[PATCH] cpuidle: move field disable from per-driver to per-cpu

[ShuoX Liu <shuox.liu@intel.com>]

From: ShuoX Liu <shuox.liu@intel.com>

Andrew J.Schorr raises a question. When he changes the disable setting
on a single CPU, it affects all the other CPUs. Basically, currently,
the disable field is per-driver instead of per-cpu. All the C states of
the same driver are shared by all CPU in the same machine.

Below patch changes field disable to per-cpu, so we could set this
separately for each cpu.

Reported-by: Andrew J.Schorr <aschorr@telemetry-investments.com>
Reviewed-by: Yanmin Zhang <yanmin_zhang@intel.com>
Signed-off-by: ShuoX Liu <shuox.liu@intel.com>
---
 drivers/cpuidle/cpuidle.c        |    1 -
 drivers/cpuidle/governors/menu.c |    5 +++--
 drivers/cpuidle/sysfs.c          |   21 ++++++++++++---------
 include/linux/cpuidle.h          |    2 +-
 4 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index d90519c..04e4b76 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -265,7 +265,6 @@ static void poll_idle_init(struct cpuidle_driver *drv)
 	state->power_usage = -1;
 	state->flags = 0;
 	state->enter = poll_idle;
-	state->disable = 0;
 }
 #else
 static void poll_idle_init(struct cpuidle_driver *drv) {}
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index 0633575..8391d93 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -281,7 +281,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 	 * unless the timer is happening really really soon.
 	 */
 	if (data->expected_us > 5 &&
-		drv->states[CPUIDLE_DRIVER_STATE_START].disable == 0)
+		dev->states_usage[CPUIDLE_DRIVER_STATE_START].disable == 0)
 		data->last_state_idx = CPUIDLE_DRIVER_STATE_START;
 
 	/*
@@ -290,8 +290,9 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 	 */
 	for (i = CPUIDLE_DRIVER_STATE_START; i < drv->state_count; i++) {
 		struct cpuidle_state *s = &drv->states[i];
+		struct cpuidle_state_usage *su = &dev->states_usage[i];
 
-		if (s->disable)
+		if (su->disable)
 			continue;
 		if (s->target_residency > data->predicted_us)
 			continue;
diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c
index 88032b4..5f809e3 100644
--- a/drivers/cpuidle/sysfs.c
+++ b/drivers/cpuidle/sysfs.c
@@ -217,7 +217,8 @@ struct cpuidle_state_attr {
 	struct attribute attr;
 	ssize_t (*show)(struct cpuidle_state *, \
 					struct cpuidle_state_usage *, char *);
-	ssize_t (*store)(struct cpuidle_state *, const char *, size_t);
+	ssize_t (*store)(struct cpuidle_state *, \
+			struct cpuidle_state_usage *, const char *, size_t);
 };
 
 #define define_one_state_ro(_name, show) \
@@ -233,21 +234,22 @@ static ssize_t show_state_##_name(struct cpuidle_state *state, \
 	return sprintf(buf, "%u\n", state->_name);\
 }
 
-#define define_store_state_function(_name) \
+#define define_store_state_ull_function(_name) \
 static ssize_t store_state_##_name(struct cpuidle_state *state, \
+		struct cpuidle_state_usage *state_usage, \
 		const char *buf, size_t size) \
 { \
-	long value; \
+	unsigned long long value; \
 	int err; \
 	if (!capable(CAP_SYS_ADMIN)) \
 		return -EPERM; \
-	err = kstrtol(buf, 0, &value); \
+	err = kstrtoull(buf, 0, &value); \
 	if (err) \
 		return err; \
 	if (value) \
-		state->disable = 1; \
+		state_usage->_name = 1; \
 	else \
-		state->disable = 0; \
+		state_usage->_name = 0; \
 	return size; \
 }
 
@@ -273,8 +275,8 @@ define_show_state_ull_function(usage)
 define_show_state_ull_function(time)
 define_show_state_str_function(name)
 define_show_state_str_function(desc)
-define_show_state_function(disable)
-define_store_state_function(disable)
+define_show_state_ull_function(disable)
+define_store_state_ull_function(disable)
 
 define_one_state_ro(name, show_state_name);
 define_one_state_ro(desc, show_state_desc);
@@ -318,10 +320,11 @@ static ssize_t cpuidle_state_store(struct kobject *kobj,
 {
 	int ret = -EIO;
 	struct cpuidle_state *state = kobj_to_state(kobj);
+	struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
 	struct cpuidle_state_attr *cattr = attr_to_stateattr(attr);
 
 	if (cattr->store)
-		ret = cattr->store(state, buf, size);
+		ret = cattr->store(state, state_usage, buf, size);
 
 	return ret;
 }
diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index 6c26a3d..8570012 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -34,6 +34,7 @@ struct cpuidle_driver;
 struct cpuidle_state_usage {
 	void		*driver_data;
 
+	unsigned long long	disable;
 	unsigned long long	usage;
 	unsigned long long	time; /* in US */
 };
@@ -46,7 +47,6 @@ struct cpuidle_state {
 	unsigned int	exit_latency; /* in US */
 	int		power_usage; /* in mW */
 	unsigned int	target_residency; /* in US */
-	unsigned int    disable;
 
 	int (*enter)	(struct cpuidle_device *dev,
 			struct cpuidle_driver *drv,
-- 
1.7.1