Line data Source code
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 : #include <linux/err.h>
10 : #include <linux/export.h>
11 : #include <linux/irq.h>
12 :
13 : #include "../pci.h"
14 : #include "msi.h"
15 :
16 : int pci_msi_enable = 1;
17 : int pci_msi_ignore_mask;
18 :
19 : /**
20 : * pci_msi_supported - check whether MSI may be enabled on a device
21 : * @dev: pointer to the pci_dev data structure of MSI device function
22 : * @nvec: how many MSIs have been requested?
23 : *
24 : * Look at global flags, the device itself, and its parent buses
25 : * to determine if MSI/-X are supported for the device. If MSI/-X is
26 : * supported return 1, else return 0.
27 : **/
28 : static int pci_msi_supported(struct pci_dev *dev, int nvec)
29 : {
30 : struct pci_bus *bus;
31 :
32 : /* MSI must be globally enabled and supported by the device */
33 0 : if (!pci_msi_enable)
34 : return 0;
35 :
36 0 : if (!dev || dev->no_msi)
37 : return 0;
38 :
39 : /*
40 : * You can't ask to have 0 or less MSIs configured.
41 : * a) it's stupid ..
42 : * b) the list manipulation code assumes nvec >= 1.
43 : */
44 0 : if (nvec < 1)
45 : return 0;
46 :
47 : /*
48 : * Any bridge which does NOT route MSI transactions from its
49 : * secondary bus to its primary bus must set NO_MSI flag on
50 : * the secondary pci_bus.
51 : *
52 : * The NO_MSI flag can either be set directly by:
53 : * - arch-specific PCI host bus controller drivers (deprecated)
54 : * - quirks for specific PCI bridges
55 : *
56 : * or indirectly by platform-specific PCI host bridge drivers by
57 : * advertising the 'msi_domain' property, which results in
58 : * the NO_MSI flag when no MSI domain is found for this bridge
59 : * at probe time.
60 : */
61 0 : for (bus = dev->bus; bus; bus = bus->parent)
62 0 : if (bus->bus_flags & PCI_BUS_FLAGS_NO_MSI)
63 : return 0;
64 :
65 : return 1;
66 : }
67 :
68 0 : static void pcim_msi_release(void *pcidev)
69 : {
70 0 : struct pci_dev *dev = pcidev;
71 :
72 0 : dev->is_msi_managed = false;
73 0 : pci_free_irq_vectors(dev);
74 0 : }
75 :
76 : /*
77 : * Needs to be separate from pcim_release to prevent an ordering problem
78 : * vs. msi_device_data_release() in the MSI core code.
79 : */
80 0 : static int pcim_setup_msi_release(struct pci_dev *dev)
81 : {
82 : int ret;
83 :
84 0 : if (!pci_is_managed(dev) || dev->is_msi_managed)
85 : return 0;
86 :
87 0 : ret = devm_add_action(&dev->dev, pcim_msi_release, dev);
88 0 : if (!ret)
89 0 : dev->is_msi_managed = true;
90 : return ret;
91 : }
92 :
93 : /*
94 : * Ordering vs. devres: msi device data has to be installed first so that
95 : * pcim_msi_release() is invoked before it on device release.
96 : */
97 0 : static int pci_setup_msi_context(struct pci_dev *dev)
98 : {
99 0 : int ret = msi_setup_device_data(&dev->dev);
100 :
101 0 : if (!ret)
102 0 : ret = pcim_setup_msi_release(dev);
103 0 : return ret;
104 : }
105 :
106 : /*
107 : * Helper functions for mask/unmask and MSI message handling
108 : */
109 :
110 0 : void pci_msi_update_mask(struct msi_desc *desc, u32 clear, u32 set)
111 : {
112 0 : raw_spinlock_t *lock = &to_pci_dev(desc->dev)->msi_lock;
113 : unsigned long flags;
114 :
115 0 : if (!desc->pci.msi_attrib.can_mask)
116 : return;
117 :
118 0 : raw_spin_lock_irqsave(lock, flags);
119 0 : desc->pci.msi_mask &= ~clear;
120 0 : desc->pci.msi_mask |= set;
121 0 : pci_write_config_dword(msi_desc_to_pci_dev(desc), desc->pci.mask_pos,
122 : desc->pci.msi_mask);
