[1/5] thermal: Initialize thermal subsystem earlier
diff mbox series

Message ID 97b6f861e6e6a2ac7b50efb7211f3c8e7fe872b0.1568240476.git.amit.kucheria@linaro.org
State Changes Requested, archived
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Series
  • Initialise thermal framework earlier during boot
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Commit Message

Amit Kucheria Sept. 11, 2019, 10:32 p.m. UTC
From: Lina Iyer <ilina@codeaurora.org>

Now that the thermal framework is built-in, in order to facilitate
thermal mitigation as early as possible in the boot cycle, move the
thermal framework initialization to core_initcall.

However, netlink initialization happens only as part of subsys_initcall.
At this time in the boot process, the userspace is not available yet. So
initialize the netlink events later in fs_initcall.

Signed-off-by: Lina Iyer <ilina@codeaurora.org>
[Rebased, refactored and moved to core_initcall]
Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
---
 drivers/thermal/thermal_core.c | 41 ++++++++++++++++++++--------------
 1 file changed, 24 insertions(+), 17 deletions(-)

Comments

Daniel Lezcano Sept. 16, 2019, 8 p.m. UTC | #1
On 12/09/2019 00:32, Amit Kucheria wrote:
> From: Lina Iyer <ilina@codeaurora.org>
> 
> Now that the thermal framework is built-in, in order to facilitate
> thermal mitigation as early as possible in the boot cycle, move the
> thermal framework initialization to core_initcall.
> 
> However, netlink initialization happens only as part of subsys_initcall.
> At this time in the boot process, the userspace is not available yet. So
> initialize the netlink events later in fs_initcall.

Why not kill directly the netlink part, no one is using it in the kernel?


> Signed-off-by: Lina Iyer <ilina@codeaurora.org>
> [Rebased, refactored and moved to core_initcall]
> Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
> ---
>  drivers/thermal/thermal_core.c | 41 ++++++++++++++++++++--------------
>  1 file changed, 24 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> index 6bab66e84eb5..b13e8a9298cc 100644
> --- a/drivers/thermal/thermal_core.c
> +++ b/drivers/thermal/thermal_core.c
> @@ -1468,6 +1468,8 @@ static struct genl_family thermal_event_genl_family __ro_after_init = {
>  	.n_mcgrps = ARRAY_SIZE(thermal_event_mcgrps),
>  };
>  
> +static bool allow_netlink_events;
> +
>  int thermal_generate_netlink_event(struct thermal_zone_device *tz,
>  				   enum events event)
>  {
> @@ -1482,6 +1484,9 @@ int thermal_generate_netlink_event(struct thermal_zone_device *tz,
>  	if (!tz)
>  		return -EINVAL;
>  
> +	if (!allow_netlink_events)
> +		return -ENODEV;
> +
>  	/* allocate memory */
>  	size = nla_total_size(sizeof(struct thermal_genl_event)) +
>  	       nla_total_size(0);
> @@ -1533,16 +1538,18 @@ EXPORT_SYMBOL_GPL(thermal_generate_netlink_event);
>  
>  static int __init genetlink_init(void)
>  {
> -	return genl_register_family(&thermal_event_genl_family);
> -}
> +	int ret;
>  
> -static void genetlink_exit(void)
> -{
> -	genl_unregister_family(&thermal_event_genl_family);
> +	ret = genl_register_family(&thermal_event_genl_family);
> +	if (!ret)
> +		allow_netlink_events = true;
> +	return ret;
>  }
> +
>  #else /* !CONFIG_NET */
>  static inline int genetlink_init(void) { return 0; }
> -static inline void genetlink_exit(void) {}
> +static inline int thermal_generate_netlink_event(struct thermal_zone_device *tz,
> +						 enum events event) { return -ENODEV; }
>  #endif /* !CONFIG_NET */
>  
>  static int thermal_pm_notify(struct notifier_block *nb,
> @@ -1591,19 +1598,15 @@ static int __init thermal_init(void)
>  	mutex_init(&poweroff_lock);
>  	result = thermal_register_governors();
>  	if (result)
> -		goto error;
> +		goto init_exit;
>  
>  	result = class_register(&thermal_class);
>  	if (result)
>  		goto unregister_governors;
>  
> -	result = genetlink_init();
> -	if (result)
> -		goto unregister_class;
> -
>  	result = of_parse_thermal_zones();
>  	if (result)
> -		goto exit_netlink;
> +		goto exit_zone_parse;
>  
>  	result = register_pm_notifier(&thermal_pm_nb);
>  	if (result)
> @@ -1612,13 +1615,11 @@ static int __init thermal_init(void)
>  
>  	return 0;
>  
> -exit_netlink:
> -	genetlink_exit();
> -unregister_class:
> +exit_zone_parse:
>  	class_unregister(&thermal_class);
>  unregister_governors:
>  	thermal_unregister_governors();
> -error:
> +init_exit:
>  	ida_destroy(&thermal_tz_ida);
>  	ida_destroy(&thermal_cdev_ida);
>  	mutex_destroy(&thermal_list_lock);
> @@ -1626,4 +1627,10 @@ static int __init thermal_init(void)
>  	mutex_destroy(&poweroff_lock);
>  	return result;
>  }
> -fs_initcall(thermal_init);
> +
> +static int __init thermal_netlink_init(void)
> +{
> +	return genetlink_init();
> +}
> +core_initcall(thermal_init);
> +fs_initcall(thermal_netlink_init);
>
Amit Kucheria Sept. 17, 2019, 9:18 a.m. UTC | #2
On Tue, Sep 17, 2019 at 1:30 AM Daniel Lezcano
<daniel.lezcano@linaro.org> wrote:
>
> On 12/09/2019 00:32, Amit Kucheria wrote:
> > From: Lina Iyer <ilina@codeaurora.org>
> >
> > Now that the thermal framework is built-in, in order to facilitate
> > thermal mitigation as early as possible in the boot cycle, move the
> > thermal framework initialization to core_initcall.
> >
> > However, netlink initialization happens only as part of subsys_initcall.
> > At this time in the boot process, the userspace is not available yet. So
> > initialize the netlink events later in fs_initcall.
>
> Why not kill directly the netlink part, no one is using it in the kernel?

