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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/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 break;
225
226 ret = pnv_php_populate_changeset(ocs, child);
227 if (ret)
228 break;
229 }
230
231 return ret;
232}
233
234static void *pnv_php_add_one_pdn(struct device_node *dn, void *data)
235{
236 struct pci_controller *hose = (struct pci_controller *)data;
237 struct pci_dn *pdn;
238
239 pdn = pci_add_device_node_info(hose, dn);
240 if (!pdn)
241 return ERR_PTR(-ENOMEM);
242
243 return NULL;
244}
245
246static void pnv_php_add_pdns(struct pnv_php_slot *slot)
247{
248 struct pci_controller *hose = pci_bus_to_host(slot->bus);
249
250 pci_traverse_device_nodes(slot->dn, pnv_php_add_one_pdn, hose);
251}
252
253static int pnv_php_add_devtree(struct pnv_php_slot *php_slot)
254{
255 void *fdt, *fdt1, *dt;
256 int ret;
257
258 /* We don't know the FDT blob size. We try to get it through
259 * maximal memory chunk and then copy it to another chunk that
260 * fits the real size.
261 */
262 fdt1 = kzalloc(0x10000, GFP_KERNEL);
263 if (!fdt1) {
264 ret = -ENOMEM;
265 goto out;
266 }
267
268 ret = pnv_pci_get_device_tree(php_slot->dn->phandle, fdt1, 0x10000);
269 if (ret) {
270 pci_warn(php_slot->pdev, "Error %d getting FDT blob\n", ret);
271 goto free_fdt1;
272 }
273
274 fdt = kzalloc(fdt_totalsize(fdt1), GFP_KERNEL);
275 if (!fdt) {
276 ret = -ENOMEM;
277 goto free_fdt1;
278 }
279
280 /* Unflatten device tree blob */
281 memcpy(fdt, fdt1, fdt_totalsize(fdt1));
282 dt = of_fdt_unflatten_tree(fdt, php_slot->dn, NULL);
283 if (!dt) {
284 ret = -EINVAL;
285 pci_warn(php_slot->pdev, "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 pci_warn(php_slot->pdev, "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 pci_warn(php_slot->pdev, "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
314destroy_changeset:
315 of_changeset_destroy(&php_slot->ocs);
316free_dt:
317 kfree(dt);
318 php_slot->dn->child = NULL;
319free_fdt:
320 kfree(fdt);
321free_fdt1:
322 kfree(fdt1);
323out:
324 return ret;
325}
326
327int pnv_php_set_slot_power_state(struct hotplug_slot *slot,
328 uint8_t state)
329{
330 struct pnv_php_slot *php_slot = slot->private;
331 struct opal_msg msg;
332 int ret;
333
334 ret = pnv_pci_set_power_state(php_slot->id, state, &msg);
335 if (ret > 0) {
336 if (be64_to_cpu(msg.params[1]) != php_slot->dn->phandle ||
337 be64_to_cpu(msg.params[2]) != state ||
338 be64_to_cpu(msg.params[3]) != OPAL_SUCCESS) {
339 pci_warn(php_slot->pdev, "Wrong msg (%lld, %lld, %lld)\n",
340 be64_to_cpu(msg.params[1]),
341 be64_to_cpu(msg.params[2]),
342 be64_to_cpu(msg.params[3]));
343 return -ENOMSG;
344 }
345 } else if (ret < 0) {
346 pci_warn(php_slot->pdev, "Error %d powering %s\n",
347 ret, (state == OPAL_PCI_SLOT_POWER_ON) ? "on" : "off");
348 return ret;
349 }
350
351 if (state == OPAL_PCI_SLOT_POWER_OFF || state == OPAL_PCI_SLOT_OFFLINE)
352 pnv_php_rmv_devtree(php_slot);
353 else
354 ret = pnv_php_add_devtree(php_slot);
355
356 return ret;
357}
358EXPORT_SYMBOL_GPL(pnv_php_set_slot_power_state);
359
360static int pnv_php_get_power_state(struct hotplug_slot *slot, u8 *state)
361{
362 struct pnv_php_slot *php_slot = slot->private;
363 uint8_t power_state = OPAL_PCI_SLOT_POWER_ON;
364 int ret;
365
366 /*
367 * Retrieve power status from firmware. If we fail
368 * getting that, the power status fails back to
369 * be on.
