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authorLinus Torvalds <torvalds@linux-foundation.org>2021-03-12 12:28:03 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2021-03-12 12:28:03 -0800
commit3077f0279effe1422410dafdf3c14d5756f1239a (patch)
treea30b1410e30f4dccc7358ec70ca3b4e9e41decdf
parent344178334b0971a1ad5f36b76d7b739400e46ec6 (diff)
parent7180323227702b46677e51d0da71f452615efd8c (diff)
Merge tag 'pm-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fixes from Rafael Wysocki: "These fix an operating performance point (OPP) reference counting issue and three issues in ARM cpufreq drivers. Specifics: - Add a flag to mark OPPs that are not referenced by he OPP core any more to prevent OPPs from being freed prematurely by mistake (Beata Michalska). - Add ARM Vexpress platforms to the cpufreq-dt-platdev blacklist since the actual scaling of them is handled elsewhere (Sudeep Holla). - Fix a function return value check and a possible use-after-free in the qcom-hw cpufreq driver (Shawn Guo, Wei Yongjun)" * tag 'pm-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: opp: Don't drop extra references to OPPs accidentally cpufreq: blacklist Arm Vexpress platforms in cpufreq-dt-platdev cpufreq: qcom-hw: Fix return value check in qcom_cpufreq_hw_cpu_init() cpufreq: qcom-hw: fix dereferencing freed memory 'data'
-rw-r--r--drivers/cpufreq/cpufreq-dt-platdev.c2
-rw-r--r--drivers/cpufreq/qcom-cpufreq-hw.c6
-rw-r--r--drivers/opp/core.c48
-rw-r--r--drivers/opp/opp.h2
4 files changed, 32 insertions, 26 deletions
diff --git a/drivers/cpufreq/cpufreq-dt-platdev.c b/drivers/cpufreq/cpufreq-dt-platdev.c
index 3ba2f716fe97..5e07065ec22f 100644
--- a/drivers/cpufreq/cpufreq-dt-platdev.c
+++ b/drivers/cpufreq/cpufreq-dt-platdev.c
@@ -103,6 +103,8 @@ static const struct of_device_id whitelist[] __initconst = {
static const struct of_device_id blacklist[] __initconst = {
{ .compatible = "allwinner,sun50i-h6", },
+ { .compatible = "arm,vexpress", },
+
{ .compatible = "calxeda,highbank", },
{ .compatible = "calxeda,ecx-2000", },
diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
index d3c23447b892..f86859bf76f1 100644
--- a/drivers/cpufreq/qcom-cpufreq-hw.c
+++ b/drivers/cpufreq/qcom-cpufreq-hw.c
@@ -317,9 +317,9 @@ static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
}
base = ioremap(res->start, resource_size(res));
- if (IS_ERR(base)) {
+ if (!base) {
dev_err(dev, "failed to map resource %pR\n", res);
- ret = PTR_ERR(base);
+ ret = -ENOMEM;
goto release_region;
}
@@ -374,7 +374,7 @@ static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
error:
kfree(data);
unmap_base:
- iounmap(data->base);
+ iounmap(base);
release_region:
release_mem_region(res->start, resource_size(res));
return ret;
diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index c2689386a906..1556998425d5 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -1492,7 +1492,11 @@ static struct dev_pm_opp *_opp_get_next(struct opp_table *opp_table,
mutex_lock(&opp_table->lock);
list_for_each_entry(temp, &opp_table->opp_list, node) {
- if (dynamic == temp->dynamic) {
+ /*
+ * Refcount must be dropped only once for each OPP by OPP core,
+ * do that with help of "removed" flag.
+ */
+ if (!temp->removed && dynamic == temp->dynamic) {
opp = temp;
break;
}
@@ -1502,10 +1506,27 @@ static struct dev_pm_opp *_opp_get_next(struct opp_table *opp_table,
return opp;
}
-bool _opp_remove_all_static(struct opp_table *opp_table)
+/*
+ * Can't call dev_pm_opp_put() from under the lock as debugfs removal needs to
+ * happen lock less to avoid circular dependency issues. This routine must be
+ * called without the opp_table->lock held.
+ */
+static void _opp_remove_all(struct opp_table *opp_table, bool dynamic)
{
struct dev_pm_opp *opp;
+ while ((opp = _opp_get_next(opp_table, dynamic))) {
+ opp->removed = true;
+ dev_pm_opp_put(opp);
+
+ /* Drop the references taken by dev_pm_opp_add() */
+ if (dynamic)
+ dev_pm_opp_put_opp_table(opp_table);
+ }
+}
+
+bool _opp_remove_all_static(struct opp_table *opp_table)
+{
mutex_lock(&opp_table->lock);
if (!opp_table->parsed_static_opps) {
@@ -1520,13 +1541,7 @@ bool _opp_remove_all_static(struct opp_table *opp_table)
mutex_unlock(&opp_table->lock);
- /*
- * Can't remove the OPP from under the lock, debugfs removal needs to
- * happen lock less to avoid circular dependency issues.
- */
- while ((opp = _opp_get_next(opp_table, false)))
- dev_pm_opp_put(opp);
-
+ _opp_remove_all(opp_table, false);
return true;
}
@@ -1539,25 +1554,12 @@ bool _opp_remove_all_static(struct opp_table *opp_table)
void dev_pm_opp_remove_all_dynamic(struct device *dev)
{
struct opp_table *opp_table;
- struct dev_pm_opp *opp;
- int count = 0;
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table))
return;
- /*
- * Can't remove the OPP from under the lock, debugfs removal needs to
- * happen lock less to avoid circular dependency issues.
- */
- while ((opp = _opp_get_next(opp_table, true))) {
- dev_pm_opp_put(opp);
- count++;
- }
-
- /* Drop the references taken by dev_pm_opp_add() */
- while (count--)
- dev_pm_opp_put_opp_table(opp_table);
+ _opp_remove_all(opp_table, true);
/* Drop the reference taken by _find_opp_table() */
dev_pm_opp_put_opp_table(opp_table);
diff --git a/drivers/opp/opp.h b/drivers/opp/opp.h
index 50fb9dced3c5..407c3bfe51d9 100644
--- a/drivers/opp/opp.h
+++ b/drivers/opp/opp.h
@@ -56,6 +56,7 @@ extern struct list_head opp_tables, lazy_opp_tables;
* @dynamic: not-created from static DT entries.
* @turbo: true if turbo (boost) OPP
* @suspend: true if suspend OPP
+ * @removed: flag indicating that OPP's reference is dropped by OPP core.
* @pstate: Device's power domain's performance state.
* @rate: Frequency in hertz
* @level: Performance level
@@ -78,6 +79,7 @@ struct dev_pm_opp {
bool dynamic;
bool turbo;
bool suspend;
+ bool removed;
unsigned int pstate;
unsigned long rate;
unsigned int level;