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
pci_msi_setup_msi_irqs(struct pci_dev * dev,int nvec,int type)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 
pci_msi_teardown_msi_irqs(struct pci_dev * dev)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 
arch_setup_msi_irq(struct pci_dev * dev,struct msi_desc * desc)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 
arch_teardown_msi_irq(unsigned int irq)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 
arch_setup_msi_irqs(struct pci_dev * dev,int nvec,int type)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  */
default_teardown_msi_irqs(struct pci_dev * dev)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 
arch_teardown_msi_irqs(struct pci_dev * dev)131 void __weak arch_teardown_msi_irqs(struct pci_dev *dev)
132 {
133 	return default_teardown_msi_irqs(dev);
134 }
135 
default_restore_msi_irq(struct pci_dev * dev,int irq)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 
arch_restore_msi_irqs(struct pci_dev * dev)154 void __weak arch_restore_msi_irqs(struct pci_dev *dev)
155 {
156 	return default_restore_msi_irqs(dev);
157 }
158 
msi_mask(unsigned x)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  */
__pci_msi_desc_mask_irq(struct msi_desc * desc,u32 mask,u32 flag)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 
msi_mask_irq(struct msi_desc * desc,u32 mask,u32 flag)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 
pci_msix_desc_addr(struct msi_desc * desc)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  */
__pci_msix_desc_mask_irq(struct msi_desc * desc,u32 flag)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 
msix_mask_irq(struct msi_desc * desc,u32 flag)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 
msi_set_mask_bit(struct irq_data * data,u32 flag)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  */
pci_msi_mask_irq(struct irq_data * data)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  */
pci_msi_unmask_irq(struct irq_data * data)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 
default_restore_msi_irqs(struct pci_dev * dev)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 
__pci_read_msi_msg(struct msi_desc * entry,struct msi_msg * msg)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 
__pci_write_msi_msg(struct msi_desc * entry,struct msi_msg * msg)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 
pci_write_msi_msg(unsigned int irq,struct msi_msg * msg)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 
free_msi_irqs(struct pci_dev * dev)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 
pci_intx_for_msi(struct pci_dev * dev,int enable)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 
__pci_restore_msi_state(struct pci_dev * dev)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 
__pci_restore_msix_state(struct pci_dev * dev)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 
pci_restore_msi_state(struct pci_dev * dev)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 
msi_mode_show(struct device * dev,struct device_attribute * attr,char * buf)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 
populate_msi_sysfs(struct pci_dev * pdev)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 *
msi_setup_entry(struct pci_dev * dev,int nvec,const struct irq_affinity * affd)535 msi_setup_entry(struct pci_dev *dev, int nvec, const struct irq_affinity *affd)
536 {
537 	struct cpumask *masks = NULL;
538 	struct msi_desc *entry;
539 	u16 control;
540 
541 	if (affd)
542 		masks = irq_create_affinity_masks(nvec, affd);
543 
544 
545 	/* MSI Entry Initialization */
546 	entry = alloc_msi_entry(&dev->dev, nvec, masks);
547 	if (!entry)
548 		goto out;
549 
550 	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
551 
552 	entry->msi_attrib.is_msix	= 0;
553 	entry->msi_attrib.is_64		= !!(control & PCI_MSI_FLAGS_64BIT);
554 	entry->msi_attrib.entry_nr	= 0;
555 	entry->msi_attrib.maskbit	= !!(control & PCI_MSI_FLAGS_MASKBIT);
556 	entry->msi_attrib.default_irq	= dev->irq;	/* Save IOAPIC IRQ */
557 	entry->msi_attrib.multi_cap	= (control & PCI_MSI_FLAGS_QMASK) >> 1;
558 	entry->msi_attrib.multiple	= ilog2(__roundup_pow_of_two(nvec));
559 
560 	if (control & PCI_MSI_FLAGS_64BIT)
561 		entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_64;
562 	else
563 		entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_32;
564 
565 	/* Save the initial mask status */
566 	if (entry->msi_attrib.maskbit)
567 		pci_read_config_dword(dev, entry->mask_pos, &entry->masked);
568 
569 out:
570 	kfree(masks);
571 	return entry;
572 }
573 
msi_verify_entries(struct pci_dev * dev)574 static int msi_verify_entries(struct pci_dev *dev)
575 {
576 	struct msi_desc *entry;
577 
578 	for_each_pci_msi_entry(entry, dev) {
579 		if (!dev->no_64bit_msi || !entry->msg.address_hi)
580 			continue;
581 		pci_err(dev, "Device has broken 64-bit MSI but arch"
582 			" tried to assign one above 4G\n");
583 		return -EIO;
584 	}
585 	return 0;
586 }
587 
588 /**
589  * msi_capability_init - configure device's MSI capability structure
590  * @dev: pointer to the pci_dev data structure of MSI device function
591  * @nvec: number of interrupts to allocate
592  * @affd: description of automatic irq affinity assignments (may be %NULL)
593  *
594  * Setup the MSI capability structure of the device with the requested
595  * number of interrupts.  A return value of zero indicates the successful
596  * setup of an entry with the new MSI irq.  A negative return value indicates
597  * an error, and a positive return value indicates the number of interrupts
598  * which could have been allocated.