370 */
371 ret = pnv_pci_get_power_state(php_slot->id, &power_state);
372 if (ret) {
373 pci_warn(php_slot->pdev, "Error %d getting power status\n",
374 ret);
375 } else {
376 *state = power_state;
377 slot->info->power_status = power_state;
378 }
379
380 return 0;
381}
382
383static int pnv_php_get_adapter_state(struct hotplug_slot *slot, u8 *state)
384{
385 struct pnv_php_slot *php_slot = slot->private;
386 uint8_t presence = OPAL_PCI_SLOT_EMPTY;
387 int ret;
388
389 /*
390 * Retrieve presence status from firmware. If we can't
391 * get that, it will fail back to be empty.
392 */
393 ret = pnv_pci_get_presence_state(php_slot->id, &presence);
394 if (ret >= 0) {
395 *state = presence;
396 slot->info->adapter_status = presence;
397 ret = 0;
398 } else {
399 pci_warn(php_slot->pdev, "Error %d getting presence\n", ret);
400 }
401
402 return ret;
403}
404
405static int pnv_php_set_attention_state(struct hotplug_slot *slot, u8 state)
406{
407 /* FIXME: Make it real once firmware supports it */
408 slot->info->attention_status = state;
409
410 return 0;
411}
412
413static int pnv_php_enable(struct pnv_php_slot *php_slot, bool rescan)
414{
415 struct hotplug_slot *slot = &php_slot->slot;
416 uint8_t presence = OPAL_PCI_SLOT_EMPTY;
417 uint8_t power_status = OPAL_PCI_SLOT_POWER_ON;
418 int ret;
419
420 /* Check if the slot has been configured */
421 if (php_slot->state != PNV_PHP_STATE_REGISTERED)
422 return 0;
423
424 /* Retrieve slot presence status */
425 ret = pnv_php_get_adapter_state(slot, &presence);
426 if (ret)
427 return ret;
428
429 /*
430 * Proceed if there have nothing behind the slot. However,
431 * we should leave the slot in registered state at the
432 * beginning. Otherwise, the PCI devices inserted afterwards
433 * won't be probed and populated.
434 */
435 if (presence == OPAL_PCI_SLOT_EMPTY) {
436 if (!php_slot->power_state_check) {
437 php_slot->power_state_check = true;
438
439 return 0;
440 }
441
442 goto scan;
443 }
444
445 /*
446 * If the power supply to the slot is off, we can't detect
447 * adapter presence state. That means we have to turn the
448 * slot on before going to probe slot's presence state.
449 *
450 * On the first time, we don't change the power status to
451 * boost system boot with assumption that the firmware
452 * supplies consistent slot power status: empty slot always
453 * has its power off and non-empty slot has its power on.