123 0 : raw_spin_unlock_irqrestore(lock, flags);
124 : }
125 :
126 : /**
127 : * pci_msi_mask_irq - Generic IRQ chip callback to mask PCI/MSI interrupts
128 : * @data: pointer to irqdata associated to that interrupt
129 : */
130 0 : void pci_msi_mask_irq(struct irq_data *data)
131 : {
132 0 : struct msi_desc *desc = irq_data_get_msi_desc(data);
133 :
134 0 : __pci_msi_mask_desc(desc, BIT(data->irq - desc->irq));
135 0 : }
136 : EXPORT_SYMBOL_GPL(pci_msi_mask_irq);
137 :
138 : /**
139 : * pci_msi_unmask_irq - Generic IRQ chip callback to unmask PCI/MSI interrupts
140 : * @data: pointer to irqdata associated to that interrupt
141 : */
142 0 : void pci_msi_unmask_irq(struct irq_data *data)
143 : {
144 0 : struct msi_desc *desc = irq_data_get_msi_desc(data);
145 :
146 0 : __pci_msi_unmask_desc(desc, BIT(data->irq - desc->irq));
147 0 : }
148 : EXPORT_SYMBOL_GPL(pci_msi_unmask_irq);
149 :
150 0 : void __pci_read_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
151 : {
152 0 : struct pci_dev *dev = msi_desc_to_pci_dev(entry);
153 :
154 0 : BUG_ON(dev->current_state != PCI_D0);
155 :
156 0 : if (entry->pci.msi_attrib.is_msix) {
157 0 : void __iomem *base = pci_msix_desc_addr(entry);
158 :
159 0 : if (WARN_ON_ONCE(entry->pci.msi_attrib.is_virtual))
160 : return;
161 :
162 0 : msg->address_lo = readl(base + PCI_MSIX_ENTRY_LOWER_ADDR);
163 0 : msg->address_hi = readl(base + PCI_MSIX_ENTRY_UPPER_ADDR);
164 0 : msg->data = readl(base + PCI_MSIX_ENTRY_DATA);
165 : } else {
166 0 : int pos = dev->msi_cap;
167 : u16 data;
168 :
169 0 : pci_read_config_dword(dev, pos + PCI_MSI_ADDRESS_LO,
170 : &msg->address_lo);
171 0 : if (entry->pci.msi_attrib.is_64) {
172 0 : pci_read_config_dword(dev, pos + PCI_MSI_ADDRESS_HI,
173 : &msg->address_hi);
174 0 : pci_read_config_word(dev, pos + PCI_MSI_DATA_64, &data);
175 : } else {
176 0 : msg->address_hi = 0;
177 0 : pci_read_config_word(dev, pos + PCI_MSI_DATA_32, &data);
178 : }
179 0 : msg->data = data;
180 : }
181 : }
182 :
183 0 : static inline void pci_write_msg_msi(struct pci_dev *dev, struct msi_desc *desc,
184 : struct msi_msg *msg)
185 : {
186 0 : int pos = dev->msi_cap;
187 : u16 msgctl;
188 :
189 0 : pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl);
190 0 : msgctl &= ~PCI_MSI_FLAGS_QSIZE;
191 0 : msgctl |= desc->pci.msi_attrib.multiple << 4;
192 0 : pci_write_config_word(dev, pos + PCI_MSI_FLAGS, msgctl);
193 :
194 0 : pci_write_config_dword(dev, pos + PCI_MSI_ADDRESS_LO, msg->address_lo);
195 0 : if (desc->pci.msi_attrib.is_64) {
196 0 : pci_write_config_dword(dev, pos + PCI_MSI_ADDRESS_HI, msg->address_hi);
197 0 : pci_write_config_word(dev, pos + PCI_MSI_DATA_64, msg->data);
198 : } else {
199 0 : pci_write_config_word(dev, pos + PCI_MSI_DATA_32, msg->data);
200 : }
201 : /* Ensure that the writes are visible in the device */
202 0 : pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl);
203 0 : }
204 :
205 0 : static inline void pci_write_msg_msix(struct msi_desc *desc, struct msi_msg *msg)
206 : {
207 0 : void __iomem *base = pci_msix_desc_addr(desc);
208 0 : u32 ctrl = desc->pci.msix_ctrl;
209 0 : bool unmasked = !(ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT);
210 :
211 0 : if (desc->pci.msi_attrib.is_virtual)
212 : return;
213 : /*
214 : * The specification mandates that the entry is masked
215 : * when the message is modified:
216 : *
217 : * "If software changes the Address or Data value of an
218 : * entry while the entry is unmasked, the result is
219 : * undefined."
