Re: [v10 PATCH 8/9]: pSeries: implement pSeries processor idlemodule
From: Arun R Bharadwaj
Date: Fri Dec 04 2009 - 03:15:55 EST
* Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> [2009-12-04 13:47:38]:
> On Wed, 2009-12-02 at 15:32 +0530, Arun R Bharadwaj wrote:
> > * Arun R Bharadwaj <arun@xxxxxxxxxxxxxxxxxx> [2009-12-02 15:24:27]:
> >
> > This patch creates arch/powerpc/platforms/pseries/processor_idle.c,
> > which implements the cpuidle infrastructure for pseries.
> > It implements a pseries_cpuidle_loop() which would be the main idle loop
> > called from cpu_idle(). It makes decision of entering either
> > dedicated_snooze_loop or dedicated_cede_loop for dedicated lpar and
> > shared_cede_loop for shared lpar processor based on the
> > decision taken by the cpuidle governor.
>
> So unless I'm mistaken, you removed our powerpc "generic" idle loop that
> calls into ppc_md.power_save(), and replaced it by some pseries specific
> idle loops... Now what about all the other powerpc platforms ? native
> 970 (aka G5) ? 6xx ? Cell ? Or are you still calling ppc_md.power_save
> somewhere that I missed ?
>
> Cheers,
> Ben.
Hi Ben,
I forgot to attach the patch which enables cpuidle for the rest of the
POWER platforms. Attaching it below.
So for these platforms, ppc_md.power_save will be called from from the
cpuidle_idle_call idle loop itself. Also, this cpuidle_idle_call is
not a pseries specific idle loop. It is a common loop for Intel and
PPC which use cpuidle infrastructure.
arun
This patch enables cpuidle for the rest of the POWER platforms like
44x, Cell, Pasemi etc.
Signed-off-by: Arun R Bharadwaj <arun@xxxxxxxxxxxxxxxxxx>
---
arch/powerpc/include/asm/system.h | 2 ++
arch/powerpc/kernel/idle.c | 28 ++++++++++++++++++++++++++++
arch/powerpc/kernel/setup_32.c | 8 ++++++--
arch/powerpc/platforms/44x/idle.c | 2 ++
arch/powerpc/platforms/cell/pervasive.c | 2 ++
arch/powerpc/platforms/pasemi/idle.c | 2 ++
arch/powerpc/platforms/ps3/setup.c | 2 ++
7 files changed, 44 insertions(+), 2 deletions(-)
Index: linux.trees.git/arch/powerpc/include/asm/system.h
===================================================================
--- linux.trees.git.orig/arch/powerpc/include/asm/system.h
+++ linux.trees.git/arch/powerpc/include/asm/system.h
@@ -551,8 +551,10 @@ void cpu_idle_wait(void);
#ifdef CONFIG_CPU_IDLE
extern void update_smt_snooze_delay(int snooze);
+extern void setup_cpuidle_ppc(void);
#else
static inline void update_smt_snooze_delay(int snooze) {}
+static inline void setup_cpuidle_ppc(void) {}
#endif
#endif /* __KERNEL__ */
Index: linux.trees.git/arch/powerpc/kernel/idle.c
===================================================================
--- linux.trees.git.orig/arch/powerpc/kernel/idle.c
+++ linux.trees.git/arch/powerpc/kernel/idle.c
@@ -129,6 +129,34 @@ void default_idle(void)
HMT_very_low();
}
+#ifdef CONFIG_CPU_IDLE
+DEFINE_PER_CPU(struct cpuidle_device, ppc_idle_devices);
+struct cpuidle_driver cpuidle_ppc_driver = {
+ .name = "cpuidle_ppc",
+};
+
+static void ppc_idle_loop(struct cpuidle_device *dev, struct cpuidle_state *st)
+{
+ ppc_md.power_save();
+}
+
+void setup_cpuidle_ppc(void)
+{
+ struct cpuidle_device *dev;
+ int cpu;
+
+ cpuidle_register_driver(&cpuidle_ppc_driver);
+
+ for_each_online_cpu(cpu) {
+ dev = &per_cpu(ppc_idle_devices, cpu);
+ dev->cpu = cpu;
+ dev->states[0].enter = ppc_idle_loop;
