1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * OPAL hypervisor Maintenance interrupt handling support in PowerNV.
4  *
5  * Copyright 2014 IBM Corporation
6  * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
7  */
8 
9 #undef DEBUG
10 
11 #include <linux/kernel.h>
12 #include <linux/init.h>
13 #include <linux/of.h>
14 #include <linux/mm.h>
15 #include <linux/slab.h>
16 
17 #include <asm/opal.h>
18 #include <asm/cputable.h>
19 #include <asm/machdep.h>
20 
21 #include "powernv.h"
22 
23 static int opal_hmi_handler_nb_init;
24 struct OpalHmiEvtNode {
25 	struct list_head list;
26 	struct OpalHMIEvent hmi_evt;
27 };
28 
29 struct xstop_reason {
30 	uint32_t xstop_reason;
31 	const char *unit_failed;
32 	const char *description;
33 };
34 
35 static LIST_HEAD(opal_hmi_evt_list);
36 static DEFINE_SPINLOCK(opal_hmi_evt_lock);
37 
38 static void print_core_checkstop_reason(const char *level,
39 					struct OpalHMIEvent *hmi_evt)
40 {
41 	int i;
42 	static const struct xstop_reason xstop_reason[] = {
43 		{ CORE_CHECKSTOP_IFU_REGFILE, "IFU",
44 				"RegFile core check stop" },
45 		{ CORE_CHECKSTOP_IFU_LOGIC, "IFU", "Logic core check stop" },
46 		{ CORE_CHECKSTOP_PC_DURING_RECOV, "PC",
47 				"Core checkstop during recovery" },
48 		{ CORE_CHECKSTOP_ISU_REGFILE, "ISU",
49 				"RegFile core check stop (mapper error)" },
50 		{ CORE_CHECKSTOP_ISU_LOGIC, "ISU", "Logic core check stop" },
51 		{ CORE_CHECKSTOP_FXU_LOGIC, "FXU", "Logic core check stop" },
52 		{ CORE_CHECKSTOP_VSU_LOGIC, "VSU", "Logic core check stop" },
53 		{ CORE_CHECKSTOP_PC_RECOV_IN_MAINT_MODE, "PC",
54 				"Recovery in maintenance mode" },
55 		{ CORE_CHECKSTOP_LSU_REGFILE, "LSU",
56 				"RegFile core check stop" },
57 		{ CORE_CHECKSTOP_PC_FWD_PROGRESS, "PC",
58 				"Forward Progress Error" },
59 		{ CORE_CHECKSTOP_LSU_LOGIC, "LSU", "Logic core check stop" },
60 		{ CORE_CHECKSTOP_PC_LOGIC, "PC", "Logic core check stop" },
61 		{ CORE_CHECKSTOP_PC_HYP_RESOURCE, "PC",
62 				"Hypervisor Resource error - core check stop" },
63 		{ CORE_CHECKSTOP_PC_HANG_RECOV_FAILED, "PC",
64 				"Hang Recovery Failed (core check stop)" },
65 		{ CORE_CHECKSTOP_PC_AMBI_HANG_DETECTED, "PC",
66 				"Ambiguous Hang Detected (unknown source)" },
67 		{ CORE_CHECKSTOP_PC_DEBUG_TRIG_ERR_INJ, "PC",
68 				"Debug Trigger Error inject" },
69 		{ CORE_CHECKSTOP_PC_SPRD_HYP_ERR_INJ, "PC",
70 				"Hypervisor check stop via SPRC/SPRD" },
71 	};
72 
73 	/* Validity check */
74 	if (!hmi_evt->u.xstop_error.xstop_reason) {
75 		printk("%s	Unknown Core check stop.\n", level);
76 		return;
77 	}
78 
79 	printk("%s	CPU PIR: %08x\n", level,
80 			be32_to_cpu(hmi_evt->u.xstop_error.u.pir));
81 	for (i = 0; i < ARRAY_SIZE(xstop_reason); i++)
82 		if (be32_to_cpu(hmi_evt->u.xstop_error.xstop_reason) &
83 					xstop_reason[i].xstop_reason)
84 			printk("%s	[Unit: %-3s] %s\n", level,
85 					xstop_reason[i].unit_failed,
86 					xstop_reason[i].description);
87 }
88 
89 static void print_nx_checkstop_reason(const char *level,