220 : */
221 0 : if (unmasked)
222 0 : pci_msix_write_vector_ctrl(desc, ctrl | PCI_MSIX_ENTRY_CTRL_MASKBIT);
223 :
224 0 : writel(msg->address_lo, base + PCI_MSIX_ENTRY_LOWER_ADDR);
225 0 : writel(msg->address_hi, base + PCI_MSIX_ENTRY_UPPER_ADDR);
226 0 : writel(msg->data, base + PCI_MSIX_ENTRY_DATA);
227 :
228 0 : if (unmasked)
229 0 : pci_msix_write_vector_ctrl(desc, ctrl);
230 :
231 : /* Ensure that the writes are visible in the device */
232 0 : readl(base + PCI_MSIX_ENTRY_DATA);
233 : }
234 :
235 0 : void __pci_write_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
236 : {
237 0 : struct pci_dev *dev = msi_desc_to_pci_dev(entry);
238 :
239 0 : if (dev->current_state != PCI_D0 || pci_dev_is_disconnected(dev)) {
240 : /* Don't touch the hardware now */
241 0 : } else if (entry->pci.msi_attrib.is_msix) {
242 0 : pci_write_msg_msix(entry, msg);
243 : } else {
244 0 : pci_write_msg_msi(dev, entry, msg);
245 : }
246 :
247 0 : entry->msg = *msg;
248 :
249 0 : if (entry->write_msi_msg)
250 0 : entry->write_msi_msg(entry, entry->write_msi_msg_data);
251 0 : }
252 :
253 0 : void pci_write_msi_msg(unsigned int irq, struct msi_msg *msg)
254 : {
255 0 : struct msi_desc *entry = irq_get_msi_desc(irq);
256 :
257 0 : __pci_write_msi_msg(entry, msg);
258 0 : }
259 : EXPORT_SYMBOL_GPL(pci_write_msi_msg);
260 :
261 :
262 : /* PCI/MSI specific functionality */
263 :
264 : static void pci_intx_for_msi(struct pci_dev *dev, int enable)
265 : {
266 0 : if (!(dev->dev_flags & PCI_DEV_FLAGS_MSI_INTX_DISABLE_BUG))
267 0 : pci_intx(dev, enable);
268 : }
269 :
270 0 : static void pci_msi_set_enable(struct pci_dev *dev, int enable)
271 : {
272 : u16 control;
273 :
274 0 : pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
275 0 : control &= ~PCI_MSI_FLAGS_ENABLE;
276 0 : if (enable)
277 0 : control |= PCI_MSI_FLAGS_ENABLE;
278 0 : pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, control);
279 0 : }
280 :
281 0 : static int msi_setup_msi_desc(struct pci_dev *dev, int nvec,
282 : struct irq_affinity_desc *masks)
283 : {
284 : struct msi_desc desc;
285 : u16 control;
286 :
287 : /* MSI Entry Initialization */
288 0 : memset(&desc, 0, sizeof(desc));
289 :
290 0 : pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
291 : /* Lies, damned lies, and MSIs */
292 0 : if (dev->dev_flags & PCI_DEV_FLAGS_HAS_MSI_MASKING)
293 0 : control |= PCI_MSI_FLAGS_MASKBIT;
294 : /* Respect XEN's mask disabling */
295 0 : if (pci_msi_ignore_mask)
296 0 : control &= ~PCI_MSI_FLAGS_MASKBIT;
297 :
298 0 : desc.nvec_used = nvec;
299 0 : desc.pci.msi_attrib.is_64 = !!(control & PCI_MSI_FLAGS_64BIT);
300 0 : desc.pci.msi_attrib.can_mask = !!(control & PCI_MSI_FLAGS_MASKBIT);
301 0 : desc.pci.msi_attrib.default_irq = dev->irq;
302 0 : desc.pci.msi_attrib.multi_cap = (control & PCI_MSI_FLAGS_QMASK) >> 1;
303 0 : desc.pci.msi_attrib.multiple = ilog2(__roundup_pow_of_two(nvec));
304 0 : desc.affinity = masks;
305 :
306 0 : if (control & PCI_MSI_FLAGS_64BIT)
307 0 : desc.pci.mask_pos = dev->msi_cap + PCI_MSI_MASK_64;
308 : else
309 0 : desc.pci.mask_pos = dev->msi_cap + PCI_MSI_MASK_32;
310 :
311 : /* Save the initial mask status */
312 0 : if (desc.pci.msi_attrib.can_mask)
313 0 : pci_read_config_dword(dev, desc.pci.mask_pos, &desc.pci.msi_mask);
314 :
315 0 : return msi_insert_msi_desc(&dev->dev, &desc);
316 : }
317 :
318 0 : static int msi_verify_entries(struct pci_dev *dev)
319 : {
320 : struct msi_desc *entry;
321 :
322 0 : if (!dev->no_64bit_msi)
323 : return 0;
324 :
325 0 : msi_for_each_desc(entry, &dev->dev, MSI_DESC_ALL) {
326 0 : if (entry->msg.address_hi) {
327 0 : pci_err(dev, "arch assigned 64-bit MSI address %#x%08x but device only supports 32 bits\n",
328 : entry->msg.address_hi, entry->msg.address_lo);
329 0 : break;
330 : }
331 : }
332 0 : return !entry ? 0 : -EIO;
333 : }
334 :
335 : /**
336 : * msi_capability_init - configure device's MSI capability structure
337 : * @dev: pointer to the pci_dev data structure of MSI device function
338 : * @nvec: number of interrupts to allocate
339 : * @affd: description of automatic IRQ affinity assignments (may be %NULL)
340 : *
341 : * Setup the MSI capability structure of the device with the requested
342 : * number of interrupts. A return value of zero indicates the successful
343 : * setup of an entry with the new MSI IRQ. A negative return value indicates
344 : * an error, and a positive return value indicates the number of interrupts
345 : * which could have been allocated.
