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 #ifdef CONFIG_PCI_IOV
59 void pseries_pcibios_bus_add_device(struct pci_dev *pdev)
60 {
61 	struct pci_dn *pdn = pci_get_pdn(pdev);
62 	struct pci_dn *physfn_pdn;
63 	struct eeh_dev *edev;
64 
65 	if (!pdev->is_virtfn)
66 		return;
67 
68 	pdn->device_id  =  pdev->device;
69 	pdn->vendor_id  =  pdev->vendor;
70 	pdn->class_code =  pdev->class;
71 	/*
72 	 * Last allow unfreeze return code used for retrieval
73 	 * by user space in eeh-sysfs to show the last command
74 	 * completion from platform.
75 	 */
76 	pdn->last_allow_rc =  0;
77 	physfn_pdn      =  pci_get_pdn(pdev->physfn);
78 	pdn->pe_number  =  physfn_pdn->pe_num_map[pdn->vf_index];
79 	edev = pdn_to_eeh_dev(pdn);
80 
81 	/*
82 	 * The following operations will fail if VF's sysfs files
83 	 * aren't created or its resources aren't finalized.
84 	 */
85 	eeh_add_device_early(pdn);
86 	eeh_add_device_late(pdev);
87 	edev->pe_config_addr =  (pdn->busno << 16) | (pdn->devfn << 8);
88 	eeh_rmv_from_parent_pe(edev); /* Remove as it is adding to bus pe */
89 	eeh_add_to_parent_pe(edev);   /* Add as VF PE type */
90 	eeh_sysfs_add_device(pdev);
91 
92 }
93 #endif
94 
95 /*
96  * Buffer for reporting slot-error-detail rtas calls. Its here
97  * in BSS, and not dynamically alloced, so that it ends up in
98  * RMO where RTAS can access it.
99  */
100 static unsigned char slot_errbuf[RTAS_ERROR_LOG_MAX];
101 static DEFINE_SPINLOCK(slot_errbuf_lock);
102 static int eeh_error_buf_size;
103 
104 /**
105  * pseries_eeh_init - EEH platform dependent initialization
106  *
107  * EEH platform dependent initialization on pseries.
108  */
109 static int pseries_eeh_init(void)
110 {
111 	/* figure out EEH RTAS function call tokens */
112 	ibm_set_eeh_option		= rtas_token("ibm,set-eeh-option");
113 	ibm_set_slot_reset		= rtas_token("ibm,set-slot-reset");
114 	ibm_read_slot_reset_state2	= rtas_token("ibm,read-slot-reset-state2");
115 	ibm_read_slot_reset_state	= rtas_token("ibm,read-slot-reset-state");
116 	ibm_slot_error_detail		= rtas_token("ibm,slot-error-detail");
117 	ibm_get_config_addr_info2	= rtas_token("ibm,get-config-addr-info2");
118 	ibm_get_config_addr_info	= rtas_token("ibm,get-config-addr-info");
119 	ibm_configure_pe		= rtas_token("ibm,configure-pe");
120 
121 	/*
122 	 * ibm,configure-pe and ibm,configure-bridge have the same semantics,
123 	 * however ibm,configure-pe can be faster.  If we can't find
124 	 * ibm,configure-pe then fall back to using ibm,configure-bridge.
125 	 */
126 	if (ibm_configure_pe == RTAS_UNKNOWN_SERVICE)
127 		ibm_configure_pe 	= rtas_token("ibm,configure-bridge");
128 
129 	/*
130 	 * Necessary sanity check. We needn't check "get-config-addr-info"
131 	 * and its variant since the old firmware probably support address
132 	 * of domain/bus/slot/function for EEH RTAS operations.
