[PATCH v2 3/8] iommu: Add lockdep annotations for group list iterators

Robin Murphy
2023-01-26T18:26:41Z

Before we add any more common helpers for iterating or otherwise
accessing the group device list, let's start the good habit of
annotating their locking expectations for robustness.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---

v2: New. Note that I've left the group_pasid helpers, since they're
pretty much right next to where the relevant locking happens, and
highly unlikely to be reused from anywhere else anyway.

drivers/iommu/iommu.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index d48e5499e0fa..77f076030995 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -20,6 +20,7 @@
#include <linux/iommu.h>
#include <linux/idr.h>
#include <linux/err.h>
+#include <linux/lockdep.h>
#include <linux/pci.h>
#include <linux/pci-ats.h>
#include <linux/bitops.h>
@@ -1100,6 +1101,7 @@ static int iommu_group_device_count(struct iommu_group *group)
struct group_device *entry;
int ret = 0;

+ lockdep_assert_held(&group->mutex);
list_for_each_entry(entry, &group->devices, list)
ret++;

@@ -1112,6 +1114,7 @@ static int __iommu_group_for_each_dev(struct iommu_group *group, void *data,
struct group_device *device;
int ret = 0;

+ lockdep_assert_held(&group->mutex);
list_for_each_entry(device, &group->devices, list) {
ret = fn(device->dev, data);
if (ret)
--
2.36.1.dirty