599  */
msi_capability_init(struct pci_dev * dev,int nvec,const struct irq_affinity * affd)600 static int msi_capability_init(struct pci_dev *dev, int nvec,
601 			       const struct irq_affinity *affd)
602 {
603 	struct msi_desc *entry;
604 	int ret;
605 	unsigned mask;
606 
607 	pci_msi_set_enable(dev, 0);	/* Disable MSI during set up */
608 
609 	entry = msi_setup_entry(dev, nvec, affd);
610 	if (!entry)
611 		return -ENOMEM;
612 
613 	/* All MSIs are unmasked by default, Mask them all */
614 	mask = msi_mask(entry->msi_attrib.multi_cap);
615 	msi_mask_irq(entry, mask, mask);
616 
617 	list_add_tail(&entry->list, dev_to_msi_list(&dev->dev));
618 
619 	/* Configure MSI capability structure */
620 	ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSI);
621 	if (ret) {
622 		msi_mask_irq(entry, mask, ~mask);
623 		free_msi_irqs(dev);
624 		return ret;
625 	}
626 
627 	ret = msi_verify_entries(dev);
628 	if (ret) {
629 		msi_mask_irq(entry, mask, ~mask);
630 		free_msi_irqs(dev);
631 		return ret;
632 	}
633 
634 	ret = populate_msi_sysfs(dev);
635 	if (ret) {
636 		msi_mask_irq(entry, mask, ~mask);
637 		free_msi_irqs(dev);
638 		return ret;
639 	}
640 
641 	/* Set MSI enabled bits	 */
642 	pci_intx_for_msi(dev, 0);
643 	pci_msi_set_enable(dev, 1);
644 	dev->msi_enabled = 1;
645 
646 	pcibios_free_irq(dev);
647 	dev->irq = entry->irq;
648 	return 0;
649 }
650 
msix_map_region(struct pci_dev * dev,unsigned nr_entries)651 static void __iomem *msix_map_region(struct pci_dev *dev, unsigned nr_entries)
652 {
653 	resource_size_t phys_addr;
654 	u32 table_offset;
655 	unsigned long flags;
656 	u8 bir;
657 
658 	pci_read_config_dword(dev, dev->msix_cap + PCI_MSIX_TABLE,
659 			      &table_offset);
660 	bir = (u8)(table_offset & PCI_MSIX_TABLE_BIR);
661 	flags = pci_resource_flags(dev, bir);
662 	if (!flags || (flags & IORESOURCE_UNSET))
663 		return NULL;
664 
665 	table_offset &= PCI_MSIX_TABLE_OFFSET;
666 	phys_addr = pci_resource_start(dev, bir) + table_offset;
667 
668 	return ioremap_nocache(phys_addr, nr_entries * PCI_MSIX_ENTRY_SIZE);
669 }
670 
msix_setup_entries(struct pci_dev * dev,void __iomem * base,struct msix_entry * entries,int nvec,const struct irq_affinity * affd)671 static int msix_setup_entries(struct pci_dev *dev, void __iomem *base,
672 			      struct msix_entry *entries, int nvec,
673 			      const struct irq_affinity *affd)
674 {
675 	struct cpumask *curmsk, *masks = NULL;
676 	struct msi_desc *entry;
677 	int ret, i;
678 
679 	if (affd)
680 		masks = irq_create_affinity_masks(nvec, affd);
681 
682 	for (i = 0, curmsk = masks; i < nvec; i++) {
683 		entry = alloc_msi_entry(&dev->dev, 1, curmsk);
684 		if (!entry) {
685 			if (!i)
686 				iounmap(base);
687 			else
688 				free_msi_irqs(dev);
689 			/* No enough memory. Don't try again */
690 			ret = -ENOMEM;
691 			goto out;
692 		}
693 
694 		entry->msi_attrib.is_msix	= 1;
695 		entry->msi_attrib.is_64		= 1;
696 		if (entries)
697 			entry->msi_attrib.entry_nr = entries[i].entry;
698 		else
699 			entry->msi_attrib.entry_nr = i;
700 		entry->msi_attrib.default_irq	= dev->irq;
701 		entry->mask_base		= base;
702 
703 		list_add_tail(&entry->list, dev_to_msi_list(&dev->dev));
704 		if (masks)
705 			curmsk++;
706 	}
707 	ret = 0;
708 out:
709 	kfree(masks);
710 	return ret;
711 }
712 
msix_program_entries(struct pci_dev * dev,struct msix_entry * entries)713 static void msix_program_entries(struct pci_dev *dev,
714 				 struct msix_entry *entries)
715 {
716 	struct msi_desc *entry;
717 	int i = 0;
718 
719 	for_each_pci_msi_entry(entry, dev) {
720 		if (entries)
721 			entries[i++].vector = entry->irq;
722 		entry->masked = readl(pci_msix_desc_addr(entry) +
723 				PCI_MSIX_ENTRY_VECTOR_CTRL);
724 		msix_mask_irq(entry, 1);
725 	}
726 }
727 
728 /**
729  * msix_capability_init - configure device's MSI-X capability
730  * @dev: pointer to the pci_dev data structure of MSI-X device function
731  * @entries: pointer to an array of struct msix_entry entries
732  * @nvec: number of @entries
733  * @affd: Optional pointer to enable automatic affinity assignement
734  *
735  * Setup the MSI-X capability structure of device function with a
736  * single MSI-X irq. A return of zero indicates the successful setup of
737  * requested MSI-X entries with allocated irqs or non-zero for otherwise.
