Hi Robin,
On 2020-04-16 19:28, Robin Murphy wrote:
On 2020-01-22 11:48 am, Sai Prakash Ranjan wrote:
From: Jordan Crouse <jcrouse@xxxxxxxxxxxxxx>
Some client devices want to directly map the IOMMU themselves instead
of using the DMA domain. Allow those devices to opt in to direct
mapping by way of a list of compatible strings.
Signed-off-by: Jordan Crouse <jcrouse@xxxxxxxxxxxxxx>
Co-developed-by: Sai Prakash Ranjan <saiprakash.ranjan@xxxxxxxxxxxxxx>
Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@xxxxxxxxxxxxxx>
---
drivers/iommu/arm-smmu-qcom.c | 39
+++++++++++++++++++++++++++++++++++
drivers/iommu/arm-smmu.c | 3 +++
drivers/iommu/arm-smmu.h | 5 +++++
3 files changed, 47 insertions(+)
diff --git a/drivers/iommu/arm-smmu-qcom.c
b/drivers/iommu/arm-smmu-qcom.c
index 64a4ab270ab7..ff746acd1c81 100644
--- a/drivers/iommu/arm-smmu-qcom.c
+++ b/drivers/iommu/arm-smmu-qcom.c
@@ -3,6 +3,7 @@
* Copyright (c) 2019, The Linux Foundation. All rights reserved.
*/
+#include <linux/of_device.h>
#include <linux/qcom_scm.h>
#include "arm-smmu.h"
@@ -11,6 +12,43 @@ struct qcom_smmu {
struct arm_smmu_device smmu;
};
+static const struct arm_smmu_client_match_data qcom_adreno = {
+ .direct_mapping = true,
+};
+
+static const struct arm_smmu_client_match_data qcom_mdss = {
+ .direct_mapping = true,
+};
Might it make sense to group these by the desired SMMU behaviour
rather than (apparently) what kind of device the client happens to be,
which seems like a completely arbitrary distinction from the SMMU
driver's PoV?
Sorry, I did not get the "grouping by the desired SMMU behaviour" thing.
Could you please give some more details?
+
+static const struct of_device_id qcom_smmu_client_of_match[] = {
+ { .compatible = "qcom,adreno", .data = &qcom_adreno },
+ { .compatible = "qcom,mdp4", .data = &qcom_mdss },
+ { .compatible = "qcom,mdss", .data = &qcom_mdss },
+ { .compatible = "qcom,sc7180-mdss", .data = &qcom_mdss },
+ { .compatible = "qcom,sdm845-mdss", .data = &qcom_mdss },
+ {},
+};
+
+static const struct arm_smmu_client_match_data *
+qcom_smmu_client_data(struct device *dev)
+{
+ const struct of_device_id *match =
+ of_match_device(qcom_smmu_client_of_match, dev);
+
+ return match ? match->data : NULL;
of_device_get_match_data() is your friend.
Ok will use it.
+}
+
+static int qcom_smmu_request_domain(struct device *dev)
+{
+ const struct arm_smmu_client_match_data *client;
+
+ client = qcom_smmu_client_data(dev);
+ if (client)
+ iommu_request_dm_for_dev(dev);
+
+ return 0;
+}
+
static int qcom_sdm845_smmu500_reset(struct arm_smmu_device *smmu)
{
int ret;
@@ -41,6 +79,7 @@ static int qcom_smmu500_reset(struct arm_smmu_device
*smmu)
}
static const struct arm_smmu_impl qcom_smmu_impl = {
+ .req_domain = qcom_smmu_request_domain,
.reset = qcom_smmu500_reset,
};
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 16c4b87af42b..67dd9326247a 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -1448,6 +1448,9 @@ static int arm_smmu_add_device(struct device
*dev)
device_link_add(dev, smmu->dev,
DL_FLAG_PM_RUNTIME | DL_FLAG_AUTOREMOVE_SUPPLIER);
+ if (smmu->impl && smmu->impl->req_domain)
+ return smmu->impl->req_domain(dev);
+
There are about 5 different patchsets flying around at the moment that
all touch default domain allocation, so this is a fast-moving target,
but I think where the dust should settle is with arm_smmu_ops
forwarding .def_domain_type (or whatever it ends up as) calls to
arm_smmu_impl as appropriate.
I'll wait till the dust settles down and then post the next version.
return 0;
out_cfg_free:
diff --git a/drivers/iommu/arm-smmu.h b/drivers/iommu/arm-smmu.h
index 8d1cd54d82a6..059dc9c39f64 100644
--- a/drivers/iommu/arm-smmu.h
+++ b/drivers/iommu/arm-smmu.h
@@ -244,6 +244,10 @@ enum arm_smmu_arch_version {
ARM_SMMU_V2,
};
+struct arm_smmu_client_match_data {
+ bool direct_mapping;
+};
Does this need to be public? I don't see the other users...
Will move this out.
Thanks,
Sai
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