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8a94ade4 DW |
1 | /* |
2 | * Copyright © 2015 Intel Corporation. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify it | |
5 | * under the terms and conditions of the GNU General Public License, | |
6 | * version 2, as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope it will be useful, but WITHOUT | |
9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
11 | * more details. | |
12 | * | |
13 | * Authors: David Woodhouse <dwmw2@infradead.org> | |
14 | */ | |
15 | ||
16 | #include <linux/intel-iommu.h> | |
2f26e0a9 DW |
17 | #include <linux/mmu_notifier.h> |
18 | #include <linux/sched.h> | |
6e84f315 | 19 | #include <linux/sched/mm.h> |
2f26e0a9 DW |
20 | #include <linux/slab.h> |
21 | #include <linux/intel-svm.h> | |
22 | #include <linux/rculist.h> | |
23 | #include <linux/pci.h> | |
24 | #include <linux/pci-ats.h> | |
a222a7f0 DW |
25 | #include <linux/dmar.h> |
26 | #include <linux/interrupt.h> | |
27 | ||
28 | static irqreturn_t prq_event_thread(int irq, void *d); | |
2f26e0a9 DW |
29 | |
30 | struct pasid_entry { | |
31 | u64 val; | |
32 | }; | |
8a94ade4 | 33 | |
907fea34 DW |
34 | struct pasid_state_entry { |
35 | u64 val; | |
36 | }; | |
37 | ||
8a94ade4 DW |
38 | int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu) |
39 | { | |
40 | struct page *pages; | |
41 | int order; | |
42 | ||
91017044 DW |
43 | /* Start at 2 because it's defined as 2^(1+PSS) */ |
44 | iommu->pasid_max = 2 << ecap_pss(iommu->ecap); | |
45 | ||
46 | /* Eventually I'm promised we will get a multi-level PASID table | |
47 | * and it won't have to be physically contiguous. Until then, | |
48 | * limit the size because 8MiB contiguous allocations can be hard | |
49 | * to come by. The limit of 0x20000, which is 1MiB for each of | |
50 | * the PASID and PASID-state tables, is somewhat arbitrary. */ | |
51 | if (iommu->pasid_max > 0x20000) | |
52 | iommu->pasid_max = 0x20000; | |
53 | ||
54 | order = get_order(sizeof(struct pasid_entry) * iommu->pasid_max); | |
8a94ade4 DW |
55 | pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, order); |
56 | if (!pages) { | |
57 | pr_warn("IOMMU: %s: Failed to allocate PASID table\n", | |
58 | iommu->name); | |
59 | return -ENOMEM; | |
60 | } | |
61 | iommu->pasid_table = page_address(pages); | |
62 | pr_info("%s: Allocated order %d PASID table.\n", iommu->name, order); | |
63 | ||
64 | if (ecap_dis(iommu->ecap)) { | |
91017044 DW |
65 | /* Just making it explicit... */ |
66 | BUILD_BUG_ON(sizeof(struct pasid_entry) != sizeof(struct pasid_state_entry)); | |
8a94ade4 DW |
67 | pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, order); |
68 | if (pages) | |
69 | iommu->pasid_state_table = page_address(pages); | |
70 | else | |
71 | pr_warn("IOMMU: %s: Failed to allocate PASID state table\n", | |
72 | iommu->name); | |
73 | } | |
74 | ||
2f26e0a9 DW |
75 | idr_init(&iommu->pasid_idr); |
76 | ||
8a94ade4 DW |
77 | return 0; |
78 | } | |
79 | ||
80 | int intel_svm_free_pasid_tables(struct intel_iommu *iommu) | |
81 | { | |
91017044 | 82 | int order = get_order(sizeof(struct pasid_entry) * iommu->pasid_max); |
8a94ade4 DW |
83 | |