738  **/
msix_capability_init(struct pci_dev * dev,struct msix_entry * entries,int nvec,const struct irq_affinity * affd)739 static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries,
740 				int nvec, const struct irq_affinity *affd)
741 {
742 	int ret;
743 	u16 control;
744 	void __iomem *base;
745 
746 	/* Ensure MSI-X is disabled while it is set up */
747 	pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0);
748 
749 	pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &control);
750 	/* Request & Map MSI-X table region */
751 	base = msix_map_region(dev, msix_table_size(control));
752 	if (!base)
753 		return -ENOMEM;
754 
755 	ret = msix_setup_entries(dev, base, entries, nvec, affd);
756 	if (ret)
757 		return ret;
758 
759 	ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSIX);
760 	if (ret)
761 		goto out_avail;
762 
763 	/* Check if all MSI entries honor device restrictions */
764 	ret = msi_verify_entries(dev);
765 	if (ret)
766 		goto out_free;
767 
768 	/*
769 	 * Some devices require MSI-X to be enabled before we can touch the
770 	 * MSI-X registers.  We need to mask all the vectors to prevent
771 	 * interrupts coming in before they're fully set up.
772 	 */
773 	pci_msix_clear_and_set_ctrl(dev, 0,
774 				PCI_MSIX_FLAGS_MASKALL | PCI_MSIX_FLAGS_ENABLE);
775 
776 	msix_program_entries(dev, entries);
777 
778 	ret = populate_msi_sysfs(dev);
779 	if (ret)
780 		goto out_free;
781 
782 	/* Set MSI-X enabled bits and unmask the function */
783 	pci_intx_for_msi(dev, 0);
784 	dev->msix_enabled = 1;
785 	pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL, 0);
786 
787 	pcibios_free_irq(dev);
788 	return 0;
789 
790 out_avail:
791 	if (ret < 0) {
792 		/*
793 		 * If we had some success, report the number of irqs
794 		 * we succeeded in setting up.
795 		 */
796 		struct msi_desc *entry;
797 		int avail = 0;
798 
799 		for_each_pci_msi_entry(entry, dev) {
800 			if (entry->irq != 0)
801 				avail++;
802 		}
803 		if (avail != 0)
804 			ret = avail;
805 	}
806 
807 out_free:
808 	free_msi_irqs(dev);
809 
810 	return ret;
811 }
812 
813 /**
814  * pci_msi_supported - check whether MSI may be enabled on a device
815  * @dev: pointer to the pci_dev data structure of MSI device function
816  * @nvec: how many MSIs have been requested ?
817  *
818  * Look at global flags, the device itself, and its parent buses
819  * to determine if MSI/-X are supported for the device. If MSI/-X is
820  * supported return 1, else return 0.
821  **/
pci_msi_supported(struct pci_dev * dev,int nvec)822 static int pci_msi_supported(struct pci_dev *dev, int nvec)
823 {
824 	struct pci_bus *bus;
825 
826 	/* MSI must be globally enabled and supported by the device */
827 	if (!pci_msi_enable)
828 		return 0;
829 
830 	if (!dev || dev->no_msi || dev->current_state != PCI_D0)
831 		return 0;
832 
833 	/*
834 	 * You can't ask to have 0 or less MSIs configured.
835 	 *  a) it's stupid ..
836 	 *  b) the list manipulation code assumes nvec >= 1.
837 	 */
838 	if (nvec < 1)
839 		return 0;
840 
841 	/*
842 	 * Any bridge which does NOT route MSI transactions from its
843 	 * secondary bus to its primary bus must set NO_MSI flag on
844 	 * the secondary pci_bus.
845 	 * We expect only arch-specific PCI host bus controller driver
846 	 * or quirks for specific PCI bridges to be setting NO_MSI.
847 	 */
848 	for (bus = dev->bus; bus; bus = bus->parent)
849 		if (bus->bus_flags & PCI_BUS_FLAGS_NO_MSI)
850 			return 0;
851 
852 	return 1;
853 }
854 
855 /**
856  * pci_msi_vec_count - Return the number of MSI vectors a device can send
857  * @dev: device to report about
858  *
859  * This function returns the number of MSI vectors a device requested via
860  * Multiple Message Capable register. It returns a negative errno if the
861  * device is not capable sending MSI interrupts. Otherwise, the call succeeds
862  * and returns a power of two, up to a maximum of 2^5 (32), according to the
863  * MSI specification.
864  **/
pci_msi_vec_count(struct pci_dev * dev)865 int pci_msi_vec_count(struct pci_dev *dev)
866 {
867 	int ret;
868 	u16 msgctl;
869 
870 	if (!dev->msi_cap)
871 		return -EINVAL;
872 
873 	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &msgctl);
874 	ret = 1 << ((msgctl & PCI_MSI_FLAGS_QMASK) >> 1);
875 
876 	return ret;
877 }
878 EXPORT_SYMBOL(pci_msi_vec_count);
879 
pci_msi_shutdown(struct pci_dev * dev)880 static void pci_msi_shutdown(struct pci_dev *dev)
881 {
882 	struct msi_desc *desc;
883 	u32 mask;
884 
885 	if (!pci_msi_enable || !dev || !dev->msi_enabled)
886 		return;
887 
888 	BUG_ON(list_empty(dev_to_msi_list(&dev->dev)));
889 	desc = first_pci_msi_entry(dev);
890 
891 	pci_msi_set_enable(dev, 0);
892 	pci_intx_for_msi(dev, 1);
893 	dev->msi_enabled = 0;
894 
895 	/* Return the device with MSI unmasked as initial states */
896 	mask = msi_mask(desc->msi_attrib.multi_cap);
897 	/* Keep cached state to be restored */
898 	__pci_msi_desc_mask_irq(desc, mask, ~mask);
899 
900 	/* Restore dev->irq to its default pin-assertion irq */
901 	dev->irq = desc->msi_attrib.default_irq;
902 	pcibios_alloc_irq(dev);
903 }
904 
pci_disable_msi(struct pci_dev * dev)905 void pci_disable_msi(struct pci_dev *dev)
906 {
907 	if (!pci_msi_enable || !dev || !dev->msi_enabled)
908 		return;
909 
910 	pci_msi_shutdown(dev);
911 	free_msi_irqs(dev);
912 }
913 EXPORT_SYMBOL(pci_disable_msi);
914 
915 /**
916  * pci_msix_vec_count - return the number of device's MSI-X table entries
917  * @dev: pointer to the pci_dev data structure of MSI-X device function
918  * This function returns the number of device's MSI-X table entries and
919  * therefore the number of MSI-X vectors device is capable of sending.