346 : */
347 0 : static int msi_capability_init(struct pci_dev *dev, int nvec,
348 : struct irq_affinity *affd)
349 : {
350 0 : struct irq_affinity_desc *masks = NULL;
351 : struct msi_desc *entry;
352 : int ret;
353 :
354 : /* Reject multi-MSI early on irq domain enabled architectures */
355 0 : if (nvec > 1 && !pci_msi_domain_supports(dev, MSI_FLAG_MULTI_PCI_MSI, ALLOW_LEGACY))
356 : return 1;
357 :
358 : /*
359 : * Disable MSI during setup in the hardware, but mark it enabled
360 : * so that setup code can evaluate it.
361 : */
362 0 : pci_msi_set_enable(dev, 0);
363 0 : dev->msi_enabled = 1;
364 :
365 : if (affd)
366 : masks = irq_create_affinity_masks(nvec, affd);
367 :
368 0 : msi_lock_descs(&dev->dev);
369 0 : ret = msi_setup_msi_desc(dev, nvec, masks);
370 0 : if (ret)
371 : goto fail;
372 :
373 : /* All MSIs are unmasked by default; mask them all */
374 0 : entry = msi_first_desc(&dev->dev, MSI_DESC_ALL);
375 0 : pci_msi_mask(entry, msi_multi_mask(entry));
376 :
377 : /* Configure MSI capability structure */
378 0 : ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSI);
379 0 : if (ret)
380 : goto err;
381 :
382 0 : ret = msi_verify_entries(dev);
383 0 : if (ret)
384 : goto err;
385 :
386 : /* Set MSI enabled bits */
387 0 : pci_intx_for_msi(dev, 0);
388 0 : pci_msi_set_enable(dev, 1);
389 :
390 0 : pcibios_free_irq(dev);
391 0 : dev->irq = entry->irq;
392 : goto unlock;
393 :
394 : err:
395 0 : pci_msi_unmask(entry, msi_multi_mask(entry));
396 0 : pci_free_msi_irqs(dev);
397 : fail:
398 0 : dev->msi_enabled = 0;
399 : unlock:
400 0 : msi_unlock_descs(&dev->dev);
401 0 : kfree(masks);
402 : return ret;
403 : }
404 :
405 0 : int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
406 : struct irq_affinity *affd)
407 : {
408 : int nvec;
409 : int rc;
410 :
411 0 : if (!pci_msi_supported(dev, minvec) || dev->current_state != PCI_D0)
412 : return -EINVAL;
413 :
414 : /* Check whether driver already requested MSI-X IRQs */
415 0 : if (dev->msix_enabled) {
416 0 : pci_info(dev, "can't enable MSI (MSI-X already enabled)\n");
417 0 : return -EINVAL;
418 : }
419 :
420 0 : if (maxvec < minvec)
421 : return -ERANGE;
422 :
423 0 : if (WARN_ON_ONCE(dev->msi_enabled))
424 : return -EINVAL;
425 :
426 0 : nvec = pci_msi_vec_count(dev);
427 0 : if (nvec < 0)
428 : return nvec;
429 0 : if (nvec < minvec)
430 : return -ENOSPC;
431 :
432 0 : if (nvec > maxvec)
433 0 : nvec = maxvec;
434 :
435 0 : rc = pci_setup_msi_context(dev);
436 0 : if (rc)
437 : return rc;
438 :
439 0 : if (!pci_setup_msi_device_domain(dev))
440 : return -ENODEV;
441 :
442 : for (;;) {
443 0 : if (affd) {
444 0 : nvec = irq_calc_affinity_vectors(minvec, nvec, affd);
445 0 : if (nvec < minvec)
446 : return -ENOSPC;
447 : }
448 :
449 0 : rc = msi_capability_init(dev, nvec, affd);
450 0 : if (rc == 0)
451 : return nvec;
452 :
453 0 : if (rc < 0)
454 : return rc;
455 0 : if (rc < minvec)
456 : return -ENOSPC;
457 :
458 : nvec = rc;
459 : }
460 : }
461 :
462 : /**
463 : * pci_msi_vec_count - Return the number of MSI vectors a device can send
464 : * @dev: device to report about
465 : *
466 : * This function returns the number of MSI vectors a device requested via
467 : * Multiple Message Capable register. It returns a negative errno if the
468 : * device is not capable sending MSI interrupts. Otherwise, the call succeeds
469 : * and returns a power of two, up to a maximum of 2^5 (32), according to the
470 : * MSI specification.
