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-rw-r--r--arch/arm/mach-shmobile/hotplug.c32
1 files changed, 31 insertions, 1 deletions
diff --git a/arch/arm/mach-shmobile/hotplug.c b/arch/arm/mach-shmobile/hotplug.c
index 238a0d97d2d..828d22f3af5 100644
--- a/arch/arm/mach-shmobile/hotplug.c
+++ b/arch/arm/mach-shmobile/hotplug.c
@@ -12,14 +12,43 @@
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/smp.h>
+#include <linux/cpumask.h>
+#include <linux/delay.h>
+#include <mach/common.h>
+#include <asm/cacheflush.h>
+
+static cpumask_t dead_cpus;
int platform_cpu_kill(unsigned int cpu)
{
- return 1;
+ int k;
+
+ /* this function is running on another CPU than the offline target,
+ * here we need wait for shutdown code in platform_cpu_die() to
+ * finish before asking SoC-specific code to power off the CPU core.
+ */
+ for (k = 0; k < 1000; k++) {
+ if (cpumask_test_cpu(cpu, &dead_cpus))
+ return shmobile_platform_cpu_kill(cpu);
+
+ mdelay(1);
+ }
+
+ return 0;
}
void platform_cpu_die(unsigned int cpu)
{
+ /* hardware shutdown code running on the CPU that is being offlined */
+ flush_cache_all();
+ dsb();
+
+ /* notify platform_cpu_kill() that hardware shutdown is finished */
+ cpumask_set_cpu(cpu, &dead_cpus);
+
+ /* wait for SoC code in platform_cpu_kill() to shut off CPU core
+ * power. CPU bring up starts from the reset vector.
+ */
while (1) {
/*
* here's the WFI
@@ -33,6 +62,7 @@ void platform_cpu_die(unsigned int cpu)
int platform_cpu_disable(unsigned int cpu)
{
+ cpumask_clear_cpu(cpu, &dead_cpus);
/*
* we don't allow CPU 0 to be shutdown (it is still too special
* e.g. clock tick interrupts)