920  * It returns a negative errno if the device is not capable of sending MSI-X
921  * interrupts.
922  **/
pci_msix_vec_count(struct pci_dev * dev)923 int pci_msix_vec_count(struct pci_dev *dev)
924 {
925 	u16 control;
926 
927 	if (!dev->msix_cap)
928 		return -EINVAL;
929 
930 	pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &control);
931 	return msix_table_size(control);
932 }
933 EXPORT_SYMBOL(pci_msix_vec_count);
934 
__pci_enable_msix(struct pci_dev * dev,struct msix_entry * entries,int nvec,const struct irq_affinity * affd)935 static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries,
936 			     int nvec, const struct irq_affinity *affd)
937 {
938 	int nr_entries;
939 	int i, j;
940 
941 	if (!pci_msi_supported(dev, nvec))
942 		return -EINVAL;
943 
944 	nr_entries = pci_msix_vec_count(dev);
945 	if (nr_entries < 0)
946 		return nr_entries;
947 	if (nvec > nr_entries)
948 		return nr_entries;
949 
950 	if (entries) {
951 		/* Check for any invalid entries */
952 		for (i = 0; i < nvec; i++) {
953 			if (entries[i].entry >= nr_entries)
954 				return -EINVAL;		/* invalid entry */
955 			for (j = i + 1; j < nvec; j++) {
956 				if (entries[i].entry == entries[j].entry)
957 					return -EINVAL;	/* duplicate entry */
958 			}
959 		}
960 	}
961 	WARN_ON(!!dev->msix_enabled);
962 
963 	/* Check whether driver already requested for MSI irq */
964 	if (dev->msi_enabled) {
965 		pci_info(dev, "can't enable MSI-X (MSI IRQ already assigned)\n");
966 		return -EINVAL;
967 	}
968 	return msix_capability_init(dev, entries, nvec, affd);
969 }
970 
pci_msix_shutdown(struct pci_dev * dev)971 static void pci_msix_shutdown(struct pci_dev *dev)
972 {
973 	struct msi_desc *entry;
974 
975 	if (!pci_msi_enable || !dev || !dev->msix_enabled)
976 		return;
977 
978 	if (pci_dev_is_disconnected(dev)) {
979 		dev->msix_enabled = 0;
980 		return;
981 	}
982 
983 	/* Return the device with MSI-X masked as initial states */
984 	for_each_pci_msi_entry(entry, dev) {
985 		/* Keep cached states to be restored */
986 		__pci_msix_desc_mask_irq(entry, 1);
987 	}
988 
989 	pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0);
990 	pci_intx_for_msi(dev, 1);
991 	dev->msix_enabled = 0;
992 	pcibios_alloc_irq(dev);
993 }
994 
pci_disable_msix(struct pci_dev * dev)995 void pci_disable_msix(struct pci_dev *dev)
996 {
997 	if (!pci_msi_enable || !dev || !dev->msix_enabled)
998 		return;
999 
1000 	pci_msix_shutdown(dev);
1001 	free_msi_irqs(dev);
1002 }
1003 EXPORT_SYMBOL(pci_disable_msix);
1004 
pci_no_msi(void)1005 void pci_no_msi(void)
1006 {
1007 	pci_msi_enable = 0;
1008 }
1009 
1010 /**
1011  * pci_msi_enabled - is MSI enabled?
1012  *
1013  * Returns true if MSI has not been disabled by the command-line option
1014  * pci=nomsi.
