From: Gary King <gking@nvidia.com>
Date: Wed, 24 Mar 2010 21:46:53 +0000 (-0700)
Subject: ARM: enable CONFIG_CPU_IDLE support
X-Git-Tag: firefly_0821_release~9833^2~381
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=1512cef47070413a175399c73c5f3636e4902162;p=firefly-linux-kernel-4.4.55.git

ARM: enable CONFIG_CPU_IDLE support

add ARCH_HAS_CPU_IDLE_WAIT and ARCH_HAS_DEFAULT_IDLE configuration,
and expose default_idle and cpu_idle_wait

cpu_idle_wait implementation based on the implementation in the x86 tree

Signed-off-by: Gary King <gking@nvidia.com>
---

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 0c33e5aa44cd..6d122de88693 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -132,6 +132,14 @@ config RWSEM_GENERIC_SPINLOCK
 config RWSEM_XCHGADD_ALGORITHM
 	bool
 
+config ARCH_HAS_CPU_IDLE_WAIT
+	bool
+	default y
+
+config ARCH_HAS_DEFAULT_IDLE
+	bool
+	default y
+
 config ARCH_HAS_ILOG2_U32
 	bool
 
diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
index 8ba1ccf82a02..549c9786e0f9 100644
--- a/arch/arm/include/asm/system.h
+++ b/arch/arm/include/asm/system.h
@@ -97,6 +97,8 @@ extern void __show_regs(struct pt_regs *);
 
 extern int cpu_architecture(void);
 extern void cpu_init(void);
+extern void cpu_idle_wait(void);
+extern void default_idle(void);
 
 void arm_machine_restart(char mode, const char *cmd);
 extern void (*arm_pm_restart)(char str, const char *cmd);
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 401e38be1f78..69141f0b8388 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -140,12 +140,13 @@ EXPORT_SYMBOL_GPL(arm_pm_restart);
  * This is our default idle handler.  We need to disable
  * interrupts here to ensure we don't miss a wakeup call.
  */
-static void default_idle(void)
+void default_idle(void)
 {
 	if (!need_resched())
 		arch_idle();
 	local_irq_enable();
 }
+EXPORT_SYMBOL(default_idle);
 
 void (*pm_idle)(void) = default_idle;
 EXPORT_SYMBOL(pm_idle);
@@ -195,6 +196,19 @@ void cpu_idle(void)
 	}
 }
 
+#if defined(CONFIG_ARCH_HAS_CPU_IDLE_WAIT)
+static void do_nothing(void *unused)
+{
+}
+
+void cpu_idle_wait(void)
+{
+	smp_mb();
+	smp_call_function(do_nothing, NULL, 1);
+}
+#endif
+
+
 static char reboot_mode = 'h';
 
 int __init reboot_setup(char *str)