[RFC][PATCH 1/2] cpuidle: Drop disabled field from struct cpuidle_state

Rafael J. Wysocki
2019-11-18T23:10:05Z

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

After recent cpuidle updates the disabled field in struct
cpuidle_state is only used by two drivers (intel_idle and shmobile
cpuidle) for marking unusable idle states, but that may as well be
achieved with the help of a state flag, so define an "unusable" idle
state flag, CPUIDLE_FLAG_UNUSABLE, make the drivers in question use
it instead of the disable field and make the core set
CPUIDLE_STATE_DISABLED_BY_DRIVER for the idle states with that flag
set.

After the above changes, the disabled field in struct cpuidle_state
is not used any more, so drop it.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
arch/sh/kernel/cpu/shmobile/cpuidle.c | 8 ++++----
drivers/cpuidle/cpuidle.c | 2 +-
drivers/cpuidle/poll_state.c | 1 -
drivers/idle/intel_idle.c | 6 +++---
include/linux/cpuidle.h | 2 +-
5 files changed, 9 insertions(+), 10 deletions(-)

Index: linux-pm/drivers/idle/intel_idle.c
===================================================================
--- linux-pm.orig/drivers/idle/intel_idle.c
+++ linux-pm/drivers/idle/intel_idle.c
@@ -1291,8 +1291,8 @@ static void sklh_idle_state_table_update
return;
}

- skl_cstates[5].disabled = 1; /* C8-SKL */
- skl_cstates[6].disabled = 1; /* C9-SKL */
+ skl_cstates[5].flags |= CPUIDLE_FLAG_UNUSABLE; /* C8-SKL */
+ skl_cstates[6].flags |= CPUIDLE_FLAG_UNUSABLE; /* C9-SKL */
}
/*
* intel_idle_state_table_update()
@@ -1355,7 +1355,7 @@ static void __init intel_idle_cpuidle_dr
continue;

/* if state marked as disabled, skip it */
- if (cpuidle_state_table[cstate].disabled != 0) {
+ if (cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_UNUSABLE) {
pr_debug("state %s is disabled\n",
cpuidle_state_table[cstate].name);
continue;
Index: linux-pm/include/linux/cpuidle.h
===================================================================
--- linux-pm.orig/include/linux/cpuidle.h
+++ linux-pm/include/linux/cpuidle.h
@@ -54,7 +54,6 @@ struct cpuidle_state {
unsigned int exit_latency; /* in US */
int power_usage; /* in mW */
unsigned int target_residency; /* in US */
- bool disabled; /* disabled on all CPUs */

int (*enter) (struct cpuidle_device *dev,
struct cpuidle_driver *drv,
@@ -77,6 +76,7 @@ struct cpuidle_state {
#define CPUIDLE_FLAG_POLLING BIT(0) /* polling state */
#define CPUIDLE_FLAG_COUPLED BIT(1) /* state applies to multiple cpus */
#define CPUIDLE_FLAG_TIMER_STOP BIT(2) /* timer is stopped on this state */
+#define CPUIDLE_FLAG_UNUSABLE BIT(3) /* avoid using this state */

struct cpuidle_device_kobj;
struct cpuidle_state_kobj;
Index: linux-pm/arch/sh/kernel/cpu/shmobile/cpuidle.c
===================================================================
--- linux-pm.orig/arch/sh/kernel/cpu/shmobile/cpuidle.c
+++ linux-pm/arch/sh/kernel/cpu/shmobile/cpuidle.c
@@ -67,7 +67,7 @@ static struct cpuidle_driver cpuidle_dri
.enter = cpuidle_sleep_enter,
.name = "C2",
.desc = "SuperH Sleep Mode [SF]",
- .disabled = true,
+ .flags = CPUIDLE_FLAG_UNUSABLE,
},
{
.exit_latency = 2300,
@@ -76,7 +76,7 @@ static struct cpuidle_driver cpuidle_dri
.enter = cpuidle_sleep_enter,
.name = "C3",
.desc = "SuperH Mobile Standby Mode [SF]",
- .disabled = true,
+ .flags = CPUIDLE_FLAG_UNUSABLE,
},
},
.safe_state_index = 0,
@@ -86,10 +86,10 @@ static struct cpuidle_driver cpuidle_dri
int __init sh_mobile_setup_cpuidle(void)
{
if (sh_mobile_sleep_supported & SUSP_SH_SF)
- cpuidle_driver.states[1].disabled = false;
+ cpuidle_driver.states[1].flags = CPUIDLE_FLAG_NONE;

if (sh_mobile_sleep_supported & SUSP_SH_STANDBY)
- cpuidle_driver.states[2].disabled = false;
+ cpuidle_driver.states[2].flags = CPUIDLE_FLAG_NONE;

return cpuidle_register(&cpuidle_driver, NULL);
}
Index: linux-pm/drivers/cpuidle/cpuidle.c
===================================================================
--- linux-pm.orig/drivers/cpuidle/cpuidle.c
+++ linux-pm/drivers/cpuidle/cpuidle.c
@@ -570,7 +570,7 @@ static int __cpuidle_register_device(str
return -EINVAL;

for (i = 0; i < drv->state_count; i++)
- if (drv->states[i].disabled)
+ if (drv->states[i].flags & CPUIDLE_FLAG_UNUSABLE)
dev->states_usage[i].disable |= CPUIDLE_STATE_DISABLED_BY_DRIVER;

per_cpu(cpuidle_devices, dev->cpu) = dev;
Index: linux-pm/drivers/cpuidle/poll_state.c
===================================================================
--- linux-pm.orig/drivers/cpuidle/poll_state.c
+++ linux-pm/drivers/cpuidle/poll_state.c
@@ -53,7 +53,6 @@ void cpuidle_poll_state_init(struct cpui
state->target_residency_ns = 0;
state->power_usage = -1;
state->enter = poll_idle;
- state->disabled = false;
state->flags = CPUIDLE_FLAG_POLLING;
}
EXPORT_SYMBOL_GPL(cpuidle_poll_state_init);