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