90 					struct OpalHMIEvent *hmi_evt)
91 {
92 	int i;
93 	static const struct xstop_reason xstop_reason[] = {
94 		{ NX_CHECKSTOP_SHM_INVAL_STATE_ERR, "DMA & Engine",
95 					"SHM invalid state error" },
96 		{ NX_CHECKSTOP_DMA_INVAL_STATE_ERR_1, "DMA & Engine",
97 					"DMA invalid state error bit 15" },
98 		{ NX_CHECKSTOP_DMA_INVAL_STATE_ERR_2, "DMA & Engine",
99 					"DMA invalid state error bit 16" },
100 		{ NX_CHECKSTOP_DMA_CH0_INVAL_STATE_ERR, "DMA & Engine",
101 					"Channel 0 invalid state error" },
102 		{ NX_CHECKSTOP_DMA_CH1_INVAL_STATE_ERR, "DMA & Engine",
103 					"Channel 1 invalid state error" },
104 		{ NX_CHECKSTOP_DMA_CH2_INVAL_STATE_ERR, "DMA & Engine",
105 					"Channel 2 invalid state error" },
106 		{ NX_CHECKSTOP_DMA_CH3_INVAL_STATE_ERR, "DMA & Engine",
107 					"Channel 3 invalid state error" },
108 		{ NX_CHECKSTOP_DMA_CH4_INVAL_STATE_ERR, "DMA & Engine",
109 					"Channel 4 invalid state error" },
110 		{ NX_CHECKSTOP_DMA_CH5_INVAL_STATE_ERR, "DMA & Engine",
111 					"Channel 5 invalid state error" },
112 		{ NX_CHECKSTOP_DMA_CH6_INVAL_STATE_ERR, "DMA & Engine",
113 					"Channel 6 invalid state error" },
114 		{ NX_CHECKSTOP_DMA_CH7_INVAL_STATE_ERR, "DMA & Engine",
115 					"Channel 7 invalid state error" },
116 		{ NX_CHECKSTOP_DMA_CRB_UE, "DMA & Engine",
117 					"UE error on CRB(CSB address, CCB)" },
118 		{ NX_CHECKSTOP_DMA_CRB_SUE, "DMA & Engine",
119 					"SUE error on CRB(CSB address, CCB)" },
120 		{ NX_CHECKSTOP_PBI_ISN_UE, "PowerBus Interface",
121 		"CRB Kill ISN received while holding ISN with UE error" },
122 	};
123 
124 	/* Validity check */
125 	if (!hmi_evt->u.xstop_error.xstop_reason) {
126 		printk("%s	Unknown NX check stop.\n", level);
127 		return;
128 	}
129 
130 	printk("%s	NX checkstop on CHIP ID: %x\n", level,
131 			be32_to_cpu(hmi_evt->u.xstop_error.u.chip_id));
132 	for (i = 0; i < ARRAY_SIZE(xstop_reason); i++)
133 		if (be32_to_cpu(hmi_evt->u.xstop_error.xstop_reason) &
134 					xstop_reason[i].xstop_reason)
135 			printk("%s	[Unit: %-3s] %s\n", level,
136 					xstop_reason[i].unit_failed,
137 					xstop_reason[i].description);
138 }
139 
140 static void print_npu_checkstop_reason(const char *level,
141 					struct OpalHMIEvent *hmi_evt)
142 {
143 	uint8_t reason, reason_count, i;
144 
145 	/*
146 	 * We may not have a checkstop reason on some combination of
147 	 * hardware and/or skiboot version
148 	 */
149 	if (!hmi_evt->u.xstop_error.xstop_reason) {
150 		printk("%s	NPU checkstop on chip %x\n", level,
151 			be32_to_cpu(hmi_evt->u.xstop_error.u.chip_id));
152 		return;
153 	}
154 
155 	/*
156 	 * NPU2 has 3 FIRs. Reason encoded on a byte as:
157 	 *   2 bits for the FIR number
158 	 *   6 bits for the bit number
159 	 * It may be possible to find several reasons.
160 	 *
161 	 * We don't display a specific message per FIR bit as there
162 	 * are too many and most are meaningless without the workbook
163 	 * and/or hw team help anyway.
