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1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * PCI Message Signaled Interrupt (MSI)
4 *
5 * Copyright (C) 2003-2004 Intel
6 * Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
7 * Copyright (C) 2016 Christoph Hellwig.
8 */
9
10 #include <linux/err.h>
11 #include <linux/mm.h>
12 #include <linux/irq.h>
13 #include <linux/interrupt.h>
14 #include <linux/export.h>
15 #include <linux/ioport.h>
16 #include <linux/pci.h>
17 #include <linux/proc_fs.h>
18 #include <linux/msi.h>
19 #include <linux/smp.h>
20 #include <linux/errno.h>
21 #include <linux/io.h>
22 #include <linux/acpi_iort.h>
23 #include <linux/slab.h>
24 #include <linux/irqdomain.h>
25 #include <linux/of_irq.h>
26
27 #include "pci.h"
28
29 static int pci_msi_enable = 1;
30 int pci_msi_ignore_mask;
31
32 #define msix_table_size(flags) ((flags & PCI_MSIX_FLAGS_QSIZE) + 1)
33
34 #ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
35 static int pci_msi_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
36 {
37 struct irq_domain *domain;
38
39 domain = dev_get_msi_domain(&dev->dev);
40 if (domain && irq_domain_is_hierarchy(domain))
41 return msi_domain_alloc_irqs(domain, &dev->dev, nvec);
42
43 return arch_setup_msi_irqs(dev, nvec, type);
44 }
45
46 static void pci_msi_teardown_msi_irqs(struct pci_dev *dev)
47 {
48 struct irq_domain *domain;
49
50 domain = dev_get_msi_domain(&dev->dev);
51 if (domain && irq_domain_is_hierarchy(domain))
52 msi_domain_free_irqs(domain, &dev->dev);
53 else
54 arch_teardown_msi_irqs(dev);
55 }
56 #else
57 #define pci_msi_setup_msi_irqs arch_setup_msi_irqs
58 #define pci_msi_teardown_msi_irqs arch_teardown_msi_irqs
59 #endif
60
61 /* Arch hooks */
62
63 int __weak arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
64 {
65 struct msi_controller *chip = dev->bus->msi;
66 int err;
67
68 if (!chip || !chip->setup_irq)
69 return -EINVAL;
70
71 err = chip->setup_irq(chip, dev, desc);
72 if (err < 0)
73 return err;
74
75 irq_set_chip_data(desc->irq, chip);
76
77 return 0;
78 }
79
80 void __weak arch_teardown_msi_irq(unsigned int irq)
81 {
82 struct msi_controller *chip = irq_get_chip_data(irq);
83
84 if (!chip || !chip->teardown_irq)
85 return;
86
87 chip->teardown_irq(chip, irq);
88 }
89
90 int __weak arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
91 {
92 struct msi_controller *chip = dev->bus->msi;
93 struct msi_desc *entry;
94 int ret;
95
96 if (chip && chip->setup_irqs)
97 return chip->setup_irqs(chip, dev, nvec, type);
98 /*
99 * If an architecture wants to support multiple MSI, it needs to
100 * override arch_setup_msi_irqs()
101 */
102 if (type == PCI_CAP_ID_MSI && nvec > 1)
103 return 1;
104
105 for_each_pci_msi_entry(entry, dev) {
106 ret = arch_setup_msi_irq(dev, entry);
107 if (ret < 0)
108 return ret;
109 if (ret > 0)
110 return -ENOSPC;
111 }
112
113 return 0;
114 }
115
116 /*
117 * We have a default implementation available as a separate non-weak
118 * function, as it is used by the Xen x86 PCI code
119 */
120 void default_teardown_msi_irqs(struct pci_dev *dev)
121 {
122 int i;
123 struct msi_desc *entry;
124
125 for_each_pci_msi_entry(entry, dev)
126 if (entry->irq)
127 for (i = 0; i < entry->nvec_used; i++)
128 arch_teardown_msi_irq(entry->irq + i);
129 }
130
131 void __weak arch_teardown_msi_irqs(struct pci_dev *dev)
132 {
133 return default_teardown_msi_irqs(dev);
134 }
135
136 static void default_restore_msi_irq(struct pci_dev *dev, int irq)
137 {
138 struct msi_desc *entry;
139
140 entry = NULL;
141 if (dev->msix_enabled) {
142 for_each_pci_msi_entry(entry, dev) {
143 if (irq == entry->irq)
144 break;
145 }
146 } else if (dev->msi_enabled) {
147 entry = irq_get_msi_desc(irq);
148 }
149
150 if (entry)
151 __pci_write_msi_msg(entry, &entry->msg);
152 }
153
154 void __weak arch_restore_msi_irqs(struct pci_dev *dev)
155 {
156 return default_restore_msi_irqs(dev);
157 }
158
159 static inline __attribute_const__ u32 msi_mask(unsigned x)
160 {
161 /* Don't shift by >= width of type */
162 if (x >= 5)
163 return 0xffffffff;
164 return (1 << (1 << x)) - 1;
165 }
166
167 /*
168 * PCI 2.3 does not specify mask bits for each MSI interrupt. Attempting to
169 * mask all MSI interrupts by clearing the MSI enable bit does not work
170 * reliably as devices without an INTx disable bit will then generate a
171 * level IRQ which will never be cleared.
172 */
173 u32 __pci_msi_desc_mask_irq(struct msi_desc *desc, u32 mask, u32 flag)
174 {
175 u32 mask_bits = desc->masked;
176
177 if (pci_msi_ignore_mask || !desc->msi_attrib.maskbit)
178 return 0;
179
180 mask_bits &= ~mask;
181 mask_bits |= flag;
182 pci_write_config_dword(msi_desc_to_pci_dev(desc), desc->mask_pos,
183 mask_bits);
184
185 return mask_bits;
186 }
187
188 static void msi_mask_irq(struct msi_desc *desc, u32 mask, u32 flag)
189 {
190 desc->masked = __pci_msi_desc_mask_irq(desc, mask, flag);
191 }
192
193 static void __iomem *pci_msix_desc_addr(struct msi_desc *desc)
194 {
195 return desc->mask_base +
196 desc->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE;
197 }
198
199 /*
200 * This internal function does not flush PCI writes to the device.
201 * All users must ensure that they read from the device before either
202 * assuming that the device state is up to date, or returning out of this
203 * file. This saves a few milliseconds when initialising devices with lots
204 * of MSI-X interrupts.
