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