From 0f665b9e2a6d4cc963e6cd349d40320ed5281f95 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 29 Oct 2019 10:53:30 +0100 Subject: xtensa: use the generic uncached segment support Switch xtensa over to use the generic uncached support, and thus the generic implementations of dma_alloc_* and dma_alloc_*, which also gains support for mmaping DMA memory. The non-working nommu DMA support has been disabled, but could be re-enabled easily if platforms that actually have an uncached segment show up. Signed-off-by: Christoph Hellwig Reviewed-by: Max Filippov Tested-by: Max Filippov --- arch/xtensa/kernel/pci-dma.c | 121 +++++-------------------------------------- 1 file changed, 12 insertions(+), 109 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 154979d62b73..1c82e21de4f6 100644 --- a/arch/xtensa/kernel/pci-dma.c +++ b/arch/xtensa/kernel/pci-dma.c @@ -81,122 +81,25 @@ void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr, } } -#ifdef CONFIG_MMU -bool platform_vaddr_cached(const void *p) -{ - unsigned long addr = (unsigned long)p; - - return addr >= XCHAL_KSEG_CACHED_VADDR && - addr - XCHAL_KSEG_CACHED_VADDR < XCHAL_KSEG_SIZE; -} - -bool platform_vaddr_uncached(const void *p) -{ - unsigned long addr = (unsigned long)p; - - return addr >= XCHAL_KSEG_BYPASS_VADDR && - addr - XCHAL_KSEG_BYPASS_VADDR < XCHAL_KSEG_SIZE; -} - -void *platform_vaddr_to_uncached(void *p) -{ - return p + XCHAL_KSEG_BYPASS_VADDR - XCHAL_KSEG_CACHED_VADDR; -} - -void *platform_vaddr_to_cached(void *p) -{ - return p + XCHAL_KSEG_CACHED_VADDR - XCHAL_KSEG_BYPASS_VADDR; -} -#else -bool __attribute__((weak)) platform_vaddr_cached(const void *p) -{ - WARN_ONCE(1, "Default %s implementation is used\n", __func__); - return true; -} - -bool __attribute__((weak)) platform_vaddr_uncached(const void *p) -{ - WARN_ONCE(1, "Default %s implementation is used\n", __func__); - return false; -} - -void __attribute__((weak)) *platform_vaddr_to_uncached(void *p) +void arch_dma_prep_coherent(struct page *page, size_t size) { - WARN_ONCE(1, "Default %s implementation is used\n", __func__); - return p; -} - -void __attribute__((weak)) *platform_vaddr_to_cached(void *p) -{ - WARN_ONCE(1, "Default %s implementation is used\n", __func__); - return p; + __invalidate_dcache_range((unsigned long)page_address(page), size); } -#endif /* - * Note: We assume that the full memory space is always mapped to 'kseg' - * Otherwise we have to use page attributes (not implemented). + * Memory caching is platform-dependent in noMMU xtensa configurations. + * The following two functions should be implemented in platform code + * in order to enable coherent DMA memory operations when CONFIG_MMU is not + * enabled. */ - -void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, - gfp_t flag, unsigned long attrs) -{ - unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; - struct page *page = NULL; - - /* ignore region speicifiers */ - - flag &= ~(__GFP_DMA | __GFP_HIGHMEM); - - if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff)) - flag |= GFP_DMA; - - if (gfpflags_allow_blocking(flag)) - page = dma_alloc_from_contiguous(dev, count, get_order(size), - flag & __GFP_NOWARN); - - if (!page) - page = alloc_pages(flag | __GFP_ZERO, get_order(size)); - - if (!page) - return NULL; - - *handle = phys_to_dma(dev, page_to_phys(page)); - #ifdef CONFIG_MMU - if (PageHighMem(page)) { - void *p; - - p = dma_common_contiguous_remap(page, size, - 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 - BUG_ON(!platform_vaddr_cached(page_address(page))); - __invalidate_dcache_range((unsigned long)page_address(page), size); - return platform_vaddr_to_uncached(page_address(page)); +void *uncached_kernel_address(void *p) +{ + return p + XCHAL_KSEG_BYPASS_VADDR - XCHAL_KSEG_CACHED_VADDR; } -void arch_dma_free(struct device *dev, size_t size, void *vaddr, - dma_addr_t dma_handle, unsigned long attrs) +void *cached_kernel_address(void *p) { - unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; - struct page *page; - - if (platform_vaddr_uncached(vaddr)) { - page = virt_to_page(platform_vaddr_to_cached(vaddr)); - } else { -#ifdef CONFIG_MMU - dma_common_free_remap(vaddr, size); -#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)); + return p + XCHAL_KSEG_CACHED_VADDR - XCHAL_KSEG_BYPASS_VADDR; } +#endif /* CONFIG_MMU */ -- cgit