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ca36c36b DV |
1 | /* |
2 | * ioremap.c | |
3 | * | |
4 | * Support for mapping between dma_addr_t values a phys_addr_t values. | |
5 | * | |
6 | * Copyright (C) 2005-2009 Scientific-Atlanta, Inc. | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License as published by | |
10 | * the Free Software Foundation; either version 2 of the License, or | |
11 | * (at your option) any later version. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public License | |
19 | * along with this program; if not, write to the Free Software | |
20 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
21 | * | |
70342287 | 22 | * Author: David VomLehn <dvomlehn@cisco.com> |
ca36c36b | 23 | * |
70342287 | 24 | * Description: Defines the platform resources for the SA settop. |
ca36c36b DV |
25 | * |
26 | * NOTE: The bootloader allocates persistent memory at an address which is | |
27 | * 16 MiB below the end of the highest address in KSEG0. All fixed | |
28 | * address memory reservations must avoid this region. | |
29 | */ | |
30 | ||
31 | #include <linux/kernel.h> | |
32 | #include <linux/module.h> | |
33 | ||
34 | #include <asm/mach-powertv/ioremap.h> | |
35 | ||
36 | /* | |
37 | * Define the sizes of and masks for grains in physical and DMA space. The | |
38 | * values are the same but the types are not. | |
39 | */ | |
40 | #define IOR_PHYS_GRAIN ((phys_addr_t) 1 << IOR_LSBITS) | |
41 | #define IOR_PHYS_GRAIN_MASK (IOR_PHYS_GRAIN - 1) | |
42 | ||
43 | #define IOR_DMA_GRAIN ((dma_addr_t) 1 << IOR_LSBITS) | |
44 | #define IOR_DMA_GRAIN_MASK (IOR_DMA_GRAIN - 1) | |
45 | ||
46 | /* | |
47 | * Values that, when accessed by an index derived from a phys_addr_t and | |
48 | * added to phys_addr_t value, yield a DMA address | |
49 | */ | |
50 | struct ior_phys_to_dma _ior_phys_to_dma[IOR_NUM_PHYS_TO_DMA]; | |
51 | EXPORT_SYMBOL(_ior_phys_to_dma); | |
52 | ||
53 | /* | |
54 | * Values that, when accessed by an index derived from a dma_addr_t and | |
55 | * added to that dma_addr_t value, yield a physical address | |
56 | */ | |
57 | struct ior_dma_to_phys _ior_dma_to_phys[IOR_NUM_DMA_TO_PHYS]; | |
58 | EXPORT_SYMBOL(_ior_dma_to_phys); | |
59 | ||
60 | /** | |
61 | * setup_dma_to_phys - set up conversion from DMA to physical addresses | |
62 | * @dma_idx: Top IOR_LSBITS bits of the DMA address, i.e. an index | |
63 | * into the array _dma_to_phys. | |
64 | * @delta: Value that, when added to the DMA address, will yield the | |
65 | * physical address | |
66 | * @s: Number of bytes in the section of memory with the given delta | |
67 | * between DMA and physical addresses. | |
68 | */ | |
69 | static void setup_dma_to_phys(dma_addr_t dma, phys_addr_t delta, dma_addr_t s) | |
70 | { | |
71 | int dma_idx, first_idx, last_idx; | |
72 | phys_addr_t first, last; | |
73 | ||
74 | /* | |
75 | * Calculate the first and last indices, rounding the first up and | |
76 | * the second down. | |
77 | */ | |
78 | first = dma & ~IOR_DMA_GRAIN_MASK; | |
79 | last = (dma + s - 1) & ~IOR_DMA_GRAIN_MASK; | |
80 | first_idx = first >> IOR_LSBITS; /* Convert to indices */ | |
81 | last_idx = last >> IOR_LSBITS; | |
82 | ||
83 | for (dma_idx = first_idx; dma_idx <= last_idx; dma_idx++) | |
84 | _ior_dma_to_phys[dma_idx].offset = delta >> IOR_DMA_SHIFT; | |
85 | } | |
86 | ||
87 | /** | |
88 | * setup_phys_to_dma - set up conversion from DMA to physical addresses | |
89 | * @phys_idx: Top IOR_LSBITS bits of the DMA address, i.e. an index | |
90 | * into the array _phys_to_dma. | |
91 | * @delta: Value that, when added to the DMA address, will yield the | |
92 | * physical address | |
93 | * @s: Number of bytes in the section of memory with the given delta | |
94 | * between DMA and physical addresses. | |
95 | */ | |
96 | static void setup_phys_to_dma(phys_addr_t phys, dma_addr_t delta, phys_addr_t s) | |
97 | { | |
98 | int phys_idx, first_idx, last_idx; | |
99 | phys_addr_t first, last; | |
100 | ||
101 | /* | |
102 | * Calculate the first and last indices, rounding the first up and | |
103 | * the second down. | |
104 | */ | |
105 | first = phys & ~IOR_PHYS_GRAIN_MASK; | |
106 | last = (phys + s - 1) & ~IOR_PHYS_GRAIN_MASK; | |
107 | first_idx = first >> IOR_LSBITS; /* Convert to indices */ | |
108 | last_idx = last >> IOR_LSBITS; | |
109 | ||
110 | for (phys_idx = first_idx; phys_idx <= last_idx; phys_idx++) | |
111 | _ior_phys_to_dma[phys_idx].offset = delta >> IOR_PHYS_SHIFT; | |
112 | } | |
113 | ||
114 | /** | |
115 | * ioremap_add_map - add to the physical and DMA address conversion arrays | |
116 | * @phys: Process's view of the address of the start of the memory chunk | |
117 | * @dma: DMA address of the start of the memory chunk | |
118 | * @size: Size, in bytes, of the chunk of memory | |
119 | * | |
120 | * NOTE: It might be obvious, but the assumption is that all @size bytes have | |
121 | * the same offset between the physical address and the DMA address. | |
122 | */ | |
123 | void ioremap_add_map(phys_addr_t phys, phys_addr_t dma, phys_addr_t size) | |
124 | { | |
125 | if (size == 0) | |
126 | return; | |
127 | ||
128 | if ((dma & IOR_DMA_GRAIN_MASK) != 0 || | |
129 | (phys & IOR_PHYS_GRAIN_MASK) != 0 || | |
130 | (size & IOR_PHYS_GRAIN_MASK) != 0) | |
131 | pr_crit("Memory allocation must be in chunks of 0x%x bytes\n", | |
132 | IOR_PHYS_GRAIN); | |
133 | ||
134 | setup_dma_to_phys(dma, phys - dma, size); | |
135 | setup_phys_to_dma(phys, dma - phys, size); | |
136 | } |