205 */
206 u32 __pci_msix_desc_mask_irq(struct msi_desc *desc, u32 flag)
207 {
208 u32 mask_bits = desc->masked;
209
210 if (pci_msi_ignore_mask)
211 return 0;
212
213 mask_bits &= ~PCI_MSIX_ENTRY_CTRL_MASKBIT;
214 if (flag)
215 mask_bits |= PCI_MSIX_ENTRY_CTRL_MASKBIT;
216 writel(mask_bits, pci_msix_desc_addr(desc) + PCI_MSIX_ENTRY_VECTOR_CTRL);
217
218 return mask_bits;
219 }
220
221 static void msix_mask_irq(struct msi_desc *desc, u32 flag)
222 {
223 desc->masked = __pci_msix_desc_mask_irq(desc, flag);
224 }
225
226 static void msi_set_mask_bit(struct irq_data *data, u32 flag)
227 {
228 struct msi_desc *desc = irq_data_get_msi_desc(data);
229
230 if (desc->msi_attrib.is_msix) {
231 msix_mask_irq(desc, flag);
232 readl(desc->mask_base); /* Flush write to device */
233 } else {
234 unsigned offset = data->irq - desc->irq;
235 msi_mask_irq(desc, 1 << offset, flag << offset);
236 }
237 }
238
239 /**
240 * pci_msi_mask_irq - Generic irq chip callback to mask PCI/MSI interrupts
241 * @data: pointer to irqdata associated to that interrupt
242 */
243 void pci_msi_mask_irq(struct irq_data *data)
244 {
245 msi_set_mask_bit(data, 1);
246 }
247 EXPORT_SYMBOL_GPL(pci_msi_mask_irq);
248
249 /**
250 * pci_msi_unmask_irq - Generic irq chip callback to unmask PCI/MSI interrupts
251 * @data: pointer to irqdata associated to that interrupt
252 */
253 void pci_msi_unmask_irq(struct irq_data *data)
254 {
255 msi_set_mask_bit(data, 0);
256 }
257 EXPORT_SYMBOL_GPL(pci_msi_unmask_irq);
258
259 void default_restore_msi_irqs(struct pci_dev *dev)
260 {
261 struct msi_desc *entry;
262
263 for_each_pci_msi_entry(entry, dev)
264 default_restore_msi_irq(dev, entry->irq);
265 }
266
267 void __pci_read_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
268 {
269 struct pci_dev *dev = msi_desc_to_pci_dev(entry);
270
271 BUG_ON(dev->current_state != PCI_D0);
272
273 if (entry->msi_attrib.is_msix) {
274 void __iomem *base = pci_msix_desc_addr(entry);
275
276 msg->address_lo = readl(base + PCI_MSIX_ENTRY_LOWER_ADDR);
277 msg->address_hi = readl(base + PCI_MSIX_ENTRY_UPPER_ADDR);
278 msg->data = readl(base + PCI_MSIX_ENTRY_DATA);
279 } else {
280 int pos = dev->msi_cap;
281 u16 data;
282
283 pci_read_config_dword(dev, pos + PCI_MSI_ADDRESS_LO,
284 &msg->address_lo);
285 if (entry->msi_attrib.is_64) {
286 pci_read_config_dword(dev, pos + PCI_MSI_ADDRESS_HI,
287 &msg->address_hi);
288 pci_read_config_word(dev, pos + PCI_MSI_DATA_64, &data);
289 } else {
290 msg->address_hi = 0;
291 pci_read_config_word(dev, pos + PCI_MSI_DATA_32, &data);
292 }
293 msg->data = data;
294 }
295 }
296
297 void __pci_write_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
298 {
299 struct pci_dev *dev = msi_desc_to_pci_dev(entry);
300
301 if (dev->current_state != PCI_D0 || pci_dev_is_disconnected(dev)) {
302 /* Don't touch the hardware now */
303 } else if (entry->msi_attrib.is_msix) {
304 void __iomem *base = pci_msix_desc_addr(entry);
305
306 writel(msg->address_lo, base + PCI_MSIX_ENTRY_LOWER_ADDR);
307 writel(msg->address_hi, base + PCI_MSIX_ENTRY_UPPER_ADDR);
308 writel(msg->data, base + PCI_MSIX_ENTRY_DATA);
309 } else {
310 int pos = dev->msi_cap;
311 u16 msgctl;
312
313 pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl);
314 msgctl &= ~PCI_MSI_FLAGS_QSIZE;
315 msgctl |= entry->msi_attrib.multiple << 4;
316 pci_write_config_word(dev, pos + PCI_MSI_FLAGS, msgctl);
317
318 pci_write_config_dword(dev, pos + PCI_MSI_ADDRESS_LO,
319 msg->address_lo);
320 if (entry->msi_attrib.is_64) {
321 pci_write_config_dword(dev, pos + PCI_MSI_ADDRESS_HI,
322 msg->address_hi);
323 pci_write_config_word(dev, pos + PCI_MSI_DATA_64,
324 msg->data);
325 } else {
326 pci_write_config_word(dev, pos + PCI_MSI_DATA_32,
327 msg->data);
328 }
329 }
330 entry->msg = *msg;
331 }
332
333 void pci_write_msi_msg(unsigned int irq, struct msi_msg *msg)
334 {
335 struct msi_desc *entry = irq_get_msi_desc(irq);
336
337 __pci_write_msi_msg(entry, msg);
338 }
339 EXPORT_SYMBOL_GPL(pci_write_msi_msg);
340
341 static void free_msi_irqs(struct pci_dev *dev)
342 {
343 struct list_head *msi_list = dev_to_msi_list(&dev->dev);
344 struct msi_desc *entry, *tmp;
345 struct attribute **msi_attrs;
346 struct device_attribute *dev_attr;
347 int i, count = 0;
348
349 for_each_pci_msi_entry(entry, dev)
350 if (entry->irq)
351 for (i = 0; i < entry->nvec_used; i++)
352 BUG_ON(irq_has_action(entry->irq + i));
353
354 pci_msi_teardown_msi_irqs(dev);
355
356 list_for_each_entry_safe(entry, tmp, msi_list, list) {
357 if (entry->msi_attrib.is_msix) {
358 if (list_is_last(&entry->list, msi_list))
359 iounmap(entry->mask_base);
360 }
361
362 list_del(&entry->list);
363 free_msi_entry(entry);
364 }
365
366 if (dev->msi_irq_groups) {
367 sysfs_remove_groups(&dev->dev.kobj, dev->msi_irq_groups);
368 msi_attrs = dev->msi_irq_groups[0]->attrs;
369 while (msi_attrs[count]) {
370 dev_attr = container_of(msi_attrs[count],
371 struct device_attribute, attr);
372 kfree(dev_attr->attr.name);
373 kfree(dev_attr);
374 ++count;
375 }
376 kfree(msi_attrs);
377 kfree(dev->msi_irq_groups[0]);
378 kfree(dev->msi_irq_groups);
379 dev->msi_irq_groups = NULL;
380 }
381 }
382
383 static void pci_intx_for_msi(struct pci_dev *dev, int enable)
384 {
385 if (!(dev->dev_flags & PCI_DEV_FLAGS_MSI_INTX_DISABLE_BUG))
386 pci_intx(dev, enable);
387 }
388
389 static void __pci_restore_msi_state(struct pci_dev *dev)
390 {
391 u16 control;
392 struct msi_desc *entry;
393
394 if (!dev->msi_enabled)
395 return;
396
397 entry = irq_get_msi_desc(dev->irq);
398
399 pci_intx_for_msi(dev, 0);
400 pci_msi_set_enable(dev, 0);
401 arch_restore_msi_irqs(dev);
402
403 pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
404 msi_mask_irq(entry, msi_mask(entry->msi_attrib.multi_cap),
