1 /*
2  * Copyright (c) 2010 - 2017 Intel Corporation.  All rights reserved.
3  * Copyright (c) 2008, 2009 QLogic Corporation. All rights reserved.
4  *
5  * This software is available to you under a choice of one of two
6  * licenses.  You may choose to be licensed under the terms of the GNU
7  * General Public License (GPL) Version 2, available from the file
8  * COPYING in the main directory of this source tree, or the
9  * OpenIB.org BSD license below:
10  *
11  *     Redistribution and use in source and binary forms, with or
12  *     without modification, are permitted provided that the following
13  *     conditions are met:
14  *
15  *      - Redistributions of source code must retain the above
16  *        copyright notice, this list of conditions and the following
17  *        disclaimer.
18  *
19  *      - Redistributions in binary form must reproduce the above
20  *        copyright notice, this list of conditions and the following
21  *        disclaimer in the documentation and/or other materials
22  *        provided with the distribution.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31  * SOFTWARE.
32  */
33 
34 #include <linux/pci.h>
35 #include <linux/io.h>
36 #include <linux/delay.h>
37 #include <linux/vmalloc.h>
38 #include <linux/aer.h>
39 #include <linux/module.h>
40 
41 #include "qib.h"
42 
43 /*
44  * This file contains PCIe utility routines that are common to the
45  * various QLogic InfiniPath adapters
46  */
47 
48 /*
49  * Code to adjust PCIe capabilities.
50  * To minimize the change footprint, we call it
51  * from qib_pcie_params, which every chip-specific
52  * file calls, even though this violates some
53  * expectations of harmlessness.
54  */
55 static void qib_tune_pcie_caps(struct qib_devdata *);
56 static void qib_tune_pcie_coalesce(struct qib_devdata *);
57 
58 /*
59  * Do all the common PCIe setup and initialization.
60  * devdata is not yet allocated, and is not allocated until after this
61  * routine returns success.  Therefore qib_dev_err() can't be used for error
62  * printing.
63  */
64 int qib_pcie_init(struct pci_dev *pdev, const struct pci_device_id *ent)
65 {
66 	int ret;
67 
68 	ret = pci_enable_device(pdev);
69 	if (ret) {
70 		/*
71 		 * This can happen (in theory) iff:
72 		 * We did a chip reset, and then failed to reprogram the
73 		 * BAR, or the chip reset due to an internal error.  We then
74 		 * unloaded the driver and reloaded it.
75 		 *
76 		 * Both reset cases set the BAR back to initial state.  For
77 		 * the latter case, the AER sticky error bit at offset 0x718
78 		 * should be set, but the Linux kernel doesn't yet know
79 		 * about that, it appears.  If the original BAR was retained
80 		 * in the kernel data structures, this may be OK.
81 		 */
82 		qib_early_err(&pdev->dev, "pci enable failed: error %d\n",
83 			      -ret);
84 		goto done;
85 	}
86 
87 	ret = pci_request_regions(pdev, QIB_DRV_NAME);
88 	if (ret) {
89 		qib_devinfo(pdev, "pci_request_regions fails: err %d\n", -ret);
90 		goto bail;
91 	}
92 
93 	ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(64));
94 	if (ret) {
95 		/*
96 		 * If the 64 bit setup fails, try 32 bit.  Some systems
97 		 * do not setup 64 bit maps on systems with 2GB or less
98 		 * memory installed.
99 		 */
100 		ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
101 		if (ret) {
102 			qib_devinfo(pdev, "Unable to set DMA mask: %d\n", ret);
103 			goto bail;
104 		}
105 		ret = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32));
106 	} else
107 		ret = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64));
108 	if (ret) {
109 		qib_early_err(&pdev->dev,
110 			      "Unable to set DMA consistent mask: %d\n", ret);
111 		goto bail;
112 	}
113 
114 	pci_set_master(pdev);
115 	ret = pci_enable_pcie_error_reporting(pdev);
116 	if (ret) {
117 		qib_early_err(&pdev->dev,
118 			      "Unable to enable pcie error reporting: %d\n",
119 			      ret);
120 		ret = 0;
121 	}
122 	goto done;
123 
124 bail:
125 	pci_disable_device(pdev);
126 	pci_release_regions(pdev);
127 done:
128 	return ret;
129 }
130 
131 /*
132  * Do remaining PCIe setup, once dd is allocated, and save away
133  * fields required to re-initialize after a chip reset, or for
134  * various other purposes
135  */
136 int qib_pcie_ddinit(struct qib_devdata *dd, struct pci_dev *pdev,
137 		    const struct pci_device_id *ent)
138 {
139 	unsigned long len;
140 	resource_size_t addr;
141 
142 	dd->pcidev = pdev;
143 	pci_set_drvdata(pdev, dd);
144 
145 	addr = pci_resource_start(pdev, 0);
146 	len = pci_resource_len(pdev, 0);
147 
148 	dd->kregbase = ioremap_nocache(addr, len);
149 	if (!dd->kregbase)
150 		return -ENOMEM;
151 
152 	dd->kregend = (u64 __iomem *)((void __iomem *) dd->kregbase + len);
153 	dd->physaddr = addr;        /* used for io_remap, etc. */
154 
155 	/*
156 	 * Save BARs to rewrite after device reset.  Save all 64 bits of
157 	 * BAR, just in case.
