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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Support for DMA from PCI devices to main memory on | |
3 | * machines without an iommu or with directly addressable | |
4 | * RAM (typically a pmac with 2Gb of RAM or less) | |
5 | * | |
6 | * Copyright (C) 2003 Benjamin Herrenschmidt (benh@kernel.crashing.org) | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU General Public License | |
10 | * as published by the Free Software Foundation; either version | |
11 | * 2 of the License, or (at your option) any later version. | |
12 | */ | |
13 | ||
14 | #include <linux/kernel.h> | |
15 | #include <linux/pci.h> | |
16 | #include <linux/delay.h> | |
17 | #include <linux/string.h> | |
18 | #include <linux/init.h> | |
19 | #include <linux/bootmem.h> | |
20 | #include <linux/mm.h> | |
21 | #include <linux/dma-mapping.h> | |
22 | ||
23 | #include <asm/sections.h> | |
24 | #include <asm/io.h> | |
25 | #include <asm/prom.h> | |
26 | #include <asm/pci-bridge.h> | |
27 | #include <asm/machdep.h> | |
28 | #include <asm/pmac_feature.h> | |
29 | #include <asm/abs_addr.h> | |
30 | ||
31 | #include "pci.h" | |
32 | ||
33 | static void *pci_direct_alloc_coherent(struct device *hwdev, size_t size, | |
dd0fc66f | 34 | dma_addr_t *dma_handle, gfp_t flag) |
1da177e4 LT |
35 | { |
36 | void *ret; | |
37 | ||
38 | ret = (void *)__get_free_pages(flag, get_order(size)); | |
39 | if (ret != NULL) { | |
40 | memset(ret, 0, size); | |
41 | *dma_handle = virt_to_abs(ret); | |
42 | } | |
43 | return ret; | |
44 | } | |
45 | ||
46 | static void pci_direct_free_coherent(struct device *hwdev, size_t size, | |
47 | void *vaddr, dma_addr_t dma_handle) | |
48 | { | |
49 | free_pages((unsigned long)vaddr, get_order(size)); | |
50 | } | |
51 | ||
52 | static dma_addr_t pci_direct_map_single(struct device *hwdev, void *ptr, | |
53 | size_t size, enum dma_data_direction direction) | |
54 | { | |
55 | return virt_to_abs(ptr); | |
56 | } | |
57 | ||
58 | static void pci_direct_unmap_single(struct device *hwdev, dma_addr_t dma_addr, | |
59 | size_t size, enum dma_data_direction direction) | |
60 | { | |
61 | } | |
62 | ||
63 | static int pci_direct_map_sg(struct device *hwdev, struct scatterlist *sg, | |
64 | int nents, enum dma_data_direction direction) | |
65 | { | |
66 | int i; | |
67 | ||
68 | for (i = 0; i < nents; i++, sg++) { | |
69 | sg->dma_address = page_to_phys(sg->page) + sg->offset; | |
70 | sg->dma_length = sg->length; | |
71 | } | |
72 | ||
73 | return nents; | |
74 | } | |
75 | ||
76 | static void pci_direct_unmap_sg(struct device *hwdev, struct scatterlist *sg, | |
77 | int nents, enum dma_data_direction direction) | |
78 | { | |
79 | } | |
80 | ||
81 | static int pci_direct_dma_supported(struct device *dev, u64 mask) | |
82 | { | |
83 | return mask < 0x100000000ull; | |
84 | } | |
85 | ||
86 | void __init pci_direct_iommu_init(void) | |
87 | { | |
88 | pci_dma_ops.alloc_coherent = pci_direct_alloc_coherent; | |
89 | pci_dma_ops.free_coherent = pci_direct_free_coherent; | |
90 | pci_dma_ops.map_single = pci_direct_map_single; | |
91 | pci_dma_ops.unmap_single = pci_direct_unmap_single; | |
92 | pci_dma_ops.map_sg = pci_direct_map_sg; | |
93 | pci_dma_ops.unmap_sg = pci_direct_unmap_sg; | |
94 | pci_dma_ops.dma_supported = pci_direct_dma_supported; | |
95 | } |