[PATCH AUTOSEL 4.19 145/671] driver core: Fix handling of runtime PM flags in device_link_add()

[PATCH AUTOSEL 4.19 145/671] driver core: Fix handling of runtime PM flags in device_link_add()

[Sasha Levin]

From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>

[ Upstream commit e2f3cd831a280fc226118d9369bf3f77aab58c56 ]

After commit ead18c23c263 ("driver core: Introduce device links
reference counting"), if there is a link between the given supplier
and the given consumer already, device_link_add() will refcount it
and return it unconditionally without updating its flags.  It is
possible, however, that the second (or any subsequent) caller of
device_link_add() for the same consumer-supplier pair will pass
DL_FLAG_PM_RUNTIME, possibly along with DL_FLAG_RPM_ACTIVE, in flags
to it and the existing link may not behave as expected then.

First, if DL_FLAG_PM_RUNTIME is not set in the existing link's flags
at all, it needs to be set like during the original initialization of
the link.

Second, if DL_FLAG_RPM_ACTIVE is passed to device_link_add() in flags
(in addition to DL_FLAG_PM_RUNTIME), the existing link should to be
updated to reflect the "active" runtime PM configuration of the
consumer-supplier pair and extra care must be taken here to avoid
possible destructive races with runtime PM of the consumer.

To that end, redefine the rpm_active field in struct device_link
as a refcount, initialize it to 1 and make rpm_resume() (for the
consumer) and device_link_add() increment it whenever they acquire
a runtime PM reference on the supplier device.  Accordingly, make
rpm_suspend() (for the consumer) and pm_runtime_clean_up_links()
decrement it and drop runtime PM references to the supplier
device in a loop until rpm_active becones 1 again.

Fixes: ead18c23c263 ("driver core: Introduce device links reference counting")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/base/core.c          | 45 ++++++++++++++++++++++++------------
 drivers/base/power/runtime.c | 26 +++++++++------------
 include/linux/device.h       |  2 +-
 3 files changed, 42 insertions(+), 31 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index c228b4ebf554..20ae18f44dcd 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -165,6 +165,19 @@ void device_pm_move_to_tail(struct device *dev)
 	device_links_read_unlock(idx);
 }
 
+static void device_link_rpm_prepare(struct device *consumer,
+				    struct device *supplier)
+{
+	pm_runtime_new_link(consumer);
+	/*
+	 * If the link is being added by the consumer driver at probe time,
+	 * balance the decrementation of the supplier's runtime PM usage counter
+	 * after consumer probe in driver_probe_device().
+	 */
+	if (consumer->links.status == DL_DEV_PROBING)
+		pm_runtime_get_noresume(supplier);
+}
+
 /**
  * device_link_add - Create a link between two devices.
  * @consumer: Consumer end of the link.
@@ -201,7 +214,6 @@ struct device_link *device_link_add(struct device *consumer,
 				    struct device *supplier, u32 flags)
 {
 	struct device_link *link;
-	bool rpm_put_supplier = false;
 
 	if (!consumer || !supplier ||
 	    (flags & DL_FLAG_STATELESS &&
@@ -213,7 +225,6 @@ struct device_link *device_link_add(struct device *consumer,
 			pm_runtime_put_noidle(supplier);
 			return NULL;
 		}
-		rpm_put_supplier = true;
 	}
 
 	device_links_write_lock();
@@ -249,6 +260,15 @@ struct device_link *device_link_add(struct device *consumer,
 		if (flags & DL_FLAG_AUTOREMOVE_SUPPLIER)
 			link->flags |= DL_FLAG_AUTOREMOVE_SUPPLIER;
 
+		if (flags & DL_FLAG_PM_RUNTIME) {
+			if (!(link->flags & DL_FLAG_PM_RUNTIME)) {
+				device_link_rpm_prepare(consumer, supplier);
+				link->flags |= DL_FLAG_PM_RUNTIME;
+			}
+			if (flags & DL_FLAG_RPM_ACTIVE)
+				refcount_inc(&link->rpm_active);
+		}
+
 		kref_get(&link->kref);
 		goto out;
 	}
@@ -257,20 +277,15 @@ struct device_link *device_link_add(struct device *consumer,
 	if (!link)
 		goto out;
 
