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Commit | Line | Data |
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30edc14b KRW |
1 | /* |
2 | * PCI Backend - Functions for creating a virtual configuration space for | |
3 | * exported PCI Devices. | |
4 | * It's dangerous to allow PCI Driver Domains to change their | |
5 | * device's resources (memory, i/o ports, interrupts). We need to | |
6 | * restrict changes to certain PCI Configuration registers: | |
7 | * BARs, INTERRUPT_PIN, most registers in the header... | |
8 | * | |
9 | * Author: Ryan Wilson <hap9@epoch.ncsc.mil> | |
10 | */ | |
11 | ||
12 | #include <linux/kernel.h> | |
13 | #include <linux/pci.h> | |
14 | #include "pciback.h" | |
15 | #include "conf_space.h" | |
16 | #include "conf_space_quirks.h" | |
17 | ||
18 | static int permissive; | |
19 | module_param(permissive, bool, 0644); | |
20 | ||
21 | #define DEFINE_PCI_CONFIG(op, size, type) \ | |
22 | int pciback_##op##_config_##size \ | |
23 | (struct pci_dev *dev, int offset, type value, void *data) \ | |
24 | { \ | |
25 | return pci_##op##_config_##size(dev, offset, value); \ | |
26 | } | |
27 | ||
28 | DEFINE_PCI_CONFIG(read, byte, u8 *) | |
29 | DEFINE_PCI_CONFIG(read, word, u16 *) | |
30 | DEFINE_PCI_CONFIG(read, dword, u32 *) | |
31 | ||
32 | DEFINE_PCI_CONFIG(write, byte, u8) | |
33 | DEFINE_PCI_CONFIG(write, word, u16) | |
34 | DEFINE_PCI_CONFIG(write, dword, u32) | |
35 | ||
36 | static int conf_space_read(struct pci_dev *dev, | |
37 | const struct config_field_entry *entry, | |
38 | int offset, u32 *value) | |
39 | { | |
40 | int ret = 0; | |
41 | const struct config_field *field = entry->field; | |
42 | ||
43 | *value = 0; | |
44 | ||
45 | switch (field->size) { | |
46 | case 1: | |
47 | if (field->u.b.read) | |
48 | ret = field->u.b.read(dev, offset, (u8 *) value, | |
49 | entry->data); | |
50 | break; | |
51 | case 2: | |
52 | if (field->u.w.read) | |
53 | ret = field->u.w.read(dev, offset, (u16 *) value, | |
54 | entry->data); | |
55 | break; | |
56 | case 4: | |
57 | if (field->u.dw.read) | |
58 | ret = field->u.dw.read(dev, offset, value, entry->data); | |
59 | break; | |
60 | } | |
61 | return ret; | |
62 | } | |
63 | ||
64 | static int conf_space_write(struct pci_dev *dev, | |
65 | const struct config_field_entry *entry, | |
66 | int offset, u32 value) | |
67 | { | |
68 | int ret = 0; | |
69 | const struct config_field *field = entry->field; | |
70 | ||
71 | switch (field->size) { | |
72 | case 1: | |
73 | if (field->u.b.write) | |
74 | ret = field->u.b.write(dev, offset, (u8) value, | |
75 | entry->data); | |
76 | break; | |
77 | case 2: | |
78 | if (field->u.w.write) | |
79 | ret = field->u.w.write(dev, offset, (u16) value, | |
80 | entry->data); | |
81 | break; | |
82 | case 4: | |
83 | if (field->u.dw.write) | |
84 | ret = field->u.dw.write(dev, offset, value, | |
85 | entry->data); | |
86 | break; | |
87 | } | |
88 | return ret; | |
89 | } | |
90 | ||
91 | static inline u32 get_mask(int size) | |
92 | { | |
93 | if (size == 1) | |
94 | return 0xff; | |
95 | else if (size == 2) | |
96 | return 0xffff; | |
97 | else | |
98 | return 0xffffffff; | |
99 | } | |
100 | ||
101 | static inline int valid_request(int offset, int size) | |
102 | { | |
103 | /* Validate request (no un-aligned requests) */ | |
104 | if ((size == 1 || size == 2 || size == 4) && (offset % size) == 0) | |
105 | return 1; | |
106 | return 0; | |
107 | } | |
108 | ||
109 | static inline u32 merge_value(u32 val, u32 new_val, u32 new_val_mask, | |
110 | int offset) | |
111 | { | |
112 | if (offset >= 0) { | |
