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thermal/core: Split __thermal_cooling_device_register() into two functions

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In preparation for the upcoming changes separating OF and non-OF code,
split __thermal_cooling_device_register() into allocation and addition
phases.

This allows moving the device node assignment out of the core
initialization path.

This change is not a trivial split. The lifetime of the cooling device
is managed by the device core through put_device(), which triggers
thermal_release() to free all associated resources.

With the introduction of thermal_cooling_device_alloc(), the allocation
path must mirror what thermal_release() undoes. In contrast,
thermal_cooling_device_add() must not perform any rollback and relies
on put_device() for cleanup on error paths. This avoids both double
free and resource leaks.

As part of this rework, add the missing device_initialize() call when
allocating the cooling device.

Suggested-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@oss.qualcomm.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
[ rjw: Replace device_register() with device_add() ]
[ rjw: Rebase on top of previously applied material ]
Link: https://patch.msgid.link/20260505144447.2853933-1-daniel.lezcano@oss.qualcomm.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Daniel Lezcano
2026-05-05 16:44:47 +02:00
committed by Rafael J. Wysocki
parent cfb5dc0f60
commit 13f4e660a1
1 changed files with 99 additions and 70 deletions
Download Patch File Download Diff File Expand all files Collapse all files

169
drivers/thermal/thermal_core.c
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@@ -963,6 +963,101 @@ static void thermal_cdev_release(struct device *dev)
kfree(cdev);
}
static struct thermal_cooling_device *
thermal_cooling_device_alloc(const char *type, const struct thermal_cooling_device_ops *ops)
{
struct thermal_cooling_device *cdev;
int ret;
if (!ops || !ops->get_max_state || !ops->get_cur_state ||
!ops->set_cur_state)
return ERR_PTR(-EINVAL);
if (!thermal_class)
return ERR_PTR(-ENODEV);
cdev = kzalloc_obj(*cdev);
if (!cdev)
return ERR_PTR(-ENOMEM);
cdev->ops = ops;
ret = ida_alloc(&thermal_cdev_ida, GFP_KERNEL);
if (ret < 0)
goto out_kfree_cdev;
cdev->id = ret;
cdev->type = kstrdup_const(type ? type : "", GFP_KERNEL);
if (!cdev->type) {
ret = -ENOMEM;
goto out_ida_remove;
}
return cdev;
out_ida_remove:
ida_free(&thermal_cdev_ida, cdev->id);
out_kfree_cdev:
kfree(cdev);
return ERR_PTR(ret);
}
static int thermal_cooling_device_add(struct thermal_cooling_device *cdev, void *devdata)
{
unsigned long current_state;
int ret;
mutex_init(&cdev->lock);
INIT_LIST_HEAD(&cdev->thermal_instances);
cdev->updated = false;
cdev->device.class = thermal_class;
cdev->device.release = thermal_cdev_release;
device_initialize(&cdev->device);
cdev->devdata = devdata;
thermal_cooling_device_setup_sysfs(cdev);
ret = dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
if (ret)
goto out_put_device;
ret = cdev->ops->get_max_state(cdev, &cdev->max_state);
if (ret)
goto out_put_device;
/*
* The cooling device's current state is only needed for debug
* initialization below, so a failure to get it does not cause
* the entire cooling device initialization to fail. However,
* the debug will not work for the device if its initial state
* cannot be determined and drivers are responsible for ensuring
* that this will not happen.
*/
ret = cdev->ops->get_cur_state(cdev, &current_state);
if (ret)
current_state = ULONG_MAX;
ret = device_add(&cdev->device);
if (ret)
goto out_put_device;
if (current_state <= cdev->max_state)
thermal_debug_cdev_add(cdev, current_state);
thermal_cooling_device_init_complete(cdev);
return 0;
out_put_device:
/*
* The device core will release the memory via
* thermal_release() after put_device() is called in the error
* path
*/
put_device(&cdev->device);
return ret;
}
/**
* __thermal_cooling_device_register() - register a new thermal cooling device
* @np: a pointer to a device tree node.
@@ -985,85 +1080,19 @@ __thermal_cooling_device_register(struct device_node *np,
const struct thermal_cooling_device_ops *ops)
{
struct thermal_cooling_device *cdev;
unsigned long current_state;
int ret;
if (!ops || !ops->get_max_state || !ops->get_cur_state ||
!ops->set_cur_state)
return ERR_PTR(-EINVAL);
cdev = thermal_cooling_device_alloc(type, ops);
if (IS_ERR(cdev))
return cdev;
if (!thermal_class)
return ERR_PTR(-ENODEV);
cdev = kzalloc_obj(*cdev);
if (!cdev)
return ERR_PTR(-ENOMEM);
ret = ida_alloc(&thermal_cdev_ida, GFP_KERNEL);
if (ret < 0)
goto out_kfree_cdev;
cdev->id = ret;
cdev->type = kstrdup_const(type ? type : "", GFP_KERNEL);
if (!cdev->type) {
ret = -ENOMEM;
goto out_ida_remove;
}
mutex_init(&cdev->lock);
INIT_LIST_HEAD(&cdev->thermal_instances);
cdev->np = np;
cdev->ops = ops;
cdev->updated = false;
cdev->device.class = thermal_class;
cdev->device.release = thermal_cdev_release;
cdev->devdata = devdata;
ret = cdev->ops->get_max_state(cdev, &cdev->max_state);
ret = thermal_cooling_device_add(cdev, devdata);
if (ret)
goto out_cdev_type;
/*
* The cooling device's current state is only needed for debug
* initialization below, so a failure to get it does not cause
* the entire cooling device initialization to fail. However,
* the debug will not work for the device if its initial state
* cannot be determined and drivers are responsible for ensuring
* that this will not happen.
*/
ret = cdev->ops->get_cur_state(cdev, &current_state);
if (ret)
current_state = ULONG_MAX;
thermal_cooling_device_setup_sysfs(cdev);
ret = dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
if (ret)
goto out_cooling_dev;
ret = device_register(&cdev->device);
if (ret) {
/* thermal_release() handles rest of the cleanup */
put_device(&cdev->device);
return ERR_PTR(ret);
}
if (current_state <= cdev->max_state)
thermal_debug_cdev_add(cdev, current_state);
thermal_cooling_device_init_complete(cdev);
return cdev;
out_cooling_dev:
thermal_cooling_device_destroy_sysfs(cdev);
out_cdev_type:
kfree_const(cdev->type);
out_ida_remove:
ida_free(&thermal_cdev_ida, cdev->id);
out_kfree_cdev:
kfree(cdev);
return ERR_PTR(ret);
}
/**