+	refcount_set(&link->rpm_active, 1);
+
 	if (flags & DL_FLAG_PM_RUNTIME) {
-		if (flags & DL_FLAG_RPM_ACTIVE) {
-			link->rpm_active = true;
-			rpm_put_supplier = false;
-		}
-		pm_runtime_new_link(consumer);
-		/*
-		 * If the link is being added by the consumer driver at probe
-		 * time, balance the decrementation of the supplier's runtime PM
-		 * usage counter after consumer probe in driver_probe_device().
-		 */
-		if (consumer->links.status == DL_DEV_PROBING)
-			pm_runtime_get_noresume(supplier);
+		if (flags & DL_FLAG_RPM_ACTIVE)
+			refcount_inc(&link->rpm_active);
+
+		device_link_rpm_prepare(consumer, supplier);
 	}
+
 	get_device(supplier);
 	link->supplier = supplier;
 	INIT_LIST_HEAD(&link->s_node);
@@ -333,7 +348,7 @@ struct device_link *device_link_add(struct device *consumer,
 	device_pm_unlock();
 	device_links_write_unlock();
 
-	if (rpm_put_supplier)
+	if ((flags & DL_FLAG_PM_RUNTIME && flags & DL_FLAG_RPM_ACTIVE) && !link)
 		pm_runtime_put(supplier);
 
 	return link;
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index beb85c31f3fa..b914932d3ca1 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -268,11 +268,8 @@ static int rpm_get_suppliers(struct device *dev)
 	list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) {
 		int retval;
 
-		if (!(link->flags & DL_FLAG_PM_RUNTIME))
-			continue;
-
-		if (READ_ONCE(link->status) == DL_STATE_SUPPLIER_UNBIND ||
-		    link->rpm_active)
+		if (!(link->flags & DL_FLAG_PM_RUNTIME) ||
+		    READ_ONCE(link->status) == DL_STATE_SUPPLIER_UNBIND)
 			continue;
 
 		retval = pm_runtime_get_sync(link->supplier);
@@ -281,7 +278,7 @@ static int rpm_get_suppliers(struct device *dev)
 			pm_runtime_put_noidle(link->supplier);
 			return retval;
 		}
-		link->rpm_active = true;
+		refcount_inc(&link->rpm_active);
 	}
 	return 0;
 }
@@ -290,12 +287,13 @@ static void rpm_put_suppliers(struct device *dev)
 {
 	struct device_link *link;
 
-	list_for_each_entry_rcu(link, &dev->links.suppliers, c_node)
-		if (link->rpm_active &&
-		    READ_ONCE(link->status) != DL_STATE_SUPPLIER_UNBIND) {
+	list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) {
+		if (READ_ONCE(link->status) == DL_STATE_SUPPLIER_UNBIND)
+			continue;
+
+		while (refcount_dec_not_one(&link->rpm_active))
 			pm_runtime_put(link->supplier);
-			link->rpm_active = false;
-		}
+	}
 }
 
 /**
@@ -1531,7 +1529,7 @@ void pm_runtime_remove(struct device *dev)
  *
  * Check links from this device to any consumers and if any of them have active
  * runtime PM references to the device, drop the usage counter of the device
- * (once per link).
+ * (as many times as needed).
  *
  * Links with the DL_FLAG_STATELESS flag set are ignored.
  *
@@ -1553,10 +1551,8 @@ void pm_runtime_clean_up_links(struct device *dev)
 		if (link->flags & DL_FLAG_STATELESS)
 			continue;
 
-		if (link->rpm_active) {
+		while (refcount_dec_not_one(&link->rpm_active))
 			pm_runtime_put_noidle(dev);
-			link->rpm_active = false;
-		}
 	}
 
 	device_links_read_unlock(idx);
diff --git a/include/linux/device.h b/include/linux/device.h
index 19dd8852602c..b8fd2a1f859d 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -849,7 +849,7 @@ struct device_link {
 	struct list_head c_node;
 	enum device_link_state status;
 	u32 flags;
-	bool rpm_active;
+	refcount_t rpm_active;
 	struct kref kref;
 #ifdef CONFIG_SRCU
 	struct rcu_head rcu_head;
-- 
2.20.1

[PATCH AUTOSEL 4.19 146/671] driver core: Do not call rpm_put_suppliers() in pm_runtime_drop_link()

[Sasha Levin]

From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>

[ Upstream commit a1fdbfbb1da2063ba98a12eb6f1bdd07451c7145 ]

Calling rpm_put_suppliers() from pm_runtime_drop_link() is excessive
as it affects all suppliers of the consumer device and not just the
one pointed to by the device link being dropped.  Worst case it may
cause the consumer device to stop working unexpectedly.  Moreover, in
principle it is racy with respect to runtime PM of the consumer
device.

