Commit 803b5277 authored by Omar Ramirez Luna's avatar Omar Ramirez Luna Committed by Joerg Roedel
Browse files

iommu: OMAP: device detach on domain destroy 



'domain_destroy with devices attached' case isn't yet handled, instead
code assumes that the device was already detached.

If the domain is destroyed the hardware still has access to invalid
pointers to its page table and internal iommu object. In order to
detach the users we need to track devices using the iommu, current
use cases only have one user of iommu per instance. When required
this can evolve to a list with the devices using the iommu_dev.

Reported-by: default avatarJoerg Roedel <joro@8bytes.org>
Reviewed-by: default avatarOhad Ben-Cohen <ohad@wizery.com>
Signed-off-by: default avatarOmar Ramirez Luna <omar.luna@linaro.org>
Signed-off-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
parent 00341028

drivers/iommu/omap-iommu.c

+23 −9
Original line number Diff line number Diff line
@@ -41,11 +41,13 @@ 
 * @pgtable:	the page table

 * @iommu_dev:	an omap iommu device attached to this domain. only a single

 *		iommu device can be attached for now.

 * @dev:	Device using this domain.

 * @lock:	domain lock, should be taken when attaching/detaching

 */

struct omap_iommu_domain {

	u32 *pgtable;

	struct omap_iommu *iommu_dev;

	struct device *dev;

	spinlock_t lock;

};
@@ -1081,6 +1083,7 @@ omap_iommu_attach_dev(struct iommu_domain *domain, struct device *dev) 
	}



	omap_domain->iommu_dev = arch_data->iommu_dev = oiommu;

	omap_domain->dev = dev;

	oiommu->domain = domain;



out:
@@ -1088,19 +1091,16 @@ out: 
	return ret;

}



static void omap_iommu_detach_dev(struct iommu_domain *domain,

static void _omap_iommu_detach_dev(struct omap_iommu_domain *omap_domain,

			struct device *dev)

{

	struct omap_iommu_domain *omap_domain = domain->priv;

	struct omap_iommu_arch_data *arch_data = dev->archdata.iommu;

	struct omap_iommu *oiommu = dev_to_omap_iommu(dev);



	spin_lock(&omap_domain->lock);

	struct omap_iommu_arch_data *arch_data = dev->archdata.iommu;



	/* only a single device is supported per domain for now */

	if (omap_domain->iommu_dev != oiommu) {

		dev_err(dev, "invalid iommu device\n");

		goto out;

		return;

	}



	iopgtable_clear_entry_all(oiommu);
@@ -1108,8 +1108,16 @@ static void omap_iommu_detach_dev(struct iommu_domain *domain, 
	omap_iommu_detach(oiommu);



	omap_domain->iommu_dev = arch_data->iommu_dev = NULL;

	omap_domain->dev = NULL;

}



out:

static void omap_iommu_detach_dev(struct iommu_domain *domain,

				 struct device *dev)

{

	struct omap_iommu_domain *omap_domain = domain->priv;



	spin_lock(&omap_domain->lock);

	_omap_iommu_detach_dev(omap_domain, dev);

	spin_unlock(&omap_domain->lock);

}
@@ -1148,13 +1156,19 @@ out: 
	return -ENOMEM;

}



/* assume device was already detached */

static void omap_iommu_domain_destroy(struct iommu_domain *domain)

{

	struct omap_iommu_domain *omap_domain = domain->priv;



	domain->priv = NULL;



	/*

	 * An iommu device is still attached

	 * (currently, only one device can be attached) ?

	 */

	if (omap_domain->iommu_dev)

		_omap_iommu_detach_dev(omap_domain, omap_domain->dev);



	kfree(omap_domain->pgtable);

	kfree(omap_domain);

}

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