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b920de1b DH |
1 | /* MN10300 Dynamic DMA mapping support |
2 | * | |
3 | * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. | |
4 | * Written by David Howells (dhowells@redhat.com) | |
5 | * Derived from: arch/i386/kernel/pci-dma.c | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public Licence | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the Licence, or (at your option) any later version. | |
11 | */ | |
12 | ||
13 | #include <linux/types.h> | |
14 | #include <linux/mm.h> | |
15 | #include <linux/string.h> | |
16 | #include <linux/pci.h> | |
5a0e3ad6 | 17 | #include <linux/gfp.h> |
77cb621c | 18 | #include <linux/export.h> |
b920de1b DH |
19 | #include <asm/io.h> |
20 | ||
012c79ba DH |
21 | static unsigned long pci_sram_allocated = 0xbc000000; |
22 | ||
f151341c | 23 | static void *mn10300_dma_alloc(struct device *dev, size_t size, |
00085f1e | 24 | dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs) |
b920de1b DH |
25 | { |
26 | unsigned long addr; | |
27 | void *ret; | |
28 | ||
6e0c64f4 JL |
29 | pr_debug("dma_alloc_coherent(%s,%zu,%x)\n", |
30 | dev ? dev_name(dev) : "?", size, gfp); | |
012c79ba DH |
31 | |
32 | if (0xbe000000 - pci_sram_allocated >= size) { | |
33 | size = (size + 255) & ~255; | |
34 | addr = pci_sram_allocated; | |
35 | pci_sram_allocated += size; | |
36 | ret = (void *) addr; | |
37 | goto done; | |
38 | } | |
39 | ||
b920de1b DH |
40 | /* ignore region specifiers */ |
41 | gfp &= ~(__GFP_DMA | __GFP_HIGHMEM); | |
42 | ||
43 | if (dev == NULL || dev->coherent_dma_mask < 0xffffffff) | |
44 | gfp |= GFP_DMA; | |
45 | ||
46 | addr = __get_free_pages(gfp, get_order(size)); | |
47 | if (!addr) | |
48 | return NULL; | |
49 | ||
50 | /* map the coherent memory through the uncached memory window */ | |
51 | ret = (void *) (addr | 0x20000000); | |
52 | ||
53 | /* fill the memory with obvious rubbish */ | |
54 | memset((void *) addr, 0xfb, size); | |
55 | ||
56 | /* write back and evict all cache lines covering this region */ | |
57 | mn10300_dcache_flush_inv_range2(virt_to_phys((void *) addr), PAGE_SIZE); | |
58 | ||
012c79ba | 59 | done: |
b920de1b | 60 | *dma_handle = virt_to_bus((void *) addr); |
012c79ba | 61 | printk("dma_alloc_coherent() = %p [%x]\n", ret, *dma_handle); |
b920de1b DH |
62 | return ret; |
63 | } | |
b920de1b | 64 | |
f151341c | 65 | static void mn10300_dma_free(struct device *dev, size_t size, void *vaddr, |
00085f1e | 66 | dma_addr_t dma_handle, unsigned long attrs) |
b920de1b DH |
67 | { |
68 | unsigned long addr = (unsigned long) vaddr & ~0x20000000; | |
69 | ||
012c79ba DH |
70 | if (addr >= 0x9c000000) |
71 | return; | |
72 | ||
b920de1b DH |
73 | free_pages(addr, get_order(size)); |
74 | } | |
f151341c CH |
75 | |
76 | static int mn10300_dma_map_sg(struct device *dev, struct scatterlist *sglist, | |
77 | int nents, enum dma_data_direction direction, | |
00085f1e | 78 | unsigned long attrs) |
f151341c CH |
79 | { |
80 | struct scatterlist *sg; | |
81 | int i; | |
82 | ||
83 | for_each_sg(sglist, sg, nents, i) { | |
84 | BUG_ON(!sg_page(sg)); | |
85 | ||
86 | sg->dma_address = sg_phys(sg); | |
87 | } | |
88 | ||
89 | mn10300_dcache_flush_inv(); | |
90 | return nents; | |
91 | } | |
92 | ||
93 | static dma_addr_t mn10300_dma_map_page(struct device *dev, struct page *page, | |
94 | unsigned long offset, size_t size, | |
00085f1e | 95 | enum dma_data_direction direction, unsigned long attrs) |
f151341c CH |
96 | { |
97 | return page_to_bus(page) + offset; | |
98 | } | |
99 | ||
100 | static void mn10300_dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle, | |
101 | size_t size, enum dma_data_direction direction) | |
102 | { | |
103 | mn10300_dcache_flush_inv(); | |
104 | } | |
105 | ||
106 | static void mn10300_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, | |
107 | int nelems, enum dma_data_direction direction) | |
108 | { | |
109 | mn10300_dcache_flush_inv(); | |
110 | } | |
111 | ||
112 | static int mn10300_dma_supported(struct device *dev, u64 mask) | |
113 | { | |
114 | /* | |
115 | * we fall back to GFP_DMA when the mask isn't all 1s, so we can't | |
116 | * guarantee allocations that must be within a tighter range than | |
117 | * GFP_DMA | |
118 | */ | |
119 | if (mask < 0x00ffffff) | |
120 | return 0; | |
121 | return 1; | |
122 | } | |
123 | ||
124 | struct dma_map_ops mn10300_dma_ops = { | |
125 | .alloc = mn10300_dma_alloc, | |
126 | .free = mn10300_dma_free, | |
127 | .map_page = mn10300_dma_map_page, | |
128 | .map_sg = mn10300_dma_map_sg, | |
129 | .sync_single_for_device = mn10300_dma_sync_single_for_device, | |
130 | .sync_sg_for_device = mn10300_dma_sync_sg_for_device, | |
131 | }; |