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 = pdn->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->pe_config_addr = eeh_ops->get_pe_addr(&pe);
258 		pe.addr = edev->pe_config_addr;
259 
260 		/* Some older systems (Power4) allow the ibm,set-eeh-option
261 		 * call to succeed even on nodes where EEH is not supported.
262 		 * Verify support explicitly.
263 		 */
264 		ret = eeh_ops->get_state(&pe, NULL);
265 		if (ret > 0 && ret != EEH_STATE_NOT_SUPPORT)
266 			enable = 1;
267 
268 		if (enable) {
269 			eeh_add_flag(EEH_ENABLED);
270 			eeh_add_to_parent_pe(edev);
271 
272 			pr_debug("%s: EEH enabled on %02x:%02x.%01x PHB#%x-PE#%x\n",
273 				__func__, pdn->busno, PCI_SLOT(pdn->devfn),
274 				PCI_FUNC(pdn->devfn), pe.phb->global_number,
275 				pe.addr);
276 		} else if (pdn->parent && pdn_to_eeh_dev(pdn->parent) &&
277 			   (pdn_to_eeh_dev(pdn->parent))->pe) {
278 			/* This device doesn't support EEH, but it may have an
279 			 * EEH parent, in which case we mark it as supported.
280 			 */
281 			edev->pe_config_addr = pdn_to_eeh_dev(pdn->parent)->pe_config_addr;
282 			eeh_add_to_parent_pe(edev);
283 		}
284 	}
285 
286 	/* Save memory bars */
287 	eeh_save_bars(edev);
288 
289 	return NULL;
290 }
291 
292 /**
293  * pseries_eeh_set_option - Initialize EEH or MMIO/DMA reenable
294  * @pe: EEH PE
295  * @option: operation to be issued
296  *
297  * The function is used to control the EEH functionality globally.
298  * Currently, following options are support according to PAPR:
299  * Enable EEH, Disable EEH, Enable MMIO and Enable DMA
300  */
301 static int pseries_eeh_set_option(struct eeh_pe *pe, int option)
302 {
303 	int ret = 0;
304 	int config_addr;
305 
306 	/*
307 	 * When we're enabling or disabling EEH functioality on
308 	 * the particular PE, the PE config address is possibly
309 	 * unavailable. Therefore, we have to figure it out from
310 	 * the FDT node.
311 	 */
312 	switch (option) {
313 	case EEH_OPT_DISABLE:
314 	case EEH_OPT_ENABLE:
315 	case EEH_OPT_THAW_MMIO:
316 	case EEH_OPT_THAW_DMA:
317 		config_addr = pe->config_addr;
318 		if (pe->addr)
319 			config_addr = pe->addr;
320 		break;
321 	case EEH_OPT_FREEZE_PE:
322 		/* Not support */
323 		return 0;
324 	default:
325 		pr_err("%s: Invalid option %d\n",
326 			__func__, option);
327 		return -EINVAL;
328 	}
329 
330 	ret = rtas_call(ibm_set_eeh_option, 4, 1, NULL,
331 			config_addr, BUID_HI(pe->phb->buid),
332 			BUID_LO(pe->phb->buid), option);
333 
334 	return ret;
335 }
336 
337 /**
338  * pseries_eeh_get_pe_addr - Retrieve PE address
339  * @pe: EEH PE
340  *
341  * Retrieve the assocated PE address. Actually, there're 2 RTAS
342  * function calls dedicated for the purpose. We need implement
343  * it through the new function and then the old one. Besides,
344  * you should make sure the config address is figured out from
345  * FDT node before calling the function.
346  *
347  * It's notable that zero'ed return value means invalid PE config
348  * address.
349  */
350 static int pseries_eeh_get_pe_addr(struct eeh_pe *pe)
351 {
352 	int ret = 0;
353 	int rets[3];
354 
355 	if (ibm_get_config_addr_info2 != RTAS_UNKNOWN_SERVICE) {
356 		/*
357 		 * First of all, we need to make sure there has one PE
358 		 * associated with the device. Otherwise, PE address is
359 		 * meaningless.