84 | if (iommu->pasid_table) { | |
85 | free_pages((unsigned long)iommu->pasid_table, order); | |
86 | iommu->pasid_table = NULL; | |
87 | } | |
88 | if (iommu->pasid_state_table) { | |
89 | free_pages((unsigned long)iommu->pasid_state_table, order); | |
90 | iommu->pasid_state_table = NULL; | |
91 | } | |
2f26e0a9 | 92 | idr_destroy(&iommu->pasid_idr); |
8a94ade4 DW |
93 | return 0; |
94 | } | |
2f26e0a9 | 95 | |
a222a7f0 DW |
96 | #define PRQ_ORDER 0 |
97 | ||
98 | int intel_svm_enable_prq(struct intel_iommu *iommu) | |
99 | { | |
100 | struct page *pages; | |
101 | int irq, ret; | |
102 | ||
103 | pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, PRQ_ORDER); | |
104 | if (!pages) { | |
105 | pr_warn("IOMMU: %s: Failed to allocate page request queue\n", | |
106 | iommu->name); | |
107 | return -ENOMEM; | |
108 | } | |
109 | iommu->prq = page_address(pages); | |
110 | ||
111 | irq = dmar_alloc_hwirq(DMAR_UNITS_SUPPORTED + iommu->seq_id, iommu->node, iommu); | |
112 | if (irq <= 0) { | |
113 | pr_err("IOMMU: %s: Failed to create IRQ vector for page request queue\n", | |
114 | iommu->name); | |
115 | ret = -EINVAL; | |
116 | err: | |
117 | free_pages((unsigned long)iommu->prq, PRQ_ORDER); | |
118 | iommu->prq = NULL; | |
119 | return ret; | |
120 | } | |
121 | iommu->pr_irq = irq; | |
122 | ||
123 | snprintf(iommu->prq_name, sizeof(iommu->prq_name), "dmar%d-prq", iommu->seq_id); | |
124 | ||
125 | ret = request_threaded_irq(irq, NULL, prq_event_thread, IRQF_ONESHOT, | |
126 | iommu->prq_name, iommu); | |
127 | if (ret) { | |
128 | pr_err("IOMMU: %s: Failed to request IRQ for page request queue\n", | |
129 | iommu->name); | |
130 | dmar_free_hwirq(irq); | |
131 | goto err; | |
132 | } | |
133 | dmar_writeq(iommu->reg + DMAR_PQH_REG, 0ULL); | |
134 | dmar_writeq(iommu->reg + DMAR_PQT_REG, 0ULL); | |
135 | dmar_writeq(iommu->reg + DMAR_PQA_REG, virt_to_phys(iommu->prq) | PRQ_ORDER); | |
136 | ||
137 | return 0; | |
138 | } | |
139 | ||
140 | int intel_svm_finish_prq(struct intel_iommu *iommu) | |
141 | { | |
142 | dmar_writeq(iommu->reg + DMAR_PQH_REG, 0ULL); | |
143 | dmar_writeq(iommu->reg + DMAR_PQT_REG, 0ULL); | |
144 | dmar_writeq(iommu->reg + DMAR_PQA_REG, 0ULL); | |
145 | ||
146 | free_irq(iommu->pr_irq, iommu); | |
147 | dmar_free_hwirq(iommu->pr_irq); | |
148 | iommu->pr_irq = 0; | |
149 | ||
150 | free_pages((unsigned long)iommu->prq, PRQ_ORDER); | |
151 | iommu->prq = NULL; | |
152 | ||
153 | return 0; | |
154 | } | |
155 | ||
2f26e0a9 | 156 | static void intel_flush_svm_range_dev (struct intel_svm *svm, struct intel_svm_dev *sdev, |
5d52f482 | 157 | unsigned long address, unsigned long pages, int ih, int gl) |
2f26e0a9 DW |
158 | { |
159 | struct qi_desc desc; | |
2f26e0a9 | 160 | |
5d52f482 | 161 | if (pages == -1) { |
e0349921 DW |
162 | /* For global kernel pages we have to flush them in *all* PASIDs |
163 | * because that's the only option the hardware gives us. Despite | |
164 | * the fact that they are actually only accessible through one. */ | |
165 | if (gl) | |
166 | desc.low = QI_EIOTLB_PASID(svm->pasid) | QI_EIOTLB_DID(sdev->did) | | |
167 | QI_EIOTLB_GRAN(QI_GRAN_ALL_ALL) | QI_EIOTLB_TYPE; | |