158 	 */
159 	dd->pcibar0 = addr;
160 	dd->pcibar1 = addr >> 32;
161 	dd->deviceid = ent->device; /* save for later use */
162 	dd->vendorid = ent->vendor;
163 
164 	return 0;
165 }
166 
167 /*
168  * Do PCIe cleanup, after chip-specific cleanup, etc.  Just prior
169  * to releasing the dd memory.
170  * void because none of the core pcie cleanup returns are void
171  */
172 void qib_pcie_ddcleanup(struct qib_devdata *dd)
173 {
174 	u64 __iomem *base = (void __iomem *) dd->kregbase;
175 
176 	dd->kregbase = NULL;
177 	iounmap(base);
178 	if (dd->piobase)
179 		iounmap(dd->piobase);
180 	if (dd->userbase)
181 		iounmap(dd->userbase);
182 	if (dd->piovl15base)
183 		iounmap(dd->piovl15base);
184 
185 	pci_disable_device(dd->pcidev);
186 	pci_release_regions(dd->pcidev);
187 
188 	pci_set_drvdata(dd->pcidev, NULL);
189 }
190 
191 /**
192  * We save the msi lo and hi values, so we can restore them after
193  * chip reset (the kernel PCI infrastructure doesn't yet handle that
194  * correctly.
195  */
196 static void qib_msi_setup(struct qib_devdata *dd, int pos)
197 {
198 	struct pci_dev *pdev = dd->pcidev;
199 	u16 control;
200 
201 	pci_read_config_dword(pdev, pos + PCI_MSI_ADDRESS_LO, &dd->msi_lo);
202 	pci_read_config_dword(pdev, pos + PCI_MSI_ADDRESS_HI, &dd->msi_hi);
203 	pci_read_config_word(pdev, pos + PCI_MSI_FLAGS, &control);
204 
205 	/* now save the data (vector) info */
206 	pci_read_config_word(pdev,
207 			     pos + ((control & PCI_MSI_FLAGS_64BIT) ? 12 : 8),
208 			     &dd->msi_data);
209 }
210 
211 static int qib_allocate_irqs(struct qib_devdata *dd, u32 maxvec)
212 {
213 	unsigned int flags = PCI_IRQ_LEGACY;
214 
215 	/* Check our capabilities */
216 	if (dd->pcidev->msix_cap) {
217 		flags |= PCI_IRQ_MSIX;
218 	} else {
219 		if (dd->pcidev->msi_cap) {
220 			flags |= PCI_IRQ_MSI;
221 			/* Get msi_lo and msi_hi */
222 			qib_msi_setup(dd, dd->pcidev->msi_cap);
223 		}
224 	}
225 
226 	if (!(flags & (PCI_IRQ_MSIX | PCI_IRQ_MSI)))
227 		qib_dev_err(dd, "No PCI MSI or MSIx capability!\n");
228 
229 	return pci_alloc_irq_vectors(dd->pcidev, 1, maxvec, flags);
230 }
231 
232 int qib_pcie_params(struct qib_devdata *dd, u32 minw, u32 *nent)
233 {
234 	u16 linkstat, speed;
235 	int nvec;
236 	int maxvec;
237 	int ret = 0;
238 
239 	if (!pci_is_pcie(dd->pcidev)) {
240 		qib_dev_err(dd, "Can't find PCI Express capability!\n");
241 		/* set up something... */
242 		dd->lbus_width = 1;
243 		dd->lbus_speed = 2500; /* Gen1, 2.5GHz */
244 		ret = -1;
245 		goto bail;
246 	}
247 
248 	maxvec = (nent && *nent) ? *nent : 1;
249 	nvec = qib_allocate_irqs(dd, maxvec);
250 	if (nvec < 0) {
251 		ret = nvec;
252 		goto bail;
253 	}
254 
255 	/*
256 	 * If nent exists, make sure to record how many vectors were allocated
257 	 */
258 	if (nent) {
259 		*nent = nvec;
260 
261 		/*
262 		 * If we requested (nent) MSIX, but msix_enabled is not set,
263 		 * pci_alloc_irq_vectors() enabled INTx.
