1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2006 Jake Moilanen <moilanen@austin.ibm.com>, IBM Corp.
4 * Copyright 2006-2007 Michael Ellerman, IBM Corp.
5 */
6
7#include <linux/crash_dump.h>
8#include <linux/device.h>
9#include <linux/irq.h>
10#include <linux/irqdomain.h>
11#include <linux/msi.h>
12
13#include <asm/rtas.h>
14#include <asm/hw_irq.h>
15#include <asm/ppc-pci.h>
16#include <asm/machdep.h>
17#include <asm/xive.h>
18
19#include "pseries.h"
20
21static int query_token, change_token;
22
23#define RTAS_QUERY_FN 0
24#define RTAS_CHANGE_FN 1
25#define RTAS_RESET_FN 2
26#define RTAS_CHANGE_MSI_FN 3
27#define RTAS_CHANGE_MSIX_FN 4
28#define RTAS_CHANGE_32MSI_FN 5
29#define RTAS_CHANGE_32MSIX_FN 6
30
31/* RTAS Helpers */
32
33static int rtas_change_msi(struct pci_dn *pdn, u32 func, u32 num_irqs)
34{
35 u32 addr, seq_num, rtas_ret[3];
36 unsigned long buid;
37 int rc;
38
39 addr = rtas_config_addr(pdn->busno, pdn->devfn, 0);
40 buid = pdn->phb->buid;
41
42 seq_num = 1;
43 do {
44 if (func == RTAS_CHANGE_MSI_FN || func == RTAS_CHANGE_MSIX_FN ||
45 func == RTAS_CHANGE_32MSI_FN || func == RTAS_CHANGE_32MSIX_FN)
46 rc = rtas_call(change_token, 6, 4, rtas_ret, addr,
47 BUID_HI(buid), BUID_LO(buid),
48 func, num_irqs, seq_num);
49 else
50 rc = rtas_call(change_token, 6, 3, rtas_ret, addr,
51 BUID_HI(buid), BUID_LO(buid),
52 func, num_irqs, seq_num);
53
54 seq_num = rtas_ret[1];
55 } while (rtas_busy_delay(rc));
56
57 /*
58 * If the RTAS call succeeded, return the number of irqs allocated.
59 * If not, make sure we return a negative error code.
60 */
61 if (rc == 0)
62 rc = rtas_ret[0];
63 else if (rc > 0)
64 rc = -rc;
65
66 pr_debug("rtas_msi: ibm,change_msi(func=%d,num=%d), got %d rc = %d\n",
67 func, num_irqs, rtas_ret[0], rc);
68
69 return rc;
70}
71
72static void rtas_disable_msi(struct pci_dev *pdev)
73{
74 struct pci_dn *pdn;
75
76 pdn = pci_get_pdn(pdev);
77 if (!pdn)
78 return;
79
80 /*
81 * disabling MSI with the explicit interface also disables MSI-X
82 */
83 if (rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, num_irqs: 0) != 0) {
84 /*
85 * may have failed because explicit interface is not
86 * present
87 */
88 if (rtas_change_msi(pdn, RTAS_CHANGE_FN, num_irqs: 0) != 0) {
89 pr_debug("rtas_msi: Setting MSIs to 0 failed!\n");
90 }
91 }
92}
93
94static int rtas_query_irq_number(struct pci_dn *pdn, int offset)
95{
96 u32 addr, rtas_ret[2];
97 unsigned long buid;
98 int rc;
99
100 addr = rtas_config_addr(pdn->busno, pdn->devfn, 0);
101 buid = pdn->phb->buid;
102
103 do {
104 rc = rtas_call(query_token, 4, 3, rtas_ret, addr,
105 BUID_HI(buid), BUID_LO(buid), offset);
106 } while (rtas_busy_delay(rc));
107
108 if (rc) {
109 pr_debug("rtas_msi: error (%d) querying source number\n", rc);
110 return rc;
111 }
112
113 return rtas_ret[0];
114}
115
116static int check_req(struct pci_dev *pdev, int nvec, char *prop_name)
117{
118 struct device_node *dn;
119 const __be32 *p;
120 u32 req_msi;
121
122 dn = pci_device_to_OF_node(pdev);
123
124 p = of_get_property(node: dn, name: prop_name, NULL);
125 if (!p) {
126 pr_debug("rtas_msi: No %s on %pOF\n", prop_name, dn);
127 return -ENOENT;
128 }
129
130 req_msi = be32_to_cpup(p);
131 if (req_msi < nvec) {
132 pr_debug("rtas_msi: %s requests < %d MSIs\n", prop_name, nvec);