+ dev->state_count = 1;
+ cpuidle_register_device(dev);
+ }
+}
+#endif
+
int powersave_nap;
#ifdef CONFIG_SYSCTL
Index: linux.trees.git/arch/powerpc/kernel/setup_32.c
===================================================================
--- linux.trees.git.orig/arch/powerpc/kernel/setup_32.c
+++ linux.trees.git/arch/powerpc/kernel/setup_32.c
@@ -133,14 +133,18 @@ notrace void __init machine_init(unsigne
#ifdef CONFIG_6xx
if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
- cpu_has_feature(CPU_FTR_CAN_NAP))
+ cpu_has_feature(CPU_FTR_CAN_NAP)) {
ppc_md.power_save = ppc6xx_idle;
+ setup_cpuidle_ppc();
+ }
#endif
#ifdef CONFIG_E500
if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
- cpu_has_feature(CPU_FTR_CAN_NAP))
+ cpu_has_feature(CPU_FTR_CAN_NAP)) {
ppc_md.power_save = e500_idle;
+ setup_cpuidle_ppc();
+ }
#endif
if (ppc_md.progress)
ppc_md.progress("id mach(): done", 0x200);
Index: linux.trees.git/arch/powerpc/platforms/44x/idle.c
===================================================================
--- linux.trees.git.orig/arch/powerpc/platforms/44x/idle.c
+++ linux.trees.git/arch/powerpc/platforms/44x/idle.c
@@ -24,6 +24,7 @@
#include <linux/of.h>
#include <linux/kernel.h>
#include <asm/machdep.h>
+#include <asm/system.h>
static int mode_spin;
@@ -46,6 +47,7 @@ int __init ppc44x_idle_init(void)
/* If we are not setting spin mode
then we set to wait mode */
ppc_md.power_save = &ppc44x_idle;
+ setup_cpuidle_ppc();
}
return 0;
Index: linux.trees.git/arch/powerpc/platforms/cell/pervasive.c
===================================================================
--- linux.trees.git.orig/arch/powerpc/platforms/cell/pervasive.c
+++ linux.trees.git/arch/powerpc/platforms/cell/pervasive.c
@@ -35,6 +35,7 @@
#include <asm/pgtable.h>
#include <asm/reg.h>
#include <asm/cell-regs.h>
+#include <asm/system.h>
#include "pervasive.h"
@@ -128,5 +129,6 @@ void __init cbe_pervasive_init(void)
}
ppc_md.power_save = cbe_power_save;
+ setup_cpuidle_ppc();
ppc_md.system_reset_exception = cbe_system_reset_exception;
}
Index: linux.trees.git/arch/powerpc/platforms/pasemi/idle.c
===================================================================
--- linux.trees.git.orig/arch/powerpc/platforms/pasemi/idle.c
+++ linux.trees.git/arch/powerpc/platforms/pasemi/idle.c
@@ -27,6 +27,7 @@
#include <asm/machdep.h>
#include <asm/reg.h>
#include <asm/smp.h>
+#include <asm/system.h>
#include "pasemi.h"
@@ -81,6 +82,7 @@ static int __init pasemi_idle_init(void)
ppc_md.system_reset_exception = pasemi_system_reset_exception;
ppc_md.power_save = modes[current_mode].entry;
+ setup_cpuidle_ppc();
printk(KERN_INFO "Using PA6T idle loop (%s)\n", modes[current_mode].name);
return 0;
Index: linux.trees.git/arch/powerpc/platforms/ps3/setup.c
===================================================================
--- linux.trees.git.orig/arch/powerpc/platforms/ps3/setup.c
+++ linux.trees.git/arch/powerpc/platforms/ps3/setup.c
@@ -33,6 +33,7 @@
#include <asm/prom.h>
#include <asm/lv1call.h>
#include <asm/ps3gpu.h>
+#include <asm/system.h>
#include "platform.h"
@@ -214,6 +215,7 @@ static void __init ps3_setup_arch(void)
prealloc_ps3flash_bounce_buffer();
ppc_md.power_save = ps3_power_save;
+ setup_cpuidle_ppc();
ps3_os_area_init();
DBG(" <- %s:%d\n", __func__, __LINE__);
--
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