133 	 */
134 	if (ibm_set_eeh_option == RTAS_UNKNOWN_SERVICE		||
135 	    ibm_set_slot_reset == RTAS_UNKNOWN_SERVICE		||
136 	    (ibm_read_slot_reset_state2 == RTAS_UNKNOWN_SERVICE &&
137 	     ibm_read_slot_reset_state == RTAS_UNKNOWN_SERVICE)	||
138 	    ibm_slot_error_detail == RTAS_UNKNOWN_SERVICE	||
139 	    ibm_configure_pe == RTAS_UNKNOWN_SERVICE) {
140 		pr_info("EEH functionality not supported\n");
141 		return -EINVAL;
142 	}
143 
144 	/* Initialize error log lock and size */
145 	spin_lock_init(&slot_errbuf_lock);
146 	eeh_error_buf_size = rtas_token("rtas-error-log-max");
147 	if (eeh_error_buf_size == RTAS_UNKNOWN_SERVICE) {
148 		pr_info("%s: unknown EEH error log size\n",
149 			__func__);
150 		eeh_error_buf_size = 1024;
151 	} else if (eeh_error_buf_size > RTAS_ERROR_LOG_MAX) {
152 		pr_info("%s: EEH error log size %d exceeds the maximal %d\n",
153 			__func__, eeh_error_buf_size, RTAS_ERROR_LOG_MAX);
154 		eeh_error_buf_size = RTAS_ERROR_LOG_MAX;
155 	}
156 
157 	/* Set EEH probe mode */
158 	eeh_add_flag(EEH_PROBE_MODE_DEVTREE | EEH_ENABLE_IO_FOR_LOG);
159 
160 #ifdef CONFIG_PCI_IOV
161 	/* Set EEH machine dependent code */
162 	ppc_md.pcibios_bus_add_device = pseries_pcibios_bus_add_device;
163 #endif
164 
165 	return 0;
166 }
167 
168 static int pseries_eeh_cap_start(struct pci_dn *pdn)
169 {
170 	u32 status;
171 
172 	if (!pdn)
173 		return 0;
174 
175 	rtas_read_config(pdn, PCI_STATUS, 2, &status);
176 	if (!(status & PCI_STATUS_CAP_LIST))
177 		return 0;
178 
179 	return PCI_CAPABILITY_LIST;
180 }
181 
182 
183 static int pseries_eeh_find_cap(struct pci_dn *pdn, int cap)
184 {
185 	int pos = pseries_eeh_cap_start(pdn);
186 	int cnt = 48;	/* Maximal number of capabilities */
187 	u32 id;
188 
189 	if (!pos)
190 		return 0;
191 
192         while (cnt--) {
193 		rtas_read_config(pdn, pos, 1, &pos);
194 		if (pos < 0x40)
195 			break;
196 		pos &= ~3;
197 		rtas_read_config(pdn, pos + PCI_CAP_LIST_ID, 1, &id);
198 		if (id == 0xff)
199 			break;
200 		if (id == cap)
201 			return pos;
202 		pos += PCI_CAP_LIST_NEXT;
203 	}
204 
205 	return 0;
206 }
207 
208 static int pseries_eeh_find_ecap(struct pci_dn *pdn, int cap)
209 {
210 	struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
211 	u32 header;
212 	int pos = 256;
213 	int ttl = (4096 - 256) / 8;
214 
215 	if (!edev || !edev->pcie_cap)
216 		return 0;
217 	if (rtas_read_config(pdn, pos, 4, &header) != PCIBIOS_SUCCESSFUL)
218 		return 0;
219 	else if (!header)
220 		return 0;
221 
222 	while (ttl-- > 0) {
223 		if (PCI_EXT_CAP_ID(header) == cap && pos)
224 			return pos;
225 
226 		pos = PCI_EXT_CAP_NEXT(header);
227 		if (pos < 256)
228 			break;
229 
230 		if (rtas_read_config(pdn, pos, 4, &header) != PCIBIOS_SUCCESSFUL)
231 			break;
232 	}
233 
234 	return 0;
235 }
236 
237 /**
238  * pseries_eeh_probe - EEH probe on the given device
239  * @pdn: PCI device node
240  * @data: Unused
241  *
242  * When EEH module is installed during system boot, all PCI devices
243  * are checked one by one to see if it supports EEH. The function
244  * is introduced for the purpose.
