GNU Linux-libre 5.4.274-gnu1
[releases.git] / arch / powerpc / platforms / powernv / npu-dma.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * This file implements the DMA operations for NVLink devices. The NPU
4  * devices all point to the same iommu table as the parent PCI device.
5  *
6  * Copyright Alistair Popple, IBM Corporation 2015.
7  */
8
9 #include <linux/mmu_notifier.h>
10 #include <linux/mmu_context.h>
11 #include <linux/of.h>
12 #include <linux/pci.h>
13 #include <linux/memblock.h>
14 #include <linux/sizes.h>
15
16 #include <asm/debugfs.h>
17 #include <asm/powernv.h>
18 #include <asm/opal.h>
19
20 #include "pci.h"
21
22 static struct pci_dev *get_pci_dev(struct device_node *dn)
23 {
24         struct pci_dn *pdn = PCI_DN(dn);
25         struct pci_dev *pdev;
26
27         pdev = pci_get_domain_bus_and_slot(pci_domain_nr(pdn->phb->bus),
28                                            pdn->busno, pdn->devfn);
29
30         /*
31          * pci_get_domain_bus_and_slot() increased the reference count of
32          * the PCI device, but callers don't need that actually as the PE
33          * already holds a reference to the device. Since callers aren't
34          * aware of the reference count change, call pci_dev_put() now to
35          * avoid leaks.
36          */
37         if (pdev)
38                 pci_dev_put(pdev);
39
40         return pdev;
41 }
42
43 /* Given a NPU device get the associated PCI device. */
44 struct pci_dev *pnv_pci_get_gpu_dev(struct pci_dev *npdev)
45 {
46         struct device_node *dn;
47         struct pci_dev *gpdev;
48
49         if (WARN_ON(!npdev))
50                 return NULL;
51
52         if (WARN_ON(!npdev->dev.of_node))
53                 return NULL;
54
55         /* Get assoicated PCI device */
56         dn = of_parse_phandle(npdev->dev.of_node, "ibm,gpu", 0);
57         if (!dn)
58                 return NULL;
59
60         gpdev = get_pci_dev(dn);
61         of_node_put(dn);
62
63         return gpdev;
64 }
65 EXPORT_SYMBOL(pnv_pci_get_gpu_dev);
66
67 /* Given the real PCI device get a linked NPU device. */
68 struct pci_dev *pnv_pci_get_npu_dev(struct pci_dev *gpdev, int index)
69 {
70         struct device_node *dn;
71         struct pci_dev *npdev;
72
73         if (WARN_ON(!gpdev))
74                 return NULL;
75
76         /* Not all PCI devices have device-tree nodes */
77         if (!gpdev->dev.of_node)
78                 return NULL;
79
80         /* Get assoicated PCI device */
81         dn = of_parse_phandle(gpdev->dev.of_node, "ibm,npu", index);
82         if (!dn)
83                 return NULL;
84
85         npdev = get_pci_dev(dn);
86         of_node_put(dn);
87
88         return npdev;
89 }
90 EXPORT_SYMBOL(pnv_pci_get_npu_dev);
91
92 #ifdef CONFIG_IOMMU_API
93 /*
94  * Returns the PE assoicated with the PCI device of the given
95  * NPU. Returns the linked pci device if pci_dev != NULL.
96  */
97 static struct pnv_ioda_pe *get_gpu_pci_dev_and_pe(struct pnv_ioda_pe *npe,
98                                                   struct pci_dev **gpdev)
99 {
100         struct pnv_phb *phb;
101         struct pci_controller *hose;
102         struct pci_dev *pdev;
103         struct pnv_ioda_pe *pe;
104         struct pci_dn *pdn;
105
106         pdev = pnv_pci_get_gpu_dev(npe->pdev);
107         if (!pdev)
108                 return NULL;
109
110         pdn = pci_get_pdn(pdev);
111         if (WARN_ON(!pdn || pdn->pe_number == IODA_INVALID_PE))
112                 return NULL;
113
114         hose = pci_bus_to_host(pdev->bus);
115         phb = hose->private_data;
116         pe = &phb->ioda.pe_array[pdn->pe_number];
117
118         if (gpdev)
119                 *gpdev = pdev;
120
121         return pe;
122 }
123
124 static long pnv_npu_unset_window(struct iommu_table_group *table_group,
125                 int num);
126
127 static long pnv_npu_set_window(struct iommu_table_group *table_group, int num,
128                 struct iommu_table *tbl)
129 {
130         struct pnv_ioda_pe *npe = container_of(table_group, struct pnv_ioda_pe,
131                         table_group);
132         struct pnv_phb *phb = npe->phb;
133         int64_t rc;
134         const unsigned long size = tbl->it_indirect_levels ?