168 | else | |
169 | desc.low = QI_EIOTLB_PASID(svm->pasid) | QI_EIOTLB_DID(sdev->did) | | |
170 | QI_EIOTLB_GRAN(QI_GRAN_NONG_PASID) | QI_EIOTLB_TYPE; | |
2f26e0a9 DW |
171 | desc.high = 0; |
172 | } else { | |
5d52f482 DW |
173 | int mask = ilog2(__roundup_pow_of_two(pages)); |
174 | ||
2f26e0a9 DW |
175 | desc.low = QI_EIOTLB_PASID(svm->pasid) | QI_EIOTLB_DID(sdev->did) | |
176 | QI_EIOTLB_GRAN(QI_GRAN_PSI_PASID) | QI_EIOTLB_TYPE; | |
e0349921 | 177 | desc.high = QI_EIOTLB_ADDR(address) | QI_EIOTLB_GL(gl) | |
2f26e0a9 DW |
178 | QI_EIOTLB_IH(ih) | QI_EIOTLB_AM(mask); |
179 | } | |
2f26e0a9 DW |
180 | qi_submit_sync(&desc, svm->iommu); |
181 | ||
182 | if (sdev->dev_iotlb) { | |
183 | desc.low = QI_DEV_EIOTLB_PASID(svm->pasid) | QI_DEV_EIOTLB_SID(sdev->sid) | | |
184 | QI_DEV_EIOTLB_QDEP(sdev->qdep) | QI_DEIOTLB_TYPE; | |
5d52f482 DW |
185 | if (pages == -1) { |
186 | desc.high = QI_DEV_EIOTLB_ADDR(-1ULL >> 1) | QI_DEV_EIOTLB_SIZE; | |
187 | } else if (pages > 1) { | |
188 | /* The least significant zero bit indicates the size. So, | |
189 | * for example, an "address" value of 0x12345f000 will | |
190 | * flush from 0x123440000 to 0x12347ffff (256KiB). */ | |
191 | unsigned long last = address + ((unsigned long)(pages - 1) << VTD_PAGE_SHIFT); | |
192 | unsigned long mask = __rounddown_pow_of_two(address ^ last);; | |
193 | ||
194 | desc.high = QI_DEV_EIOTLB_ADDR((address & ~mask) | (mask - 1)) | QI_DEV_EIOTLB_SIZE; | |
2f26e0a9 DW |
195 | } else { |
196 | desc.high = QI_DEV_EIOTLB_ADDR(address); | |
197 | } | |
198 | qi_submit_sync(&desc, svm->iommu); | |
199 | } | |
200 | } | |
201 | ||
202 | static void intel_flush_svm_range(struct intel_svm *svm, unsigned long address, | |
5d52f482 | 203 | unsigned long pages, int ih, int gl) |
2f26e0a9 DW |
204 | { |
205 | struct intel_svm_dev *sdev; | |
206 | ||
907fea34 DW |
207 | /* Try deferred invalidate if available */ |
208 | if (svm->iommu->pasid_state_table && | |
209 | !cmpxchg64(&svm->iommu->pasid_state_table[svm->pasid].val, 0, 1ULL << 63)) | |
210 | return; | |
211 | ||
2f26e0a9 DW |
212 | rcu_read_lock(); |
213 | list_for_each_entry_rcu(sdev, &svm->devs, list) | |
e0349921 | 214 | intel_flush_svm_range_dev(svm, sdev, address, pages, ih, gl); |
2f26e0a9 DW |
215 | rcu_read_unlock(); |
216 | } | |
217 | ||
218 | static void intel_change_pte(struct mmu_notifier *mn, struct mm_struct *mm, | |
219 | unsigned long address, pte_t pte) | |
220 | { | |
221 | struct intel_svm *svm = container_of(mn, struct intel_svm, notifier); | |
222 | ||
e0349921 | 223 | intel_flush_svm_range(svm, address, 1, 1, 0); |
2f26e0a9 DW |
224 | } |
225 | ||
2f26e0a9 DW |
226 | /* Pages have been freed at this point */ |
227 | static void intel_invalidate_range(struct mmu_notifier *mn, | |
228 | struct mm_struct *mm, | |
229 | unsigned long start, unsigned long end) | |
230 | { | |
231 | struct intel_svm *svm = container_of(mn, struct intel_svm, notifier); | |
232 | ||
233 | intel_flush_svm_range(svm, start, | |
e0349921 | 234 | (end - start + PAGE_SIZE - 1) >> VTD_PAGE_SHIFT, 0, 0); |
2f26e0a9 DW |
235 | } |
236 | ||
237 | ||
5a10ba27 | 238 | static void intel_flush_pasid_dev(struct intel_svm *svm, struct intel_svm_dev *sdev, int pasid) |