To avoid these problems drop runtime PM references on the particular
supplier pointed to by the link in question only and do that after
the link has been dropped from the consumer device's list of links to
suppliers, which is in device_link_free().

Fixes: a0504aecba76 ("PM / runtime: Drop usage count for suppliers at device link removal")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/base/core.c          | 3 +++
 drivers/base/power/runtime.c | 2 --
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 20ae18f44dcd..7599147d5f83 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -357,6 +357,9 @@ EXPORT_SYMBOL_GPL(device_link_add);
 
 static void device_link_free(struct device_link *link)
 {
+	while (refcount_dec_not_one(&link->rpm_active))
+		pm_runtime_put(link->supplier);
+
 	put_device(link->consumer);
 	put_device(link->supplier);
 	kfree(link);
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index b914932d3ca1..ab454c4533ba 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -1603,8 +1603,6 @@ void pm_runtime_new_link(struct device *dev)
 
 void pm_runtime_drop_link(struct device *dev)
 {
-	rpm_put_suppliers(dev);
-
 	spin_lock_irq(&dev->power.lock);
 	WARN_ON(dev->power.links_count == 0);
 	dev->power.links_count--;
-- 
2.20.1

[PATCH AUTOSEL 4.19 157/671] thermal: mediatek: fix register index error

[Sasha Levin]

From: Michael Kao <michael.kao@mediatek.com>

[ Upstream commit eb9aecd90d1a39601e91cd08b90d5fee51d321a6 ]

The index of msr and adcpnp should match the sensor
which belongs to the selected bank in the for loop.

Fixes: b7cf0053738c ("thermal: Add Mediatek thermal driver for mt2701.")
Signed-off-by: Michael Kao <michael.kao@mediatek.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/thermal/mtk_thermal.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/thermal/mtk_thermal.c b/drivers/thermal/mtk_thermal.c
index 0691f260f6ea..f64643629d8b 100644
--- a/drivers/thermal/mtk_thermal.c
+++ b/drivers/thermal/mtk_thermal.c
@@ -431,7 +431,8 @@ static int mtk_thermal_bank_temperature(struct mtk_thermal_bank *bank)
 	u32 raw;
 
 	for (i = 0; i < conf->bank_data[bank->id].num_sensors; i++) {
-		raw = readl(mt->thermal_base + conf->msr[i]);
+		raw = readl(mt->thermal_base +
+			    conf->msr[conf->bank_data[bank->id].sensors[i]]);
 
 		temp = raw_to_mcelsius(mt,
 				       conf->bank_data[bank->id].sensors[i],
@@ -568,7 +569,8 @@ static void mtk_thermal_init_bank(struct mtk_thermal *mt, int num,
 
 	for (i = 0; i < conf->bank_data[num].num_sensors; i++)
 		writel(conf->sensor_mux_values[conf->bank_data[num].sensors[i]],
-		       mt->thermal_base + conf->adcpnp[i]);
+		       mt->thermal_base +
+		       conf->adcpnp[conf->bank_data[num].sensors[i]]);
 
 	writel((1 << conf->bank_data[num].num_sensors) - 1,
 	       mt->thermal_base + TEMP_MONCTL0);
-- 
2.20.1

[PATCH AUTOSEL 4.19 179/671] driver core: Fix possible supplier PM-usage counter imbalance

[Sasha Levin]

From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>

[ Upstream commit 4c06c4e6cf63d7f3d5dfe62593a073253d750a59 ]

If a stateless device link to a certain supplier with
DL_FLAG_PM_RUNTIME set in the flags is added and then removed by the
consumer driver's probe callback, the supplier's PM-runtime usage
counter will be nonzero after that which effectively causes the
supplier to remain "always on" going forward.