405 entry->masked);
406 control &= ~PCI_MSI_FLAGS_QSIZE;
407 control |= (entry->msi_attrib.multiple << 4) | PCI_MSI_FLAGS_ENABLE;
408 pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, control);
409 }
410
411 static void __pci_restore_msix_state(struct pci_dev *dev)
412 {
413 struct msi_desc *entry;
414
415 if (!dev->msix_enabled)
416 return;
417 BUG_ON(list_empty(dev_to_msi_list(&dev->dev)));
418
419 /* route the table */
420 pci_intx_for_msi(dev, 0);
421 pci_msix_clear_and_set_ctrl(dev, 0,
422 PCI_MSIX_FLAGS_ENABLE | PCI_MSIX_FLAGS_MASKALL);
423
424 arch_restore_msi_irqs(dev);
425 for_each_pci_msi_entry(entry, dev)
426 msix_mask_irq(entry, entry->masked);
427
428 pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL, 0);
429 }
430
431 void pci_restore_msi_state(struct pci_dev *dev)
432 {
433 __pci_restore_msi_state(dev);
434 __pci_restore_msix_state(dev);
435 }
436 EXPORT_SYMBOL_GPL(pci_restore_msi_state);
437
438 static ssize_t msi_mode_show(struct device *dev, struct device_attribute *attr,
439 char *buf)
440 {
441 struct msi_desc *entry;
442 unsigned long irq;
443 int retval;
444
445 retval = kstrtoul(attr->attr.name, 10, &irq);
446 if (retval)
447 return retval;
448
449 entry = irq_get_msi_desc(irq);
450 if (entry)
451 return sprintf(buf, "%s\n",
452 entry->msi_attrib.is_msix ? "msix" : "msi");
453
454 return -ENODEV;
455 }
456
457 static int populate_msi_sysfs(struct pci_dev *pdev)
458 {
459 struct attribute **msi_attrs;
460 struct attribute *msi_attr;
461 struct device_attribute *msi_dev_attr;
462 struct attribute_group *msi_irq_group;
463 const struct attribute_group **msi_irq_groups;
464 struct msi_desc *entry;
465 int ret = -ENOMEM;
466 int num_msi = 0;
467 int count = 0;
468 int i;
469
470 /* Determine how many msi entries we have */
471 for_each_pci_msi_entry(entry, pdev)
472 num_msi += entry->nvec_used;
473 if (!num_msi)
474 return 0;
475
476 /* Dynamically create the MSI attributes for the PCI device */
477 msi_attrs = kcalloc(num_msi + 1, sizeof(void *), GFP_KERNEL);
478 if (!msi_attrs)
479 return -ENOMEM;
480 for_each_pci_msi_entry(entry, pdev) {
481 for (i = 0; i < entry->nvec_used; i++) {
482 msi_dev_attr = kzalloc(sizeof(*msi_dev_attr), GFP_KERNEL);
483 if (!msi_dev_attr)
484 goto error_attrs;
485 msi_attrs[count] = &msi_dev_attr->attr;
486
487 sysfs_attr_init(&msi_dev_attr->attr);
488 msi_dev_attr->attr.name = kasprintf(GFP_KERNEL, "%d",
489 entry->irq + i);
490 if (!msi_dev_attr->attr.name)
491 goto error_attrs;
492 msi_dev_attr->attr.mode = S_IRUGO;
493 msi_dev_attr->show = msi_mode_show;
494 ++count;
495 }
496 }
497
498 msi_irq_group = kzalloc(sizeof(*msi_irq_group), GFP_KERNEL);
499 if (!msi_irq_group)
500 goto error_attrs;
501 msi_irq_group->name = "msi_irqs";
502 msi_irq_group->attrs = msi_attrs;
503
504 msi_irq_groups = kcalloc(2, sizeof(void *), GFP_KERNEL);
505 if (!msi_irq_groups)
506 goto error_irq_group;
507 msi_irq_groups[0] = msi_irq_group;
508
509 ret = sysfs_create_groups(&pdev->dev.kobj, msi_irq_groups);
510 if (ret)
511 goto error_irq_groups;
512 pdev->msi_irq_groups = msi_irq_groups;
513
514 return 0;
515
516 error_irq_groups:
517 kfree(msi_irq_groups);
518 error_irq_group:
519 kfree(msi_irq_group);
520 error_attrs:
521 count = 0;
522 msi_attr = msi_attrs[count];
523 while (msi_attr) {
524 msi_dev_attr = container_of(msi_attr, struct device_attribute, attr);
525 kfree(msi_attr->name);
526 kfree(msi_dev_attr);
527 ++count;
528 msi_attr = msi_attrs[count];
529 }
530 kfree(msi_attrs);
531 return ret;
532 }
533
534 static struct msi_desc *
535 msi_setup_entry(struct pci_dev *dev, int nvec, struct irq_affinity *affd)
536 {
537 struct irq_affinity_desc *masks = NULL;
538 struct msi_desc *entry;
539 u16 control;
540
541 if (affd)
542 masks = irq_create_affinity_masks(nvec, affd);
543
544 /* MSI Entry Initialization */
545 entry = alloc_msi_entry(&dev->dev, nvec, masks);
546 if (!entry)
547 goto out;
548
549 pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
550
551 entry->msi_attrib.is_msix = 0;
552 entry->msi_attrib.is_64 = !!(control & PCI_MSI_FLAGS_64BIT);
553 entry->msi_attrib.entry_nr = 0;
554 entry->msi_attrib.maskbit = !!(control & PCI_MSI_FLAGS_MASKBIT);
555 entry->msi_attrib.default_irq = dev->irq; /* Save IOAPIC IRQ */
556 entry->msi_attrib.multi_cap = (control & PCI_MSI_FLAGS_QMASK) >> 1;
557 entry->msi_attrib.multiple = ilog2(__roundup_pow_of_two(nvec));
558
559 if (control & PCI_MSI_FLAGS_64BIT)
560 entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_64;
561 else
562 entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_32;
563
564 /* Save the initial mask status */
565 if (entry->msi_attrib.maskbit)
566 pci_read_config_dword(dev, entry->mask_pos, &entry->masked);
567
568 out:
569 kfree(masks);
570 return entry;
571 }
572
573 static int msi_verify_entries(struct pci_dev *dev)
574 {
575 struct msi_desc *entry;
576
577 for_each_pci_msi_entry(entry, dev) {
578 if (!dev->no_64bit_msi || !entry->msg.address_hi)
579 continue;
580 pci_err(dev, "Device has broken 64-bit MSI but arch"
581 " tried to assign one above 4G\n");
582 return -EIO;
583 }
584 return 0;
585 }
586
587 /**
588 * msi_capability_init - configure device's MSI capability structure
589 * @dev: pointer to the pci_dev data structure of MSI device function
590 * @nvec: number of interrupts to allocate
591 * @affd: description of automatic irq affinity assignments (may be %NULL)
592 *
593 * Setup the MSI capability structure of the device with the requested
594 * number of interrupts. A return value of zero indicates the successful
595 * setup of an entry with the new MSI irq. A negative return value indicates
596 * an error, and a positive return value indicates the number of interrupts
597 * which could have been allocated.
