cpuidle, OMAP3: Push RCU-idle into omap_sram_idle()

OMAP3 uses full SoC suspend modes as idle states, as such it needs the
whole power-domain and clock-domain code from the idle path.

All that code is not suitable to run with RCU disabled, as such push
RCU-idle deeper still.

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Tested-by: Tony Lindgren <[email protected]>
Tested-by: Ulf Hansson <[email protected]>
Reviewed-by: Tony Lindgren <[email protected]>
Acked-by: Rafael J. Wysocki <[email protected]>
Acked-by: Frederic Weisbecker <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: Peter Zijlstra

arch/arm/mach-omap2/cpuidle34xx.c

@@ -133,9 +133,7 @@ static int omap3_enter_idle(struct cpuidle_device *dev,
 	}
 
 	/* Execute ARM wfi */
-	ct_cpuidle_enter();
-	omap_sram_idle();
-	ct_cpuidle_exit();
+	omap_sram_idle(true);
 
 	/*
 	 * Call idle CPU PM enter notifier chain to restore

arch/arm/mach-omap2/pm.h

@@ -29,7 +29,7 @@ static inline int omap4_idle_init(void)
 
 extern void *omap3_secure_ram_storage;
 extern void omap3_pm_off_mode_enable(int);
-extern void omap_sram_idle(void);
+extern void omap_sram_idle(bool rcuidle);
 extern int omap_pm_clkdms_setup(struct clockdomain *clkdm, void *unused);
 
 #if defined(CONFIG_PM_OPP)

arch/arm/mach-omap2/pm34xx.c

@@ -26,6 +26,7 @@
 #include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/of.h>
+#include <linux/cpuidle.h>
 
 #include <trace/events/power.h>
 
@@ -174,7 +175,7 @@ static int omap34xx_do_sram_idle(unsigned long save_state)
 	return 0;
 }
 
-void omap_sram_idle(void)
+void omap_sram_idle(bool rcuidle)
 {
 	/* Variable to tell what needs to be saved and restored
 	 * in omap_sram_idle*/
@@ -254,11 +255,18 @@ void omap_sram_idle(void)
 	 */
 	if (save_state)
 		omap34xx_save_context(omap3_arm_context);
+
+	if (rcuidle)
+		ct_cpuidle_enter();
+
 	if (save_state == 1 || save_state == 3)
 		cpu_suspend(save_state, omap34xx_do_sram_idle);
 	else
 		omap34xx_do_sram_idle(save_state);
 
+	if (rcuidle)
+		ct_cpuidle_exit();
+
 	/* Restore normal SDRC POWER settings */
 	if (cpu_is_omap3430() && omap_rev() >= OMAP3430_REV_ES3_0 &&
 	    (omap_type() == OMAP2_DEVICE_TYPE_EMU ||
@@ -316,7 +324,7 @@ static int omap3_pm_suspend(void)
 
 	omap3_intc_suspend();
 
-	omap_sram_idle();
+	omap_sram_idle(false);
 
 restore:
 	/* Restore next_pwrsts */