1015  **/
pci_msi_enabled(void)1016 int pci_msi_enabled(void)
1017 {
1018 	return pci_msi_enable;
1019 }
1020 EXPORT_SYMBOL(pci_msi_enabled);
1021 
__pci_enable_msi_range(struct pci_dev * dev,int minvec,int maxvec,const struct irq_affinity * affd)1022 static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
1023 				  const struct irq_affinity *affd)
1024 {
1025 	int nvec;
1026 	int rc;
1027 
1028 	if (!pci_msi_supported(dev, minvec))
1029 		return -EINVAL;
1030 
1031 	WARN_ON(!!dev->msi_enabled);
1032 
1033 	/* Check whether driver already requested MSI-X irqs */
1034 	if (dev->msix_enabled) {
1035 		pci_info(dev, "can't enable MSI (MSI-X already enabled)\n");
1036 		return -EINVAL;
1037 	}
1038 
1039 	if (maxvec < minvec)
1040 		return -ERANGE;
1041 
1042 	nvec = pci_msi_vec_count(dev);
1043 	if (nvec < 0)
1044 		return nvec;
1045 	if (nvec < minvec)
1046 		return -ENOSPC;
1047 
1048 	if (nvec > maxvec)
1049 		nvec = maxvec;
1050 
1051 	for (;;) {
1052 		if (affd) {
1053 			nvec = irq_calc_affinity_vectors(minvec, nvec, affd);
1054 			if (nvec < minvec)
1055 				return -ENOSPC;
1056 		}
1057 
1058 		rc = msi_capability_init(dev, nvec, affd);
1059 		if (rc == 0)
1060 			return nvec;
1061 
1062 		if (rc < 0)
1063 			return rc;
1064 		if (rc < minvec)
1065 			return -ENOSPC;
1066 
1067 		nvec = rc;
1068 	}
1069 }
1070 
1071 /* deprecated, don't use */
pci_enable_msi(struct pci_dev * dev)1072 int pci_enable_msi(struct pci_dev *dev)
1073 {
1074 	int rc = __pci_enable_msi_range(dev, 1, 1, NULL);
1075 	if (rc < 0)
1076 		return rc;
1077 	return 0;
1078 }
1079 EXPORT_SYMBOL(pci_enable_msi);
1080 
__pci_enable_msix_range(struct pci_dev * dev,struct msix_entry * entries,int minvec,int maxvec,const struct irq_affinity * affd)1081 static int __pci_enable_msix_range(struct pci_dev *dev,
1082 				   struct msix_entry *entries, int minvec,
1083 				   int maxvec, const struct irq_affinity *affd)
1084 {
1085 	int rc, nvec = maxvec;
1086 
1087 	if (maxvec < minvec)
1088 		return -ERANGE;
1089 
1090 	for (;;) {
1091 		if (affd) {
1092 			nvec = irq_calc_affinity_vectors(minvec, nvec, affd);
1093 			if (nvec < minvec)
1094 				return -ENOSPC;
1095 		}
1096 
1097 		rc = __pci_enable_msix(dev, entries, nvec, affd);
1098 		if (rc == 0)
1099 			return nvec;
1100 
1101 		if (rc < 0)
1102 			return rc;
1103 		if (rc < minvec)
1104 			return -ENOSPC;
1105 
1106 		nvec = rc;
1107 	}
1108 }
1109 
1110 /**
1111  * pci_enable_msix_range - configure device's MSI-X capability structure
1112  * @dev: pointer to the pci_dev data structure of MSI-X device function
1113  * @entries: pointer to an array of MSI-X entries
1114  * @minvec: minimum number of MSI-X irqs requested
1115  * @maxvec: maximum number of MSI-X irqs requested
1116  *
1117  * Setup the MSI-X capability structure of device function with a maximum
1118  * possible number of interrupts in the range between @minvec and @maxvec
1119  * upon its software driver call to request for MSI-X mode enabled on its
1120  * hardware device function. It returns a negative errno if an error occurs.
1121  * If it succeeds, it returns the actual number of interrupts allocated and
1122  * indicates the successful configuration of MSI-X capability structure
1123  * with new allocated MSI-X interrupts.
1124  **/
pci_enable_msix_range(struct pci_dev * dev,struct msix_entry * entries,int minvec,int maxvec)1125 int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries,
1126 		int minvec, int maxvec)
1127 {
1128 	return __pci_enable_msix_range(dev, entries, minvec, maxvec, NULL);
1129 }
1130 EXPORT_SYMBOL(pci_enable_msix_range);
1131 
1132 /**
1133  * pci_alloc_irq_vectors_affinity - allocate multiple IRQs for a device
1134  * @dev:		PCI device to operate on
1135  * @min_vecs:		minimum number of vectors required (must be >= 1)
1136  * @max_vecs:		maximum (desired) number of vectors
1137  * @flags:		flags or quirks for the allocation
1138  * @affd:		optional description of the affinity requirements
1139  *
1140  * Allocate up to @max_vecs interrupt vectors for @dev, using MSI-X or MSI
1141  * vectors if available, and fall back to a single legacy vector
1142  * if neither is available.  Return the number of vectors allocated,
1143  * (which might be smaller than @max_vecs) if successful, or a negative
1144  * error code on error. If less than @min_vecs interrupt vectors are
1145  * available for @dev the function will fail with -ENOSPC.
1146  *
1147  * To get the Linux IRQ number used for a vector that can be passed to
1148  * request_irq() use the pci_irq_vector() helper.
1149  */
pci_alloc_irq_vectors_affinity(struct pci_dev * dev,unsigned int min_vecs,unsigned int max_vecs,unsigned int flags,const struct irq_affinity * affd)1150 int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
1151 				   unsigned int max_vecs, unsigned int flags,
1152 				   const struct irq_affinity *affd)
1153 {
1154 	static const struct irq_affinity msi_default_affd;
1155 	int vecs = -ENOSPC;
1156 
1157 	if (flags & PCI_IRQ_AFFINITY) {
1158 		if (!affd)
1159 			affd = &msi_default_affd;
1160 	} else {
1161 		if (WARN_ON(affd))
1162 			affd = NULL;
1163 	}
1164 
1165 	if (flags & PCI_IRQ_MSIX) {
1166 		vecs = __pci_enable_msix_range(dev, NULL, min_vecs, max_vecs,
1167 				affd);
1168 		if (vecs > 0)
1169 			return vecs;
1170 	}
1171 
1172 	if (flags & PCI_IRQ_MSI) {
1173 		vecs = __pci_enable_msi_range(dev, min_vecs, max_vecs, affd);
1174 		if (vecs > 0)
1175 			return vecs;
1176 	}
1177 
1178 	/* use legacy irq if allowed */
1179 	if (flags & PCI_IRQ_LEGACY) {
1180 		if (min_vecs == 1 && dev->irq) {
1181 			pci_intx(dev, 1);
1182 			return 1;
1183 		}
1184 	}
1185 
1186 	return vecs;
1187 }
1188 EXPORT_SYMBOL(pci_alloc_irq_vectors_affinity);
1189 
1190 /**
1191  * pci_free_irq_vectors - free previously allocated IRQs for a device
1192  * @dev:		PCI device to operate on
1193  *
1194  * Undoes the allocations and enabling in pci_alloc_irq_vectors().
