[RFC 06/16] iommu/dma: Implement link/unlink page callbacks

Leon Romanovsky
2024-03-05T13:33:27Z

Add an implementation of link/unlink interface to perform in map/unmap
pages in fast patch for pre-allocated IOVA.

Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
drivers/iommu/dma-iommu.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index dbdd373a609a..b683c4a4e9f8 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -1752,6 +1752,21 @@ static void iommu_dma_free_iova(struct device *dev, dma_addr_t iova,
__iommu_dma_free_iova(cookie, iova, size, &iotlb_gather);
}

+static dma_addr_t iommu_dma_link_range(struct device *dev, struct page *page,
+ unsigned long offset, dma_addr_t iova,
+ size_t size, enum dma_data_direction dir,
+ unsigned long attrs)
+{
+ return __iommu_dma_map_pages(dev, page, offset, iova, size, dir, attrs);
+}
+
+static void iommu_dma_unlink_range(struct device *dev, dma_addr_t addr,
+ size_t size, enum dma_data_direction dir,
+ unsigned long attrs)
+{
+ __iommu_dma_unmap_pages(dev, addr, size, dir, attrs, false);
+}
+
static const struct dma_map_ops iommu_dma_ops = {
.flags = DMA_F_PCI_P2PDMA_SUPPORTED,
.alloc = iommu_dma_alloc,
@@ -1776,6 +1791,8 @@ static const struct dma_map_ops iommu_dma_ops = {
.opt_mapping_size = iommu_dma_opt_mapping_size,
.alloc_iova = iommu_dma_alloc_iova,
.free_iova = iommu_dma_free_iova,
+ .link_range = iommu_dma_link_range,
+ .unlink_range = iommu_dma_unlink_range,
};

/*
--
2.44.0