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PM / OPP: optimize dev_pm_opp_set_rate() performance a bit

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In dev_pm_opp_set_rate(), _find_opp_table() is called 4 times: once by
_get_opp_clk(), once by dev_pm_opp_set_rate() itself, and twice by
dev_pm_opp_find_freq_ceil(). If there are several opp_tables in the
system, three times of opp table finding is a big waste. This patch
reduced the call of _find_opp_table() to twice.

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Jisheng Zhang 2016-07-25 14:11:16 +08:00 committed by Rafael J. Wysocki
parent 523d939ef9
commit 067b7ce083
1 changed files with 19 additions and 12 deletions
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31
drivers/base/power/opp/core.c
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@ -402,6 +402,22 @@ struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,
} }
EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_exact); EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_exact);
static noinline struct dev_pm_opp *_find_freq_ceil(struct opp_table *opp_table,
unsigned long *freq)
{
struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
list_for_each_entry_rcu(temp_opp, &opp_table->opp_list, node) {
if (temp_opp->available && temp_opp->rate >= *freq) {
opp = temp_opp;
*freq = opp->rate;
break;
}
}
return opp;
}
/** /**
* dev_pm_opp_find_freq_ceil() - Search for an rounded ceil freq * dev_pm_opp_find_freq_ceil() - Search for an rounded ceil freq
* @dev: device for which we do this operation * @dev: device for which we do this operation
@ -427,7 +443,6 @@ struct dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev,
unsigned long *freq) unsigned long *freq)
{ {
struct opp_table *opp_table; struct opp_table *opp_table;
struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
opp_rcu_lockdep_assert(); opp_rcu_lockdep_assert();
@ -440,15 +455,7 @@ struct dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev,
if (IS_ERR(opp_table)) if (IS_ERR(opp_table))
return ERR_CAST(opp_table); return ERR_CAST(opp_table);
list_for_each_entry_rcu(temp_opp, &opp_table->opp_list, node) { return _find_freq_ceil(opp_table, freq);
if (temp_opp->available && temp_opp->rate >= *freq) {
opp = temp_opp;
*freq = opp->rate;
break;
}
}
return opp;
} }
EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_ceil); EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_ceil);
@ -612,7 +619,7 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
return PTR_ERR(opp_table); return PTR_ERR(opp_table);
} }
old_opp = dev_pm_opp_find_freq_ceil(dev, &old_freq); old_opp = _find_freq_ceil(opp_table, &old_freq);
if (!IS_ERR(old_opp)) { if (!IS_ERR(old_opp)) {
ou_volt = old_opp->u_volt; ou_volt = old_opp->u_volt;
ou_volt_min = old_opp->u_volt_min; ou_volt_min = old_opp->u_volt_min;
@ -622,7 +629,7 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
__func__, old_freq, PTR_ERR(old_opp)); __func__, old_freq, PTR_ERR(old_opp));
} }
opp = dev_pm_opp_find_freq_ceil(dev, &freq); opp = _find_freq_ceil(opp_table, &freq);
if (IS_ERR(opp)) { if (IS_ERR(opp)) {
ret = PTR_ERR(opp); ret = PTR_ERR(opp);
dev_err(dev, "%s: failed to find OPP for freq %lu (%d)\n", dev_err(dev, "%s: failed to find OPP for freq %lu (%d)\n",