1195  */
pci_free_irq_vectors(struct pci_dev * dev)1196 void pci_free_irq_vectors(struct pci_dev *dev)
1197 {
1198 	pci_disable_msix(dev);
1199 	pci_disable_msi(dev);
1200 }
1201 EXPORT_SYMBOL(pci_free_irq_vectors);
1202 
1203 /**
1204  * pci_irq_vector - return Linux IRQ number of a device vector
1205  * @dev: PCI device to operate on
1206  * @nr: device-relative interrupt vector index (0-based).
1207  */
pci_irq_vector(struct pci_dev * dev,unsigned int nr)1208 int pci_irq_vector(struct pci_dev *dev, unsigned int nr)
1209 {
1210 	if (dev->msix_enabled) {
1211 		struct msi_desc *entry;
1212 		int i = 0;
1213 
1214 		for_each_pci_msi_entry(entry, dev) {
1215 			if (i == nr)
1216 				return entry->irq;
1217 			i++;
1218 		}
1219 		WARN_ON_ONCE(1);
1220 		return -EINVAL;
1221 	}
1222 
1223 	if (dev->msi_enabled) {
1224 		struct msi_desc *entry = first_pci_msi_entry(dev);
1225 
1226 		if (WARN_ON_ONCE(nr >= entry->nvec_used))
1227 			return -EINVAL;
1228 	} else {
1229 		if (WARN_ON_ONCE(nr > 0))
1230 			return -EINVAL;
1231 	}
1232 
1233 	return dev->irq + nr;
1234 }
1235 EXPORT_SYMBOL(pci_irq_vector);
1236 
1237 /**
1238  * pci_irq_get_affinity - return the affinity of a particular msi vector
1239  * @dev:	PCI device to operate on
1240  * @nr:		device-relative interrupt vector index (0-based).
1241  */
pci_irq_get_affinity(struct pci_dev * dev,int nr)1242 const struct cpumask *pci_irq_get_affinity(struct pci_dev *dev, int nr)
1243 {
1244 	if (dev->msix_enabled) {
1245 		struct msi_desc *entry;
1246 		int i = 0;
1247 
1248 		for_each_pci_msi_entry(entry, dev) {
1249 			if (i == nr)
1250 				return entry->affinity;
1251 			i++;
1252 		}
1253 		WARN_ON_ONCE(1);
1254 		return NULL;
1255 	} else if (dev->msi_enabled) {
1256 		struct msi_desc *entry = first_pci_msi_entry(dev);
1257 
1258 		if (WARN_ON_ONCE(!entry || !entry->affinity ||
1259 				 nr >= entry->nvec_used))
1260 			return NULL;
1261 
1262 		return &entry->affinity[nr];
1263 	} else {
1264 		return cpu_possible_mask;
1265 	}
1266 }
1267 EXPORT_SYMBOL(pci_irq_get_affinity);
1268 
1269 /**
1270  * pci_irq_get_node - return the numa node of a particular msi vector
1271  * @pdev:	PCI device to operate on
1272  * @vec:	device-relative interrupt vector index (0-based).
1273  */
pci_irq_get_node(struct pci_dev * pdev,int vec)1274 int pci_irq_get_node(struct pci_dev *pdev, int vec)
1275 {
1276 	const struct cpumask *mask;
1277 
1278 	mask = pci_irq_get_affinity(pdev, vec);
1279 	if (mask)
1280 		return local_memory_node(cpu_to_node(cpumask_first(mask)));
1281 	return dev_to_node(&pdev->dev);
1282 }
1283 EXPORT_SYMBOL(pci_irq_get_node);
1284 
msi_desc_to_pci_dev(struct msi_desc * desc)1285 struct pci_dev *msi_desc_to_pci_dev(struct msi_desc *desc)
1286 {
1287 	return to_pci_dev(desc->dev);
1288 }
1289 EXPORT_SYMBOL(msi_desc_to_pci_dev);
1290 
msi_desc_to_pci_sysdata(struct msi_desc * desc)1291 void *msi_desc_to_pci_sysdata(struct msi_desc *desc)
1292 {
1293 	struct pci_dev *dev = msi_desc_to_pci_dev(desc);
1294 
1295 	return dev->bus->sysdata;
1296 }
1297 EXPORT_SYMBOL_GPL(msi_desc_to_pci_sysdata);
1298 
1299 #ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
1300 /**
1301  * pci_msi_domain_write_msg - Helper to write MSI message to PCI config space
1302  * @irq_data:	Pointer to interrupt data of the MSI interrupt
1303  * @msg:	Pointer to the message
1304  */
pci_msi_domain_write_msg(struct irq_data * irq_data,struct msi_msg * msg)1305 void pci_msi_domain_write_msg(struct irq_data *irq_data, struct msi_msg *msg)
1306 {
1307 	struct msi_desc *desc = irq_data_get_msi_desc(irq_data);
1308 
1309 	/*
1310 	 * For MSI-X desc->irq is always equal to irq_data->irq. For
1311 	 * MSI only the first interrupt of MULTI MSI passes the test.
