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From 4a17bbfcf72c94b37079e39a7c1e1e8653f7fe92 Mon Sep 17 00:00:00 2001
From: Stephen Boyd <sboyd@codeaurora.org>
Date: Fri, 18 Sep 2015 17:52:07 -0700
Subject: [PATCH 50/69] 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>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
---
drivers/base/power/opp/core.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)
--- a/drivers/base/power/opp/core.c
+++ b/drivers/base/power/opp/core.c
@@ -32,9 +32,10 @@ LIST_HEAD(opp_tables);
/* Lock to allow exclusive modification to the device and opp lists */
DEFINE_MUTEX(opp_table_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(&opp_table_lock), \
"Missing rcu_read_lock() or " \
"opp_table_lock protection"); \
@@ -72,7 +73,7 @@ struct opp_table *_find_opp_table(struct
{
struct opp_table *opp_table;
- opp_rcu_lockdep_assert();
+ opp_rcu_lockdep_assert(NULL);
if (IS_ERR_OR_NULL(dev)) {
pr_err("%s: Invalid parameters\n", __func__);
@@ -106,7 +107,7 @@ unsigned long dev_pm_opp_get_voltage(str
struct dev_pm_opp *tmp_opp;
unsigned long v = 0;
- opp_rcu_lockdep_assert();
+ opp_rcu_lockdep_assert(NULL);
tmp_opp = rcu_dereference(opp);
if (IS_ERR_OR_NULL(tmp_opp))
@@ -138,7 +139,7 @@ unsigned long dev_pm_opp_get_freq(struct
struct dev_pm_opp *tmp_opp;
unsigned long f = 0;
- opp_rcu_lockdep_assert();
+ opp_rcu_lockdep_assert(NULL);
tmp_opp = rcu_dereference(opp);
if (IS_ERR_OR_NULL(tmp_opp) || !tmp_opp->available)
@@ -172,7 +173,7 @@ bool dev_pm_opp_is_turbo(struct dev_pm_o
{
struct dev_pm_opp *tmp_opp;
- opp_rcu_lockdep_assert();
+ opp_rcu_lockdep_assert(NULL);
tmp_opp = rcu_dereference(opp);
if (IS_ERR_OR_NULL(tmp_opp) || !tmp_opp->available) {
@@ -300,7 +301,7 @@ struct dev_pm_opp *dev_pm_opp_get_suspen
{
struct opp_table *opp_table;
- opp_rcu_lockdep_assert();
+ opp_rcu_lockdep_assert(NULL);
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table) || !opp_table->suspend_opp ||
@@ -380,7 +381,7 @@ struct dev_pm_opp *dev_pm_opp_find_freq_
struct opp_table *opp_table;
struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
- opp_rcu_lockdep_assert();
+ opp_rcu_lockdep_assert(NULL);
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table)) {
@@ -444,7 +445,7 @@ struct dev_pm_opp *dev_pm_opp_find_freq_
{
struct opp_table *opp_table;
- opp_rcu_lockdep_assert();
+ opp_rcu_lockdep_assert(NULL);
if (!dev || !freq) {
dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq);
@@ -486,7 +487,7 @@ struct dev_pm_opp *dev_pm_opp_find_freq_
struct opp_table *opp_table;
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);
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