1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * PCI Express I/O Virtualization (IOV) support
4 * Address Translation Service 1.0
5 * Page Request Interface added by Joerg Roedel <joerg.roedel@amd.com>
6 * PASID support added by Joerg Roedel <joerg.roedel@amd.com>
7 *
8 * Copyright (C) 2009 Intel Corporation, Yu Zhao <yu.zhao@intel.com>
9 * Copyright (C) 2011 Advanced Micro Devices,
10 */
11
12 #include <linux/bitfield.h>
13 #include <linux/export.h>
14 #include <linux/pci-ats.h>
15 #include <linux/pci.h>
16 #include <linux/slab.h>
17
18 #include "pci.h"
19
pci_ats_init(struct pci_dev * dev)20 void pci_ats_init(struct pci_dev *dev)
21 {
22 int pos;
23
24 if (pci_ats_disabled())
25 return;
26
27 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS);
28 if (!pos)
29 return;
30
31 dev->ats_cap = pos;
32 }
33
34 /**
35 * pci_ats_supported - check if the device can use ATS
36 * @dev: the PCI device
37 *
38 * Returns true if the device supports ATS and is allowed to use it, false
39 * otherwise.
40 */
pci_ats_supported(struct pci_dev * dev)41 bool pci_ats_supported(struct pci_dev *dev)
42 {
43 if (!dev->ats_cap)
44 return false;
45
46 return (dev->untrusted == 0);
47 }
48 EXPORT_SYMBOL_GPL(pci_ats_supported);
49
50 /**
51 * pci_prepare_ats - Setup the PS for ATS
52 * @dev: the PCI device
53 * @ps: the IOMMU page shift
54 *
55 * This must be done by the IOMMU driver on the PF before any VFs are created to
56 * ensure that the VF can have ATS enabled.
57 *
58 * Returns 0 on success, or negative on failure.
59 */
pci_prepare_ats(struct pci_dev * dev,int ps)60 int pci_prepare_ats(struct pci_dev *dev, int ps)
61 {
62 u16 ctrl;
63
64 if (!pci_ats_supported(dev))
65 return -EINVAL;
66
67 if (WARN_ON(dev->ats_enabled))
68 return -EBUSY;
69
70 if (ps < PCI_ATS_MIN_STU)
71 return -EINVAL;
72
73 if (dev->is_virtfn)
74 return 0;
75
76 dev->ats_stu = ps;
77 ctrl = PCI_ATS_CTRL_STU(dev->ats_stu - PCI_ATS_MIN_STU);
78 pci_write_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, ctrl);
79 return 0;
80 }
81 EXPORT_SYMBOL_GPL(pci_prepare_ats);
82
83 /**
84 * pci_enable_ats - enable the ATS capability
85 * @dev: the PCI device
86 * @ps: the IOMMU page shift
87 *
88 * Returns 0 on success, or negative on failure.
89 */
pci_enable_ats(struct pci_dev * dev,int ps)90 int pci_enable_ats(struct pci_dev *dev, int ps)
91 {
92 u16 ctrl;
93 struct pci_dev *pdev;
94
95 if (!pci_ats_supported(dev))
96 return -EINVAL;
97
98 if (WARN_ON(dev->ats_enabled))
99 return -EBUSY;
100
101 if (ps < PCI_ATS_MIN_STU)
102 return -EINVAL;
103
104 /*
105 * Note that enabling ATS on a VF fails unless it's already enabled
106 * with the same STU on the PF.
107 */
108 ctrl = PCI_ATS_CTRL_ENABLE;
109 if (dev->is_virtfn) {
110 pdev = pci_physfn(dev);
111 if (pdev->ats_stu != ps)
112 return -EINVAL;
113 } else {
114 dev->ats_stu = ps;
115 ctrl |= PCI_ATS_CTRL_STU(dev->ats_stu - PCI_ATS_MIN_STU);
116 }
117 pci_write_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, ctrl);
118
119 dev->ats_enabled = 1;
120 return 0;
121 }
122 EXPORT_SYMBOL_GPL(pci_enable_ats);
123
124 /**
125 * pci_disable_ats - disable the ATS capability
126 * @dev: the PCI device
127 */
pci_disable_ats(struct pci_dev * dev)128 void pci_disable_ats(struct pci_dev *dev)
129 {
130 u16 ctrl;
131
132 if (WARN_ON(!dev->ats_enabled))
133 return;
134
135 pci_read_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, &ctrl);
136 ctrl &= ~PCI_ATS_CTRL_ENABLE;
137 pci_write_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, ctrl);
138
139 dev->ats_enabled = 0;
140 }
141 EXPORT_SYMBOL_GPL(pci_disable_ats);
142
pci_restore_ats_state(struct pci_dev * dev)143 void pci_restore_ats_state(struct pci_dev *dev)
144 {
145 u16 ctrl;
146
147 if (!dev->ats_enabled)
148 return;
149
150 ctrl = PCI_ATS_CTRL_ENABLE;
151 if (!dev->is_virtfn)
152 ctrl |= PCI_ATS_CTRL_STU(dev->ats_stu - PCI_ATS_MIN_STU);
153 pci_write_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, ctrl);
154 }
155
156 /**
157 * pci_ats_queue_depth - query the ATS Invalidate Queue Depth
158 * @dev: the PCI device
159 *
160 * Returns the queue depth on success, or negative on failure.