135                 tbl->it_level_size : tbl->it_size;
136         const __u64 start_addr = tbl->it_offset << tbl->it_page_shift;
137         const __u64 win_size = tbl->it_size << tbl->it_page_shift;
138         int num2 = (num == 0) ? 1 : 0;
139
140         /* NPU has just one TVE so if there is another table, remove it first */
141         if (npe->table_group.tables[num2])
142                 pnv_npu_unset_window(&npe->table_group, num2);
143
144         pe_info(npe, "Setting up window %llx..%llx pg=%lx\n",
145                         start_addr, start_addr + win_size - 1,
146                         IOMMU_PAGE_SIZE(tbl));
147
148         rc = opal_pci_map_pe_dma_window(phb->opal_id,
149                         npe->pe_number,
150                         npe->pe_number,
151                         tbl->it_indirect_levels + 1,
152                         __pa(tbl->it_base),
153                         size << 3,
154                         IOMMU_PAGE_SIZE(tbl));
155         if (rc) {
156                 pe_err(npe, "Failed to configure TCE table, err %lld\n", rc);
157                 return rc;
158         }
159         pnv_pci_ioda2_tce_invalidate_entire(phb, false);
160
161         /* Add the table to the list so its TCE cache will get invalidated */
162         pnv_pci_link_table_and_group(phb->hose->node, num,
163                         tbl, &npe->table_group);
164
165         return 0;
166 }
167
168 static long pnv_npu_unset_window(struct iommu_table_group *table_group, int num)
169 {
170         struct pnv_ioda_pe *npe = container_of(table_group, struct pnv_ioda_pe,
171                         table_group);
172         struct pnv_phb *phb = npe->phb;
173         int64_t rc;
174
175         if (!npe->table_group.tables[num])
176                 return 0;
177
178         pe_info(npe, "Removing DMA window\n");
179
180         rc = opal_pci_map_pe_dma_window(phb->opal_id, npe->pe_number,
181                         npe->pe_number,
182                         0/* levels */, 0/* table address */,
183                         0/* table size */, 0/* page size */);
184         if (rc) {
185                 pe_err(npe, "Unmapping failed, ret = %lld\n", rc);
186                 return rc;
187         }
188         pnv_pci_ioda2_tce_invalidate_entire(phb, false);
189
190         pnv_pci_unlink_table_and_group(npe->table_group.tables[num],
191                         &npe->table_group);
192
193         return 0;
194 }
195
196 /* Switch ownership from platform code to external user (e.g. VFIO) */
197 static void pnv_npu_take_ownership(struct iommu_table_group *table_group)
198 {
199         struct pnv_ioda_pe *npe = container_of(table_group, struct pnv_ioda_pe,
200                         table_group);
201         struct pnv_phb *phb = npe->phb;
202         int64_t rc;
203         struct pci_dev *gpdev = NULL;
204
205         /*
206          * Note: NPU has just a single TVE in the hardware which means that
207          * while used by the kernel, it can have either 32bit window or
208          * DMA bypass but never both. So we deconfigure 32bit window only
209          * if it was enabled at the moment of ownership change.
