Messages in this thread Patch in this message | | | From | Nadav Amit <> | Subject | [PATCH v3 4/6] iommu: Factor iommu_iotlb_gather_is_disjoint() out | Date | Mon, 7 Jun 2021 11:25:39 -0700 |
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From: Nadav Amit <namit@vmware.com>
Refactor iommu_iotlb_gather_add_page() and factor out the logic that detects whether IOTLB gather range and a new range are disjoint. To be used by the next patch that implements different gathering logic for AMD.
Cc: Joerg Roedel <joro@8bytes.org> Cc: Will Deacon <will@kernel.org> Cc: Jiajun Cao <caojiajun@vmware.com> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Lu Baolu <baolu.lu@linux.intel.com> Cc: iommu@lists.linux-foundation.org Cc: linux-kernel@vger.kernel.org> Signed-off-by: Nadav Amit <namit@vmware.com> --- include/linux/iommu.h | 41 +++++++++++++++++++++++++++++++++-------- 1 file changed, 33 insertions(+), 8 deletions(-)
diff --git a/include/linux/iommu.h b/include/linux/iommu.h index f254c62f3720..b5a2bfc68fb0 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -497,6 +497,28 @@ static inline void iommu_iotlb_sync(struct iommu_domain *domain, iommu_iotlb_gather_init(iotlb_gather); } +/** + * iommu_iotlb_gather_is_disjoint - Checks whether a new range is disjoint + * + * @gather: TLB gather data + * @iova: start of page to invalidate + * @size: size of page to invalidate + * + * Helper for IOMMU drivers to check whether a new range is and the gathered + * range are disjoint. For many IOMMUs, flushing the IOMMU in this case is + * better than merging the two, which might lead to unnecessary invalidations. + */ +static inline +bool iommu_iotlb_gather_is_disjoint(struct iommu_iotlb_gather *gather, + unsigned long iova, size_t size) +{ + unsigned long start = iova, end = start + size - 1; + + return gather->end != 0 && + (end + 1 < gather->start || start > gather->end + 1); +} + + /** * iommu_iotlb_gather_add_range - Gather for address-based TLB invalidation * @gather: TLB gather data @@ -533,20 +555,16 @@ static inline void iommu_iotlb_gather_add_page(struct iommu_domain *domain, struct iommu_iotlb_gather *gather, unsigned long iova, size_t size) { - unsigned long start = iova, end = start + size - 1; - /* * If the new page is disjoint from the current range or is mapped at * a different granularity, then sync the TLB so that the gather * structure can be rewritten. */ - if (gather->pgsize != size || - end + 1 < gather->start || start > gather->end + 1) { - if (gather->pgsize) - iommu_iotlb_sync(domain, gather); - gather->pgsize = size; - } + if ((gather->pgsize && gather->pgsize != size) || + iommu_iotlb_gather_is_disjoint(gather, iova, size)) + iommu_iotlb_sync(domain, gather); + gather->pgsize = size; iommu_iotlb_gather_add_range(gather, iova, size); } @@ -730,6 +748,13 @@ static inline void iommu_iotlb_sync(struct iommu_domain *domain, { } +static inline +bool iommu_iotlb_gather_is_disjoint(struct iommu_iotlb_gather *gather, + unsigned long iova, size_t size) +{ + return false; +} + static inline void iommu_iotlb_gather_add_range(struct iommu_iotlb_gather *gather, unsigned long iova, size_t size) { -- 2.25.1
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