Add a new dma_map_ops implementation that uses dma-direct for the address mapping of streaming mappings, and which requires arch-specific implemenations of coherent allocate/free. Architectures have to provide flushing helpers to ownership trasnfers to the device and/or CPU, and can provide optional implementations of the coherent mmap functionality, and the cache_flush routines for non-coherent long term allocations. Signed-off-by: Christoph Hellwig <hch at lst.de> --- MAINTAINERS | 2 + include/asm-generic/dma-mapping.h | 9 +++ include/linux/dma-direct.h | 7 +- include/linux/dma-mapping.h | 1 + include/linux/dma-noncoherent.h | 47 ++++++++++++++ lib/Kconfig | 20 ++++++ lib/Makefile | 1 + lib/dma-direct.c | 8 +-- lib/dma-noncoherent.c | 102 ++++++++++++++++++++++++++++++ 9 files changed, 192 insertions(+), 5 deletions(-) create mode 100644 include/linux/dma-noncoherent.h create mode 100644 lib/dma-noncoherent.c diff --git a/MAINTAINERS b/MAINTAINERS index 79bb02ff812f..08d0d15d4958 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -4334,12 +4334,14 @@ W: http://git.infradead.org/users/hch/dma-mapping.git S: Supported F: lib/dma-debug.c F: lib/dma-direct.c +F: lib/dma-noncoherent.c F: lib/dma-virt.c F: drivers/base/dma-mapping.c F: drivers/base/dma-coherent.c F: include/asm-generic/dma-mapping.h F: include/linux/dma-direct.h F: include/linux/dma-mapping.h +F: include/linux/dma-noncoherent.h DME1737 HARDWARE MONITOR DRIVER M: Juerg Haefliger <juergh at gmail.com> diff --git a/include/asm-generic/dma-mapping.h b/include/asm-generic/dma-mapping.h index 880a292d792f..ad2868263867 100644 --- a/include/asm-generic/dma-mapping.h +++ b/include/asm-generic/dma-mapping.h @@ -4,7 +4,16 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus) { + /* + * Use the non-coherent ops if available. If an architecture wants a + * more fine-grained selection of operations it will have to implement + * get_arch_dma_ops itself or use the per-device dma_ops. + */ +#ifdef CONFIG_DMA_NONCOHERENT_OPS + return &dma_noncoherent_ops; +#else return &dma_direct_ops; +#endif } #endif /* _ASM_GENERIC_DMA_MAPPING_H */ diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h index 53ad6a47f513..8d9f33febde5 100644 --- a/include/linux/dma-direct.h +++ b/include/linux/dma-direct.h @@ -59,6 +59,11 @@ void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs); void dma_direct_free(struct device *dev, size_t size, void *cpu_addr, dma_addr_t dma_addr, unsigned long attrs); +dma_addr_t dma_direct_map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, enum dma_data_direction dir, + unsigned long attrs); +int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents, + enum dma_data_direction dir, unsigned long attrs); int dma_direct_supported(struct device *dev, u64 mask); - +int dma_direct_mapping_error(struct device *dev, dma_addr_t dma_addr); #endif /* _LINUX_DMA_DIRECT_H */ diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 25a9a2b04f78..4be070df5fc5 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -136,6 +136,7 @@ struct dma_map_ops { }; extern const struct dma_map_ops dma_direct_ops; +extern const struct dma_map_ops dma_noncoherent_ops; extern const struct dma_map_ops dma_virt_ops; #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1)) diff --git a/include/linux/dma-noncoherent.h b/include/linux/dma-noncoherent.h new file mode 100644 index 000000000000..10b2654d549b --- /dev/null +++ b/include/linux/dma-noncoherent.h @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_DMA_NONCOHERENT_H +#define _LINUX_DMA_NONCOHERENT_H 1 + +#include <linux/dma-mapping.h> + +void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, + gfp_t