[PATCH v4 16/26] iommu/arm-smmu-v3: Add dev_to_master() helper

Jean-Philippe Brucker
2020-02-24T18:25:14Z

We'll need to frequently find the SMMU master associated to a device
when implementing SVA. Move it to a separate function.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
---
drivers/iommu/arm-smmu-v3.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 77a846440ba6..54bd6913d648 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -747,6 +747,15 @@ static struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom)
return container_of(dom, struct arm_smmu_domain, domain);
}

+static struct arm_smmu_master *dev_to_master(struct device *dev)
+{
+ struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+
+ if (!fwspec)
+ return NULL;
+ return fwspec->iommu_priv;
+}
+
static void parse_driver_options(struct arm_smmu_device *smmu)
{
int i = 0;
@@ -2940,15 +2949,13 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
{
int ret = 0;
unsigned long flags;
- struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
struct arm_smmu_device *smmu;
+ struct arm_smmu_master *master = dev_to_master(dev);
struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
- struct arm_smmu_master *master;

- if (!fwspec)
+ if (!master)
return -ENOENT;

- master = fwspec->iommu_priv;
smmu = master->smmu;

arm_smmu_detach_dev(master);
--
2.25.0