245  */
246 static void *pseries_eeh_probe(struct pci_dn *pdn, void *data)
247 {
248 	struct eeh_dev *edev;
249 	struct eeh_pe pe;
250 	u32 pcie_flags;
251 	int enable = 0;
252 	int ret;
253 
254 	/* Retrieve OF node and eeh device */
255 	edev = pdn_to_eeh_dev(pdn);
256 	if (!edev || edev->pe)
257 		return NULL;
258 
259 	/* Check class/vendor/device IDs */
260 	if (!pdn->vendor_id || !pdn->device_id || !pdn->class_code)
261 		return NULL;
262 
263 	/* Skip for PCI-ISA bridge */
264         if ((pdn->class_code >> 8) == PCI_CLASS_BRIDGE_ISA)
265 		return NULL;
266 
267 	/*
268 	 * Update class code and mode of eeh device. We need
269 	 * correctly reflects that current device is root port
270 	 * or PCIe switch downstream port.
271 	 */
272 	edev->class_code = pdn->class_code;
273 	edev->pcix_cap = pseries_eeh_find_cap(pdn, PCI_CAP_ID_PCIX);
274 	edev->pcie_cap = pseries_eeh_find_cap(pdn, PCI_CAP_ID_EXP);
275 	edev->aer_cap = pseries_eeh_find_ecap(pdn, PCI_EXT_CAP_ID_ERR);
276 	edev->mode &= 0xFFFFFF00;
277 	if ((edev->class_code >> 8) == PCI_CLASS_BRIDGE_PCI) {
278 		edev->mode |= EEH_DEV_BRIDGE;
279 		if (edev->pcie_cap) {
280 			rtas_read_config(pdn, edev->pcie_cap + PCI_EXP_FLAGS,
281 					 2, &pcie_flags);
282 			pcie_flags = (pcie_flags & PCI_EXP_FLAGS_TYPE) >> 4;
283 			if (pcie_flags == PCI_EXP_TYPE_ROOT_PORT)
284 				edev->mode |= EEH_DEV_ROOT_PORT;
285 			else if (pcie_flags == PCI_EXP_TYPE_DOWNSTREAM)
286 				edev->mode |= EEH_DEV_DS_PORT;
287 		}
288 	}
289 
290 	/* Initialize the fake PE */
291 	memset(&pe, 0, sizeof(struct eeh_pe));
292 	pe.phb = pdn->phb;
293 	pe.config_addr = (pdn->busno << 16) | (pdn->devfn << 8);
294 
295 	/* Enable EEH on the device */
296 	ret = eeh_ops->set_option(&pe, EEH_OPT_ENABLE);
297 	if (!ret) {
298 		/* Retrieve PE address */
299 		edev->pe_config_addr = eeh_ops->get_pe_addr(&pe);
300 		pe.addr = edev->pe_config_addr;
301 
302 		/* Some older systems (Power4) allow the ibm,set-eeh-option
303 		 * call to succeed even on nodes where EEH is not supported.
304 		 * Verify support explicitly.
305 		 */
306 		ret = eeh_ops->get_state(&pe, NULL);
307 		if (ret > 0 && ret != EEH_STATE_NOT_SUPPORT)
308 			enable = 1;
309 
310 		if (enable) {
311 			eeh_add_flag(EEH_ENABLED);
312 			eeh_add_to_parent_pe(edev);
313 
314 			pr_debug("%s: EEH enabled on %02x:%02x.%01x PHB#%x-PE#%x\n",
315 				__func__, pdn->busno, PCI_SLOT(pdn->devfn),
316 				PCI_FUNC(pdn->devfn), pe.phb->global_number,
317 				pe.addr);
318 		} else if (pdn->parent && pdn_to_eeh_dev(pdn->parent) &&
319 			   (pdn_to_eeh_dev(pdn->parent))->pe) {
320 			/* This device doesn't support EEH, but it may have an
321 			 * EEH parent, in which case we mark it as supported.