210          */
211         if (npe->table_group.tables[0]) {
212                 pnv_npu_unset_window(&npe->table_group, 0);
213                 return;
214         }
215
216         /* Disable bypass */
217         rc = opal_pci_map_pe_dma_window_real(phb->opal_id,
218                         npe->pe_number, npe->pe_number,
219                         0 /* bypass base */, 0);
220         if (rc) {
221                 pe_err(npe, "Failed to disable bypass, err %lld\n", rc);
222                 return;
223         }
224         pnv_pci_ioda2_tce_invalidate_entire(npe->phb, false);
225
226         get_gpu_pci_dev_and_pe(npe, &gpdev);
227         if (gpdev)
228                 pnv_npu2_unmap_lpar_dev(gpdev);
229 }
230
231 static void pnv_npu_release_ownership(struct iommu_table_group *table_group)
232 {
233         struct pnv_ioda_pe *npe = container_of(table_group, struct pnv_ioda_pe,
234                         table_group);
235         struct pci_dev *gpdev = NULL;
236
237         get_gpu_pci_dev_and_pe(npe, &gpdev);
238         if (gpdev)
239                 pnv_npu2_map_lpar_dev(gpdev, 0, MSR_DR | MSR_PR | MSR_HV);
240 }
241
242 static struct iommu_table_group_ops pnv_pci_npu_ops = {
243         .set_window = pnv_npu_set_window,
244         .unset_window = pnv_npu_unset_window,
245         .take_ownership = pnv_npu_take_ownership,
246         .release_ownership = pnv_npu_release_ownership,
247 };
248 #endif /* !CONFIG_IOMMU_API */
249
250 /*
251  * NPU2 ATS
252  */
253 /* Maximum possible number of ATSD MMIO registers per NPU */
254 #define NV_NMMU_ATSD_REGS 8
255 #define NV_NPU_MAX_PE_NUM       16
256
257 /*
258  * A compound NPU IOMMU group which might consist of 1 GPU + 2xNPUs (POWER8) or
259  * up to 3 x (GPU + 2xNPUs) (POWER9).
260  */
261 struct npu_comp {
262         struct iommu_table_group table_group;
263         int pe_num;
264         struct pnv_ioda_pe *pe[NV_NPU_MAX_PE_NUM];
265 };
266
267 /* An NPU descriptor, valid for POWER9 only */
268 struct npu {
269         int index;
270         struct npu_comp npucomp;
271 };
272
273 #ifdef CONFIG_IOMMU_API
274 static long pnv_npu_peers_create_table_userspace(
275                 struct iommu_table_group *table_group,
276                 int num, __u32 page_shift, __u64 window_size, __u32 levels,
277                 struct iommu_table **ptbl)
278 {
279         struct npu_comp *npucomp = container_of(table_group, struct npu_comp,
280                         table_group);
281
282         if (!npucomp->pe_num || !npucomp->pe[0] ||
283                         !npucomp->pe[0]->table_group.ops ||
284                         !npucomp->pe[0]->table_group.ops->create_table)
285                 return -EFAULT;
286
287         return npucomp->pe[0]->table_group.ops->create_table(
288                         &npucomp->pe[0]->table_group, num, page_shift,
289                         window_size, levels, ptbl);
290 }
291
292 static long pnv_npu_peers_set_window(struct iommu_table_group *table_group,
293                 int num, struct iommu_table *tbl)
294 {
295         int i, j;
296         long ret = 0;
297         struct npu_comp *npucomp = container_of(table_group, struct npu_comp,
298                         table_group);
299
300         for (i = 0; i < npucomp->pe_num; ++i) {
301                 struct pnv_ioda_pe *pe = npucomp->pe[i];
302
303                 if (!pe->table_group.ops->set_window)
304                         continue;
305
306                 ret = pe->table_group.ops->set_window(&pe->table_group,
307                                 num, tbl);
308                 if (ret)
309                         break;
310         }
311
312         if (ret) {
313                 for (j = 0; j < i; ++j) {
314                         struct pnv_ioda_pe *pe = npucomp->pe[j];
315