360 		 */
361 		ret = rtas_call(ibm_get_config_addr_info2, 4, 2, rets,
362 				pe->config_addr, BUID_HI(pe->phb->buid),
363 				BUID_LO(pe->phb->buid), 1);
364 		if (ret || (rets[0] == 0))
365 			return 0;
366 
367 		/* Retrieve the associated PE config address */
368 		ret = rtas_call(ibm_get_config_addr_info2, 4, 2, rets,
369 				pe->config_addr, BUID_HI(pe->phb->buid),
370 				BUID_LO(pe->phb->buid), 0);
371 		if (ret) {
372 			pr_warn("%s: Failed to get address for PHB#%x-PE#%x\n",
373 				__func__, pe->phb->global_number, pe->config_addr);
374 			return 0;
375 		}
376 
377 		return rets[0];
378 	}
379 
380 	if (ibm_get_config_addr_info != RTAS_UNKNOWN_SERVICE) {
381 		ret = rtas_call(ibm_get_config_addr_info, 4, 2, rets,
382 				pe->config_addr, BUID_HI(pe->phb->buid),
383 				BUID_LO(pe->phb->buid), 0);
384 		if (ret) {
385 			pr_warn("%s: Failed to get address for PHB#%x-PE#%x\n",
386 				__func__, pe->phb->global_number, pe->config_addr);
387 			return 0;
388 		}
389 
390 		return rets[0];
391 	}
392 
393 	return ret;
394 }
395 
396 /**
397  * pseries_eeh_get_state - Retrieve PE state
398  * @pe: EEH PE
399  * @state: return value
400  *
401  * Retrieve the state of the specified PE. On RTAS compliant
402  * pseries platform, there already has one dedicated RTAS function
403  * for the purpose. It's notable that the associated PE config address
404  * might be ready when calling the function. Therefore, endeavour to
405  * use the PE config address if possible. Further more, there're 2
406  * RTAS calls for the purpose, we need to try the new one and back
407  * to the old one if the new one couldn't work properly.
408  */
409 static int pseries_eeh_get_state(struct eeh_pe *pe, int *state)
410 {
411 	int config_addr;
412 	int ret;
413 	int rets[4];
414 	int result;
415 
416 	/* Figure out PE config address if possible */
417 	config_addr = pe->config_addr;
418 	if (pe->addr)
419 		config_addr = pe->addr;
420 
421 	if (ibm_read_slot_reset_state2 != RTAS_UNKNOWN_SERVICE) {
422 		ret = rtas_call(ibm_read_slot_reset_state2, 3, 4, rets,
423 				config_addr, BUID_HI(pe->phb->buid),
424 				BUID_LO(pe->phb->buid));
425 	} else if (ibm_read_slot_reset_state != RTAS_UNKNOWN_SERVICE) {
426 		/* Fake PE unavailable info */
427 		rets[2] = 0;
428 		ret = rtas_call(ibm_read_slot_reset_state, 3, 3, rets,
429 				config_addr, BUID_HI(pe->phb->buid),
430 				BUID_LO(pe->phb->buid));
431 	} else {
432 		return EEH_STATE_NOT_SUPPORT;
433 	}
434 
435 	if (ret)
436 		return ret;
437 
438 	/* Parse the result out */
439 	if (!rets[1])
440 		return EEH_STATE_NOT_SUPPORT;
441 
442 	switch(rets[0]) {
443 	case 0:
444 		result = EEH_STATE_MMIO_ACTIVE |
445 			 EEH_STATE_DMA_ACTIVE;
446 		break;
447 	case 1:
448 		result = EEH_STATE_RESET_ACTIVE |
449 			 EEH_STATE_MMIO_ACTIVE  |
450 			 EEH_STATE_DMA_ACTIVE;
451 		break;
452 	case 2:
453 		result = 0;
454 		break;
455 	case 4:
456 		result = EEH_STATE_MMIO_ENABLED;
457 		break;
458 	case 5:
459 		if (rets[2]) {
460 			if (state) *state = rets[2];
461 			result = EEH_STATE_UNAVAILABLE;
462 		} else {
463 			result = EEH_STATE_NOT_SUPPORT;
464 		}
465 		break;
466 	default:
467 		result = EEH_STATE_NOT_SUPPORT;
468 	}
469 
470 	return result;
471 }
472 
473 /**
474  * pseries_eeh_reset - Reset the specified PE
475  * @pe: EEH PE
476  * @option: reset option
477  *
478  * Reset the specified PE
479  */
480 static int pseries_eeh_reset(struct eeh_pe *pe, int option)
481 {
482 	int config_addr;
483 	int ret;
484 
485 	/* Figure out PE address */
486 	config_addr = pe->config_addr;
487 	if (pe->addr)
488 		config_addr = pe->addr;
489 
490 	/* Reset PE through RTAS call */
491 	ret = rtas_call(ibm_set_slot_reset, 4, 1, NULL,
492 			config_addr, BUID_HI(pe->phb->buid),
493 			BUID_LO(pe->phb->buid), option);
494 
495 	/* If fundamental-reset not supported, try hot-reset */
496 	if (option == EEH_RESET_FUNDAMENTAL &&
497 	    ret == -8) {
498 		option = EEH_RESET_HOT;
499 		ret = rtas_call(ibm_set_slot_reset, 4, 1, NULL,
500 				config_addr, BUID_HI(pe->phb->buid),
501 				BUID_LO(pe->phb->buid), option);
502 	}
503 
504 	/* We need reset hold or settlement delay */
505 	if (option == EEH_RESET_FUNDAMENTAL ||
506 	    option == EEH_RESET_HOT)
507 		msleep(EEH_PE_RST_HOLD_TIME);
508 	else
509 		msleep(EEH_PE_RST_SETTLE_TIME);
510 
511 	return ret;
512 }
513 
514 /**
515  * pseries_eeh_wait_state - Wait for PE state
516  * @pe: EEH PE
517  * @max_wait: maximal period in millisecond
518  *
519  * Wait for the state of associated PE. It might take some time
520  * to retrieve the PE's state.
521  */
522 static int pseries_eeh_wait_state(struct eeh_pe *pe, int max_wait)
523 {
524 	int ret;
525 	int mwait;
526 
527 	/*
528 	 * According to PAPR, the state of PE might be temporarily
529 	 * unavailable. Under the circumstance, we have to wait
530 	 * for indicated time determined by firmware. The maximal
531 	 * wait time is 5 minutes, which is acquired from the original
532 	 * EEH implementation. Also, the original implementation
533 	 * also defined the minimal wait time as 1 second.
534 	 */
535 #define EEH_STATE_MIN_WAIT_TIME	(1000)
536 #define EEH_STATE_MAX_WAIT_TIME	(300 * 1000)
537 
538 	while (1) {
539 		ret = pseries_eeh_get_state(pe, &mwait);
540 
541 		/*
542 		 * If the PE's state is temporarily unavailable,
543 		 * we have to wait for the specified time. Otherwise,
544 		 * the PE's state will be returned immediately.
545 		 */
546 		if (ret != EEH_STATE_UNAVAILABLE)
547 			return ret;
548 
549 		if (max_wait <= 0) {
550 			pr_warn("%s: Timeout when getting PE's state (%d)\n",
551 				__func__, max_wait);
552 			return EEH_STATE_NOT_SUPPORT;
553 		}
554 
555 		if (mwait <= 0) {
556 			pr_warn("%s: Firmware returned bad wait value %d\n",
557 				__func__, mwait);
558 			mwait = EEH_STATE_MIN_WAIT_TIME;
559 		} else if (mwait > EEH_STATE_MAX_WAIT_TIME) {
560 			pr_warn("%s: Firmware returned too long wait value %d\n",
561 				__func__, mwait);
562 			mwait = EEH_STATE_MAX_WAIT_TIME;
563 		}
564 
565 		max_wait -= mwait;
566 		msleep(mwait);
567 	}
568 
569 	return EEH_STATE_NOT_SUPPORT;
570 }
571 
572 /**
573  * pseries_eeh_get_log - Retrieve error log
574  * @pe: EEH PE
575  * @severity: temporary or permanent error log
576  * @drv_log: driver log to be combined with retrieved error log
577  * @len: length of driver log
578  *
579  * Retrieve the temporary or permanent error from the PE.
580  * Actually, the error will be retrieved through the dedicated
581  * RTAS call.
582  */
583 static int pseries_eeh_get_log(struct eeh_pe *pe, int severity, char *drv_log, unsigned long len)
584 {
585 	int config_addr;
586 	unsigned long flags;
587 	int ret;
588 
589 	spin_lock_irqsave(&slot_errbuf_lock, flags);
590 	memset(slot_errbuf, 0, eeh_error_buf_size);
591 
592 	/* Figure out the PE address */
593 	config_addr = pe->config_addr;
594 	if (pe->addr)
595 		config_addr = pe->addr;
596 
597 	ret = rtas_call(ibm_slot_error_detail, 8, 1, NULL, config_addr,
598 			BUID_HI(pe->phb->buid), BUID_LO(pe->phb->buid),
599 			virt_to_phys(drv_log), len,
600 			virt_to_phys(slot_errbuf), eeh_error_buf_size,
601 			severity);
602 	if (!ret)
603 		log_error(slot_errbuf, ERR_TYPE_RTAS_LOG, 0);
604 	spin_unlock_irqrestore(&slot_errbuf_lock, flags);
605 
606 	return ret;
607 }
608 
609 /**
610  * pseries_eeh_configure_bridge - Configure PCI bridges in the indicated PE
611  * @pe: EEH PE
612  *
613  * The function will be called to reconfigure the bridges included
614  * in the specified PE so that the mulfunctional PE would be recovered
615  * again.
616  */
617 static int pseries_eeh_configure_bridge(struct eeh_pe *pe)
618 {
619 	int config_addr;
620 	int ret;
621 	/* Waiting 0.2s maximum before skipping configuration */
622 	int max_wait = 200;
623 
624 	/* Figure out the PE address */
625 	config_addr = pe->config_addr;
626 	if (pe->addr)
627 		config_addr = pe->addr;
628 
629 	while (max_wait > 0) {
630 		ret = rtas_call(ibm_configure_pe, 3, 1, NULL,
631 				config_addr, BUID_HI(pe->phb->buid),
632 				BUID_LO(pe->phb->buid));
633 
634 		if (!ret)
635 			return ret;
636 
637 		/*
638 		 * If RTAS returns a delay value that's above 100ms, cut it
639 		 * down to 100ms in case firmware made a mistake.  For more
640 		 * on how these delay values work see rtas_busy_delay_time
641 		 */
642 		if (ret > RTAS_EXTENDED_DELAY_MIN+2 &&
643 		    ret <= RTAS_EXTENDED_DELAY_MAX)
644 			ret = RTAS_EXTENDED_DELAY_MIN+2;
645 
646 		max_wait -= rtas_busy_delay_time(ret);
647 
648 		if (max_wait < 0)
649 			break;
650 
651 		rtas_busy_delay(ret);
652 	}
653 
654 	pr_warn("%s: Unable to configure bridge PHB#%x-PE#%x (%d)\n",
655 		__func__, pe->phb->global_number, pe->addr, ret);
656 	return ret;
657 }
658 
659 /**
660  * pseries_eeh_read_config - Read PCI config space
661  * @pdn: PCI device node
662  * @where: PCI address
663  * @size: size to read
664  * @val: return value
665  *
666  * Read config space from the speicifed device
667  */
668 static int pseries_eeh_read_config(struct pci_dn *pdn, int where, int size, u32 *val)
669 {
670 	return rtas_read_config(pdn, where, size, val);
671 }
672 
673 /**
674  * pseries_eeh_write_config - Write PCI config space
675  * @pdn: PCI device node
676  * @where: PCI address
677  * @size: size to write
678  * @val: value to be written
679  *
680  * Write config space to the specified device
681  */
682 static int pseries_eeh_write_config(struct pci_dn *pdn, int where, int size, u32 val)
683 {
684 	return rtas_write_config(pdn, where, size, val);
685 }
686 
687 static struct eeh_ops pseries_eeh_ops = {
688 	.name			= "pseries",
689 	.init			= pseries_eeh_init,
690 	.probe			= pseries_eeh_probe,
691 	.set_option		= pseries_eeh_set_option,
692 	.get_pe_addr		= pseries_eeh_get_pe_addr,
693 	.get_state		= pseries_eeh_get_state,
694 	.reset			= pseries_eeh_reset,
695 	.wait_state		= pseries_eeh_wait_state,
696 	.get_log		= pseries_eeh_get_log,
697 	.configure_bridge       = pseries_eeh_configure_bridge,
698 	.err_inject		= NULL,
699 	.read_config		= pseries_eeh_read_config,
700 	.write_config		= pseries_eeh_write_config,
701 	.next_error		= NULL,
702 	.restore_config		= NULL
703 };
704 
705 /**
706  * eeh_pseries_init - Register platform dependent EEH operations
707  *
708  * EEH initialization on pseries platform. This function should be
709  * called before any EEH related functions.
710  */
711 static int __init eeh_pseries_init(void)
712 {
713 	int ret;
714 
715 	ret = eeh_ops_register(&pseries_eeh_ops);
716 	if (!ret)
717 		pr_info("EEH: pSeries platform initialized\n");
718 	else
719 		pr_info("EEH: pSeries platform initialization failure (%d)\n",
720 			ret);
721 
722 	return ret;
723 }
724 machine_early_initcall(pseries, eeh_pseries_init);
725