From: Christoph Hellwig hch@lst.de
upstream 0f665b9e2a6d4cc963e6cd349d40320ed5281f95 commit.
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 hch@lst.de Reviewed-by: Max Filippov jcmvbkbc@gmail.com Tested-by: Max Filippov jcmvbkbc@gmail.com Signed-off-by: Peter Gonda pgonda@google.com --- arch/xtensa/Kconfig | 6 +- arch/xtensa/include/asm/platform.h | 27 ------- arch/xtensa/kernel/Makefile | 3 +- arch/xtensa/kernel/pci-dma.c | 121 +++-------------------------- 4 files changed, 18 insertions(+), 139 deletions(-)
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig index 8352037322df..d3a5891eff2e 100644 --- a/arch/xtensa/Kconfig +++ b/arch/xtensa/Kconfig @@ -3,8 +3,10 @@ config XTENSA def_bool y select ARCH_32BIT_OFF_T select ARCH_HAS_BINFMT_FLAT if !MMU - select ARCH_HAS_SYNC_DMA_FOR_CPU - select ARCH_HAS_SYNC_DMA_FOR_DEVICE + select ARCH_HAS_DMA_PREP_COHERENT if MMU + select ARCH_HAS_SYNC_DMA_FOR_CPU if MMU + select ARCH_HAS_SYNC_DMA_FOR_DEVICE if MMU + select ARCH_HAS_UNCACHED_SEGMENT if MMU select ARCH_USE_QUEUED_RWLOCKS select ARCH_USE_QUEUED_SPINLOCKS select ARCH_WANT_FRAME_POINTERS diff --git a/arch/xtensa/include/asm/platform.h b/arch/xtensa/include/asm/platform.h index 913826dfa838..f2c48522c5a1 100644 --- a/arch/xtensa/include/asm/platform.h +++ b/arch/xtensa/include/asm/platform.h @@ -65,31 +65,4 @@ extern void platform_calibrate_ccount (void); */ void cpu_reset(void) __attribute__((noreturn));
-/* - * Memory caching is platform-dependent in noMMU xtensa configurations. - * The following set of functions should be implemented in platform code - * in order to enable coherent DMA memory operations when CONFIG_MMU is not - * enabled. Default implementations do nothing and issue a warning. - */ - -/* - * Check whether p points to a cached memory. - */ -bool platform_vaddr_cached(const void *p); - -/* - * Check whether p points to an uncached memory. - */ -bool platform_vaddr_uncached(const void *p); - -/* - * Return pointer to an uncached view of the cached sddress p. - */ -void *platform_vaddr_to_uncached(void *p); - -/* - * Return pointer to a cached view of the uncached sddress p. - */ -void *platform_vaddr_to_cached(void *p); - #endif /* _XTENSA_PLATFORM_H */ diff --git a/arch/xtensa/kernel/Makefile b/arch/xtensa/kernel/Makefile index 6f629027ac7d..d4082c6a121b 100644 --- a/arch/xtensa/kernel/Makefile +++ b/arch/xtensa/kernel/Makefile @@ -5,10 +5,11 @@
extra-y := head.o vmlinux.lds
-obj-y := align.o coprocessor.o entry.o irq.o pci-dma.o platform.o process.o \ +obj-y := align.o coprocessor.o entry.o irq.o platform.o process.o \ ptrace.o setup.o signal.o stacktrace.o syscall.o time.o traps.o \ vectors.o
+obj-$(CONFIG_MMU) += pci-dma.o obj-$(CONFIG_PCI) += pci.o obj-$(CONFIG_MODULES) += xtensa_ksyms.o module.o obj-$(CONFIG_FUNCTION_TRACER) += mcount.o 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 */