Namely, device_link_add() called to add the link invokes
device_link_rpm_prepare() which notices that the consumer driver is
probing, so it increments the supplier's PM-runtime usage counter
with the assumption that the link will stay around until
pm_runtime_put_suppliers() is called by driver_probe_device(),
but if the link goes away before that point, the supplier's
PM-runtime usage counter will remain nonzero.

To prevent that from happening, first rework pm_runtime_get_suppliers()
and pm_runtime_put_suppliers() to use the rpm_active refounts of device
links and make the latter only drop rpm_active and the supplier's
PM-runtime usage counter for each link by one, unless rpm_active is
one already for it.  Next, modify device_link_add() to bump up the
new link's rpm_active refcount and the suppliers PM-runtime usage
counter by two, to prevent pm_runtime_put_suppliers(), if it is
called subsequently, from suspending the supplier prematurely (in
case its PM-runtime usage counter goes down to 0 in there).

Due to the way rpm_put_suppliers() works, this change does not
affect runtime suspend of the consumer ends of new device links (or,
generally, device links for which DL_FLAG_PM_RUNTIME has just been
set).

Fixes: e2f3cd831a28 ("driver core: Fix handling of runtime PM flags in device_link_add()")
Reported-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/base/core.c          | 21 ++++-----------------
 drivers/base/power/runtime.c | 27 +++++++++++++++++++++++++--
 include/linux/pm_runtime.h   |  4 ++++
 3 files changed, 33 insertions(+), 19 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 7599147d5f83..ab08211ba5d2 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -165,19 +165,6 @@ void device_pm_move_to_tail(struct device *dev)
 	device_links_read_unlock(idx);
 }
 
-static void device_link_rpm_prepare(struct device *consumer,
-				    struct device *supplier)
-{
-	pm_runtime_new_link(consumer);
-	/*
-	 * If the link is being added by the consumer driver at probe time,
-	 * balance the decrementation of the supplier's runtime PM usage counter
-	 * after consumer probe in driver_probe_device().
-	 */
-	if (consumer->links.status == DL_DEV_PROBING)
-		pm_runtime_get_noresume(supplier);
-}
-
 /**
  * device_link_add - Create a link between two devices.
  * @consumer: Consumer end of the link.
@@ -262,11 +249,11 @@ struct device_link *device_link_add(struct device *consumer,
 
 		if (flags & DL_FLAG_PM_RUNTIME) {
 			if (!(link->flags & DL_FLAG_PM_RUNTIME)) {
-				device_link_rpm_prepare(consumer, supplier);
+				pm_runtime_new_link(consumer);
 				link->flags |= DL_FLAG_PM_RUNTIME;
 			}
 			if (flags & DL_FLAG_RPM_ACTIVE)
-				refcount_inc(&link->rpm_active);
+				pm_runtime_active_link(link, supplier);
 		}
 
 		kref_get(&link->kref);
@@ -281,9 +268,9 @@ struct device_link *device_link_add(struct device *consumer,
 
 	if (flags & DL_FLAG_PM_RUNTIME) {
 		if (flags & DL_FLAG_RPM_ACTIVE)
-			refcount_inc(&link->rpm_active);
+			pm_runtime_active_link(link, supplier);
 
-		device_link_rpm_prepare(consumer, supplier);
+		pm_runtime_new_link(consumer);
 	}
 
 	get_device(supplier);
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index ab454c4533ba..0527890b4c19 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -1570,8 +1570,10 @@ void pm_runtime_get_suppliers(struct device *dev)
 	idx = device_links_read_lock();
 
 	list_for_each_entry_rcu(link, &dev->links.suppliers, c_node)
-		if (link->flags & DL_FLAG_PM_RUNTIME)
+		if (link->flags & DL_FLAG_PM_RUNTIME) {
+			refcount_inc(&link->rpm_active);
 			pm_runtime_get_sync(link->supplier);
+		}
 
 	device_links_read_unlock(idx);
 }
@@ -1588,7 +1590,8 @@ void pm_runtime_put_suppliers(struct device *dev)
 	idx = device_links_read_lock();
 
 	list_for_each_entry_rcu(link, &dev->links.suppliers, c_node)
-		if (link->flags & DL_FLAG_PM_RUNTIME)
+		if (link->flags & DL_FLAG_PM_RUNTIME &&
+		    refcount_dec_not_one(&link->rpm_active))
 			pm_runtime_put(link->supplier);
 
 	device_links_read_unlock(idx);
@@ -1601,6 +1604,26 @@ void pm_runtime_new_link(struct device *dev)
 	spin_unlock_irq(&dev->power.lock);
 }
 