2f26e0a9 DW |
239 | { |
240 | struct qi_desc desc; | |
241 | ||
242 | desc.high = 0; | |
5a10ba27 | 243 | desc.low = QI_PC_TYPE | QI_PC_DID(sdev->did) | QI_PC_PASID_SEL | QI_PC_PASID(pasid); |
2f26e0a9 DW |
244 | |
245 | qi_submit_sync(&desc, svm->iommu); | |
246 | } | |
247 | ||
248 | static void intel_mm_release(struct mmu_notifier *mn, struct mm_struct *mm) | |
249 | { | |
250 | struct intel_svm *svm = container_of(mn, struct intel_svm, notifier); | |
e57e58bd | 251 | struct intel_svm_dev *sdev; |
2f26e0a9 | 252 | |
e57e58bd DW |
253 | /* This might end up being called from exit_mmap(), *before* the page |
254 | * tables are cleared. And __mmu_notifier_release() will delete us from | |
255 | * the list of notifiers so that our invalidate_range() callback doesn't | |
256 | * get called when the page tables are cleared. So we need to protect | |
257 | * against hardware accessing those page tables. | |
258 | * | |
259 | * We do it by clearing the entry in the PASID table and then flushing | |
260 | * the IOTLB and the PASID table caches. This might upset hardware; | |
261 | * perhaps we'll want to point the PASID to a dummy PGD (like the zero | |
262 | * page) so that we end up taking a fault that the hardware really | |
263 | * *has* to handle gracefully without affecting other processes. | |
264 | */ | |
2f26e0a9 | 265 | svm->iommu->pasid_table[svm->pasid].val = 0; |
e57e58bd DW |
266 | wmb(); |
267 | ||
268 | rcu_read_lock(); | |
269 | list_for_each_entry_rcu(sdev, &svm->devs, list) { | |
270 | intel_flush_pasid_dev(svm, sdev, svm->pasid); | |
271 | intel_flush_svm_range_dev(svm, sdev, 0, -1, 0, !svm->mm); | |
272 | } | |
273 | rcu_read_unlock(); | |
2f26e0a9 | 274 | |
2f26e0a9 DW |
275 | } |
276 | ||
277 | static const struct mmu_notifier_ops intel_mmuops = { | |
278 | .release = intel_mm_release, | |
279 | .change_pte = intel_change_pte, | |
2f26e0a9 DW |
280 | .invalidate_range = intel_invalidate_range, |
281 | }; | |
282 | ||
283 | static DEFINE_MUTEX(pasid_mutex); | |
284 | ||
0204a496 | 285 | int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_ops *ops) |
2f26e0a9 DW |
286 | { |
287 | struct intel_iommu *iommu = intel_svm_device_to_iommu(dev); | |
288 | struct intel_svm_dev *sdev; | |
289 | struct intel_svm *svm = NULL; | |
5cec7537 | 290 | struct mm_struct *mm = NULL; |
2f26e0a9 DW |
291 | int pasid_max; |
292 | int ret; | |
293 | ||
2f26e0a9 DW |
294 | if (WARN_ON(!iommu)) |
295 | return -EINVAL; | |
296 | ||
297 | if (dev_is_pci(dev)) { | |
298 | pasid_max = pci_max_pasids(to_pci_dev(dev)); | |
299 | if (pasid_max < 0) | |
300 | return -EINVAL; | |
301 | } else | |
302 | pasid_max = 1 << 20; | |
303 | ||
5cec7537 DW |
304 | if ((flags & SVM_FLAG_SUPERVISOR_MODE)) { |
305 | if (!ecap_srs(iommu->ecap)) | |
306 | return -EINVAL; | |
307 | } else if (pasid) { | |
308 | mm = get_task_mm(current); | |
309 | BUG_ON(!mm); | |
310 | } | |
311 | ||
2f26e0a9 | 312 | mutex_lock(&pasid_mutex); |
569e4f77 | 313 | if (pasid && !(flags & SVM_FLAG_PRIVATE_PASID)) { |
2f26e0a9 DW |
314 | int i; |
315 | ||
316 | idr_for_each_entry(&iommu->pasid_idr, svm, i) { | |