264 		 */
265 		if (!dd->pcidev->msix_enabled)
266 			qib_dev_err(dd,
267 				    "no msix vectors allocated, using INTx\n");
268 	}
269 
270 	pcie_capability_read_word(dd->pcidev, PCI_EXP_LNKSTA, &linkstat);
271 	/*
272 	 * speed is bits 0-3, linkwidth is bits 4-8
273 	 * no defines for them in headers
274 	 */
275 	speed = linkstat & 0xf;
276 	linkstat >>= 4;
277 	linkstat &= 0x1f;
278 	dd->lbus_width = linkstat;
279 
280 	switch (speed) {
281 	case 1:
282 		dd->lbus_speed = 2500; /* Gen1, 2.5GHz */
283 		break;
284 	case 2:
285 		dd->lbus_speed = 5000; /* Gen1, 5GHz */
286 		break;
287 	default: /* not defined, assume gen1 */
288 		dd->lbus_speed = 2500;
289 		break;
290 	}
291 
292 	/*
293 	 * Check against expected pcie width and complain if "wrong"
294 	 * on first initialization, not afterwards (i.e., reset).
295 	 */
296 	if (minw && linkstat < minw)
297 		qib_dev_err(dd,
298 			    "PCIe width %u (x%u HCA), performance reduced\n",
299 			    linkstat, minw);
300 
301 	qib_tune_pcie_caps(dd);
302 
303 	qib_tune_pcie_coalesce(dd);
304 
305 bail:
306 	/* fill in string, even on errors */
307 	snprintf(dd->lbus_info, sizeof(dd->lbus_info),
308 		 "PCIe,%uMHz,x%u\n", dd->lbus_speed, dd->lbus_width);
309 	return ret;
310 }
311 
312 /*
313  * Setup pcie interrupt stuff again after a reset.  I'd like to just call
314  * pci_enable_msi() again for msi, but when I do that,
315  * the MSI enable bit doesn't get set in the command word, and
316  * we switch to to a different interrupt vector, which is confusing,
317  * so I instead just do it all inline.  Perhaps somehow can tie this
318  * into the PCIe hotplug support at some point
319  */
320 int qib_reinit_intr(struct qib_devdata *dd)
321 {
322 	int pos;
323 	u16 control;
324 	int ret = 0;
325 
326 	/* If we aren't using MSI, don't restore it */
327 	if (!dd->msi_lo)
328 		goto bail;
329 
330 	pos = dd->pcidev->msi_cap;
331 	if (!pos) {
332 		qib_dev_err(dd,
333 			"Can't find MSI capability, can't restore MSI settings\n");
334 		ret = 0;
335 		/* nothing special for MSIx, just MSI */
336 		goto bail;
337 	}
338 	pci_write_config_dword(dd->pcidev, pos + PCI_MSI_ADDRESS_LO,
339 			       dd->msi_lo);
340 	pci_write_config_dword(dd->pcidev, pos + PCI_MSI_ADDRESS_HI,
341 			       dd->msi_hi);
342 	pci_read_config_word(dd->pcidev, pos + PCI_MSI_FLAGS, &control);
343 	if (!(control & PCI_MSI_FLAGS_ENABLE)) {
344 		control |= PCI_MSI_FLAGS_ENABLE;
345 		pci_write_config_word(dd->pcidev, pos + PCI_MSI_FLAGS,
346 				      control);
347 	}
348 	/* now rewrite the data (vector) info */
349 	pci_write_config_word(dd->pcidev, pos +
350 			      ((control & PCI_MSI_FLAGS_64BIT) ? 12 : 8),
351 			      dd->msi_data);
352 	ret = 1;
353 bail:
354 	if (!ret && (dd->flags & QIB_HAS_INTX)) {
355 		qib_enable_intx(dd);
356 		ret = 1;
357 	}
358 
359 	/* and now set the pci master bit again */
360 	pci_set_master(dd->pcidev);
361 
362 	return ret;
363 }
364 
365 /*
366  * Disable msi interrupt if enabled, and clear msi_lo.