164 	 */
165 	reason_count = sizeof(hmi_evt->u.xstop_error.xstop_reason) /
166 		sizeof(reason);
167 	for (i = 0; i < reason_count; i++) {
168 		reason = (hmi_evt->u.xstop_error.xstop_reason >> (8 * i)) & 0xFF;
169 		if (reason)
170 			printk("%s	NPU checkstop on chip %x: FIR%d bit %d is set\n",
171 				level,
172 				be32_to_cpu(hmi_evt->u.xstop_error.u.chip_id),
173 				reason >> 6, reason & 0x3F);
174 	}
175 }
176 
177 static void print_checkstop_reason(const char *level,
178 					struct OpalHMIEvent *hmi_evt)
179 {
180 	uint8_t type = hmi_evt->u.xstop_error.xstop_type;
181 	switch (type) {
182 	case CHECKSTOP_TYPE_CORE:
183 		print_core_checkstop_reason(level, hmi_evt);
184 		break;
185 	case CHECKSTOP_TYPE_NX:
186 		print_nx_checkstop_reason(level, hmi_evt);
187 		break;
188 	case CHECKSTOP_TYPE_NPU:
189 		print_npu_checkstop_reason(level, hmi_evt);
190 		break;
191 	default:
192 		printk("%s	Unknown Malfunction Alert of type %d\n",
193 		       level, type);
194 		break;
195 	}
196 }
197 
198 static void print_hmi_event_info(struct OpalHMIEvent *hmi_evt)
199 {
200 	const char *level, *sevstr, *error_info;
201 	static const char *hmi_error_types[] = {
202 		"Malfunction Alert",
203 		"Processor Recovery done",
204 		"Processor recovery occurred again",
205 		"Processor recovery occurred for masked error",
206 		"Timer facility experienced an error",
207 		"TFMR SPR is corrupted",
208 		"UPS (Uninterrupted Power System) Overflow indication",
209 		"An XSCOM operation failure",
210 		"An XSCOM operation completed",
211 		"SCOM has set a reserved FIR bit to cause recovery",
212 		"Debug trigger has set a reserved FIR bit to cause recovery",
213 		"A hypervisor resource error occurred",
214 		"CAPP recovery process is in progress",
215 	};
216 
217 	/* Print things out */
218 	if (hmi_evt->version < OpalHMIEvt_V1) {
219 		pr_err("HMI Interrupt, Unknown event version %d !\n",
220 			hmi_evt->version);
221 		return;
222 	}
223 	switch (hmi_evt->severity) {
224 	case OpalHMI_SEV_NO_ERROR:
225 		level = KERN_INFO;
226 		sevstr = "Harmless";
227 		break;
228 	case OpalHMI_SEV_WARNING:
229 		level = KERN_WARNING;
230 		sevstr = "";
231 		break;
232 	case OpalHMI_SEV_ERROR_SYNC:
233 		level = KERN_ERR;
234 		sevstr = "Severe";
235 		break;
236 	case OpalHMI_SEV_FATAL:
237 	default:
238 		level = KERN_ERR;
239 		sevstr = "Fatal";
240 		break;
241 	}
242 
243 	printk("%s%s Hypervisor Maintenance interrupt [%s]\n",
244 		level, sevstr,
245 		hmi_evt->disposition == OpalHMI_DISPOSITION_RECOVERED ?
246 		"Recovered" : "Not recovered");
247 	error_info = hmi_evt->type < ARRAY_SIZE(hmi_error_types) ?
248 			hmi_error_types[hmi_evt->type]
249 			: "Unknown";
250 	printk("%s Error detail: %s\n", level, error_info);
251 	printk("%s	HMER: %016llx\n", level, be64_to_cpu(hmi_evt->hmer));
252 	if ((hmi_evt->type == OpalHMI_ERROR_TFAC) ||
253 		(hmi_evt->type == OpalHMI_ERROR_TFMR_PARITY))
254 		printk("%s	TFMR: %016llx\n", level,
255 						be64_to_cpu(hmi_evt->tfmr));
256 
257 	if (hmi_evt->version < OpalHMIEvt_V2)
258 		return;
259 
260 	/* OpalHMIEvt_V2 and above provides reason for malfunction alert. */
261 	if (hmi_evt->type == OpalHMI_ERROR_MALFUNC_ALERT)
262 		print_checkstop_reason(level, hmi_evt);
263 }
264 
265 static void hmi_event_handler(struct work_struct *work)
266 {
267 	unsigned long flags;
268 	struct OpalHMIEvent *hmi_evt;
269 	struct OpalHmiEvtNode *msg_node;
270 	uint8_t disposition;
271 	struct opal_msg msg;
272 	int unrecoverable = 0;
273 
274 	spin_lock_irqsave(&opal_hmi_evt_lock, flags);
275 	while (!list_empty(&opal_hmi_evt_list)) {
276 		msg_node = list_entry(opal_hmi_evt_list.next,
277 					   struct OpalHmiEvtNode, list);
278 		list_del(&msg_node->list);
279 		spin_unlock_irqrestore(&opal_hmi_evt_lock, flags);
280 
281 		hmi_evt = (struct OpalHMIEvent *) &msg_node->hmi_evt;
282 		print_hmi_event_info(hmi_evt);
283 		disposition = hmi_evt->disposition;
284 		kfree(msg_node);
285 
286 		/*
287 		 * Check if HMI event has been recovered or not. If not
288 		 * then kernel can't continue, we need to panic.