5cec7537 | 317 | if (svm->mm != mm || |
569e4f77 | 318 | (svm->flags & SVM_FLAG_PRIVATE_PASID)) |
2f26e0a9 DW |
319 | continue; |
320 | ||
321 | if (svm->pasid >= pasid_max) { | |
322 | dev_warn(dev, | |
323 | "Limited PASID width. Cannot use existing PASID %d\n", | |
324 | svm->pasid); | |
325 | ret = -ENOSPC; | |
326 | goto out; | |
327 | } | |
328 | ||
329 | list_for_each_entry(sdev, &svm->devs, list) { | |
330 | if (dev == sdev->dev) { | |
0204a496 DW |
331 | if (sdev->ops != ops) { |
332 | ret = -EBUSY; | |
333 | goto out; | |
334 | } | |
2f26e0a9 DW |
335 | sdev->users++; |
336 | goto success; | |
337 | } | |
338 | } | |
339 | ||
340 | break; | |
341 | } | |
342 | } | |
343 | ||
344 | sdev = kzalloc(sizeof(*sdev), GFP_KERNEL); | |
345 | if (!sdev) { | |
346 | ret = -ENOMEM; | |
347 | goto out; | |
348 | } | |
349 | sdev->dev = dev; | |
350 | ||
351 | ret = intel_iommu_enable_pasid(iommu, sdev); | |
352 | if (ret || !pasid) { | |
353 | /* If they don't actually want to assign a PASID, this is | |
354 | * just an enabling check/preparation. */ | |
355 | kfree(sdev); | |
356 | goto out; | |
357 | } | |
358 | /* Finish the setup now we know we're keeping it */ | |
359 | sdev->users = 1; | |
0204a496 | 360 | sdev->ops = ops; |
2f26e0a9 DW |
361 | init_rcu_head(&sdev->rcu); |
362 | ||
363 | if (!svm) { | |
364 | svm = kzalloc(sizeof(*svm), GFP_KERNEL); | |
365 | if (!svm) { | |
366 | ret = -ENOMEM; | |
367 | kfree(sdev); | |
368 | goto out; | |
369 | } | |
370 | svm->iommu = iommu; | |
371 | ||
91017044 DW |
372 | if (pasid_max > iommu->pasid_max) |
373 | pasid_max = iommu->pasid_max; | |
2f26e0a9 | 374 | |
5a10ba27 DW |
375 | /* Do not use PASID 0 in caching mode (virtualised IOMMU) */ |
376 | ret = idr_alloc(&iommu->pasid_idr, svm, | |
377 | !!cap_caching_mode(iommu->cap), | |
378 | pasid_max - 1, GFP_KERNEL); | |
2f26e0a9 DW |
379 | if (ret < 0) { |
380 | kfree(svm); | |
381 | goto out; | |
382 | } | |
383 | svm->pasid = ret; | |
384 | svm->notifier.ops = &intel_mmuops; | |
5cec7537 | 385 | svm->mm = mm; |
569e4f77 | 386 | svm->flags = flags; |
2f26e0a9 DW |
387 | INIT_LIST_HEAD_RCU(&svm->devs); |
388 | ret = -ENOMEM; | |
5cec7537 DW |
389 | if (mm) { |
390 | ret = mmu_notifier_register(&svm->notifier, mm); | |
391 | if (ret) { | |
392 | idr_remove(&svm->iommu->pasid_idr, svm->pasid); | |
393 | kfree(svm); | |
394 | kfree(sdev); | |
395 | goto out; | |
396 | } | |
397 | iommu->pasid_table[svm->pasid].val = (u64)__pa(mm->pgd) | 1; | |
5cec7537 DW |
398 | } else |
399 | iommu->pasid_table[svm->pasid].val = (u64)__pa(init_mm.pgd) | 1 | (1ULL << 11); | |
2f26e0a9 | 400 | wmb(); |
5a10ba27 DW |
401 | /* In caching mode, we still have to flush with PASID 0 when |
402 | * a PASID table entry becomes present. Not entirely clear | |
403 | * *why* that would be the case — surely we could just issue | |
404 | * a flush with the PASID value that we've changed? The PASID | |
405 | * is the index into the table, after all. It's not like domain | |
406 | * IDs in the case of the equivalent context-entry change in | |
407 | * caching mode. And for that matter it's not entirely clear why | |
408 | * a VMM would be in the business of caching the PASID table | |
