1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * The file intends to implement the platform dependent EEH operations on pseries.
4  * Actually, the pseries platform is built based on RTAS heavily. That means the
5  * pseries platform dependent EEH operations will be built on RTAS calls. The functions
6  * are derived from arch/powerpc/platforms/pseries/eeh.c and necessary cleanup has
7  * been done.
8  *
9  * Copyright Benjamin Herrenschmidt & Gavin Shan, IBM Corporation 2011.
10  * Copyright IBM Corporation 2001, 2005, 2006
11  * Copyright Dave Engebretsen & Todd Inglett 2001
12  * Copyright Linas Vepstas 2005, 2006
13  */
14 
15 #include <linux/atomic.h>
16 #include <linux/delay.h>
17 #include <linux/export.h>
18 #include <linux/init.h>
19 #include <linux/list.h>
20 #include <linux/of.h>
21 #include <linux/pci.h>
22 #include <linux/proc_fs.h>
23 #include <linux/rbtree.h>
24 #include <linux/sched.h>
25 #include <linux/seq_file.h>
26 #include <linux/spinlock.h>
27 
28 #include <asm/eeh.h>
29 #include <asm/eeh_event.h>
30 #include <asm/io.h>
31 #include <asm/machdep.h>
32 #include <asm/ppc-pci.h>
33 #include <asm/rtas.h>
34 
35 /* RTAS tokens */
36 static int ibm_set_eeh_option;
37 static int ibm_set_slot_reset;
38 static int ibm_read_slot_reset_state;
39 static int ibm_read_slot_reset_state2;
40 static int ibm_slot_error_detail;
41 static int ibm_get_config_addr_info;
42 static int ibm_get_config_addr_info2;
43 static int ibm_configure_pe;
44 
45 void pseries_pcibios_bus_add_device(struct pci_dev *pdev)
46 {
47 	struct pci_dn *pdn = pci_get_pdn(pdev);
48 
49 	if (eeh_has_flag(EEH_FORCE_DISABLED))
50 		return;
51 
52 	dev_dbg(&pdev->dev, "EEH: Setting up device\n");
53 #ifdef CONFIG_PCI_IOV
54 	if (pdev->is_virtfn) {
55 		struct pci_dn *physfn_pdn;
56 
57 		pdn->device_id  =  pdev->device;
58 		pdn->vendor_id  =  pdev->vendor;
59 		pdn->class_code =  pdev->class;
60 		/*
61 		 * Last allow unfreeze return code used for retrieval
62 		 * by user space in eeh-sysfs to show the last command
63 		 * completion from platform.
64 		 */
65 		pdn->last_allow_rc =  0;
66 		physfn_pdn      =  pci_get_pdn(pdev->physfn);
67 		pdn->pe_number  =  physfn_pdn->pe_num_map[pdn->vf_index];
68 	}
69 #endif
70 	eeh_add_device_early(pdn);
71 	eeh_add_device_late(pdev);
72 #ifdef CONFIG_PCI_IOV
73 	if (pdev->is_virtfn) {
74 		struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
75 
76 		edev->pe_config_addr =  (pdn->busno << 16) | (pdn->devfn << 8);
77 		eeh_rmv_from_parent_pe(edev); /* Remove as it is adding to bus pe */
78 		eeh_add_to_parent_pe(edev);   /* Add as VF PE type */
79 	}
80 #endif
81 	eeh_sysfs_add_device(pdev);
82 }
83 
84 /*
85  * Buffer for reporting slot-error-detail rtas calls. Its here
86  * in BSS, and not dynamically alloced, so that it ends up in
87  * RMO where RTAS can access it.
88  */
89 static unsigned char slot_errbuf[RTAS_ERROR_LOG_MAX];
90 static DEFINE_SPINLOCK(slot_errbuf_lock);
91 static int eeh_error_buf_size;
92 
93 /**
94  * pseries_eeh_init - EEH platform dependent initialization
95  *
96  * EEH platform dependent initialization on pseries.