133
134 if (req_msi == 0) /* Be paranoid */
135 return -ENOSPC;
136
137 return req_msi;
138 }
139
140 return 0;
141}
142
143static int check_req_msi(struct pci_dev *pdev, int nvec)
144{
145 return check_req(pdev, nvec, prop_name: "ibm,req#msi");
146}
147
148static int check_req_msix(struct pci_dev *pdev, int nvec)
149{
150 return check_req(pdev, nvec, prop_name: "ibm,req#msi-x");
151}
152
153/* Quota calculation */
154
155static struct device_node *__find_pe_total_msi(struct device_node *node, int *total)
156{
157 struct device_node *dn;
158 const __be32 *p;
159
160 dn = of_node_get(node);
161 while (dn) {
162 p = of_get_property(node: dn, name: "ibm,pe-total-#msi", NULL);
163 if (p) {
164 pr_debug("rtas_msi: found prop on dn %pOF\n",
165 dn);
166 *total = be32_to_cpup(p);
167 return dn;
168 }
169
170 dn = of_get_next_parent(node: dn);
171 }
172
173 return NULL;
174}
175
176static struct device_node *find_pe_total_msi(struct pci_dev *dev, int *total)
177{
178 return __find_pe_total_msi(node: pci_device_to_OF_node(dev), total);
179}
180
181static struct device_node *find_pe_dn(struct pci_dev *dev, int *total)
182{
183 struct device_node *dn;
184 struct eeh_dev *edev;
185
186 /* Found our PE and assume 8 at that point. */
187
188 dn = pci_device_to_OF_node(dev);
189 if (!dn)
190 return NULL;
191
192 /* Get the top level device in the PE */
193 edev = pdn_to_eeh_dev(PCI_DN(dn));
194 if (edev->pe)
195 edev = list_first_entry(&edev->pe->edevs, struct eeh_dev,
196 entry);
197 dn = pci_device_to_OF_node(edev->pdev);
198 if (!dn)
199 return NULL;
200
201 /* We actually want the parent */
202 dn = of_get_parent(node: dn);
203 if (!dn)
204 return NULL;
205
206 /* Hardcode of 8 for old firmwares */
207 *total = 8;
208 pr_debug("rtas_msi: using PE dn %pOF\n", dn);
209
210 return dn;
211}
212
213struct msi_counts {
214 struct device_node *requestor;
215 int num_devices;
216 int request;
217 int quota;
218 int spare;
219 int over_quota;
220};
221
222static void *count_non_bridge_devices(struct device_node *dn, void *data)
223{
224 struct msi_counts *counts = data;
225 const __be32 *p;
226 u32 class;
227
228 pr_debug("rtas_msi: counting %pOF\n", dn);
229
230 p = of_get_property(node: dn, name: "class-code", NULL);
231 class = p ? be32_to_cpup(p) : 0;
232
233 if ((class >> 8) != PCI_CLASS_BRIDGE_PCI)
234 counts->num_devices++;
235
236 return NULL;
237}
238
239static void *count_spare_msis(struct device_node *dn, void *data)
240{
241 struct msi_counts *counts = data;
242 const __be32 *p;
243 int req;
244
245 if (dn == counts->requestor)
246 req = counts->request;
247 else {
248 /* We don't know if a driver will try to use MSI or MSI-X,
249 * so we just have to punt and use the larger of the two. */
250 req = 0;
251 p = of_get_property(node: dn, name: "ibm,req#msi", NULL);
252 if (p)
253 req = be32_to_cpup(p);
254
255 p = of_get_property(node: dn, name: "ibm,req#msi-x", NULL);
256 if (p)
257 req = max(req, (int)be32_to_cpup(p));
258 }
259
260 if (req < counts->quota)
261 counts->spare += counts->quota - req;
262 else if (req > counts->quota)
263 counts->over_quota++;
264
265 return NULL;
266}
267
268static int msi_quota_for_device(struct pci_dev *dev, int request)
269{
270 struct device_node *pe_dn;
271 struct msi_counts counts;
