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 }
140