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Commit 921b1f52 authored by Robin Murphy's avatar Robin Murphy Committed by Will Deacon
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arm64/dma-mapping: Remove default domain workaround 



With the IOMMU core now taking care of default domains for groups
regardless of bus type, we can gleefully rip out this stop-gap, as
slight recompense for having to expand the other one.

Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 226d89cb

arch/arm64/mm/dma-mapping.c

+8 −44
Original line number Diff line number Diff line
@@ -804,57 +804,24 @@ struct iommu_dma_notifier_data { 
static LIST_HEAD(iommu_dma_masters);

static DEFINE_MUTEX(iommu_dma_notifier_lock);



/*

 * Temporarily "borrow" a domain feature flag to to tell if we had to resort

 * to creating our own domain here, in case we need to clean it up again.

 */

#define __IOMMU_DOMAIN_FAKE_DEFAULT		(1U << 31)



static bool do_iommu_attach(struct device *dev, const struct iommu_ops *ops,

			   u64 dma_base, u64 size)

{

	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);



	/*

	 * Best case: The device is either part of a group which was

	 * already attached to a domain in a previous call, or it's

	 * been put in a default DMA domain by the IOMMU core.

	 */

	if (!domain) {

		/*

		 * Urgh. The IOMMU core isn't going to do default domains

		 * for non-PCI devices anyway, until it has some means of

		 * abstracting the entirely implementation-specific

		 * sideband data/SoC topology/unicorn dust that may or

		 * may not differentiate upstream masters.

		 * So until then, HORRIBLE HACKS!

	 * If the IOMMU driver has the DMA domain support that we require,

	 * then the IOMMU core will have already configured a group for this

	 * device, and allocated the default domain for that group.

	 */

		domain = ops->domain_alloc(IOMMU_DOMAIN_DMA);

		if (!domain)

			goto out_no_domain;



		domain->ops = ops;

		domain->type = IOMMU_DOMAIN_DMA | __IOMMU_DOMAIN_FAKE_DEFAULT;



		if (iommu_attach_device(domain, dev))

			goto out_put_domain;

	if (!domain || iommu_dma_init_domain(domain, dma_base, size)) {

		pr_warn("Failed to set up IOMMU for device %s; retaining platform DMA ops\n",

			dev_name(dev));

		return false;

	}



	if (iommu_dma_init_domain(domain, dma_base, size))

		goto out_detach;



	dev->archdata.dma_ops = &iommu_dma_ops;

	return true;



out_detach:

	iommu_detach_device(domain, dev);

out_put_domain:

	if (domain->type & __IOMMU_DOMAIN_FAKE_DEFAULT)

		iommu_domain_free(domain);

out_no_domain:

	pr_warn("Failed to set up IOMMU for device %s; retaining platform DMA ops\n",

		dev_name(dev));

	return false;

}



static void queue_iommu_attach(struct device *dev, const struct iommu_ops *ops,
@@ -971,11 +938,8 @@ void arch_teardown_dma_ops(struct device *dev) 
{

	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);



	if (domain) {

	if (WARN_ON(domain))

		iommu_detach_device(domain, dev);

		if (domain->type & __IOMMU_DOMAIN_FAKE_DEFAULT)

			iommu_domain_free(domain);

	}



	dev->archdata.dma_ops = NULL;

}