409 | * anyway. Surely that can be left entirely to the guest? */ | |
410 | if (cap_caching_mode(iommu->cap)) | |
411 | intel_flush_pasid_dev(svm, sdev, 0); | |
2f26e0a9 DW |
412 | } |
413 | list_add_rcu(&sdev->list, &svm->devs); | |
414 | ||
415 | success: | |
416 | *pasid = svm->pasid; | |
417 | ret = 0; | |
418 | out: | |
419 | mutex_unlock(&pasid_mutex); | |
5cec7537 DW |
420 | if (mm) |
421 | mmput(mm); | |
2f26e0a9 DW |
422 | return ret; |
423 | } | |
424 | EXPORT_SYMBOL_GPL(intel_svm_bind_mm); | |
425 | ||
426 | int intel_svm_unbind_mm(struct device *dev, int pasid) | |
427 | { | |
428 | struct intel_svm_dev *sdev; | |
429 | struct intel_iommu *iommu; | |
430 | struct intel_svm *svm; | |
431 | int ret = -EINVAL; | |
432 | ||
433 | mutex_lock(&pasid_mutex); | |
434 | iommu = intel_svm_device_to_iommu(dev); | |
435 | if (!iommu || !iommu->pasid_table) | |
436 | goto out; | |
437 | ||
438 | svm = idr_find(&iommu->pasid_idr, pasid); | |
439 | if (!svm) | |
440 | goto out; | |
441 | ||
442 | list_for_each_entry(sdev, &svm->devs, list) { | |
443 | if (dev == sdev->dev) { | |
444 | ret = 0; | |
445 | sdev->users--; | |
446 | if (!sdev->users) { | |
447 | list_del_rcu(&sdev->list); | |
448 | /* Flush the PASID cache and IOTLB for this device. | |
449 | * Note that we do depend on the hardware *not* using | |
450 | * the PASID any more. Just as we depend on other | |
451 | * devices never using PASIDs that they have no right | |
452 | * to use. We have a *shared* PASID table, because it's | |
453 | * large and has to be physically contiguous. So it's | |
454 | * hard to be as defensive as we might like. */ | |
5a10ba27 | 455 | intel_flush_pasid_dev(svm, sdev, svm->pasid); |
e0349921 | 456 | intel_flush_svm_range_dev(svm, sdev, 0, -1, 0, !svm->mm); |
2f26e0a9 DW |
457 | kfree_rcu(sdev, rcu); |
458 | ||
459 | if (list_empty(&svm->devs)) { | |
2f26e0a9 DW |
460 | |
461 | idr_remove(&svm->iommu->pasid_idr, svm->pasid); | |
5cec7537 | 462 | if (svm->mm) |
e57e58bd DW |
463 | mmu_notifier_unregister(&svm->notifier, svm->mm); |
464 | ||
2f26e0a9 DW |
465 | /* We mandate that no page faults may be outstanding |
466 | * for the PASID when intel_svm_unbind_mm() is called. | |
467 | * If that is not obeyed, subtle errors will happen. | |
468 | * Let's make them less subtle... */ | |
469 | memset(svm, 0x6b, sizeof(*svm)); | |
470 | kfree(svm); | |
471 | } | |
472 | } | |
473 | break; | |
474 | } | |
475 | } | |
476 | out: | |
477 | mutex_unlock(&pasid_mutex); | |
478 | ||
479 | return ret; | |
480 | } | |
481 | EXPORT_SYMBOL_GPL(intel_svm_unbind_mm); | |
a222a7f0 | 482 | |
15060aba CT |
483 | int intel_svm_is_pasid_valid(struct device *dev, int pasid) |
484 | { | |
485 | struct intel_iommu *iommu; | |
486 | struct intel_svm *svm; | |
487 | int ret = -EINVAL; | |
488 | ||
489 | mutex_lock(&pasid_mutex); | |
490 | iommu = intel_svm_device_to_iommu(dev); | |
491 | if (!iommu || !iommu->pasid_table) | |
492 | goto out; | |
493 | ||
494 | svm = idr_find(&iommu->pasid_idr, pasid); | |
495 | if (!svm) | |
496 | goto out; | |
497 | ||
498 | /* init_mm is used in this case */ | |
499 | if (!svm->mm) | |
500 | ret = 1; | |
