1 /*
2  * The file intends to implement the platform dependent EEH operations on pseries.
3  * Actually, the pseries platform is built based on RTAS heavily. That means the
4  * pseries platform dependent EEH operations will be built on RTAS calls. The functions
5  * are derived from arch/powerpc/platforms/pseries/eeh.c and necessary cleanup has
6  * been done.
7  *
8  * Copyright Benjamin Herrenschmidt & Gavin Shan, IBM Corporation 2011.
9  * Copyright IBM Corporation 2001, 2005, 2006
10  * Copyright Dave Engebretsen & Todd Inglett 2001
11  * Copyright Linas Vepstas 2005, 2006
12  *
13  * This program is free software; you can redistribute it and/or modify
14  * it under the terms of the GNU General Public License as published by
15  * the Free Software Foundation; either version 2 of the License, or
16  * (at your option) any later version.
17  *
18  * This program is distributed in the hope that it will be useful,
19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21  * GNU General Public License for more details.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with this program; if not, write to the Free Software
25  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
26  */
27 
28 #include <linux/atomic.h>
29 #include <linux/delay.h>
30 #include <linux/export.h>
31 #include <linux/init.h>
32 #include <linux/list.h>
33 #include <linux/of.h>
34 #include <linux/pci.h>
35 #include <linux/proc_fs.h>
36 #include <linux/rbtree.h>
37 #include <linux/sched.h>
38 #include <linux/seq_file.h>
39 #include <linux/spinlock.h>
40 
41 #include <asm/eeh.h>
42 #include <asm/eeh_event.h>
43 #include <asm/io.h>
44 #include <asm/machdep.h>
45 #include <asm/ppc-pci.h>
46 #include <asm/rtas.h>
47 
48 /* RTAS tokens */
49 static int ibm_set_eeh_option;
50 static int ibm_set_slot_reset;
51 static int ibm_read_slot_reset_state;
52 static int ibm_read_slot_reset_state2;
53 static int ibm_slot_error_detail;
54 static int ibm_get_config_addr_info;
55 static int ibm_get_config_addr_info2;
56 static int ibm_configure_pe;
57 
58 /*
59  * Buffer for reporting slot-error-detail rtas calls. Its here
60  * in BSS, and not dynamically alloced, so that it ends up in
61  * RMO where RTAS can access it.
62  */
63 static unsigned char slot_errbuf[RTAS_ERROR_LOG_MAX];
64 static DEFINE_SPINLOCK(slot_errbuf_lock);
65 static int eeh_error_buf_size;
66 
67 /**
68  * pseries_eeh_init - EEH platform dependent initialization
69  *
70  * EEH platform dependent initialization on pseries.
71  */
72 static int pseries_eeh_init(void)
73 {
74 	/* figure out EEH RTAS function call tokens */
75 	ibm_set_eeh_option		= rtas_token("ibm,set-eeh-option");
76 	ibm_set_slot_reset		= rtas_token("ibm,set-slot-reset");
77 	ibm_read_slot_reset_state2	= rtas_token("ibm,read-slot-reset-state2");
78 	ibm_read_slot_reset_state	= rtas_token("ibm,read-slot-reset-state");
79 	ibm_slot_error_detail		= rtas_token("ibm,slot-error-detail");
80 	ibm_get_config_addr_info2	= rtas_token("ibm,get-config-addr-info2");
81 	ibm_get_config_addr_info	= rtas_token("ibm,get-config-addr-info");
82 	ibm_configure_pe		= rtas_token("ibm,configure-pe");
83 
84 	/*
85 	 * ibm,configure-pe and ibm,configure-bridge have the same semantics,
86 	 * however ibm,configure-pe can be faster.  If we can't find
87 	 * ibm,configure-pe then fall back to using ibm,configure-bridge.
88 	 */
89 	if (ibm_configure_pe == RTAS_UNKNOWN_SERVICE)
90 		ibm_configure_pe 	= rtas_token("ibm,configure-bridge");
91 
92 	/*
93 	 * Necessary sanity check. We needn't check "get-config-addr-info"
94 	 * and its variant since the old firmware probably support address
95 	 * of domain/bus/slot/function for EEH RTAS operations.
