1 | /* |
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2 | * PCI Backend - Provides a Virtual PCI bus (with real devices) |
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3 | * to the frontend |
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4 | * |
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5 | * Author: Ryan Wilson <hap9@epoch.ncsc.mil> (vpci.c) |
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6 | * Author: Tristan Gingold <tristan.gingold@bull.net>, from vpci.c |
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7 | */ |
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8 | |
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9 | #include <linux/list.h> |
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10 | #include <linux/slab.h> |
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11 | #include <linux/pci.h> |
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12 | #include <linux/spinlock.h> |
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13 | #include "pciback.h" |
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14 | |
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15 | /* There are at most 32 slots in a pci bus. */ |
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16 | #define PCI_SLOT_MAX 32 |
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17 | |
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18 | #define PCI_BUS_NBR 2 |
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19 | |
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20 | struct slot_dev_data { |
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21 | /* Access to dev_list must be protected by lock */ |
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22 | struct pci_dev *slots[PCI_BUS_NBR][PCI_SLOT_MAX]; |
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23 | spinlock_t lock; |
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24 | }; |
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25 | |
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26 | struct pci_dev *pciback_get_pci_dev(struct pciback_device *pdev, |
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27 | unsigned int domain, unsigned int bus, |
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28 | unsigned int devfn) |
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29 | { |
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30 | struct pci_dev *dev = NULL; |
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31 | struct slot_dev_data *slot_dev = pdev->pci_dev_data; |
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32 | unsigned long flags; |
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33 | |
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34 | if (domain != 0 || PCI_FUNC(devfn) != 0) |
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35 | return NULL; |
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36 | |
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37 | if (PCI_SLOT(devfn) >= PCI_SLOT_MAX || bus >= PCI_BUS_NBR) |
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38 | return NULL; |
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39 | |
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40 | spin_lock_irqsave(&slot_dev->lock, flags); |
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41 | dev = slot_dev->slots[bus][PCI_SLOT(devfn)]; |
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42 | spin_unlock_irqrestore(&slot_dev->lock, flags); |
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43 | |
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44 | return dev; |
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45 | } |
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46 | |
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47 | int pciback_add_pci_dev(struct pciback_device *pdev, struct pci_dev *dev) |
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48 | { |
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49 | int err = 0, slot, bus; |
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50 | struct slot_dev_data *slot_dev = pdev->pci_dev_data; |
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51 | unsigned long flags; |
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52 | |
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53 | if ((dev->class >> 24) == PCI_BASE_CLASS_BRIDGE) { |
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54 | err = -EFAULT; |
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55 | xenbus_dev_fatal(pdev->xdev, err, |
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56 | "Can't export bridges on the virtual PCI bus"); |
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57 | goto out; |
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58 | } |
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59 | |
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60 | spin_lock_irqsave(&slot_dev->lock, flags); |
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61 | |
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62 | /* Assign to a new slot on the virtual PCI bus */ |
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63 | for (bus = 0; bus < PCI_BUS_NBR; bus++) |
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64 | for (slot = 0; slot < PCI_SLOT_MAX; slot++) { |
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65 | if (slot_dev->slots[bus][slot] == NULL) { |
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66 | printk(KERN_INFO |
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67 | "pciback: slot: %s: assign to virtual slot %d, bus %d\n", |
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68 | pci_name(dev), slot, bus); |
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69 | slot_dev->slots[bus][slot] = dev; |
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70 | goto unlock; |
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71 | } |
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72 | } |
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73 | |
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74 | err = -ENOMEM; |
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75 | xenbus_dev_fatal(pdev->xdev, err, |
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76 | "No more space on root virtual PCI bus"); |
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77 | |
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78 | unlock: |
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79 | spin_unlock_irqrestore(&slot_dev->lock, flags); |
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80 | out: |
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81 | return err; |
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82 | } |
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83 | |
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84 | void pciback_release_pci_dev(struct pciback_device *pdev, struct pci_dev *dev) |
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85 | { |
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86 | int slot, bus; |
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87 | struct slot_dev_data *slot_dev = pdev->pci_dev_data; |
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88 | struct pci_dev *found_dev = NULL; |
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89 | unsigned long flags; |
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90 | |
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91 | spin_lock_irqsave(&slot_dev->lock, flags); |
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92 | |
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93 | for (bus = 0; bus < PCI_BUS_NBR; bus++) |
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94 | for (slot = 0; slot < PCI_SLOT_MAX; slot++) { |
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95 | if (slot_dev->slots[bus][slot] == dev) { |
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96 | slot_dev->slots[bus][slot] = NULL; |
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97 | found_dev = dev; |
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98 | goto out; |
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99 | } |
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100 | } |
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101 | |
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102 | out: |
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103 | spin_unlock_irqrestore(&slot_dev->lock, flags); |
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104 | |
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105 | if (found_dev) |
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106 | pcistub_put_pci_dev(found_dev); |
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107 | } |
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108 | |
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109 | int pciback_init_devices(struct pciback_device *pdev) |
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110 | { |
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111 | int slot, bus; |
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112 | struct slot_dev_data *slot_dev; |
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113 | |
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114 | slot_dev = kmalloc(sizeof(*slot_dev), GFP_KERNEL); |
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115 | if (!slot_dev) |
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116 | return -ENOMEM; |
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117 | |
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118 | spin_lock_init(&slot_dev->lock); |
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119 | |
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120 | for (bus = 0; bus < PCI_BUS_NBR; bus++) |
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121 | for (slot = 0; slot < PCI_SLOT_MAX; slot++) |
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122 | slot_dev->slots[bus][slot] = NULL; |
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123 | |
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124 | pdev->pci_dev_data = slot_dev; |
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125 | |
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126 | return 0; |
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127 | } |
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128 | |
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129 | int pciback_publish_pci_roots(struct pciback_device *pdev, |
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130 | publish_pci_root_cb publish_cb) |
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131 | { |
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132 | /* The Virtual PCI bus has only one root */ |
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133 | return publish_cb(pdev, 0, 0); |
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134 | } |
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135 | |
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136 | void pciback_release_devices(struct pciback_device *pdev) |
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137 | { |
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138 | int slot, bus; |
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139 | struct slot_dev_data *slot_dev = pdev->pci_dev_data; |
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140 | struct pci_dev *dev; |
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141 | |
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142 | for (bus = 0; bus < PCI_BUS_NBR; bus++) |
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143 | for (slot = 0; slot < PCI_SLOT_MAX; slot++) { |
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144 | dev = slot_dev->slots[bus][slot]; |
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145 | if (dev != NULL) |
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146 | pcistub_put_pci_dev(dev); |
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147 | } |
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148 | |
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149 | kfree(slot_dev); |
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150 | pdev->pci_dev_data = NULL; |
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151 | } |
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