tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (C) 2004 IBM
4 *
5 * Implements the generic device dma API for powerpc.
6 * the pci and vio busses
7 */
8#ifndef _ASM_DMA_MAPPING_H
9#define _ASM_DMA_MAPPING_H
10#ifdef __KERNEL__
11
12#include <linux/types.h>
13#include <linux/cache.h>
14/* need struct page definitions */
15#include <linux/mm.h>
16#include <linux/scatterlist.h>
17#include <linux/dma-debug.h>
18#include <asm/io.h>
19#include <asm/swiotlb.h>
20
21/* Some dma direct funcs must be visible for use in other dma_ops */
22extern void *__dma_nommu_alloc_coherent(struct device *dev, size_t size,
23 dma_addr_t *dma_handle, gfp_t flag,
24 unsigned long attrs);
25extern void __dma_nommu_free_coherent(struct device *dev, size_t size,
26 void *vaddr, dma_addr_t dma_handle,
27 unsigned long attrs);
28extern int dma_nommu_mmap_coherent(struct device *dev,
29 struct vm_area_struct *vma,
30 void *cpu_addr, dma_addr_t handle,
31 size_t size, unsigned long attrs);
32
33#ifdef CONFIG_NOT_COHERENT_CACHE
34/*
35 * DMA-consistent mapping functions for PowerPCs that don't support
36 * cache snooping. These allocate/free a region of uncached mapped
37 * memory space for use with DMA devices. Alternatively, you could
38 * allocate the space "normally" and use the cache management functions
39 * to ensure it is consistent.
40 */
41struct device;
42extern void *__dma_alloc_coherent(struct device *dev, size_t size,
43 dma_addr_t *handle, gfp_t gfp);
44extern void __dma_free_coherent(size_t size, void *vaddr);
45extern void __dma_sync(void *vaddr, size_t size, int direction);
46extern void __dma_sync_page(struct page *page, unsigned long offset,
47 size_t size, int direction);
48extern unsigned long __dma_get_coherent_pfn(unsigned long cpu_addr);
49
50#else /* ! CONFIG_NOT_COHERENT_CACHE */
51/*
52 * Cache coherent cores.
53 */
54
55#define __dma_alloc_coherent(dev, gfp, size, handle) NULL
56#define __dma_free_coherent(size, addr) ((void)0)
57#define __dma_sync(addr, size, rw) ((void)0)
58#define __dma_sync_page(pg, off, sz, rw) ((void)0)
59
60#endif /* ! CONFIG_NOT_COHERENT_CACHE */
61
62static inline unsigned long device_to_mask(struct device *dev)
63{
64 if (dev->dma_mask && *dev->dma_mask)
65 return *dev->dma_mask;
66 /* Assume devices without mask can take 32 bit addresses */
67 return 0xfffffffful;
68}
69
70/*
71 * Available generic sets of operations
72 */
73#ifdef CONFIG_PPC64
74extern struct dma_map_ops dma_iommu_ops;
75#endif
76extern const struct dma_map_ops dma_nommu_ops;
77
78static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
79{
80 /* We don't handle the NULL dev case for ISA for now. We could
81 * do it via an out of line call but it is not needed for now. The
82 * only ISA DMA device we support is the floppy and we have a hack
83 * in the floppy driver directly to get a device for us.
84 */
85 return NULL;
86}
87
88/*
89 * get_dma_offset()
90 *
91 * Get the dma offset on configurations where the dma address can be determined
92 * from the physical address by looking at a simple offset. Direct dma and
93 * swiotlb use this function, but it is typically not used by implementations
94 * with an iommu.
95 */
96static inline dma_addr_t get_dma_offset(struct device *dev)
97{
98 if (dev)
99 return dev->archdata.dma_offset;
100
101 return PCI_DRAM_OFFSET;
102}
103
104static inline void set_dma_offset(struct device *dev, dma_addr_t off)
105{
106 if (dev)
107 dev->archdata.dma_offset = off;
108}
109
110#define HAVE_ARCH_DMA_SET_MASK 1
111extern int dma_set_mask(struct device *dev, u64 dma_mask);
112
113extern u64 __dma_get_required_mask(struct device *dev);
114
115#define ARCH_HAS_DMA_MMAP_COHERENT
116
117#endif /* __KERNEL__ */
118#endif /* _ASM_DMA_MAPPING_H */