+/**
+ * pm_runtime_active_link - Set up new device link as active for PM-runtime.
+ * @link: Device link to be set up as active.
+ * @supplier: Supplier end of the link.
+ *
+ * Add 2 to the rpm_active refcount of @link and increment the PM-runtime
+ * usage counter of @supplier once more in case the link is being added while
+ * the consumer driver is probing and pm_runtime_put_suppliers() will be called
+ * subsequently.
+ *
+ * Note that this doesn't prevent rpm_put_suppliers() from decreasing the link's
+ * rpm_active refcount down to one, so runtime suspend of the consumer end of
+ * @link is not affected.
+ */
+void pm_runtime_active_link(struct device_link *link, struct device *supplier)
+{
+	refcount_add(2, &link->rpm_active);
+	pm_runtime_get_noresume(supplier);
+}
+
 void pm_runtime_drop_link(struct device *dev)
 {
 	spin_lock_irq(&dev->power.lock);
diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h
index f0fc4700b6ff..bace7df51af4 100644
--- a/include/linux/pm_runtime.h
+++ b/include/linux/pm_runtime.h
@@ -59,6 +59,8 @@ extern void pm_runtime_clean_up_links(struct device *dev);
 extern void pm_runtime_get_suppliers(struct device *dev);
 extern void pm_runtime_put_suppliers(struct device *dev);
 extern void pm_runtime_new_link(struct device *dev);
+extern void pm_runtime_active_link(struct device_link *link,
+				   struct device *supplier);
 extern void pm_runtime_drop_link(struct device *dev);
 
 static inline void pm_suspend_ignore_children(struct device *dev, bool enable)
@@ -176,6 +178,8 @@ static inline void pm_runtime_clean_up_links(struct device *dev) {}
 static inline void pm_runtime_get_suppliers(struct device *dev) {}
 static inline void pm_runtime_put_suppliers(struct device *dev) {}
 static inline void pm_runtime_new_link(struct device *dev) {}
+static inline void pm_runtime_active_link(struct device_link *link,
+					  struct device *supplier) {}
 static inline void pm_runtime_drop_link(struct device *dev) {}
 
 #endif /* !CONFIG_PM */
-- 
2.20.1

[PATCH AUTOSEL 4.19 205/671] driver core: Fix PM-runtime for links added during consumer probe

[Sasha Levin]

From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>

[ Upstream commit 36003d4cf57ca431fb3f94d317bcca426a2394d6 ]

Commit 4c06c4e6cf63 ("driver core: Fix possible supplier PM-usage
counter imbalance") introduced a regression that causes suppliers
to be suspended prematurely for device links added during consumer
driver probe if the initial PM-runtime status of the consumer is
"suspended" and the consumer is resumed after adding the link and
before pm_runtime_put_suppliers() is called.  In that case,
pm_runtime_put_suppliers() will drop the rpm_active refcount for
the link by one and (since rpm_active is equal to two after the
preceding consumer resume) the supplier's PM-runtime usage counter
will be decremented, which may cause the supplier to suspend even
though the consumer's PM-runtime status is "active".

For this reason, partially revert commit 4c06c4e6cf63 as the problem
it tried to fix needs to be addressed somewhat differently, and
change pm_runtime_get_suppliers() and pm_runtime_put_suppliers() so
that the latter only drops rpm_active references acquired by the
former.  [This requires adding a new field to struct device_link,
but I coulnd't find a cleaner way to address the issue that would
work in all cases.]

This causes pm_runtime_put_suppliers() to effectively ignore device
links added during consumer probe, so device_link_add() doesn't need
to worry about ensuring that suppliers will remain active after
pm_runtime_put_suppliers() for links created with DL_FLAG_RPM_ACTIVE
set and it only needs to bump up rpm_active by one for those links,
so pm_runtime_active_link() is not necessary any more.

