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#define dev_fmt(fmt) DRV_NAME ": " fmt
  10
  11#include <linux/kernel.h>
  12#include <linux/pci.h>
  13#include "pciback.h"
  14#include "conf_space.h"
  15#include "conf_space_quirks.h"
  16
  17LIST_HEAD(xen_pcibk_quirks);
  18static inline const struct pci_device_id *
  19match_one_device(const struct pci_device_id *id, const struct pci_dev *dev)
  20{
  21        if ((id->vendor == PCI_ANY_ID || id->vendor == dev->vendor) &&
  22            (id->device == PCI_ANY_ID || id->device == dev->device) &&
  23            (id->subvendor == PCI_ANY_ID ||
  24                                id->subvendor == dev->subsystem_vendor) &&
  25            (id->subdevice == PCI_ANY_ID ||
  26                                id->subdevice == dev->subsystem_device) &&
  27            !((id->class ^ dev->class) & id->class_mask))
  28                return id;
  29        return NULL;
  30}
  31
  32static struct xen_pcibk_config_quirk *xen_pcibk_find_quirk(struct pci_dev *dev)
  33{
  34        struct xen_pcibk_config_quirk *tmp_quirk;
  35
  36        list_for_each_entry(tmp_quirk, &xen_pcibk_quirks, quirks_list)
  37                if (match_one_device(&tmp_quirk->devid, dev) != NULL)
  38                        goto out;
  39        tmp_quirk = NULL;
  40        dev_printk(KERN_DEBUG, &dev->dev,
  41                   "quirk didn't match any device known\n");
  42out:
  43        return tmp_quirk;
  44}
  45
  46static inline void register_quirk(struct xen_pcibk_config_quirk *quirk)
  47{
  48        list_add_tail(&quirk->quirks_list, &xen_pcibk_quirks);
  49}
  50
  51int xen_pcibk_field_is_dup(struct pci_dev *dev, unsigned int reg)
  52{
  53        int ret = 0;
  54        struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev);
  55        struct config_field_entry *cfg_entry;
  56
  57        list_for_each_entry(cfg_entry, &dev_data->config_fields, list) {
  58                if (OFFSET(cfg_entry) == reg) {
  59                        ret = 1;
  60                        break;
  61                }
  62        }
  63        return ret;
  64}
  65
  66int xen_pcibk_config_quirks_add_field(struct pci_dev *dev, struct config_field
  67                                    *field)
  68{
  69        int err = 0;
  70
  71        switch (field->size) {
  72        case 1:
  73                field->u.b.read = xen_pcibk_read_config_byte;
  74                field->u.b.write = xen_pcibk_write_config_byte;
  75                break;
  76        case 2:
  77                field->u.w.read = xen_pcibk_read_config_word;
  78                field->u.w.write = xen_pcibk_write_config_word;
  79                break;
  80        case 4:
  81                field->u.dw.read = xen_pcibk_read_config_dword;
  82                field->u.dw.write = xen_pcibk_write_config_dword;
  83                break;
  84        default:
  85                err = -EINVAL;
  86                goto out;
  87        }
  88
  89        xen_pcibk_config_add_field(dev, field);
  90
  91out:
  92        return err;
  93}
  94
  95int xen_pcibk_config_quirks_init(struct pci_dev *dev)
  96{
  97        struct xen_pcibk_config_quirk *quirk;
  98        int ret = 0;
  99
 100        quirk = kzalloc(sizeof(*quirk), GFP_KERNEL);
 101        if (!quirk) {
 102                ret = -ENOMEM;
 103                goto out;
 104        }
 105
 106        quirk->devid.vendor = dev->vendor;
 107        quirk->devid.device = dev->device;
 108        quirk->devid.subvendor = dev->subsystem_vendor;
 109        quirk->devid.subdevice = dev->subsystem_device;
 110        quirk->devid.class = 0;
 111        quirk->devid.class_mask = 0;
 112        quirk->devid.driver_data = 0UL;
 113
 114        quirk->pdev = dev;
 115
 116        register_quirk(quirk);
 117out:
 118        return ret;
 119}
 120
 121void xen_pcibk_config_field_free(struct config_field *field)
 122{
 123        kfree(field);
 124}
 125
 126int xen_pcibk_config_quirk_release(struct pci_dev *dev)
 127{
 128        struct xen_pcibk_config_quirk *quirk;
 129        int ret = 0;
 130
 131        quirk = xen_pcibk_find_quirk(dev);
 132        if (!quirk) {
 133                ret = -ENXIO;
 134                goto out;
 135        }
 136
 137        list_del(&quirk->quirks_list);
 138        kfree(quirk);
 139
 140out:
 141        return ret;
 142}
 143