From: Paul Mundt <lethal@linux-sh.org>
Date: Mon, 26 Apr 2010 09:59:47 +0000 (+0900)
Subject: sh: cache secondary CPUs idle loop.
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=8db2bc4559639680a94d4492ae4b7ce71298a74f;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

sh: cache secondary CPUs idle loop.

This provides a cache of the secondary CPUs idle loop for the cases where
hotplug simply enters a low power state instead of resetting or powering
off the core.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
---

diff --git a/arch/sh/include/asm/processor.h b/arch/sh/include/asm/processor.h
index 26b3f026eec9..0a58cb25a658 100644
--- a/arch/sh/include/asm/processor.h
+++ b/arch/sh/include/asm/processor.h
@@ -85,6 +85,10 @@ struct sh_cpuinfo {
 	struct tlb_info itlb;
 	struct tlb_info dtlb;
 
+#ifdef CONFIG_SMP
+	struct task_struct *idle;
+#endif
+
 	unsigned long flags;
 } __attribute__ ((aligned(L1_CACHE_BYTES)));
 
diff --git a/arch/sh/kernel/smp.c b/arch/sh/kernel/smp.c
index 3711a76a18e0..21e7f8a9f3e4 100644
--- a/arch/sh/kernel/smp.c
+++ b/arch/sh/kernel/smp.c
@@ -125,10 +125,15 @@ int __cpuinit __cpu_up(unsigned int cpu)
 	struct task_struct *tsk;
 	unsigned long timeout;
 
-	tsk = fork_idle(cpu);
-	if (IS_ERR(tsk)) {
-		printk(KERN_ERR "Failed forking idle task for cpu %d\n", cpu);
-		return PTR_ERR(tsk);
+	tsk = cpu_data[cpu].idle;
+	if (!tsk) {
+		tsk = fork_idle(cpu);
+		if (IS_ERR(tsk)) {
+			pr_err("Failed forking idle task for cpu %d\n", cpu);
+			return PTR_ERR(tsk);
+		}
+
+		cpu_data[cpu].idle = tsk;
 	}
 
 	per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;