272 int total;
273
274 pr_debug("rtas_msi: calc quota for %s, request %d\n", pci_name(dev),
275 request);
276
277 pe_dn = find_pe_total_msi(dev, total: &total);
278 if (!pe_dn)
279 pe_dn = find_pe_dn(dev, total: &total);
280
281 if (!pe_dn) {
282 pr_err("rtas_msi: couldn't find PE for %s\n", pci_name(dev));
283 goto out;
284 }
285
286 pr_debug("rtas_msi: found PE %pOF\n", pe_dn);
287
288 memset(&counts, 0, sizeof(struct msi_counts));
289
290 /* Work out how many devices we have below this PE */
291 pci_traverse_device_nodes(pe_dn, count_non_bridge_devices, &counts);
292
293 if (counts.num_devices == 0) {
294 pr_err("rtas_msi: found 0 devices under PE for %s\n",
295 pci_name(dev));
296 goto out;
297 }
298
299 counts.quota = total / counts.num_devices;
300 if (request <= counts.quota)
301 goto out;
302
303 /* else, we have some more calculating to do */
304 counts.requestor = pci_device_to_OF_node(dev);
305 counts.request = request;
306 pci_traverse_device_nodes(pe_dn, count_spare_msis, &counts);
307
308 /* If the quota isn't an integer multiple of the total, we can
309 * use the remainder as spare MSIs for anyone that wants them. */
310 counts.spare += total % counts.num_devices;
311
312 /* Divide any spare by the number of over-quota requestors */
313 if (counts.over_quota)
314 counts.quota += counts.spare / counts.over_quota;
315
316 /* And finally clamp the request to the possibly adjusted quota */
317 request = min(counts.quota, request);
318
319 pr_debug("rtas_msi: request clamped to quota %d\n", request);
320out:
321 of_node_put(node: pe_dn);
322
323 return request;
324}
325
326static void rtas_hack_32bit_msi_gen2(struct pci_dev *pdev)
327{
328 u32 addr_hi, addr_lo;
329
330 /*
331 * We should only get in here for IODA1 configs. This is based on the
332 * fact that we using RTAS for MSIs, we don't have the 32 bit MSI RTAS
333 * support, and we are in a PCIe Gen2 slot.
334 */
335 dev_info(&pdev->dev,
336 "rtas_msi: No 32 bit MSI firmware support, forcing 32 bit MSI\n");
337 pci_read_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, &addr_hi);
338 addr_lo = 0xffff0000 | ((addr_hi >> (48 - 32)) << 4);
339 pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_LO, addr_lo);
340 pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, 0);
341}
342
343static int rtas_prepare_msi_irqs(struct pci_dev *pdev, int nvec_in, int type,
344 msi_alloc_info_t *arg)
345{
346 struct pci_dn *pdn;
347 int quota, rc;
348 int nvec = nvec_in;
349 int use_32bit_msi_hack = 0;
350
351 if (type == PCI_CAP_ID_MSIX)
352 rc = check_req_msix(pdev, nvec);
353 else
354 rc = check_req_msi(pdev, nvec);
355
356 if (rc)
357 return rc;
358
359 quota = msi_quota_for_device(dev: pdev, request: nvec);
360
361 if (quota && quota < nvec)
362 return quota;
363
364 /*
365 * Firmware currently refuse any non power of two allocation
366 * so we round up if the quota will allow it.
367 */
368 if (type == PCI_CAP_ID_MSIX) {
369 int m = roundup_pow_of_two(nvec);
370 quota = msi_quota_for_device(dev: pdev, request: m);
371
372 if (quota >= m)
373 nvec = m;
374 }
375
376 pdn = pci_get_pdn(pdev);
377
378 /*
379 * Try the new more explicit firmware interface, if that fails fall
380 * back to the old interface. The old interface is known to never
381 * return MSI-Xs.