316                         if (!pe->table_group.ops->unset_window)
317                                 continue;
318
319                         ret = pe->table_group.ops->unset_window(
320                                         &pe->table_group, num);
321                         if (ret)
322                                 break;
323                 }
324         } else {
325                 table_group->tables[num] = iommu_tce_table_get(tbl);
326         }
327
328         return ret;
329 }
330
331 static long pnv_npu_peers_unset_window(struct iommu_table_group *table_group,
332                 int num)
333 {
334         int i, j;
335         long ret = 0;
336         struct npu_comp *npucomp = container_of(table_group, struct npu_comp,
337                         table_group);
338
339         for (i = 0; i < npucomp->pe_num; ++i) {
340                 struct pnv_ioda_pe *pe = npucomp->pe[i];
341
342                 WARN_ON(npucomp->table_group.tables[num] !=
343                                 table_group->tables[num]);
344                 if (!npucomp->table_group.tables[num])
345                         continue;
346
347                 if (!pe->table_group.ops->unset_window)
348                         continue;
349
350                 ret = pe->table_group.ops->unset_window(&pe->table_group, num);
351                 if (ret)
352                         break;
353         }
354
355         if (ret) {
356                 for (j = 0; j < i; ++j) {
357                         struct pnv_ioda_pe *pe = npucomp->pe[j];
358
359                         if (!npucomp->table_group.tables[num])
360                                 continue;
361
362                         if (!pe->table_group.ops->set_window)
363                                 continue;
364
365                         ret = pe->table_group.ops->set_window(&pe->table_group,
366                                         num, table_group->tables[num]);
367                         if (ret)
368                                 break;
369                 }
370         } else if (table_group->tables[num]) {
371                 iommu_tce_table_put(table_group->tables[num]);
372                 table_group->tables[num] = NULL;
373         }
374
375         return ret;
376 }
377
378 static void pnv_npu_peers_take_ownership(struct iommu_table_group *table_group)
379 {
380         int i;
381         struct npu_comp *npucomp = container_of(table_group, struct npu_comp,
382                         table_group);
383
384         for (i = 0; i < npucomp->pe_num; ++i) {
385                 struct pnv_ioda_pe *pe = npucomp->pe[i];
386
387                 if (!pe->table_group.ops ||
388                     !pe->table_group.ops->take_ownership)
389                         continue;
390                 pe->table_group.ops->take_ownership(&pe->table_group);
391         }
392 }
393
394 static void pnv_npu_peers_release_ownership(
395                 struct iommu_table_group *table_group)
396 {
397         int i;
398         struct npu_comp *npucomp = container_of(table_group, struct npu_comp,
399                         table_group);
400
401         for (i = 0; i < npucomp->pe_num; ++i) {
402                 struct pnv_ioda_pe *pe = npucomp->pe[i];
403
404                 if (!pe->table_group.ops ||
405                     !pe->table_group.ops->release_ownership)
406                         continue;
407                 pe->table_group.ops->release_ownership(&pe->table_group);
408         }
409 }
410
411 static struct iommu_table_group_ops pnv_npu_peers_ops = {
412         .get_table_size = pnv_pci_ioda2_get_table_size,
413         .create_table = pnv_npu_peers_create_table_userspace,
414         .set_window = pnv_npu_peers_set_window,
415         .unset_window = pnv_npu_peers_unset_window,
