ARM: CPU hotplug: move cpu_killed completion to core code
Russell King [Tue, 30 Nov 2010 11:07:35 +0000 (11:07 +0000)]
We always need to wait for the dying CPU to reach a safe state before
taking it down, irrespective of the requirements of the platform.
Move the completion code into the ARM SMP hotplug code rather than
having each platform re-implement this.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/kernel/smp.c
arch/arm/mach-omap2/omap-hotplug.c
arch/arm/mach-realview/hotplug.c
arch/arm/mach-s5pv310/hotplug.c
arch/arm/mach-tegra/hotplug.c
arch/arm/mach-ux500/hotplug.c

index a30c409..8c81ff9 100644 (file)
@@ -24,6 +24,7 @@
 #include <linux/irq.h>
 #include <linux/percpu.h>
 #include <linux/clockchips.h>
+#include <linux/completion.h>
 
 #include <asm/atomic.h>
 #include <asm/cacheflush.h>
@@ -238,12 +239,20 @@ int __cpu_disable(void)
        return 0;
 }
 
+static DECLARE_COMPLETION(cpu_died);
+
 /*
  * called on the thread which is asking for a CPU to be shutdown -
  * waits until shutdown has completed, or it is timed out.
  */
 void __cpu_die(unsigned int cpu)
 {
+       if (!wait_for_completion_timeout(&cpu_died, msecs_to_jiffies(5000))) {
+               pr_err("CPU%u: cpu didn't die\n", cpu);
+               return;
+       }
+       printk(KERN_NOTICE "CPU%u: shutdown\n", cpu);
+
        if (!platform_cpu_kill(cpu))
                printk("CPU%u: unable to kill\n", cpu);
 }
@@ -263,9 +272,12 @@ void __ref cpu_die(void)
        local_irq_disable();
        idle_task_exit();
 
+       /* Tell __cpu_die() that this CPU is now safe to dispose of */
+       complete(&cpu_died);
+
        /*
         * actual CPU shutdown procedure is at least platform (if not
-        * CPU) specific
+        * CPU) specific.
         */
        platform_cpu_die(cpu);
 
index 6cee456..ace979d 100644 (file)
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/smp.h>
-#include <linux/completion.h>
 
 #include <asm/cacheflush.h>
 #include <mach/omap4-common.h>
 
-static DECLARE_COMPLETION(cpu_killed);
-
 int platform_cpu_kill(unsigned int cpu)
 {
-       return wait_for_completion_timeout(&cpu_killed, 5000);
+       return 1;
 }
 
 /*
@@ -42,8 +39,7 @@ void platform_cpu_die(unsigned int cpu)
                           this_cpu, cpu);
                BUG();
        }
-       pr_notice("CPU%u: shutdown\n", cpu);
-       complete(&cpu_killed);
+
        flush_cache_all();
        dsb();
 
index f95521a..7d58c16 100644 (file)
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/smp.h>
-#include <linux/completion.h>
 
 #include <asm/cacheflush.h>
 
 extern volatile int pen_release;
 
-static DECLARE_COMPLETION(cpu_killed);
-
 static inline void cpu_enter_lowpower(void)
 {
        unsigned int v;
@@ -95,7 +92,7 @@ static inline void platform_do_lowpower(unsigned int cpu)
 
 int platform_cpu_kill(unsigned int cpu)
 {
-       return wait_for_completion_timeout(&cpu_killed, 5000);
+       return 1;
 }
 
 /*
@@ -115,9 +112,6 @@ void platform_cpu_die(unsigned int cpu)
        }
 #endif
 
-       printk(KERN_NOTICE "CPU%u: shutdown\n", cpu);
-       complete(&cpu_killed);
-
        /*
         * we're ready for shutdown now, so do it
         */
index 03652c3..d7be70a 100644 (file)
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/smp.h>
-#include <linux/completion.h>
 
 #include <asm/cacheflush.h>
 
 extern volatile int pen_release;
 
-static DECLARE_COMPLETION(cpu_killed);
-
 static inline void cpu_enter_lowpower(void)
 {
        unsigned int v;
@@ -98,7 +95,7 @@ static inline void platform_do_lowpower(unsigned int cpu)
 
 int platform_cpu_kill(unsigned int cpu)
 {
-       return wait_for_completion_timeout(&cpu_killed, 5000);
+       return 1;
 }
 
 /*
@@ -118,9 +115,6 @@ void platform_cpu_die(unsigned int cpu)
        }
 #endif
 
-       printk(KERN_NOTICE "CPU%u: shutdown\n", cpu);
-       complete(&cpu_killed);
-
        /*
         * we're ready for shutdown now, so do it
         */
index 8e7f115..ecaa41c 100644 (file)
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/smp.h>
-#include <linux/completion.h>
 
 #include <asm/cacheflush.h>
 
-static DECLARE_COMPLETION(cpu_killed);
-
 static inline void cpu_enter_lowpower(void)
 {
        unsigned int v;
@@ -94,7 +91,7 @@ static inline void platform_do_lowpower(unsigned int cpu)
 
 int platform_cpu_kill(unsigned int cpu)
 {
-       return wait_for_completion_timeout(&cpu_killed, 5000);
+       return 1;
 }
 
 /*
@@ -114,9 +111,6 @@ void platform_cpu_die(unsigned int cpu)
        }
 #endif
 
-       printk(KERN_NOTICE "CPU%u: shutdown\n", cpu);
-       complete(&cpu_killed);
-
        /*
         * we're ready for shutdown now, so do it
         */
index b782a03..7a4890b 100644 (file)
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/smp.h>
-#include <linux/completion.h>
 
 #include <asm/cacheflush.h>
 
 extern volatile int pen_release;
 
-static DECLARE_COMPLETION(cpu_killed);
-
 static inline void platform_do_lowpower(unsigned int cpu)
 {
        flush_cache_all();
@@ -38,7 +35,7 @@ static inline void platform_do_lowpower(unsigned int cpu)
 
 int platform_cpu_kill(unsigned int cpu)
 {
-       return wait_for_completion_timeout(&cpu_killed, 5000);
+       return 1;
 }
 
 /*
@@ -58,9 +55,6 @@ void platform_cpu_die(unsigned int cpu)
        }
 #endif
 
-       printk(KERN_NOTICE "CPU%u: shutdown\n", cpu);
-       complete(&cpu_killed);
-
        /* directly enter low power state, skipping secure registers */
        platform_do_lowpower(cpu);
 }