On 02/21/2010 04:37 PM, Rafael J. Wysocki wrote:
> On Sunday 21 February 2010, Brian King wrote:
>> On 02/21/2010 04:27 PM, Rafael J. Wysocki wrote:
>>> On Sunday 21 February 2010, Brian King wrote:
>>>> On 02/21/2010 04:08 PM, Rafael J. Wysocki wrote:
>>>>> I'm not a big fan of __attribute__ ((weak)), though. While we already use that
>>>>> in the suspend code, I'm not particularly comfortable with it.
>>>>>
>>>>> Have you considered any alternative approaches?
>>>>
>>>> I suppose another option would be to implement this similar to how
>>>> arch_free_page and arch_alloc_page do. Something like this:
>>>>
>>>> #ifndef CONFIG_HAVE_ARCH_SUSPEND_CPUS
>>>> static inline int arch_suspend_disable_nonboot_cpus(void)
>>>> {
>>>> return disable_nonboot_cpus();
>>>> }
>>>>
>>>> static inline void arch_suspend_enable_nonboot_cpus(void)
>>>> {
>>>> return enable_nonboot_cpus()'
>>>> }
>>>> #else
>>>> extern int arch_suspend_disable_nonboot_cpus(void);
>>>> extern void arch_suspend_enable_nonboot_cpus(void);
>>>> #endif
>>>>
>>>> I figured I would just be consistent with arch_suspend_disable_irqs /
>>>> arch_suspend_enable_irqs.
>>>
>>> I just think that doing arch_suspend_[enable|disable]_irqs() this way was
>>> a mistake.
>>
>> Do you prefer the example above? I can send an updated patch. If not,
>> any other suggestions you might have as to the way you would like this
>> done would be greatly appreciated.
>
> disable_nonboot_cpus() is also called by kernel_power_off(). Is that fine
> with your architecture?
Yes. We only need a different behavior for the suspend/resume path.
Here is an alternative implementation of the patch. My test machine is
currently unavailable, so it is not yet been tested. How does this one look?
Thanks,
Brian
--
Brian King
Linux on Power Virtualization
IBM Linux Technology Center
Rather than calling disable_nonboot_cpus and enable_nonboot_cpus
directly, wrapper the calls in arch_suspend_disable_nonboot_cpus
and arch_suspend_enable_nonboot_cpus that can be overridden by
architectures that require different handling of suspending processors
at suspend time than these functions provide. This is needed to enable
suspend/resume on IBM Power servers.
Signed-off-by: Brian King <brking@xxxxxxxxxxxxxxxxxx>
---
include/linux/suspend.h | 27 +++++++++++++++++++++++++++
kernel/power/suspend.c | 4 ++--
2 files changed, 29 insertions(+), 2 deletions(-)
diff -puN include/linux/suspend.h~suspend_new_arch_smp include/linux/suspend.h
--- linux-2.6/include/linux/suspend.h~suspend_new_arch_smp 2010-02-21 16:32:04.000000000 -0600
+++ linux-2.6-bjking1/include/linux/suspend.h 2010-02-21 16:45:36.000000000 -0600
@@ -141,6 +141,33 @@ extern void arch_suspend_disable_irqs(vo
*/
extern void arch_suspend_enable_irqs(void);
+#ifdef CONFIG_HAVE_ARCH_SUSPEND_CPUS
+extern int arch_suspend_disable_nonboot_cpus(void);
+extern void arch_suspend_enable_nonboot_cpus(void);
+#else
+/**
+ * arch_suspend_disable_nonboot_cpus - disable non boot for suspend
+ *
+ * Disables non boot CPUs (in the default case). Architectures can
+ * override this if more needs to be done. Not called for suspend to disk.
+ */
+static inline int arch_suspend_disable_nonboot_cpus(void)
+{
+ return disable_nonboot_cpus();
+}
+
+/**
+ * arch_suspend_enable_nonboot_cpus - enable non boot after suspend
+ *
+ * Enables non boot CPUs (in the default case). Architectures can
+ * override this if more needs to be done. Not called for suspend to disk.
+ */
+static inline void arch_suspend_enable_nonboot_cpus(void)
+{
+ enable_nonboot_cpus();
+}
+#endif
+
extern int pm_suspend(suspend_state_t state);
#else /* !CONFIG_SUSPEND */
#define suspend_valid_only_mem NULL
diff -puN kernel/power/suspend.c~suspend_new_arch_smp kernel/power/suspend.c
--- linux-2.6/kernel/power/suspend.c~suspend_new_arch_smp 2010-02-21 16:34:00.000000000 -0600
+++ linux-2.6-bjking1/kernel/power/suspend.c 2010-02-21 16:34:35.000000000 -0600
@@ -147,7 +147,7 @@ static int suspend_enter(suspend_state_t
if (suspend_test(TEST_PLATFORM))
goto Platform_wake;
- error = disable_nonboot_cpus();
+ error = arch_suspend_disable_nonboot_cpus();
if (error || suspend_test(TEST_CPUS))
goto Enable_cpus;
@@ -165,7 +165,7 @@ static int suspend_enter(suspend_state_t
BUG_ON(irqs_disabled());
Enable_cpus:
- enable_nonboot_cpus();
+ arch_suspend_enable_nonboot_cpus();
Platform_wake:
if (suspend_ops->wake)
_
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