[PATCH v4 8/8] iommu/dma: Reserve any RMR regions associated with a dev

[Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx>]

Get ACPI IORT 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.thodi@xxxxxxxxxx>
---
 drivers/iommu/dma-iommu.c | 66 ++++++++++++++++++++++++++++++++++++---
 1 file changed, 61 insertions(+), 5 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 2d9caf548a32..6838caf3e8ff 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -174,22 +174,78 @@ void iommu_put_dma_cookie(struct iommu_domain *domain)
 }
 EXPORT_SYMBOL(iommu_put_dma_cookie);
 
+static bool iommu_dma_dev_has_rmr(struct iommu_fwspec *fwspec,
+				  struct iommu_rmr *e)
+{
+	int i;
+
+	for (i = 0; i < fwspec->num_ids; i++) {
+		if (e->sid == fwspec->ids[i])
+			return true;
+	}
+
+	return false;
+}
+
+static void iommu_dma_get_rmr_resv_regions(struct device *dev,
+					   struct list_head *list)
+{
+	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+	struct list_head rmr_list;
+	struct iommu_rmr *rmr;
+
+	INIT_LIST_HEAD(&rmr_list);
+	if (iommu_dma_get_rmrs(fwspec->iommu_fwnode, &rmr_list))
+		return;
+
+	if (dev_is_pci(dev)) {
+		struct pci_dev *pdev = to_pci_dev(dev);
+		struct pci_host_bridge *host = pci_find_host_bridge(pdev->bus);
+
+		if (!host->preserve_config)
+			return;
+	}
+
+	list_for_each_entry(rmr, &rmr_list, list) {
+		int prot = IOMMU_READ | IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO;
+		struct iommu_resv_region *region;
+		enum iommu_resv_type type;
+
+		if (!iommu_dma_dev_has_rmr(fwspec, rmr))
+			continue;
+
+		if (rmr->flags & IOMMU_RMR_REMAP_PERMITTED)
+			type = IOMMU_RESV_DIRECT_RELAXABLE;
+		else
+			type = IOMMU_RESV_DIRECT;
+
+		region = iommu_alloc_resv_region(rmr->base_address,
+						 rmr->length, prot,
+						 type);
+		if (!region)
+			return;
+
+		list_add_tail(&region->list, list);
+	}
+}
 /**
  * iommu_dma_get_resv_regions - Reserved region driver helper
  * @dev: Device from iommu_get_resv_regions()
  * @list: Reserved region list from iommu_get_resv_regions()
  *
  * IOMMU drivers can use this to implement their .get_resv_regions callback
- * for general non-IOMMU-specific reservations. Currently, this covers GICv3
- * ITS region reservation on ACPI based ARM platforms that may require HW MSI
- * reservation.
+ * for general non-IOMMU-specific reservations. Currently this covers,
+ *  -GICv3 ITS region reservation on ACPI based ARM platforms that may
+ *   require HW MSI reservation.
+ *  -Any ACPI IORT RMR memory range reservations (IORT spec rev E.b)
  */
 void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list)
 {
 
-	if (!is_of_node(dev_iommu_fwspec_get(dev)->iommu_fwnode))
+	if (!is_of_node(dev_iommu_fwspec_get(dev)->iommu_fwnode)) {
 		iort_iommu_msi_get_resv_regions(dev, list);
-
+		iommu_dma_get_rmr_resv_regions(dev, list);
+	}
 }
 EXPORT_SYMBOL(iommu_dma_get_resv_regions);
 
-- 
2.17.1