Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* pci-dma-nommu.c: Dynamic DMA mapping support for the FRV |
| 2 | * |
| 3 | * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. |
David Woodhouse | 44d1b98 | 2008-06-05 22:46:18 -0700 | [diff] [blame] | 4 | * Written by David Woodhouse (dwmw2@infradead.org) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public License |
| 8 | * as published by the Free Software Foundation; either version |
| 9 | * 2 of the License, or (at your option) any later version. |
| 10 | */ |
| 11 | |
| 12 | #include <linux/types.h> |
| 13 | #include <linux/slab.h> |
| 14 | #include <linux/dma-mapping.h> |
| 15 | #include <linux/list.h> |
| 16 | #include <linux/pci.h> |
| 17 | #include <asm/io.h> |
| 18 | |
| 19 | #if 1 |
| 20 | #define DMA_SRAM_START dma_coherent_mem_start |
| 21 | #define DMA_SRAM_END dma_coherent_mem_end |
| 22 | #else // Use video RAM on Matrox |
| 23 | #define DMA_SRAM_START 0xe8900000 |
| 24 | #define DMA_SRAM_END 0xe8a00000 |
| 25 | #endif |
| 26 | |
| 27 | struct dma_alloc_record { |
| 28 | struct list_head list; |
| 29 | unsigned long ofs; |
| 30 | unsigned long len; |
| 31 | }; |
| 32 | |
| 33 | static DEFINE_SPINLOCK(dma_alloc_lock); |
| 34 | static LIST_HEAD(dma_alloc_list); |
| 35 | |
Al Viro | a5da7d3 | 2005-10-21 03:21:18 -0400 | [diff] [blame] | 36 | void *dma_alloc_coherent(struct device *hwdev, size_t size, dma_addr_t *dma_handle, gfp_t gfp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | { |
| 38 | struct dma_alloc_record *new; |
| 39 | struct list_head *this = &dma_alloc_list; |
| 40 | unsigned long flags; |
| 41 | unsigned long start = DMA_SRAM_START; |
| 42 | unsigned long end; |
| 43 | |
| 44 | if (!DMA_SRAM_START) { |
| 45 | printk("%s called without any DMA area reserved!\n", __func__); |
| 46 | return NULL; |
| 47 | } |
| 48 | |
| 49 | new = kmalloc(sizeof (*new), GFP_ATOMIC); |
| 50 | if (!new) |
| 51 | return NULL; |
| 52 | |
| 53 | /* Round up to a reasonable alignment */ |
| 54 | new->len = (size + 31) & ~31; |
| 55 | |
| 56 | spin_lock_irqsave(&dma_alloc_lock, flags); |
| 57 | |
| 58 | list_for_each (this, &dma_alloc_list) { |
| 59 | struct dma_alloc_record *this_r = list_entry(this, struct dma_alloc_record, list); |
| 60 | end = this_r->ofs; |
| 61 | |
| 62 | if (end - start >= size) |
| 63 | goto gotone; |
| 64 | |
| 65 | start = this_r->ofs + this_r->len; |
| 66 | } |
| 67 | /* Reached end of list. */ |
| 68 | end = DMA_SRAM_END; |
| 69 | this = &dma_alloc_list; |
| 70 | |
| 71 | if (end - start >= size) { |
| 72 | gotone: |
| 73 | new->ofs = start; |
| 74 | list_add_tail(&new->list, this); |
| 75 | spin_unlock_irqrestore(&dma_alloc_lock, flags); |
| 76 | |
| 77 | *dma_handle = start; |
| 78 | return (void *)start; |
| 79 | } |
| 80 | |
| 81 | kfree(new); |
| 82 | spin_unlock_irqrestore(&dma_alloc_lock, flags); |
| 83 | return NULL; |
| 84 | } |
| 85 | |
David Howells | 4023440 | 2006-01-08 01:01:19 -0800 | [diff] [blame] | 86 | EXPORT_SYMBOL(dma_alloc_coherent); |
| 87 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | void dma_free_coherent(struct device *hwdev, size_t size, void *vaddr, dma_addr_t dma_handle) |
| 89 | { |
| 90 | struct dma_alloc_record *rec; |
| 91 | unsigned long flags; |
| 92 | |
| 93 | spin_lock_irqsave(&dma_alloc_lock, flags); |
| 94 | |
| 95 | list_for_each_entry(rec, &dma_alloc_list, list) { |
| 96 | if (rec->ofs == dma_handle) { |
| 97 | list_del(&rec->list); |
| 98 | kfree(rec); |
| 99 | spin_unlock_irqrestore(&dma_alloc_lock, flags); |
| 100 | return; |