471 : **/
472 0 : int pci_msi_vec_count(struct pci_dev *dev)
473 : {
474 : int ret;
475 : u16 msgctl;
476 :
477 0 : if (!dev->msi_cap)
478 : return -EINVAL;
479 :
480 0 : pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &msgctl);
481 0 : ret = 1 << ((msgctl & PCI_MSI_FLAGS_QMASK) >> 1);
482 :
483 0 : return ret;
484 : }
485 : EXPORT_SYMBOL(pci_msi_vec_count);
486 :
487 : /*
488 : * Architecture override returns true when the PCI MSI message should be
489 : * written by the generic restore function.
490 : */
491 0 : bool __weak arch_restore_msi_irqs(struct pci_dev *dev)
492 : {
493 0 : return true;
494 : }
495 :
496 0 : void __pci_restore_msi_state(struct pci_dev *dev)
497 : {
498 : struct msi_desc *entry;
499 : u16 control;
500 :
501 0 : if (!dev->msi_enabled)
502 0 : return;
503 :
504 0 : entry = irq_get_msi_desc(dev->irq);
505 :
506 0 : pci_intx_for_msi(dev, 0);
507 0 : pci_msi_set_enable(dev, 0);
508 0 : if (arch_restore_msi_irqs(dev))
509 0 : __pci_write_msi_msg(entry, &entry->msg);
510 :
511 0 : pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
512 0 : pci_msi_update_mask(entry, 0, 0);
513 0 : control &= ~PCI_MSI_FLAGS_QSIZE;
514 0 : control |= (entry->pci.msi_attrib.multiple << 4) | PCI_MSI_FLAGS_ENABLE;
515 0 : pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, control);
516 : }
517 :
518 0 : void pci_msi_shutdown(struct pci_dev *dev)
519 : {
520 : struct msi_desc *desc;
521 :
522 0 : if (!pci_msi_enable || !dev || !dev->msi_enabled)
523 : return;
524 :
525 0 : pci_msi_set_enable(dev, 0);
526 0 : pci_intx_for_msi(dev, 1);
527 0 : dev->msi_enabled = 0;
528 :
529 : /* Return the device with MSI unmasked as initial states */
530 0 : desc = msi_first_desc(&dev->dev, MSI_DESC_ALL);
531 0 : if (!WARN_ON_ONCE(!desc))
532 0 : pci_msi_unmask(desc, msi_multi_mask(desc));
533 :
534 : /* Restore dev->irq to its default pin-assertion IRQ */
535 0 : dev->irq = desc->pci.msi_attrib.default_irq;
536 0 : pcibios_alloc_irq(dev);
537 : }
538 :
539 : /* PCI/MSI-X specific functionality */
540 :
541 0 : static void pci_msix_clear_and_set_ctrl(struct pci_dev *dev, u16 clear, u16 set)
542 : {
543 : u16 ctrl;
544 :
545 0 : pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &ctrl);
546 0 : ctrl &= ~clear;
547 0 : ctrl |= set;
548 0 : pci_write_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, ctrl);
549 0 : }
550 :
551 0 : static void __iomem *msix_map_region(struct pci_dev *dev,
552 : unsigned int nr_entries)
553 : {
554 : resource_size_t phys_addr;
555 : u32 table_offset;
556 : unsigned long flags;
557 : u8 bir;
558 :
559 0 : pci_read_config_dword(dev, dev->msix_cap + PCI_MSIX_TABLE,
560 : &table_offset);
561 0 : bir = (u8)(table_offset & PCI_MSIX_TABLE_BIR);
562 0 : flags = pci_resource_flags(dev, bir);
563 0 : if (!flags || (flags & IORESOURCE_UNSET))
564 : return NULL;
565 :
566 0 : table_offset &= PCI_MSIX_TABLE_OFFSET;
567 0 : phys_addr = pci_resource_start(dev, bir) + table_offset;
568 :
569 0 : return ioremap(phys_addr, nr_entries * PCI_MSIX_ENTRY_SIZE);
570 : }
571 :
572 : /**
573 : * msix_prepare_msi_desc - Prepare a half initialized MSI descriptor for operation
574 : * @dev: The PCI device for which the descriptor is prepared
575 : * @desc: The MSI descriptor for preparation
576 : *
577 : * This is separate from msix_setup_msi_descs() below to handle dynamic
578 : * allocations for MSI-X after initial enablement.