113 | new_val_mask <<= (offset * 8); | |
114 | new_val <<= (offset * 8); | |
115 | } else { | |
116 | new_val_mask >>= (offset * -8); | |
117 | new_val >>= (offset * -8); | |
118 | } | |
119 | val = (val & ~new_val_mask) | (new_val & new_val_mask); | |
120 | ||
121 | return val; | |
122 | } | |
123 | ||
124 | static int pcibios_err_to_errno(int err) | |
125 | { | |
126 | switch (err) { | |
127 | case PCIBIOS_SUCCESSFUL: | |
128 | return XEN_PCI_ERR_success; | |
129 | case PCIBIOS_DEVICE_NOT_FOUND: | |
130 | return XEN_PCI_ERR_dev_not_found; | |
131 | case PCIBIOS_BAD_REGISTER_NUMBER: | |
132 | return XEN_PCI_ERR_invalid_offset; | |
133 | case PCIBIOS_FUNC_NOT_SUPPORTED: | |
134 | return XEN_PCI_ERR_not_implemented; | |
135 | case PCIBIOS_SET_FAILED: | |
136 | return XEN_PCI_ERR_access_denied; | |
137 | } | |
138 | return err; | |
139 | } | |
140 | ||
141 | int pciback_config_read(struct pci_dev *dev, int offset, int size, | |
142 | u32 *ret_val) | |
143 | { | |
144 | int err = 0; | |
145 | struct pciback_dev_data *dev_data = pci_get_drvdata(dev); | |
146 | const struct config_field_entry *cfg_entry; | |
147 | const struct config_field *field; | |
148 | int req_start, req_end, field_start, field_end; | |
149 | /* if read fails for any reason, return 0 | |
150 | * (as if device didn't respond) */ | |
151 | u32 value = 0, tmp_val; | |
152 | ||
153 | if (unlikely(verbose_request)) | |
154 | printk(KERN_DEBUG "pciback: %s: read %d bytes at 0x%x\n", | |
155 | pci_name(dev), size, offset); | |
156 | ||
157 | if (!valid_request(offset, size)) { | |
158 | err = XEN_PCI_ERR_invalid_offset; | |
159 | goto out; | |
160 | } | |
161 | ||
162 | /* Get the real value first, then modify as appropriate */ | |
163 | switch (size) { | |
164 | case 1: | |
165 | err = pci_read_config_byte(dev, offset, (u8 *) &value); | |
166 | break; | |
167 | case 2: | |
168 | err = pci_read_config_word(dev, offset, (u16 *) &value); | |
169 | break; | |
170 | case 4: | |
171 | err = pci_read_config_dword(dev, offset, &value); | |
172 | break; | |
173 | } | |
174 | ||
175 | list_for_each_entry(cfg_entry, &dev_data->config_fields, list) { | |
176 | field = cfg_entry->field; | |
177 | ||
178 | req_start = offset; | |
179 | req_end = offset + size; | |
180 | field_start = OFFSET(cfg_entry); | |
181 | field_end = OFFSET(cfg_entry) + field->size; | |
182 | ||
183 | if ((req_start >= field_start && req_start < field_end) | |
184 | || (req_end > field_start && req_end <= field_end)) { | |
185 | err = conf_space_read(dev, cfg_entry, field_start, | |
186 | &tmp_val); | |
187 | if (err) | |
188 | goto out; | |
189 | ||
190 | value = merge_value(value, tmp_val, | |
191 | get_mask(field->size), | |
192 | field_start - req_start); | |
193 | } | |
194 | } | |
195 | ||
196 | out: | |
197 | if (unlikely(verbose_request)) | |
198 | printk(KERN_DEBUG "pciback: %s: read %d bytes at 0x%x = %x\n", | |
199 | pci_name(dev), size, offset, value); | |
200 | ||
201 | *ret_val = value; | |
202 | return pcibios_err_to_errno(err); | |
203 | } | |
204 | ||
205 | int pciback_config_write(struct pci_dev *dev, int offset, int size, u32 value) | |
206 | { | |
207 | int err = 0, handled = 0; | |
208 | struct pciback_dev_data *dev_data = pci_get_drvdata(dev); | |
209 | const struct config_field_entry *cfg_entry; | |
210 | const struct config_field *field; | |
211 | u32 tmp_val; | |
212 | int req_start, req_end, field_start, field_end; | |
213 | ||
214 | if (unlikely(verbose_request)) | |
215 | printk(KERN_DEBUG | |
216 | "pciback: %s: write request %d bytes at 0x%x = %x\n", | |