454 */
455 if (!php_slot->power_state_check) {
456 php_slot->power_state_check = true;
457
458 ret = pnv_php_get_power_state(slot, &power_status);
459 if (ret)
460 return ret;
461
462 if (power_status != OPAL_PCI_SLOT_POWER_ON)
463 return 0;
464 }
465
466 /* Check the power status. Scan the slot if it is already on */
467 ret = pnv_php_get_power_state(slot, &power_status);
468 if (ret)
469 return ret;
470
471 if (power_status == OPAL_PCI_SLOT_POWER_ON)
472 goto scan;
473
474 /* Power is off, turn it on and then scan the slot */
475 ret = pnv_php_set_slot_power_state(slot, OPAL_PCI_SLOT_POWER_ON);
476 if (ret)
477 return ret;
478
479scan:
480 if (presence == OPAL_PCI_SLOT_PRESENT) {
481 if (rescan) {
482 pci_lock_rescan_remove();
483 pci_hp_add_devices(php_slot->bus);
484 pci_unlock_rescan_remove();
485 }
486
487 /* Rescan for child hotpluggable slots */
488 php_slot->state = PNV_PHP_STATE_POPULATED;
489 if (rescan)
490 pnv_php_register(php_slot->dn);
491 } else {
492 php_slot->state = PNV_PHP_STATE_POPULATED;
493 }
494
495 return 0;
496}
497
498static int pnv_php_enable_slot(struct hotplug_slot *slot)
499{
500 struct pnv_php_slot *php_slot = container_of(slot,
501 struct pnv_php_slot, slot);
502
503 return pnv_php_enable(php_slot, true);
504}
505
506static int pnv_php_disable_slot(struct hotplug_slot *slot)
507{
508 struct pnv_php_slot *php_slot = slot->private;
509 int ret;
510
511 if (php_slot->state != PNV_PHP_STATE_POPULATED)
512 return 0;
513
514 /* Remove all devices behind the slot */
515 pci_lock_rescan_remove();
516 pci_hp_remove_devices(php_slot->bus);
517 pci_unlock_rescan_remove();
518
519 /* Detach the child hotpluggable slots */
520 pnv_php_unregister(php_slot->dn);
521
522 /* Notify firmware and remove device nodes */
523 ret = pnv_php_set_slot_power_state(slot, OPAL_PCI_SLOT_POWER_OFF);
524
525 php_slot->state = PNV_PHP_STATE_REGISTERED;
526 return ret;
527}
528
529static struct hotplug_slot_ops php_slot_ops = {
530 .get_power_status = pnv_php_get_power_state,
531 .get_adapter_status = pnv_php_get_adapter_state,
532 .set_attention_status = pnv_php_set_attention_state,
533 .enable_slot = pnv_php_enable_slot,
534 .disable_slot = pnv_php_disable_slot,
535};
536
537static void pnv_php_release(struct hotplug_slot *slot)
538{
539 struct pnv_php_slot *php_slot = slot->private;
540 unsigned long flags;
541
542 /* Remove from global or child list */
543 spin_lock_irqsave(&pnv_php_lock, flags);
544 list_del(&php_slot->link);
545 spin_unlock_irqrestore(&pnv_php_lock, flags);
546
547 /* Detach from parent */
548 pnv_php_put_slot(php_slot);
549 pnv_php_put_slot(php_slot->parent);
550}
551
552static struct pnv_php_slot *pnv_php_alloc_slot(struct device_node *dn)
553{
554 struct pnv_php_slot *php_slot;
555 struct pci_bus *bus;
556 const char *label;
557 uint64_t id;
558 int ret;
559
560 ret = of_property_read_string(dn, "ibm,slot-label", &label);
561 if (ret)
562 return NULL;
563
564 if (pnv_pci_get_slot_id(dn, &id))
565 return NULL;
566
567 bus = pci_find_bus_by_node(dn);
568 if (!bus)
569 return NULL;
570
571 php_slot = kzalloc(sizeof(*php_slot), GFP_KERNEL);
572 if (!php_slot)
573 return NULL;
574
575 php_slot->name = kstrdup(label, GFP_KERNEL);
576 if (!php_slot->name) {
577 kfree(php_slot);
578 return NULL;
579 }
580
581 if (dn->child && PCI_DN(dn->child))
582 php_slot->slot_no = PCI_SLOT(PCI_DN(dn->child)->devfn);
583 else
584 php_slot->slot_no = -1; /* Placeholder slot */
585
586 kref_init(&php_slot->kref);
587 php_slot->state = PNV_PHP_STATE_INITIALIZED;
588 php_slot->dn = dn;
589 php_slot->pdev = bus->self;
590 php_slot->bus = bus;
591 php_slot->id = id;
592 php_slot->power_state_check = false;
593 php_slot->slot.ops = &php_slot_ops;
594 php_slot->slot.info = &php_slot->slot_info;
595 php_slot->slot.release = pnv_php_release;
596 php_slot->slot.private = php_slot;
597
598 INIT_LIST_HEAD(&php_slot->children);
599 INIT_LIST_HEAD(&php_slot->link);
600
601 return php_slot;
602}
603
604static int pnv_php_register_slot(struct pnv_php_slot *php_slot)
