1 | /* Driver Manager Driver Translate Interface Implementation |
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2 | * |
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3 | * COPYRIGHT (c) 2010 Cobham Gaisler AB. |
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4 | * |
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5 | * The license and distribution terms for this file may be |
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6 | * found in the file LICENSE in this distribution or at |
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7 | * http://www.rtems.org/license/LICENSE. |
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8 | */ |
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9 | |
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10 | /* |
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11 | * Used by device drivers. The functions rely on that the parent bus driver |
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12 | * has implemented the neccessary operations correctly. |
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13 | * |
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14 | * The translate functions are used to translate addresses between buses |
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15 | * for DMA cores located on a "remote" bus, or for memory-mapped obtaining |
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16 | * an address that can be used to access an remote bus. |
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17 | * |
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18 | * For example, PCI I/O might be memory-mapped at the PCI Host bridge, |
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19 | * say address 0xfff10000-0xfff1ffff is mapped to the PCI I/O address |
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20 | * of 0x00000000-0x0000ffff. The PCI Host bridge driver may then set up |
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21 | * a map so that a driver that get PCI address 0x100 can translate that |
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22 | * into 0xfff10100. |
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23 | */ |
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24 | |
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25 | #include <stdio.h> |
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26 | #include <stdlib.h> |
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27 | #include <string.h> |
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28 | |
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29 | #include <drvmgr/drvmgr.h> |
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30 | #include "drvmgr_internal.h" |
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31 | |
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32 | unsigned int drvmgr_translate_bus( |
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33 | struct drvmgr_bus *from, |
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34 | struct drvmgr_bus *to, |
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35 | int reverse, |
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36 | void *src_address, |
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37 | void **dst_address) |
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38 | { |
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39 | struct drvmgr_bus *path[16]; |
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40 | int dir, levels, i; |
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41 | void *dst, *from_adr, *to_adr; |
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42 | struct drvmgr_map_entry *map; |
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43 | struct drvmgr_bus *bus; |
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44 | unsigned int sz; |
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45 | struct drvmgr_bus *bus_bot, *bus_top; |
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46 | |
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47 | dst = src_address; |
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48 | sz = 0xffffffff; |
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49 | |
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50 | if (from == to) /* no need translating addresses when on same bus */ |
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51 | goto out; |
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52 | |
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53 | /* Always find translation path from remote bus towards root bus. All |
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54 | * buses have root bus has parent at some level |
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55 | */ |
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56 | if (from->depth > to->depth) { |
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57 | bus_bot = from; |
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58 | bus_top = to; |
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59 | dir = 0; |
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60 | } else { |
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61 | bus_bot = to; |
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62 | bus_top = from; |
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63 | dir = 1; |
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64 | } |
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65 | levels = bus_bot->depth - bus_top->depth; |
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66 | if (levels >= 16) |
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67 | return 0; /* Does not support such a big depth */ |
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68 | i = 0; |
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69 | while ((bus_bot != NULL) && bus_bot != bus_top) { |
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70 | if (dir) |
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71 | path[(levels - 1) - i] = bus_bot; |
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72 | else |
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73 | path[i] = bus_bot; |
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74 | i++; |
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75 | bus_bot = bus_bot->dev->parent; |
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76 | } |
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77 | if (bus_bot == NULL) |
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78 | return 0; /* from -> to is not linearly connected */ |
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79 | |
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80 | for (i = 0; i < levels; i++) { |
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81 | bus = path[i]; |
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82 | |
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83 | if ((dir && reverse) || (!dir && !reverse)) |
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84 | map = bus->maps_up; |
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85 | else |
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86 | map = bus->maps_down; |
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87 | |
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88 | if (map == NULL) |
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89 | continue; /* No translation needed - 1:1 mapping */ |
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90 | |
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91 | if (map == DRVMGR_TRANSLATE_NO_BRIDGE) { |
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92 | sz = 0; |
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93 | break; /* No bridge interface in this direction */ |
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94 | } |
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95 | |
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96 | while (map->size != 0) { |
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97 | if (reverse) { |
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98 | /* Opposite direction */ |
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99 | from_adr = map->to_adr; |
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100 | to_adr = map->from_adr; |
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101 | } else { |
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102 | from_adr = map->from_adr; |
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103 | to_adr = map->to_adr; |
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104 | } |
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105 | |
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106 | if ((dst >= from_adr) && |
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107 | (dst <= (from_adr + (map->size - 1)))) { |
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108 | if (((from_adr + (map->size - 1)) - dst) < sz) |
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109 | sz = (from_adr + (map->size - 1)) - dst; |
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110 | dst = (dst - from_adr) + to_adr; |
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111 | break; |
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112 | } |
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113 | map++; |
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114 | } |
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115 | /* quit if no matching translation information */ |
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116 | if (map->size == 0) { |
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117 | sz = 0; |
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118 | break; |
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119 | } |
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120 | } |
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121 | |
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122 | out: |
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123 | if (dst_address) |
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124 | *dst_address = dst; |
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125 | |
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126 | return sz; |
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127 | } |
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128 | |
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129 | unsigned int drvmgr_translate( |
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130 | struct drvmgr_dev *dev, |
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131 | unsigned int options, |
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132 | void *src_address, |
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133 | void **dst_address) |
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134 | { |
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135 | struct drvmgr_bus *to, *from; |
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136 | int rev = 0; |
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137 | |
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138 | rev = (~options) & 1; |
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139 | if ((options == CPUMEM_TO_DMA) || (options == DMAMEM_FROM_CPU)) { |
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140 | from = drvmgr.root_dev.bus; |
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141 | to = dev->parent; |
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142 | } else { /* CPUMEM_FROM_DMA || DMAMEM_TO_CPU */ |
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143 | from = dev->parent; |
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144 | to = drvmgr.root_dev.bus; |
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145 | } |
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146 | |
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147 | return drvmgr_translate_bus(from, to, rev, src_address, dst_address); |
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148 | } |
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