367  * This is used primarily for the fallback to INTx, but
368  * is also used in reinit after reset, and during cleanup.
369  */
370 void qib_nomsi(struct qib_devdata *dd)
371 {
372 	dd->msi_lo = 0;
373 	pci_free_irq_vectors(dd->pcidev);
374 }
375 
376 /*
377  * Same as qib_nosmi, but for MSIx.
378  */
379 void qib_nomsix(struct qib_devdata *dd)
380 {
381 	pci_free_irq_vectors(dd->pcidev);
382 }
383 
384 /*
385  * Similar to pci_intx(pdev, 1), except that we make sure
386  * msi(x) is off.
387  */
388 void qib_enable_intx(struct qib_devdata *dd)
389 {
390 	u16 cw, new;
391 	int pos;
392 	struct pci_dev *pdev = dd->pcidev;
393 
394 	if (pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_LEGACY) < 0)
395 		qib_dev_err(dd,	"Failed to enable INTx\n");
396 
397 	pos = pdev->msi_cap;
398 	if (pos) {
399 		/* then turn off MSI */
400 		pci_read_config_word(pdev, pos + PCI_MSI_FLAGS, &cw);
401 		new = cw & ~PCI_MSI_FLAGS_ENABLE;
402 		if (new != cw)
403 			pci_write_config_word(pdev, pos + PCI_MSI_FLAGS, new);
404 	}
405 	pos = pdev->msix_cap;
406 	if (pos) {
407 		/* then turn off MSIx */
408 		pci_read_config_word(pdev, pos + PCI_MSIX_FLAGS, &cw);
409 		new = cw & ~PCI_MSIX_FLAGS_ENABLE;
410 		if (new != cw)
411 			pci_write_config_word(pdev, pos + PCI_MSIX_FLAGS, new);
412 	}
413 }
414 
415 /*
416  * These two routines are helper routines for the device reset code
417  * to move all the pcie code out of the chip-specific driver code.
418  */
419 void qib_pcie_getcmd(struct qib_devdata *dd, u16 *cmd, u8 *iline, u8 *cline)
420 {
421 	pci_read_config_word(dd->pcidev, PCI_COMMAND, cmd);
422 	pci_read_config_byte(dd->pcidev, PCI_INTERRUPT_LINE, iline);
423 	pci_read_config_byte(dd->pcidev, PCI_CACHE_LINE_SIZE, cline);
424 }
425 
426 void qib_pcie_reenable(struct qib_devdata *dd, u16 cmd, u8 iline, u8 cline)
427 {
428 	int r;
429 
430 	r = pci_write_config_dword(dd->pcidev, PCI_BASE_ADDRESS_0,
431 				   dd->pcibar0);
432 	if (r)
433 		qib_dev_err(dd, "rewrite of BAR0 failed: %d\n", r);
434 	r = pci_write_config_dword(dd->pcidev, PCI_BASE_ADDRESS_1,
435 				   dd->pcibar1);
436 	if (r)
437 		qib_dev_err(dd, "rewrite of BAR1 failed: %d\n", r);
438 	/* now re-enable memory access, and restore cosmetic settings */
439 	pci_write_config_word(dd->pcidev, PCI_COMMAND, cmd);
440 	pci_write_config_byte(dd->pcidev, PCI_INTERRUPT_LINE, iline);
441 	pci_write_config_byte(dd->pcidev, PCI_CACHE_LINE_SIZE, cline);
442 	r = pci_enable_device(dd->pcidev);
443 	if (r)
444 		qib_dev_err(dd,
445 			"pci_enable_device failed after reset: %d\n", r);
446 }
447 
448 
449 static int qib_pcie_coalesce;
450 module_param_named(pcie_coalesce, qib_pcie_coalesce, int, S_IRUGO);
451 MODULE_PARM_DESC(pcie_coalesce, "tune PCIe colescing on some Intel chipsets");
452 
453 /*
454  * Enable PCIe completion and data coalescing, on Intel 5x00 and 7300
455  * chipsets.   This is known to be unsafe for some revisions of some
456  * of these chipsets, with some BIOS settings, and enabling it on those
457  * systems may result in the system crashing, and/or data corruption.