605{
606 struct pnv_php_slot *parent;
607 struct device_node *dn = php_slot->dn;
608 unsigned long flags;
609 int ret;
610
611 /* Check if the slot is registered or not */
612 parent = pnv_php_find_slot(php_slot->dn);
613 if (parent) {
614 pnv_php_put_slot(parent);
615 return -EEXIST;
616 }
617
618 /* Register PCI slot */
619 ret = pci_hp_register(&php_slot->slot, php_slot->bus,
620 php_slot->slot_no, php_slot->name);
621 if (ret) {
622 pci_warn(php_slot->pdev, "Error %d registering slot\n", ret);
623 return ret;
624 }
625
626 /* Attach to the parent's child list or global list */
627 while ((dn = of_get_parent(dn))) {
628 if (!PCI_DN(dn)) {
629 of_node_put(dn);
630 break;
631 }
632
633 parent = pnv_php_find_slot(dn);
634 if (parent) {
635 of_node_put(dn);
636 break;
637 }
638
639 of_node_put(dn);
640 }
641
642 spin_lock_irqsave(&pnv_php_lock, flags);
643 php_slot->parent = parent;
644 if (parent)
645 list_add_tail(&php_slot->link, &parent->children);
646 else
647 list_add_tail(&php_slot->link, &pnv_php_slot_list);
648 spin_unlock_irqrestore(&pnv_php_lock, flags);
649
650 php_slot->state = PNV_PHP_STATE_REGISTERED;
651 return 0;
652}
653
654static int pnv_php_enable_msix(struct pnv_php_slot *php_slot)
655{
656 struct pci_dev *pdev = php_slot->pdev;
657 struct msix_entry entry;
658 int nr_entries, ret;
659 u16 pcie_flag;
660
661 /* Get total number of MSIx entries */
662 nr_entries = pci_msix_vec_count(pdev);
663 if (nr_entries < 0)
664 return nr_entries;
665
666 /* Check hotplug MSIx entry is in range */
667 pcie_capability_read_word(pdev, PCI_EXP_FLAGS, &pcie_flag);
668 entry.entry = (pcie_flag & PCI_EXP_FLAGS_IRQ) >> 9;
669 if (entry.entry >= nr_entries)
670 return -ERANGE;
671
672 /* Enable MSIx */
673 ret = pci_enable_msix_exact(pdev, &entry, 1);
674 if (ret) {
675 pci_warn(pdev, "Error %d enabling MSIx\n", ret);
676 return ret;
677 }
678
679 return entry.vector;
680}
681
682static void pnv_php_event_handler(struct work_struct *work)
683{
684 struct pnv_php_event *event =
685 container_of(work, struct pnv_php_event, work);
686 struct pnv_php_slot *php_slot = event->php_slot;
687
688 if (event->added)
689 pnv_php_enable_slot(&php_slot->slot);
690 else
691 pnv_php_disable_slot(&php_slot->slot);
692
693 kfree(event);
694}
695
696static irqreturn_t pnv_php_interrupt(int irq, void *data)
697{
698 struct pnv_php_slot *php_slot = data;
699 struct pci_dev *pchild, *pdev = php_slot->pdev;
700 struct eeh_dev *edev;
701 struct eeh_pe *pe;
702 struct pnv_php_event *event;
703 u16 sts, lsts;
704 u8 presence;
705 bool added;
706 unsigned long flags;
707 int ret;
708
709 pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &sts);
710 sts &= (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC);
711 pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, sts);
712 if (sts & PCI_EXP_SLTSTA_DLLSC) {
713 pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lsts);
714 added = !!(lsts & PCI_EXP_LNKSTA_DLLLA);
715 } else if (!(php_slot->flags & PNV_PHP_FLAG_BROKEN_PDC) &&
716 (sts & PCI_EXP_SLTSTA_PDC)) {
717 ret = pnv_pci_get_presence_state(php_slot->id, &presence);
718 if (ret) {
719 pci_warn(pdev, "PCI slot [%s] error %d getting presence (0x%04x), to retry the operation.\n",
720 php_slot->name, ret, sts);
721 return IRQ_HANDLED;
722 }
723
724 added = !!(presence == OPAL_PCI_SLOT_PRESENT);
725 } else {
726 return IRQ_NONE;
727 }
728
729 /* Freeze the removed PE to avoid unexpected error reporting */
730 if (!added) {
731 pchild = list_first_entry_or_null(&php_slot->bus->devices,
732 struct pci_dev, bus_list);
733 edev = pchild ? pci_dev_to_eeh_dev(pchild) : NULL;
734 pe = edev ? edev->pe : NULL;
735 if (pe) {
736 eeh_serialize_lock(&flags);
737 eeh_pe_state_mark(pe, EEH_PE_ISOLATED);
738 eeh_serialize_unlock(flags);
739 eeh_pe_set_option(pe, EEH_OPT_FREEZE_PE);
740 }
741 }
742
743 /*
744 * The PE is left in frozen state if the event is missed. It's
745 * fine as the PCI devices (PE) aren't functional any more.