289 		 * But before we do that, display all the HMI event
290 		 * available on the list and set unrecoverable flag to 1.
291 		 */
292 		if (disposition != OpalHMI_DISPOSITION_RECOVERED)
293 			unrecoverable = 1;
294 
295 		spin_lock_irqsave(&opal_hmi_evt_lock, flags);
296 	}
297 	spin_unlock_irqrestore(&opal_hmi_evt_lock, flags);
298 
299 	if (unrecoverable) {
300 		/* Pull all HMI events from OPAL before we panic. */
301 		while (opal_get_msg(__pa(&msg), sizeof(msg)) == OPAL_SUCCESS) {
302 			u32 type;
303 
304 			type = be32_to_cpu(msg.msg_type);
305 
306 			/* skip if not HMI event */
307 			if (type != OPAL_MSG_HMI_EVT)
308 				continue;
309 
310 			/* HMI event info starts from param[0] */
311 			hmi_evt = (struct OpalHMIEvent *)&msg.params[0];
312 			print_hmi_event_info(hmi_evt);
313 		}
314 
315 		pnv_platform_error_reboot(NULL, "Unrecoverable HMI exception");
316 	}
317 }
318 
319 static DECLARE_WORK(hmi_event_work, hmi_event_handler);
320 /*
321  * opal_handle_hmi_event - notifier handler that queues up HMI events
322  * to be preocessed later.
323  */
324 static int opal_handle_hmi_event(struct notifier_block *nb,
325 			  unsigned long msg_type, void *msg)
326 {
327 	unsigned long flags;
328 	struct OpalHMIEvent *hmi_evt;
329 	struct opal_msg *hmi_msg = msg;
330 	struct OpalHmiEvtNode *msg_node;
331 
332 	/* Sanity Checks */
333 	if (msg_type != OPAL_MSG_HMI_EVT)
334 		return 0;
335 
336 	/* HMI event info starts from param[0] */
337 	hmi_evt = (struct OpalHMIEvent *)&hmi_msg->params[0];
338 
339 	/* Delay the logging of HMI events to workqueue. */
340 	msg_node = kzalloc(sizeof(*msg_node), GFP_ATOMIC);
341 	if (!msg_node) {
342 		pr_err("HMI: out of memory, Opal message event not handled\n");
343 		return -ENOMEM;
344 	}
345 	memcpy(&msg_node->hmi_evt, hmi_evt, sizeof(*hmi_evt));
346 
347 	spin_lock_irqsave(&opal_hmi_evt_lock, flags);
348 	list_add(&msg_node->list, &opal_hmi_evt_list);
349 	spin_unlock_irqrestore(&opal_hmi_evt_lock, flags);
350 
351 	schedule_work(&hmi_event_work);
352 	return 0;
353 }
354 
355 static struct notifier_block opal_hmi_handler_nb = {
356 	.notifier_call	= opal_handle_hmi_event,
357 	.next		= NULL,
358 	.priority	= 0,
359 };
360 
361 int __init opal_hmi_handler_init(void)
362 {
363 	int ret;
364 
365 	if (!opal_hmi_handler_nb_init) {
366 		ret = opal_message_notifier_register(
367 				OPAL_MSG_HMI_EVT, &opal_hmi_handler_nb);
368 		if (ret) {
369 			pr_err("%s: Can't register OPAL event notifier (%d)\n",
370 			       __func__, ret);
371 			return ret;
372 		}
373 		opal_hmi_handler_nb_init = 1;
374 	}
375 	return 0;
376 }
377