[PATCH v2 35/44] cpuidle,omap3: Push RCU-idle into omap_sram_idle()

From: Peter Zijlstra
Date: Mon Sep 19 2022 - 06:21:48 EST


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) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Tony Lindgren <tony@xxxxxxxxxxx>
Tested-by: Tony Lindgren <tony@xxxxxxxxxxx>
---
arch/arm/mach-omap2/cpuidle34xx.c | 4 +---
arch/arm/mach-omap2/pm.h | 2 +-
arch/arm/mach-omap2/pm34xx.c | 12 ++++++++++--
3 files changed, 12 insertions(+), 6 deletions(-)

--- a/arch/arm/mach-omap2/cpuidle34xx.c
+++ b/arch/arm/mach-omap2/cpuidle34xx.c
@@ -133,9 +133,7 @@ static int omap3_enter_idle(struct cpuid
}

/* 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
--- a/arch/arm/mach-omap2/pm.h
+++ b/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)
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/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(unsigne
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 */