598 */
599 static int msi_capability_init(struct pci_dev *dev, int nvec,
600 struct irq_affinity *affd)
601 {
602 struct msi_desc *entry;
603 int ret;
604 unsigned mask;
605
606 pci_msi_set_enable(dev, 0); /* Disable MSI during set up */
607
608 entry = msi_setup_entry(dev, nvec, affd);
609 if (!entry)
610 return -ENOMEM;
611
612 /* All MSIs are unmasked by default, Mask them all */
613 mask = msi_mask(entry->msi_attrib.multi_cap);
614 msi_mask_irq(entry, mask, mask);
615
616 list_add_tail(&entry->list, dev_to_msi_list(&dev->dev));
617
618 /* Configure MSI capability structure */
619 ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSI);
620 if (ret) {
621 msi_mask_irq(entry, mask, ~mask);
622 free_msi_irqs(dev);
623 return ret;
624 }
625
626 ret = msi_verify_entries(dev);
627 if (ret) {
628 msi_mask_irq(entry, mask, ~mask);
629 free_msi_irqs(dev);
630 return ret;
631 }
632
633 ret = populate_msi_sysfs(dev);
634 if (ret) {
635 msi_mask_irq(entry, mask, ~mask);
636 free_msi_irqs(dev);
637 return ret;
638 }
639
640 /* Set MSI enabled bits */
641 pci_intx_for_msi(dev, 0);
642 pci_msi_set_enable(dev, 1);
643 dev->msi_enabled = 1;
644
645 pcibios_free_irq(dev);
646 dev->irq = entry->irq;
647 return 0;
648 }
649
650 static void __iomem *msix_map_region(struct pci_dev *dev, unsigned nr_entries)
651 {
652 resource_size_t phys_addr;
653 u32 table_offset;
654 unsigned long flags;
655 u8 bir;
656
657 pci_read_config_dword(dev, dev->msix_cap + PCI_MSIX_TABLE,
658 &table_offset);
659 bir = (u8)(table_offset & PCI_MSIX_TABLE_BIR);
660 flags = pci_resource_flags(dev, bir);
661 if (!flags || (flags & IORESOURCE_UNSET))
662 return NULL;
663
664 table_offset &= PCI_MSIX_TABLE_OFFSET;
665 phys_addr = pci_resource_start(dev, bir) + table_offset;
666
667 return ioremap_nocache(phys_addr, nr_entries * PCI_MSIX_ENTRY_SIZE);
668 }
669
670 static int msix_setup_entries(struct pci_dev *dev, void __iomem *base,
671 struct msix_entry *entries, int nvec,
672 struct irq_affinity *affd)
673 {
674 struct irq_affinity_desc *curmsk, *masks = NULL;
675 struct msi_desc *entry;
676 int ret, i;
677
678 if (affd)
679 masks = irq_create_affinity_masks(nvec, affd);
680
681 for (i = 0, curmsk = masks; i < nvec; i++) {
682 entry = alloc_msi_entry(&dev->dev, 1, curmsk);
683 if (!entry) {
684 if (!i)
685 iounmap(base);
686 else
687 free_msi_irqs(dev);
688 /* No enough memory. Don't try again */
689 ret = -ENOMEM;
690 goto out;
691 }
692
693 entry->msi_attrib.is_msix = 1;
694 entry->msi_attrib.is_64 = 1;
695 if (entries)
696 entry->msi_attrib.entry_nr = entries[i].entry;
697 else
698 entry->msi_attrib.entry_nr = i;
699 entry->msi_attrib.default_irq = dev->irq;
700 entry->mask_base = base;
701
702 list_add_tail(&entry->list, dev_to_msi_list(&dev->dev));
703 if (masks)
704 curmsk++;
705 }
706 ret = 0;
707 out:
708 kfree(masks);
709 return ret;
710 }
711
712 static void msix_program_entries(struct pci_dev *dev,
713 struct msix_entry *entries)
714 {
715 struct msi_desc *entry;
716 int i = 0;
717
718 for_each_pci_msi_entry(entry, dev) {
719 if (entries)
720 entries[i++].vector = entry->irq;
721 entry->masked = readl(pci_msix_desc_addr(entry) +
722 PCI_MSIX_ENTRY_VECTOR_CTRL);
723 msix_mask_irq(entry, 1);
724 }
725 }
726
727 /**
728 * msix_capability_init - configure device's MSI-X capability
729 * @dev: pointer to the pci_dev data structure of MSI-X device function
730 * @entries: pointer to an array of struct msix_entry entries
731 * @nvec: number of @entries
732 * @affd: Optional pointer to enable automatic affinity assignement
733 *
734 * Setup the MSI-X capability structure of device function with a
735 * single MSI-X irq. A return of zero indicates the successful setup of
736 * requested MSI-X entries with allocated irqs or non-zero for otherwise.
737 **/
738 static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries,
739 int nvec, struct irq_affinity *affd)
740 {
741 int ret;
742 u16 control;
743 void __iomem *base;
744
745 /* Ensure MSI-X is disabled while it is set up */
746 pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0);
747
748 pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &control);
749 /* Request & Map MSI-X table region */
750 base = msix_map_region(dev, msix_table_size(control));
751 if (!base)
752 return -ENOMEM;
753
754 ret = msix_setup_entries(dev, base, entries, nvec, affd);
755 if (ret)
756 return ret;
757
758 ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSIX);
759 if (ret)
760 goto out_avail;
761
762 /* Check if all MSI entries honor device restrictions */
763 ret = msi_verify_entries(dev);
764 if (ret)
765 goto out_free;
766
767 /*
768 * Some devices require MSI-X to be enabled before we can touch the
769 * MSI-X registers. We need to mask all the vectors to prevent
770 * interrupts coming in before they're fully set up.
771 */
772 pci_msix_clear_and_set_ctrl(dev, 0,
773 PCI_MSIX_FLAGS_MASKALL | PCI_MSIX_FLAGS_ENABLE);
774
775 msix_program_entries(dev, entries);
776
777 ret = populate_msi_sysfs(dev);
778 if (ret)
779 goto out_free;
780
781 /* Set MSI-X enabled bits and unmask the function */
782 pci_intx_for_msi(dev, 0);
783 dev->msix_enabled = 1;
784 pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL, 0);
785
786 pcibios_free_irq(dev);
787 return 0;
788
789 out_avail:
790 if (ret < 0) {
791 /*
792 * If we had some success, report the number of irqs
793 * we succeeded in setting up.
