Re: [PATCHv2 3/6] iommu/arm-smmu: Implement iommu_ops->def_domain_type call-back

From: Sai Prakash Ranjan
Date: Mon Apr 20 2020 - 12:27:57 EST


Hi Robin,

On 2020-04-20 20:56, Robin Murphy wrote:
On 2020-04-20 3:37 pm, Sai Prakash Ranjan wrote:
Implement the new def_domain_type call-back for the ARM
SMMU driver. We need this to support requesting the domain
type by the client devices.

Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@xxxxxxxxxxxxxx>
---
drivers/iommu/arm-smmu.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index e622f4e33379..b5d1d52dfbb8 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -1609,6 +1609,25 @@ static void arm_smmu_get_resv_regions(struct device *dev,
iommu_dma_get_resv_regions(dev, head);
}
+static int arm_smmu_def_domain_type(struct device *dev)
+{
+ struct iommu_fwspec *fwspec;
+ struct arm_smmu_device *smmu;
+
+ fwspec = dev_iommu_fwspec_get(dev);
+ if (!fwspec || fwspec->ops != &arm_smmu_ops)
+ return -ENODEV;
+
+ smmu = arm_smmu_get_by_fwnode(fwspec->iommu_fwnode);
+ if (!smmu)
+ return -ENODEV;
+

AFAICS this should only ever be called for a device in a group, which
means an initial ->probe_device has succeeded and rather than
defensively going the long way round, we can safely assume this:

struct arm_smmu_master_cfg = dev_iommu_priv_get(dev);
struct arm_smmu_impl *impl = cfg->smmu->impl;

if (impl && impl->req_domain)
return impl->req_domain(dev);


Yes you are right, will use this.

Thanks,
Sai
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