579 : *
580 : * Ideally the whole MSI-X setup would work that way, but there is no way to
581 : * support this for the legacy arch_setup_msi_irqs() mechanism and for the
582 : * fake irq domains like the x86 XEN one. Sigh...
583 : *
584 : * The descriptor is zeroed and only @desc::msi_index and @desc::affinity
585 : * are set. When called from msix_setup_msi_descs() then the is_virtual
586 : * attribute is initialized as well.
587 : *
588 : * Fill in the rest.
589 : */
590 0 : void msix_prepare_msi_desc(struct pci_dev *dev, struct msi_desc *desc)
591 : {
592 0 : desc->nvec_used = 1;
593 0 : desc->pci.msi_attrib.is_msix = 1;
594 0 : desc->pci.msi_attrib.is_64 = 1;
595 0 : desc->pci.msi_attrib.default_irq = dev->irq;
596 0 : desc->pci.mask_base = dev->msix_base;
597 0 : desc->pci.msi_attrib.can_mask = !pci_msi_ignore_mask &&
598 0 : !desc->pci.msi_attrib.is_virtual;
599 :
600 0 : if (desc->pci.msi_attrib.can_mask) {
601 0 : void __iomem *addr = pci_msix_desc_addr(desc);
602 :
603 0 : desc->pci.msix_ctrl = readl(addr + PCI_MSIX_ENTRY_VECTOR_CTRL);
604 : }
605 0 : }
606 :
607 0 : static int msix_setup_msi_descs(struct pci_dev *dev, struct msix_entry *entries,
608 : int nvec, struct irq_affinity_desc *masks)
609 : {
610 0 : int ret = 0, i, vec_count = pci_msix_vec_count(dev);
611 : struct irq_affinity_desc *curmsk;
612 : struct msi_desc desc;
613 :
614 0 : memset(&desc, 0, sizeof(desc));
615 :
616 0 : for (i = 0, curmsk = masks; i < nvec; i++, curmsk++) {
617 0 : desc.msi_index = entries ? entries[i].entry : i;
618 0 : desc.affinity = masks ? curmsk : NULL;
619 0 : desc.pci.msi_attrib.is_virtual = desc.msi_index >= vec_count;
620 :
621 0 : msix_prepare_msi_desc(dev, &desc);
622 :
623 0 : ret = msi_insert_msi_desc(&dev->dev, &desc);
624 0 : if (ret)
625 : break;
626 : }
627 0 : return ret;
628 : }
629 :
630 0 : static void msix_update_entries(struct pci_dev *dev, struct msix_entry *entries)
631 : {
632 : struct msi_desc *desc;
633 :
634 0 : if (entries) {
635 0 : msi_for_each_desc(desc, &dev->dev, MSI_DESC_ALL) {
636 0 : entries->vector = desc->irq;
637 0 : entries++;
638 : }
639 : }
640 0 : }
641 :
642 0 : static void msix_mask_all(void __iomem *base, int tsize)
643 : {
644 0 : u32 ctrl = PCI_MSIX_ENTRY_CTRL_MASKBIT;
645 : int i;
646 :
647 0 : if (pci_msi_ignore_mask)
648 : return;
649 :
650 0 : for (i = 0; i < tsize; i++, base += PCI_MSIX_ENTRY_SIZE)
651 0 : writel(ctrl, base + PCI_MSIX_ENTRY_VECTOR_CTRL);
652 : }
653 :
654 0 : static int msix_setup_interrupts(struct pci_dev *dev, struct msix_entry *entries,
655 : int nvec, struct irq_affinity *affd)
656 : {
657 0 : struct irq_affinity_desc *masks = NULL;
658 : int ret;
659 :
660 : if (affd)
661 : masks = irq_create_affinity_masks(nvec, affd);
662 :
663 0 : msi_lock_descs(&dev->dev);
664 0 : ret = msix_setup_msi_descs(dev, entries, nvec, masks);
665 0 : if (ret)
666 : goto out_free;
667 :
668 0 : ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSIX);
669 0 : if (ret)
670 : goto out_free;
671 :
672 : /* Check if all MSI entries honor device restrictions */
673 0 : ret = msi_verify_entries(dev);
674 0 : if (ret)
675 : goto out_free;
676 :
677 0 : msix_update_entries(dev, entries);
678 : goto out_unlock;
679 :
680 : out_free:
681 0 : pci_free_msi_irqs(dev);
682 : out_unlock:
683 0 : msi_unlock_descs(&dev->dev);
684 0 : kfree(masks);
685 0 : return ret;
686 : }
687 :
688 : /**
689 : * msix_capability_init - configure device's MSI-X capability
690 : * @dev: pointer to the pci_dev data structure of MSI-X device function
691 : * @entries: pointer to an array of struct msix_entry entries
692 : * @nvec: number of @entries
693 : * @affd: Optional pointer to enable automatic affinity assignment
694 : *
695 : * Setup the MSI-X capability structure of device function with a
696 : * single MSI-X IRQ. A return of zero indicates the successful setup of
697 : * requested MSI-X entries with allocated IRQs or non-zero for otherwise.