794 */
795 struct msi_desc *entry;
796 int avail = 0;
797
798 for_each_pci_msi_entry(entry, dev) {
799 if (entry->irq != 0)
800 avail++;
801 }
802 if (avail != 0)
803 ret = avail;
804 }
805
806 out_free:
807 free_msi_irqs(dev);
808
809 return ret;
810 }
811
812 /**
813 * pci_msi_supported - check whether MSI may be enabled on a device
814 * @dev: pointer to the pci_dev data structure of MSI device function
815 * @nvec: how many MSIs have been requested ?
816 *
817 * Look at global flags, the device itself, and its parent buses
818 * to determine if MSI/-X are supported for the device. If MSI/-X is
819 * supported return 1, else return 0.
820 **/
821 static int pci_msi_supported(struct pci_dev *dev, int nvec)
822 {
823 struct pci_bus *bus;
824
825 /* MSI must be globally enabled and supported by the device */
826 if (!pci_msi_enable)
827 return 0;
828
829 if (!dev || dev->no_msi || dev->current_state != PCI_D0)
830 return 0;
831
832 /*
833 * You can't ask to have 0 or less MSIs configured.
834 * a) it's stupid ..
835 * b) the list manipulation code assumes nvec >= 1.
836 */
837 if (nvec < 1)
838 return 0;
839
840 /*
841 * Any bridge which does NOT route MSI transactions from its
842 * secondary bus to its primary bus must set NO_MSI flag on
843 * the secondary pci_bus.
844 * We expect only arch-specific PCI host bus controller driver
845 * or quirks for specific PCI bridges to be setting NO_MSI.
846 */
847 for (bus = dev->bus; bus; bus = bus->parent)
848 if (bus->bus_flags & PCI_BUS_FLAGS_NO_MSI)
849 return 0;
850
851 return 1;
852 }
853
854 /**
855 * pci_msi_vec_count - Return the number of MSI vectors a device can send
856 * @dev: device to report about
857 *
858 * This function returns the number of MSI vectors a device requested via
859 * Multiple Message Capable register. It returns a negative errno if the
860 * device is not capable sending MSI interrupts. Otherwise, the call succeeds
861 * and returns a power of two, up to a maximum of 2^5 (32), according to the
862 * MSI specification.
863 **/
864 int pci_msi_vec_count(struct pci_dev *dev)
865 {
866 int ret;
867 u16 msgctl;
868
869 if (!dev->msi_cap)
870 return -EINVAL;
871
872 pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &msgctl);
873 ret = 1 << ((msgctl & PCI_MSI_FLAGS_QMASK) >> 1);
874
875 return ret;
876 }
877 EXPORT_SYMBOL(pci_msi_vec_count);
878
879 static void pci_msi_shutdown(struct pci_dev *dev)
880 {
881 struct msi_desc *desc;
882 u32 mask;
883
884 if (!pci_msi_enable || !dev || !dev->msi_enabled)
885 return;
886
887 BUG_ON(list_empty(dev_to_msi_list(&dev->dev)));
888 desc = first_pci_msi_entry(dev);
889
890 pci_msi_set_enable(dev, 0);
891 pci_intx_for_msi(dev, 1);
892 dev->msi_enabled = 0;
893
894 /* Return the device with MSI unmasked as initial states */
895 mask = msi_mask(desc->msi_attrib.multi_cap);
896 /* Keep cached state to be restored */
897 __pci_msi_desc_mask_irq(desc, mask, ~mask);
898
899 /* Restore dev->irq to its default pin-assertion irq */
900 dev->irq = desc->msi_attrib.default_irq;
901 pcibios_alloc_irq(dev);
902 }
903
904 void pci_disable_msi(struct pci_dev *dev)
905 {
906 if (!pci_msi_enable || !dev || !dev->msi_enabled)
907 return;
908
909 pci_msi_shutdown(dev);
910 free_msi_irqs(dev);
911 }
912 EXPORT_SYMBOL(pci_disable_msi);
913
914 /**
915 * pci_msix_vec_count - return the number of device's MSI-X table entries
916 * @dev: pointer to the pci_dev data structure of MSI-X device function
917 * This function returns the number of device's MSI-X table entries and
918 * therefore the number of MSI-X vectors device is capable of sending.
919 * It returns a negative errno if the device is not capable of sending MSI-X
920 * interrupts.
921 **/
922 int pci_msix_vec_count(struct pci_dev *dev)
923 {
924 u16 control;
925
926 if (!dev->msix_cap)
927 return -EINVAL;
928
929 pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &control);
930 return msix_table_size(control);
931 }
932 EXPORT_SYMBOL(pci_msix_vec_count);
933
934 static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries,
935 int nvec, struct irq_affinity *affd)
936 {
937 int nr_entries;
938 int i, j;
939
940 if (!pci_msi_supported(dev, nvec))
941 return -EINVAL;
942
943 nr_entries = pci_msix_vec_count(dev);
944 if (nr_entries < 0)
945 return nr_entries;
946 if (nvec > nr_entries)
947 return nr_entries;
948
949 if (entries) {
950 /* Check for any invalid entries */
951 for (i = 0; i < nvec; i++) {
952 if (entries[i].entry >= nr_entries)
953 return -EINVAL; /* invalid entry */
954 for (j = i + 1; j < nvec; j++) {
955 if (entries[i].entry == entries[j].entry)
956 return -EINVAL; /* duplicate entry */
957 }
958 }
959 }
960
961 /* Check whether driver already requested for MSI irq */
962 if (dev->msi_enabled) {
963 pci_info(dev, "can't enable MSI-X (MSI IRQ already assigned)\n");
964 return -EINVAL;
965 }
966 return msix_capability_init(dev, entries, nvec, affd);
967 }
968
969 static void pci_msix_shutdown(struct pci_dev *dev)
970 {
971 struct msi_desc *entry;
972
973 if (!pci_msi_enable || !dev || !dev->msix_enabled)
974 return;
975
976 if (pci_dev_is_disconnected(dev)) {
977 dev->msix_enabled = 0;
978 return;
979 }
980
981 /* Return the device with MSI-X masked as initial states */
982 for_each_pci_msi_entry(entry, dev) {
983 /* Keep cached states to be restored */
984 __pci_msix_desc_mask_irq(entry, 1);
985 }
986
987 pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0);
988 pci_intx_for_msi(dev, 1);
989 dev->msix_enabled = 0;
990 pcibios_alloc_irq(dev);
991 }
992
993 void pci_disable_msix(struct pci_dev *dev)
994 {
995 if (!pci_msi_enable || !dev || !dev->msix_enabled)
996 return;
997
998 pci_msix_shutdown(dev);
999 free_msi_irqs(dev);
1000 }
1001 EXPORT_SYMBOL(pci_disable_msix);
1002
1003 void pci_no_msi(void)
1004 {
1005 pci_msi_enable = 0;
1006 }
1007
1008 /**
1009 * pci_msi_enabled - is MSI enabled?
