Commit b67483b3 authored by Robin Murphy's avatar Robin Murphy Committed by Joerg Roedel
Browse files

iommu/dma: Centralise iommu_setup_dma_ops() 



It's somewhat hard to see, but arm64's arch_setup_dma_ops() should only
ever call iommu_setup_dma_ops() after a successful iommu_probe_device(),
which means there should be no harm in achieving the same order of
operations by running it off the back of iommu_probe_device() itself.
This then puts it in line with the x86 and s390 .probe_finalize bodges,
letting us pull it all into the main flow properly. As a bonus this lets
us fold in and de-scope the PCI workaround setup as well.

At this point we can also then pull the call up inside the group mutex,
and avoid having to think about whether iommu_group_store_type() could
theoretically race and free the domain if iommu_setup_dma_ops() ran just
*before* iommu_device_use_default_domain() claims it... Furthermore we
replace one .probe_finalize call completely, since the only remaining
implementations are now one which only needs to run once for the initial
boot-time probe, and two which themselves render that path unreachable.

This leaves us a big step closer to realistically being able to unpick
the variety of different things that iommu_setup_dma_ops() has been
muddling together, and further streamline iommu-dma into core API flows
in future.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> # For Intel IOMMU
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Tested-by: default avatarHanjun Guo <guohanjun@huawei.com>
Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/bebea331c1d688b34d9862eefd5ede47503961b8.1713523152.git.robin.murphy@arm.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent ad4750b0

arch/arm64/mm/dma-mapping.c

+0 −2
Original line number Diff line number Diff line
@@ -58,8 +58,6 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, 
		   ARCH_DMA_MINALIGN, cls);



	dev->dma_coherent = coherent;

	if (device_iommu_mapped(dev))

		iommu_setup_dma_ops(dev, dma_base, dma_base + size - 1);



	xen_setup_dma_ops(dev);

}

drivers/iommu/amd/iommu.c

+0 −8
Original line number Diff line number Diff line
@@ -2175,13 +2175,6 @@ static struct iommu_device *amd_iommu_probe_device(struct device *dev) 
	return iommu_dev;

}



static void amd_iommu_probe_finalize(struct device *dev)

{

	/* Domains are initialized for this device - have a look what we ended up with */

	set_dma_ops(dev, NULL);

	iommu_setup_dma_ops(dev, 0, U64_MAX);

}



static void amd_iommu_release_device(struct device *dev)

{

	struct amd_iommu *iommu;
@@ -2784,7 +2777,6 @@ const struct iommu_ops amd_iommu_ops = { 
	.domain_alloc_user = amd_iommu_domain_alloc_user,

	.probe_device = amd_iommu_probe_device,

	.release_device = amd_iommu_release_device,

	.probe_finalize = amd_iommu_probe_finalize,

	.device_group = amd_iommu_device_group,

	.get_resv_regions = amd_iommu_get_resv_regions,

	.is_attach_deferred = amd_iommu_is_attach_deferred,

drivers/iommu/dma-iommu.c

+6 −12
Original line number Diff line number Diff line
@@ -1741,25 +1741,20 @@ static const struct dma_map_ops iommu_dma_ops = { 
	.max_mapping_size       = iommu_dma_max_mapping_size,

};



/*

 * The IOMMU core code allocates the default DMA domain, which the underlying

 * IOMMU driver needs to support via the dma-iommu layer.

 */

void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 dma_limit)

void iommu_setup_dma_ops(struct device *dev)

{

	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);



	if (!domain)

		goto out_err;

	if (dev_is_pci(dev))

		dev->iommu->pci_32bit_workaround = !iommu_dma_forcedac;



	/*

	 * The IOMMU core code allocates the default DMA domain, which the

	 * underlying IOMMU driver needs to support via the dma-iommu layer.

	 */

	if (iommu_is_dma_domain(domain)) {

		if (iommu_dma_init_domain(domain, dev))

			goto out_err;

		dev->dma_ops = &iommu_dma_ops;

	} else if (dev->dma_ops == &iommu_dma_ops) {

		/* Clean up if we've switched *from* a DMA domain */

		dev->dma_ops = NULL;

	}



	return;
@@ -1767,7 +1762,6 @@ void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 dma_limit) 
	 pr_warn("Failed to set up IOMMU for device %s; retaining platform DMA ops\n",

		 dev_name(dev));

}

EXPORT_SYMBOL_GPL(iommu_setup_dma_ops);



static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev,

		phys_addr_t msi_addr, struct iommu_domain *domain)

drivers/iommu/dma-iommu.h

+6 −8
Original line number Diff line number Diff line
@@ -9,6 +9,8 @@ 


#ifdef CONFIG_IOMMU_DMA



void iommu_setup_dma_ops(struct device *dev);



int iommu_get_dma_cookie(struct iommu_domain *domain);

void iommu_put_dma_cookie(struct iommu_domain *domain);
@@ -17,13 +19,13 @@ int iommu_dma_init_fq(struct iommu_domain *domain); 
void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list);



extern bool iommu_dma_forcedac;

static inline void iommu_dma_set_pci_32bit_workaround(struct device *dev)

{

	dev->iommu->pci_32bit_workaround = !iommu_dma_forcedac;

}



#else /* CONFIG_IOMMU_DMA */



static inline void iommu_setup_dma_ops(struct device *dev)

{

}



static inline int iommu_dma_init_fq(struct iommu_domain *domain)

{

	return -EINVAL;
@@ -42,9 +44,5 @@ static inline void iommu_dma_get_resv_regions(struct device *dev, struct list_he 
{

}



static inline void iommu_dma_set_pci_32bit_workaround(struct device *dev)

{

}



#endif	/* CONFIG_IOMMU_DMA */

#endif	/* __DMA_IOMMU_H */

drivers/iommu/intel/iommu.c

+0 −7
Original line number Diff line number Diff line
@@ -4349,12 +4349,6 @@ static void intel_iommu_release_device(struct device *dev) 
	set_dma_ops(dev, NULL);

}



static void intel_iommu_probe_finalize(struct device *dev)

{

	set_dma_ops(dev, NULL);

	iommu_setup_dma_ops(dev, 0, U64_MAX);

}



static void intel_iommu_get_resv_regions(struct device *device,

					 struct list_head *head)

{
@@ -4834,7 +4828,6 @@ const struct iommu_ops intel_iommu_ops = { 
	.domain_alloc		= intel_iommu_domain_alloc,

	.domain_alloc_user	= intel_iommu_domain_alloc_user,

	.probe_device		= intel_iommu_probe_device,

	.probe_finalize		= intel_iommu_probe_finalize,

	.release_device		= intel_iommu_release_device,

	.get_resv_regions	= intel_iommu_get_resv_regions,

	.device_group		= intel_iommu_device_group,