501 | else if (atomic_read(&svm->mm->mm_users) > 0) | |
502 | ret = 1; | |
503 | else | |
504 | ret = 0; | |
505 | ||
506 | out: | |
507 | mutex_unlock(&pasid_mutex); | |
508 | ||
509 | return ret; | |
510 | } | |
511 | EXPORT_SYMBOL_GPL(intel_svm_is_pasid_valid); | |
512 | ||
a222a7f0 DW |
513 | /* Page request queue descriptor */ |
514 | struct page_req_dsc { | |
515 | u64 srr:1; | |
516 | u64 bof:1; | |
517 | u64 pasid_present:1; | |
518 | u64 lpig:1; | |
519 | u64 pasid:20; | |
520 | u64 bus:8; | |
521 | u64 private:23; | |
522 | u64 prg_index:9; | |
523 | u64 rd_req:1; | |
524 | u64 wr_req:1; | |
525 | u64 exe_req:1; | |
526 | u64 priv_req:1; | |
527 | u64 devfn:8; | |
528 | u64 addr:52; | |
529 | }; | |
530 | ||
531 | #define PRQ_RING_MASK ((0x1000 << PRQ_ORDER) - 0x10) | |
7f8312a3 JR |
532 | |
533 | static bool access_error(struct vm_area_struct *vma, struct page_req_dsc *req) | |
534 | { | |
535 | unsigned long requested = 0; | |
536 | ||
537 | if (req->exe_req) | |
538 | requested |= VM_EXEC; | |
539 | ||
540 | if (req->rd_req) | |
541 | requested |= VM_READ; | |
542 | ||
543 | if (req->wr_req) | |
544 | requested |= VM_WRITE; | |
545 | ||
546 | return (requested & ~vma->vm_flags) != 0; | |
547 | } | |
548 | ||
a222a7f0 DW |
549 | static irqreturn_t prq_event_thread(int irq, void *d) |
550 | { | |
551 | struct intel_iommu *iommu = d; | |
552 | struct intel_svm *svm = NULL; | |
553 | int head, tail, handled = 0; | |
554 | ||
46924008 DW |
555 | /* Clear PPR bit before reading head/tail registers, to |
556 | * ensure that we get a new interrupt if needed. */ | |
557 | writel(DMA_PRS_PPR, iommu->reg + DMAR_PRS_REG); | |
558 | ||
a222a7f0 DW |
559 | tail = dmar_readq(iommu->reg + DMAR_PQT_REG) & PRQ_RING_MASK; |
560 | head = dmar_readq(iommu->reg + DMAR_PQH_REG) & PRQ_RING_MASK; | |
561 | while (head != tail) { | |
0204a496 | 562 | struct intel_svm_dev *sdev; |
a222a7f0 DW |
563 | struct vm_area_struct *vma; |
564 | struct page_req_dsc *req; | |
565 | struct qi_desc resp; | |
566 | int ret, result; | |
567 | u64 address; | |
568 | ||
569 | handled = 1; | |
570 | ||
571 | req = &iommu->prq[head / sizeof(*req)]; | |
572 | ||
573 | result = QI_RESP_FAILURE; | |
7f92a2e9 | 574 | address = (u64)req->addr << VTD_PAGE_SHIFT; |
a222a7f0 DW |
575 | if (!req->pasid_present) { |
576 | pr_err("%s: Page request without PASID: %08llx %08llx\n", | |
577 | iommu->name, ((unsigned long long *)req)[0], | |
578 | ((unsigned long long *)req)[1]); | |
579 | goto bad_req; | |
580 | } | |
581 | ||
582 | if (!svm || svm->pasid != req->pasid) { | |
583 | rcu_read_lock(); | |
584 | svm = idr_find(&iommu->pasid_idr, req->pasid); | |
585 | /* It *can't* go away, because the driver is not permitted | |
586 | * to unbind the mm while any page faults are outstanding. | |
587 | * So we only need RCU to protect the internal idr code. */ | |
588 | rcu_read_unlock(); | |
589 | ||
590 | if (!svm) { | |
591 | pr_err("%s: Page request for invalid PASID %d: %08llx %08llx\n", | |
592 | iommu->name, req->pasid, ((unsigned long long *)req)[0], | |
593 | ((unsigned long long *)req)[1]); | |
26322ab5 | 594 | goto no_pasid; |
a222a7f0 DW |
595 | } |
596 | } | |