746 */
747 event = kzalloc(sizeof(*event), GFP_ATOMIC);
748 if (!event) {
749 pci_warn(pdev, "PCI slot [%s] missed hotplug event 0x%04x\n",
750 php_slot->name, sts);
751 return IRQ_HANDLED;
752 }
753
754 pci_info(pdev, "PCI slot [%s] %s (IRQ: %d)\n",
755 php_slot->name, added ? "added" : "removed", irq);
756 INIT_WORK(&event->work, pnv_php_event_handler);
757 event->added = added;
758 event->php_slot = php_slot;
759 queue_work(php_slot->wq, &event->work);
760
761 return IRQ_HANDLED;
762}
763
764static void pnv_php_init_irq(struct pnv_php_slot *php_slot, int irq)
765{
766 struct pci_dev *pdev = php_slot->pdev;
767 u32 broken_pdc = 0;
768 u16 sts, ctrl;
769 int ret;
770
771 /* Allocate workqueue */
772 php_slot->wq = alloc_workqueue("pciehp-%s", 0, 0, php_slot->name);
773 if (!php_slot->wq) {
774 pci_warn(pdev, "Cannot alloc workqueue\n");
775 pnv_php_disable_irq(php_slot, true);
776 return;
777 }
778
779 /* Check PDC (Presence Detection Change) is broken or not */
780 ret = of_property_read_u32(php_slot->dn, "ibm,slot-broken-pdc",
781 &broken_pdc);
782 if (!ret && broken_pdc)
783 php_slot->flags |= PNV_PHP_FLAG_BROKEN_PDC;
784
785 /* Clear pending interrupts */
786 pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &sts);
787 if (php_slot->flags & PNV_PHP_FLAG_BROKEN_PDC)
788 sts |= PCI_EXP_SLTSTA_DLLSC;
789 else
790 sts |= (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC);
791 pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, sts);
792
793 /* Request the interrupt */
794 ret = request_irq(irq, pnv_php_interrupt, IRQF_SHARED,
795 php_slot->name, php_slot);
796 if (ret) {
797 pnv_php_disable_irq(php_slot, true);
798 pci_warn(pdev, "Error %d enabling IRQ %d\n", ret, irq);
799 return;
800 }
801
802 /* Enable the interrupts */
803 pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &ctrl);
804 if (php_slot->flags & PNV_PHP_FLAG_BROKEN_PDC) {
805 ctrl &= ~PCI_EXP_SLTCTL_PDCE;
806 ctrl |= (PCI_EXP_SLTCTL_HPIE |
807 PCI_EXP_SLTCTL_DLLSCE);
808 } else {
809 ctrl |= (PCI_EXP_SLTCTL_HPIE |
810 PCI_EXP_SLTCTL_PDCE |
811 PCI_EXP_SLTCTL_DLLSCE);
812 }
813 pcie_capability_write_word(pdev, PCI_EXP_SLTCTL, ctrl);
814
815 /* The interrupt is initialized successfully when @irq is valid */
816 php_slot->irq = irq;
817}
818
819static void pnv_php_enable_irq(struct pnv_php_slot *php_slot)
820{
821 struct pci_dev *pdev = php_slot->pdev;
822 int irq, ret;
823
824 /*
825 * The MSI/MSIx interrupt might have been occupied by other
826 * drivers. Don't populate the surprise hotplug capability
827 * in that case.
