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Subject[PATCH 02/31] cpufreq: Implement light weight ->target() routine
Date
This patch implements the new light weight prototype for target() routine. It
looks like this:

int target(struct cpufreq_policy *policy, unsigned int index);

CPUFreq core will call cpufreq_frequency_table_target() before calling this
routine and pass index to it.

This also marks target_old() interface as deprecated. So, that new drivers avoid
using it.

Cc: Andrew Lunn <andrew@lunn.ch>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: John Crispin <blogic@openwrt.org>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-cris-kernel@axis.com
Cc: Mikael Starvik <starvik@axis.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Sekhar Nori <nsekhar@ti.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: sparclinux@vger.kernel.org
Cc: Stephen Warren <swarren@nvidia.com>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
drivers/cpufreq/cpufreq.c | 55 +++++++++++++++++++++++++++++++++++++----------
include/linux/cpufreq.h | 4 +++-
2 files changed, 47 insertions(+), 12 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 1cbea5b..a897a70 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -47,6 +47,11 @@ static LIST_HEAD(cpufreq_policy_list);
static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor);
#endif

+static inline bool has_target(void)
+{
+ return cpufreq_driver->target || cpufreq_driver->target_old;
+}
+
/*
* cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure
* all cpufreq/hotplug/workqueue/etc related lock issues.
@@ -377,7 +382,7 @@ static int cpufreq_parse_governor(char *str_governor, unsigned int *policy,
*policy = CPUFREQ_POLICY_POWERSAVE;
err = 0;
}
- } else if (cpufreq_driver->target_old) {
+ } else if (has_target()) {
struct cpufreq_governor *t;

mutex_lock(&cpufreq_governor_mutex);
@@ -539,7 +544,7 @@ static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy,
ssize_t i = 0;
struct cpufreq_governor *t;

- if (!cpufreq_driver->target_old) {
+ if (!has_target()) {
i += sprintf(buf, "performance powersave");
goto out;
}
@@ -822,7 +827,7 @@ static int cpufreq_add_dev_interface(struct cpufreq_policy *policy,
if (ret)
goto err_out_kobj_put;
}
- if (cpufreq_driver->target_old) {
+ if (has_target()) {
ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
if (ret)
goto err_out_kobj_put;
@@ -871,10 +876,10 @@ static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy,
unsigned int cpu, struct device *dev,
bool frozen)
{
- int ret = 0, has_target = !!cpufreq_driver->target_old;
+ int ret = 0;
unsigned long flags;

- if (has_target) {
+ if (has_target()) {
ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
if (ret) {
pr_err("%s: Failed to stop governor\n", __func__);
@@ -893,7 +898,7 @@ static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy,

unlock_policy_rwsem_write(policy->cpu);

- if (has_target) {
+ if (has_target()) {
if ((ret = __cpufreq_governor(policy, CPUFREQ_GOV_START)) ||
(ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))) {
pr_err("%s: Failed to start governor\n", __func__);
@@ -1204,7 +1209,7 @@ static int __cpufreq_remove_dev(struct device *dev,
return -EINVAL;
}

- if (cpufreq_driver->target_old) {
+ if (has_target()) {
ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
if (ret) {
pr_err("%s: Failed to stop governor\n", __func__);
@@ -1244,7 +1249,7 @@ static int __cpufreq_remove_dev(struct device *dev,

/* If cpu is last user of policy, free policy */
if (cpus == 1) {
- if (cpufreq_driver->target_old) {
+ if (has_target()) {
ret = __cpufreq_governor(policy,
CPUFREQ_GOV_POLICY_EXIT);
if (ret) {
@@ -1282,7 +1287,7 @@ static int __cpufreq_remove_dev(struct device *dev,
if (!frozen)
cpufreq_policy_free(policy);
} else {
- if (cpufreq_driver->target_old) {
+ if (has_target()) {
if ((ret = __cpufreq_governor(policy, CPUFREQ_GOV_START)) ||
(ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))) {
pr_err("%s: Failed to start governor\n",
@@ -1646,11 +1651,39 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
policy->cpu, target_freq, relation, old_target_freq);

+ /*
+ * This might look like a redundant call as we are checking it again
+ * after finding index. But it is left intentionally for cases where
+ * exactly same freq is called again and so we can save on few function
+ * calls.
+ */
if (target_freq == policy->cur)
return 0;

if (cpufreq_driver->target_old)
retval = cpufreq_driver->target_old(policy, target_freq, relation);
+ else if (cpufreq_driver->target) {
+ struct cpufreq_frequency_table *freq_table;
+ int index;
+
+ freq_table = cpufreq_frequency_get_table(policy->cpu);
+ if (unlikely(!freq_table)) {
+ pr_err("%s: Unable to find freq_table\n", __func__);
+ return retval;
+ }
+
+ retval = cpufreq_frequency_table_target(policy, freq_table,
+ target_freq, relation, &index);
+ if (unlikely(retval)) {
+ pr_err("%s: Unable to find matching freq\n", __func__);
+ return retval;
+ }
+
+ if (freq_table[index].frequency == policy->cur)
+ return 0;
+
+ retval = cpufreq_driver->target(policy, index);
+ }

return retval;
}
@@ -1983,7 +2016,7 @@ int cpufreq_update_policy(unsigned int cpu)
pr_debug("Driver did not initialize current freq");
policy->cur = new_policy.cur;
} else {
- if (policy->cur != new_policy.cur && cpufreq_driver->target_old)
+ if (policy->cur != new_policy.cur && has_target())
cpufreq_out_of_sync(cpu, policy->cur,
new_policy.cur);
}
@@ -2058,7 +2091,7 @@ int cpufreq_register_driver(struct cpufreq_driver *driver_data)
return -ENODEV;

if (!driver_data || !driver_data->verify || !driver_data->init ||
- ((!driver_data->setpolicy) && (!driver_data->target_old)))
+ (!driver_data->setpolicy && !has_target()))
return -EINVAL;

pr_debug("trying to register driver %s\n", driver_data->name);
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 47adf32..7c2e35b 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -195,9 +195,11 @@ struct cpufreq_driver {

/* define one out of two */
int (*setpolicy) (struct cpufreq_policy *policy);
- int (*target_old) (struct cpufreq_policy *policy,
+ int (*target_old) (struct cpufreq_policy *policy, /* Deprecated */
unsigned int target_freq,
unsigned int relation);
+ int (*target) (struct cpufreq_policy *policy,
+ unsigned int index);

/* should be defined, if possible */
unsigned int (*get) (unsigned int cpu);
--
1.7.12.rc2.18.g61b472e


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