Commit f7403abf authored by Robin Murphy's avatar Robin Murphy Committed by Joerg Roedel
Browse files

iommu/io-pgtable: Abstract iommu_iotlb_gather access 



Previously io-pgtable merely passed the iommu_iotlb_gather pointer
through to helpers, but now it has grown its own direct dereference.
This turns out to break the build for !IOMMU_API configs where the
structure only has a dummy definition. It will probably also crash
drivers who don't use the gather mechanism and simply pass in NULL.

Wrap this dereference in a suitable helper which can both be stubbed
out for !IOMMU_API and encapsulate a NULL check otherwise.

Fixes: 7a7c5bad ("iommu: Indicate queued flushes via gather data")
Reported-by: default avatarkernel test robot <lkp@intel.com>
Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/83672ee76f6405c82845a55c148fa836f56fbbc1.1629465282.git.robin.murphy@arm.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 452e69b5

drivers/iommu/io-pgtable-arm-v7s.c

+1 −1
Original line number Diff line number Diff line
@@ -700,7 +700,7 @@ static size_t __arm_v7s_unmap(struct arm_v7s_io_pgtable *data, 
						ARM_V7S_BLOCK_SIZE(lvl + 1));

				ptep = iopte_deref(pte[i], lvl, data);

				__arm_v7s_free_table(ptep, lvl + 1, data);

			} else if (!gather->queued) {

			} else if (!iommu_iotlb_gather_queued(gather)) {

				io_pgtable_tlb_add_page(iop, gather, iova, blk_size);

			}

			iova += blk_size;

drivers/iommu/io-pgtable-arm.c

+1 −1
Original line number Diff line number Diff line
@@ -638,7 +638,7 @@ static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable *data, 
				io_pgtable_tlb_flush_walk(iop, iova + i * size, size,

							  ARM_LPAE_GRANULE(data));

				__arm_lpae_free_pgtable(data, lvl + 1, iopte_deref(pte, data));

			} else if (!gather->queued) {

			} else if (!iommu_iotlb_gather_queued(gather)) {

				io_pgtable_tlb_add_page(iop, gather, iova + i * size, size);

			}

include/linux/iommu.h

+10 −0
Original line number Diff line number Diff line
@@ -548,6 +548,11 @@ static inline void iommu_iotlb_gather_add_page(struct iommu_domain *domain, 
		gather->start = start;

}



static inline bool iommu_iotlb_gather_queued(struct iommu_iotlb_gather *gather)

{

	return gather && gather->queued;

}



/* PCI device grouping function */

extern struct iommu_group *pci_device_group(struct device *dev);

/* Generic device grouping function */
@@ -896,6 +901,11 @@ static inline void iommu_iotlb_gather_add_page(struct iommu_domain *domain, 
{

}



static inline bool iommu_iotlb_gather_queued(struct iommu_iotlb_gather *gather)

{

	return false;

}



static inline void iommu_device_unregister(struct iommu_device *iommu)

{

}