[RFC 5/5] iommu/arm-smmu: Allow direct mapping for MSI region

[Jitendra Bhivare via iommu]

Current ARM SMMU virtualizes MSI addresses to IOVA space.

In iProc SoCs, MSI needs to be steered. Allow reserving MSI address range
using DT node entry as direct region.

Signed-off-by: Jitendra Bhivare <jitendra.bhiv...@broadcom.com>
---
 drivers/iommu/arm-smmu.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 78d4c6b..7b34980 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -1533,8 +1533,11 @@ static int arm_smmu_of_xlate(struct device *dev, struct 
of_phandle_args *args)
 static void arm_smmu_get_resv_regions(struct device *dev,
                                      struct list_head *head)
 {
+       struct iommu_fwspec *fwspec = dev->iommu_fwspec;
+       struct arm_smmu_device *smmu = fwspec_smmu(fwspec);
        struct iommu_resv_region *region;
-       int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO;
+       struct of_iommu_resv_region of_region;
+       int index = 0, prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO;
 
        region = iommu_alloc_resv_region(MSI_IOVA_BASE, MSI_IOVA_LENGTH,
                                         prot, IOMMU_RESV_SW_MSI);
@@ -1543,6 +1546,15 @@ static void arm_smmu_get_resv_regions(struct device *dev,
 
        list_add_tail(&region->list, head);
 
+       if (!of_get_resv_region(smmu->dev->of_node, "msi", &index,
+                               &of_region)) {
+               region = iommu_alloc_resv_region(of_region.bus_addr,
+                                                of_region.size,
+                                                of_region.prot,
+                                                IOMMU_RESV_DIRECT);
+               if (region)
+                       list_add_tail(&region->list, head);
+       }
        iommu_dma_get_resv_regions(dev, head);
 }
 
-- 
2.7.4

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu