ARM: vfp: Use cpu pm notifiers to save vfp state

When the cpu is powered down in a low power mode, the vfp
registers may be reset.

This patch uses CPU_PM_ENTER and CPU_PM_EXIT notifiers to save
and restore the cpu's vfp registers.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-and-Acked-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Vishwanath BS <vishwanath.bs@ti.com>

1 files changed, 21 insertions, 8 deletions

diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
index 79bcb431693..fe4b60b1e6c 100644
--- a/arch/arm/vfp/vfpmodule.c
+++ b/arch/arm/vfp/vfpmodule.c
@@ -11,6 +11,7 @@
 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/cpu.h>
+#include <linux/cpu_pm.h>
 #include <linux/kernel.h>
 #include <linux/notifier.h>
 #include <linux/signal.h>
@@ -436,9 +437,7 @@ static void vfp_enable(void *unused)
         set_copro_access(access | CPACC_FULL(10) | CPACC_FULL(11));
 }
 
-#ifdef CONFIG_PM
-#include <linux/syscore_ops.h>
-
+#ifdef CONFIG_CPU_PM
 static int vfp_pm_suspend(void)
 {
         struct thread_info *ti = current_thread_info();
@@ -468,19 +467,33 @@ static void vfp_pm_resume(void)
         fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_EN);
 }
 
-static struct syscore_ops vfp_pm_syscore_ops = {
-        .suspend        = vfp_pm_suspend,
-        .resume         = vfp_pm_resume,
+static int vfp_cpu_pm_notifier(struct notifier_block *self, unsigned long cmd,
+        void *v)
+{
+        switch (cmd) {
+        case CPU_PM_ENTER:
+                vfp_pm_suspend();
+                break;
+        case CPU_PM_ENTER_FAILED:
+        case CPU_PM_EXIT:
+                vfp_pm_resume();
+                break;
+        }
+        return NOTIFY_OK;
+}
+
+static struct notifier_block vfp_cpu_pm_notifier_block = {
+        .notifier_call = vfp_cpu_pm_notifier,
 };
 
 static void vfp_pm_init(void)
 {
-        register_syscore_ops(&vfp_pm_syscore_ops);
+        cpu_pm_register_notifier(&vfp_cpu_pm_notifier_block);
 }
 
 #else
 static inline void vfp_pm_init(void) { }
-#endif /* CONFIG_PM */
+#endif /* CONFIG_CPU_PM */
 
 /*
  * Ensure that the VFP state stored in 'thread->vfpstate' is up to date