161 *
162 * The ATS spec uses 0 in the Invalidate Queue Depth field to
163 * indicate that the function can accept 32 Invalidate Request.
164 * But here we use the `real' values (i.e. 1~32) for the Queue
165 * Depth; and 0 indicates the function shares the Queue with
166 * other functions (doesn't exclusively own a Queue).
167 */
pci_ats_queue_depth(struct pci_dev * dev)168 int pci_ats_queue_depth(struct pci_dev *dev)
169 {
170 u16 cap;
171
172 if (!dev->ats_cap)
173 return -EINVAL;
174
175 if (dev->is_virtfn)
176 return 0;
177
178 pci_read_config_word(dev, dev->ats_cap + PCI_ATS_CAP, &cap);
179 return PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) : PCI_ATS_MAX_QDEP;
180 }
181
182 /**
183 * pci_ats_page_aligned - Return Page Aligned Request bit status.
184 * @pdev: the PCI device
185 *
186 * Returns 1, if the Untranslated Addresses generated by the device
187 * are always aligned or 0 otherwise.
188 *
189 * Per PCIe spec r4.0, sec 10.5.1.2, if the Page Aligned Request bit
190 * is set, it indicates the Untranslated Addresses generated by the
191 * device are always aligned to a 4096 byte boundary.
192 */
pci_ats_page_aligned(struct pci_dev * pdev)193 int pci_ats_page_aligned(struct pci_dev *pdev)
194 {
195 u16 cap;
196
197 if (!pdev->ats_cap)
198 return 0;
199
200 pci_read_config_word(pdev, pdev->ats_cap + PCI_ATS_CAP, &cap);
201
202 if (cap & PCI_ATS_CAP_PAGE_ALIGNED)
203 return 1;
204
205 return 0;
206 }
207
208 #ifdef CONFIG_PCI_PRI
pci_pri_init(struct pci_dev * pdev)209 void pci_pri_init(struct pci_dev *pdev)
210 {
211 u16 status;
212
213 pdev->pri_cap = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
214
215 if (!pdev->pri_cap)
216 return;
217
218 pci_read_config_word(pdev, pdev->pri_cap + PCI_PRI_STATUS, &status);
219 if (status & PCI_PRI_STATUS_PASID)
220 pdev->pasid_required = 1;
221 }
222
223 /**
224 * pci_enable_pri - Enable PRI capability
225 * @pdev: PCI device structure
226 * @reqs: outstanding requests
227 *
228 * Returns 0 on success, negative value on error
229 */
pci_enable_pri(struct pci_dev * pdev,u32 reqs)230 int pci_enable_pri(struct pci_dev *pdev, u32 reqs)
231 {
232 u16 control, status;
233 u32 max_requests;
234 int pri = pdev->pri_cap;
235
236 /*
237 * VFs must not implement the PRI Capability. If their PF
238 * implements PRI, it is shared by the VFs, so if the PF PRI is
239 * enabled, it is also enabled for the VF.
