1 /* SPDX-License-Identifier: GPL-2.0 */
3 * Copyright (C) 2004 IBM
5 * Implements the generic device dma API for powerpc.
6 * the pci and vio busses
8 #ifndef _ASM_DMA_MAPPING_H
9 #define _ASM_DMA_MAPPING_H
12 #include <linux/types.h>
13 #include <linux/cache.h>
14 /* need struct page definitions */
16 #include <linux/scatterlist.h>
17 #include <linux/dma-debug.h>
19 #include <asm/swiotlb.h>
21 /* Some dma direct funcs must be visible for use in other dma_ops */
22 extern void *__dma_nommu_alloc_coherent(struct device *dev, size_t size,
23 dma_addr_t *dma_handle, gfp_t flag,
25 extern void __dma_nommu_free_coherent(struct device *dev, size_t size,
26 void *vaddr, dma_addr_t dma_handle,
28 int dma_nommu_map_sg(struct device *dev, struct scatterlist *sgl,
29 int nents, enum dma_data_direction direction,
31 dma_addr_t dma_nommu_map_page(struct device *dev, struct page *page,
32 unsigned long offset, size_t size,
33 enum dma_data_direction dir, unsigned long attrs);
35 #ifdef CONFIG_NOT_COHERENT_CACHE
37 * DMA-consistent mapping functions for PowerPCs that don't support
38 * cache snooping. These allocate/free a region of uncached mapped
39 * memory space for use with DMA devices. Alternatively, you could
40 * allocate the space "normally" and use the cache management functions
41 * to ensure it is consistent.
44 extern void __dma_sync(void *vaddr, size_t size, int direction);
45 extern void __dma_sync_page(struct page *page, unsigned long offset,
46 size_t size, int direction);
47 extern unsigned long __dma_get_coherent_pfn(unsigned long cpu_addr);
49 #else /* ! CONFIG_NOT_COHERENT_CACHE */
51 * Cache coherent cores.
54 #define __dma_sync(addr, size, rw) ((void)0)
55 #define __dma_sync_page(pg, off, sz, rw) ((void)0)
57 #endif /* ! CONFIG_NOT_COHERENT_CACHE */
59 static inline unsigned long device_to_mask(struct device *dev)
61 if (dev->dma_mask && *dev->dma_mask)
62 return *dev->dma_mask;
63 /* Assume devices without mask can take 32 bit addresses */
68 * Available generic sets of operations
71 extern const struct dma_map_ops dma_iommu_ops;
73 extern const struct dma_map_ops dma_nommu_ops;
75 static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
77 /* We don't handle the NULL dev case for ISA for now. We could
78 * do it via an out of line call but it is not needed for now. The
79 * only ISA DMA device we support is the floppy and we have a hack
80 * in the floppy driver directly to get a device for us.
88 * Get the dma offset on configurations where the dma address can be determined
89 * from the physical address by looking at a simple offset. Direct dma and
90 * swiotlb use this function, but it is typically not used by implementations
93 static inline dma_addr_t get_dma_offset(struct device *dev)
96 return dev->archdata.dma_offset;
98 return PCI_DRAM_OFFSET;
101 static inline void set_dma_offset(struct device *dev, dma_addr_t off)
104 dev->archdata.dma_offset = off;
107 #endif /* __KERNEL__ */
108 #endif /* _ASM_DMA_MAPPING_H */