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
15 LIST_HEAD(xen_pcibk_quirks);
16 static inline const struct pci_device_id *
match_one_device(const struct pci_device_id * id,const struct pci_dev * dev)17 match_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
xen_pcibk_find_quirk(struct pci_dev * dev)30 static 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");
40 out:
41 return tmp_quirk;
42 }
43
register_quirk(struct xen_pcibk_config_quirk * quirk)44 static inline void register_quirk(struct xen_pcibk_config_quirk *quirk)
45 {
46 list_add_tail(&quirk->quirks_list, &xen_pcibk_quirks);
47 }
48
xen_pcibk_field_is_dup(struct pci_dev * dev,unsigned int reg)49 int 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
xen_pcibk_config_quirks_add_field(struct pci_dev * dev,struct config_field * field)64 int 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
89 out:
90 return err;
91 }
92
xen_pcibk_config_quirks_init(struct pci_dev * dev)93 int 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);
115 out:
116 return ret;
117 }
118
xen_pcibk_config_field_free(struct config_field * field)119 void xen_pcibk_config_field_free(struct config_field *field)
120 {
121 kfree(field);
122 }
123
xen_pcibk_config_quirk_release(struct pci_dev * dev)124 int 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
138 out:
139 return ret;
140 }
141