416         .take_ownership = pnv_npu_peers_take_ownership,
417         .release_ownership = pnv_npu_peers_release_ownership,
418 };
419
420 static void pnv_comp_attach_table_group(struct npu_comp *npucomp,
421                 struct pnv_ioda_pe *pe)
422 {
423         if (WARN_ON(npucomp->pe_num == NV_NPU_MAX_PE_NUM))
424                 return;
425
426         npucomp->pe[npucomp->pe_num] = pe;
427         ++npucomp->pe_num;
428 }
429
430 struct iommu_table_group *pnv_try_setup_npu_table_group(struct pnv_ioda_pe *pe)
431 {
432         struct iommu_table_group *table_group;
433         struct npu_comp *npucomp;
434         struct pci_dev *gpdev = NULL;
435         struct pci_controller *hose;
436         struct pci_dev *npdev = NULL;
437
438         list_for_each_entry(gpdev, &pe->pbus->devices, bus_list) {
439                 npdev = pnv_pci_get_npu_dev(gpdev, 0);
440                 if (npdev)
441                         break;
442         }
443
444         if (!npdev)
445                 /* It is not an NPU attached device, skip */
446                 return NULL;
447
448         hose = pci_bus_to_host(npdev->bus);
449
450         if (hose->npu) {
451                 table_group = &hose->npu->npucomp.table_group;
452
453                 if (!table_group->group) {
454                         table_group->ops = &pnv_npu_peers_ops;
455                         iommu_register_group(table_group,
456                                         hose->global_number,
457                                         pe->pe_number);
458                 }
459         } else {
460                 /* Create a group for 1 GPU and attached NPUs for POWER8 */
461                 pe->npucomp = kzalloc(sizeof(*pe->npucomp), GFP_KERNEL);
462                 table_group = &pe->npucomp->table_group;
463                 table_group->ops = &pnv_npu_peers_ops;
464                 iommu_register_group(table_group, hose->global_number,
465                                 pe->pe_number);
466         }
467
468         /* Steal capabilities from a GPU PE */
469         table_group->max_dynamic_windows_supported =
470                 pe->table_group.max_dynamic_windows_supported;
471         table_group->tce32_start = pe->table_group.tce32_start;
472         table_group->tce32_size = pe->table_group.tce32_size;
473         table_group->max_levels = pe->table_group.max_levels;
474         if (!table_group->pgsizes)
475                 table_group->pgsizes = pe->table_group.pgsizes;
476
477         npucomp = container_of(table_group, struct npu_comp, table_group);
478         pnv_comp_attach_table_group(npucomp, pe);
479
480         return table_group;
481 }
482
483 struct iommu_table_group *pnv_npu_compound_attach(struct pnv_ioda_pe *pe)
484 {
485         struct iommu_table_group *table_group;
486         struct npu_comp *npucomp;
487         struct pci_dev *gpdev = NULL;
488         struct pci_dev *npdev;
489         struct pnv_ioda_pe *gpe = get_gpu_pci_dev_and_pe(pe, &gpdev);
490
491         WARN_ON(!(pe->flags & PNV_IODA_PE_DEV));
492         if (!gpe)
493                 return NULL;
494
495         /*
496          * IODA2 bridges get this set up from pci_controller_ops::setup_bridge
497          * but NPU bridges do not have this hook defined so we do it here.
498          * We do not setup other table group parameters as they won't be used
499          * anyway - NVLink bridges are subordinate PEs.
500          */
501         pe->table_group.ops = &pnv_pci_npu_ops;
502
503         table_group = iommu_group_get_iommudata(
504                         iommu_group_get(&gpdev->dev));
505
506         /*
507          * On P9 NPU PHB and PCI PHB support different page sizes,
508          * keep only matching. We expect here that NVLink bridge PE pgsizes is
509          * initialized by the caller.
