From 6ac7dffe7cca9b259f17b2f255b0d95ee15a76fd Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Tue, 5 Nov 2024 14:14:26 -0400 Subject: [PATCH] iommu: Add a kdoc to iommu_unmap() Describe the most conservative version of the driver implementations. All drivers should support this. Many drivers support extending the range if a large page is hit, but let's not make that officially approved API. The main point is to document explicitly that split is not supported. Reviewed-by: Liviu Dudau Signed-off-by: Jason Gunthorpe Link: https://lore.kernel.org/r/3-v3-b3a5b5937f56+7bb-arm_no_split_jgg@nvidia.com Signed-off-by: Will Deacon --- drivers/iommu/iommu.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 83c8e617a2c58..19b177720d3ac 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -2586,6 +2586,20 @@ static size_t __iommu_unmap(struct iommu_domain *domain, return unmapped; } +/** + * iommu_unmap() - Remove mappings from a range of IOVA + * @domain: Domain to manipulate + * @iova: IO virtual address to start + * @size: Length of the range starting from @iova + * + * iommu_unmap() will remove a translation created by iommu_map(). It cannot + * subdivide a mapping created by iommu_map(), so it should be called with IOVA + * ranges that match what was passed to iommu_map(). The range can aggregate + * contiguous iommu_map() calls so long as no individual range is split. + * + * Returns: Number of bytes of IOVA unmapped. iova + res will be the point + * unmapping stopped. + */ size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size) {