[PATCH v12 07/17] iommu: Try to allocate blocking domain when probing device

Lu Baolu
2022-08-26T12:18:17Z

Allocate the blocking domain when probing devices if the driver supports
blocking domain allocation. Otherwise, revert to the previous behavior,
that is, use UNMANAGED domain instead when the blocking domain is needed.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Tested-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Tested-by: Tony Zhu <tony.zhu@intel.com>
---
drivers/iommu/iommu.c | 29 +++++++++++++++++------------
1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 2c9488d966ab..e985f4d5895f 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -318,6 +318,10 @@ int iommu_probe_device(struct device *dev)
mutex_lock(&group->mutex);
iommu_alloc_default_domain(group, dev);

+ /* Try to allocate a blocking domain */
+ group->blocking_domain = __iommu_domain_alloc(dev->bus,
+ IOMMU_DOMAIN_BLOCKED);
+
/*
* If device joined an existing group which has been claimed, don't
* attach the default domain.
@@ -1778,6 +1782,10 @@ int bus_iommu_probe(struct bus_type *bus)
/* Try to allocate default domain */
probe_alloc_default_domain(bus, group);

+ /* Try to allocate blocking domain */
+ group->blocking_domain =
+ __iommu_domain_alloc(bus, IOMMU_DOMAIN_BLOCKED);
+
if (!group->default_domain) {
mutex_unlock(&group->mutex);
continue;
@@ -3165,18 +3173,15 @@ static int __iommu_group_alloc_blocking_domain(struct iommu_group *group)
if (group->blocking_domain)
return 0;

- group->blocking_domain =
- __iommu_domain_alloc(dev->dev->bus, IOMMU_DOMAIN_BLOCKED);
- if (!group->blocking_domain) {
- /*
- * For drivers that do not yet understand IOMMU_DOMAIN_BLOCKED
- * create an empty domain instead.
- */
- group->blocking_domain = __iommu_domain_alloc(
- dev->dev->bus, IOMMU_DOMAIN_UNMANAGED);
- if (!group->blocking_domain)
- return -EINVAL;
- }
+ /*
+ * For drivers that do not yet understand IOMMU_DOMAIN_BLOCKED
+ * create an empty domain instead.
+ */
+ group->blocking_domain = __iommu_domain_alloc(dev->dev->bus,
+ IOMMU_DOMAIN_UNMANAGED);
+ if (!group->blocking_domain)
+ return -EINVAL;
+
return 0;
}

--
2.25.1