| 101 | } |
| 102 | } |
| 103 | spin_unlock_irqrestore(&dma_alloc_lock, flags); |
| 104 | BUG(); |
| 105 | } |
| 106 | |
David Howells | 4023440 | 2006-01-08 01:01:19 -0800 | [diff] [blame] | 107 | EXPORT_SYMBOL(dma_free_coherent); |
| 108 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | /* |
| 110 | * Map a single buffer of the indicated size for DMA in streaming mode. |
| 111 | * The 32-bit bus address to use is returned. |
| 112 | * |
| 113 | * Once the device is given the dma address, the device owns this memory |
David Howells | c9af956 | 2008-10-15 16:50:53 +0100 | [diff] [blame] | 114 | * until either dma_unmap_single or pci_dma_sync_single is performed. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 115 | */ |
| 116 | dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size, |
| 117 | enum dma_data_direction direction) |
| 118 | { |
| 119 | if (direction == DMA_NONE) |
| 120 | BUG(); |
| 121 | |
| 122 | frv_cache_wback_inv((unsigned long) ptr, (unsigned long) ptr + size); |
| 123 | |
| 124 | return virt_to_bus(ptr); |
| 125 | } |
| 126 | |
David Howells | 4023440 | 2006-01-08 01:01:19 -0800 | [diff] [blame] | 127 | EXPORT_SYMBOL(dma_map_single); |
| 128 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | /* |
| 130 | * Map a set of buffers described by scatterlist in streaming |
| 131 | * mode for DMA. This is the scather-gather version of the |
David Howells | c9af956 | 2008-10-15 16:50:53 +0100 | [diff] [blame] | 132 | * above dma_map_single interface. Here the scatter gather list |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | * elements are each tagged with the appropriate dma address |
| 134 | * and length. They are obtained via sg_dma_{address,length}(SG). |
| 135 | * |
| 136 | * NOTE: An implementation may be able to use a smaller number of |
| 137 | * DMA address/length pairs than there are SG table elements. |
| 138 | * (for example via virtual mapping capabilities) |
| 139 | * The routine returns the number of addr/length pairs actually |
| 140 | * used, at most nents. |
| 141 | * |
David Howells | c9af956 | 2008-10-15 16:50:53 +0100 | [diff] [blame] | 142 | * Device ownership issues as mentioned above for dma_map_single are |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | * the same here. |
| 144 | */ |
| 145 | int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents, |
| 146 | enum dma_data_direction direction) |
| 147 | { |
| 148 | int i; |
| 149 | |
| 150 | for (i=0; i<nents; i++) |
| 151 | frv_cache_wback_inv(sg_dma_address(&sg[i]), |
| 152 | sg_dma_address(&sg[i]) + sg_dma_len(&sg[i])); |
| 153 | |
| 154 | if (direction == DMA_NONE) |
| 155 | BUG(); |
| 156 | |
| 157 | return nents; |
| 158 | } |
David Howells | 4023440 | 2006-01-08 01:01:19 -0800 | [diff] [blame] | 159 | |
| 160 | EXPORT_SYMBOL(dma_map_sg); |
David Howells | c9af956 | 2008-10-15 16:50:53 +0100 | [diff] [blame] | 161 | |
| 162 | /* |
| 163 | * Map a single page of the indicated size for DMA in streaming mode. |
| 164 | * The 32-bit bus address to use is returned. |
| 165 | * |
| 166 | * Device ownership issues as mentioned above for dma_map_single are |
| 167 | * the same here. |
| 168 | */ |
| 169 | dma_addr_t dma_map_page(struct device *dev, struct page *page, unsigned long offset, |
| 170 | size_t size, enum dma_data_direction direction) |
| 171 | { |
| 172 | BUG_ON(direction == DMA_NONE); |
| 173 | flush_dcache_page(page); |
| 174 | return (dma_addr_t) page_to_phys(page) + offset; |
| 175 | } |
| 176 | |
| 177 | EXPORT_SYMBOL(dma_map_page); |