96 	 */
97 	if (ibm_set_eeh_option == RTAS_UNKNOWN_SERVICE		||
98 	    ibm_set_slot_reset == RTAS_UNKNOWN_SERVICE		||
99 	    (ibm_read_slot_reset_state2 == RTAS_UNKNOWN_SERVICE &&
100 	     ibm_read_slot_reset_state == RTAS_UNKNOWN_SERVICE)	||
101 	    ibm_slot_error_detail == RTAS_UNKNOWN_SERVICE	||
102 	    ibm_configure_pe == RTAS_UNKNOWN_SERVICE) {
103 		pr_info("EEH functionality not supported\n");
104 		return -EINVAL;
105 	}
106 
107 	/* Initialize error log lock and size */
108 	spin_lock_init(&slot_errbuf_lock);
109 	eeh_error_buf_size = rtas_token("rtas-error-log-max");
110 	if (eeh_error_buf_size == RTAS_UNKNOWN_SERVICE) {
111 		pr_info("%s: unknown EEH error log size\n",
112 			__func__);
113 		eeh_error_buf_size = 1024;
114 	} else if (eeh_error_buf_size > RTAS_ERROR_LOG_MAX) {
115 		pr_info("%s: EEH error log size %d exceeds the maximal %d\n",
116 			__func__, eeh_error_buf_size, RTAS_ERROR_LOG_MAX);
117 		eeh_error_buf_size = RTAS_ERROR_LOG_MAX;
118 	}
119 
120 	/* Set EEH probe mode */
121 	eeh_add_flag(EEH_PROBE_MODE_DEVTREE | EEH_ENABLE_IO_FOR_LOG);
122 
123 	return 0;
124 }
125 
126 static int pseries_eeh_cap_start(struct pci_dn *pdn)
127 {
128 	u32 status;
129 
130 	if (!pdn)
131 		return 0;
132 
133 	rtas_read_config(pdn, PCI_STATUS, 2, &status);
134 	if (!(status & PCI_STATUS_CAP_LIST))
135 		return 0;
136 
137 	return PCI_CAPABILITY_LIST;
138 }
139 
140 
141 static int pseries_eeh_find_cap(struct pci_dn *pdn, int cap)
142 {
143 	int pos = pseries_eeh_cap_start(pdn);
144 	int cnt = 48;	/* Maximal number of capabilities */
145 	u32 id;
146 
147 	if (!pos)
148 		return 0;
149 
150         while (cnt--) {
151 		rtas_read_config(pdn, pos, 1, &pos);
152 		if (pos < 0x40)
153 			break;
154 		pos &= ~3;
155 		rtas_read_config(pdn, pos + PCI_CAP_LIST_ID, 1, &id);
156 		if (id == 0xff)
157 			break;
158 		if (id == cap)
159 			return pos;
160 		pos += PCI_CAP_LIST_NEXT;
161 	}
162 
163 	return 0;
164 }
165 
166 static int pseries_eeh_find_ecap(struct pci_dn *pdn, int cap)
167 {
168 	struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
169 	u32 header;
170 	int pos = 256;
171 	int ttl = (4096 - 256) / 8;
172 
173 	if (!edev || !edev->pcie_cap)
174 		return 0;
175 	if (rtas_read_config(pdn, pos, 4, &header) != PCIBIOS_SUCCESSFUL)
176 		return 0;
177 	else if (!header)
178 		return 0;
179 
180 	while (ttl-- > 0) {
181 		if (PCI_EXT_CAP_ID(header) == cap && pos)
182 			return pos;
183 
184 		pos = PCI_EXT_CAP_NEXT(header);
185 		if (pos < 256)
186 			break;
187 
188 		if (rtas_read_config(pdn, pos, 4, &header) != PCIBIOS_SUCCESSFUL)
189 			break;
190 	}
191 
192 	return 0;
193 }
194 
195 /**
196  * pseries_eeh_probe - EEH probe on the given device
197  * @pdn: PCI device node
198  * @data: Unused
199  *
200  * When EEH module is installed during system boot, all PCI devices
201  * are checked one by one to see if it supports EEH. The function
202  * is introduced for the purpose.
203  */
204 static void *pseries_eeh_probe(struct pci_dn *pdn, void *data)
205 {
206 	struct eeh_dev *edev;
207 	struct eeh_pe pe;
208 	u32 pcie_flags;
209 	int enable = 0;
210 	int ret;
211 
212 	/* Retrieve OF node and eeh device */
213 	edev = pdn_to_eeh_dev(pdn);
214 	if (!edev || edev->pe)
215 		return NULL;
216 
217 	/* Check class/vendor/device IDs */
218 	if (!pdn->vendor_id || !pdn->device_id || !pdn->class_code)
219 		return NULL;
220 
221 	/* Skip for PCI-ISA bridge */
222         if ((pdn->class_code >> 8) == PCI_CLASS_BRIDGE_ISA)
223 		return NULL;
224 
225 	/*
226 	 * Update class code and mode of eeh device. We need
227 	 * correctly reflects that current device is root port
228 	 * or PCIe switch downstream port.
229 	 */
230 	edev->class_code = pdn->class_code;
231 	edev->pcix_cap = pseries_eeh_find_cap(pdn, PCI_CAP_ID_PCIX);
232 	edev->pcie_cap = pseries_eeh_find_cap(pdn, PCI_CAP_ID_EXP);
233 	edev->aer_cap = pseries_eeh_find_ecap(pdn, PCI_EXT_CAP_ID_ERR);
234 	edev->mode &= 0xFFFFFF00;
235 	if ((edev->class_code >> 8) == PCI_CLASS_BRIDGE_PCI) {
236 		edev->mode |= EEH_DEV_BRIDGE;
237 		if (edev->pcie_cap) {
238 			rtas_read_config(pdn, edev->pcie_cap + PCI_EXP_FLAGS,
239 					 2, &pcie_flags);
240 			pcie_flags = (pcie_flags & PCI_EXP_FLAGS_TYPE) >> 4;
241 			if (pcie_flags == PCI_EXP_TYPE_ROOT_PORT)
242 				edev->mode |= EEH_DEV_ROOT_PORT;
243 			else if (pcie_flags == PCI_EXP_TYPE_DOWNSTREAM)
244 				edev->mode |= EEH_DEV_DS_PORT;
245 		}
246 	}
247 
248 	/* Initialize the fake PE */
249 	memset(&pe, 0, sizeof(struct eeh_pe));
250 	pe.phb = edev->phb;
251 	pe.config_addr = (pdn->busno << 16) | (pdn->devfn << 8);
252 
253 	/* Enable EEH on the device */
254 	ret = eeh_ops->set_option(&pe, EEH_OPT_ENABLE);
255 	if (!ret) {
256 		/* Retrieve PE address */
257 		edev->config_addr = (pdn->busno << 16) | (pdn->devfn << 8);
258 		edev->pe_config_addr = eeh_ops->get_pe_addr(&pe);
259 		pe.addr = edev->pe_config_addr;
260 
261 		/* Some older systems (Power4) allow the ibm,set-eeh-option
262 		 * call to succeed even on nodes where EEH is not supported.
263 		 * Verify support explicitly.
264 		 */
265 		ret = eeh_ops->get_state(&pe, NULL);
266 		if (ret > 0 && ret != EEH_STATE_NOT_SUPPORT)
267 			enable = 1;
268 
269 		if (enable) {
270 			eeh_add_flag(EEH_ENABLED);
271 			eeh_add_to_parent_pe(edev);
272 
273 			pr_debug("%s: EEH enabled on %02x:%02x.%01x PHB#%d-PE#%x\n",
274 				__func__, pdn->busno, PCI_SLOT(pdn->devfn),
275 				PCI_FUNC(pdn->devfn), pe.phb->global_number,
276 				pe.addr);
277 		} else if (pdn->parent && pdn_to_eeh_dev(pdn->parent) &&
278 			   (pdn_to_eeh_dev(pdn->parent))->pe) {
279 			/* This device doesn't support EEH, but it may have an
280 			 * EEH parent, in which case we mark it as supported.
281 			 */
282 			edev->config_addr = pdn_to_eeh_dev(pdn->parent)->config_addr;
283 			edev->pe_config_addr = pdn_to_eeh_dev(pdn->parent)->pe_config_addr;
284 			eeh_add_to_parent_pe(edev);
285 		}
286 	}
287 
288 	/* Save memory bars */
289 	eeh_save_bars(edev);
290 
291 	return NULL;
292 }
293 
294 /**
295  * pseries_eeh_set_option - Initialize EEH or MMIO/DMA reenable
296  * @pe: EEH PE
297  * @option: operation to be issued
298  *
299  * The function is used to control the EEH functionality globally.
300  * Currently, following options are support according to PAPR:
301  * Enable EEH, Disable EEH, Enable MMIO and Enable DMA
302  */
303 static int pseries_eeh_set_option(struct eeh_pe *pe, int option)
304 {
305 	int ret = 0;
306 	int config_addr;
307 
308 	/*
309 	 * When we're enabling or disabling EEH functioality on
310 	 * the particular PE, the PE config address is possibly
311 	 * unavailable. Therefore, we have to figure it out from
312 	 * the FDT node.
313 	 */
314 	switch (option) {
315 	case EEH_OPT_DISABLE:
316 	case EEH_OPT_ENABLE:
317 	case EEH_OPT_THAW_MMIO:
318 	case EEH_OPT_THAW_DMA:
319 		config_addr = pe->config_addr;
320 		if (pe->addr)
321 			config_addr = pe->addr;
322 		break;
323 	case EEH_OPT_FREEZE_PE:
324 		/* Not support */
325 		return 0;
326 	default:
327 		pr_err("%s: Invalid option %d\n",
328 			__func__, option);
329 		return -EINVAL;
330 	}
331 
332 	ret = rtas_call(ibm_set_eeh_option, 4, 1, NULL,
333 			config_addr, BUID_HI(pe->phb->buid),
334 			BUID_LO(pe->phb->buid), option);
335 
336 	return ret;
337 }
338 
339 /**
340  * pseries_eeh_get_pe_addr - Retrieve PE address
341  * @pe: EEH PE
342  *
343  * Retrieve the assocated PE address. Actually, there're 2 RTAS
344  * function calls dedicated for the purpose. We need implement
345  * it through the new function and then the old one. Besides,
346  * you should make sure the config address is figured out from
347  * FDT node before calling the function.
348  *
349  * It's notable that zero'ed return value means invalid PE config
350  * address.
351  */
352 static int pseries_eeh_get_pe_addr(struct eeh_pe *pe)
353 {
354 	int ret = 0;
355 	int rets[3];
356 
357 	if (ibm_get_config_addr_info2 != RTAS_UNKNOWN_SERVICE) {
358 		/*
359 		 * First of all, we need to make sure there has one PE
360 		 * associated with the device. Otherwise, PE address is
361 		 * meaningless.
362 		 */
363 		ret = rtas_call(ibm_get_config_addr_info2, 4, 2, rets,
364 				pe->config_addr, BUID_HI(pe->phb->buid),
365 				BUID_LO(pe->phb->buid), 1);
366 		if (ret || (rets[0] == 0))
367 			return 0;
368 
369 		/* Retrieve the associated PE config address */
370 		ret = rtas_call(ibm_get_config_addr_info2, 4, 2, rets,
371 				pe->config_addr, BUID_HI(pe->phb->buid),
372 				BUID_LO(pe->phb->buid), 0);
373 		if (ret) {
374 			pr_warn("%s: Failed to get address for PHB#%d-PE#%x\n",
375 				__func__, pe->phb->global_number, pe->config_addr);
376 			return 0;
377 		}
378 
379 		return rets[0];
380 	}
381 
382 	if (ibm_get_config_addr_info != RTAS_UNKNOWN_SERVICE) {
383 		ret = rtas_call(ibm_get_config_addr_info, 4, 2, rets,
384 				pe->config_addr, BUID_HI(pe->phb->buid),
385 				BUID_LO(pe->phb->buid), 0);
386 		if (ret) {
387 			pr_warn("%s: Failed to get address for PHB#%d-PE#%x\n",
388 				__func__, pe->phb->global_number, pe->config_addr);
389 			return 0;
390 		}
391 
392 		return rets[0];
393 	}
394 
395 	return ret;
396 }
397 
398 /**
399  * pseries_eeh_get_state - Retrieve PE state
400  * @pe: EEH PE
401  * @state: return value
402  *
403  * Retrieve the state of the specified PE. On RTAS compliant
404  * pseries platform, there already has one dedicated RTAS function
405  * for the purpose. It's notable that the associated PE config address
406  * might be ready when calling the function. Therefore, endeavour to
407  * use the PE config address if possible. Further more, there're 2
408  * RTAS calls for the purpose, we need to try the new one and back
409  * to the old one if the new one couldn't work properly.
410  */
411 static int pseries_eeh_get_state(struct eeh_pe *pe, int *state)
412 {
413 	int config_addr;
414 	int ret;
415 	int rets[4];
416 	int result;
417 
418 	/* Figure out PE config address if possible */
419 	config_addr = pe->config_addr;
420 	if (pe->addr)
421 		config_addr = pe->addr;
422 
423 	if (ibm_read_slot_reset_state2 != RTAS_UNKNOWN_SERVICE) {
424 		ret = rtas_call(ibm_read_slot_reset_state2, 3, 4, rets,
425 				config_addr, BUID_HI(pe->phb->buid),
426 				BUID_LO(pe->phb->buid));
427 	} else if (ibm_read_slot_reset_state != RTAS_UNKNOWN_SERVICE) {
428 		/* Fake PE unavailable info */
429 		rets[2] = 0;
430 		ret = rtas_call(ibm_read_slot_reset_state, 3, 3, rets,
431 				config_addr, BUID_HI(pe->phb->buid),
432 				BUID_LO(pe->phb->buid));
433 	} else {
434 		return EEH_STATE_NOT_SUPPORT;
435 	}
436 
437 	if (ret)
438 		return ret;
439 
440 	/* Parse the result out */
441 	if (!rets[1])
442 		return EEH_STATE_NOT_SUPPORT;
443 
444 	switch(rets[0]) {
445 	case 0:
446 		result = EEH_STATE_MMIO_ACTIVE |
447 			 EEH_STATE_DMA_ACTIVE;
448 		break;
449 	case 1:
450 		result = EEH_STATE_RESET_ACTIVE |
451 			 EEH_STATE_MMIO_ACTIVE  |
452 			 EEH_STATE_DMA_ACTIVE;
453 		break;
454 	case 2:
455 		result = 0;
456 		break;
457 	case 4:
458 		result = EEH_STATE_MMIO_ENABLED;
459 		break;
460 	case 5:
461 		if (rets[2]) {
462 			if (state) *state = rets[2];
463 			result = EEH_STATE_UNAVAILABLE;
464 		} else {
465 			result = EEH_STATE_NOT_SUPPORT;
466 		}
467 		break;
468 	default:
469 		result = EEH_STATE_NOT_SUPPORT;
470 	}
471 
472 	return result;
473 }
474 
475 /**
476  * pseries_eeh_reset - Reset the specified PE
477  * @pe: EEH PE
478  * @option: reset option
479  *
480  * Reset the specified PE
481  */
482 static int pseries_eeh_reset(struct eeh_pe *pe, int option)
483 {
484 	int config_addr;
485 	int ret;
486 
487 	/* Figure out PE address */
488 	config_addr = pe->config_addr;
489 	if (pe->addr)
490 		config_addr = pe->addr;
491 
492 	/* Reset PE through RTAS call */
493 	ret = rtas_call(ibm_set_slot_reset, 4, 1, NULL,
494 			config_addr, BUID_HI(pe->phb->buid),
495 			BUID_LO(pe->phb->buid), option);
496 
497 	/* If fundamental-reset not supported, try hot-reset */
498 	if (option == EEH_RESET_FUNDAMENTAL &&
499 	    ret == -8) {
500 		option = EEH_RESET_HOT;
501 		ret = rtas_call(ibm_set_slot_reset, 4, 1, NULL,
502 				config_addr, BUID_HI(pe->phb->buid),
503 				BUID_LO(pe->phb->buid), option);
504 	}
505 
506 	/* We need reset hold or settlement delay */
507 	if (option == EEH_RESET_FUNDAMENTAL ||
508 	    option == EEH_RESET_HOT)
509 		msleep(EEH_PE_RST_HOLD_TIME);
510 	else
511 		msleep(EEH_PE_RST_SETTLE_TIME);
512 
513 	return ret;
514 }
515 
516 /**
517  * pseries_eeh_wait_state - Wait for PE state
518  * @pe: EEH PE
519  * @max_wait: maximal period in millisecond
520  *
521  * Wait for the state of associated PE. It might take some time
522  * to retrieve the PE's state.
