Re: [PATCH v3 08/10] iommu/arm-smmu-v3: Reserve any RMR regions associated with a dev

[Robin Murphy]

On 2021-04-20 09:27, Shameer Kolothum wrote:
Get RMR regions associated with a dev reserved so that there is
a unity mapping for them in SMMU.
Signed-off-by: Shameer Kolothum <shameerali.kolothum.th...@huawei.com>
---
  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 29 +++++++++++++++++++++
  1 file changed, 29 insertions(+)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c 
b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 14e9c7034c04..8bacedf7bb34 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2531,6 +2531,34 @@ static int arm_smmu_of_xlate(struct device *dev, struct 
of_phandle_args *args)
        return iommu_fwspec_add_ids(dev, args->args, 1);
  }
  
+static bool arm_smmu_dev_has_rmr(struct arm_smmu_master *master,
+                                struct iommu_rmr *e)
+{
+       int i;
+
+       for (i = 0; i < master->num_sids; i++) {
+               if (e->sid == master->sids[i])
+                       return true;
+       }
+
+       return false;
+}
+
+static void arm_smmu_rmr_get_resv_regions(struct device *dev,
+                                         struct list_head *head)
+{
+       struct arm_smmu_master *master = dev_iommu_priv_get(dev);
+       struct arm_smmu_device *smmu = master->smmu;
+       struct iommu_rmr *rmr;
+
+       list_for_each_entry(rmr, &smmu->rmr_list, list) {
+               if (!arm_smmu_dev_has_rmr(master, rmr))
+                       continue;
+
+               iommu_dma_get_rmr_resv_regions(dev, rmr, head);
+       }
+}
+

TBH I wouldn't have thought we need a driver-specific hook for this, or 
is it too painful to correlate fwspec->iommu_fwnode back to the relevant 
IORT node generically?

Robin.

  static void arm_smmu_get_resv_regions(struct device *dev,
                                      struct list_head *head)
  {
@@ -2545,6 +2573,7 @@ static void arm_smmu_get_resv_regions(struct device *dev,
        list_add_tail(&region->list, head);
  
  	iommu_dma_get_resv_regions(dev, head);
+       arm_smmu_rmr_get_resv_regions(dev, head);
  }
  
  static bool arm_smmu_dev_has_feature(struct device *dev,

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