322 			 */
323 			edev->pe_config_addr = pdn_to_eeh_dev(pdn->parent)->pe_config_addr;
324 			eeh_add_to_parent_pe(edev);
325 		}
326 	}
327 
328 	/* Save memory bars */
329 	eeh_save_bars(edev);
330 
331 	return NULL;
332 }
333 
334 /**
335  * pseries_eeh_set_option - Initialize EEH or MMIO/DMA reenable
336  * @pe: EEH PE
337  * @option: operation to be issued
338  *
339  * The function is used to control the EEH functionality globally.
340  * Currently, following options are support according to PAPR:
341  * Enable EEH, Disable EEH, Enable MMIO and Enable DMA
342  */
343 static int pseries_eeh_set_option(struct eeh_pe *pe, int option)
344 {
345 	int ret = 0;
346 	int config_addr;
347 
348 	/*
349 	 * When we're enabling or disabling EEH functioality on
350 	 * the particular PE, the PE config address is possibly
351 	 * unavailable. Therefore, we have to figure it out from
352 	 * the FDT node.
353 	 */
354 	switch (option) {
355 	case EEH_OPT_DISABLE:
356 	case EEH_OPT_ENABLE:
357 	case EEH_OPT_THAW_MMIO:
358 	case EEH_OPT_THAW_DMA:
359 		config_addr = pe->config_addr;
360 		if (pe->addr)
361 			config_addr = pe->addr;
362 		break;
363 	case EEH_OPT_FREEZE_PE:
364 		/* Not support */
365 		return 0;
366 	default:
367 		pr_err("%s: Invalid option %d\n",
368 			__func__, option);
369 		return -EINVAL;
370 	}
371 
372 	ret = rtas_call(ibm_set_eeh_option, 4, 1, NULL,
373 			config_addr, BUID_HI(pe->phb->buid),
374 			BUID_LO(pe->phb->buid), option);
375 
376 	return ret;
377 }
378 
379 /**
380  * pseries_eeh_get_pe_addr - Retrieve PE address
381  * @pe: EEH PE
382  *
383  * Retrieve the assocated PE address. Actually, there're 2 RTAS
384  * function calls dedicated for the purpose. We need implement
385  * it through the new function and then the old one. Besides,
386  * you should make sure the config address is figured out from
387  * FDT node before calling the function.
388  *
389  * It's notable that zero'ed return value means invalid PE config
390  * address.
391  */
392 static int pseries_eeh_get_pe_addr(struct eeh_pe *pe)
393 {
394 	int ret = 0;
395 	int rets[3];
396 
397 	if (ibm_get_config_addr_info2 != RTAS_UNKNOWN_SERVICE) {
398 		/*
399 		 * First of all, we need to make sure there has one PE
400 		 * associated with the device. Otherwise, PE address is
401 		 * meaningless.
