ((error = device_suspend(PMSG_FREEZE)))
printk("Some devices failed to suspend\n");
- platform_finish();
- enable_nonboot_cpus();
- return error;
- }
-
- return 0;
+ return error;
}
/**
@@ -185,9 +186,9 @@ int pm_suspend_disk(void)
int error;
error = prepare_processes();
- if (!error) {
- error = prepare_devices();
- }
+ if (error)
+ return error;
+ error = prepare_devices();
if (error) {
unprepare_processes();
@@ -250,7 +251,7 @@ static int software_resume(void)
if ((error = prepare_processes())) {
swsusp_close();
- goto Cleanup;
+ goto Done;
}
pr_debug("PM: Reading swsusp image.\n");
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 4cdebc972ff..c94cb9e9509 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -55,6 +55,13 @@ static int suspend_prepare(suspend_state_t state)
pm_prepare_console();
+ disable_nonboot_cpus();
+
+ if (num_online_cpus() != 1) {
+ error = -EPERM;
+ goto Enable_cpu;
+ }
+
if (freeze_processes()) {
error = -EAGAIN;
goto Thaw;
@@ -75,6 +82,8 @@ static int suspend_prepare(suspend_state_t state)
pm_ops->finish(state);
Thaw:
thaw_processes();
+ Enable_cpu:
+ enable_nonboot_cpus();
pm_restore_console();
return error;
}
@@ -113,6 +122,7 @@ static void suspend_finish(suspend_state_t state)
if (pm_ops && pm_ops->finish)
pm_ops->finish(state);
thaw_processes();
+ enable_nonboot_cpus();
pm_restore_console();
}
@@ -150,12 +160,6 @@ static int enter_state(suspend_state_t state)
goto Unlock;
}
- /* Suspend is hard to get right on SMP. */
- if (num_online_cpus() != 1) {
- error = -EPERM;
- goto Unlock;
- }
-
pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
if ((error = suspend_prepare(state)))
goto Unlock;
diff --git a/kernel/power/smp.c b/kernel/power/smp.c
index 457c2302ed4..bbe23079c62 100644
--- a/kernel/power/smp.c
+++ b/kernel/power/smp.c
@@ -13,73 +13,52 @@
#include <linux/interrupt.h>
#include <linux/suspend.h>
#include <linux/module.h>
+#include <linux/cpu.h>
#include <asm/atomic.h>
#include <asm/tlbflush.h>
-static atomic_t cpu_counter, freeze;
-
-
-static void smp_pause(void * data)
-{
- struct saved_context ctxt;
- __save_processor_state(&ctxt);
- printk("Sleeping in:\n");
- dump_stack();
- atomic_inc(&cpu_counter);
- while (atomic_read(&freeze)) {
- /* FIXME: restore takes place at random piece inside this.
- This should probably be written in assembly, and
- preserve general-purpose registers, too
-
- What about stack? We may need to move to new stack here.
-
- This should better be ran with interrupts disabled.
- */
- cpu_relax();
- barrier();
- }
- atomic_dec(&cpu_counter);
- __restore_processor_state(&ctxt);
-}
-
-static cpumask_t oldmask;
+/* This is protected by pm_sem semaphore */
+static cpumask_t frozen_cpus;
void disable_nonboot_cpus(void)
{
- oldmask = current->cpus_allowed;
- set_cpus_allowed(current, cpumask_of_cpu(0));
- printk("Freezing CPUs (at %d)", raw_smp_processor_id());
- current->state = TASK_INTERRUPTIBLE;
- schedule_timeout(HZ);
- printk("...");
- BUG_ON(raw_smp_processor_id() != 0);
-
- /* FIXME: for this to work, all the CPUs must be running
- * "idle" thread (or we deadlock). Is that guaranteed? */
+ int cpu, error;
- atomic_set(&cpu_counter, 0);
- atomic_set(&freeze, 1);
- smp_call_function(smp_pause, NULL, 0, 0);
- while (atomic_read(&cpu_counter) < (num_online_cpus() - 1)) {
- cpu_relax();
- barrier();
+ error = 0;
+ cpus_clear(frozen_cpus);
+ printk("Freezing cpus ...\n");
+ for_each_online_cpu(cpu) {
+ if (cpu == 0)
+ continue;
+ error = cpu_down(cpu);
+ if (!error) {
+ cpu_set(cpu, frozen_cpus);
+ printk("CPU%d is down\n", cpu);
+ continue;
+ }
+ printk("Error taking cpu %d down: %d\n", cpu, error);
}
- printk("ok\n");
+ BUG_ON(smp_processor_id() != 0);
+ if (error)
+ panic("cpus not sleeping");
}
void enable_nonboot_cpus(void)
{
- printk("Restarting CPUs");
- atomic_set(&freeze, 0);
- while (atomic_read(&cpu_counter)) {
- cpu_relax();
- barrier();
- }
- printk("...");
- set_cpus_allowed(current, oldmask);
- schedule();
- printk("ok\n");
+ int cpu, error;
+ printk("Thawing cpus ...\n");
+ for_each_cpu_mask(cpu, frozen_cpus) {
+ error = smp_prepare_cpu(cpu);
+ if (!error)
+ error = cpu_up(cpu);
+ if (!error) {
+ printk("CPU%d is up\n", cpu);
+ continue;
+ }
+ printk("Error taking cpu %d up: %d\n", cpu, error);
+ panic("Not enough cpus");
+ }
+ cpus_clear(frozen_cpus);
}
-
diff --git a/kernel/power/swsusp.c b/kernel/power/swsusp.c
index 53f9f8720ee..339b5c3735b 100644
--- a/kernel/power/swsusp.c
+++ b/kernel/power/swsusp.c
@@ -1193,8 +1193,10 @@ static const char * sanity_check(void)
return "version";
if (strcmp(swsusp_info.uts.machine,system_utsname.machine))
return "machine";
+#if 0
if(swsusp_info.cpus != num_online_cpus())
return "number of cpus";
+#endif
return NULL;
}