698 : **/
699 0 : static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries,
700 : int nvec, struct irq_affinity *affd)
701 : {
702 : int ret, tsize;
703 : u16 control;
704 :
705 : /*
706 : * Some devices require MSI-X to be enabled before the MSI-X
707 : * registers can be accessed. Mask all the vectors to prevent
708 : * interrupts coming in before they're fully set up.
709 : */
710 0 : pci_msix_clear_and_set_ctrl(dev, 0, PCI_MSIX_FLAGS_MASKALL |
711 : PCI_MSIX_FLAGS_ENABLE);
712 :
713 : /* Mark it enabled so setup functions can query it */
714 0 : dev->msix_enabled = 1;
715 :
716 0 : pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &control);
717 : /* Request & Map MSI-X table region */
718 0 : tsize = msix_table_size(control);
719 0 : dev->msix_base = msix_map_region(dev, tsize);
720 0 : if (!dev->msix_base) {
721 : ret = -ENOMEM;
722 : goto out_disable;
723 : }
724 :
725 0 : ret = msix_setup_interrupts(dev, entries, nvec, affd);
726 0 : if (ret)
727 : goto out_disable;
728 :
729 : /* Disable INTX */
730 0 : pci_intx_for_msi(dev, 0);
731 :
732 : /*
733 : * Ensure that all table entries are masked to prevent
734 : * stale entries from firing in a crash kernel.
735 : *
736 : * Done late to deal with a broken Marvell NVME device
737 : * which takes the MSI-X mask bits into account even
738 : * when MSI-X is disabled, which prevents MSI delivery.
739 : */
740 0 : msix_mask_all(dev->msix_base, tsize);
741 0 : pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL, 0);
742 :
743 0 : pcibios_free_irq(dev);
744 : return 0;
745 :
746 : out_disable:
747 0 : dev->msix_enabled = 0;
748 0 : pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL | PCI_MSIX_FLAGS_ENABLE, 0);
749 :
750 : return ret;
751 : }
752 :
753 0 : static bool pci_msix_validate_entries(struct pci_dev *dev, struct msix_entry *entries, int nvec)
754 : {
755 : bool nogap;
756 : int i, j;
757 :
758 0 : if (!entries)
759 : return true;
760 :
761 0 : nogap = pci_msi_domain_supports(dev, MSI_FLAG_MSIX_CONTIGUOUS, DENY_LEGACY);
762 :
763 0 : for (i = 0; i < nvec; i++) {
764 : /* Check for duplicate entries */
765 0 : for (j = i + 1; j < nvec; j++) {
766 0 : if (entries[i].entry == entries[j].entry)
767 : return false;
768 : }
769 : /* Check for unsupported gaps */
770 0 : if (nogap && entries[i].entry != i)
771 : return false;
772 : }
773 : return true;
774 : }
775 :
776 0 : int __pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries, int minvec,
777 : int maxvec, struct irq_affinity *affd, int flags)
778 : {
779 0 : int hwsize, rc, nvec = maxvec;
780 :
781 0 : if (maxvec < minvec)
782 : return -ERANGE;
783 :
784 0 : if (dev->msi_enabled) {
785 0 : pci_info(dev, "can't enable MSI-X (MSI already enabled)\n");
786 0 : return -EINVAL;
787 : }
788 :
789 0 : if (WARN_ON_ONCE(dev->msix_enabled))
790 : return -EINVAL;
791 :
792 : /* Check MSI-X early on irq domain enabled architectures */
793 0 : if (!pci_msi_domain_supports(dev, MSI_FLAG_PCI_MSIX, ALLOW_LEGACY))
794 : return -ENOTSUPP;
795 :