240 */
241 if (pdev->is_virtfn) {
242 if (pci_physfn(pdev)->pri_enabled)
243 return 0;
244 return -EINVAL;
245 }
246
247 if (WARN_ON(pdev->pri_enabled))
248 return -EBUSY;
249
250 if (!pri)
251 return -EINVAL;
252
253 pci_read_config_word(pdev, pri + PCI_PRI_STATUS, &status);
254 if (!(status & PCI_PRI_STATUS_STOPPED))
255 return -EBUSY;
256
257 pci_read_config_dword(pdev, pri + PCI_PRI_MAX_REQ, &max_requests);
258 reqs = min(max_requests, reqs);
259 pdev->pri_reqs_alloc = reqs;
260 pci_write_config_dword(pdev, pri + PCI_PRI_ALLOC_REQ, reqs);
261
262 control = PCI_PRI_CTRL_ENABLE;
263 pci_write_config_word(pdev, pri + PCI_PRI_CTRL, control);
264
265 pdev->pri_enabled = 1;
266
267 return 0;
268 }
269
270 /**
271 * pci_disable_pri - Disable PRI capability
272 * @pdev: PCI device structure
273 *
274 * Only clears the enabled-bit, regardless of its former value
275 */
pci_disable_pri(struct pci_dev * pdev)276 void pci_disable_pri(struct pci_dev *pdev)
277 {
278 u16 control;
279 int pri = pdev->pri_cap;
280
281 /* VFs share the PF PRI */
282 if (pdev->is_virtfn)
283 return;
284
285 if (WARN_ON(!pdev->pri_enabled))
286 return;
287
288 if (!pri)
289 return;
290
291 pci_read_config_word(pdev, pri + PCI_PRI_CTRL, &control);
292 control &= ~PCI_PRI_CTRL_ENABLE;
293 pci_write_config_word(pdev, pri + PCI_PRI_CTRL, control);
294
295 pdev->pri_enabled = 0;
296 }
297 EXPORT_SYMBOL_GPL(pci_disable_pri);
298
299 /**
300 * pci_restore_pri_state - Restore PRI
301 * @pdev: PCI device structure
302 */
pci_restore_pri_state(struct pci_dev * pdev)303 void pci_restore_pri_state(struct pci_dev *pdev)
304 {
305 u16 control = PCI_PRI_CTRL_ENABLE;
306 u32 reqs = pdev->pri_reqs_alloc;
307 int pri = pdev->pri_cap;
308
309 if (pdev->is_virtfn)
310 return;
311
312 if (!pdev->pri_enabled)
313 return;
314
315 if (!pri)
316 return;
317
318 pci_write_config_dword(pdev, pri + PCI_PRI_ALLOC_REQ, reqs);
319 pci_write_config_word(pdev, pri + PCI_PRI_CTRL, control);
320 }
321
322 /**
323 * pci_reset_pri - Resets device's PRI state
324 * @pdev: PCI device structure
325 *
326 * The PRI capability must be disabled before this function is called.
327 * Returns 0 on success, negative value on error.
328 */
pci_reset_pri(struct pci_dev * pdev)329 int pci_reset_pri(struct pci_dev *pdev)
330 {
331 u16 control;
332 int pri = pdev->pri_cap;
333
334 if (pdev->is_virtfn)
335 return 0;
336
337 if (WARN_ON(pdev->pri_enabled))
338 return -EBUSY;
339
340 if (!pri)
341 return -EINVAL;
342
343 control = PCI_PRI_CTRL_RESET;
344 pci_write_config_word(pdev, pri + PCI_PRI_CTRL, control);
345
346 return 0;
347 }
348
349 /**
350 * pci_prg_resp_pasid_required - Return PRG Response PASID Required bit
351 * status.
352 * @pdev: PCI device structure
353 *
354 * Returns 1 if PASID is required in PRG Response Message, 0 otherwise.
355 */
pci_prg_resp_pasid_required(struct pci_dev * pdev)356 int pci_prg_resp_pasid_required(struct pci_dev *pdev)
357 {
358 if (pdev->is_virtfn)
359 pdev = pci_physfn(pdev);
360
361 return pdev->pasid_required;
362 }
363
364 /**
365 * pci_pri_supported - Check if PRI is supported.
366 * @pdev: PCI device structure
367 *
368 * Returns true if PRI capability is present, false otherwise.
369 */
pci_pri_supported(struct pci_dev * pdev)370 bool pci_pri_supported(struct pci_dev *pdev)
371 {
372 /* VFs share the PF PRI */
373 if (pci_physfn(pdev)->pri_cap)
374 return true;
375 return false;
376 }
377 EXPORT_SYMBOL_GPL(pci_pri_supported);
378 #endif /* CONFIG_PCI_PRI */
379
380 #ifdef CONFIG_PCI_PASID
pci_pasid_init(struct pci_dev * pdev)381 void pci_pasid_init(struct pci_dev *pdev)
382 {
383 pdev->pasid_cap = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
384 }
385
386 /**
387 * pci_enable_pasid - Enable the PASID capability
388 * @pdev: PCI device structure
389 * @features: Features to enable
390 *
391 * Returns 0 on success, negative value on error. This function checks
392 * whether the features are actually supported by the device and returns
393 * an error if not.
394 */
pci_enable_pasid(struct pci_dev * pdev,int features)395 int pci_enable_pasid(struct pci_dev *pdev, int features)
396 {
397 u16 control, supported;
398 int pasid = pdev->pasid_cap;
399
400 /*
401 * VFs must not implement the PASID Capability, but if a PF
402 * supports PASID, its VFs share the PF PASID configuration.
