From 6137e4166004e2ec383ac05d5ca15831f4668806 Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Wed, 14 Feb 2018 16:12:54 -0800 Subject: xtensa: support DMA buffers in high memory If a DMA buffer is allocated in high memory and kernel mapping is required use dma_common_contiguous_remap to map buffer to the vmalloc region and dma_common_free_remap to unmap it. Signed-off-by: Max Filippov --- arch/xtensa/kernel/pci-dma.c | 40 ++++++++++++++++++++++++++++++---------- 1 file changed, 30 insertions(+), 10 deletions(-) (limited to 'arch/xtensa/kernel/pci-dma.c') diff --git a/arch/xtensa/kernel/pci-dma.c b/arch/xtensa/kernel/pci-dma.c index 623720a11143..732631ce250f 100644 --- a/arch/xtensa/kernel/pci-dma.c +++ b/arch/xtensa/kernel/pci-dma.c @@ -16,6 +16,7 @@ */ #include +#include #include #include #include @@ -123,7 +124,7 @@ static void *xtensa_dma_alloc(struct device *dev, size_t size, unsigned long attrs) { unsigned long ret; - unsigned long uncached = 0; + unsigned long uncached; unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; struct page *page = NULL; @@ -144,15 +145,27 @@ static void *xtensa_dma_alloc(struct device *dev, size_t size, if (!page) return NULL; - ret = (unsigned long)page_address(page); + *handle = phys_to_dma(dev, page_to_phys(page)); - /* We currently don't support coherent memory outside KSEG */ +#ifdef CONFIG_MMU + if (PageHighMem(page)) { + void *p; + p = dma_common_contiguous_remap(page, size, VM_MAP, + pgprot_noncached(PAGE_KERNEL), + __builtin_return_address(0)); + if (!p) { + if (!dma_release_from_contiguous(dev, page, count)) + __free_pages(page, get_order(size)); + } + return p; + } +#endif + ret = (unsigned long)page_address(page); BUG_ON(ret < XCHAL_KSEG_CACHED_VADDR || ret > XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE - 1); uncached = ret + XCHAL_KSEG_BYPASS_VADDR - XCHAL_KSEG_CACHED_VADDR; - *handle = virt_to_bus((void *)ret); __invalidate_dcache_range(ret, size); return (void *)uncached; @@ -161,13 +174,20 @@ static void *xtensa_dma_alloc(struct device *dev, size_t size, static void xtensa_dma_free(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle, unsigned long attrs) { - unsigned long addr = (unsigned long)vaddr + - XCHAL_KSEG_CACHED_VADDR - XCHAL_KSEG_BYPASS_VADDR; - struct page *page = virt_to_page(addr); unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; - - BUG_ON(addr < XCHAL_KSEG_CACHED_VADDR || - addr > XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE - 1); + unsigned long addr = (unsigned long)vaddr; + struct page *page; + + if (addr >= XCHAL_KSEG_BYPASS_VADDR && + addr - XCHAL_KSEG_BYPASS_VADDR < XCHAL_KSEG_SIZE) { + addr += XCHAL_KSEG_CACHED_VADDR - XCHAL_KSEG_BYPASS_VADDR; + page = virt_to_page(addr); + } else { +#ifdef CONFIG_MMU + dma_common_free_remap(vaddr, size, VM_MAP); +#endif + page = pfn_to_page(PHYS_PFN(dma_to_phys(dev, dma_handle))); + } if (!dma_release_from_contiguous(dev, page, count)) __free_pages(page, get_order(size)); -- cgit