1010 *
1011 * Returns true if MSI has not been disabled by the command-line option
1012 * pci=nomsi.
1013 **/
1014 int pci_msi_enabled(void)
1015 {
1016 return pci_msi_enable;
1017 }
1018 EXPORT_SYMBOL(pci_msi_enabled);
1019
1020 static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
1021 struct irq_affinity *affd)
1022 {
1023 int nvec;
1024 int rc;
1025
1026 if (!pci_msi_supported(dev, minvec))
1027 return -EINVAL;
1028
1029 /* Check whether driver already requested MSI-X irqs */
1030 if (dev->msix_enabled) {
1031 pci_info(dev, "can't enable MSI (MSI-X already enabled)\n");
1032 return -EINVAL;
1033 }
1034
1035 if (maxvec < minvec)
1036 return -ERANGE;
1037
1038 if (WARN_ON_ONCE(dev->msi_enabled))
1039 return -EINVAL;
1040
1041 nvec = pci_msi_vec_count(dev);
1042 if (nvec < 0)
1043 return nvec;
1044 if (nvec < minvec)
1045 return -ENOSPC;
1046
1047 if (nvec > maxvec)
1048 nvec = maxvec;
1049
1050 for (;;) {
1051 if (affd) {
1052 nvec = irq_calc_affinity_vectors(minvec, nvec, affd);
1053 if (nvec < minvec)
1054 return -ENOSPC;
1055 }
1056
1057 rc = msi_capability_init(dev, nvec, affd);
1058 if (rc == 0)
1059 return nvec;
1060
1061 if (rc < 0)
1062 return rc;
1063 if (rc < minvec)
1064 return -ENOSPC;
1065
1066 nvec = rc;
1067 }
1068 }
1069
1070 /* deprecated, don't use */
1071 int pci_enable_msi(struct pci_dev *dev)
1072 {
1073 int rc = __pci_enable_msi_range(dev, 1, 1, NULL);
1074 if (rc < 0)
1075 return rc;
1076 return 0;
1077 }
1078 EXPORT_SYMBOL(pci_enable_msi);
1079
1080 static int __pci_enable_msix_range(struct pci_dev *dev,
1081 struct msix_entry *entries, int minvec,
1082 int maxvec, struct irq_affinity *affd)
1083 {
1084 int rc, nvec = maxvec;
1085
1086 if (maxvec < minvec)
1087 return -ERANGE;
1088
1089 if (WARN_ON_ONCE(dev->msix_enabled))
1090 return -EINVAL;
1091
1092 for (;;) {
1093 if (affd) {
1094 nvec = irq_calc_affinity_vectors(minvec, nvec, affd);
1095 if (nvec < minvec)
1096 return -ENOSPC;
1097 }
1098
1099 rc = __pci_enable_msix(dev, entries, nvec, affd);
1100 if (rc == 0)
1101 return nvec;
1102
1103 if (rc < 0)
1104 return rc;
1105 if (rc < minvec)
1106 return -ENOSPC;
1107
1108 nvec = rc;
1109 }
1110 }
1111
1112 /**
1113 * pci_enable_msix_range - configure device's MSI-X capability structure
1114 * @dev: pointer to the pci_dev data structure of MSI-X device function
1115 * @entries: pointer to an array of MSI-X entries
1116 * @minvec: minimum number of MSI-X irqs requested
1117 * @maxvec: maximum number of MSI-X irqs requested
1118 *
1119 * Setup the MSI-X capability structure of device function with a maximum
1120 * possible number of interrupts in the range between @minvec and @maxvec
1121 * upon its software driver call to request for MSI-X mode enabled on its
1122 * hardware device function. It returns a negative errno if an error occurs.
1123 * If it succeeds, it returns the actual number of interrupts allocated and
1124 * indicates the successful configuration of MSI-X capability structure
1125 * with new allocated MSI-X interrupts.
1126 **/
1127 int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries,
1128 int minvec, int maxvec)
1129 {
1130 return __pci_enable_msix_range(dev, entries, minvec, maxvec, NULL);
1131 }
1132 EXPORT_SYMBOL(pci_enable_msix_range);
1133
1134 /**
1135 * pci_alloc_irq_vectors_affinity - allocate multiple IRQs for a device
1136 * @dev: PCI device to operate on
1137 * @min_vecs: minimum number of vectors required (must be >= 1)
1138 * @max_vecs: maximum (desired) number of vectors
1139 * @flags: flags or quirks for the allocation
1140 * @affd: optional description of the affinity requirements
1141 *
1142 * Allocate up to @max_vecs interrupt vectors for @dev, using MSI-X or MSI
1143 * vectors if available, and fall back to a single legacy vector
1144 * if neither is available. Return the number of vectors allocated,
1145 * (which might be smaller than @max_vecs) if successful, or a negative
1146 * error code on error. If less than @min_vecs interrupt vectors are
1147 * available for @dev the function will fail with -ENOSPC.
1148 *
1149 * To get the Linux IRQ number used for a vector that can be passed to
1150 * request_irq() use the pci_irq_vector() helper.
1151 */
1152 int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
1153 unsigned int max_vecs, unsigned int flags,
1154 struct irq_affinity *affd)
1155 {
1156 struct irq_affinity msi_default_affd = {0};
1157 int msix_vecs = -ENOSPC;
1158 int msi_vecs = -ENOSPC;
1159
1160 if (flags & PCI_IRQ_AFFINITY) {
1161 if (!affd)
1162 affd = &msi_default_affd;
1163 } else {
1164 if (WARN_ON(affd))
1165 affd = NULL;
1166 }
1167
1168 if (flags & PCI_IRQ_MSIX) {
1169 msix_vecs = __pci_enable_msix_range(dev, NULL, min_vecs,
1170 max_vecs, affd);
1171 if (msix_vecs > 0)
1172 return msix_vecs;
1173 }
1174
1175 if (flags & PCI_IRQ_MSI) {
1176 msi_vecs = __pci_enable_msi_range(dev, min_vecs, max_vecs,
1177 affd);
1178 if (msi_vecs > 0)
1179 return msi_vecs;
1180 }
1181
1182 /* use legacy irq if allowed */
1183 if (flags & PCI_IRQ_LEGACY) {
1184 if (min_vecs == 1 && dev->irq) {
1185 /*
1186 * Invoke the affinity spreading logic to ensure that
1187 * the device driver can adjust queue configuration
1188 * for the single interrupt case.
