1 /*
2 * DMA region bookkeeping routines
3 *
4 * Copyright (C) 2002 Maas Digital LLC
5 *
6 * This code is licensed under the GPL. See the file COPYING in the root
7 * directory of the kernel sources for details.
8 */
9
10 #ifndef IEEE1394_DMA_H
11 #define IEEE1394_DMA_H
12
13 #include <linux/pci.h>
14 #include <asm/scatterlist.h>
15
16 /* struct dma_prog_region
17
18 a small, physically-contiguous DMA buffer with random-access,
19 synchronous usage characteristics
20 */
21
22 struct dma_prog_region {
23 unsigned char *kvirt; /* kernel virtual address */
24 struct pci_dev *dev; /* PCI device */
25 unsigned int n_pages; /* # of kernel pages */
26 dma_addr_t bus_addr; /* base bus address */
27 };
28
29 /* clear out all fields but do not allocate any memory */
30 void dma_prog_region_init(struct dma_prog_region *prog);
31 int dma_prog_region_alloc(struct dma_prog_region *prog, unsigned long n_bytes, struct pci_dev *dev);
32 void dma_prog_region_free(struct dma_prog_region *prog);
33
dma_prog_region_offset_to_bus(struct dma_prog_region * prog,unsigned long offset)34 static inline dma_addr_t dma_prog_region_offset_to_bus(struct dma_prog_region *prog, unsigned long offset)
35 {
36 return prog->bus_addr + offset;
37 }
38
39 /* struct dma_region
40
41 a large, non-physically-contiguous DMA buffer with streaming,
42 asynchronous usage characteristics
43 */
44
45 struct dma_region {
46 unsigned char *kvirt; /* kernel virtual address */
47 struct pci_dev *dev; /* PCI device */
48 unsigned int n_pages; /* # of kernel pages */
49 unsigned int n_dma_pages; /* # of IOMMU pages */
50 struct scatterlist *sglist; /* IOMMU mapping */
51 int direction; /* PCI_DMA_TODEVICE, etc */
52 };
53
54 /* clear out all fields but do not allocate anything */
55 void dma_region_init(struct dma_region *dma);
56
57 /* allocate the buffer and map it to the IOMMU */
58 int dma_region_alloc(struct dma_region *dma, unsigned long n_bytes, struct pci_dev *dev, int direction);
59
60 /* unmap and free the buffer */
61 void dma_region_free(struct dma_region *dma);
62
63 /* sync the IO bus' view of the buffer with the CPU's view */
64 void dma_region_sync(struct dma_region *dma, unsigned long offset, unsigned long len);
65
66 /* map the buffer into a user space process */
67 int dma_region_mmap(struct dma_region *dma, struct file *file, struct vm_area_struct *vma);
68
69 /* macro to index into a DMA region (or dma_prog_region) */
70 #define dma_region_i(_dma, _type, _index) ( ((_type*) ((_dma)->kvirt)) + (_index) )
71
72 /* return the DMA bus address of the byte with the given offset
73 relative to the beginning of the dma_region */
74 dma_addr_t dma_region_offset_to_bus(struct dma_region *dma, unsigned long offset);
75
76 /* round up a number of bytes to be a multiple of the PAGE_SIZE */
round_up_to_page(unsigned long len)77 static inline unsigned long round_up_to_page(unsigned long len)
78 {
79 if (len % PAGE_SIZE)
80 len += PAGE_SIZE - (len % PAGE_SIZE);
81 return len;
82 }
83
84 #endif /* IEEE1394_DMA_H */
85