97  */
98 static int pseries_eeh_init(void)
99 {
100 	/* figure out EEH RTAS function call tokens */
101 	ibm_set_eeh_option		= rtas_token("ibm,set-eeh-option");
102 	ibm_set_slot_reset		= rtas_token("ibm,set-slot-reset");
103 	ibm_read_slot_reset_state2	= rtas_token("ibm,read-slot-reset-state2");
104 	ibm_read_slot_reset_state	= rtas_token("ibm,read-slot-reset-state");
105 	ibm_slot_error_detail		= rtas_token("ibm,slot-error-detail");
106 	ibm_get_config_addr_info2	= rtas_token("ibm,get-config-addr-info2");
107 	ibm_get_config_addr_info	= rtas_token("ibm,get-config-addr-info");
108 	ibm_configure_pe		= rtas_token("ibm,configure-pe");
109 
110 	/*
111 	 * ibm,configure-pe and ibm,configure-bridge have the same semantics,
112 	 * however ibm,configure-pe can be faster.  If we can't find
113 	 * ibm,configure-pe then fall back to using ibm,configure-bridge.
114 	 */
115 	if (ibm_configure_pe == RTAS_UNKNOWN_SERVICE)
116 		ibm_configure_pe 	= rtas_token("ibm,configure-bridge");
117 
118 	/*
119 	 * Necessary sanity check. We needn't check "get-config-addr-info"
120 	 * and its variant since the old firmware probably support address
121 	 * of domain/bus/slot/function for EEH RTAS operations.
122 	 */
123 	if (ibm_set_eeh_option == RTAS_UNKNOWN_SERVICE		||
124 	    ibm_set_slot_reset == RTAS_UNKNOWN_SERVICE		||
125 	    (ibm_read_slot_reset_state2 == RTAS_UNKNOWN_SERVICE &&
126 	     ibm_read_slot_reset_state == RTAS_UNKNOWN_SERVICE)	||
127 	    ibm_slot_error_detail == RTAS_UNKNOWN_SERVICE	||
128 	    ibm_configure_pe == RTAS_UNKNOWN_SERVICE) {
129 		pr_info("EEH functionality not supported\n");
130 		return -EINVAL;
131 	}
132 
133 	/* Initialize error log lock and size */
134 	spin_lock_init(&slot_errbuf_lock);
135 	eeh_error_buf_size = rtas_token("rtas-error-log-max");
136 	if (eeh_error_buf_size == RTAS_UNKNOWN_SERVICE) {
137 		pr_info("%s: unknown EEH error log size\n",
138 			__func__);
139 		eeh_error_buf_size = 1024;
140 	} else if (eeh_error_buf_size > RTAS_ERROR_LOG_MAX) {
141 		pr_info("%s: EEH error log size %d exceeds the maximal %d\n",
142 			__func__, eeh_error_buf_size, RTAS_ERROR_LOG_MAX);
143 		eeh_error_buf_size = RTAS_ERROR_LOG_MAX;
144 	}
145 
146 	/* Set EEH probe mode */
147 	eeh_add_flag(EEH_PROBE_MODE_DEVTREE | EEH_ENABLE_IO_FOR_LOG);
148 
149 	/* Set EEH machine dependent code */
150 	ppc_md.pcibios_bus_add_device = pseries_pcibios_bus_add_device;
151 
152 	return 0;
153 }
154 
155 static int pseries_eeh_cap_start(struct pci_dn *pdn)
156 {
157 	u32 status;
158 
159 	if (!pdn)
160 		return 0;
161 
162 	rtas_read_config(pdn, PCI_STATUS, 2, &status);
163 	if (!(status & PCI_STATUS_CAP_LIST))
164 		return 0;
165 
166 	return PCI_CAPABILITY_LIST;
167 }
168 
169 
170 static int pseries_eeh_find_cap(struct pci_dn *pdn, int cap)
171 {
172 	int pos = pseries_eeh_cap_start(pdn);
173 	int cnt = 48;	/* Maximal number of capabilities */
174 	u32 id;
175 
176 	if (!pos)
177 		return 0;
178 
179         while (cnt--) {
180 		rtas_read_config(pdn, pos, 1, &pos);
181 		if (pos < 0x40)
182 			break;
183 		pos &= ~3;
184 		rtas_read_config(pdn, pos + PCI_CAP_LIST_ID, 1, &id);
185 		if (id == 0xff)
186 			break;
187 		if (id == cap)
188 			return pos;
189 		pos += PCI_CAP_LIST_NEXT;
190 	}
191 
192 	return 0;
193 }
194 
195 static int pseries_eeh_find_ecap(struct pci_dn *pdn, int cap)
196 {
197 	struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
198 	u32 header;
199 	int pos = 256;
200 	int ttl = (4096 - 256) / 8;
201 
202 	if (!edev || !edev->pcie_cap)
203 		return 0;
204 	if (rtas_read_config(pdn, pos, 4, &header) != PCIBIOS_SUCCESSFUL)
205 		return 0;
206 	else if (!header)
207 		return 0;
208 
209 	while (ttl-- > 0) {
210 		if (PCI_EXT_CAP_ID(header) == cap && pos)
211 			return pos;
212 
213 		pos = PCI_EXT_CAP_NEXT(header);
214 		if (pos < 256)
215 			break;
216 
217 		if (rtas_read_config(pdn, pos, 4, &header) != PCIBIOS_SUCCESSFUL)
218 			break;
219 	}
220 
221 	return 0;
222 }
223 
224 /**
225  * pseries_eeh_probe - EEH probe on the given device
226  * @pdn: PCI device node
227  * @data: Unused
228  *
229  * When EEH module is installed during system boot, all PCI devices
230  * are checked one by one to see if it supports EEH. The function
231  * is introduced for the purpose.
232  */
233 static void *pseries_eeh_probe(struct pci_dn *pdn, void *data)
234 {
235 	struct eeh_dev *edev;
236 	struct eeh_pe pe;
237 	u32 pcie_flags;
238 	int enable = 0;
239 	int ret;
240 
241 	/* Retrieve OF node and eeh device */
242 	edev = pdn_to_eeh_dev(pdn);
243 	if (!edev || edev->pe)
244 		return NULL;
245 
246 	/* Check class/vendor/device IDs */
247 	if (!pdn->vendor_id || !pdn->device_id || !pdn->class_code)
248 		return NULL;
249 
250 	/* Skip for PCI-ISA bridge */
251         if ((pdn->class_code >> 8) == PCI_CLASS_BRIDGE_ISA)
252 		return NULL;
253 
254 	eeh_edev_dbg(edev, "Probing device\n");
255 
256 	/*
257 	 * Update class code and mode of eeh device. We need
258 	 * correctly reflects that current device is root port
259 	 * or PCIe switch downstream port.
260 	 */
261 	edev->class_code = pdn->class_code;
262 	edev->pcix_cap = pseries_eeh_find_cap(pdn, PCI_CAP_ID_PCIX);
263 	edev->pcie_cap = pseries_eeh_find_cap(pdn, PCI_CAP_ID_EXP);
264 	edev->aer_cap = pseries_eeh_find_ecap(pdn, PCI_EXT_CAP_ID_ERR);
265 	edev->mode &= 0xFFFFFF00;
266 	if ((edev->class_code >> 8) == PCI_CLASS_BRIDGE_PCI) {
267 		edev->mode |= EEH_DEV_BRIDGE;
268 		if (edev->pcie_cap) {
269 			rtas_read_config(pdn, edev->pcie_cap + PCI_EXP_FLAGS,
270 					 2, &pcie_flags);
271 			pcie_flags = (pcie_flags & PCI_EXP_FLAGS_TYPE) >> 4;
272 			if (pcie_flags == PCI_EXP_TYPE_ROOT_PORT)
273 				edev->mode |= EEH_DEV_ROOT_PORT;
274 			else if (pcie_flags == PCI_EXP_TYPE_DOWNSTREAM)
275 				edev->mode |= EEH_DEV_DS_PORT;
276 		}
277 	}
278 
279 	/* Initialize the fake PE */
280 	memset(&pe, 0, sizeof(struct eeh_pe));
281 	pe.phb = pdn->phb;
282 	pe.config_addr = (pdn->busno << 16) | (pdn->devfn << 8);
283 
284 	/* Enable EEH on the device */
285 	eeh_edev_dbg(edev, "Enabling EEH on device\n");
286 	ret = eeh_ops->set_option(&pe, EEH_OPT_ENABLE);
287 	if (ret) {
288 		eeh_edev_dbg(edev, "EEH failed to enable on device (code %d)\n", ret);
289 	} else {
290 		/* Retrieve PE address */
291 		edev->pe_config_addr = eeh_ops->get_pe_addr(&pe);
292 		pe.addr = edev->pe_config_addr;
293 
294 		/* Some older systems (Power4) allow the ibm,set-eeh-option
295 		 * call to succeed even on nodes where EEH is not supported.
296 		 * Verify support explicitly.
297 		 */
298 		ret = eeh_ops->get_state(&pe, NULL);
299 		if (ret > 0 && ret != EEH_STATE_NOT_SUPPORT)
300 			enable = 1;
301 
302 		if (enable) {
303 			eeh_add_flag(EEH_ENABLED);
304 			eeh_add_to_parent_pe(edev);
305 		} else if (pdn->parent && pdn_to_eeh_dev(pdn->parent) &&
306 			   (pdn_to_eeh_dev(pdn->parent))->pe) {
307 			/* This device doesn't support EEH, but it may have an
308 			 * EEH parent, in which case we mark it as supported.
309 			 */
310 			edev->pe_config_addr = pdn_to_eeh_dev(pdn->parent)->pe_config_addr;
311 			eeh_add_to_parent_pe(edev);
312 		}
313 		eeh_edev_dbg(edev, "EEH is %s on device (code %d)\n",
314 			     (enable ? "enabled" : "unsupported"), ret);
315 	}
316 
317 	/* Save memory bars */
318 	eeh_save_bars(edev);
319 
320 	return NULL;
321 }
322 
323 /**
324  * pseries_eeh_set_option - Initialize EEH or MMIO/DMA reenable
325  * @pe: EEH PE
326  * @option: operation to be issued
327  *
328  * The function is used to control the EEH functionality globally.
329  * Currently, following options are support according to PAPR:
330  * Enable EEH, Disable EEH, Enable MMIO and Enable DMA
331  */
332 static int pseries_eeh_set_option(struct eeh_pe *pe, int option)
333 {
334 	int ret = 0;
335 	int config_addr;
336 
337 	/*
338 	 * When we're enabling or disabling EEH functioality on
339 	 * the particular PE, the PE config address is possibly
340 	 * unavailable. Therefore, we have to figure it out from
341 	 * the FDT node.
342 	 */
343 	switch (option) {
344 	case EEH_OPT_DISABLE:
345 	case EEH_OPT_ENABLE:
346 	case EEH_OPT_THAW_MMIO:
347 	case EEH_OPT_THAW_DMA:
348 		config_addr = pe->config_addr;
349 		if (pe->addr)
350 			config_addr = pe->addr;
351 		break;
352 	case EEH_OPT_FREEZE_PE:
353 		/* Not support */
354 		return 0;
355 	default:
356 		pr_err("%s: Invalid option %d\n",
357 			__func__, option);
358 		return -EINVAL;
359 	}
360 
361 	ret = rtas_call(ibm_set_eeh_option, 4, 1, NULL,
362 			config_addr, BUID_HI(pe->phb->buid),
363 			BUID_LO(pe->phb->buid), option);
364 
365 	return ret;
366 }
367 
368 /**
369  * pseries_eeh_get_pe_addr - Retrieve PE address
370  * @pe: EEH PE
371  *
372  * Retrieve the assocated PE address. Actually, there're 2 RTAS
373  * function calls dedicated for the purpose. We need implement
374  * it through the new function and then the old one. Besides,
375  * you should make sure the config address is figured out from
376  * FDT node before calling the function.
377  *
378  * It's notable that zero'ed return value means invalid PE config
379  * address.
380  */
381 static int pseries_eeh_get_pe_addr(struct eeh_pe *pe)
382 {
383 	int ret = 0;
384 	int rets[3];
385 
386 	if (ibm_get_config_addr_info2 != RTAS_UNKNOWN_SERVICE) {
387 		/*
388 		 * First of all, we need to make sure there has one PE
389 		 * associated with the device. Otherwise, PE address is
390 		 * meaningless.
391 		 */
392 		ret = rtas_call(ibm_get_config_addr_info2, 4, 2, rets,
393 				pe->config_addr, BUID_HI(pe->phb->buid),
394 				BUID_LO(pe->phb->buid), 1);
395 		if (ret || (rets[0] == 0))
396 			return 0;
397 
398 		/* Retrieve the associated PE config address */
399 		ret = rtas_call(ibm_get_config_addr_info2, 4, 2, rets,
400 				pe->config_addr, BUID_HI(pe->phb->buid),
401 				BUID_LO(pe->phb->buid), 0);
402 		if (ret) {
403 			pr_warn("%s: Failed to get address for PHB#%x-PE#%x\n",
404 				__func__, pe->phb->global_number, pe->config_addr);
405 			return 0;
406 		}
407 
408 		return rets[0];
409 	}
410 
411 	if (ibm_get_config_addr_info != RTAS_UNKNOWN_SERVICE) {
412 		ret = rtas_call(ibm_get_config_addr_info, 4, 2, rets,
413 				pe->config_addr, BUID_HI(pe->phb->buid),
414 				BUID_LO(pe->phb->buid), 0);
415 		if (ret) {
416 			pr_warn("%s: Failed to get address for PHB#%x-PE#%x\n",
417 				__func__, pe->phb->global_number, pe->config_addr);
418 			return 0;
419 		}
420 
421 		return rets[0];
422 	}
423 
424 	return ret;
425 }
426 
427 /**
428  * pseries_eeh_get_state - Retrieve PE state
429  * @pe: EEH PE
430  * @delay: suggested time to wait if state is unavailable
431  *
432  * Retrieve the state of the specified PE. On RTAS compliant
433  * pseries platform, there already has one dedicated RTAS function
434  * for the purpose. It's notable that the associated PE config address
435  * might be ready when calling the function. Therefore, endeavour to
436  * use the PE config address if possible. Further more, there're 2
437  * RTAS calls for the purpose, we need to try the new one and back
438  * to the old one if the new one couldn't work properly.
439  */
440 static int pseries_eeh_get_state(struct eeh_pe *pe, int *delay)
441 {
442 	int config_addr;
443 	int ret;
444 	int rets[4];
445 	int result;
446 
447 	/* Figure out PE config address if possible */
448 	config_addr = pe->config_addr;
449 	if (pe->addr)
450 		config_addr = pe->addr;
451 
452 	if (ibm_read_slot_reset_state2 != RTAS_UNKNOWN_SERVICE) {
453 		ret = rtas_call(ibm_read_slot_reset_state2, 3, 4, rets,
454 				config_addr, BUID_HI(pe->phb->buid),
455 				BUID_LO(pe->phb->buid));
456 	} else if (ibm_read_slot_reset_state != RTAS_UNKNOWN_SERVICE) {
457 		/* Fake PE unavailable info */
458 		rets[2] = 0;
459 		ret = rtas_call(ibm_read_slot_reset_state, 3, 3, rets,
460 				config_addr, BUID_HI(pe->phb->buid),
461 				BUID_LO(pe->phb->buid));
462 	} else {
463 		return EEH_STATE_NOT_SUPPORT;
464 	}
465 
466 	if (ret)
467 		return ret;
468 
469 	/* Parse the result out */
470 	if (!rets[1])
471 		return EEH_STATE_NOT_SUPPORT;
472 
473 	switch(rets[0]) {
474 	case 0:
475 		result = EEH_STATE_MMIO_ACTIVE |
476 			 EEH_STATE_DMA_ACTIVE;
477 		break;
478 	case 1:
479 		result = EEH_STATE_RESET_ACTIVE |
480 			 EEH_STATE_MMIO_ACTIVE  |
481 			 EEH_STATE_DMA_ACTIVE;
482 		break;
483 	case 2:
484 		result = 0;
485 		break;
486 	case 4:
487 		result = EEH_STATE_MMIO_ENABLED;
488 		break;
489 	case 5:
490 		if (rets[2]) {
491 			if (delay)
492 				*delay = rets[2];
493 			result = EEH_STATE_UNAVAILABLE;
494 		} else {
495 			result = EEH_STATE_NOT_SUPPORT;
496 		}
497 		break;
498 	default:
499 		result = EEH_STATE_NOT_SUPPORT;
500 	}
501 
502 	return result;
503 }
504 
505 /**
506  * pseries_eeh_reset - Reset the specified PE
507  * @pe: EEH PE
508  * @option: reset option
509  *
510  * Reset the specified PE
511  */
512 static int pseries_eeh_reset(struct eeh_pe *pe, int option)
513 {
514 	int config_addr;
515 	int ret;
516 
517 	/* Figure out PE address */
518 	config_addr = pe->config_addr;
519 	if (pe->addr)
520 		config_addr = pe->addr;
521 
522 	/* Reset PE through RTAS call */
523 	ret = rtas_call(ibm_set_slot_reset, 4, 1, NULL,
524 			config_addr, BUID_HI(pe->phb->buid),
525 			BUID_LO(pe->phb->buid), option);
526 
527 	/* If fundamental-reset not supported, try hot-reset */
528 	if (option == EEH_RESET_FUNDAMENTAL &&
529 	    ret == -8) {
530 		option = EEH_RESET_HOT;
531 		ret = rtas_call(ibm_set_slot_reset, 4, 1, NULL,
532 				config_addr, BUID_HI(pe->phb->buid),
533 				BUID_LO(pe->phb->buid), option);
534 	}
535 
536 	/* We need reset hold or settlement delay */
537 	if (option == EEH_RESET_FUNDAMENTAL ||
538 	    option == EEH_RESET_HOT)
539 		msleep(EEH_PE_RST_HOLD_TIME);
540 	else
541 		msleep(EEH_PE_RST_SETTLE_TIME);
542 
543 	return ret;
544 }
545 
546 /**
547  * pseries_eeh_get_log - Retrieve error log
548  * @pe: EEH PE
549  * @severity: temporary or permanent error log
550  * @drv_log: driver log to be combined with retrieved error log
551  * @len: length of driver log
552  *
553  * Retrieve the temporary or permanent error from the PE.
554  * Actually, the error will be retrieved through the dedicated
555  * RTAS call.
556  */
557 static int pseries_eeh_get_log(struct eeh_pe *pe, int severity, char *drv_log, unsigned long len)
558 {
559 	int config_addr;
560 	unsigned long flags;
561 	int ret;
562 
563 	spin_lock_irqsave(&slot_errbuf_lock, flags);
564 	memset(slot_errbuf, 0, eeh_error_buf_size);
565 
566 	/* Figure out the PE address */
567 	config_addr = pe->config_addr;
568 	if (pe->addr)
569 		config_addr = pe->addr;
570 
571 	ret = rtas_call(ibm_slot_error_detail, 8, 1, NULL, config_addr,
572 			BUID_HI(pe->phb->buid), BUID_LO(pe->phb->buid),
573 			virt_to_phys(drv_log), len,
574 			virt_to_phys(slot_errbuf), eeh_error_buf_size,
575 			severity);
576 	if (!ret)
577 		log_error(slot_errbuf, ERR_TYPE_RTAS_LOG, 0);
578 	spin_unlock_irqrestore(&slot_errbuf_lock, flags);
579 
580 	return ret;
581 }
582 
583 /**
584  * pseries_eeh_configure_bridge - Configure PCI bridges in the indicated PE
585  * @pe: EEH PE
586  *
587  * The function will be called to reconfigure the bridges included
588  * in the specified PE so that the mulfunctional PE would be recovered
589  * again.
590  */
591 static int pseries_eeh_configure_bridge(struct eeh_pe *pe)
592 {
593 	int config_addr;
594 	int ret;
595 	/* Waiting 0.2s maximum before skipping configuration */
596 	int max_wait = 200;
597 
598 	/* Figure out the PE address */
599 	config_addr = pe->config_addr;
600 	if (pe->addr)
601 		config_addr = pe->addr;
602 
603 	while (max_wait > 0) {
604 		ret = rtas_call(ibm_configure_pe, 3, 1, NULL,
605 				config_addr, BUID_HI(pe->phb->buid),
606 				BUID_LO(pe->phb->buid));
607 
608 		if (!ret)
609 			return ret;
610 
611 		/*
612 		 * If RTAS returns a delay value that's above 100ms, cut it
613 		 * down to 100ms in case firmware made a mistake.  For more
614 		 * on how these delay values work see rtas_busy_delay_time
615 		 */
616 		if (ret > RTAS_EXTENDED_DELAY_MIN+2 &&
617 		    ret <= RTAS_EXTENDED_DELAY_MAX)
618 			ret = RTAS_EXTENDED_DELAY_MIN+2;
619 
620 		max_wait -= rtas_busy_delay_time(ret);
621 
622 		if (max_wait < 0)
623 			break;
624 
625 		rtas_busy_delay(ret);
626 	}
627 
628 	pr_warn("%s: Unable to configure bridge PHB#%x-PE#%x (%d)\n",
629 		__func__, pe->phb->global_number, pe->addr, ret);
630 	return ret;
631 }
632 
633 /**
634  * pseries_eeh_read_config - Read PCI config space
635  * @pdn: PCI device node
636  * @where: PCI address
637  * @size: size to read
638  * @val: return value
639  *
640  * Read config space from the speicifed device
641  */
642 static int pseries_eeh_read_config(struct pci_dn *pdn, int where, int size, u32 *val)
643 {
644 	return rtas_read_config(pdn, where, size, val);
645 }
646 
647 /**
648  * pseries_eeh_write_config - Write PCI config space
649  * @pdn: PCI device node
650  * @where: PCI address
651  * @size: size to write
652  * @val: value to be written
653  *
654  * Write config space to the specified device
655  */
656 static int pseries_eeh_write_config(struct pci_dn *pdn, int where, int size, u32 val)
657 {
658 	return rtas_write_config(pdn, where, size, val);
659 }
660 
661 static int pseries_eeh_restore_config(struct pci_dn *pdn)
662 {
663 	struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
664 	s64 ret = 0;
665 
666 	if (!edev)
667 		return -EEXIST;
668 
669 	/*
670 	 * FIXME: The MPS, error routing rules, timeout setting are worthy
671 	 * to be exported by firmware in extendible way.
672 	 */
673 	if (edev->physfn)
674 		ret = eeh_restore_vf_config(pdn);
675 
676 	if (ret) {
677 		pr_warn("%s: Can't reinit PCI dev 0x%x (%lld)\n",
678 			__func__, edev->pe_config_addr, ret);
679 		return -EIO;
680 	}
681 
682 	return ret;
683 }
684 
685 #ifdef CONFIG_PCI_IOV
686 int pseries_send_allow_unfreeze(struct pci_dn *pdn,
687 				u16 *vf_pe_array, int cur_vfs)
688 {
689 	int rc;
690 	int ibm_allow_unfreeze = rtas_token("ibm,open-sriov-allow-unfreeze");
691 	unsigned long buid, addr;
692 
693 	addr = rtas_config_addr(pdn->busno, pdn->devfn, 0);
694 	buid = pdn->phb->buid;
695 	spin_lock(&rtas_data_buf_lock);
696 	memcpy(rtas_data_buf, vf_pe_array, RTAS_DATA_BUF_SIZE);
697 	rc = rtas_call(ibm_allow_unfreeze, 5, 1, NULL,
698 		       addr,
699 		       BUID_HI(buid),
700 		       BUID_LO(buid),
701 		       rtas_data_buf, cur_vfs * sizeof(u16));
702 	spin_unlock(&rtas_data_buf_lock);
703 	if (rc)
704 		pr_warn("%s: Failed to allow unfreeze for PHB#%x-PE#%lx, rc=%x\n",
705 			__func__,
