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| author | Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> | 2018-07-30 18:26:36 +0200 |
|---|---|---|
| committer | Vineet Gupta <vgupta@synopsys.com> | 2018-09-04 22:21:38 +0200 |
| commit | dd45210b6dd4f1512eafcc41774154ebb762360f (patch) | |
| tree | 7ec04d741bc790b2bafec213a8527883229cfaaf /arch | |
| parent | ARC: IOC: panic if both IOC and ZONE_HIGHMEM enabled (diff) | |
| download | linux-dd45210b6dd4f1512eafcc41774154ebb762360f.tar.xz linux-dd45210b6dd4f1512eafcc41774154ebb762360f.zip | |
ARC: don't check for HIGHMEM pages in arch_dma_alloc
__GFP_HIGHMEM flag is cleared by upper layer functions
(in include/linux/dma-mapping.h) so we'll never get a
__GFP_HIGHMEM flag in arch_dma_alloc gfp argument.
That's why alloc_pages will never return highmem page
here.
Get rid of highmem pages handling and cleanup arch_dma_alloc
and arch_dma_free functions.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arc/mm/dma.c | 32 |
1 files changed, 14 insertions, 18 deletions
diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c index c0b49399225d..c75d5c3470e3 100644 --- a/arch/arc/mm/dma.c +++ b/arch/arc/mm/dma.c @@ -24,30 +24,29 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, struct page *page; phys_addr_t paddr; void *kvaddr; - int need_coh = 1, need_kvaddr = 0; + bool need_coh = !(attrs & DMA_ATTR_NON_CONSISTENT); + + /* + * __GFP_HIGHMEM flag is cleared by upper layer functions + * (in include/linux/dma-mapping.h) so we should never get a + * __GFP_HIGHMEM here. + */ + BUG_ON(gfp & __GFP_HIGHMEM); page = alloc_pages(gfp, order); if (!page) return NULL; - if (attrs & DMA_ATTR_NON_CONSISTENT) - need_coh = 0; - - /* - * - A coherent buffer needs MMU mapping to enforce non-cachability - * - A highmem page needs a virtual handle (hence MMU mapping) - * independent of cachability - */ - if (PageHighMem(page) || need_coh) - need_kvaddr = 1; - /* This is linear addr (0x8000_0000 based) */ paddr = page_to_phys(page); *dma_handle = paddr; - /* This is kernel Virtual address (0x7000_0000 based) */ - if (need_kvaddr) { + /* + * A coherent buffer needs MMU mapping to enforce non-cachability. + * kvaddr is kernel Virtual address (0x7000_0000 based). + */ + if (need_coh) { kvaddr = ioremap_nocache(paddr, size); if (kvaddr == NULL) { __free_pages(page, order); @@ -78,11 +77,8 @@ void arch_dma_free(struct device *dev, size_t size, void *vaddr, { phys_addr_t paddr = dma_handle; struct page *page = virt_to_page(paddr); - int is_non_coh = 1; - - is_non_coh = (attrs & DMA_ATTR_NON_CONSISTENT); - if (PageHighMem(page) || !is_non_coh) + if (!(attrs & DMA_ATTR_NON_CONSISTENT)) iounmap((void __force __iomem *)vaddr); __free_pages(page, get_order(size)); |