gfp, unsigned long attrs); +void arch_dma_free(struct device *dev, size_t size, void *cpu_addr, + dma_addr_t dma_addr, unsigned long attrs); + +#ifdef CONFIG_DMA_NONCOHERENT_MMAP +int arch_dma_mmap(struct device *dev, struct vm_area_struct *vma, + void *cpu_addr, dma_addr_t dma_addr, size_t size, + unsigned long attrs); +#else +#define arch_dma_mmap NULL +#endif /* CONFIG_DMA_NONCOHERENT_MMAP */ + +#ifdef CONFIG_DMA_NONCOHERENT_CACHE_SYNC +void arch_dma_cache_sync(struct device *dev, void *vaddr, size_t size, + enum dma_data_direction direction); +#else +#define arch_dma_cache_sync NULL +#endif /* CONFIG_DMA_NONCOHERENT_CACHE_SYNC */ + +#ifdef CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE +void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr, + size_t size, enum dma_data_direction dir); +#else +static inline void arch_sync_dma_for_device(struct device *dev, + phys_addr_t paddr, size_t size, enum dma_data_direction dir) +{ +} +#endif /* ARCH_HAS_SYNC_DMA_FOR_DEVICE */ + +#ifdef CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU +void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr, + size_t size, enum dma_data_direction dir); +#else +static inline void arch_sync_dma_for_cpu(struct device *dev, + phys_addr_t paddr, size_t size, enum dma_data_direction dir) +{ +} +#endif /* ARCH_HAS_SYNC_DMA_FOR_CPU */ + +#endif /* _LINUX_DMA_NONCOHERENT_H */ diff --git a/lib/Kconfig b/lib/Kconfig index 6c4e9d0ce5d1..7a913937888b 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -441,10 +441,30 @@ config ARCH_DMA_ADDR_T_64BIT config IOMMU_HELPER bool +config ARCH_HAS_SYNC_DMA_FOR_DEVICE + bool + +config ARCH_HAS_SYNC_DMA_FOR_CPU + bool + select NEED_DMA_MAP_STATE + config DMA_DIRECT_OPS bool depends on HAS_DMA +config DMA_NONCOHERENT_OPS + bool + depends on HAS_DMA + select DMA_DIRECT_OPS + +config DMA_NONCOHERENT_MMAP + bool + depends on DMA_NONCOHERENT_OPS + +config DMA_NONCOHERENT_CACHE_SYNC + bool + depends on DMA_NONCOHERENT_OPS + config DMA_VIRT_OPS bool depends on HAS_DMA diff --git a/lib/Makefile b/lib/Makefile index 94203b5eecd4..9f18c8152281 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -30,6 +30,7 @@ lib-$(CONFIG_PRINTK) += dump_stack.o lib-$(CONFIG_MMU) += ioremap.o lib-$(CONFIG_SMP) += cpumask.o lib-$(CONFIG_DMA_DIRECT_OPS) += dma-direct.o +lib-$(CONFIG_DMA_NONCOHERENT_OPS) += dma-noncoherent.o lib-$(CONFIG_DMA_VIRT_OPS) += dma-virt.o lib-y += kobject.o klist.o diff --git a/lib/dma-direct.c b/lib/dma-direct.c index df9e726e0712..b824eb218782 100644 --- a/lib/dma-direct.c +++ b/lib/dma-direct.c @@ -128,7 +128,7 @@ void dma_direct_free(struct device *dev, size_t size, void *cpu_addr, free_pages((unsigned long)cpu_addr, page_order); } -static dma_addr_t dma_direct_map_page(struct device *dev, struct page *page, +dma_addr_t dma_direct_map_page(struct device *dev, struct page *page, unsigned long offset, size_t size, enum dma_data_direction dir, unsigned long attrs) { @@ -139,8 +139,8 @@ static dma_addr_t dma_direct_map_page(struct device *dev, struct page *page, return dma_addr; } -static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, - int nents, enum dma_data_direction dir, unsigned long attrs) +int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents, + enum dma_data_direction dir, unsigned long attrs) { int i; struct scatterlist *sg; @@ -175,7 +175,7 @@ int dma_direct_supported(struct device *dev, u64 mask) return 1; } -static int dma_direct_mapping_error(struct device *dev, dma_addr_t dma_addr) +int dma_direct_mapping_error(struct device *dev, dma_addr_t dma_addr) { return dma_addr == DIRECT_MAPPING_ERROR; } diff --git a/lib/dma-noncoherent.c b/lib/dma-noncoherent.c new file mode 100644 index 000000000000..79e9a757387f --- /dev/null +++ b/lib/dma-noncoherent.c @@ -0,0 +1,102 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2018 Christoph Hellwig. + * + * DMA operations that map physical memory directly without providing cache + * coherence. + */ +#include <linux/export.h> +#include <linux/mm.h> +#include <linux/dma-direct.h> +#include <linux/dma-noncoherent.h> +#include <linux/scatterlist.h> + +static void dma_noncoherent_sync_single_for_device(struct device *dev, + dma_addr_t addr, size_t size, enum dma_data_direction dir) +{ + arch_sync_dma_for_device(dev, dma_to_phys(dev, addr), size, dir); +} + +static void dma_noncoherent_sync_sg_for_device(struct device *dev, + struct scatterlist *sgl, int nents, enum dma_data_direction dir) +{ + struct scatterlist *sg; + int i; + + for_each_sg(sgl, sg, nents, i) + arch_sync_dma_for_device(dev, sg_phys(sg), sg->length, dir); +} + +static dma_addr_t dma_noncoherent_map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, enum dma_data_direction dir, + unsigned long attrs) +{ + dma_addr_t addr; + + addr = dma_direct_map_page(dev, page, offset, size, dir, attrs); + if (!dma_mapping_error(dev, addr) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + arch_sync_dma_for_device(dev, page_to_phys(page) + offset, + size, dir); + return addr; +} + +static int dma_noncoherent_map_sg(struct device *dev, struct scatterlist *sgl, + int nents, enum dma_data_direction dir, unsigned long attrs) +{ + nents = dma_direct_map_sg(dev, sgl, nents, dir, attrs); + if (nents > 0 && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + dma_noncoherent_sync_sg_for_device(dev, sgl, nents, dir); + return nents; +} + +#ifdef CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU +static void dma_noncoherent_sync_single_for_cpu(struct device *dev, + dma_addr_t addr, size_t size, enum dma_data_direction dir) +{ + arch_sync_dma_for_cpu(dev, dma_to_phys(dev, addr), size, dir); +} + +static void dma_noncoherent_sync_sg_for_cpu(struct device *dev, + struct scatterlist *sgl, int nents, enum dma_data_direction dir) +{ + struct scatterlist *sg; + int i; + + for_each_sg(sgl, sg, nents, i) + arch_sync_dma_for_cpu(dev, sg_phys(sg), sg->length, dir); +} + +static void dma_noncoherent_unmap_page(struct device *dev, dma_addr_t addr, + size_t size, enum dma_data_direction dir, unsigned long attrs) +{ + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + dma_noncoherent_sync_single_for_cpu(dev, addr, size, dir); +} + +static void dma_noncoherent_unmap_sg(struct device *dev, struct scatterlist *sgl, + int nents, enum dma_data_direction dir, unsigned long attrs) +{ + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + dma_noncoherent_sync_sg_for_cpu(dev, sgl, nents, dir); +} +#endif + +const struct dma_map_ops dma_noncoherent_ops = { + .alloc = arch_dma_alloc, + .free = arch_dma_free, + .mmap = arch_dma_mmap, + .sync_single_for_device = dma_noncoherent_sync_single_for_device, + .sync_sg_for_device = dma_noncoherent_sync_sg_for_device, + .map_page = dma_noncoherent_map_page, + .map_sg = dma_noncoherent_map_sg, +#ifdef CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU + .sync_single_for_cpu = dma_noncoherent_sync_single_for_cpu, + .sync_sg_for_cpu = dma_noncoherent_sync_sg_for_cpu, + .unmap_page = dma_noncoherent_unmap_page, + .unmap_sg = dma_noncoherent_unmap_sg, +#endif + .dma_supported = dma_direct_supported, + .mapping_error = dma_direct_mapping_error, + .cache_sync = arch_dma_cache_sync, +}; +EXPORT_SYMBOL(dma_noncoherent_ops); -- 2.17.0
