1 files changed, 41 insertions, 1 deletions

diff --git a/arch/arm/mach-imx/hotplug.c b/arch/arm/mach-imx/hotplug.c
index 89493abd497c..20ed2d56c1af 100644
--- a/arch/arm/mach-imx/hotplug.c
+++ b/arch/arm/mach-imx/hotplug.c
@@ -12,6 +12,7 @@
 
 #include <linux/errno.h>
 #include <asm/cacheflush.h>
+#include <asm/cp15.h>
 #include <mach/common.h>
 
 int platform_cpu_kill(unsigned int cpu)
@@ -19,6 +20,44 @@ int platform_cpu_kill(unsigned int cpu)
 	return 1;
 }
 
+static inline void cpu_enter_lowpower(void)
+{
+	unsigned int v;
+
+	flush_cache_all();
+	asm volatile(
+		"mcr	p15, 0, %1, c7, c5, 0\n"
+	"	mcr	p15, 0, %1, c7, c10, 4\n"
+	/*
+	 * Turn off coherency
+	 */
+	"	mrc	p15, 0, %0, c1, c0, 1\n"
+	"	bic	%0, %0, %3\n"
+	"	mcr	p15, 0, %0, c1, c0, 1\n"
+	"	mrc	p15, 0, %0, c1, c0, 0\n"
+	"	bic	%0, %0, %2\n"
+	"	mcr	p15, 0, %0, c1, c0, 0\n"
+	  : "=&r" (v)
+	  : "r" (0), "Ir" (CR_C), "Ir" (0x40)
+	  : "cc");
+}
+
+static inline void cpu_leave_lowpower(void)
+{
+	unsigned int v;
+
+	asm volatile(
+		"mrc	p15, 0, %0, c1, c0, 0\n"
+	"	orr	%0, %0, %1\n"
+	"	mcr	p15, 0, %0, c1, c0, 0\n"
+	"	mrc	p15, 0, %0, c1, c0, 1\n"
+	"	orr	%0, %0, %2\n"
+	"	mcr	p15, 0, %0, c1, c0, 1\n"
+	  : "=&r" (v)
+	  : "Ir" (CR_C), "Ir" (0x40)
+	  : "cc");
+}
+
 /*
  * platform-specific code to shutdown a CPU
  *
@@ -26,9 +65,10 @@ int platform_cpu_kill(unsigned int cpu)
  */
 void platform_cpu_die(unsigned int cpu)
 {
-	flush_cache_all();
+	cpu_enter_lowpower();
 	imx_enable_cpu(cpu, false);
 	cpu_do_idle();
+	cpu_leave_lowpower();
 
 	/* We should never return from idle */
 	panic("cpu %d unexpectedly exit from shutdown\n", cpu);