402 		 */
403 		ret = rtas_call(ibm_get_config_addr_info2, 4, 2, rets,
404 				pe->config_addr, BUID_HI(pe->phb->buid),
405 				BUID_LO(pe->phb->buid), 1);
406 		if (ret || (rets[0] == 0))
407 			return 0;
408 
409 		/* Retrieve the associated PE config address */
410 		ret = rtas_call(ibm_get_config_addr_info2, 4, 2, rets,
411 				pe->config_addr, BUID_HI(pe->phb->buid),
412 				BUID_LO(pe->phb->buid), 0);
413 		if (ret) {
414 			pr_warn("%s: Failed to get address for PHB#%x-PE#%x\n",
415 				__func__, pe->phb->global_number, pe->config_addr);
416 			return 0;
417 		}
418 
419 		return rets[0];
420 	}
421 
422 	if (ibm_get_config_addr_info != RTAS_UNKNOWN_SERVICE) {
423 		ret = rtas_call(ibm_get_config_addr_info, 4, 2, rets,
424 				pe->config_addr, BUID_HI(pe->phb->buid),
425 				BUID_LO(pe->phb->buid), 0);
426 		if (ret) {
427 			pr_warn("%s: Failed to get address for PHB#%x-PE#%x\n",
428 				__func__, pe->phb->global_number, pe->config_addr);
429 			return 0;
430 		}
431 
432 		return rets[0];
433 	}
434 
435 	return ret;
436 }
437 
438 /**
439  * pseries_eeh_get_state - Retrieve PE state
440  * @pe: EEH PE
441  * @delay: suggested time to wait if state is unavailable
442  *
443  * Retrieve the state of the specified PE. On RTAS compliant
444  * pseries platform, there already has one dedicated RTAS function
445  * for the purpose. It's notable that the associated PE config address
446  * might be ready when calling the function. Therefore, endeavour to
447  * use the PE config address if possible. Further more, there're 2
448  * RTAS calls for the purpose, we need to try the new one and back
449  * to the old one if the new one couldn't work properly.
450  */
451 static int pseries_eeh_get_state(struct eeh_pe *pe, int *delay)
452 {
453 	int config_addr;
454 	int ret;
455 	int rets[4];
456 	int result;
457 
458 	/* Figure out PE config address if possible */
459 	config_addr = pe->config_addr;
460 	if (pe->addr)
461 		config_addr = pe->addr;
462 
463 	if (ibm_read_slot_reset_state2 != RTAS_UNKNOWN_SERVICE) {
464 		ret = rtas_call(ibm_read_slot_reset_state2, 3, 4, rets,
465 				config_addr, BUID_HI(pe->phb->buid),
466 				BUID_LO(pe->phb->buid));
467 	} else if (ibm_read_slot_reset_state != RTAS_UNKNOWN_SERVICE) {
468 		/* Fake PE unavailable info */
469 		rets[2] = 0;
470 		ret = rtas_call(ibm_read_slot_reset_state, 3, 3, rets,
471 				config_addr, BUID_HI(pe->phb->buid),
472 				BUID_LO(pe->phb->buid));
473 	} else {
474 		return EEH_STATE_NOT_SUPPORT;
475 	}
476 
477 	if (ret)
478 		return ret;
479 
480 	/* Parse the result out */
481 	if (!rets[1])
482 		return EEH_STATE_NOT_SUPPORT;
483 
484 	switch(rets[0]) {
485 	case 0:
486 		result = EEH_STATE_MMIO_ACTIVE |
487 			 EEH_STATE_DMA_ACTIVE;
488 		break;
489 	case 1:
490 		result = EEH_STATE_RESET_ACTIVE |
491 			 EEH_STATE_MMIO_ACTIVE  |
492 			 EEH_STATE_DMA_ACTIVE;
493 		break;
494 	case 2:
495 		result = 0;
496 		break;
