@@ -1119,7 +1119,6 @@ config DMA_PERDEV_COHERENT
config DMA_NONCOHERENT
bool
- select ARCH_HAS_DMA_MMAP_PGPROT
select ARCH_HAS_SYNC_DMA_FOR_DEVICE
select ARCH_HAS_UNCACHED_SEGMENT
select NEED_DMA_MAP_STATE
@@ -65,14 +65,6 @@ long arch_dma_coherent_to_pfn(struct device *dev, void *cpu_addr,
return page_to_pfn(virt_to_page(cached_kernel_address(cpu_addr)));
}
-pgprot_t arch_dma_mmap_pgprot(struct device *dev, pgprot_t prot,
- unsigned long attrs)
-{
- if (attrs & DMA_ATTR_WRITE_COMBINE)
- return pgprot_writecombine(prot);
- return pgprot_noncached(prot);
-}
-
static inline void dma_sync_virt(void *addr, size_t size,
enum dma_data_direction dir)
{
Mips uses the KSEG1 kernel memory segment do map dma coherent allocations for non-coherent devices as uncachable, and does not have any kind of special support for DMA_ATTR_WRITE_COMBINE in the allocation path. Thus supporting DMA_ATTR_WRITE_COMBINE in dma_mmap_attrs will lead to multiple mappings with different caching attributes. Fixes: 8c172467be36 ("MIPS: Add implementation of dma_map_ops.mmap()") Signed-off-by: Christoph Hellwig <hch@lst.de> --- arch/mips/Kconfig | 1 - arch/mips/mm/dma-noncoherent.c | 8 -------- 2 files changed, 9 deletions(-)