1189 */
1190 if (affd)
1191 irq_create_affinity_masks(1, affd);
1192 pci_intx(dev, 1);
1193 return 1;
1194 }
1195 }
1196
1197 if (msix_vecs == -ENOSPC)
1198 return -ENOSPC;
1199 return msi_vecs;
1200 }
1201 EXPORT_SYMBOL(pci_alloc_irq_vectors_affinity);
1202
1203 /**
1204 * pci_free_irq_vectors - free previously allocated IRQs for a device
1205 * @dev: PCI device to operate on
1206 *
1207 * Undoes the allocations and enabling in pci_alloc_irq_vectors().
1208 */
1209 void pci_free_irq_vectors(struct pci_dev *dev)
1210 {
1211 pci_disable_msix(dev);
1212 pci_disable_msi(dev);
1213 }
1214 EXPORT_SYMBOL(pci_free_irq_vectors);
1215
1216 /**
1217 * pci_irq_vector - return Linux IRQ number of a device vector
1218 * @dev: PCI device to operate on
1219 * @nr: device-relative interrupt vector index (0-based).
1220 */
1221 int pci_irq_vector(struct pci_dev *dev, unsigned int nr)
1222 {
1223 if (dev->msix_enabled) {
1224 struct msi_desc *entry;
1225 int i = 0;
1226
1227 for_each_pci_msi_entry(entry, dev) {
1228 if (i == nr)
1229 return entry->irq;
1230 i++;
1231 }
1232 WARN_ON_ONCE(1);
1233 return -EINVAL;
1234 }
1235
1236 if (dev->msi_enabled) {
1237 struct msi_desc *entry = first_pci_msi_entry(dev);
1238
1239 if (WARN_ON_ONCE(nr >= entry->nvec_used))
1240 return -EINVAL;
1241 } else {
1242 if (WARN_ON_ONCE(nr > 0))
1243 return -EINVAL;
1244 }
1245
1246 return dev->irq + nr;
1247 }
1248 EXPORT_SYMBOL(pci_irq_vector);
1249
1250 /**
1251 * pci_irq_get_affinity - return the affinity of a particular msi vector
1252 * @dev: PCI device to operate on
1253 * @nr: device-relative interrupt vector index (0-based).
1254 */
1255 const struct cpumask *pci_irq_get_affinity(struct pci_dev *dev, int nr)
1256 {
1257 if (dev->msix_enabled) {
1258 struct msi_desc *entry;
1259 int i = 0;
1260
1261 for_each_pci_msi_entry(entry, dev) {
1262 if (i == nr)
1263 return &entry->affinity->mask;
1264 i++;
1265 }
1266 WARN_ON_ONCE(1);
1267 return NULL;
1268 } else if (dev->msi_enabled) {
1269 struct msi_desc *entry = first_pci_msi_entry(dev);
1270
1271 if (WARN_ON_ONCE(!entry || !entry->affinity ||
1272 nr >= entry->nvec_used))
1273 return NULL;
1274
1275 return &entry->affinity[nr].mask;
1276 } else {
1277 return cpu_possible_mask;
1278 }
1279 }
1280 EXPORT_SYMBOL(pci_irq_get_affinity);
1281
1282 /**
1283 * pci_irq_get_node - return the numa node of a particular msi vector
1284 * @pdev: PCI device to operate on
1285 * @vec: device-relative interrupt vector index (0-based).
1286 */
1287 int pci_irq_get_node(struct pci_dev *pdev, int vec)
1288 {
1289 const struct cpumask *mask;
1290
1291 mask = pci_irq_get_affinity(pdev, vec);
1292 if (mask)
1293 return local_memory_node(cpu_to_node(cpumask_first(mask)));
1294 return dev_to_node(&pdev->dev);
1295 }
1296 EXPORT_SYMBOL(pci_irq_get_node);
1297
1298 struct pci_dev *msi_desc_to_pci_dev(struct msi_desc *desc)
1299 {
1300 return to_pci_dev(desc->dev);
1301 }
1302 EXPORT_SYMBOL(msi_desc_to_pci_dev);
1303
1304 void *msi_desc_to_pci_sysdata(struct msi_desc *desc)
1305 {
1306 struct pci_dev *dev = msi_desc_to_pci_dev(desc);
1307
1308 return dev->bus->sysdata;
1309 }
1310 EXPORT_SYMBOL_GPL(msi_desc_to_pci_sysdata);
1311
1312 #ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
1313 /**
1314 * pci_msi_domain_write_msg - Helper to write MSI message to PCI config space
1315 * @irq_data: Pointer to interrupt data of the MSI interrupt
1316 * @msg: Pointer to the message
1317 */
1318 void pci_msi_domain_write_msg(struct irq_data *irq_data, struct msi_msg *msg)
1319 {
1320 struct msi_desc *desc = irq_data_get_msi_desc(irq_data);
1321
1322 /*
1323 * For MSI-X desc->irq is always equal to irq_data->irq. For
1324 * MSI only the first interrupt of MULTI MSI passes the test.
1325 */
1326 if (desc->irq == irq_data->irq)
1327 __pci_write_msi_msg(desc, msg);
1328 }
1329
1330 /**
1331 * pci_msi_domain_calc_hwirq - Generate a unique ID for an MSI source
1332 * @dev: Pointer to the PCI device
1333 * @desc: Pointer to the msi descriptor
1334 *
1335 * The ID number is only used within the irqdomain.
