[PATCH AUTOSEL 4.19 07/34] PM / devfreq: Fix devfreq_notifier_call returning errno

[PATCH AUTOSEL 4.19 07/34] PM / devfreq: Fix devfreq_notifier_call returning errno

[Sasha Levin]

From: Leonard Crestez <leonard.crestez@nxp.com>

[ Upstream commit e876e710ede23f670494331e062d643928e4142a ]

Notifier callbacks shouldn't return negative errno but one of the
NOTIFY_OK/DONE/BAD values.

The OPP core will ignore return values from notifiers but returning a
value that matches NOTIFY_STOP_MASK will stop the notification chain.

Fix by always returning NOTIFY_OK.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/devfreq/devfreq.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 61fbaa89d7b4f..34e297f28fc2a 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -538,26 +538,28 @@ static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type,
 				 void *devp)
 {
 	struct devfreq *devfreq = container_of(nb, struct devfreq, nb);
-	int ret;
+	int err = -EINVAL;
 
 	mutex_lock(&devfreq->lock);
 
 	devfreq->scaling_min_freq = find_available_min_freq(devfreq);
-	if (!devfreq->scaling_min_freq) {
-		mutex_unlock(&devfreq->lock);
-		return -EINVAL;
-	}
+	if (!devfreq->scaling_min_freq)
+		goto out;
 
 	devfreq->scaling_max_freq = find_available_max_freq(devfreq);
-	if (!devfreq->scaling_max_freq) {
-		mutex_unlock(&devfreq->lock);
-		return -EINVAL;
-	}
+	if (!devfreq->scaling_max_freq)
+		goto out;
+
+	err = update_devfreq(devfreq);
 
-	ret = update_devfreq(devfreq);
+out:
 	mutex_unlock(&devfreq->lock);
+	if (err)
+		dev_err(devfreq->dev.parent,
+			"failed to update frequency from OPP notifier (%d)\n",
+			err);
 
-	return ret;
+	return NOTIFY_OK;
 }
 
 /**
-- 
2.20.1

[PATCH AUTOSEL 4.19 08/34] PM / devfreq: Set scaling_max_freq to max on OPP notifier error

[Sasha Levin]

From: Leonard Crestez <leonard.crestez@nxp.com>

[ Upstream commit e7cc792d00049c874010b398a27c3cc7bc8fef34 ]

The devfreq_notifier_call functions will update scaling_min_freq and
scaling_max_freq when the OPP table is updated.

If fetching the maximum frequency fails then scaling_max_freq remains
set to zero which is confusing. Set to ULONG_MAX instead so we don't
need special handling for this case in other places.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/devfreq/devfreq.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 34e297f28fc2a..a47e76a62287f 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -547,8 +547,10 @@ static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type,
 		goto out;
 
 	devfreq->scaling_max_freq = find_available_max_freq(devfreq);
-	if (!devfreq->scaling_max_freq)
+	if (!devfreq->scaling_max_freq) {
+		devfreq->scaling_max_freq = ULONG_MAX;
 		goto out;
+	}
 
 	err = update_devfreq(devfreq);
 
-- 
2.20.1

[PATCH AUTOSEL 4.19 09/34] PM / devfreq: Don't fail devfreq_dev_release if not in list

[Sasha Levin]

From: Leonard Crestez <leonard.crestez@nxp.com>

[ Upstream commit 42a6b25e67df6ee6675e8d1eaf18065bd73328ba ]

Right now devfreq_dev_release will print a warning and abort the rest of
the cleanup if the devfreq instance is not part of the global
devfreq_list. But this is a valid scenario, for example it can happen if
the governor can't be found or on any other init error that happens
after device_register.

Initialize devfreq->node to an empty list head in devfreq_add_device so
that list_del becomes a safe noop inside devfreq_dev_release and we can
continue the rest of the cleanup.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/devfreq/devfreq.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index a47e76a62287f..69bbb1e9ab23d 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -575,11 +575,6 @@ static void devfreq_dev_release(struct device *dev)
 	struct devfreq *devfreq = to_devfreq(dev);
 
 	mutex_lock(&devfreq_list_lock);
-	if (IS_ERR(find_device_devfreq(devfreq->dev.parent))) {
-		mutex_unlock(&devfreq_list_lock);
-		dev_warn(&devfreq->dev, "releasing devfreq which doesn't exist\n");
-		return;
-	}
 	list_del(&devfreq->node);
 	mutex_unlock(&devfreq_list_lock);
 
@@ -634,6 +629,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
 	devfreq->dev.parent = dev;
 	devfreq->dev.class = devfreq_class;
 	devfreq->dev.release = devfreq_dev_release;
+	INIT_LIST_HEAD(&devfreq->node);
 	devfreq->profile = profile;
 	strncpy(devfreq->governor_name, governor_name, DEVFREQ_NAME_LEN);
 	devfreq->previous_freq = profile->initial_freq;
-- 
2.20.1

[PATCH AUTOSEL 4.19 34/34] PM / hibernate: memory_bm_find_bit(): Tighten node optimisation

[Sasha Levin]

From: Andy Whitcroft <apw@canonical.com>

[ Upstream commit da6043fe85eb5ec621e34a92540735dcebbea134 ]

When looking for a bit by number we make use of the cached result from the
preceding lookup to speed up operation.  Firstly we check if the requested
pfn is within the cached zone and if not lookup the new zone.  We then
check if the offset for that pfn falls within the existing cached node.
This happens regardless of whether the node is within the zone we are
now scanning.  With certain memory layouts it is possible for this to
false trigger creating a temporary alias for the pfn to a different bit.
This leads the hibernation code to free memory which it was never allocated
with the expected fallout.

Ensure the zone we are scanning matches the cached zone before considering
the cached node.

Deep thanks go to Andrea for many, many, many hours of hacking and testing
that went into cornering this bug.

Reported-by: Andrea Righi <andrea.righi@canonical.com>
Tested-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 kernel/power/snapshot.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 3d37c279c0900..f2635fc751d93 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -736,8 +736,15 @@ static int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
 	 * We have found the zone. Now walk the radix tree to find the leaf node
 	 * for our PFN.
 	 */
+
+	/*
+	 * If the zone we wish to scan is the the current zone and the
+	 * pfn falls into the current node then we do not need to walk
+	 * the tree.
+	 */
 	node = bm->cur.node;
-	if (((pfn - zone->start_pfn) & ~BM_BLOCK_MASK) == bm->cur.node_pfn)
+	if (zone == bm->cur.zone &&
+	    ((pfn - zone->start_pfn) & ~BM_BLOCK_MASK) == bm->cur.node_pfn)
 		goto node_found;
 
 	node      = zone->rtree;
-- 
2.20.1