523  */
524 static int pseries_eeh_wait_state(struct eeh_pe *pe, int max_wait)
525 {
526 	int ret;
527 	int mwait;
528 
529 	/*
530 	 * According to PAPR, the state of PE might be temporarily
531 	 * unavailable. Under the circumstance, we have to wait
532 	 * for indicated time determined by firmware. The maximal
533 	 * wait time is 5 minutes, which is acquired from the original
534 	 * EEH implementation. Also, the original implementation
535 	 * also defined the minimal wait time as 1 second.
536 	 */
537 #define EEH_STATE_MIN_WAIT_TIME	(1000)
538 #define EEH_STATE_MAX_WAIT_TIME	(300 * 1000)
539 
540 	while (1) {
541 		ret = pseries_eeh_get_state(pe, &mwait);
542 
543 		/*
544 		 * If the PE's state is temporarily unavailable,
545 		 * we have to wait for the specified time. Otherwise,
546 		 * the PE's state will be returned immediately.
547 		 */
548 		if (ret != EEH_STATE_UNAVAILABLE)
549 			return ret;
550 
551 		if (max_wait <= 0) {
552 			pr_warn("%s: Timeout when getting PE's state (%d)\n",
553 				__func__, max_wait);
554 			return EEH_STATE_NOT_SUPPORT;
555 		}
556 
557 		if (mwait <= 0) {
558 			pr_warn("%s: Firmware returned bad wait value %d\n",
559 				__func__, mwait);
560 			mwait = EEH_STATE_MIN_WAIT_TIME;
561 		} else if (mwait > EEH_STATE_MAX_WAIT_TIME) {
562 			pr_warn("%s: Firmware returned too long wait value %d\n",
563 				__func__, mwait);
564 			mwait = EEH_STATE_MAX_WAIT_TIME;
565 		}
566 
567 		max_wait -= mwait;
568 		msleep(mwait);
569 	}
570 
571 	return EEH_STATE_NOT_SUPPORT;
572 }
573 
574 /**
575  * pseries_eeh_get_log - Retrieve error log
576  * @pe: EEH PE
577  * @severity: temporary or permanent error log
578  * @drv_log: driver log to be combined with retrieved error log
579  * @len: length of driver log
580  *
581  * Retrieve the temporary or permanent error from the PE.
582  * Actually, the error will be retrieved through the dedicated
583  * RTAS call.
584  */
585 static int pseries_eeh_get_log(struct eeh_pe *pe, int severity, char *drv_log, unsigned long len)
586 {
587 	int config_addr;
588 	unsigned long flags;
589 	int ret;
590 
591 	spin_lock_irqsave(&slot_errbuf_lock, flags);
592 	memset(slot_errbuf, 0, eeh_error_buf_size);
593 
594 	/* Figure out the PE address */
595 	config_addr = pe->config_addr;
596 	if (pe->addr)
597 		config_addr = pe->addr;
598 
599 	ret = rtas_call(ibm_slot_error_detail, 8, 1, NULL, config_addr,
600 			BUID_HI(pe->phb->buid), BUID_LO(pe->phb->buid),
601 			virt_to_phys(drv_log), len,
602 			virt_to_phys(slot_errbuf), eeh_error_buf_size,
603 			severity);
604 	if (!ret)
605 		log_error(slot_errbuf, ERR_TYPE_RTAS_LOG, 0);
606 	spin_unlock_irqrestore(&slot_errbuf_lock, flags);
607 
608 	return ret;
609 }
610 
611 /**
612  * pseries_eeh_configure_bridge - Configure PCI bridges in the indicated PE
613  * @pe: EEH PE
614  *
615  * The function will be called to reconfigure the bridges included
616  * in the specified PE so that the mulfunctional PE would be recovered
617  * again.