1336 */
1337 irq_hw_number_t pci_msi_domain_calc_hwirq(struct pci_dev *dev,
1338 struct msi_desc *desc)
1339 {
1340 return (irq_hw_number_t)desc->msi_attrib.entry_nr |
1341 PCI_DEVID(dev->bus->number, dev->devfn) << 11 |
1342 (pci_domain_nr(dev->bus) & 0xFFFFFFFF) << 27;
1343 }
1344
1345 static inline bool pci_msi_desc_is_multi_msi(struct msi_desc *desc)
1346 {
1347 return !desc->msi_attrib.is_msix && desc->nvec_used > 1;
1348 }
1349
1350 /**
1351 * pci_msi_domain_check_cap - Verify that @domain supports the capabilities for @dev
1352 * @domain: The interrupt domain to check
1353 * @info: The domain info for verification
1354 * @dev: The device to check
1355 *
1356 * Returns:
1357 * 0 if the functionality is supported
1358 * 1 if Multi MSI is requested, but the domain does not support it
1359 * -ENOTSUPP otherwise
1360 */
1361 int pci_msi_domain_check_cap(struct irq_domain *domain,
1362 struct msi_domain_info *info, struct device *dev)
1363 {
1364 struct msi_desc *desc = first_pci_msi_entry(to_pci_dev(dev));
1365
1366 /* Special handling to support __pci_enable_msi_range() */
1367 if (pci_msi_desc_is_multi_msi(desc) &&
1368 !(info->flags & MSI_FLAG_MULTI_PCI_MSI))
1369 return 1;
1370 else if (desc->msi_attrib.is_msix && !(info->flags & MSI_FLAG_PCI_MSIX))
1371 return -ENOTSUPP;
1372
1373 return 0;
1374 }
1375
1376 static int pci_msi_domain_handle_error(struct irq_domain *domain,
1377 struct msi_desc *desc, int error)
1378 {
1379 /* Special handling to support __pci_enable_msi_range() */
1380 if (pci_msi_desc_is_multi_msi(desc) && error == -ENOSPC)
1381 return 1;
1382
1383 return error;
1384 }
1385
1386 #ifdef GENERIC_MSI_DOMAIN_OPS
1387 static void pci_msi_domain_set_desc(msi_alloc_info_t *arg,
1388 struct msi_desc *desc)
1389 {
1390 arg->desc = desc;
1391 arg->hwirq = pci_msi_domain_calc_hwirq(msi_desc_to_pci_dev(desc),
1392 desc);
1393 }
1394 #else
1395 #define pci_msi_domain_set_desc NULL
1396 #endif
1397
1398 static struct msi_domain_ops pci_msi_domain_ops_default = {
1399 .set_desc = pci_msi_domain_set_desc,
1400 .msi_check = pci_msi_domain_check_cap,
1401 .handle_error = pci_msi_domain_handle_error,
1402 };
1403
1404 static void pci_msi_domain_update_dom_ops(struct msi_domain_info *info)
1405 {
1406 struct msi_domain_ops *ops = info->ops;
1407
1408 if (ops == NULL) {
1409 info->ops = &pci_msi_domain_ops_default;
1410 } else {
1411 if (ops->set_desc == NULL)
1412 ops->set_desc = pci_msi_domain_set_desc;
1413 if (ops->msi_check == NULL)
1414 ops->msi_check = pci_msi_domain_check_cap;
1415 if (ops->handle_error == NULL)
1416 ops->handle_error = pci_msi_domain_handle_error;
1417 }
1418 }
1419
1420 static void pci_msi_domain_update_chip_ops(struct msi_domain_info *info)
1421 {
1422 struct irq_chip *chip = info->chip;
1423
1424 BUG_ON(!chip);
1425 if (!chip->irq_write_msi_msg)
1426 chip->irq_write_msi_msg = pci_msi_domain_write_msg;
1427 if (!chip->irq_mask)
1428 chip->irq_mask = pci_msi_mask_irq;
1429 if (!chip->irq_unmask)
1430 chip->irq_unmask = pci_msi_unmask_irq;
1431 }
1432
1433 /**
1434 * pci_msi_create_irq_domain - Create a MSI interrupt domain
1435 * @fwnode: Optional fwnode of the interrupt controller
1436 * @info: MSI domain info
1437 * @parent: Parent irq domain
1438 *
1439 * Updates the domain and chip ops and creates a MSI interrupt domain.
1440 *
1441 * Returns:
1442 * A domain pointer or NULL in case of failure.
1443 */
1444 struct irq_domain *pci_msi_create_irq_domain(struct fwnode_handle *fwnode,
1445 struct msi_domain_info *info,
1446 struct irq_domain *parent)
1447 {
1448 struct irq_domain *domain;
1449
1450 if (WARN_ON(info->flags & MSI_FLAG_LEVEL_CAPABLE))
1451 info->flags &= ~MSI_FLAG_LEVEL_CAPABLE;
1452
1453 if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
1454 pci_msi_domain_update_dom_ops(info);
1455 if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
1456 pci_msi_domain_update_chip_ops(info);
1457
1458 info->flags |= MSI_FLAG_ACTIVATE_EARLY;
1459 if (IS_ENABLED(CONFIG_GENERIC_IRQ_RESERVATION_MODE))
1460 info->flags |= MSI_FLAG_MUST_REACTIVATE;
1461
1462 /* PCI-MSI is oneshot-safe */
1463 info->chip->flags |= IRQCHIP_ONESHOT_SAFE;
1464
1465 domain = msi_create_irq_domain(fwnode, info, parent);
1466 if (!domain)
1467 return NULL;
1468
1469 irq_domain_update_bus_token(domain, DOMAIN_BUS_PCI_MSI);
1470 return domain;
1471 }
1472 EXPORT_SYMBOL_GPL(pci_msi_create_irq_domain);
1473
1474 /*
1475 * Users of the generic MSI infrastructure expect a device to have a single ID,
1476 * so with DMA aliases we have to pick the least-worst compromise. Devices with
1477 * DMA phantom functions tend to still emit MSIs from the real function number,
1478 * so we ignore those and only consider topological aliases where either the
1479 * alias device or RID appears on a different bus number. We also make the
1480 * reasonable assumption that bridges are walked in an upstream direction (so
1481 * the last one seen wins), and the much braver assumption that the most likely
1482 * case is that of PCI->PCIe so we should always use the alias RID. This echoes
1483 * the logic from intel_irq_remapping's set_msi_sid(), which presumably works
1484 * well enough in practice; in the face of the horrible PCIe<->PCI-X conditions
1485 * for taking ownership all we can really do is close our eyes and hope...
1486 */
1487 static int get_msi_id_cb(struct pci_dev *pdev, u16 alias, void *data)
1488 {
1489 u32 *pa = data;
1490 u8 bus = PCI_BUS_NUM(*pa);
1491
1492 if (pdev->bus->number != bus || PCI_BUS_NUM(alias) != bus)
1493 *pa = alias;
1494
1495 return 0;
1496 }
1497
1498 /**
1499 * pci_msi_domain_get_msi_rid - Get the MSI requester id (RID)
1500 * @domain: The interrupt domain
1501 * @pdev: The PCI device.
1502 *
1503 * The RID for a device is formed from the alias, with a firmware
1504 * supplied mapping applied
1505 *
1506 * Returns: The RID.
1507 */
1508 u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev)
1509 {
1510 struct device_node *of_node;
1511 u32 rid = PCI_DEVID(pdev->bus->number, pdev->devfn);
1512
1513 pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);
1514
1515 of_node = irq_domain_get_of_node(domain);
1516 rid = of_node ? of_msi_map_rid(&pdev->dev, of_node, rid) :
1517 iort_msi_map_rid(&pdev->dev, rid);
1518
1519 return rid;
1520 }
1521
1522 /**
1523 * pci_msi_get_device_domain - Get the MSI domain for a given PCI device
1524 * @pdev: The PCI device
1525 *
1526 * Use the firmware data to find a device-specific MSI domain
1527 * (i.e. not one that is set as a default).
1528 *
1529 * Returns: The corresponding MSI domain or NULL if none has been found.
1530 */
1531 struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev)
1532 {
1533 struct irq_domain *dom;
1534 u32 rid = PCI_DEVID(pdev->bus->number, pdev->devfn);
1535
1536 pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);
1537 dom = of_msi_map_get_device_domain(&pdev->dev, rid);
1538 if (!dom)
1539 dom = iort_get_device_domain(&pdev->dev, rid);
1540 return dom;
1541 }
1542 #endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */