From 2cc15e802b250a11ece57ea54f82993cf3430867 Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Wed, 11 Jul 2018 14:33:41 -0700 Subject: xtensa: platform-specific handling of coherent memory Memory layout is not fixed for noMMU xtensa configurations. Platforms that need to use coherent DMA should implement platform_vaddr_* helpers that check address type (cached/uncached) and convert addresses between these types. Signed-off-by: Max Filippov --- arch/xtensa/kernel/pci-dma.c | 73 +++++++++++++++++++++++++++++++++++--------- 1 file changed, 58 insertions(+), 15 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 5c8a67fc3aa1..fe3343ddccaf 100644 --- a/arch/xtensa/kernel/pci-dma.c +++ b/arch/xtensa/kernel/pci-dma.c @@ -24,6 +24,7 @@ #include #include #include +#include static void do_cache_op(phys_addr_t paddr, size_t size, void (*fn)(unsigned long, unsigned long)) @@ -84,6 +85,58 @@ 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) +{ + 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; +} +#endif + /* * Note: We assume that the full memory space is always mapped to 'kseg' * Otherwise we have to use page attributes (not implemented). @@ -92,8 +145,6 @@ void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr, void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t flag, unsigned long attrs) { - unsigned long ret; - unsigned long uncached; unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; struct page *page = NULL; @@ -134,29 +185,21 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, 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; - __invalidate_dcache_range(ret, size); - - return (void *)uncached; + 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 arch_dma_free(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle, unsigned long attrs) { unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; - unsigned long addr = (unsigned long)vaddr; struct page *page; if (attrs & DMA_ATTR_NO_KERNEL_MAPPING) { page = vaddr; - } else 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 if (platform_vaddr_uncached(vaddr)) { + page = virt_to_page(platform_vaddr_to_cached(vaddr)); } else { #ifdef CONFIG_MMU dma_common_free_remap(vaddr, size, VM_MAP); -- cgit