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Rev | Author | Line No. | Line |
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587 | giacomo | 1 | /* |
2 | * direct.c - Low-level direct PCI config space access |
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3 | */ |
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4 | |||
5 | #include <linuxcomp.h> |
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6 | |||
7 | #include <linux/pci.h> |
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8 | #include <linux/init.h> |
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9 | #include "pci2.h" |
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10 | |||
11 | /* |
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12 | * Functions for accessing PCI configuration space with type 1 accesses |
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13 | */ |
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14 | |||
15 | #define PCI_CONF1_ADDRESS(bus, devfn, reg) \ |
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16 | (0x80000000 | (bus << 16) | (devfn << 8) | (reg & ~3)) |
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17 | |||
18 | static int pci_conf1_read (int seg, int bus, int devfn, int reg, int len, u32 *value) |
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19 | { |
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20 | unsigned long flags; |
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21 | |||
22 | if (!value || (bus > 255) || (devfn > 255) || (reg > 255)) |
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23 | return -EINVAL; |
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24 | |||
25 | spin_lock_irqsave(&pci_config_lock, flags); |
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26 | |||
27 | outl(PCI_CONF1_ADDRESS(bus, devfn, reg), 0xCF8); |
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28 | |||
29 | switch (len) { |
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30 | case 1: |
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31 | *value = inb(0xCFC + (reg & 3)); |
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32 | break; |
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33 | case 2: |
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34 | *value = inw(0xCFC + (reg & 2)); |
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35 | break; |
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36 | case 4: |
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37 | *value = inl(0xCFC); |
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38 | break; |
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39 | } |
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40 | |||
41 | spin_unlock_irqrestore(&pci_config_lock, flags); |
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42 | |||
43 | return 0; |
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44 | } |
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45 | |||
46 | static int pci_conf1_write (int seg, int bus, int devfn, int reg, int len, u32 value) |
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47 | { |
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48 | unsigned long flags; |
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49 | |||
50 | if ((bus > 255) || (devfn > 255) || (reg > 255)) |
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51 | return -EINVAL; |
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52 | |||
53 | spin_lock_irqsave(&pci_config_lock, flags); |
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54 | |||
55 | outl(PCI_CONF1_ADDRESS(bus, devfn, reg), 0xCF8); |
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56 | |||
57 | switch (len) { |
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58 | case 1: |
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59 | outb((u8)value, 0xCFC + (reg & 3)); |
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60 | break; |
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61 | case 2: |
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62 | outw((u16)value, 0xCFC + (reg & 2)); |
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63 | break; |
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64 | case 4: |
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65 | outl((u32)value, 0xCFC); |
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66 | break; |
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67 | } |
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68 | |||
69 | spin_unlock_irqrestore(&pci_config_lock, flags); |
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70 | |||
71 | return 0; |
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72 | } |
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73 | |||
74 | #undef PCI_CONF1_ADDRESS |
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75 | |||
76 | struct pci_raw_ops pci_direct_conf1 = { |
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77 | .read = pci_conf1_read, |
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78 | .write = pci_conf1_write, |
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79 | }; |
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80 | |||
81 | |||
82 | /* |
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83 | * Functions for accessing PCI configuration space with type 2 accesses |
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84 | */ |
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85 | |||
86 | #define PCI_CONF2_ADDRESS(dev, reg) (u16)(0xC000 | (dev << 8) | reg) |
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87 | |||
88 | static int pci_conf2_read(int seg, int bus, int devfn, int reg, int len, u32 *value) |
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89 | { |
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90 | unsigned long flags; |
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91 | int dev, fn; |
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92 | |||
93 | if (!value || (bus > 255) || (devfn > 255) || (reg > 255)) |
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94 | return -EINVAL; |
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95 | |||
96 | dev = PCI_SLOT(devfn); |
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97 | fn = PCI_FUNC(devfn); |
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98 | |||
99 | if (dev & 0x10) |
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100 | return PCIBIOS_DEVICE_NOT_FOUND; |
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101 | |||
102 | spin_lock_irqsave(&pci_config_lock, flags); |
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103 | |||
104 | outb((u8)(0xF0 | (fn << 1)), 0xCF8); |
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105 | outb((u8)bus, 0xCFA); |
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106 | |||
107 | switch (len) { |
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108 | case 1: |
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109 | *value = inb(PCI_CONF2_ADDRESS(dev, reg)); |
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110 | break; |
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111 | case 2: |
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112 | *value = inw(PCI_CONF2_ADDRESS(dev, reg)); |
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113 | break; |
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114 | case 4: |
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115 | *value = inl(PCI_CONF2_ADDRESS(dev, reg)); |
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116 | break; |
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117 | } |
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118 | |||
119 | outb(0, 0xCF8); |
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120 | |||
121 | spin_unlock_irqrestore(&pci_config_lock, flags); |
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122 | |||
123 | return 0; |
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124 | } |
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125 | |||
126 | static int pci_conf2_write (int seg, int bus, int devfn, int reg, int len, u32 value) |
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127 | { |
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128 | unsigned long flags; |
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129 | int dev, fn; |
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130 | |||
131 | if ((bus > 255) || (devfn > 255) || (reg > 255)) |
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132 | return -EINVAL; |
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133 | |||
134 | dev = PCI_SLOT(devfn); |
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135 | fn = PCI_FUNC(devfn); |
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136 | |||
137 | if (dev & 0x10) |
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138 | return PCIBIOS_DEVICE_NOT_FOUND; |
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139 | |||
140 | spin_lock_irqsave(&pci_config_lock, flags); |
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141 | |||
142 | outb((u8)(0xF0 | (fn << 1)), 0xCF8); |
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143 | outb((u8)bus, 0xCFA); |
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144 | |||
145 | switch (len) { |
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146 | case 1: |
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147 | outb((u8)value, PCI_CONF2_ADDRESS(dev, reg)); |
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148 | break; |
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149 | case 2: |
