drivers/xen/xen-pciback/conf_space_quirks.c

   1 /*
   2  * PCI Backend - Handle special overlays for broken devices.
   3  *
   4  * Author: Ryan Wilson <hap9@epoch.ncsc.mil>
   5  * Author: Chris Bookholt <hap10@epoch.ncsc.mil>
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/pci.h>
  10 #include "pciback.h"
  11 #include "conf_space.h"
  12 #include "conf_space_quirks.h"
  13
  14 LIST_HEAD(xen_pcibk_quirks);
  15 static inline const struct pci_device_id *
  16 match_one_device(const struct pci_device_id *id, const struct pci_dev *dev)
  17 {
  18         if ((id->vendor == PCI_ANY_ID || id->vendor == dev->vendor) &&
  19             (id->device == PCI_ANY_ID || id->device == dev->device) &&
  20             (id->subvendor == PCI_ANY_ID ||
  21                                 id->subvendor == dev->subsystem_vendor) &&
  22             (id->subdevice == PCI_ANY_ID ||
  23                                 id->subdevice == dev->subsystem_device) &&
  24             !((id->class ^ dev->class) & id->class_mask))
  25                 return id;
  26         return NULL;
  27 }
  28
  29 static struct xen_pcibk_config_quirk *xen_pcibk_find_quirk(struct pci_dev *dev)
  30 {
  31         struct xen_pcibk_config_quirk *tmp_quirk;
  32
  33         list_for_each_entry(tmp_quirk, &xen_pcibk_quirks, quirks_list)
  34                 if (match_one_device(&tmp_quirk->devid, dev) != NULL)
  35                         goto out;
  36         tmp_quirk = NULL;
  37         printk(KERN_DEBUG DRV_NAME
  38                ": quirk didn't match any device known\n");
  39 out:
  40         return tmp_quirk;
  41 }
  42
  43 static inline void register_quirk(struct xen_pcibk_config_quirk *quirk)
  44 {
  45         list_add_tail(&quirk->quirks_list, &xen_pcibk_quirks);
  46 }
  47
  48 int xen_pcibk_field_is_dup(struct pci_dev *dev, unsigned int reg)
  49 {
  50         int ret = 0;
  51         struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev);
  52         struct config_field_entry *cfg_entry;
  53
  54         list_for_each_entry(cfg_entry, &dev_data->config_fields, list) {
  55                 if (OFFSET(cfg_entry) == reg) {
  56                         ret = 1;
  57                         break;
  58                 }
  59         }
  60         return ret;
  61 }
  62
  63 int xen_pcibk_config_quirks_add_field(struct pci_dev *dev, struct config_field
  64                                     *field)
  65 {
  66         int err = 0;
  67
  68         switch (field->size) {
  69         case 1:
  70                 field->u.b.read = xen_pcibk_read_config_byte;
  71                 field->u.b.write = xen_pcibk_write_config_byte;
  72                 break;
  73         case 2:
  74                 field->u.w.read = xen_pcibk_read_config_word;
  75                 field->u.w.write = xen_pcibk_write_config_word;
  76                 break;
  77         case 4:
  78                 field->u.dw.read = xen_pcibk_read_config_dword;
  79                 field->u.dw.write = xen_pcibk_write_config_dword;
  80                 break;
  81         default:
  82                 err = -EINVAL;
  83                 goto out;
  84         }
  85
  86         xen_pcibk_config_add_field(dev, field);
  87
  88 out:
  89         return err;
  90 }
  91
  92 int xen_pcibk_config_quirks_init(struct pci_dev *dev)
  93 {
  94         struct xen_pcibk_config_quirk *quirk;
  95         int ret = 0;
  96
  97         quirk = kzalloc(sizeof(*quirk), GFP_ATOMIC);
  98         if (!quirk) {
  99                 ret = -ENOMEM;
 100                 goto out;
 101         }
 102
 103         quirk->devid.vendor = dev->vendor;
 104         quirk->devid.device = dev->device;
 105         quirk->devid.subvendor = dev->subsystem_vendor;
 106         quirk->devid.subdevice = dev->subsystem_device;
 107         quirk->devid.class = 0;
 108         quirk->devid.class_mask = 0;
 109         quirk->devid.driver_data = 0UL;
 110
 111         quirk->pdev = dev;
 112
 113         register_quirk(quirk);
 114 out:
 115         return ret;
 116 }
 117
 118 void xen_pcibk_config_field_free(struct config_field *field)
 119 {
 120         kfree(field);
 121 }
 122
 123 int xen_pcibk_config_quirk_release(struct pci_dev *dev)
 124 {
 125         struct xen_pcibk_config_quirk *quirk;
 126         int ret = 0;
 127
 128         quirk = xen_pcibk_find_quirk(dev);
 129         if (!quirk) {
 130                 ret = -ENXIO;
 131                 goto out;
 132         }
 133
 134         list_del(&quirk->quirks_list);
 135         kfree(quirk);
 136
 137 out:
 138         return ret;
 139 }