From 849369d6c66d3054688672f97d31fceb8e8230fb Mon Sep 17 00:00:00 2001 From: root Date: Fri, 25 Dec 2015 04:40:36 +0000 Subject: initial_commit --- arch/powerpc/kernel/dma.c | 199 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 199 insertions(+) create mode 100644 arch/powerpc/kernel/dma.c (limited to 'arch/powerpc/kernel/dma.c') diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c new file mode 100644 index 00000000..d238c082 --- /dev/null +++ b/arch/powerpc/kernel/dma.c @@ -0,0 +1,199 @@ +/* + * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corporation + * + * Provide default implementations of the DMA mapping callbacks for + * directly mapped busses. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * Generic direct DMA implementation + * + * This implementation supports a per-device offset that can be applied if + * the address at which memory is visible to devices is not 0. Platform code + * can set archdata.dma_data to an unsigned long holding the offset. By + * default the offset is PCI_DRAM_OFFSET. + */ + + +void *dma_direct_alloc_coherent(struct device *dev, size_t size, + dma_addr_t *dma_handle, gfp_t flag) +{ + void *ret; +#ifdef CONFIG_NOT_COHERENT_CACHE + ret = __dma_alloc_coherent(dev, size, dma_handle, flag); + if (ret == NULL) + return NULL; + *dma_handle += get_dma_offset(dev); + return ret; +#else + struct page *page; + int node = dev_to_node(dev); + + /* ignore region specifiers */ + flag &= ~(__GFP_HIGHMEM); + + page = alloc_pages_node(node, flag, get_order(size)); + if (page == NULL) + return NULL; + ret = page_address(page); + memset(ret, 0, size); + *dma_handle = virt_to_abs(ret) + get_dma_offset(dev); + + return ret; +#endif +} + +void dma_direct_free_coherent(struct device *dev, size_t size, + void *vaddr, dma_addr_t dma_handle) +{ +#ifdef CONFIG_NOT_COHERENT_CACHE + __dma_free_coherent(size, vaddr); +#else + free_pages((unsigned long)vaddr, get_order(size)); +#endif +} + +static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, + int nents, enum dma_data_direction direction, + struct dma_attrs *attrs) +{ + struct scatterlist *sg; + int i; + + for_each_sg(sgl, sg, nents, i) { + sg->dma_address = sg_phys(sg) + get_dma_offset(dev); + sg->dma_length = sg->length; + __dma_sync_page(sg_page(sg), sg->offset, sg->length, direction); + } + + return nents; +} + +static void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sg, + int nents, enum dma_data_direction direction, + struct dma_attrs *attrs) +{ +} + +static int dma_direct_dma_supported(struct device *dev, u64 mask) +{ +#ifdef CONFIG_PPC64 + /* Could be improved so platforms can set the limit in case + * they have limited DMA windows + */ + return mask >= get_dma_offset(dev) + (memblock_end_of_DRAM() - 1); +#else + return 1; +#endif +} + +static inline dma_addr_t dma_direct_map_page(struct device *dev, + struct page *page, + unsigned long offset, + size_t size, + enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + BUG_ON(dir == DMA_NONE); + __dma_sync_page(page, offset, size, dir); + return page_to_phys(page) + offset + get_dma_offset(dev); +} + +static inline void dma_direct_unmap_page(struct device *dev, + dma_addr_t dma_address, + size_t size, + enum dma_data_direction direction, + struct dma_attrs *attrs) +{ +} + +#ifdef CONFIG_NOT_COHERENT_CACHE +static inline void dma_direct_sync_sg(struct device *dev, + struct scatterlist *sgl, int nents, + enum dma_data_direction direction) +{ + struct scatterlist *sg; + int i; + + for_each_sg(sgl, sg, nents, i) + __dma_sync_page(sg_page(sg), sg->offset, sg->length, direction); +} + +static inline void dma_direct_sync_single(struct device *dev, + dma_addr_t dma_handle, size_t size, + enum dma_data_direction direction) +{ + __dma_sync(bus_to_virt(dma_handle), size, direction); +} +#endif + +struct dma_map_ops dma_direct_ops = { + .alloc_coherent = dma_direct_alloc_coherent, + .free_coherent = dma_direct_free_coherent, + .map_sg = dma_direct_map_sg, + .unmap_sg = dma_direct_unmap_sg, + .dma_supported = dma_direct_dma_supported, + .map_page = dma_direct_map_page, + .unmap_page = dma_direct_unmap_page, +#ifdef CONFIG_NOT_COHERENT_CACHE + .sync_single_for_cpu = dma_direct_sync_single, + .sync_single_for_device = dma_direct_sync_single, + .sync_sg_for_cpu = dma_direct_sync_sg, + .sync_sg_for_device = dma_direct_sync_sg, +#endif +}; +EXPORT_SYMBOL(dma_direct_ops); + +#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16) + +int dma_set_mask(struct device *dev, u64 dma_mask) +{ + struct dma_map_ops *dma_ops = get_dma_ops(dev); + + if (ppc_md.dma_set_mask) + return ppc_md.dma_set_mask(dev, dma_mask); + if (unlikely(dma_ops == NULL)) + return -EIO; + if (dma_ops->set_dma_mask != NULL) + return dma_ops->set_dma_mask(dev, dma_mask); + if (!dev->dma_mask || !dma_supported(dev, dma_mask)) + return -EIO; + *dev->dma_mask = dma_mask; + return 0; +} +EXPORT_SYMBOL(dma_set_mask); + +static int __init dma_init(void) +{ + dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES); + + return 0; +} +fs_initcall(dma_init); + +int dma_mmap_coherent(struct device *dev, struct vm_area_struct *vma, + void *cpu_addr, dma_addr_t handle, size_t size) +{ + unsigned long pfn; + +#ifdef CONFIG_NOT_COHERENT_CACHE + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); + pfn = __dma_get_coherent_pfn((unsigned long)cpu_addr); +#else + pfn = page_to_pfn(virt_to_page(cpu_addr)); +#endif + return remap_pfn_range(vma, vma->vm_start, + pfn + vma->vm_pgoff, + vma->vm_end - vma->vm_start, + vma->vm_page_prot); +} +EXPORT_SYMBOL_GPL(dma_mmap_coherent); -- cgit v1.2.3