[PATCH 2/2] iommu/msm: Use identity domain for GPU and display

[Rob Clark <robin.clark@oss.qualcomm.com>]

Similar to commit 0e764a01015d ("iommu/arm-smmu: Allow client devices to
select direct mapping") for arm-smmu-qcom, match GPU and display compat
strings to pick identity domain time.

The drm/msm driver attaches it's own domain, which it manages directly,
so we don't want an iommu managed domain interfering.

Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
---
 drivers/iommu/msm_iommu.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/iommu/msm_iommu.c b/drivers/iommu/msm_iommu.c
index 4ef1e8c8244b..1c5011432628 100644
--- a/drivers/iommu/msm_iommu.c
+++ b/drivers/iommu/msm_iommu.c
@@ -12,6 +12,7 @@
 #include <linux/io.h>
 #include <linux/io-pgtable.h>
 #include <linux/interrupt.h>
+#include <linux/of_device.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>
 #include <linux/slab.h>
@@ -691,12 +692,27 @@ irqreturn_t msm_iommu_fault_handler(int irq, void *dev_id)
 	return 0;
 }
 
+static const struct of_device_id msm_iommu_client_of_match[] = {
+	{ .compatible = "qcom,adreno" },
+	{ .compatible = "qcom,mdp4" },
+	{ }
+};
+
+static int msm_iommu_def_domain_type(struct device *dev)
+{
+	const struct of_device_id *match =
+		of_match_device(msm_iommu_client_of_match, dev);
+
+	return match ? IOMMU_DOMAIN_IDENTITY : 0;
+}
+
 static struct iommu_ops msm_iommu_ops = {
 	.identity_domain = &msm_iommu_identity_domain,
 	.domain_alloc_paging = msm_iommu_domain_alloc_paging,
 	.probe_device = msm_iommu_probe_device,
 	.device_group = generic_device_group,
 	.of_xlate = qcom_iommu_of_xlate,
+	.def_domain_type = msm_iommu_def_domain_type,
 	.default_domain_ops = &(const struct iommu_domain_ops) {
 		.attach_dev	= msm_iommu_attach_dev,
 		.map_pages	= msm_iommu_map,
-- 
2.56.0