Fixes: 4c06c4e6cf63 ("driver core: Fix possible supplier PM-usage counter imbalance")
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/base/core.c          |  4 ++--
 drivers/base/power/runtime.c | 29 ++++++-----------------------
 include/linux/device.h       |  1 +
 include/linux/pm_runtime.h   |  4 ----
 4 files changed, 9 insertions(+), 29 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index ab08211ba5d2..742bc60e9cca 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -253,7 +253,7 @@ struct device_link *device_link_add(struct device *consumer,
 				link->flags |= DL_FLAG_PM_RUNTIME;
 			}
 			if (flags & DL_FLAG_RPM_ACTIVE)
-				pm_runtime_active_link(link, supplier);
+				refcount_inc(&link->rpm_active);
 		}
 
 		kref_get(&link->kref);
@@ -268,7 +268,7 @@ struct device_link *device_link_add(struct device *consumer,
 
 	if (flags & DL_FLAG_PM_RUNTIME) {
 		if (flags & DL_FLAG_RPM_ACTIVE)
-			pm_runtime_active_link(link, supplier);
+			refcount_inc(&link->rpm_active);
 
 		pm_runtime_new_link(consumer);
 	}
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 0527890b4c19..303ce7d54a30 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -1571,6 +1571,7 @@ void pm_runtime_get_suppliers(struct device *dev)
 
 	list_for_each_entry_rcu(link, &dev->links.suppliers, c_node)
 		if (link->flags & DL_FLAG_PM_RUNTIME) {
+			link->supplier_preactivated = true;
 			refcount_inc(&link->rpm_active);
 			pm_runtime_get_sync(link->supplier);
 		}
@@ -1590,9 +1591,11 @@ void pm_runtime_put_suppliers(struct device *dev)
 	idx = device_links_read_lock();
 
 	list_for_each_entry_rcu(link, &dev->links.suppliers, c_node)
-		if (link->flags & DL_FLAG_PM_RUNTIME &&
-		    refcount_dec_not_one(&link->rpm_active))
-			pm_runtime_put(link->supplier);
+		if (link->supplier_preactivated) {
+			link->supplier_preactivated = false;
+			if (refcount_dec_not_one(&link->rpm_active))
+				pm_runtime_put(link->supplier);
+		}
 
 	device_links_read_unlock(idx);
 }
@@ -1604,26 +1607,6 @@ void pm_runtime_new_link(struct device *dev)
 	spin_unlock_irq(&dev->power.lock);
 }
 
-/**
- * pm_runtime_active_link - Set up new device link as active for PM-runtime.
- * @link: Device link to be set up as active.
- * @supplier: Supplier end of the link.
- *
- * Add 2 to the rpm_active refcount of @link and increment the PM-runtime
- * usage counter of @supplier once more in case the link is being added while
- * the consumer driver is probing and pm_runtime_put_suppliers() will be called
- * subsequently.
- *
- * Note that this doesn't prevent rpm_put_suppliers() from decreasing the link's
- * rpm_active refcount down to one, so runtime suspend of the consumer end of
- * @link is not affected.
- */
-void pm_runtime_active_link(struct device_link *link, struct device *supplier)
-{
-	refcount_add(2, &link->rpm_active);
-	pm_runtime_get_noresume(supplier);
-}
-
 void pm_runtime_drop_link(struct device *dev)
 {
 	spin_lock_irq(&dev->power.lock);
diff --git a/include/linux/device.h b/include/linux/device.h
index b8fd2a1f859d..e9d1c768f972 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -854,6 +854,7 @@ struct device_link {
 #ifdef CONFIG_SRCU
 	struct rcu_head rcu_head;
 #endif
+	bool supplier_preactivated; /* Owned by consumer probe. */
 };
 
 /**
diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h
index bace7df51af4..f0fc4700b6ff 100644
--- a/include/linux/pm_runtime.h
+++ b/include/linux/pm_runtime.h
@@ -59,8 +59,6 @@ extern void pm_runtime_clean_up_links(struct device *dev);
 extern void pm_runtime_get_suppliers(struct device *dev);
 extern void pm_runtime_put_suppliers(struct device *dev);
 extern void pm_runtime_new_link(struct device *dev);
-extern void pm_runtime_active_link(struct device_link *link,
-				   struct device *supplier);
 extern void pm_runtime_drop_link(struct device *dev);
 
 static inline void pm_suspend_ignore_children(struct device *dev, bool enable)
@@ -178,8 +176,6 @@ static inline void pm_runtime_clean_up_links(struct device *dev) {}
 static inline void pm_runtime_get_suppliers(struct device *dev) {}
 static inline void pm_runtime_put_suppliers(struct device *dev) {}
 static inline void pm_runtime_new_link(struct device *dev) {}
-static inline void pm_runtime_active_link(struct device_link *link,
-					  struct device *supplier) {}
 static inline void pm_runtime_drop_link(struct device *dev) {}
 
