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Commit f02d235b authored by Rama Aparna Mallavarapu's avatar Rama Aparna Mallavarapu Committed by Gerrit - the friendly Code Review server
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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>
Signed-off-by: default avatarMulu He <muluhe@codeaurora.org>
parent bfd4eeed

drivers/hwtracing/coresight/coresight-tmc.c

+56 −2
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
#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"
@@ -446,6 +447,47 @@ 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 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_OR_NULL(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,

	&dev_attr_buffer_size.attr,
@@ -653,18 +695,30 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id) 
		drvdata->byte_cntr = byte_cntr_init(adev, drvdata);

	}



	ret = tmc_iommu_init(drvdata);

	if (ret) {

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

		goto out;

	}



	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) {

		coresight_unregister(drvdata->csdev);

		goto out_iommu_deinit;

	}

	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
@@ -227,6 +227,7 @@ struct tmc_drvdata { 
	struct coresight_cti	*cti_reset;

	enum tmc_etr_out_mode	out_mode;

	struct byte_cntr	*byte_cntr;

	struct dma_iommu_mapping *iommu_mapping;

};



struct etr_buf_operations {