[PATCH 1/2]: pSeries: Enable cpuidle for pSeries.

Arun R Bharadwaj
2009-08-19T12:58:44Z

* Arun R Bharadwaj <arun@linux.vnet.ibm.com> [2009-08-19 18:27:16]:

This patch enables the cpuidle option in Kconfig for pSeries.
It also adds the routine cpu_idle_wait.

Signed-off-by: Arun R Bharadwaj <arun@linux.vnet.ibm.com>
---
arch/powerpc/Kconfig | 18 ++++++++++++++++++
arch/powerpc/include/asm/system.h | 2 ++
arch/powerpc/platforms/pseries/setup.c | 20 ++++++++++++++++++++
drivers/cpuidle/cpuidle.c | 1 +
4 files changed, 41 insertions(+)

Index: linux.trees.git/arch/powerpc/Kconfig
===================================================================
--- linux.trees.git.orig/arch/powerpc/Kconfig
+++ linux.trees.git/arch/powerpc/Kconfig
@@ -88,6 +88,9 @@ config ARCH_HAS_ILOG2_U64
bool
default y if 64BIT

+config ARCH_HAS_CPU_IDLE_WAIT
+ def_bool y
+
config GENERIC_HWEIGHT
bool
default y
@@ -243,6 +246,21 @@ source "kernel/Kconfig.freezer"
source "arch/powerpc/sysdev/Kconfig"
source "arch/powerpc/platforms/Kconfig"

+menu "Power management options"
+
+source "drivers/cpuidle/Kconfig"
+
+config TPMD
+ tristate "TPMD power management support"
+ depends on PPC_PSERIES && CPU_IDLE
+ default y
+ help
+ Thermal and Power Management Devices (TPMD). This hooks onto cpuidle
+ infrastructure to help in idle cpu power management. Currently this
+ is enabled only for pSeries.
+
+endmenu
+
menu "Kernel options"

config HIGHMEM
Index: linux.trees.git/drivers/cpuidle/cpuidle.c
===================================================================
--- linux.trees.git.orig/drivers/cpuidle/cpuidle.c
+++ linux.trees.git/drivers/cpuidle/cpuidle.c
@@ -17,6 +17,7 @@
#include <linux/cpuidle.h>
#include <linux/ktime.h>
#include <linux/hrtimer.h>
+#include <linux/pm.h>

#include "cpuidle.h"

Index: linux.trees.git/arch/powerpc/platforms/pseries/setup.c
===================================================================
--- linux.trees.git.orig/arch/powerpc/platforms/pseries/setup.c
+++ linux.trees.git/arch/powerpc/platforms/pseries/setup.c
@@ -278,6 +278,26 @@ static struct notifier_block pci_dn_reco
.notifier_call = pci_dn_reconfig_notifier,
};

+static void do_nothing(void *unused)
+{
+}
+
+/*
+ * cpu_idle_wait - Used to ensure that all the CPUs discard old value of
+ * pm_idle and update to new pm_idle value. Required while changing pm_idle
+ * handler on SMP systems.
+ *
+ * Caller must have changed pm_idle to the new value before the call. Old
+ * pm_idle value will not be used by any CPU after the return of this function.
+ */
+void cpu_idle_wait(void)
+{
+ smp_mb();
+ /* kick all the CPUs so that they exit out of pm_idle */
+ smp_call_function(do_nothing, NULL, 1);
+}
+EXPORT_SYMBOL_GPL(cpu_idle_wait);
+
static void __init pSeries_setup_arch(void)
{
/* Discover PIC type and setup ppc_md accordingly */
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
@@ -546,5 +546,7 @@ extern void account_system_vtime(struct

extern struct dentry *powerpc_debugfs_root;

+void cpu_idle_wait(void);
+
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_SYSTEM_H */