1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * PCI Hotplug Driver for PowerPC PowerNV platform.
4 *
5 * Copyright Gavin Shan, IBM Corporation 2016.
6 */
7
8 #include <linux/libfdt.h>
9 #include <linux/module.h>
10 #include <linux/pci.h>
11 #include <linux/pci_hotplug.h>
12
13 #include <asm/opal.h>
14 #include <asm/pnv-pci.h>
15 #include <asm/ppc-pci.h>
16
17 #define DRIVER_VERSION "0.1"
18 #define DRIVER_AUTHOR "Gavin Shan, IBM Corporation"
19 #define DRIVER_DESC "PowerPC PowerNV PCI Hotplug Driver"
20
21 #define SLOT_WARN(sl, x...) \
22 ((sl)->pdev ? pci_warn((sl)->pdev, x) : dev_warn(&(sl)->bus->dev, x))
23
24 struct pnv_php_event {
25 bool added;
26 struct pnv_php_slot *php_slot;
27 struct work_struct work;
28 };
29
30 static LIST_HEAD(pnv_php_slot_list);
31 static DEFINE_SPINLOCK(pnv_php_lock);
32
33 static void pnv_php_register(struct device_node *dn);
34 static void pnv_php_unregister_one(struct device_node *dn);
35 static void pnv_php_unregister(struct device_node *dn);
36
pnv_php_disable_irq(struct pnv_php_slot * php_slot,bool disable_device)37 static void pnv_php_disable_irq(struct pnv_php_slot *php_slot,
38 bool disable_device)
39 {
40 struct pci_dev *pdev = php_slot->pdev;
41 int irq = php_slot->irq;
42 u16 ctrl;
43
44 if (php_slot->irq > 0) {
45 pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &ctrl);
46 ctrl &= ~(PCI_EXP_SLTCTL_HPIE |
47 PCI_EXP_SLTCTL_PDCE |
48 PCI_EXP_SLTCTL_DLLSCE);
49 pcie_capability_write_word(pdev, PCI_EXP_SLTCTL, ctrl);
50
51 free_irq(php_slot->irq, php_slot);
52 php_slot->irq = 0;
53 }
54
55 if (php_slot->wq) {
56 destroy_workqueue(php_slot->wq);
57 php_slot->wq = NULL;
58 }
59
60 if (disable_device || irq > 0) {
61 if (pdev->msix_enabled)
62 pci_disable_msix(pdev);
63 else if (pdev->msi_enabled)
64 pci_disable_msi(pdev);
65
66 pci_disable_device(pdev);
67 }
68 }
69
pnv_php_free_slot(struct kref * kref)70 static void pnv_php_free_slot(struct kref *kref)
71 {
72 struct pnv_php_slot *php_slot = container_of(kref,
73 struct pnv_php_slot, kref);
74
75 WARN_ON(!list_empty(&php_slot->children));
76 pnv_php_disable_irq(php_slot, false);
77 kfree(php_slot->name);
78 kfree(php_slot);
79 }
80
pnv_php_put_slot(struct pnv_php_slot * php_slot)81 static inline void pnv_php_put_slot(struct pnv_php_slot *php_slot)
82 {
83
84 if (!php_slot)
85 return;
86
87 kref_put(&php_slot->kref, pnv_php_free_slot);
88 }
89
pnv_php_match(struct device_node * dn,struct pnv_php_slot * php_slot)90 static struct pnv_php_slot *pnv_php_match(struct device_node *dn,
91 struct pnv_php_slot *php_slot)
92 {
93 struct pnv_php_slot *target, *tmp;
94
95 if (php_slot->dn == dn) {
96 kref_get(&php_slot->kref);
97 return php_slot;
98 }
99
100 list_for_each_entry(tmp, &php_slot->children, link) {
101 target = pnv_php_match(dn, tmp);
102 if (target)
103 return target;
104 }
105
106 return NULL;
107 }
108
pnv_php_find_slot(struct device_node * dn)109 struct pnv_php_slot *pnv_php_find_slot(struct device_node *dn)
110 {
111 struct pnv_php_slot *php_slot, *tmp;
112 unsigned long flags;
113
114 spin_lock_irqsave(&pnv_php_lock, flags);
115 list_for_each_entry(tmp, &pnv_php_slot_list, link) {
116 php_slot = pnv_php_match(dn, tmp);
117 if (php_slot) {
118 spin_unlock_irqrestore(&pnv_php_lock, flags);
119 return php_slot;
120 }
121 }
122 spin_unlock_irqrestore(&pnv_php_lock, flags);
123
124 return NULL;
125 }
126 EXPORT_SYMBOL_GPL(pnv_php_find_slot);
127
128 /*
129 * Remove pdn for all children of the indicated device node.
130 * The function should remove pdn in a depth-first manner.
