Commit ac6d7046 authored by Jean-Philippe Brucker's avatar Jean-Philippe Brucker Committed by Joerg Roedel
Browse files

iommu/dma: Pass address limit rather than size to iommu_setup_dma_ops() 



Passing a 64-bit address width to iommu_setup_dma_ops() is valid on
virtual platforms, but isn't currently possible. The overflow check in
iommu_dma_init_domain() prevents this even when @dma_base isn't 0. Pass
a limit address instead of a size, so callers don't have to fake a size
to work around the check.

The base and limit parameters are being phased out, because:
* they are redundant for x86 callers. dma-iommu already reserves the
  first page, and the upper limit is already in domain->geometry.
* they can now be obtained from dev->dma_range_map on Arm.
But removing them on Arm isn't completely straightforward so is left for
future work. As an intermediate step, simplify the x86 callers by
passing dummy limits.

Signed-off-by: default avatarJean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: default avatarEric Auger <eric.auger@redhat.com>
Reviewed-by: default avatarRobin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20210618152059.1194210-5-jean-philippe@linaro.org


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 3cf48554

arch/arm64/mm/dma-mapping.c

+1 −1
Original line number Diff line number Diff line
@@ -50,7 +50,7 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, 


	dev->dma_coherent = coherent;

	if (iommu)

		iommu_setup_dma_ops(dev, dma_base, size);

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



#ifdef CONFIG_XEN

	if (xen_swiotlb_detect())

drivers/iommu/amd/iommu.c

+1 −1
Original line number Diff line number Diff line
@@ -1713,7 +1713,7 @@ static void amd_iommu_probe_finalize(struct device *dev) 
	/* Domains are initialized for this device - have a look what we ended up with */

	domain = iommu_get_domain_for_dev(dev);

	if (domain->type == IOMMU_DOMAIN_DMA)

		iommu_setup_dma_ops(dev, IOVA_START_PFN << PAGE_SHIFT, 0);

		iommu_setup_dma_ops(dev, 0, U64_MAX);

	else

		set_dma_ops(dev, NULL);

}

drivers/iommu/dma-iommu.c

+6 −6
Original line number Diff line number Diff line
@@ -319,16 +319,16 @@ static bool dev_is_untrusted(struct device *dev) 
 * iommu_dma_init_domain - Initialise a DMA mapping domain

 * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie()

 * @base: IOVA at which the mappable address space starts

 * @size: Size of IOVA space

 * @limit: Last address of the IOVA space

 * @dev: Device the domain is being initialised for

 *

 * @base and @size should be exact multiples of IOMMU page granularity to

 * @base and @limit + 1 should be exact multiples of IOMMU page granularity to

 * avoid rounding surprises. If necessary, we reserve the page at address 0

 * to ensure it is an invalid IOVA. It is safe to reinitialise a domain, but

 * any change which could make prior IOVAs invalid will fail.

 */

static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,

		u64 size, struct device *dev)

				 dma_addr_t limit, struct device *dev)

{

	struct iommu_dma_cookie *cookie = domain->iova_cookie;

	unsigned long order, base_pfn;
@@ -346,7 +346,7 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, 
	/* Check the domain allows at least some access to the device... */

	if (domain->geometry.force_aperture) {

		if (base > domain->geometry.aperture_end ||

		    base + size <= domain->geometry.aperture_start) {

		    limit < domain->geometry.aperture_start) {

			pr_warn("specified DMA range outside IOMMU capability\n");

			return -EFAULT;

		}
@@ -1308,7 +1308,7 @@ static const struct dma_map_ops iommu_dma_ops = { 
 * 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 size)

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

{

	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
@@ -1320,7 +1320,7 @@ void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size) 
	 * underlying IOMMU driver needs to support via the dma-iommu layer.

	 */

	if (domain->type == IOMMU_DOMAIN_DMA) {

		if (iommu_dma_init_domain(domain, dma_base, size, dev))

		if (iommu_dma_init_domain(domain, dma_base, dma_limit, dev))

			goto out_err;

		dev->dma_ops = &iommu_dma_ops;

	}

drivers/iommu/intel/iommu.c

+1 −4
Original line number Diff line number Diff line
@@ -5165,13 +5165,10 @@ static void intel_iommu_release_device(struct device *dev) 


static void intel_iommu_probe_finalize(struct device *dev)

{

	dma_addr_t base = IOVA_START_PFN << VTD_PAGE_SHIFT;

	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);

	struct dmar_domain *dmar_domain = to_dmar_domain(domain);



	if (domain && domain->type == IOMMU_DOMAIN_DMA)

		iommu_setup_dma_ops(dev, base,

				    __DOMAIN_MAX_ADDR(dmar_domain->gaw) - base);

		iommu_setup_dma_ops(dev, 0, U64_MAX);

	else

		set_dma_ops(dev, NULL);

}

include/linux/dma-iommu.h

+2 −2
Original line number Diff line number Diff line
@@ -19,7 +19,7 @@ int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base); 
void iommu_put_dma_cookie(struct iommu_domain *domain);



/* Setup call for arch DMA mapping code */

void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size);

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



/* The DMA API isn't _quite_ the whole story, though... */

/*
@@ -50,7 +50,7 @@ struct msi_msg; 
struct device;



static inline void iommu_setup_dma_ops(struct device *dev, u64 dma_base,

		u64 size)

				       u64 dma_limit)

{

}