1312 	 */
1313 	if (desc->irq == irq_data->irq)
1314 		__pci_write_msi_msg(desc, msg);
1315 }
1316 
1317 /**
1318  * pci_msi_domain_calc_hwirq - Generate a unique ID for an MSI source
1319  * @dev:	Pointer to the PCI device
1320  * @desc:	Pointer to the msi descriptor
1321  *
1322  * The ID number is only used within the irqdomain.
1323  */
pci_msi_domain_calc_hwirq(struct pci_dev * dev,struct msi_desc * desc)1324 irq_hw_number_t pci_msi_domain_calc_hwirq(struct pci_dev *dev,
1325 					  struct msi_desc *desc)
1326 {
1327 	return (irq_hw_number_t)desc->msi_attrib.entry_nr |
1328 		PCI_DEVID(dev->bus->number, dev->devfn) << 11 |
1329 		(pci_domain_nr(dev->bus) & 0xFFFFFFFF) << 27;
1330 }
1331 
pci_msi_desc_is_multi_msi(struct msi_desc * desc)1332 static inline bool pci_msi_desc_is_multi_msi(struct msi_desc *desc)
1333 {
1334 	return !desc->msi_attrib.is_msix && desc->nvec_used > 1;
1335 }
1336 
1337 /**
1338  * pci_msi_domain_check_cap - Verify that @domain supports the capabilities for @dev
1339  * @domain:	The interrupt domain to check
1340  * @info:	The domain info for verification
1341  * @dev:	The device to check
1342  *
1343  * Returns:
1344  *  0 if the functionality is supported
1345  *  1 if Multi MSI is requested, but the domain does not support it
1346  *  -ENOTSUPP otherwise
1347  */
pci_msi_domain_check_cap(struct irq_domain * domain,struct msi_domain_info * info,struct device * dev)1348 int pci_msi_domain_check_cap(struct irq_domain *domain,
1349 			     struct msi_domain_info *info, struct device *dev)
1350 {
1351 	struct msi_desc *desc = first_pci_msi_entry(to_pci_dev(dev));
1352 
1353 	/* Special handling to support __pci_enable_msi_range() */
1354 	if (pci_msi_desc_is_multi_msi(desc) &&
1355 	    !(info->flags & MSI_FLAG_MULTI_PCI_MSI))
1356 		return 1;
1357 	else if (desc->msi_attrib.is_msix && !(info->flags & MSI_FLAG_PCI_MSIX))
1358 		return -ENOTSUPP;
1359 
1360 	return 0;
1361 }
1362 
pci_msi_domain_handle_error(struct irq_domain * domain,struct msi_desc * desc,int error)1363 static int pci_msi_domain_handle_error(struct irq_domain *domain,
1364 				       struct msi_desc *desc, int error)
1365 {
1366 	/* Special handling to support __pci_enable_msi_range() */
1367 	if (pci_msi_desc_is_multi_msi(desc) && error == -ENOSPC)
1368 		return 1;
1369 
1370 	return error;
1371 }
1372 
1373 #ifdef GENERIC_MSI_DOMAIN_OPS
pci_msi_domain_set_desc(msi_alloc_info_t * arg,struct msi_desc * desc)1374 static void pci_msi_domain_set_desc(msi_alloc_info_t *arg,
1375 				    struct msi_desc *desc)
1376 {
1377 	arg->desc = desc;
1378 	arg->hwirq = pci_msi_domain_calc_hwirq(msi_desc_to_pci_dev(desc),
1379 					       desc);
1380 }
1381 #else
1382 #define pci_msi_domain_set_desc		NULL
1383 #endif
1384 
1385 static struct msi_domain_ops pci_msi_domain_ops_default = {
1386 	.set_desc	= pci_msi_domain_set_desc,
1387 	.msi_check	= pci_msi_domain_check_cap,
1388 	.handle_error	= pci_msi_domain_handle_error,
1389 };
1390 
pci_msi_domain_update_dom_ops(struct msi_domain_info * info)1391 static void pci_msi_domain_update_dom_ops(struct msi_domain_info *info)
1392 {
1393 	struct msi_domain_ops *ops = info->ops;
1394 
1395 	if (ops == NULL) {
1396 		info->ops = &pci_msi_domain_ops_default;
1397 	} else {
1398 		if (ops->set_desc == NULL)
1399 			ops->set_desc = pci_msi_domain_set_desc;
1400 		if (ops->msi_check == NULL)
1401 			ops->msi_check = pci_msi_domain_check_cap;
1402 		if (ops->handle_error == NULL)
1403 			ops->handle_error = pci_msi_domain_handle_error;
1404 	}
1405 }
1406 
pci_msi_domain_update_chip_ops(struct msi_domain_info * info)1407 static void pci_msi_domain_update_chip_ops(struct msi_domain_info *info)
1408 {
1409 	struct irq_chip *chip = info->chip;
1410 
1411 	BUG_ON(!chip);
1412 	if (!chip->irq_write_msi_msg)
1413 		chip->irq_write_msi_msg = pci_msi_domain_write_msg;
1414 	if (!chip->irq_mask)
1415 		chip->irq_mask = pci_msi_mask_irq;
1416 	if (!chip->irq_unmask)
1417 		chip->irq_unmask = pci_msi_unmask_irq;
1418 }
1419 
1420 /**
1421  * pci_msi_create_irq_domain - Create a MSI interrupt domain
1422  * @fwnode:	Optional fwnode of the interrupt controller
1423  * @info:	MSI domain info
1424  * @parent:	Parent irq domain
1425  *
1426  * Updates the domain and chip ops and creates a MSI interrupt domain.