131 */
pnv_php_rmv_pdns(struct device_node * dn)132 static void pnv_php_rmv_pdns(struct device_node *dn)
133 {
134 struct device_node *child;
135
136 for_each_child_of_node(dn, child) {
137 pnv_php_rmv_pdns(child);
138
139 pci_remove_device_node_info(child);
140 }
141 }
142
143 /*
144 * Detach all child nodes of the indicated device nodes. The
145 * function should handle device nodes in depth-first manner.
146 *
147 * We should not invoke of_node_release() as the memory for
148 * individual device node is part of large memory block. The
149 * large block is allocated from memblock (system bootup) or
150 * kmalloc() when unflattening the device tree by OF changeset.
151 * We can not free the large block allocated from memblock. For
152 * later case, it should be released at once.
153 */
pnv_php_detach_device_nodes(struct device_node * parent)154 static void pnv_php_detach_device_nodes(struct device_node *parent)
155 {
156 struct device_node *dn;
157
158 for_each_child_of_node(parent, dn) {
159 pnv_php_detach_device_nodes(dn);
160
161 of_node_put(dn);
162 of_detach_node(dn);
163 }
164 }
165
pnv_php_rmv_devtree(struct pnv_php_slot * php_slot)166 static void pnv_php_rmv_devtree(struct pnv_php_slot *php_slot)
167 {
168 pnv_php_rmv_pdns(php_slot->dn);
169
170 /*
171 * Decrease the refcount if the device nodes were created
172 * through OF changeset before detaching them.
173 */
174 if (php_slot->fdt)
175 of_changeset_destroy(&php_slot->ocs);
176 pnv_php_detach_device_nodes(php_slot->dn);
177
178 if (php_slot->fdt) {
179 kfree(php_slot->dt);
180 kfree(php_slot->fdt);
181 php_slot->dt = NULL;
182 php_slot->dn->child = NULL;
183 php_slot->fdt = NULL;
184 }
185 }
186
187 /*
188 * As the nodes in OF changeset are applied in reverse order, we
189 * need revert the nodes in advance so that we have correct node
190 * order after the changeset is applied.
191 */
pnv_php_reverse_nodes(struct device_node * parent)192 static void pnv_php_reverse_nodes(struct device_node *parent)
193 {
194 struct device_node *child, *next;
195
196 /* In-depth first */
197 for_each_child_of_node(parent, child)
198 pnv_php_reverse_nodes(child);
199
200 /* Reverse the nodes in the child list */
201 child = parent->child;
202 parent->child = NULL;
203 while (child) {
204 next = child->sibling;
205
206 child->sibling = parent->child;
207 parent->child = child;
208 child = next;
209 }
210 }
211
pnv_php_populate_changeset(struct of_changeset * ocs,struct device_node * dn)212 static int pnv_php_populate_changeset(struct of_changeset *ocs,
213 struct device_node *dn)
214 {
215 struct device_node *child;
216 int ret = 0;
217
218 for_each_child_of_node(dn, child) {
219 ret = of_changeset_attach_node(ocs, child);
220 if (ret) {
221 of_node_put(child);
222 break;
223 }
224
225 ret = pnv_php_populate_changeset(ocs, child);
226 if (ret) {
227 of_node_put(child);
228 break;
229 }
230 }
231
232 return ret;
233 }
234
pnv_php_add_one_pdn(struct device_node * dn,void * data)235 static void *pnv_php_add_one_pdn(struct device_node *dn, void *data)
236 {
237 struct pci_controller *hose = (struct pci_controller *)data;
238 struct pci_dn *pdn;
239
240 pdn = pci_add_device_node_info(hose, dn);
241 if (!pdn)
242 return ERR_PTR(-ENOMEM);
243
244 return NULL;
245 }
246
pnv_php_add_pdns(struct pnv_php_slot * slot)247 static void pnv_php_add_pdns(struct pnv_php_slot *slot)
248 {
249 struct pci_controller *hose = pci_bus_to_host(slot->bus);
250
251 pci_traverse_device_nodes(slot->dn, pnv_php_add_one_pdn, hose);
252 }
253
pnv_php_add_devtree(struct pnv_php_slot * php_slot)254 static int pnv_php_add_devtree(struct pnv_php_slot *php_slot)
255 {
256 void *fdt, *fdt1, *dt;
257 int ret;
258
259 /* We don't know the FDT blob size. We try to get it through
260 * maximal memory chunk and then copy it to another chunk that
261 * fits the real size.
262 */
263 fdt1 = kzalloc(0x10000, GFP_KERNEL);
264 if (!fdt1) {
265 ret = -ENOMEM;
266 goto out;
267 }
268
269 ret = pnv_pci_get_device_tree(php_slot->dn->phandle, fdt1, 0x10000);
270 if (ret) {
271 SLOT_WARN(php_slot, "Error %d getting FDT blob\n", ret);
272 goto free_fdt1;
273 }
274
275 fdt = kmemdup(fdt1, fdt_totalsize(fdt1), GFP_KERNEL);
276 if (!fdt) {
277 ret = -ENOMEM;
278 goto free_fdt1;
279 }
280
281 /* Unflatten device tree blob */
282 dt = of_fdt_unflatten_tree(fdt, php_slot->dn, NULL);
283 if (!dt) {
284 ret = -EINVAL;
285 SLOT_WARN(php_slot, "Cannot unflatten FDT\n");
286 goto free_fdt;
287 }
288
289 /* Initialize and apply the changeset */
290 of_changeset_init(&php_slot->ocs);
291 pnv_php_reverse_nodes(php_slot->dn);
292 ret = pnv_php_populate_changeset(&php_slot->ocs, php_slot->dn);
293 if (ret) {
294 pnv_php_reverse_nodes(php_slot->dn);
295 SLOT_WARN(php_slot, "Error %d populating changeset\n",
296 ret);
297 goto free_dt;
298 }
299
300 php_slot->dn->child = NULL;
301 ret = of_changeset_apply(&php_slot->ocs);
302 if (ret) {
303 SLOT_WARN(php_slot, "Error %d applying changeset\n", ret);
304 goto destroy_changeset;
305 }
306
307 /* Add device node firmware data */
308 pnv_php_add_pdns(php_slot);
309 php_slot->fdt = fdt;
310 php_slot->dt = dt;
311 kfree(fdt1);
312 goto out;
313
314 destroy_changeset:
315 of_changeset_destroy(&php_slot->ocs);
316 free_dt:
317 kfree(dt);
318 php_slot->dn->child = NULL;
319 free_fdt:
320 kfree(fdt);
321 free_fdt1:
322 kfree(fdt1);
323 out:
324 return ret;
325 }
326
to_pnv_php_slot(struct hotplug_slot * slot)327 static inline struct pnv_php_slot *to_pnv_php_slot(struct hotplug_slot *slot)
328 {
329 return container_of(slot, struct pnv_php_slot, slot);
330 }
331
pnv_php_set_slot_power_state(struct hotplug_slot * slot,uint8_t state)332 int pnv_php_set_slot_power_state(struct hotplug_slot *slot,
333 uint8_t state)
334 {
335 struct pnv_php_slot *php_slot = to_pnv_php_slot(slot);
336 struct opal_msg msg;
337 int ret;
338
339 ret = pnv_pci_set_power_state(php_slot->id, state, &msg);
340 if (ret > 0) {
341 if (be64_to_cpu(msg.params[1]) != php_slot->dn->phandle ||
342 be64_to_cpu(msg.params[2]) != state) {
343 SLOT_WARN(php_slot, "Wrong msg (%lld, %lld, %lld)\n",
344 be64_to_cpu(msg.params[1]),
345 be64_to_cpu(msg.params[2]),
346 be64_to_cpu(msg.params[3]));
347 return -ENOMSG;
348 }
349 if (be64_to_cpu(msg.params[3]) != OPAL_SUCCESS) {
350 ret = -ENODEV;
351 goto error;
352 }
353 } else if (ret < 0) {
354 goto error;
355 }
356
357 if (state == OPAL_PCI_SLOT_POWER_OFF || state == OPAL_PCI_SLOT_OFFLINE)
358 pnv_php_rmv_devtree(php_slot);
359 else
360 ret = pnv_php_add_devtree(php_slot);
361
362 return ret;
363
364 error:
365 SLOT_WARN(php_slot, "Error %d powering %s\n",
366 ret, (state == OPAL_PCI_SLOT_POWER_ON) ? "on" : "off");
367 return ret;
368 }
369 EXPORT_SYMBOL_GPL(pnv_php_set_slot_power_state);
370
pnv_php_get_power_state(struct hotplug_slot * slot,u8 * state)371 static int pnv_php_get_power_state(struct hotplug_slot *slot, u8 *state)
372 {
373 struct pnv_php_slot *php_slot = to_pnv_php_slot(slot);
374 uint8_t power_state = OPAL_PCI_SLOT_POWER_ON;
375 int ret;
376
377 /*
378 * Retrieve power status from firmware. If we fail
379 * getting that, the power status fails back to
380 * be on.
381 */
382 ret = pnv_pci_get_power_state(php_slot->id, &power_state);
383 if (ret) {
384 SLOT_WARN(php_slot, "Error %d getting power status\n",
385 ret);
386 } else {
387 *state = power_state;
388 }
389
390 return 0;
391 }
392
pnv_php_get_adapter_state(struct hotplug_slot * slot,u8 * state)393 static int pnv_php_get_adapter_state(struct hotplug_slot *slot, u8 *state)
394 {
395 struct pnv_php_slot *php_slot = to_pnv_php_slot(slot);
396 uint8_t presence = OPAL_PCI_SLOT_EMPTY;
397 int ret;
398
399 /*
400 * Retrieve presence status from firmware. If we can't
401 * get that, it will fail back to be empty.
402 */
403 ret = pnv_pci_get_presence_state(php_slot->id, &presence);
404 if (ret >= 0) {
405 *state = presence;
406 ret = 0;
407 } else {
408 SLOT_WARN(php_slot, "Error %d getting presence\n", ret);
409 }
410
411 return ret;
412 }
413
pnv_php_get_attention_state(struct hotplug_slot * slot,u8 * state)414 static int pnv_php_get_attention_state(struct hotplug_slot *slot, u8 *state)
415 {
416 struct pnv_php_slot *php_slot = to_pnv_php_slot(slot);
417
418 *state = php_slot->attention_state;
419 return 0;
420 }
421
pnv_php_set_attention_state(struct hotplug_slot * slot,u8 state)422 static int pnv_php_set_attention_state(struct hotplug_slot *slot, u8 state)
423 {
424 struct pnv_php_slot *php_slot = to_pnv_php_slot(slot);
425 struct pci_dev *bridge = php_slot->pdev;
426 u16 new, mask;
427
428 php_slot->attention_state = state;
429 if (!bridge)
430 return 0;
431
432 mask = PCI_EXP_SLTCTL_AIC;
433
434 if (state)
435 new = PCI_EXP_SLTCTL_ATTN_IND_ON;
436 else
437 new = PCI_EXP_SLTCTL_ATTN_IND_OFF;
438
439 pcie_capability_clear_and_set_word(bridge, PCI_EXP_SLTCTL, mask, new);
440
441 return 0;
442 }
443
pnv_php_enable(struct pnv_php_slot * php_slot,bool rescan)444 static int pnv_php_enable(struct pnv_php_slot *php_slot, bool rescan)
445 {
446 struct hotplug_slot *slot = &php_slot->slot;
447 uint8_t presence = OPAL_PCI_SLOT_EMPTY;
448 uint8_t power_status = OPAL_PCI_SLOT_POWER_ON;
449 int ret;
450
451 /* Check if the slot has been configured */
452 if (php_slot->state != PNV_PHP_STATE_REGISTERED)
453 return 0;
454
455 /* Retrieve slot presence status */
456 ret = pnv_php_get_adapter_state(slot, &presence);
457 if (ret)
458 return ret;
459
460 /*
461 * Proceed if there have nothing behind the slot. However,
462 * we should leave the slot in registered state at the
463 * beginning. Otherwise, the PCI devices inserted afterwards
464 * won't be probed and populated.
465 */
466 if (presence == OPAL_PCI_SLOT_EMPTY) {
467 if (!php_slot->power_state_check) {
468 php_slot->power_state_check = true;
469
470 return 0;
471 }
472
473 goto scan;
474 }
475
476 /*
477 * If the power supply to the slot is off, we can't detect
478 * adapter presence state. That means we have to turn the
479 * slot on before going to probe slot's presence state.
480 *
481 * On the first time, we don't change the power status to
482 * boost system boot with assumption that the firmware
483 * supplies consistent slot power status: empty slot always
484 * has its power off and non-empty slot has its power on.
485 */
486 if (!php_slot->power_state_check) {
487 php_slot->power_state_check = true;
488
489 ret = pnv_php_get_power_state(slot, &power_status);
490 if (ret)
491 return ret;
492
493 if (power_status != OPAL_PCI_SLOT_POWER_ON)
494 return 0;
495 }
496
497 /* Check the power status. Scan the slot if it is already on */
498 ret = pnv_php_get_power_state(slot, &power_status);
499 if (ret)
500 return ret;
501
502 if (power_status == OPAL_PCI_SLOT_POWER_ON)
503 goto scan;
504
505 /* Power is off, turn it on and then scan the slot */
506 ret = pnv_php_set_slot_power_state(slot, OPAL_PCI_SLOT_POWER_ON);
507 if (ret)
508 return ret;
509
510 scan:
511 if (presence == OPAL_PCI_SLOT_PRESENT) {
512 if (rescan) {
513 pci_lock_rescan_remove();
514 pci_hp_add_devices(php_slot->bus);
515 pci_unlock_rescan_remove();
516 }
517
518 /* Rescan for child hotpluggable slots */
519 php_slot->state = PNV_PHP_STATE_POPULATED;
520 if (rescan)
521 pnv_php_register(php_slot->dn);
522 } else {
523 php_slot->state = PNV_PHP_STATE_POPULATED;
524 }
525
526 return 0;
527 }
528
pnv_php_reset_slot(struct hotplug_slot * slot,bool probe)529 static int pnv_php_reset_slot(struct hotplug_slot *slot, bool probe)
530 {
531 struct pnv_php_slot *php_slot = to_pnv_php_slot(slot);
532 struct pci_dev *bridge = php_slot->pdev;
533 uint16_t sts;
534
535 /*
536 * The CAPI folks want pnv_php to drive OpenCAPI slots
537 * which don't have a bridge. Only claim to support
538 * reset_slot() if we have a bridge device (for now...)
539 */
540 if (probe)
541 return !bridge;
542
543 /* mask our interrupt while resetting the bridge */
544 if (php_slot->irq > 0)
545 disable_irq(php_slot->irq);
546
547 pci_bridge_secondary_bus_reset(bridge);
548
549 /* clear any state changes that happened due to the reset */
550 pcie_capability_read_word(php_slot->pdev, PCI_EXP_SLTSTA, &sts);
551 sts &= (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC);
552 pcie_capability_write_word(php_slot->pdev, PCI_EXP_SLTSTA, sts);
553
554 if (php_slot->irq > 0)
555 enable_irq(php_slot->irq);
556
557 return 0;
558 }
559
pnv_php_enable_slot(struct hotplug_slot * slot)560 static int pnv_php_enable_slot(struct hotplug_slot *slot)
561 {
562 struct pnv_php_slot *php_slot = to_pnv_php_slot(slot);
563
564 return pnv_php_enable(php_slot, true);
565 }
566
pnv_php_disable_slot(struct hotplug_slot * slot)567 static int pnv_php_disable_slot(struct hotplug_slot *slot)
568 {
569 struct pnv_php_slot *php_slot = to_pnv_php_slot(slot);
570 int ret;
571
572 /*
573 * Allow to disable a slot already in the registered state to
574 * cover cases where the slot couldn't be enabled and never
575 * reached the populated state
576 */
577 if (php_slot->state != PNV_PHP_STATE_POPULATED &&
578 php_slot->state != PNV_PHP_STATE_REGISTERED)
579 return 0;
580
581 /* Remove all devices behind the slot */
582 pci_lock_rescan_remove();
583 pci_hp_remove_devices(php_slot->bus);
584 pci_unlock_rescan_remove();
585
586 /* Detach the child hotpluggable slots */
587 pnv_php_unregister(php_slot->dn);
588
589 /* Notify firmware and remove device nodes */
590 ret = pnv_php_set_slot_power_state(slot, OPAL_PCI_SLOT_POWER_OFF);
591
592 php_slot->state = PNV_PHP_STATE_REGISTERED;
593 return ret;
594 }
595
596 static const struct hotplug_slot_ops php_slot_ops = {
597 .get_power_status = pnv_php_get_power_state,
598 .get_adapter_status = pnv_php_get_adapter_state,
599 .get_attention_status = pnv_php_get_attention_state,
600 .set_attention_status = pnv_php_set_attention_state,
601 .enable_slot = pnv_php_enable_slot,
602 .disable_slot = pnv_php_disable_slot,
603 .reset_slot = pnv_php_reset_slot,
604 };
605
pnv_php_release(struct pnv_php_slot * php_slot)606 static void pnv_php_release(struct pnv_php_slot *php_slot)
607 {
608 unsigned long flags;
609
610 /* Remove from global or child list */
611 spin_lock_irqsave(&pnv_php_lock, flags);
612 list_del(&php_slot->link);
613 spin_unlock_irqrestore(&pnv_php_lock, flags);
614
615 /* Detach from parent */
616 pnv_php_put_slot(php_slot);
617 pnv_php_put_slot(php_slot->parent);
618 }
619
pnv_php_alloc_slot(struct device_node * dn)620 static struct pnv_php_slot *pnv_php_alloc_slot(struct device_node *dn)
621 {
622 struct pnv_php_slot *php_slot;
623 struct pci_bus *bus;
624 const char *label;
625 uint64_t id;
626 int ret;
627
628 ret = of_property_read_string(dn, "ibm,slot-label", &label);
629 if (ret)
630 return NULL;
631
632 if (pnv_pci_get_slot_id(dn, &id))
633 return NULL;
634
635 bus = pci_find_bus_by_node(dn);
636 if (!bus)
637 return NULL;
638
639 php_slot = kzalloc(sizeof(*php_slot), GFP_KERNEL);
640 if (!php_slot)
641 return NULL;
642
643 php_slot->name = kstrdup(label, GFP_KERNEL);
644 if (!php_slot->name) {
645 kfree(php_slot);
646 return NULL;
647 }
648
649 if (dn->child && PCI_DN(dn->child))
650 php_slot->slot_no = PCI_SLOT(PCI_DN(dn->child)->devfn);
651 else
652 php_slot->slot_no = -1; /* Placeholder slot */
653
654 kref_init(&php_slot->kref);
655 php_slot->state = PNV_PHP_STATE_INITIALIZED;
656 php_slot->dn = dn;
657 php_slot->pdev = bus->self;
658 php_slot->bus = bus;
659 php_slot->id = id;
660 php_slot->power_state_check = false;
661 php_slot->slot.ops = &php_slot_ops;
662
663 INIT_LIST_HEAD(&php_slot->children);
664 INIT_LIST_HEAD(&php_slot->link);
665
666 return php_slot;
667 }
668
pnv_php_register_slot(struct pnv_php_slot * php_slot)669 static int pnv_php_register_slot(struct pnv_php_slot *php_slot)
670 {
671 struct pnv_php_slot *parent;
672 struct device_node *dn = php_slot->dn;
673 unsigned long flags;
674 int ret;
675
676 /* Check if the slot is registered or not */
677 parent = pnv_php_find_slot(php_slot->dn);
678 if (parent) {
679 pnv_php_put_slot(parent);
680 return -EEXIST;
681 }
682
683 /* Register PCI slot */
684 ret = pci_hp_register(&php_slot->slot, php_slot->bus,
685 php_slot->slot_no, php_slot->name);
686 if (ret) {
687 SLOT_WARN(php_slot, "Error %d registering slot\n", ret);
688 return ret;
689 }
690
691 /* Attach to the parent's child list or global list */
692 while ((dn = of_get_parent(dn))) {
693 if (!PCI_DN(dn)) {
694 of_node_put(dn);
695 break;
696 }
697
698 parent = pnv_php_find_slot(dn);
699 if (parent) {
700 of_node_put(dn);
701 break;
702 }
703
704 of_node_put(dn);
705 }
706
707 spin_lock_irqsave(&pnv_php_lock, flags);
708 php_slot->parent = parent;
709 if (parent)
710 list_add_tail(&php_slot->link, &parent->children);
711 else
712 list_add_tail(&php_slot->link, &pnv_php_slot_list);
713 spin_unlock_irqrestore(&pnv_php_lock, flags);
714
715 php_slot->state = PNV_PHP_STATE_REGISTERED;
716 return 0;
717 }
718
pnv_php_enable_msix(struct pnv_php_slot * php_slot)719 static int pnv_php_enable_msix(struct pnv_php_slot *php_slot)
720 {
721 struct pci_dev *pdev = php_slot->pdev;
722 struct msix_entry entry;
723 int nr_entries, ret;
724 u16 pcie_flag;
725
726 /* Get total number of MSIx entries */
727 nr_entries = pci_msix_vec_count(pdev);
728 if (nr_entries < 0)
729 return nr_entries;
730
731 /* Check hotplug MSIx entry is in range */
732 pcie_capability_read_word(pdev, PCI_EXP_FLAGS, &pcie_flag);
733 entry.entry = (pcie_flag & PCI_EXP_FLAGS_IRQ) >> 9;
734 if (entry.entry >= nr_entries)
735 return -ERANGE;
736
737 /* Enable MSIx */
738 ret = pci_enable_msix_exact(pdev, &entry, 1);
739 if (ret) {
740 SLOT_WARN(php_slot, "Error %d enabling MSIx\n", ret);
741 return ret;
742 }
743
744 return entry.vector;
745 }
746
pnv_php_event_handler(struct work_struct * work)747 static void pnv_php_event_handler(struct work_struct *work)
748 {
749 struct pnv_php_event *event =
750 container_of(work, struct pnv_php_event, work);
751 struct pnv_php_slot *php_slot = event->php_slot;
752
753 if (event->added)
754 pnv_php_enable_slot(&php_slot->slot);
755 else
756 pnv_php_disable_slot(&php_slot->slot);
757
758 kfree(event);
759 }
760
pnv_php_interrupt(int irq,void * data)761 static irqreturn_t pnv_php_interrupt(int irq, void *data)
762 {
763 struct pnv_php_slot *php_slot = data;
764 struct pci_dev *pchild, *pdev = php_slot->pdev;
765 struct eeh_dev *edev;
766 struct eeh_pe *pe;
767 struct pnv_php_event *event;
768 u16 sts, lsts;
769 u8 presence;
770 bool added;
771 unsigned long flags;
772 int ret;
773
774 pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &sts);
775 sts &= (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC);
776 pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, sts);
777
778 pci_dbg(pdev, "PCI slot [%s]: HP int! DLAct: %d, PresDet: %d\n",
779 php_slot->name,
780 !!(sts & PCI_EXP_SLTSTA_DLLSC),
781 !!(sts & PCI_EXP_SLTSTA_PDC));
782
783 if (sts & PCI_EXP_SLTSTA_DLLSC) {
784 pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lsts);
785 added = !!(lsts & PCI_EXP_LNKSTA_DLLLA);
786 } else if (!(php_slot->flags & PNV_PHP_FLAG_BROKEN_PDC) &&
787 (sts & PCI_EXP_SLTSTA_PDC)) {
788 ret = pnv_pci_get_presence_state(php_slot->id, &presence);
789 if (ret) {
790 SLOT_WARN(php_slot,
791 "PCI slot [%s] error %d getting presence (0x%04x), to retry the operation.\n",
792 php_slot->name, ret, sts);
793 return IRQ_HANDLED;
794 }
795
796 added = !!(presence == OPAL_PCI_SLOT_PRESENT);
797 } else {
798 pci_dbg(pdev, "PCI slot [%s]: Spurious IRQ?\n", php_slot->name);
799 return IRQ_NONE;
800 }
801
802 /* Freeze the removed PE to avoid unexpected error reporting */
803 if (!added) {
804 pchild = list_first_entry_or_null(&php_slot->bus->devices,
805 struct pci_dev, bus_list);
806 edev = pchild ? pci_dev_to_eeh_dev(pchild) : NULL;
807 pe = edev ? edev->pe : NULL;
808 if (pe) {
809 eeh_serialize_lock(&flags);
810 eeh_pe_mark_isolated(pe);
811 eeh_serialize_unlock(flags);
812 eeh_pe_set_option(pe, EEH_OPT_FREEZE_PE);
813 }
814 }
815
816 /*
817 * The PE is left in frozen state if the event is missed. It's
818 * fine as the PCI devices (PE) aren't functional any more.
819 */
820 event = kzalloc(sizeof(*event), GFP_ATOMIC);
821 if (!event) {
822 SLOT_WARN(php_slot,
823 "PCI slot [%s] missed hotplug event 0x%04x\n",
824 php_slot->name, sts);
825 return IRQ_HANDLED;
826 }
827
828 pci_info(pdev, "PCI slot [%s] %s (IRQ: %d)\n",
829 php_slot->name, added ? "added" : "removed", irq);
830 INIT_WORK(&event->work, pnv_php_event_handler);
831 event->added = added;
832 event->php_slot = php_slot;
833 queue_work(php_slot->wq, &event->work);
834
835 return IRQ_HANDLED;
836 }
837
pnv_php_init_irq(struct pnv_php_slot * php_slot,int irq)838 static void pnv_php_init_irq(struct pnv_php_slot *php_slot, int irq)
839 {
840 struct pci_dev *pdev = php_slot->pdev;
841 u32 broken_pdc = 0;
842 u16 sts, ctrl;
843 int ret;
844
845 /* Allocate workqueue */
846 php_slot->wq = alloc_workqueue("pciehp-%s", 0, 0, php_slot->name);
847 if (!php_slot->wq) {
848 SLOT_WARN(php_slot, "Cannot alloc workqueue\n");
849 pnv_php_disable_irq(php_slot, true);
850 return;
851 }
852
853 /* Check PDC (Presence Detection Change) is broken or not */
854 ret = of_property_read_u32(php_slot->dn, "ibm,slot-broken-pdc",
855 &broken_pdc);
856 if (!ret && broken_pdc)
857 php_slot->flags |= PNV_PHP_FLAG_BROKEN_PDC;
858
859 /* Clear pending interrupts */
860 pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &sts);
861 if (php_slot->flags & PNV_PHP_FLAG_BROKEN_PDC)
862 sts |= PCI_EXP_SLTSTA_DLLSC;
863 else
864 sts |= (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC);
865 pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, sts);
866
867 /* Request the interrupt */
868 ret = request_irq(irq, pnv_php_interrupt, IRQF_SHARED,
869 php_slot->name, php_slot);
870 if (ret) {
871 pnv_php_disable_irq(php_slot, true);
872 SLOT_WARN(php_slot, "Error %d enabling IRQ %d\n", ret, irq);
873 return;
874 }
875
876 /* Enable the interrupts */
877 pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &ctrl);
878 if (php_slot->flags & PNV_PHP_FLAG_BROKEN_PDC) {
879 ctrl &= ~PCI_EXP_SLTCTL_PDCE;
880 ctrl |= (PCI_EXP_SLTCTL_HPIE |
881 PCI_EXP_SLTCTL_DLLSCE);
882 } else {
883 ctrl |= (PCI_EXP_SLTCTL_HPIE |
884 PCI_EXP_SLTCTL_PDCE |
885 PCI_EXP_SLTCTL_DLLSCE);
886 }
887 pcie_capability_write_word(pdev, PCI_EXP_SLTCTL, ctrl);
888
889 /* The interrupt is initialized successfully when @irq is valid */
890 php_slot->irq = irq;
891 }
892
pnv_php_enable_irq(struct pnv_php_slot * php_slot)893 static void pnv_php_enable_irq(struct pnv_php_slot *php_slot)
894 {
895 struct pci_dev *pdev = php_slot->pdev;
896 int irq, ret;
897
898 /*
899 * The MSI/MSIx interrupt might have been occupied by other
900 * drivers. Don't populate the surprise hotplug capability
901 * in that case.
902 */
903 if (pci_dev_msi_enabled(pdev))
904 return;
905
906 ret = pci_enable_device(pdev);
907 if (ret) {
908 SLOT_WARN(php_slot, "Error %d enabling device\n", ret);
909 return;
910 }
911
912 pci_set_master(pdev);
913
914 /* Enable MSIx interrupt */
915 irq = pnv_php_enable_msix(php_slot);
916 if (irq > 0) {
917 pnv_php_init_irq(php_slot, irq);
918 return;
919 }
920
921 /*
922 * Use MSI if MSIx doesn't work. Fail back to legacy INTx
923 * if MSI doesn't work either
924 */
925 ret = pci_enable_msi(pdev);
926 if (!ret || pdev->irq) {
927 irq = pdev->irq;
928 pnv_php_init_irq(php_slot, irq);
929 }
930 }
931
pnv_php_register_one(struct device_node * dn)932 static int pnv_php_register_one(struct device_node *dn)
933 {
934 struct pnv_php_slot *php_slot;
935 u32 prop32;
936 int ret;
937
938 /* Check if it's hotpluggable slot */
939 ret = of_property_read_u32(dn, "ibm,slot-pluggable", &prop32);
940 if (ret || !prop32)
941 return -ENXIO;
942
943 ret = of_property_read_u32(dn, "ibm,reset-by-firmware", &prop32);
944 if (ret || !prop32)
945 return -ENXIO;
946
947 php_slot = pnv_php_alloc_slot(dn);
948 if (!php_slot)
949 return -ENODEV;
950
951 ret = pnv_php_register_slot(php_slot);
952 if (ret)
953 goto free_slot;
954
955 ret = pnv_php_enable(php_slot, false);
956 if (ret)
957 goto unregister_slot;
958
959 /* Enable interrupt if the slot supports surprise hotplug */
960 ret = of_property_read_u32(dn, "ibm,slot-surprise-pluggable", &prop32);
961 if (!ret && prop32)
962 pnv_php_enable_irq(php_slot);
963
964 return 0;
965
966 unregister_slot:
967 pnv_php_unregister_one(php_slot->dn);
968 free_slot:
969 pnv_php_put_slot(php_slot);
970 return ret;
971 }
972
pnv_php_register(struct device_node * dn)973 static void pnv_php_register(struct device_node *dn)
974 {
975 struct device_node *child;
976
977 /*
978 * The parent slots should be registered before their
979 * child slots.
980 */
981 for_each_child_of_node(dn, child) {
982 pnv_php_register_one(child);
983 pnv_php_register(child);
984 }
985 }
986
pnv_php_unregister_one(struct device_node * dn)987 static void pnv_php_unregister_one(struct device_node *dn)
988 {
989 struct pnv_php_slot *php_slot;
990
991 php_slot = pnv_php_find_slot(dn);
992 if (!php_slot)
993 return;
994
995 php_slot->state = PNV_PHP_STATE_OFFLINE;
996 pci_hp_deregister(&php_slot->slot);
997 pnv_php_release(php_slot);
998 pnv_php_put_slot(php_slot);
999 }
1000
pnv_php_unregister(struct device_node * dn)1001 static void pnv_php_unregister(struct device_node *dn)
1002 {
1003 struct device_node *child;
1004
1005 /* The child slots should go before their parent slots */
1006 for_each_child_of_node(dn, child) {
1007 pnv_php_unregister(child);
1008 pnv_php_unregister_one(child);
1009 }
1010 }
1011
pnv_php_init(void)1012 static int __init pnv_php_init(void)
1013 {
1014 struct device_node *dn;
1015
1016 pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
1017 for_each_compatible_node(dn, NULL, "ibm,ioda2-phb")
1018 pnv_php_register(dn);
1019
1020 for_each_compatible_node(dn, NULL, "ibm,ioda3-phb")
1021 pnv_php_register(dn);
1022
1023 for_each_compatible_node(dn, NULL, "ibm,ioda2-npu2-opencapi-phb")
1024 pnv_php_register_one(dn); /* slot directly under the PHB */
1025 return 0;
1026 }
1027
pnv_php_exit(void)1028 static void __exit pnv_php_exit(void)
1029 {
1030 struct device_node *dn;
1031
1032 for_each_compatible_node(dn, NULL, "ibm,ioda2-phb")
1033 pnv_php_unregister(dn);
1034
1035 for_each_compatible_node(dn, NULL, "ibm,ioda3-phb")
1036 pnv_php_unregister(dn);
1037
1038 for_each_compatible_node(dn, NULL, "ibm,ioda2-npu2-opencapi-phb")
1039 pnv_php_unregister_one(dn); /* slot directly under the PHB */
1040 }
1041
1042 module_init(pnv_php_init);
1043 module_exit(pnv_php_exit);
1044
1045 MODULE_VERSION(DRIVER_VERSION);
1046 MODULE_LICENSE("GPL v2");
1047 MODULE_AUTHOR(DRIVER_AUTHOR);
1048 MODULE_DESCRIPTION(DRIVER_DESC);
1049