458  */
459 static void qib_tune_pcie_coalesce(struct qib_devdata *dd)
460 {
461 	int r;
462 	struct pci_dev *parent;
463 	u16 devid;
464 	u32 mask, bits, val;
465 
466 	if (!qib_pcie_coalesce)
467 		return;
468 
469 	/* Find out supported and configured values for parent (root) */
470 	parent = dd->pcidev->bus->self;
471 	if (parent->bus->parent) {
472 		qib_devinfo(dd->pcidev, "Parent not root\n");
473 		return;
474 	}
475 	if (!pci_is_pcie(parent))
476 		return;
477 	if (parent->vendor != 0x8086)
478 		return;
479 
480 	/*
481 	 *  - bit 12: Max_rdcmp_Imt_EN: need to set to 1
482 	 *  - bit 11: COALESCE_FORCE: need to set to 0
483 	 *  - bit 10: COALESCE_EN: need to set to 1
484 	 *  (but limitations on some on some chipsets)
485 	 *
486 	 *  On the Intel 5000, 5100, and 7300 chipsets, there is
487 	 *  also: - bit 25:24: COALESCE_MODE, need to set to 0
488 	 */
489 	devid = parent->device;
490 	if (devid >= 0x25e2 && devid <= 0x25fa) {
491 		/* 5000 P/V/X/Z */
492 		if (parent->revision <= 0xb2)
493 			bits = 1U << 10;
494 		else
495 			bits = 7U << 10;
496 		mask = (3U << 24) | (7U << 10);
497 	} else if (devid >= 0x65e2 && devid <= 0x65fa) {
498 		/* 5100 */
499 		bits = 1U << 10;
500 		mask = (3U << 24) | (7U << 10);
501 	} else if (devid >= 0x4021 && devid <= 0x402e) {
502 		/* 5400 */
503 		bits = 7U << 10;
504 		mask = 7U << 10;
505 	} else if (devid >= 0x3604 && devid <= 0x360a) {
506 		/* 7300 */
507 		bits = 7U << 10;
508 		mask = (3U << 24) | (7U << 10);
509 	} else {
510 		/* not one of the chipsets that we know about */
511 		return;
512 	}
513 	pci_read_config_dword(parent, 0x48, &val);
514 	val &= ~mask;
515 	val |= bits;
516 	r = pci_write_config_dword(parent, 0x48, val);
517 }
518 
519 /*
520  * BIOS may not set PCIe bus-utilization parameters for best performance.
521  * Check and optionally adjust them to maximize our throughput.
522  */
523 static int qib_pcie_caps;
524 module_param_named(pcie_caps, qib_pcie_caps, int, S_IRUGO);
525 MODULE_PARM_DESC(pcie_caps, "Max PCIe tuning: Payload (0..3), ReadReq (4..7)");
526 
527 static void qib_tune_pcie_caps(struct qib_devdata *dd)
528 {
529 	struct pci_dev *parent;
530 	u16 rc_mpss, rc_mps, ep_mpss, ep_mps;
531 	u16 rc_mrrs, ep_mrrs, max_mrrs;
532 
533 	/* Find out supported and configured values for parent (root) */
534 	parent = dd->pcidev->bus->self;
535 	if (!pci_is_root_bus(parent->bus)) {
536 		qib_devinfo(dd->pcidev, "Parent not root\n");
537 		return;
538 	}
539 
540 	if (!pci_is_pcie(parent) || !pci_is_pcie(dd->pcidev))
541 		return;
542 
543 	rc_mpss = parent->pcie_mpss;
544 	rc_mps = ffs(pcie_get_mps(parent)) - 8;
545 	/* Find out supported and configured values for endpoint (us) */
546 	ep_mpss = dd->pcidev->pcie_mpss;
547 	ep_mps = ffs(pcie_get_mps(dd->pcidev)) - 8;
548 
549 	/* Find max payload supported by root, endpoint */
550 	if (rc_mpss > ep_mpss)
551 		rc_mpss = ep_mpss;
552 
553 	/* If Supported greater than limit in module param, limit it */
554 	if (rc_mpss > (qib_pcie_caps & 7))
555 		rc_mpss = qib_pcie_caps & 7;
556 	/* If less than (allowed, supported), bump root payload */
557 	if (rc_mpss > rc_mps) {
558 		rc_mps = rc_mpss;
559 		pcie_set_mps(parent, 128 << rc_mps);
560 	}
561 	/* If less than (allowed, supported), bump endpoint payload */
562 	if (rc_mpss > ep_mps) {
563 		ep_mps = rc_mpss;
564 		pcie_set_mps(dd->pcidev, 128 << ep_mps);
565 	}
566 
567 	/*
568 	 * Now the Read Request size.
569 	 * No field for max supported, but PCIe spec limits it to 4096,
570 	 * which is code '5' (log2(4096) - 7)
571 	 */
572 	max_mrrs = 5;
573 	if (max_mrrs > ((qib_pcie_caps >> 4) & 7))
574 		max_mrrs = (qib_pcie_caps >> 4) & 7;
575 
576 	max_mrrs = 128 << max_mrrs;
577 	rc_mrrs = pcie_get_readrq(parent);
578 	ep_mrrs = pcie_get_readrq(dd->pcidev);
579 
580 	if (max_mrrs > rc_mrrs) {
581 		rc_mrrs = max_mrrs;
582 		pcie_set_readrq(parent, rc_mrrs);
583 	}
584 	if (max_mrrs > ep_mrrs) {
585 		ep_mrrs = max_mrrs;
586 		pcie_set_readrq(dd->pcidev, ep_mrrs);
587 	}
588 }
589 /* End of PCIe capability tuning */
590 
591 /*
592  * From here through qib_pci_err_handler definition is invoked via
593  * PCI error infrastructure, registered via pci
594  */
595 static pci_ers_result_t
596 qib_pci_error_detected(struct pci_dev *pdev, pci_channel_state_t state)
597 {
598 	struct qib_devdata *dd = pci_get_drvdata(pdev);
599 	pci_ers_result_t ret = PCI_ERS_RESULT_RECOVERED;
600 
601 	switch (state) {
602 	case pci_channel_io_normal:
603 		qib_devinfo(pdev, "State Normal, ignoring\n");
604 		break;
605 
606 	case pci_channel_io_frozen:
607 		qib_devinfo(pdev, "State Frozen, requesting reset\n");
608 		pci_disable_device(pdev);
609 		ret = PCI_ERS_RESULT_NEED_RESET;
610 		break;
611 
612 	case pci_channel_io_perm_failure:
613 		qib_devinfo(pdev, "State Permanent Failure, disabling\n");
614 		if (dd) {
615 			/* no more register accesses! */
616 			dd->flags &= ~QIB_PRESENT;
617 			qib_disable_after_error(dd);
618 		}
619 		 /* else early, or other problem */
620 		ret =  PCI_ERS_RESULT_DISCONNECT;
621 		break;
622 
623 	default: /* shouldn't happen */
624 		qib_devinfo(pdev, "QIB PCI errors detected (state %d)\n",
625 			state);
626 		break;
627 	}
628 	return ret;
629 }
630 
631 static pci_ers_result_t
632 qib_pci_mmio_enabled(struct pci_dev *pdev)
633 {
634 	u64 words = 0U;
635 	struct qib_devdata *dd = pci_get_drvdata(pdev);
636 	pci_ers_result_t ret = PCI_ERS_RESULT_RECOVERED;
637 
638 	if (dd && dd->pport) {
639 		words = dd->f_portcntr(dd->pport, QIBPORTCNTR_WORDRCV);
640 		if (words == ~0ULL)
641 			ret = PCI_ERS_RESULT_NEED_RESET;
642 	}
643 	qib_devinfo(pdev,
644 		"QIB mmio_enabled function called, read wordscntr %Lx, returning %d\n",
645 		words, ret);
646 	return  ret;
647 }
648 
649 static pci_ers_result_t
650 qib_pci_slot_reset(struct pci_dev *pdev)
651 {
652 	qib_devinfo(pdev, "QIB slot_reset function called, ignored\n");
653 	return PCI_ERS_RESULT_CAN_RECOVER;
654 }
655 
656 static void
657 qib_pci_resume(struct pci_dev *pdev)
658 {
659 	struct qib_devdata *dd = pci_get_drvdata(pdev);
660 
661 	qib_devinfo(pdev, "QIB resume function called\n");
662 	pci_cleanup_aer_uncorrect_error_status(pdev);
663 	/*
664 	 * Running jobs will fail, since it's asynchronous
665 	 * unlike sysfs-requested reset.   Better than
666 	 * doing nothing.
667 	 */
668 	qib_init(dd, 1); /* same as re-init after reset */
669 }
670 
671 const struct pci_error_handlers qib_pci_err_handler = {
672 	.error_detected = qib_pci_error_detected,
673 	.mmio_enabled = qib_pci_mmio_enabled,
674 	.slot_reset = qib_pci_slot_reset,
675 	.resume = qib_pci_resume,
676 };
677