597 | ||
598 | result = QI_RESP_INVALID; | |
5cec7537 DW |
599 | /* Since we're using init_mm.pgd directly, we should never take |
600 | * any faults on kernel addresses. */ | |
601 | if (!svm->mm) | |
602 | goto bad_req; | |
e57e58bd | 603 | /* If the mm is already defunct, don't handle faults. */ |
388f7934 | 604 | if (!mmget_not_zero(svm->mm)) |
e57e58bd | 605 | goto bad_req; |
a222a7f0 DW |
606 | down_read(&svm->mm->mmap_sem); |
607 | vma = find_extend_vma(svm->mm, address); | |
608 | if (!vma || address < vma->vm_start) | |
609 | goto invalid; | |
610 | ||
7f8312a3 JR |
611 | if (access_error(vma, req)) |
612 | goto invalid; | |
613 | ||
dcddffd4 | 614 | ret = handle_mm_fault(vma, address, |
a222a7f0 DW |
615 | req->wr_req ? FAULT_FLAG_WRITE : 0); |
616 | if (ret & VM_FAULT_ERROR) | |
617 | goto invalid; | |
618 | ||
619 | result = QI_RESP_SUCCESS; | |
620 | invalid: | |
621 | up_read(&svm->mm->mmap_sem); | |
e57e58bd | 622 | mmput(svm->mm); |
a222a7f0 DW |
623 | bad_req: |
624 | /* Accounting for major/minor faults? */ | |
0204a496 DW |
625 | rcu_read_lock(); |
626 | list_for_each_entry_rcu(sdev, &svm->devs, list) { | |
3c7c2f32 | 627 | if (sdev->sid == PCI_DEVID(req->bus, req->devfn)) |
0204a496 DW |
628 | break; |
629 | } | |
630 | /* Other devices can go away, but the drivers are not permitted | |
631 | * to unbind while any page faults might be in flight. So it's | |
632 | * OK to drop the 'lock' here now we have it. */ | |
633 | rcu_read_unlock(); | |
634 | ||
635 | if (WARN_ON(&sdev->list == &svm->devs)) | |
636 | sdev = NULL; | |
637 | ||
638 | if (sdev && sdev->ops && sdev->ops->fault_cb) { | |
639 | int rwxp = (req->rd_req << 3) | (req->wr_req << 2) | | |
0bdec95c | 640 | (req->exe_req << 1) | (req->priv_req); |
0204a496 DW |
641 | sdev->ops->fault_cb(sdev->dev, req->pasid, req->addr, req->private, rwxp, result); |
642 | } | |
26322ab5 DW |
643 | /* We get here in the error case where the PASID lookup failed, |
644 | and these can be NULL. Do not use them below this point! */ | |
645 | sdev = NULL; | |
646 | svm = NULL; | |
647 | no_pasid: | |
a222a7f0 DW |
648 | if (req->lpig) { |
649 | /* Page Group Response */ | |
650 | resp.low = QI_PGRP_PASID(req->pasid) | | |
651 | QI_PGRP_DID((req->bus << 8) | req->devfn) | | |
652 | QI_PGRP_PASID_P(req->pasid_present) | | |
653 | QI_PGRP_RESP_TYPE; | |
654 | resp.high = QI_PGRP_IDX(req->prg_index) | | |
655 | QI_PGRP_PRIV(req->private) | QI_PGRP_RESP_CODE(result); | |
656 | ||
26322ab5 | 657 | qi_submit_sync(&resp, iommu); |
a222a7f0 DW |
658 | } else if (req->srr) { |
659 | /* Page Stream Response */ | |
660 | resp.low = QI_PSTRM_IDX(req->prg_index) | | |
661 | QI_PSTRM_PRIV(req->private) | QI_PSTRM_BUS(req->bus) | | |
662 | QI_PSTRM_PASID(req->pasid) | QI_PSTRM_RESP_TYPE; | |
663 | resp.high = QI_PSTRM_ADDR(address) | QI_PSTRM_DEVFN(req->devfn) | | |
664 | QI_PSTRM_RESP_CODE(result); | |
665 | ||
26322ab5 | 666 | qi_submit_sync(&resp, iommu); |
a222a7f0 DW |
667 | } |
668 | ||
669 | head = (head + sizeof(*req)) & PRQ_RING_MASK; | |
670 | } | |
671 | ||
672 | dmar_writeq(iommu->reg + DMAR_PQH_REG, tail); | |
673 | ||
674 | return IRQ_RETVAL(handled); | |
675 | } |