706 			pdn->phb->global_number, addr, rc);
707 	return rc;
708 }
709 
710 static int pseries_call_allow_unfreeze(struct eeh_dev *edev)
711 {
712 	struct pci_dn *pdn, *tmp, *parent, *physfn_pdn;
713 	int cur_vfs = 0, rc = 0, vf_index, bus, devfn;
714 	u16 *vf_pe_array;
715 
716 	vf_pe_array = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
717 	if (!vf_pe_array)
718 		return -ENOMEM;
719 	if (pci_num_vf(edev->physfn ? edev->physfn : edev->pdev)) {
720 		if (edev->pdev->is_physfn) {
721 			cur_vfs = pci_num_vf(edev->pdev);
722 			pdn = eeh_dev_to_pdn(edev);
723 			parent = pdn->parent;
724 			for (vf_index = 0; vf_index < cur_vfs; vf_index++)
725 				vf_pe_array[vf_index] =
726 					cpu_to_be16(pdn->pe_num_map[vf_index]);
727 			rc = pseries_send_allow_unfreeze(pdn, vf_pe_array,
728 							 cur_vfs);
729 			pdn->last_allow_rc = rc;
730 			for (vf_index = 0; vf_index < cur_vfs; vf_index++) {
731 				list_for_each_entry_safe(pdn, tmp,
732 							 &parent->child_list,
733 							 list) {
734 					bus = pci_iov_virtfn_bus(edev->pdev,
735 								 vf_index);
736 					devfn = pci_iov_virtfn_devfn(edev->pdev,
737 								     vf_index);
738 					if (pdn->busno != bus ||
739 					    pdn->devfn != devfn)
740 						continue;
741 					pdn->last_allow_rc = rc;
742 				}
743 			}
744 		} else {
745 			pdn = pci_get_pdn(edev->pdev);
746 			vf_pe_array[0] = cpu_to_be16(pdn->pe_number);
747 			physfn_pdn = pci_get_pdn(edev->physfn);
748 			rc = pseries_send_allow_unfreeze(physfn_pdn,
749 							 vf_pe_array, 1);
750 			pdn->last_allow_rc = rc;
751 		}
752 	}
753 
754 	kfree(vf_pe_array);
755 	return rc;
756 }
757 
758 static int pseries_notify_resume(struct pci_dn *pdn)
759 {
760 	struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
761 
762 	if (!edev)
763 		return -EEXIST;
764 
765 	if (rtas_token("ibm,open-sriov-allow-unfreeze")
766 	    == RTAS_UNKNOWN_SERVICE)
767 		return -EINVAL;
768 
769 	if (edev->pdev->is_physfn || edev->pdev->is_virtfn)
770 		return pseries_call_allow_unfreeze(edev);
771 
772 	return 0;
773 }
774 #endif
775 
776 static struct eeh_ops pseries_eeh_ops = {
777 	.name			= "pseries",
778 	.init			= pseries_eeh_init,
779 	.probe			= pseries_eeh_probe,
780 	.set_option		= pseries_eeh_set_option,
781 	.get_pe_addr		= pseries_eeh_get_pe_addr,
782 	.get_state		= pseries_eeh_get_state,
783 	.reset			= pseries_eeh_reset,
784 	.get_log		= pseries_eeh_get_log,
785 	.configure_bridge       = pseries_eeh_configure_bridge,
786 	.err_inject		= NULL,
787 	.read_config		= pseries_eeh_read_config,
788 	.write_config		= pseries_eeh_write_config,
789 	.next_error		= NULL,
790 	.restore_config		= pseries_eeh_restore_config,
791 #ifdef CONFIG_PCI_IOV
792 	.notify_resume		= pseries_notify_resume
793 #endif
794 };
795 
796 /**
797  * eeh_pseries_init - Register platform dependent EEH operations
798  *
799  * EEH initialization on pseries platform. This function should be
800  * called before any EEH related functions.
801  */
802 static int __init eeh_pseries_init(void)
803 {
804 	int ret;
805 
806 	ret = eeh_ops_register(&pseries_eeh_ops);
807 	if (!ret)
808 		pr_info("EEH: pSeries platform initialized\n");
809 	else
810 		pr_info("EEH: pSeries platform initialization failure (%d)\n",
811 			ret);
812 
813 	return ret;
814 }
815 machine_early_initcall(pseries, eeh_pseries_init);
816