618  */
619 static int pseries_eeh_configure_bridge(struct eeh_pe *pe)
620 {
621 	int config_addr;
622 	int ret;
623 	/* Waiting 0.2s maximum before skipping configuration */
624 	int max_wait = 200;
625 
626 	/* Figure out the PE address */
627 	config_addr = pe->config_addr;
628 	if (pe->addr)
629 		config_addr = pe->addr;
630 
631 	while (max_wait > 0) {
632 		ret = rtas_call(ibm_configure_pe, 3, 1, NULL,
633 				config_addr, BUID_HI(pe->phb->buid),
634 				BUID_LO(pe->phb->buid));
635 
636 		if (!ret)
637 			return ret;
638 
639 		/*
640 		 * If RTAS returns a delay value that's above 100ms, cut it
641 		 * down to 100ms in case firmware made a mistake.  For more
642 		 * on how these delay values work see rtas_busy_delay_time
643 		 */
644 		if (ret > RTAS_EXTENDED_DELAY_MIN+2 &&
645 		    ret <= RTAS_EXTENDED_DELAY_MAX)
646 			ret = RTAS_EXTENDED_DELAY_MIN+2;
647 
648 		max_wait -= rtas_busy_delay_time(ret);
649 
650 		if (max_wait < 0)
651 			break;
652 
653 		rtas_busy_delay(ret);
654 	}
655 
656 	pr_warn("%s: Unable to configure bridge PHB#%d-PE#%x (%d)\n",
657 		__func__, pe->phb->global_number, pe->addr, ret);
658 	return ret;
659 }
660 
661 /**
662  * pseries_eeh_read_config - Read PCI config space
663  * @pdn: PCI device node
664  * @where: PCI address
665  * @size: size to read
666  * @val: return value
667  *
668  * Read config space from the speicifed device
669  */
670 static int pseries_eeh_read_config(struct pci_dn *pdn, int where, int size, u32 *val)
671 {
672 	return rtas_read_config(pdn, where, size, val);
673 }
674 
675 /**
676  * pseries_eeh_write_config - Write PCI config space
677  * @pdn: PCI device node
678  * @where: PCI address
679  * @size: size to write
680  * @val: value to be written
681  *
682  * Write config space to the specified device
683  */
684 static int pseries_eeh_write_config(struct pci_dn *pdn, int where, int size, u32 val)
685 {
686 	return rtas_write_config(pdn, where, size, val);
687 }
688 
689 static struct eeh_ops pseries_eeh_ops = {
690 	.name			= "pseries",
691 	.init			= pseries_eeh_init,
692 	.probe			= pseries_eeh_probe,
693 	.set_option		= pseries_eeh_set_option,
694 	.get_pe_addr		= pseries_eeh_get_pe_addr,
695 	.get_state		= pseries_eeh_get_state,
696 	.reset			= pseries_eeh_reset,
697 	.wait_state		= pseries_eeh_wait_state,
698 	.get_log		= pseries_eeh_get_log,
699 	.configure_bridge       = pseries_eeh_configure_bridge,
700 	.err_inject		= NULL,
701 	.read_config		= pseries_eeh_read_config,
702 	.write_config		= pseries_eeh_write_config,
703 	.next_error		= NULL,
704 	.restore_config		= NULL
705 };
706 
707 /**
708  * eeh_pseries_init - Register platform dependent EEH operations
709  *
710  * EEH initialization on pseries platform. This function should be
711  * called before any EEH related functions.
712  */
713 static int __init eeh_pseries_init(void)
714 {
715 	int ret;
716 
717 	ret = eeh_ops_register(&pseries_eeh_ops);
718 	if (!ret)
719 		pr_info("EEH: pSeries platform initialized\n");
720 	else
721 		pr_info("EEH: pSeries platform initialization failure (%d)\n",
722 			ret);
723 
724 	return ret;
725 }
726 machine_early_initcall(pseries, eeh_pseries_init);
727