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150 | outw((u16)value, PCI_CONF2_ADDRESS(dev, reg)); |
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151 | break; |
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152 | case 4: |
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153 | outl((u32)value, PCI_CONF2_ADDRESS(dev, reg)); |
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154 | break; |
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155 | } |
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156 | |||
157 | outb(0, 0xCF8); |
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158 | |||
159 | spin_unlock_irqrestore(&pci_config_lock, flags); |
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160 | |||
161 | return 0; |
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162 | } |
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163 | |||
164 | #undef PCI_CONF2_ADDRESS |
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165 | |||
166 | static struct pci_raw_ops pci_direct_conf2 = { |
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167 | .read = pci_conf2_read, |
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168 | .write = pci_conf2_write, |
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169 | }; |
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170 | |||
171 | |||
172 | /* |
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173 | * Before we decide to use direct hardware access mechanisms, we try to do some |
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174 | * trivial checks to ensure it at least _seems_ to be working -- we just test |
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175 | * whether bus 00 contains a host bridge (this is similar to checking |
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176 | * techniques used in XFree86, but ours should be more reliable since we |
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177 | * attempt to make use of direct access hints provided by the PCI BIOS). |
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178 | * |
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179 | * This should be close to trivial, but it isn't, because there are buggy |
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180 | * chipsets (yes, you guessed it, by Intel and Compaq) that have no class ID. |
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181 | */ |
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182 | static int __init pci_sanity_check(struct pci_raw_ops *o) |
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183 | { |
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184 | u32 x = 0; |
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185 | int devfn; |
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186 | |||
187 | if (pci_probe & PCI_NO_CHECKS) |
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188 | return 1; |
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189 | |||
190 | for (devfn = 0; devfn < 0x100; devfn++) { |
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191 | if (o->read(0, 0, devfn, PCI_CLASS_DEVICE, 2, &x)) |
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192 | continue; |
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193 | if (x == PCI_CLASS_BRIDGE_HOST || x == PCI_CLASS_DISPLAY_VGA) |
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194 | return 1; |
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195 | |||
196 | if (o->read(0, 0, devfn, PCI_VENDOR_ID, 2, &x)) |
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197 | continue; |
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198 | if (x == PCI_VENDOR_ID_INTEL || x == PCI_VENDOR_ID_COMPAQ) |
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199 | return 1; |
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200 | } |
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201 | |||
202 | DBG("PCI: Sanity check failed\n"); |
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203 | return 0; |
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204 | } |
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205 | |||
206 | static int __init pci_check_type1(void) |
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207 | { |
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208 | unsigned long flags; |
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209 | unsigned int tmp; |
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210 | int works = 0; |
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211 | |||
212 | local_irq_save(flags); |
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213 | |||
214 | outb(0x01, 0xCFB); |
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215 | tmp = inl(0xCF8); |
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216 | outl(0x80000000, 0xCF8); |
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217 | if (inl(0xCF8) == 0x80000000 && pci_sanity_check(&pci_direct_conf1)) { |
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218 | works = 1; |
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219 | } |
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220 | outl(tmp, 0xCF8); |
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221 | local_irq_restore(flags); |
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222 | |||
223 | return works; |
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224 | } |
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225 | |||
226 | static int __init pci_check_type2(void) |
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227 | { |
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228 | unsigned long flags; |
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229 | int works = 0; |
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230 | |||
231 | local_irq_save(flags); |
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232 | |||
233 | outb(0x00, 0xCFB); |
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234 | outb(0x00, 0xCF8); |
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235 | outb(0x00, 0xCFA); |
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236 | if (inb(0xCF8) == 0x00 && inb(0xCFA) == 0x00 && |
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237 | pci_sanity_check(&pci_direct_conf2)) { |
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238 | works = 1; |
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239 | } |
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240 | |||
241 | local_irq_restore(flags); |
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242 | |||
243 | return works; |
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244 | } |
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245 | |||
246 | int __init pci_direct_init(void) |
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247 | { |
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248 | struct resource *region, *region2; |
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249 | |||
250 | if ((pci_probe & PCI_PROBE_CONF1) == 0) |
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251 | goto type2; |
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252 | region = request_region(0xCF8, 8, "PCI conf1"); |
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253 | if (!region) |
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254 | goto type2; |
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255 | |||
256 | if (pci_check_type1()) { |
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257 | printk(KERN_INFO "PCI: Using configuration type 1\n"); |
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258 | raw_pci_ops = &pci_direct_conf1; |
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259 | return 0; |
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260 | } |
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261 | release_resource(region); |
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262 | |||
263 | type2: |
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264 | if ((!pci_probe & PCI_PROBE_CONF2) == 0) |
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265 | goto out; |
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266 | region = request_region(0xCF8, 4, "PCI conf2"); |
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267 | if (!region) |
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268 | goto out; |
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269 | region2 = request_region(0xC000, 0x1000, "PCI conf2"); |
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270 | if (!region2) |
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271 | goto fail2; |
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272 | |||
273 | if (pci_check_type2()) { |
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274 | printk(KERN_INFO "PCI: Using configuration type 2\n"); |
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275 | raw_pci_ops = &pci_direct_conf2; |
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276 | return 0; |
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277 | } |
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278 | |||
279 | release_resource(region2); |
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280 | fail2: |
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281 | release_resource(region); |
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282 | |||
283 | out: |
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284 | return 0; |
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285 | } |
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286 | |||
287 | arch_initcall(pci_direct_init); |