[PATCH 06/28] PM: QoS: Drop iterations over global QoS classes

Rafael J. Wysocki
2020-02-11T23:39:30Z

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

After commit c3082a674f46 ("PM: QoS: Get rid of unused flags") the
only global PM QoS class in use is PM_QOS_CPU_DMA_LATENCY, so it
does not really make sense to iterate over global QoS classes
anywhere, since there is only one.

Remove iterations over global QoS classes from the code and use
PM_QOS_CPU_DMA_LATENCY as the target class directly where needed.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
kernel/power/qos.c | 52 ++++++++++++++--------------------------------------
1 file changed, 14 insertions(+), 38 deletions(-)

diff --git a/kernel/power/qos.c b/kernel/power/qos.c
index f09eca5ffe07..57ff542a4f9d 100644
--- a/kernel/power/qos.c
+++ b/kernel/power/qos.c
@@ -412,7 +412,8 @@ int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier)
}
EXPORT_SYMBOL_GPL(pm_qos_remove_notifier);

-/* User space interface to PM QoS classes via misc devices */
+/* User space interface to global PM QoS via misc device. */
+
static int register_pm_qos_misc(struct pm_qos_object *qos)
{
qos->pm_qos_power_miscdev.minor = MISC_DYNAMIC_MINOR;
@@ -422,35 +423,18 @@ static int register_pm_qos_misc(struct pm_qos_object *qos)
return misc_register(&qos->pm_qos_power_miscdev);
}

-static int find_pm_qos_object_by_minor(int minor)
-{
- int pm_qos_class;
-
- for (pm_qos_class = PM_QOS_CPU_DMA_LATENCY;
- pm_qos_class < PM_QOS_NUM_CLASSES; pm_qos_class++) {
- if (minor ==
- pm_qos_array[pm_qos_class]->pm_qos_power_miscdev.minor)
- return pm_qos_class;
- }
- return -1;
-}
-
static int pm_qos_power_open(struct inode *inode, struct file *filp)
{
- long pm_qos_class;
+ struct pm_qos_request *req;

- pm_qos_class = find_pm_qos_object_by_minor(iminor(inode));
- if (pm_qos_class >= PM_QOS_CPU_DMA_LATENCY) {
- struct pm_qos_request *req = kzalloc(sizeof(*req), GFP_KERNEL);
- if (!req)
- return -ENOMEM;
+ req = kzalloc(sizeof(*req), GFP_KERNEL);
+ if (!req)
+ return -ENOMEM;

- pm_qos_add_request(req, pm_qos_class, PM_QOS_DEFAULT_VALUE);
- filp->private_data = req;
+ pm_qos_add_request(req, PM_QOS_CPU_DMA_LATENCY, PM_QOS_DEFAULT_VALUE);
+ filp->private_data = req;

- return 0;
- }
- return -EPERM;
+ return 0;
}

static int pm_qos_power_release(struct inode *inode, struct file *filp)
@@ -464,7 +448,6 @@ static int pm_qos_power_release(struct inode *inode, struct file *filp)
return 0;
}

-
static ssize_t pm_qos_power_read(struct file *filp, char __user *buf,
size_t count, loff_t *f_pos)
{
@@ -507,26 +490,19 @@ static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf,
return count;
}

-
static int __init pm_qos_power_init(void)
{
- int ret = 0;
- int i;
+ int ret;

BUILD_BUG_ON(ARRAY_SIZE(pm_qos_array) != PM_QOS_NUM_CLASSES);

- for (i = PM_QOS_CPU_DMA_LATENCY; i < PM_QOS_NUM_CLASSES; i++) {
- ret = register_pm_qos_misc(pm_qos_array[i]);
- if (ret < 0) {
- pr_err("%s: %s setup failed\n",
- __func__, pm_qos_array[i]->name);
- return ret;
- }
- }
+ ret = register_pm_qos_misc(pm_qos_array[PM_QOS_CPU_DMA_LATENCY]);
+ if (ret < 0)
+ pr_err("%s: %s setup failed\n", __func__,
+ pm_qos_array[PM_QOS_CPU_DMA_LATENCY]->name);

return ret;
}
-
late_initcall(pm_qos_power_init);

/* Definitions related to the frequency QoS below. */
--
2.16.4