796 0 : if (!pci_msi_supported(dev, nvec) || dev->current_state != PCI_D0)
797 : return -EINVAL;
798 :
799 0 : hwsize = pci_msix_vec_count(dev);
800 0 : if (hwsize < 0)
801 : return hwsize;
802 :
803 0 : if (!pci_msix_validate_entries(dev, entries, nvec))
804 : return -EINVAL;
805 :
806 0 : if (hwsize < nvec) {
807 : /* Keep the IRQ virtual hackery working */
808 0 : if (flags & PCI_IRQ_VIRTUAL)
809 : hwsize = nvec;
810 : else
811 0 : nvec = hwsize;
812 : }
813 :
814 0 : if (nvec < minvec)
815 : return -ENOSPC;
816 :
817 0 : rc = pci_setup_msi_context(dev);
818 0 : if (rc)
819 : return rc;
820 :
821 0 : if (!pci_setup_msix_device_domain(dev, hwsize))
822 : return -ENODEV;
823 :
824 : for (;;) {
825 0 : if (affd) {
826 0 : nvec = irq_calc_affinity_vectors(minvec, nvec, affd);
827 0 : if (nvec < minvec)
828 : return -ENOSPC;
829 : }
830 :
831 0 : rc = msix_capability_init(dev, entries, nvec, affd);
832 0 : if (rc == 0)
833 : return nvec;
834 :
835 0 : if (rc < 0)
836 : return rc;
837 0 : if (rc < minvec)
838 : return -ENOSPC;
839 :
840 : nvec = rc;
841 : }
842 : }
843 :
844 0 : void __pci_restore_msix_state(struct pci_dev *dev)
845 : {
846 : struct msi_desc *entry;
847 : bool write_msg;
848 :
849 0 : if (!dev->msix_enabled)
850 : return;
851 :
852 : /* route the table */
853 0 : pci_intx_for_msi(dev, 0);
854 0 : pci_msix_clear_and_set_ctrl(dev, 0,
855 : PCI_MSIX_FLAGS_ENABLE | PCI_MSIX_FLAGS_MASKALL);
856 :
857 0 : write_msg = arch_restore_msi_irqs(dev);
858 :
859 0 : msi_lock_descs(&dev->dev);
860 0 : msi_for_each_desc(entry, &dev->dev, MSI_DESC_ALL) {
861 0 : if (write_msg)
862 0 : __pci_write_msi_msg(entry, &entry->msg);
863 0 : pci_msix_write_vector_ctrl(entry, entry->pci.msix_ctrl);
864 : }
865 0 : msi_unlock_descs(&dev->dev);
866 :
867 0 : pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL, 0);
868 : }
869 :
870 0 : void pci_msix_shutdown(struct pci_dev *dev)
871 : {
872 : struct msi_desc *desc;
873 :
874 0 : if (!pci_msi_enable || !dev || !dev->msix_enabled)
875 : return;
876 :
877 0 : if (pci_dev_is_disconnected(dev)) {
878 0 : dev->msix_enabled = 0;
879 0 : return;
880 : }
881 :
882 : /* Return the device with MSI-X masked as initial states */
883 0 : msi_for_each_desc(desc, &dev->dev, MSI_DESC_ALL)
884 0 : pci_msix_mask(desc);
885 :
886 0 : pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0);
887 0 : pci_intx_for_msi(dev, 1);
888 0 : dev->msix_enabled = 0;
889 0 : pcibios_alloc_irq(dev);
890 : }
891 :
892 : /* Common interfaces */
893 :
894 0 : void pci_free_msi_irqs(struct pci_dev *dev)
895 : {
896 0 : pci_msi_teardown_msi_irqs(dev);
897 :
898 0 : if (dev->msix_base) {
899 0 : iounmap(dev->msix_base);
900 0 : dev->msix_base = NULL;
901 : }
902 0 : }
903 :
904 : /* Misc. infrastructure */
905 :
906 0 : struct pci_dev *msi_desc_to_pci_dev(struct msi_desc *desc)
907 : {
908 0 : return to_pci_dev(desc->dev);
909 : }
910 : EXPORT_SYMBOL(msi_desc_to_pci_dev);
911 :
912 0 : void pci_no_msi(void)
913 : {
914 0 : pci_msi_enable = 0;
915 0 : }
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