From: Robin Murphy Date: Fri, 23 Jul 2021 02:32:05 -0700 Subject: iommu: Improve iommu_iotlb_gather helpers Git-commit: 3136895cc5b665c1ab406d78f90c0700a3551e74 Patch-mainline: v5.15-rc1 References: bsc#1192202 The Mediatek driver is not the only one which might want a basic address-based gathering behaviour, so although it's arguably simple enough to open-code, let's factor it out for the sake of cleanliness. Let's also take this opportunity to document the intent of these helpers for clarity. Cc: Joerg Roedel Cc: Will Deacon Cc: Jiajun Cao Cc: Robin Murphy Cc: Lu Baolu Cc: iommu@lists.linux-foundation.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Robin Murphy Signed-off-by: Nadav Amit Link: https://lore.kernel.org/r/20210723093209.714328-4-namit@vmware.com Signed-off-by: Joerg Roedel --- drivers/iommu/mtk_iommu.c | 6 +----- include/linux/iommu.h | 38 +++++++++++++++++++++++++++++++++----- 2 files changed, 34 insertions(+), 10 deletions(-) --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -520,12 +520,8 @@ static size_t mtk_iommu_unmap(struct iom struct iommu_iotlb_gather *gather) { struct mtk_iommu_domain *dom = to_mtk_domain(domain); - unsigned long end = iova + size - 1; - if (gather->start > iova) - gather->start = iova; - if (gather->end < end) - gather->end = end; + iommu_iotlb_gather_add_range(gather, iova, size); return dom->iop->unmap(dom->iop, iova, size, gather); } --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -506,6 +506,38 @@ static inline void iommu_iotlb_sync(stru iommu_iotlb_gather_init(iotlb_gather); } +/** + * iommu_iotlb_gather_add_range - Gather for address-based TLB invalidation + * @gather: TLB gather data + * @iova: start of page to invalidate + * @size: size of page to invalidate + * + * Helper for IOMMU drivers to build arbitrarily-sized invalidation commands + * where only the address range matters, and simply minimising intermediate + * syncs is preferred. + */ +static inline void iommu_iotlb_gather_add_range(struct iommu_iotlb_gather *gather, + unsigned long iova, size_t size) +{ + unsigned long end = iova + size - 1; + + if (gather->start > iova) + gather->start = iova; + if (gather->end < end) + gather->end = end; +} + +/** + * iommu_iotlb_gather_add_page - Gather for page-based TLB invalidation + * @domain: IOMMU domain to be invalidated + * @gather: TLB gather data + * @iova: start of page to invalidate + * @size: size of page to invalidate + * + * Helper for IOMMU drivers to build invalidation commands based on individual + * pages, or with page size/table level hints which cannot be gathered if they + * differ. + */ static inline void iommu_iotlb_gather_add_page(struct iommu_domain *domain, struct iommu_iotlb_gather *gather, unsigned long iova, size_t size) @@ -524,11 +556,7 @@ static inline void iommu_iotlb_gather_ad gather->pgsize = size; } - if (gather->end < end) - gather->end = end; - - if (gather->start > start) - gather->start = start; + iommu_iotlb_gather_add_range(gather, iova, size); } /* PCI device grouping function */