That's a good point. I wasn't sure if anybody was using it, but I can
remove it completely since no driver seems to be using the
thermal_generate_netlink_event() api.

Regards,
Amit

$ git grep thermal_generate_netlink_event
Documentation/thermal/sysfs-api.rst:just need to call
thermal_generate_netlink_event() with two arguments viz
drivers/thermal/thermal_core.c:int
thermal_generate_netlink_event(struct thermal_zone_device *tz,
drivers/thermal/thermal_core.c:EXPORT_SYMBOL_GPL(thermal_generate_netlink_event);
include/linux/thermal.h:extern int
thermal_generate_netlink_event(struct thermal_zone_device *tz,
include/linux/thermal.h:static inline int
thermal_generate_netlink_event(struct thermal_zone_device *tz,
Zhang Rui Sept. 19, 2019, 2:13 p.m. UTC | #3
On Tue, 2019-09-17 at 14:48 +0530, Amit Kucheria wrote:
> On Tue, Sep 17, 2019 at 1:30 AM Daniel Lezcano
> <daniel.lezcano@linaro.org> wrote:
> > 
> > On 12/09/2019 00:32, Amit Kucheria wrote:
> > > From: Lina Iyer <ilina@codeaurora.org>
> > > 
> > > Now that the thermal framework is built-in, in order to
> > > facilitate
> > > thermal mitigation as early as possible in the boot cycle, move
> > > the
> > > thermal framework initialization to core_initcall.
> > > 
> > > However, netlink initialization happens only as part of
> > > subsys_initcall.
> > > At this time in the boot process, the userspace is not available
> > > yet. So
> > > initialize the netlink events later in fs_initcall.
> > 
> > Why not kill directly the netlink part, no one is using it in the
> > kernel?
> 
> That's a good point. I wasn't sure if anybody was using it, but I can
> remove it completely since no driver seems to be using the
> thermal_generate_netlink_event() api.