 #endif /* !CONFIG_PM */
-- 
2.20.1

[PATCH AUTOSEL 4.19 220/671] ARM: 8847/1: pm: fix HYP/SVC mode mismatch when MCPM is used

[Sasha Levin]

From: Marek Szyprowski <m.szyprowski@samsung.com>

[ Upstream commit ca70ea43f80c98582f5ffbbd1e6f4da2742da0c4 ]

MCPM does a soft reset of the CPUs and uses common cpu_resume() routine to
perform low-level platform initialization. This results in a try to install
HYP stubs for the second time for each CPU and results in false HYP/SVC
mode mismatch detection. The HYP stubs are already installed at the
beginning of the kernel initialization on the boot CPU (head.S) or in the
secondary_startup() for other CPUs. To fix this issue MCPM code should use
a cpu_resume() routine without HYP stubs installation.

This change fixes HYP/SVC mode mismatch on Samsung Exynos5422-based Odroid
XU3/XU4/HC1 boards.

Fixes: 3721924c8154 ("ARM: 8081/1: MCPM: provide infrastructure to allow for MCPM loopback")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Anand Moon <linux.amoon@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/arm/common/mcpm_entry.c   |  2 +-
 arch/arm/include/asm/suspend.h |  1 +
 arch/arm/kernel/sleep.S        | 12 ++++++++++++
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/arch/arm/common/mcpm_entry.c b/arch/arm/common/mcpm_entry.c
index ad574d20415c..1b1b82b37ce0 100644
--- a/arch/arm/common/mcpm_entry.c
+++ b/arch/arm/common/mcpm_entry.c
@@ -381,7 +381,7 @@ static int __init nocache_trampoline(unsigned long _arg)
 	unsigned int cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
 	phys_reset_t phys_reset;
 
-	mcpm_set_entry_vector(cpu, cluster, cpu_resume);
+	mcpm_set_entry_vector(cpu, cluster, cpu_resume_no_hyp);
 	setup_mm_for_reboot();
 
 	__mcpm_cpu_going_down(cpu, cluster);
diff --git a/arch/arm/include/asm/suspend.h b/arch/arm/include/asm/suspend.h
index 452bbdcbcc83..506314265c6f 100644
--- a/arch/arm/include/asm/suspend.h
+++ b/arch/arm/include/asm/suspend.h
@@ -10,6 +10,7 @@ struct sleep_save_sp {
 };
 
 extern void cpu_resume(void);
+extern void cpu_resume_no_hyp(void);
 extern void cpu_resume_arm(void);
 extern int cpu_suspend(unsigned long, int (*)(unsigned long));
 
diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S
index a8257fc9cf2a..5dc8b80bb693 100644
--- a/arch/arm/kernel/sleep.S
+++ b/arch/arm/kernel/sleep.S
@@ -120,6 +120,14 @@ ENDPROC(cpu_resume_after_mmu)
 	.text
 	.align
 
+#ifdef CONFIG_MCPM
+	.arm
+THUMB(	.thumb			)
+ENTRY(cpu_resume_no_hyp)
+ARM_BE8(setend be)			@ ensure we are in BE mode
+	b	no_hyp
+#endif
+
 #ifdef CONFIG_MMU
 	.arm
 ENTRY(cpu_resume_arm)
@@ -135,6 +143,7 @@ ARM_BE8(setend be)			@ ensure we are in BE mode
 	bl	__hyp_stub_install_secondary
 #endif
 	safe_svcmode_maskall r1
+no_hyp:
 	mov	r1, #0
 	ALT_SMP(mrc p15, 0, r0, c0, c0, 5)
 	ALT_UP_B(1f)
@@ -163,6 +172,9 @@ ENDPROC(cpu_resume)
 
 #ifdef CONFIG_MMU
 ENDPROC(cpu_resume_arm)
+#endif
+#ifdef CONFIG_MCPM
+ENDPROC(cpu_resume_no_hyp)
 #endif
 
 	.align 2
-- 
2.20.1