403 */
404 if (pdev->is_virtfn) {
405 if (pci_physfn(pdev)->pasid_enabled)
406 return 0;
407 return -EINVAL;
408 }
409
410 if (WARN_ON(pdev->pasid_enabled))
411 return -EBUSY;
412
413 if (!pdev->eetlp_prefix_path && !pdev->pasid_no_tlp)
414 return -EINVAL;
415
416 if (!pasid)
417 return -EINVAL;
418
419 if (!pci_acs_path_enabled(pdev, NULL, PCI_ACS_RR | PCI_ACS_UF))
420 return -EINVAL;
421
422 pci_read_config_word(pdev, pasid + PCI_PASID_CAP, &supported);
423 supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV;
424
425 /* User wants to enable anything unsupported? */
426 if ((supported & features) != features)
427 return -EINVAL;
428
429 control = PCI_PASID_CTRL_ENABLE | features;
430 pdev->pasid_features = features;
431
432 pci_write_config_word(pdev, pasid + PCI_PASID_CTRL, control);
433
434 pdev->pasid_enabled = 1;
435
436 return 0;
437 }
438 EXPORT_SYMBOL_GPL(pci_enable_pasid);
439
440 /**
441 * pci_disable_pasid - Disable the PASID capability
442 * @pdev: PCI device structure
443 */
pci_disable_pasid(struct pci_dev * pdev)444 void pci_disable_pasid(struct pci_dev *pdev)
445 {
446 u16 control = 0;
447 int pasid = pdev->pasid_cap;
448
449 /* VFs share the PF PASID configuration */
450 if (pdev->is_virtfn)
451 return;
452
453 if (WARN_ON(!pdev->pasid_enabled))
454 return;
455
456 if (!pasid)
457 return;
458
459 pci_write_config_word(pdev, pasid + PCI_PASID_CTRL, control);
460
461 pdev->pasid_enabled = 0;
462 }
463 EXPORT_SYMBOL_GPL(pci_disable_pasid);
464
465 /**
466 * pci_restore_pasid_state - Restore PASID capabilities
467 * @pdev: PCI device structure
468 */
pci_restore_pasid_state(struct pci_dev * pdev)469 void pci_restore_pasid_state(struct pci_dev *pdev)
470 {
471 u16 control;
472 int pasid = pdev->pasid_cap;
473
474 if (pdev->is_virtfn)
475 return;
476
477 if (!pdev->pasid_enabled)
478 return;
479
480 if (!pasid)
481 return;
482
483 control = PCI_PASID_CTRL_ENABLE | pdev->pasid_features;
484 pci_write_config_word(pdev, pasid + PCI_PASID_CTRL, control);
485 }
486
487 /**
488 * pci_pasid_features - Check which PASID features are supported
489 * @pdev: PCI device structure
490 *
491 * Return a negative value when no PASID capability is present.
492 * Otherwise return a bitmask with supported features. Current
493 * features reported are:
494 * PCI_PASID_CAP_EXEC - Execute permission supported
495 * PCI_PASID_CAP_PRIV - Privileged mode supported
496 */
pci_pasid_features(struct pci_dev * pdev)497 int pci_pasid_features(struct pci_dev *pdev)
498 {
499 u16 supported;
500 int pasid;
501
502 if (pdev->is_virtfn)
503 pdev = pci_physfn(pdev);
504
505 pasid = pdev->pasid_cap;
506 if (!pasid)
507 return -EINVAL;
508
509 pci_read_config_word(pdev, pasid + PCI_PASID_CAP, &supported);
510
511 supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV;
512
513 return supported;
514 }
515 EXPORT_SYMBOL_GPL(pci_pasid_features);
516
517 /**
518 * pci_max_pasids - Get maximum number of PASIDs supported by device
519 * @pdev: PCI device structure
520 *
521 * Returns negative value when PASID capability is not present.
522 * Otherwise it returns the number of supported PASIDs.
523 */
pci_max_pasids(struct pci_dev * pdev)524 int pci_max_pasids(struct pci_dev *pdev)
525 {
526 u16 supported;
527 int pasid;
528
529 if (pdev->is_virtfn)
530 pdev = pci_physfn(pdev);
531
532 pasid = pdev->pasid_cap;
533 if (!pasid)
534 return -EINVAL;
535
536 pci_read_config_word(pdev, pasid + PCI_PASID_CAP, &supported);
537
538 return (1 << FIELD_GET(PCI_PASID_CAP_WIDTH, supported));
539 }
540 EXPORT_SYMBOL_GPL(pci_max_pasids);
541 #endif /* CONFIG_PCI_PASID */
542