382 */
383again:
384 if (type == PCI_CAP_ID_MSI) {
385 if (pdev->no_64bit_msi) {
386 rc = rtas_change_msi(pdn, RTAS_CHANGE_32MSI_FN, num_irqs: nvec);
387 if (rc < 0) {
388 /*
389 * We only want to run the 32 bit MSI hack below if
390 * the max bus speed is Gen2 speed
391 */
392 if (pdev->bus->max_bus_speed != PCIE_SPEED_5_0GT)
393 return rc;
394
395 use_32bit_msi_hack = 1;
396 }
397 } else
398 rc = -1;
399
400 if (rc < 0)
401 rc = rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, num_irqs: nvec);
402
403 if (rc < 0) {
404 pr_debug("rtas_msi: trying the old firmware call.\n");
405 rc = rtas_change_msi(pdn, RTAS_CHANGE_FN, num_irqs: nvec);
406 }
407
408 if (use_32bit_msi_hack && rc > 0)
409 rtas_hack_32bit_msi_gen2(pdev);
410 } else {
411 if (pdev->no_64bit_msi)
412 rc = rtas_change_msi(pdn, RTAS_CHANGE_32MSIX_FN, num_irqs: nvec);
413 else
414 rc = rtas_change_msi(pdn, RTAS_CHANGE_MSIX_FN, num_irqs: nvec);
415 }
416
417 if (rc != nvec) {
418 if (nvec != nvec_in) {
419 nvec = nvec_in;
420 goto again;
421 }
422 pr_debug("rtas_msi: rtas_change_msi() failed\n");
423 return rc;
424 }
425
426 return 0;
427}
428
429static int pseries_msi_ops_prepare(struct irq_domain *domain, struct device *dev,
430 int nvec, msi_alloc_info_t *arg)
431{
432 struct pci_dev *pdev = to_pci_dev(dev);
433 int type = pdev->msix_enabled ? PCI_CAP_ID_MSIX : PCI_CAP_ID_MSI;
434
435 return rtas_prepare_msi_irqs(pdev, nvec_in: nvec, type, arg);
436}
437
438/*
439 * ->msi_free() is called before irq_domain_free_irqs_top() when the
440 * handler data is still available. Use that to clear the XIVE
441 * controller data.
442 */
443static void pseries_msi_ops_msi_free(struct irq_domain *domain,
444 struct msi_domain_info *info,
445 unsigned int irq)
446{
447 if (xive_enabled())
448 xive_irq_free_data(irq);
449}
450
451/*
452 * RTAS can not disable one MSI at a time. It's all or nothing. Do it
453 * at the end after all IRQs have been freed.
454 */
455static void pseries_msi_post_free(struct irq_domain *domain, struct device *dev)
456{
457 if (WARN_ON_ONCE(!dev_is_pci(dev)))
458 return;
459
460 rtas_disable_msi(pdev: to_pci_dev(dev));
461}
462
463static struct msi_domain_ops pseries_pci_msi_domain_ops = {
464 .msi_prepare = pseries_msi_ops_prepare,
465 .msi_free = pseries_msi_ops_msi_free,
466 .msi_post_free = pseries_msi_post_free,
467};
468
469static void pseries_msi_shutdown(struct irq_data *d)
470{
471 d = d->parent_data;
472 if (d->chip->irq_shutdown)
473 d->chip->irq_shutdown(d);
474}
475
476static void pseries_msi_mask(struct irq_data *d)
477{
478 pci_msi_mask_irq(data: d);
479 irq_chip_mask_parent(data: d);
480}
481
482static void pseries_msi_unmask(struct irq_data *d)
483{
484 pci_msi_unmask_irq(data: d);
485 irq_chip_unmask_parent(data: d);
486}
487
488static void pseries_msi_write_msg(struct irq_data *data, struct msi_msg *msg)
489{
490 struct msi_desc *entry = irq_data_get_msi_desc(d: data);
491
492 /*
493 * Do not update the MSIx vector table. It's not strictly necessary
494 * because the table is initialized by the underlying hypervisor, PowerVM
495 * or QEMU/KVM. However, if the MSIx vector entry is cleared, any further
496 * activation will fail. This can happen in some drivers (eg. IPR) which
497 * deactivate an IRQ used for testing MSI support.