510          */
511         table_group->pgsizes &= pe->table_group.pgsizes;
512         npucomp = container_of(table_group, struct npu_comp, table_group);
513         pnv_comp_attach_table_group(npucomp, pe);
514
515         list_for_each_entry(npdev, &pe->phb->hose->bus->devices, bus_list) {
516                 struct pci_dev *gpdevtmp = pnv_pci_get_gpu_dev(npdev);
517
518                 if (gpdevtmp != gpdev)
519                         continue;
520
521                 iommu_add_device(table_group, &npdev->dev);
522         }
523
524         return table_group;
525 }
526 #endif /* CONFIG_IOMMU_API */
527
528 int pnv_npu2_init(struct pci_controller *hose)
529 {
530         static int npu_index;
531         struct npu *npu;
532         int ret;
533
534         npu = kzalloc(sizeof(*npu), GFP_KERNEL);
535         if (!npu)
536                 return -ENOMEM;
537
538         npu_index++;
539         if (WARN_ON(npu_index >= NV_MAX_NPUS)) {
540                 ret = -ENOSPC;
541                 goto fail_exit;
542         }
543         npu->index = npu_index;
544         hose->npu = npu;
545
546         return 0;
547
548 fail_exit:
549         kfree(npu);
550         return ret;
551 }
552
553 int pnv_npu2_map_lpar_dev(struct pci_dev *gpdev, unsigned int lparid,
554                 unsigned long msr)
555 {
556         int ret;
557         struct pci_dev *npdev = pnv_pci_get_npu_dev(gpdev, 0);
558         struct pci_controller *hose;
559         struct pnv_phb *nphb;
560
561         if (!npdev)
562                 return -ENODEV;
563
564         hose = pci_bus_to_host(npdev->bus);
565         if (hose->npu == NULL) {
566                 dev_info_once(&npdev->dev, "Nvlink1 does not support contexts");
567                 return 0;
568         }
569
570         nphb = hose->private_data;
571
572         dev_dbg(&gpdev->dev, "Map LPAR opalid=%llu lparid=%u\n",
573                         nphb->opal_id, lparid);
574         /*
575          * Currently we only support radix and non-zero LPCR only makes sense
576          * for hash tables so skiboot expects the LPCR parameter to be a zero.
577          */
578         ret = opal_npu_map_lpar(nphb->opal_id, pci_dev_id(gpdev), lparid,
579                                 0 /* LPCR bits */);
580         if (ret) {
581                 dev_err(&gpdev->dev, "Error %d mapping device to LPAR\n", ret);
582                 return ret;
583         }
584
585         dev_dbg(&gpdev->dev, "init context opalid=%llu msr=%lx\n",
586                         nphb->opal_id, msr);
587         ret = opal_npu_init_context(nphb->opal_id, 0/*__unused*/, msr,
588                                     pci_dev_id(gpdev));
589         if (ret < 0)
590                 dev_err(&gpdev->dev, "Failed to init context: %d\n", ret);
591         else
592                 ret = 0;
593
594         return 0;
595 }
596 EXPORT_SYMBOL_GPL(pnv_npu2_map_lpar_dev);
597
598 void pnv_npu2_map_lpar(struct pnv_ioda_pe *gpe, unsigned long msr)
599 {
600         struct pci_dev *gpdev;
601
602         list_for_each_entry(gpdev, &gpe->pbus->devices, bus_list)
603                 pnv_npu2_map_lpar_dev(gpdev, 0, msr);
604 }
605
606 int pnv_npu2_unmap_lpar_dev(struct pci_dev *gpdev)
607 {
608         int ret;
609         struct pci_dev *npdev = pnv_pci_get_npu_dev(gpdev, 0);
610         struct pci_controller *hose;
611         struct pnv_phb *nphb;
612
613         if (!npdev)
614                 return -ENODEV;
615
616         hose = pci_bus_to_host(npdev->bus);
617         if (hose->npu == NULL) {
618                 dev_info_once(&npdev->dev, "Nvlink1 does not support contexts");
619                 return 0;
620         }
621
622         nphb = hose->private_data;
623
624         dev_dbg(&gpdev->dev, "destroy context opalid=%llu\n",
625                         nphb->opal_id);
626         ret = opal_npu_destroy_context(nphb->opal_id, 0/*__unused*/,
627                                        pci_dev_id(gpdev));
628         if (ret < 0) {
629                 dev_err(&gpdev->dev, "Failed to destroy context: %d\n", ret);
630                 return ret;
631         }
632
633         /* Set LPID to 0 anyway, just to be safe */
634         dev_dbg(&gpdev->dev, "Map LPAR opalid=%llu lparid=0\n", nphb->opal_id);
635         ret = opal_npu_map_lpar(nphb->opal_id, pci_dev_id(gpdev), 0 /*LPID*/,
636                                 0 /* LPCR bits */);
637         if (ret)
638                 dev_err(&gpdev->dev, "Error %d mapping device to LPAR\n", ret);
639
640         return ret;
641 }
642 EXPORT_SYMBOL_GPL(pnv_npu2_unmap_lpar_dev);