497 	case 4:
498 		result = EEH_STATE_MMIO_ENABLED;
499 		break;
500 	case 5:
501 		if (rets[2]) {
502 			if (delay)
503 				*delay = rets[2];
504 			result = EEH_STATE_UNAVAILABLE;
505 		} else {
506 			result = EEH_STATE_NOT_SUPPORT;
507 		}
508 		break;
509 	default:
510 		result = EEH_STATE_NOT_SUPPORT;
511 	}
512 
513 	return result;
514 }
515 
516 /**
517  * pseries_eeh_reset - Reset the specified PE
518  * @pe: EEH PE
519  * @option: reset option
520  *
521  * Reset the specified PE
522  */
523 static int pseries_eeh_reset(struct eeh_pe *pe, int option)
524 {
525 	int config_addr;
526 	int ret;
527 
528 	/* Figure out PE address */
529 	config_addr = pe->config_addr;
530 	if (pe->addr)
531 		config_addr = pe->addr;
532 
533 	/* Reset PE through RTAS call */
534 	ret = rtas_call(ibm_set_slot_reset, 4, 1, NULL,
535 			config_addr, BUID_HI(pe->phb->buid),
536 			BUID_LO(pe->phb->buid), option);
537 
538 	/* If fundamental-reset not supported, try hot-reset */
539 	if (option == EEH_RESET_FUNDAMENTAL &&
540 	    ret == -8) {
541 		option = EEH_RESET_HOT;
542 		ret = rtas_call(ibm_set_slot_reset, 4, 1, NULL,
543 				config_addr, BUID_HI(pe->phb->buid),
544 				BUID_LO(pe->phb->buid), option);
545 	}
546 
547 	/* We need reset hold or settlement delay */
548 	if (option == EEH_RESET_FUNDAMENTAL ||
549 	    option == EEH_RESET_HOT)
550 		msleep(EEH_PE_RST_HOLD_TIME);
551 	else
552 		msleep(EEH_PE_RST_SETTLE_TIME);
553 
554 	return ret;
555 }
556 
557 /**
558  * pseries_eeh_get_log - Retrieve error log
559  * @pe: EEH PE
560  * @severity: temporary or permanent error log
561  * @drv_log: driver log to be combined with retrieved error log
562  * @len: length of driver log
563  *
564  * Retrieve the temporary or permanent error from the PE.
565  * Actually, the error will be retrieved through the dedicated
566  * RTAS call.
567  */
568 static int pseries_eeh_get_log(struct eeh_pe *pe, int severity, char *drv_log, unsigned long len)
569 {
570 	int config_addr;
571 	unsigned long flags;
572 	int ret;
573 
574 	spin_lock_irqsave(&slot_errbuf_lock, flags);
575 	memset(slot_errbuf, 0, eeh_error_buf_size);
576 
577 	/* Figure out the PE address */
578 	config_addr = pe->config_addr;
579 	if (pe->addr)
580 		config_addr = pe->addr;
581 
582 	ret = rtas_call(ibm_slot_error_detail, 8, 1, NULL, config_addr,
583 			BUID_HI(pe->phb->buid), BUID_LO(pe->phb->buid),
584 			virt_to_phys(drv_log), len,
585 			virt_to_phys(slot_errbuf), eeh_error_buf_size,
586 			severity);
587 	if (!ret)
588 		log_error(slot_errbuf, ERR_TYPE_RTAS_LOG, 0);
589 	spin_unlock_irqrestore(&slot_errbuf_lock, flags);
590 
591 	return ret;
592 }
593 
594 /**
595  * pseries_eeh_configure_bridge - Configure PCI bridges in the indicated PE
596  * @pe: EEH PE
597  *
598  * The function will be called to reconfigure the bridges included
599  * in the specified PE so that the mulfunctional PE would be recovered
600  * again.