Interesting, I recalled that thermal_generate_netlink_event() is indeed
used by some thermal driver, but it's true that no one is using it now.

let's remove it and see if we get any complains.

thanks,
rui
> 
> Regards,
> Amit
> 
> $ git grep thermal_generate_netlink_event
> Documentation/thermal/sysfs-api.rst:just need to call
> thermal_generate_netlink_event() with two arguments viz
> drivers/thermal/thermal_core.c:int
> thermal_generate_netlink_event(struct thermal_zone_device *tz,
> drivers/thermal/thermal_core.c:EXPORT_SYMBOL_GPL(thermal_generate_net
> link_event);
> include/linux/thermal.h:extern int
> thermal_generate_netlink_event(struct thermal_zone_device *tz,
> include/linux/thermal.h:static inline int
> thermal_generate_netlink_event(struct thermal_zone_device *tz,

Patch
diff mbox series

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 6bab66e84eb5..b13e8a9298cc 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -1468,6 +1468,8 @@  static struct genl_family thermal_event_genl_family __ro_after_init = {
 	.n_mcgrps = ARRAY_SIZE(thermal_event_mcgrps),
 };
 
+static bool allow_netlink_events;
+
 int thermal_generate_netlink_event(struct thermal_zone_device *tz,
 				   enum events event)
 {
@@ -1482,6 +1484,9 @@  int thermal_generate_netlink_event(struct thermal_zone_device *tz,
 	if (!tz)
 		return -EINVAL;
 
+	if (!allow_netlink_events)
+		return -ENODEV;
+
 	/* allocate memory */
 	size = nla_total_size(sizeof(struct thermal_genl_event)) +
 	       nla_total_size(0);
@@ -1533,16 +1538,18 @@  EXPORT_SYMBOL_GPL(thermal_generate_netlink_event);
 
 static int __init genetlink_init(void)
 {
-	return genl_register_family(&thermal_event_genl_family);
-}
+	int ret;
 
-static void genetlink_exit(void)
-{
-	genl_unregister_family(&thermal_event_genl_family);
+	ret = genl_register_family(&thermal_event_genl_family);
+	if (!ret)
+		allow_netlink_events = true;
+	return ret;
 }
+
 #else /* !CONFIG_NET */
 static inline int genetlink_init(void) { return 0; }
-static inline void genetlink_exit(void) {}
+static inline int thermal_generate_netlink_event(struct thermal_zone_device *tz,
+						 enum events event) { return -ENODEV; }
 #endif /* !CONFIG_NET */
 
 static int thermal_pm_notify(struct notifier_block *nb,
@@ -1591,19 +1598,15 @@  static int __init thermal_init(void)
 	mutex_init(&poweroff_lock);
 	result = thermal_register_governors();
 	if (result)
-		goto error;
+		goto init_exit;
 
 	result = class_register(&thermal_class);
 	if (result)
 		goto unregister_governors;
 
-	result = genetlink_init();
-	if (result)
-		goto unregister_class;
-
 	result = of_parse_thermal_zones();
 	if (result)
-		goto exit_netlink;
+		goto exit_zone_parse;
 
 	result = register_pm_notifier(&thermal_pm_nb);
 	if (result)
@@ -1612,13 +1615,11 @@  static int __init thermal_init(void)
 
 	return 0;
 
-exit_netlink:
-	genetlink_exit();
-unregister_class:
+exit_zone_parse:
 	class_unregister(&thermal_class);
 unregister_governors:
 	thermal_unregister_governors();
-error:
+init_exit:
 	ida_destroy(&thermal_tz_ida);
 	ida_destroy(&thermal_cdev_ida);
 	mutex_destroy(&thermal_list_lock);
@@ -1626,4 +1627,10 @@  static int __init thermal_init(void)
 	mutex_destroy(&poweroff_lock);
 	return result;
 }
-fs_initcall(thermal_init);
+
+static int __init thermal_netlink_init(void)
+{
+	return genetlink_init();
+}
+core_initcall(thermal_init);
+fs_initcall(thermal_netlink_init);