217 | pci_name(dev), size, offset, value); | |
218 | ||
219 | if (!valid_request(offset, size)) | |
220 | return XEN_PCI_ERR_invalid_offset; | |
221 | ||
222 | list_for_each_entry(cfg_entry, &dev_data->config_fields, list) { | |
223 | field = cfg_entry->field; | |
224 | ||
225 | req_start = offset; | |
226 | req_end = offset + size; | |
227 | field_start = OFFSET(cfg_entry); | |
228 | field_end = OFFSET(cfg_entry) + field->size; | |
229 | ||
230 | if ((req_start >= field_start && req_start < field_end) | |
231 | || (req_end > field_start && req_end <= field_end)) { | |
232 | tmp_val = 0; | |
233 | ||
234 | err = pciback_config_read(dev, field_start, | |
235 | field->size, &tmp_val); | |
236 | if (err) | |
237 | break; | |
238 | ||
239 | tmp_val = merge_value(tmp_val, value, get_mask(size), | |
240 | req_start - field_start); | |
241 | ||
242 | err = conf_space_write(dev, cfg_entry, field_start, | |
243 | tmp_val); | |
244 | ||
245 | /* handled is set true here, but not every byte | |
246 | * may have been written! Properly detecting if | |
247 | * every byte is handled is unnecessary as the | |
248 | * flag is used to detect devices that need | |
249 | * special helpers to work correctly. | |
250 | */ | |
251 | handled = 1; | |
252 | } | |
253 | } | |
254 | ||
255 | if (!handled && !err) { | |
256 | /* By default, anything not specificially handled above is | |
257 | * read-only. The permissive flag changes this behavior so | |
258 | * that anything not specifically handled above is writable. | |
259 | * This means that some fields may still be read-only because | |
260 | * they have entries in the config_field list that intercept | |
261 | * the write and do nothing. */ | |
262 | if (dev_data->permissive || permissive) { | |
263 | switch (size) { | |
264 | case 1: | |
265 | err = pci_write_config_byte(dev, offset, | |
266 | (u8) value); | |
267 | break; | |
268 | case 2: | |
269 | err = pci_write_config_word(dev, offset, | |
270 | (u16) value); | |
271 | break; | |
272 | case 4: | |
273 | err = pci_write_config_dword(dev, offset, | |
274 | (u32) value); | |
275 | break; | |
276 | } | |
277 | } else if (!dev_data->warned_on_write) { | |
278 | dev_data->warned_on_write = 1; | |
279 | dev_warn(&dev->dev, "Driver tried to write to a " | |
280 | "read-only configuration space field at offset" | |
281 | " 0x%x, size %d. This may be harmless, but if " | |
282 | "you have problems with your device:\n" | |
283 | "1) see permissive attribute in sysfs\n" | |
284 | "2) report problems to the xen-devel " | |
285 | "mailing list along with details of your " | |
286 | "device obtained from lspci.\n", offset, size); | |
287 | } | |
288 | } | |
289 | ||
290 | return pcibios_err_to_errno(err); | |
291 | } | |
292 | ||
293 | void pciback_config_free_dyn_fields(struct pci_dev *dev) | |
294 | { | |
295 | struct pciback_dev_data *dev_data = pci_get_drvdata(dev); | |
296 | struct config_field_entry *cfg_entry, *t; | |
297 | const struct config_field *field; | |
298 | ||
299 | dev_dbg(&dev->dev, "free-ing dynamically allocated virtual " | |
300 | "configuration space fields\n"); | |
301 | if (!dev_data) | |
302 | return; | |
303 | ||
304 | list_for_each_entry_safe(cfg_entry, t, &dev_data->config_fields, list) { | |
305 | field = cfg_entry->field; | |
306 | ||
307 | if (field->clean) { | |
308 | field->clean((struct config_field *)field); | |
309 | ||
310 | kfree(cfg_entry->data); | |
311 | ||
312 | list_del(&cfg_entry->list); | |
313 | kfree(cfg_entry); | |
314 | } | |
315 | ||
316 | } | |
317 | } | |
318 | ||
319 | void pciback_config_reset_dev(struct pci_dev *dev) | |
