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Commit 120924fb authored by Rama Aparna Mallavarapu's avatar Rama Aparna Mallavarapu
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coresight: tmc: Add IOMMU support to TMC ETR 



This adds IOMMU support to the TMC ETR driver. The IOMMU support helps
with contiguous VA usage for physically scattered memory and hence avoids
the need for native scatter gather mode usage in the TMC ETR driver.
It also helps with sandboxing TMC ETR and hence protecting the system from
erroneous TMC ETR accesses.

Change-Id: I17237bc02924e475c3fb324347734d01f72cc797
Signed-off-by: default avatarRama Aparna Mallavarapu <aparnam@codeaurora.org>
parent 66eef639

drivers/hwtracing/coresight/coresight-tmc.c

+59 −5
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 
#include <linux/of.h>

#include <linux/coresight.h>

#include <linux/amba/bus.h>

#include <asm/dma-iommu.h>



#include "coresight-priv.h"

#include "coresight-tmc.h"
@@ -457,6 +458,47 @@ static ssize_t block_size_store(struct device *dev, 
}

static DEVICE_ATTR_RW(block_size);



static int tmc_iommu_init(struct tmc_drvdata *drvdata)

{

	struct device_node *node = drvdata->dev->of_node;

	int atomic_ctx = 1, ret = 0;



	if (!of_property_read_bool(node, "iommus"))

		return 0;



	drvdata->iommu_mapping = arm_iommu_create_mapping(&amba_bustype,

							0, (SZ_1G * 4ULL));

	if (IS_ERR(drvdata->iommu_mapping)) {

		dev_err(drvdata->dev, "Create mapping failed, err = %d\n", ret);

		ret = PTR_ERR(drvdata->iommu_mapping);

		goto iommu_map_err;

	}



	ret = arm_iommu_attach_device(drvdata->dev, drvdata->iommu_mapping);

	if (ret) {

		dev_err(drvdata->dev, "Attach device failed, err = %d\n", ret);

		goto iommu_attach_fail;

	}



	return ret;



iommu_attach_fail:

	arm_iommu_release_mapping(drvdata->iommu_mapping);

iommu_map_err:

	return ret;

}



static void tmc_iommu_deinit(struct tmc_drvdata *drvdata)

{

	if (!drvdata->iommu_mapping)

		return;



	arm_iommu_detach_device(drvdata->dev);

	arm_iommu_release_mapping(drvdata->iommu_mapping);



	drvdata->iommu_mapping = NULL;

}



static struct attribute *coresight_tmc_etf_attrs[] = {

	&dev_attr_trigger_cntr.attr,

	NULL,
@@ -590,6 +632,12 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id) 


	pm_runtime_put(&adev->dev);



	ret = tmc_iommu_init(drvdata);

	if (ret) {

		dev_err(dev, "TMC SMMU init failed, err =%d\n", ret);

		goto out;

	}



	ctidata = of_get_coresight_cti_data(dev, adev->dev.of_node);

	if (IS_ERR(ctidata)) {

		dev_err(dev, "invalid cti data\n");
@@ -618,7 +666,7 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id) 
		desc.ops = &tmc_etr_cs_ops;

		ret = tmc_etr_setup_caps(drvdata, devid, id->data);

		if (ret)

			goto out;

			goto out_iommu_deinit;

		desc.groups = coresight_tmc_etr_groups;

		desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER;
@@ -626,7 +674,7 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id) 


		ret = tmc_etr_bam_init(adev, drvdata);

		if (ret)

			goto out;

			goto out_iommu_deinit;

		break;

	case TMC_CONFIG_TYPE_ETF:

		desc.type = CORESIGHT_DEV_TYPE_LINKSINK;
@@ -637,21 +685,27 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id) 
	default:

		pr_err("%s: Unsupported TMC config\n", pdata->name);

		ret = -EINVAL;

		goto out;

		goto out_iommu_deinit;

	}



	drvdata->csdev = coresight_register(&desc);

	if (IS_ERR(drvdata->csdev)) {

		ret = PTR_ERR(drvdata->csdev);

		goto out;

		goto out_iommu_deinit;

	}



	drvdata->miscdev.name = pdata->name;

	drvdata->miscdev.minor = MISC_DYNAMIC_MINOR;

	drvdata->miscdev.fops = &tmc_fops;

	ret = misc_register(&drvdata->miscdev);

	if (ret)

	if (ret) {

		tmc_iommu_deinit(drvdata);

		coresight_unregister(drvdata->csdev);

	}

	return ret;



out_iommu_deinit:

	tmc_iommu_deinit(drvdata);

out:

	return ret;

}

drivers/hwtracing/coresight/coresight-tmc.h

+1 −0
Original line number Diff line number Diff line
@@ -220,6 +220,7 @@ struct tmc_drvdata { 
	struct coresight_cti	*cti_flush;

	struct coresight_cti	*cti_reset;

	struct byte_cntr	*byte_cntr;

	struct dma_iommu_mapping *iommu_mapping;

};



/* Generic functions */