[PATCH 07/25] nds32: remove the broken kmap code in nds32_dma_map_sg
From: Christoph Hellwig <hidden>
Date: 2018-05-22 12:16:48
Also in:
linux-arch, linux-arm-kernel, linux-iommu, linux-sh, lkml, sparclinux
Subsystem:
the rest · Maintainer:
Linus Torvalds
nds32_dma_map_sg is the only of the various DMA operations that tries to deal with highmem (the single page variants and SG sync routines are missing, SG unmap is entirely unimplemented), and it does so without taking into account S/G list items that are bigger than a page, which are legal and can happen frequently. Remove this code for now - if highmem support on nds32 becomes a real thing it needs to be added back as a loop over pages in the newly consolidated code that deals with all operations. Signed-off-by: Christoph Hellwig <redacted> --- arch/nds32/kernel/dma.c | 21 +++------------------ 1 file changed, 3 insertions(+), 18 deletions(-)
diff --git a/arch/nds32/kernel/dma.c b/arch/nds32/kernel/dma.c
index d291800fc621..e1bf7206e015 100644
--- a/arch/nds32/kernel/dma.c
+++ b/arch/nds32/kernel/dma.c@@ -393,24 +393,9 @@ static int nds32_dma_map_sg(struct device *dev, struct scatterlist *sg, int i; for (i = 0; i < nents; i++, sg++) { - void *virt; - unsigned long pfn; - struct page *page = sg_page(sg); - - sg->dma_address = sg_phys(sg); - pfn = page_to_pfn(page) + sg->offset / PAGE_SIZE; - page = pfn_to_page(pfn); - if (PageHighMem(page)) { - virt = kmap_atomic(page); - consistent_sync(virt, sg->length, dir, FOR_CPU); - kunmap_atomic(virt); - } else { - if (sg->offset > PAGE_SIZE) - panic("sg->offset:%08x > PAGE_SIZE\n", - sg->offset); - virt = page_address(page) + sg->offset; - consistent_sync(virt, sg->length, dir, FOR_CPU); - } + char *virt = + page_address((struct page *)sg->page_link) + sg->offset; + consistent_sync(virt, sg->length, dir, FOR_CPU); } return nents; }
--
2.17.0