601  */
602 static int pseries_eeh_configure_bridge(struct eeh_pe *pe)
603 {
604 	int config_addr;
605 	int ret;
606 	/* Waiting 0.2s maximum before skipping configuration */
607 	int max_wait = 200;
608 
609 	/* Figure out the PE address */
610 	config_addr = pe->config_addr;
611 	if (pe->addr)
612 		config_addr = pe->addr;
613 
614 	while (max_wait > 0) {
615 		ret = rtas_call(ibm_configure_pe, 3, 1, NULL,
616 				config_addr, BUID_HI(pe->phb->buid),
617 				BUID_LO(pe->phb->buid));
618 
619 		if (!ret)
620 			return ret;
621 
622 		/*
623 		 * If RTAS returns a delay value that's above 100ms, cut it
624 		 * down to 100ms in case firmware made a mistake.  For more
625 		 * on how these delay values work see rtas_busy_delay_time
626 		 */
627 		if (ret > RTAS_EXTENDED_DELAY_MIN+2 &&
628 		    ret <= RTAS_EXTENDED_DELAY_MAX)
629 			ret = RTAS_EXTENDED_DELAY_MIN+2;
630 
631 		max_wait -= rtas_busy_delay_time(ret);
632 
633 		if (max_wait < 0)
634 			break;
635 
636 		rtas_busy_delay(ret);
637 	}
638 
639 	pr_warn("%s: Unable to configure bridge PHB#%x-PE#%x (%d)\n",
640 		__func__, pe->phb->global_number, pe->addr, ret);
641 	return ret;
642 }
643 
644 /**
645  * pseries_eeh_read_config - Read PCI config space
646  * @pdn: PCI device node
647  * @where: PCI address
648  * @size: size to read
649  * @val: return value
650  *
651  * Read config space from the speicifed device
652  */
653 static int pseries_eeh_read_config(struct pci_dn *pdn, int where, int size, u32 *val)
654 {
655 	return rtas_read_config(pdn, where, size, val);
656 }
657 
658 /**
659  * pseries_eeh_write_config - Write PCI config space
660  * @pdn: PCI device node
661  * @where: PCI address
662  * @size: size to write
663  * @val: value to be written
664  *
665  * Write config space to the specified device
666  */
667 static int pseries_eeh_write_config(struct pci_dn *pdn, int where, int size, u32 val)
668 {
669 	return rtas_write_config(pdn, where, size, val);
670 }
671 
672 static int pseries_eeh_restore_config(struct pci_dn *pdn)
673 {
674 	struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
675 	s64 ret = 0;
676 
677 	if (!edev)
678 		return -EEXIST;
679 
680 	/*
681 	 * FIXME: The MPS, error routing rules, timeout setting are worthy
682 	 * to be exported by firmware in extendible way.
683 	 */
684 	if (edev->physfn)
685 		ret = eeh_restore_vf_config(pdn);
686 
687 	if (ret) {
688 		pr_warn("%s: Can't reinit PCI dev 0x%x (%lld)\n",
689 			__func__, edev->pe_config_addr, ret);
690 		return -EIO;
691 	}
692 
693 	return ret;
694 }
695 
696 #ifdef CONFIG_PCI_IOV
697 int pseries_send_allow_unfreeze(struct pci_dn *pdn,
698 				u16 *vf_pe_array, int cur_vfs)
699 {
700 	int rc;
701 	int ibm_allow_unfreeze = rtas_token("ibm,open-sriov-allow-unfreeze");
702 	unsigned long buid, addr;
703 
704 	addr = rtas_config_addr(pdn->busno, pdn->devfn, 0);
705 	buid = pdn->phb->buid;
706 	spin_lock(&rtas_data_buf_lock);
707 	memcpy(rtas_data_buf, vf_pe_array, RTAS_DATA_BUF_SIZE);
708 	rc = rtas_call(ibm_allow_unfreeze, 5, 1, NULL,
709 		       addr,
710 		       BUID_HI(buid),
711 		       BUID_LO(buid),
712 		       rtas_data_buf, cur_vfs * sizeof(u16));
713 	spin_unlock(&rtas_data_buf_lock);
714 	if (rc)
715 		pr_warn("%s: Failed to allow unfreeze for PHB#%x-PE#%lx, rc=%x\n",
716 			__func__,