828 */
829 if (pci_dev_msi_enabled(pdev))
830 return;
831
832 ret = pci_enable_device(pdev);
833 if (ret) {
834 pci_warn(pdev, "Error %d enabling device\n", ret);
835 return;
836 }
837
838 pci_set_master(pdev);
839
840 /* Enable MSIx interrupt */
841 irq = pnv_php_enable_msix(php_slot);
842 if (irq > 0) {
843 pnv_php_init_irq(php_slot, irq);
844 return;
845 }
846
847 /*
848 * Use MSI if MSIx doesn't work. Fail back to legacy INTx
849 * if MSI doesn't work either
850 */
851 ret = pci_enable_msi(pdev);
852 if (!ret || pdev->irq) {
853 irq = pdev->irq;
854 pnv_php_init_irq(php_slot, irq);
855 }
856}
857
858static int pnv_php_register_one(struct device_node *dn)
859{
860 struct pnv_php_slot *php_slot;
861 u32 prop32;
862 int ret;
863
864 /* Check if it's hotpluggable slot */
865 ret = of_property_read_u32(dn, "ibm,slot-pluggable", &prop32);
866 if (ret || !prop32)
867 return -ENXIO;
868
869 ret = of_property_read_u32(dn, "ibm,reset-by-firmware", &prop32);
870 if (ret || !prop32)
871 return -ENXIO;
872
873 php_slot = pnv_php_alloc_slot(dn);
874 if (!php_slot)
875 return -ENODEV;
876
877 ret = pnv_php_register_slot(php_slot);
878 if (ret)
879 goto free_slot;
880
881 ret = pnv_php_enable(php_slot, false);
882 if (ret)
883 goto unregister_slot;
884
885 /* Enable interrupt if the slot supports surprise hotplug */
886 ret = of_property_read_u32(dn, "ibm,slot-surprise-pluggable", &prop32);
887 if (!ret && prop32)
888 pnv_php_enable_irq(php_slot);
889
890 return 0;
891
892unregister_slot:
893 pnv_php_unregister_one(php_slot->dn);
894free_slot:
895 pnv_php_put_slot(php_slot);
896 return ret;
897}
898
899static void pnv_php_register(struct device_node *dn)
900{
901 struct device_node *child;
902
903 /*
904 * The parent slots should be registered before their
905 * child slots.
906 */
907 for_each_child_of_node(dn, child) {
908 pnv_php_register_one(child);
909 pnv_php_register(child);
910 }
911}
912
913static void pnv_php_unregister_one(struct device_node *dn)
914{
915 struct pnv_php_slot *php_slot;
916
917 php_slot = pnv_php_find_slot(dn);
918 if (!php_slot)
919 return;
920
921 php_slot->state = PNV_PHP_STATE_OFFLINE;
922 pci_hp_deregister(&php_slot->slot);
923 pnv_php_put_slot(php_slot);
924}
925
926static void pnv_php_unregister(struct device_node *dn)
927{
928 struct device_node *child;
929
930 /* The child slots should go before their parent slots */
931 for_each_child_of_node(dn, child) {
932 pnv_php_unregister(child);
933 pnv_php_unregister_one(child);
934 }
935}
936
937static int __init pnv_php_init(void)
938{
939 struct device_node *dn;
940
941 pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
942 for_each_compatible_node(dn, NULL, "ibm,ioda2-phb")
943 pnv_php_register(dn);
944
945 return 0;
946}
947
948static void __exit pnv_php_exit(void)
949{
950 struct device_node *dn;
951
952 for_each_compatible_node(dn, NULL, "ibm,ioda2-phb")
953 pnv_php_unregister(dn);
954}
955
956module_init(pnv_php_init);
957module_exit(pnv_php_exit);
958
959MODULE_VERSION(DRIVER_VERSION);
960MODULE_LICENSE("GPL v2");
961MODULE_AUTHOR(DRIVER_AUTHOR);
962MODULE_DESCRIPTION(DRIVER_DESC);