1427  *
1428  * Returns:
1429  * A domain pointer or NULL in case of failure.
1430  */
pci_msi_create_irq_domain(struct fwnode_handle * fwnode,struct msi_domain_info * info,struct irq_domain * parent)1431 struct irq_domain *pci_msi_create_irq_domain(struct fwnode_handle *fwnode,
1432 					     struct msi_domain_info *info,
1433 					     struct irq_domain *parent)
1434 {
1435 	struct irq_domain *domain;
1436 
1437 	if (WARN_ON(info->flags & MSI_FLAG_LEVEL_CAPABLE))
1438 		info->flags &= ~MSI_FLAG_LEVEL_CAPABLE;
1439 
1440 	if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
1441 		pci_msi_domain_update_dom_ops(info);
1442 	if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
1443 		pci_msi_domain_update_chip_ops(info);
1444 
1445 	info->flags |= MSI_FLAG_ACTIVATE_EARLY;
1446 	if (IS_ENABLED(CONFIG_GENERIC_IRQ_RESERVATION_MODE))
1447 		info->flags |= MSI_FLAG_MUST_REACTIVATE;
1448 
1449 	/* PCI-MSI is oneshot-safe */
1450 	info->chip->flags |= IRQCHIP_ONESHOT_SAFE;
1451 
1452 	domain = msi_create_irq_domain(fwnode, info, parent);
1453 	if (!domain)
1454 		return NULL;
1455 
1456 	irq_domain_update_bus_token(domain, DOMAIN_BUS_PCI_MSI);
1457 	return domain;
1458 }
1459 EXPORT_SYMBOL_GPL(pci_msi_create_irq_domain);
1460 
1461 /*
1462  * Users of the generic MSI infrastructure expect a device to have a single ID,
1463  * so with DMA aliases we have to pick the least-worst compromise. Devices with
1464  * DMA phantom functions tend to still emit MSIs from the real function number,
1465  * so we ignore those and only consider topological aliases where either the
1466  * alias device or RID appears on a different bus number. We also make the
1467  * reasonable assumption that bridges are walked in an upstream direction (so
1468  * the last one seen wins), and the much braver assumption that the most likely
1469  * case is that of PCI->PCIe so we should always use the alias RID. This echoes
1470  * the logic from intel_irq_remapping's set_msi_sid(), which presumably works
1471  * well enough in practice; in the face of the horrible PCIe<->PCI-X conditions
1472  * for taking ownership all we can really do is close our eyes and hope...
1473  */
get_msi_id_cb(struct pci_dev * pdev,u16 alias,void * data)1474 static int get_msi_id_cb(struct pci_dev *pdev, u16 alias, void *data)
1475 {
1476 	u32 *pa = data;
1477 	u8 bus = PCI_BUS_NUM(*pa);
1478 
1479 	if (pdev->bus->number != bus || PCI_BUS_NUM(alias) != bus)
1480 		*pa = alias;
1481 
1482 	return 0;
1483 }
1484 
1485 /**
1486  * pci_msi_domain_get_msi_rid - Get the MSI requester id (RID)
1487  * @domain:	The interrupt domain
1488  * @pdev:	The PCI device.
1489  *
1490  * The RID for a device is formed from the alias, with a firmware
1491  * supplied mapping applied
1492  *
1493  * Returns: The RID.
1494  */
pci_msi_domain_get_msi_rid(struct irq_domain * domain,struct pci_dev * pdev)1495 u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev)
1496 {
1497 	struct device_node *of_node;
1498 	u32 rid = PCI_DEVID(pdev->bus->number, pdev->devfn);
1499 
1500 	pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);
1501 
1502 	of_node = irq_domain_get_of_node(domain);
1503 	rid = of_node ? of_msi_map_rid(&pdev->dev, of_node, rid) :
1504 			iort_msi_map_rid(&pdev->dev, rid);
1505 
1506 	return rid;
1507 }
1508 
1509 /**
1510  * pci_msi_get_device_domain - Get the MSI domain for a given PCI device
1511  * @pdev:	The PCI device
1512  *
1513  * Use the firmware data to find a device-specific MSI domain
1514  * (i.e. not one that is set as a default).
1515  *
1516  * Returns: The corresponding MSI domain or NULL if none has been found.
1517  */
pci_msi_get_device_domain(struct pci_dev * pdev)1518 struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev)
1519 {
1520 	struct irq_domain *dom;
1521 	u32 rid = PCI_DEVID(pdev->bus->number, pdev->devfn);
1522 
1523 	pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);
1524 	dom = of_msi_map_get_device_domain(&pdev->dev, rid);
1525 	if (!dom)
1526 		dom = iort_get_device_domain(&pdev->dev, rid);
1527 	return dom;
1528 }
1529 #endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */
1530