320 | { | |
321 | struct pciback_dev_data *dev_data = pci_get_drvdata(dev); | |
322 | const struct config_field_entry *cfg_entry; | |
323 | const struct config_field *field; | |
324 | ||
325 | dev_dbg(&dev->dev, "resetting virtual configuration space\n"); | |
326 | if (!dev_data) | |
327 | return; | |
328 | ||
329 | list_for_each_entry(cfg_entry, &dev_data->config_fields, list) { | |
330 | field = cfg_entry->field; | |
331 | ||
332 | if (field->reset) | |
333 | field->reset(dev, OFFSET(cfg_entry), cfg_entry->data); | |
334 | } | |
335 | } | |
336 | ||
337 | void pciback_config_free_dev(struct pci_dev *dev) | |
338 | { | |
339 | struct pciback_dev_data *dev_data = pci_get_drvdata(dev); | |
340 | struct config_field_entry *cfg_entry, *t; | |
341 | const struct config_field *field; | |
342 | ||
343 | dev_dbg(&dev->dev, "free-ing virtual configuration space fields\n"); | |
344 | if (!dev_data) | |
345 | return; | |
346 | ||
347 | list_for_each_entry_safe(cfg_entry, t, &dev_data->config_fields, list) { | |
348 | list_del(&cfg_entry->list); | |
349 | ||
350 | field = cfg_entry->field; | |
351 | ||
352 | if (field->release) | |
353 | field->release(dev, OFFSET(cfg_entry), cfg_entry->data); | |
354 | ||
355 | kfree(cfg_entry); | |
356 | } | |
357 | } | |
358 | ||
359 | int pciback_config_add_field_offset(struct pci_dev *dev, | |
360 | const struct config_field *field, | |
361 | unsigned int base_offset) | |
362 | { | |
363 | int err = 0; | |
364 | struct pciback_dev_data *dev_data = pci_get_drvdata(dev); | |
365 | struct config_field_entry *cfg_entry; | |
366 | void *tmp; | |
367 | ||
368 | cfg_entry = kmalloc(sizeof(*cfg_entry), GFP_KERNEL); | |
369 | if (!cfg_entry) { | |
370 | err = -ENOMEM; | |
371 | goto out; | |
372 | } | |
373 | ||
374 | cfg_entry->data = NULL; | |
375 | cfg_entry->field = field; | |
376 | cfg_entry->base_offset = base_offset; | |
377 | ||
378 | /* silently ignore duplicate fields */ | |
379 | err = pciback_field_is_dup(dev, OFFSET(cfg_entry)); | |
380 | if (err) | |
381 | goto out; | |
382 | ||
383 | if (field->init) { | |
384 | tmp = field->init(dev, OFFSET(cfg_entry)); | |
385 | ||
386 | if (IS_ERR(tmp)) { | |
387 | err = PTR_ERR(tmp); | |
388 | goto out; | |
389 | } | |
390 | ||
391 | cfg_entry->data = tmp; | |
392 | } | |
393 | ||
394 | dev_dbg(&dev->dev, "added config field at offset 0x%02x\n", | |
395 | OFFSET(cfg_entry)); | |
396 | list_add_tail(&cfg_entry->list, &dev_data->config_fields); | |
397 | ||
398 | out: | |
399 | if (err) | |
400 | kfree(cfg_entry); | |
401 | ||
402 | return err; | |
403 | } | |
404 | ||
405 | /* This sets up the device's virtual configuration space to keep track of | |
406 | * certain registers (like the base address registers (BARs) so that we can | |
407 | * keep the client from manipulating them directly. | |
408 | */ | |
409 | int pciback_config_init_dev(struct pci_dev *dev) | |
410 | { | |
411 | int err = 0; | |
412 | struct pciback_dev_data *dev_data = pci_get_drvdata(dev); | |
413 | ||
414 | dev_dbg(&dev->dev, "initializing virtual configuration space\n"); | |
415 | ||
416 | INIT_LIST_HEAD(&dev_data->config_fields); | |
417 | ||
418 | err = pciback_config_header_add_fields(dev); | |
419 | if (err) | |
420 | goto out; | |
421 | ||
422 | err = pciback_config_capability_add_fields(dev); | |
423 | if (err) | |
424 | goto out; | |
425 | ||
426 | err = pciback_config_quirks_init(dev); | |
427 | ||
428 | out: | |
429 | return err; | |
430 | } | |
431 | ||
432 | int pciback_config_init(void) | |
433 | { | |
434 | return pciback_config_capability_init(); | |
435 | } |