LXR linux/drivers/xen/xen-pciback/conf_space

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * PCI Backend - Handle special overlays for broken devices.
   4 *
   5 * Author: Ryan Wilson <hap9@epoch.ncsc.mil>
   6 * Author: Chris Bookholt <hap10@epoch.ncsc.mil>
   7 */
   8
   9#include <linux/kernel.h>
  10#include <linux/pci.h>
  11#include "pciback.h"
  12#include "conf_space.h"
  13#include "conf_space_quirks.h"
  14
  15LIST_HEAD(xen_pcibk_quirks);
  16static inline const struct pci_device_id *
  17match_one_device(const struct pci_device_id *id, const struct pci_dev *dev)
  18{
  19        if ((id->vendor == PCI_ANY_ID || id->vendor == dev->vendor) &&
  20            (id->device == PCI_ANY_ID || id->device == dev->device) &&
  21            (id->subvendor == PCI_ANY_ID ||
  22                                id->subvendor == dev->subsystem_vendor) &&
  23            (id->subdevice == PCI_ANY_ID ||
  24                                id->subdevice == dev->subsystem_device) &&
  25            !((id->class ^ dev->class) & id->class_mask))
  26                return id;
  27        return NULL;
  28}
  29
  30static struct xen_pcibk_config_quirk *xen_pcibk_find_quirk(struct pci_dev *dev)
  31{
  32        struct xen_pcibk_config_quirk *tmp_quirk;
  33
  34        list_for_each_entry(tmp_quirk, &xen_pcibk_quirks, quirks_list)
  35                if (match_one_device(&tmp_quirk->devid, dev) != NULL)
  36                        goto out;
  37        tmp_quirk = NULL;
  38        printk(KERN_DEBUG DRV_NAME
  39               ": quirk didn't match any device known\n");
  40out:
  41        return tmp_quirk;
  42}
  43
  44static inline void register_quirk(struct xen_pcibk_config_quirk *quirk)
  45{
  46        list_add_tail(&quirk->quirks_list, &xen_pcibk_quirks);
  47}
  48
  49int xen_pcibk_field_is_dup(struct pci_dev *dev, unsigned int reg)
  50{
  51        int ret = 0;
  52        struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev);
  53        struct config_field_entry *cfg_entry;
  54
  55        list_for_each_entry(cfg_entry, &dev_data->config_fields, list) {
  56                if (OFFSET(cfg_entry) == reg) {
  57                        ret = 1;
  58                        break;
  59                }
  60        }
  61        return ret;
  62}
  63
  64int xen_pcibk_config_quirks_add_field(struct pci_dev *dev, struct config_field
  65                                    *field)
  66{
  67        int err = 0;
  68
  69        switch (field->size) {
  70        case 1:
  71                field->u.b.read = xen_pcibk_read_config_byte;
  72                field->u.b.write = xen_pcibk_write_config_byte;
  73                break;
  74        case 2:
  75                field->u.w.read = xen_pcibk_read_config_word;
  76                field->u.w.write = xen_pcibk_write_config_word;
  77                break;
  78        case 4:
  79                field->u.dw.read = xen_pcibk_read_config_dword;
  80                field->u.dw.write = xen_pcibk_write_config_dword;
  81                break;
  82        default:
  83                err = -EINVAL;
  84                goto out;
  85        }
  86
  87        xen_pcibk_config_add_field(dev, field);
  88
  89out:
  90        return err;
  91}
  92
  93int xen_pcibk_config_quirks_init(struct pci_dev *dev)
  94{
  95        struct xen_pcibk_config_quirk *quirk;
  96        int ret = 0;
  97
  98        quirk = kzalloc(sizeof(*quirk), GFP_KERNEL);
  99        if (!quirk) {
 100                ret = -ENOMEM;
 101                goto out;
 102        }
 103
 104        quirk->devid.vendor = dev->vendor;
 105        quirk->devid.device = dev->device;
 106        quirk->devid.subvendor = dev->subsystem_vendor;
 107        quirk->devid.subdevice = dev->subsystem_device;
 108        quirk->devid.class = 0;
 109        quirk->devid.class_mask = 0;
 110        quirk->devid.driver_data = 0UL;
 111
 112        quirk->pdev = dev;
 113
 114        register_quirk(quirk);
 115out:
 116        return ret;
 117}
 118
 119void xen_pcibk_config_field_free(struct config_field *field)
 120{
 121        kfree(field);
 122}
 123
 124int xen_pcibk_config_quirk_release(struct pci_dev *dev)
 125{
 126        struct xen_pcibk_config_quirk *quirk;
 127        int ret = 0;
 128
 129        quirk = xen_pcibk_find_quirk(dev);
 130        if (!quirk) {
 131                ret = -ENXIO;
 132                goto out;
 133        }
 134
 135        list_del(&quirk->quirks_list);
 136        kfree(quirk);
 137
 138out:
 139        return ret;
 140}
 141