[PATCH 16/18] dma-mapping: add new {alloc,free}_noncoherent dma_map_ops methods
From: Christoph Hellwig <hch@lst.de>
Date: 2020-09-15 22:19:49
Also in:
alsa-devel, linux-arm-kernel, linux-doc, linux-iommu, linux-media, linux-mips, linux-mm, linux-samsung-soc, linux-scsi, lkml, nouveau
Subsystem:
dma mapping helpers, the rest · Maintainers:
Marek Szyprowski, Linus Torvalds
This will allow IOMMU drivers to allocate non-contigous memory and return a vmapped virtual address. Signed-off-by: Christoph Hellwig <hch@lst.de> --- include/linux/dma-mapping.h | 5 +++++ kernel/dma/mapping.c | 33 +++++++++++++++++++++++++++------ 2 files changed, 32 insertions(+), 6 deletions(-)
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index bf592cf0db4acb..b4b5d75260d6dc 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h@@ -80,6 +80,11 @@ struct dma_map_ops { gfp_t gfp); void (*free_pages)(struct device *dev, size_t size, struct page *vaddr, dma_addr_t dma_handle, enum dma_data_direction dir); + void* (*alloc_noncoherent)(struct device *dev, size_t size, + dma_addr_t *dma_handle, enum dma_data_direction dir, + gfp_t gfp); + void (*free_noncoherent)(struct device *dev, size_t size, void *vaddr, + dma_addr_t dma_handle, enum dma_data_direction dir); int (*mmap)(struct device *, struct vm_area_struct *, void *, dma_addr_t, size_t, unsigned long attrs);
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index 6f86c925b8251d..8614d7d2ee59a9 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c@@ -502,19 +502,40 @@ EXPORT_SYMBOL_GPL(dma_free_pages); void *dma_alloc_noncoherent(struct device *dev, size_t size, dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp) { - struct page *page; + const struct dma_map_ops *ops = get_dma_ops(dev); + void *vaddr; - page = dma_alloc_pages(dev, size, dma_handle, dir, gfp); - if (!page) - return NULL; - return page_address(page); + if (!ops || !ops->alloc_noncoherent) { + struct page *page; + + page = dma_alloc_pages(dev, size, dma_handle, dir, gfp); + if (!page) + return NULL; + return page_address(page); + } + + size = PAGE_ALIGN(size); + vaddr = ops->alloc_noncoherent(dev, size, dma_handle, dir, gfp); + if (vaddr) + debug_dma_map_page(dev, virt_to_page(vaddr), 0, size, dir, + *dma_handle); + return vaddr; } EXPORT_SYMBOL_GPL(dma_alloc_noncoherent); void dma_free_noncoherent(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle, enum dma_data_direction dir) { - dma_free_pages(dev, size, virt_to_page(vaddr), dma_handle, dir); + const struct dma_map_ops *ops = get_dma_ops(dev); + + if (!ops || !ops->free_noncoherent) { + dma_free_pages(dev, size, virt_to_page(vaddr), dma_handle, dir); + return; + } + + size = PAGE_ALIGN(size); + debug_dma_unmap_page(dev, dma_handle, size, dir); + ops->free_noncoherent(dev, size, vaddr, dma_handle, dir); } EXPORT_SYMBOL_GPL(dma_free_noncoherent);
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2.28.0