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
17 LIST_HEAD(xen_pcibk_quirks);
18 static inline const struct pci_device_id *
match_one_device(const struct pci_device_id * id,const struct pci_dev * dev)19 match_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
xen_pcibk_find_quirk(struct pci_dev * dev)32 static 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");
42 out:
43 return tmp_quirk;
44 }
45
register_quirk(struct xen_pcibk_config_quirk * quirk)46 static inline void register_quirk(struct xen_pcibk_config_quirk *quirk)
47 {
48 list_add_tail(&quirk->quirks_list, &xen_pcibk_quirks);
49 }
50
xen_pcibk_field_is_dup(struct pci_dev * dev,unsigned int reg)51 int 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
xen_pcibk_config_quirks_add_field(struct pci_dev * dev,struct config_field * field)66 int 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
91 out:
92 return err;
93 }
94
xen_pcibk_config_quirks_init(struct pci_dev * dev)95 int 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);
117 out:
118 return ret;
119 }
120
xen_pcibk_config_field_free(struct config_field * field)121 void xen_pcibk_config_field_free(struct config_field *field)
122 {
123 kfree(field);
124 }
125
xen_pcibk_config_quirk_release(struct pci_dev * dev)126 int 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
140 out:
141 return ret;
142 }
143