498 */
499 entry->msg = *msg;
500}
501
502static struct irq_chip pseries_pci_msi_irq_chip = {
503 .name = "pSeries-PCI-MSI",
504 .irq_shutdown = pseries_msi_shutdown,
505 .irq_mask = pseries_msi_mask,
506 .irq_unmask = pseries_msi_unmask,
507 .irq_eoi = irq_chip_eoi_parent,
508 .irq_write_msi_msg = pseries_msi_write_msg,
509};
510
511
512/*
513 * Set MSI_FLAG_MSIX_CONTIGUOUS as there is no way to express to
514 * firmware to request a discontiguous or non-zero based range of
515 * MSI-X entries. Core code will reject such setup attempts.
516 */
517static struct msi_domain_info pseries_msi_domain_info = {
518 .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
519 MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX |
520 MSI_FLAG_MSIX_CONTIGUOUS),
521 .ops = &pseries_pci_msi_domain_ops,
522 .chip = &pseries_pci_msi_irq_chip,
523};
524
525static void pseries_msi_compose_msg(struct irq_data *data, struct msi_msg *msg)
526{
527 __pci_read_msi_msg(entry: irq_data_get_msi_desc(d: data), msg);
528}
529
530static struct irq_chip pseries_msi_irq_chip = {
531 .name = "pSeries-MSI",
532 .irq_shutdown = pseries_msi_shutdown,
533 .irq_mask = irq_chip_mask_parent,
534 .irq_unmask = irq_chip_unmask_parent,
535 .irq_eoi = irq_chip_eoi_parent,
536 .irq_set_affinity = irq_chip_set_affinity_parent,
537 .irq_compose_msi_msg = pseries_msi_compose_msg,
538};
539
540static int pseries_irq_parent_domain_alloc(struct irq_domain *domain, unsigned int virq,
541 irq_hw_number_t hwirq)
542{
543 struct irq_fwspec parent_fwspec;
544 int ret;
545
546 parent_fwspec.fwnode = domain->parent->fwnode;
547 parent_fwspec.param_count = 2;
548 parent_fwspec.param[0] = hwirq;
549 parent_fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
550
551 ret = irq_domain_alloc_irqs_parent(domain, irq_base: virq, nr_irqs: 1, arg: &parent_fwspec);
552 if (ret)
553 return ret;
554
555 return 0;
556}
557
558static int pseries_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
559 unsigned int nr_irqs, void *arg)
560{
561 struct pci_controller *phb = domain->host_data;
562 msi_alloc_info_t *info = arg;
563 struct msi_desc *desc = info->desc;
564 struct pci_dev *pdev = msi_desc_to_pci_dev(desc);
565 int hwirq;
566 int i, ret;
567
568 hwirq = rtas_query_irq_number(pdn: pci_get_pdn(pdev), offset: desc->msi_index);
569 if (hwirq < 0) {
570 dev_err(&pdev->dev, "Failed to query HW IRQ: %d\n", hwirq);
571 return hwirq;
572 }
573
574 dev_dbg(&pdev->dev, "%s bridge %pOF %d/%x #%d\n", __func__,
575 phb->dn, virq, hwirq, nr_irqs);
576
577 for (i = 0; i < nr_irqs; i++) {
578 ret = pseries_irq_parent_domain_alloc(domain, virq: virq + i, hwirq: hwirq + i);
579 if (ret)
580 goto out;
581
582 irq_domain_set_hwirq_and_chip(domain, virq: virq + i, hwirq: hwirq + i,
583 chip: &pseries_msi_irq_chip, chip_data: domain->host_data);
584 }
585
586 return 0;
587
588out:
589 /* TODO: handle RTAS cleanup in ->msi_finish() ? */
590 irq_domain_free_irqs_parent(domain, irq_base: virq, nr_irqs: i - 1);
591 return ret;
592}
593
594static void pseries_irq_domain_free(struct irq_domain *domain, unsigned int virq,
595 unsigned int nr_irqs)
596{
597 struct irq_data *d = irq_domain_get_irq_data(domain, virq);
598 struct pci_controller *phb = irq_data_get_irq_chip_data(d);
599
