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author | Nicolas Pitre <nicolas.pitre@linaro.org> | 2014-01-29 17:45:10 (GMT) |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2014-02-11 08:58:24 (GMT) |
commit | d8c6ad3184ca6516a5cf457af1afaa293d8f09c0 (patch) | |
tree | dd7c96a0808480aac612746a7747725794c11e24 | |
parent | ad68cc7a777948b77f15a3dc3510918ff87ed0c0 (diff) | |
download | linux-d8c6ad3184ca6516a5cf457af1afaa293d8f09c0.tar.xz |
sched/idle, PPC: Remove redundant cpuidle_idle_call()
The core idle loop now takes care of it. However a few things need
checking:
- Invocation of cpuidle_idle_call() in pseries_lpar_idle() happened
through arch_cpu_idle() and was therefore always preceded by a call
to ppc64_runlatch_off(). To preserve this property now that
cpuidle_idle_call() is invoked directly from core code, a call to
ppc64_runlatch_off() has been added to idle_loop_prolog() in
platforms/pseries/processor_idle.c.
- Similarly, cpuidle_idle_call() was followed by ppc64_runlatch_off()
so a call to the later has been added to idle_loop_epilog().
- And since arch_cpu_idle() always made sure to re-enable IRQs if they
were not enabled, this is now
done in idle_loop_epilog() as well.
The above was made in order to keep the execution flow close to the
original. I don't know if that was strictly necessary. Someone well
aquainted with the platform details might find some room for possible
optimizations.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-sh@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linaro-kernel@lists.linaro.org
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-47o4m03citrfg9y1vxic5asb@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r-- | arch/powerpc/platforms/pseries/setup.c | 34 | ||||
-rw-r--r-- | drivers/cpuidle/cpuidle-pseries.c | 5 |
2 files changed, 19 insertions, 20 deletions
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c index 8e639d7..c737d55 100644 --- a/arch/powerpc/platforms/pseries/setup.c +++ b/arch/powerpc/platforms/pseries/setup.c @@ -39,7 +39,6 @@ #include <linux/irq.h> #include <linux/seq_file.h> #include <linux/root_dev.h> -#include <linux/cpuidle.h> #include <linux/of.h> #include <linux/kexec.h> @@ -356,29 +355,24 @@ early_initcall(alloc_dispatch_log_kmem_cache); static void pseries_lpar_idle(void) { - /* This would call on the cpuidle framework, and the back-end pseries - * driver to go to idle states + /* + * Default handler to go into low thread priority and possibly + * low power mode by cedeing processor to hypervisor */ - if (cpuidle_idle_call()) { - /* On error, execute default handler - * to go into low thread priority and possibly - * low power mode by cedeing processor to hypervisor - */ - /* Indicate to hypervisor that we are idle. */ - get_lppaca()->idle = 1; + /* Indicate to hypervisor that we are idle. */ + get_lppaca()->idle = 1; - /* - * Yield the processor to the hypervisor. We return if - * an external interrupt occurs (which are driven prior - * to returning here) or if a prod occurs from another - * processor. When returning here, external interrupts - * are enabled. - */ - cede_processor(); + /* + * Yield the processor to the hypervisor. We return if + * an external interrupt occurs (which are driven prior + * to returning here) or if a prod occurs from another + * processor. When returning here, external interrupts + * are enabled. + */ + cede_processor(); - get_lppaca()->idle = 0; - } + get_lppaca()->idle = 0; } /* diff --git a/drivers/cpuidle/cpuidle-pseries.c b/drivers/cpuidle/cpuidle-pseries.c index 7ab564a..d486489 100644 --- a/drivers/cpuidle/cpuidle-pseries.c +++ b/drivers/cpuidle/cpuidle-pseries.c @@ -29,6 +29,7 @@ static struct cpuidle_state *cpuidle_state_table; static inline void idle_loop_prolog(unsigned long *in_purr) { + ppc64_runlatch_off(); *in_purr = mfspr(SPRN_PURR); /* * Indicate to the HV that we are idle. Now would be @@ -45,6 +46,10 @@ static inline void idle_loop_epilog(unsigned long in_purr) wait_cycles += mfspr(SPRN_PURR) - in_purr; get_lppaca()->wait_state_cycles = cpu_to_be64(wait_cycles); get_lppaca()->idle = 0; + + if (irqs_disabled()) + local_irq_enable(); + ppc64_runlatch_on(); } static int snooze_loop(struct cpuidle_device *dev, |