717 			pdn->phb->global_number, addr, rc);
718 	return rc;
719 }
720 
721 static int pseries_call_allow_unfreeze(struct eeh_dev *edev)
722 {
723 	struct pci_dn *pdn, *tmp, *parent, *physfn_pdn;
724 	int cur_vfs = 0, rc = 0, vf_index, bus, devfn;
725 	u16 *vf_pe_array;
726 
727 	vf_pe_array = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
728 	if (!vf_pe_array)
729 		return -ENOMEM;
730 	if (pci_num_vf(edev->physfn ? edev->physfn : edev->pdev)) {
731 		if (edev->pdev->is_physfn) {
732 			cur_vfs = pci_num_vf(edev->pdev);
733 			pdn = eeh_dev_to_pdn(edev);
734 			parent = pdn->parent;
735 			for (vf_index = 0; vf_index < cur_vfs; vf_index++)
736 				vf_pe_array[vf_index] =
737 					cpu_to_be16(pdn->pe_num_map[vf_index]);
738 			rc = pseries_send_allow_unfreeze(pdn, vf_pe_array,
739 							 cur_vfs);
740 			pdn->last_allow_rc = rc;
741 			for (vf_index = 0; vf_index < cur_vfs; vf_index++) {
742 				list_for_each_entry_safe(pdn, tmp,
743 							 &parent->child_list,
744 							 list) {
745 					bus = pci_iov_virtfn_bus(edev->pdev,
746 								 vf_index);
747 					devfn = pci_iov_virtfn_devfn(edev->pdev,
748 								     vf_index);
749 					if (pdn->busno != bus ||
750 					    pdn->devfn != devfn)
751 						continue;
752 					pdn->last_allow_rc = rc;
753 				}
754 			}
755 		} else {
756 			pdn = pci_get_pdn(edev->pdev);
757 			vf_pe_array[0] = cpu_to_be16(pdn->pe_number);
758 			physfn_pdn = pci_get_pdn(edev->physfn);
759 			rc = pseries_send_allow_unfreeze(physfn_pdn,
760 							 vf_pe_array, 1);
761 			pdn->last_allow_rc = rc;
762 		}
763 	}
764 
765 	kfree(vf_pe_array);
766 	return rc;
767 }
768 
769 static int pseries_notify_resume(struct pci_dn *pdn)
770 {
771 	struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
772 
773 	if (!edev)
774 		return -EEXIST;
775 
776 	if (rtas_token("ibm,open-sriov-allow-unfreeze")
777 	    == RTAS_UNKNOWN_SERVICE)
778 		return -EINVAL;
779 
780 	if (edev->pdev->is_physfn || edev->pdev->is_virtfn)
781 		return pseries_call_allow_unfreeze(edev);
782 
783 	return 0;
784 }
785 #endif
786 
787 static struct eeh_ops pseries_eeh_ops = {
788 	.name			= "pseries",
789 	.init			= pseries_eeh_init,
790 	.probe			= pseries_eeh_probe,
791 	.set_option		= pseries_eeh_set_option,
792 	.get_pe_addr		= pseries_eeh_get_pe_addr,
793 	.get_state		= pseries_eeh_get_state,
794 	.reset			= pseries_eeh_reset,
795 	.get_log		= pseries_eeh_get_log,
796 	.configure_bridge       = pseries_eeh_configure_bridge,
797 	.err_inject		= NULL,
798 	.read_config		= pseries_eeh_read_config,
799 	.write_config		= pseries_eeh_write_config,
800 	.next_error		= NULL,
801 	.restore_config		= pseries_eeh_restore_config,
802 #ifdef CONFIG_PCI_IOV
803 	.notify_resume		= pseries_notify_resume
804 #endif
805 };
806 
807 /**
808  * eeh_pseries_init - Register platform dependent EEH operations
809  *
810  * EEH initialization on pseries platform. This function should be
811  * called before any EEH related functions.
812  */
813 static int __init eeh_pseries_init(void)
814 {
815 	int ret;
816 
817 	ret = eeh_ops_register(&pseries_eeh_ops);
818 	if (!ret)
819 		pr_info("EEH: pSeries platform initialized\n");
820 	else
821 		pr_info("EEH: pSeries platform initialization failure (%d)\n",
822 			ret);
823 
824 	return ret;
825 }
826 machine_early_initcall(pseries, eeh_pseries_init);
827