600 pr_debug("%s bridge %pOF %d #%d\n", __func__, phb->dn, virq, nr_irqs);
601
602 /* XIVE domain data is cleared through ->msi_free() */
603}
604
605static const struct irq_domain_ops pseries_irq_domain_ops = {
606 .alloc = pseries_irq_domain_alloc,
607 .free = pseries_irq_domain_free,
608};
609
610static int __pseries_msi_allocate_domains(struct pci_controller *phb,
611 unsigned int count)
612{
613 struct irq_domain *parent = irq_get_default_host();
614
615 phb->fwnode = irq_domain_alloc_named_id_fwnode(name: "pSeries-MSI",
616 id: phb->global_number);
617 if (!phb->fwnode)
618 return -ENOMEM;
619
620 phb->dev_domain = irq_domain_create_hierarchy(parent, flags: 0, size: count,
621 fwnode: phb->fwnode,
622 ops: &pseries_irq_domain_ops, host_data: phb);
623 if (!phb->dev_domain) {
624 pr_err("PCI: failed to create IRQ domain bridge %pOF (domain %d)\n",
625 phb->dn, phb->global_number);
626 irq_domain_free_fwnode(fwnode: phb->fwnode);
627 return -ENOMEM;
628 }
629
630 phb->msi_domain = pci_msi_create_irq_domain(fwnode: of_node_to_fwnode(node: phb->dn),
631 info: &pseries_msi_domain_info,
632 parent: phb->dev_domain);
633 if (!phb->msi_domain) {
634 pr_err("PCI: failed to create MSI IRQ domain bridge %pOF (domain %d)\n",
635 phb->dn, phb->global_number);
636 irq_domain_free_fwnode(fwnode: phb->fwnode);
637 irq_domain_remove(host: phb->dev_domain);
638 return -ENOMEM;
639 }
640
641 return 0;
642}
643
644int pseries_msi_allocate_domains(struct pci_controller *phb)
645{
646 int count;
647
648 if (!__find_pe_total_msi(node: phb->dn, total: &count)) {
649 pr_err("PCI: failed to find MSIs for bridge %pOF (domain %d)\n",
650 phb->dn, phb->global_number);
651 return -ENOSPC;
652 }
653
654 return __pseries_msi_allocate_domains(phb, count);
655}
656
657void pseries_msi_free_domains(struct pci_controller *phb)
658{
659 if (phb->msi_domain)
660 irq_domain_remove(host: phb->msi_domain);
661 if (phb->dev_domain)
662 irq_domain_remove(host: phb->dev_domain);
663 if (phb->fwnode)
664 irq_domain_free_fwnode(fwnode: phb->fwnode);
665}
666
667static void rtas_msi_pci_irq_fixup(struct pci_dev *pdev)
668{
669 /* No LSI -> leave MSIs (if any) configured */
670 if (!pdev->irq) {
671 dev_dbg(&pdev->dev, "rtas_msi: no LSI, nothing to do.\n");
672 return;
673 }
674
675 /* No MSI -> MSIs can't have been assigned by fw, leave LSI */
676 if (check_req_msi(pdev, nvec: 1) && check_req_msix(pdev, nvec: 1)) {
677 dev_dbg(&pdev->dev, "rtas_msi: no req#msi/x, nothing to do.\n");
678 return;
679 }
680
681 dev_dbg(&pdev->dev, "rtas_msi: disabling existing MSI.\n");
682 rtas_disable_msi(pdev);
683}
684
685static int rtas_msi_init(void)
686{
687 query_token = rtas_function_token(RTAS_FN_IBM_QUERY_INTERRUPT_SOURCE_NUMBER);
688 change_token = rtas_function_token(RTAS_FN_IBM_CHANGE_MSI);
689
690 if ((query_token == RTAS_UNKNOWN_SERVICE) ||
691 (change_token == RTAS_UNKNOWN_SERVICE)) {
692 pr_debug("rtas_msi: no RTAS tokens, no MSI support.\n");
693 return -1;
694 }
695
696 pr_debug("rtas_msi: Registering RTAS MSI callbacks.\n");
697
698 WARN_ON(ppc_md.pci_irq_fixup);
699 ppc_md.pci_irq_fixup = rtas_msi_pci_irq_fixup;
700
701 return 0;
702}
703machine_arch_initcall(pseries, rtas_msi_init);
704

source code of linux/arch/powerpc/platforms/pseries/msi.c