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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> |
b920de1b DH |
18 | #include <asm/io.h> |
19 | ||
012c79ba DH |
20 | static unsigned long pci_sram_allocated = 0xbc000000; |
21 | ||
b920de1b DH |
22 | void *dma_alloc_coherent(struct device *dev, size_t size, |
23 | dma_addr_t *dma_handle, int gfp) | |
24 | { | |
25 | unsigned long addr; | |
26 | void *ret; | |
27 | ||
6e0c64f4 JL |
28 | pr_debug("dma_alloc_coherent(%s,%zu,%x)\n", |
29 | dev ? dev_name(dev) : "?", size, gfp); | |
012c79ba DH |
30 | |
31 | if (0xbe000000 - pci_sram_allocated >= size) { | |
32 | size = (size + 255) & ~255; | |
33 | addr = pci_sram_allocated; | |
34 | pci_sram_allocated += size; | |
35 | ret = (void *) addr; | |
36 | goto done; | |
37 | } | |
38 | ||
b920de1b DH |
39 | /* ignore region specifiers */ |
40 | gfp &= ~(__GFP_DMA | __GFP_HIGHMEM); | |
41 | ||
42 | if (dev == NULL || dev->coherent_dma_mask < 0xffffffff) | |
43 | gfp |= GFP_DMA; | |
44 | ||
45 | addr = __get_free_pages(gfp, get_order(size)); | |
46 | if (!addr) | |
47 | return NULL; | |
48 | ||
49 | /* map the coherent memory through the uncached memory window */ | |
50 | ret = (void *) (addr | 0x20000000); | |
51 | ||
52 | /* fill the memory with obvious rubbish */ | |
53 | memset((void *) addr, 0xfb, size); | |
54 | ||
55 | /* write back and evict all cache lines covering this region */ | |
56 | mn10300_dcache_flush_inv_range2(virt_to_phys((void *) addr), PAGE_SIZE); | |
57 | ||
012c79ba | 58 | done: |
b920de1b | 59 | *dma_handle = virt_to_bus((void *) addr); |
012c79ba | 60 | printk("dma_alloc_coherent() = %p [%x]\n", ret, *dma_handle); |
b920de1b DH |
61 | return ret; |
62 | } | |
63 | EXPORT_SYMBOL(dma_alloc_coherent); | |
64 | ||
65 | void dma_free_coherent(struct device *dev, size_t size, void *vaddr, | |
66 | dma_addr_t dma_handle) | |
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 | } | |
75 | EXPORT_SYMBOL(dma_free_coherent); |