diff options
| author | Stephen Boyd <sboyd@codeaurora.org> | 2015-06-01 18:47:57 -0700 |
|---|---|---|
| committer | Srinivas Kandagatla <srinivas.kandagatla@linaro.org> | 2015-11-17 17:59:02 +0000 |
| commit | 48e38a397a0134602ae550a982133c19365a6733 (patch) | |
| tree | f01bf48fbdbedf6ed36be3d34abeeb6696004a51 | |
| parent | b457a8762e06b5153dc0e1f5f457c2c5921178f0 (diff) | |
| download | linux-linaro-tracking-48e38a397a0134602ae550a982133c19365a6733.tar.gz | |
OPP: Allow notifiers to call dev_pm_opp_get_{voltage, freq} RCU-free
We pass the dev_pm_opp structure to OPP notifiers but the users
of the notifier need to surround calls to dev_pm_opp_get_*() with
RCU read locks to avoid lockdep warnings. The notifier is already
called with the dev_opp's srcu lock held, so it should be safe to
assume the devm_pm_opp structure is already protected inside the
notifier. Update the lockdep check for this.
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
| -rw-r--r-- | drivers/base/power/opp.c | 23 |
1 files changed, 13 insertions, 10 deletions
diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c index 0805dc02db6a..c2afba212539 100644 --- a/drivers/base/power/opp.c +++ b/drivers/base/power/opp.c @@ -146,9 +146,10 @@ static LIST_HEAD(dev_opp_list); /* Lock to allow exclusive modification to the device and opp lists */ static DEFINE_MUTEX(dev_opp_list_lock); -#define opp_rcu_lockdep_assert() \ +#define opp_rcu_lockdep_assert(s) \ do { \ RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \ + !(s && srcu_read_lock_held(s)) && \ !lockdep_is_held(&dev_opp_list_lock), \ "Missing rcu_read_lock() or " \ "dev_opp_list_lock protection"); \ @@ -236,9 +237,10 @@ unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp) struct dev_pm_opp *tmp_opp; unsigned long v = 0; - opp_rcu_lockdep_assert(); + opp_rcu_lockdep_assert(&opp->dev_opp->srcu_head.srcu); - tmp_opp = rcu_dereference(opp); + tmp_opp = srcu_dereference_check(opp, &opp->dev_opp->srcu_head.srcu, + rcu_read_lock_held()); if (IS_ERR_OR_NULL(tmp_opp) || !tmp_opp->available) pr_err("%s: Invalid parameters\n", __func__); else @@ -268,9 +270,10 @@ unsigned long dev_pm_opp_get_freq(struct dev_pm_opp *opp) struct dev_pm_opp *tmp_opp; unsigned long f = 0; - opp_rcu_lockdep_assert(); + opp_rcu_lockdep_assert(&opp->dev_opp->srcu_head.srcu); - tmp_opp = rcu_dereference(opp); + tmp_opp = srcu_dereference_check(opp, &opp->dev_opp->srcu_head.srcu, + rcu_read_lock_held()); if (IS_ERR_OR_NULL(tmp_opp) || !tmp_opp->available) pr_err("%s: Invalid parameters\n", __func__); else @@ -302,7 +305,7 @@ bool dev_pm_opp_is_turbo(struct dev_pm_opp *opp) { struct dev_pm_opp *tmp_opp; - opp_rcu_lockdep_assert(); + opp_rcu_lockdep_assert(&opp->dev_opp->srcu_head.srcu); tmp_opp = rcu_dereference(opp); if (IS_ERR_OR_NULL(tmp_opp) || !tmp_opp->available) { @@ -357,7 +360,7 @@ struct dev_pm_opp *dev_pm_opp_get_suspend_opp(struct device *dev) { struct device_opp *dev_opp; - opp_rcu_lockdep_assert(); + opp_rcu_lockdep_assert(NULL); dev_opp = _find_device_opp(dev); if (IS_ERR(dev_opp) || !dev_opp->suspend_opp || @@ -437,7 +440,7 @@ struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev, struct device_opp *dev_opp; struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE); - opp_rcu_lockdep_assert(); + opp_rcu_lockdep_assert(NULL); dev_opp = _find_device_opp(dev); if (IS_ERR(dev_opp)) { @@ -485,7 +488,7 @@ struct dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev, struct device_opp *dev_opp; struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE); - opp_rcu_lockdep_assert(); + opp_rcu_lockdep_assert(NULL); if (!dev || !freq) { dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq); @@ -535,7 +538,7 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev, struct device_opp *dev_opp; struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE); - opp_rcu_lockdep_assert(); + opp_rcu_lockdep_assert(NULL); if (!dev || !freq) { dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq); |