2 * Machine check exception handling.
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18 * Copyright 2013 IBM Corporation
19 * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
23 #define pr_fmt(fmt) "mce: " fmt
25 #include <linux/types.h>
26 #include <linux/ptrace.h>
27 #include <linux/percpu.h>
28 #include <linux/export.h>
29 #include <linux/irq_work.h>
32 static DEFINE_PER_CPU(int, mce_nest_count);
33 static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT], mce_event);
35 /* Queue for delayed MCE events. */
36 static DEFINE_PER_CPU(int, mce_queue_count);
37 static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT], mce_event_queue);
39 static void machine_check_process_queued_event(struct irq_work *work);
40 static struct irq_work mce_event_process_work = {
41 .func = machine_check_process_queued_event,
44 static void mce_set_error_info(struct machine_check_event *mce,
45 struct mce_error_info *mce_err)
47 mce->error_type = mce_err->error_type;
48 switch (mce_err->error_type) {
49 case MCE_ERROR_TYPE_UE:
50 mce->u.ue_error.ue_error_type = mce_err->u.ue_error_type;
52 case MCE_ERROR_TYPE_SLB:
53 mce->u.slb_error.slb_error_type = mce_err->u.slb_error_type;
55 case MCE_ERROR_TYPE_ERAT:
56 mce->u.erat_error.erat_error_type = mce_err->u.erat_error_type;
58 case MCE_ERROR_TYPE_TLB:
59 mce->u.tlb_error.tlb_error_type = mce_err->u.tlb_error_type;
61 case MCE_ERROR_TYPE_UNKNOWN:
68 * Decode and save high level MCE information into per cpu buffer which
69 * is an array of machine_check_event structure.
71 void save_mce_event(struct pt_regs *regs, long handled,
72 struct mce_error_info *mce_err,
73 uint64_t nip, uint64_t addr)
76 int index = __this_cpu_inc_return(mce_nest_count) - 1;
77 struct machine_check_event *mce = this_cpu_ptr(&mce_event[index]);
80 * Return if we don't have enough space to log mce event.
81 * mce_nest_count may go beyond MAX_MC_EVT but that's ok,
82 * the check below will stop buffer overrun.
84 if (index >= MAX_MC_EVT)
87 /* Populate generic machine check info */
88 mce->version = MCE_V1;
90 mce->srr1 = regs->msr;
91 mce->gpr3 = regs->gpr[3];
94 mce->initiator = MCE_INITIATOR_CPU;
95 /* Mark it recovered if we have handled it and MSR(RI=1). */
96 if (handled && (regs->msr & MSR_RI))
97 mce->disposition = MCE_DISPOSITION_RECOVERED;
99 mce->disposition = MCE_DISPOSITION_NOT_RECOVERED;
100 mce->severity = MCE_SEV_ERROR_SYNC;
105 * Populate the mce error_type and type-specific error_type.
107 mce_set_error_info(mce, mce_err);
112 if (mce->error_type == MCE_ERROR_TYPE_TLB) {
113 mce->u.tlb_error.effective_address_provided = true;
114 mce->u.tlb_error.effective_address = addr;
115 } else if (mce->error_type == MCE_ERROR_TYPE_SLB) {
116 mce->u.slb_error.effective_address_provided = true;
117 mce->u.slb_error.effective_address = addr;
118 } else if (mce->error_type == MCE_ERROR_TYPE_ERAT) {
119 mce->u.erat_error.effective_address_provided = true;
120 mce->u.erat_error.effective_address = addr;
121 } else if (mce->error_type == MCE_ERROR_TYPE_UE) {
122 mce->u.ue_error.effective_address_provided = true;
123 mce->u.ue_error.effective_address = addr;
130 * mce Pointer to machine_check_event structure to be filled.
131 * release Flag to indicate whether to free the event slot or not.
132 * 0 <= do not release the mce event. Caller will invoke
133 * release_mce_event() once event has been consumed.
134 * 1 <= release the slot.
139 * get_mce_event() will be called by platform specific machine check
140 * handle routine and in KVM.
141 * When we call get_mce_event(), we are still in interrupt context and
142 * preemption will not be scheduled until ret_from_expect() routine
145 int get_mce_event(struct machine_check_event *mce, bool release)
147 int index = __this_cpu_read(mce_nest_count) - 1;
148 struct machine_check_event *mc_evt;
155 /* Check if we have MCE info to process. */
156 if (index < MAX_MC_EVT) {
157 mc_evt = this_cpu_ptr(&mce_event[index]);
158 /* Copy the event structure and release the original */
165 /* Decrement the count to free the slot. */
167 __this_cpu_dec(mce_nest_count);
172 void release_mce_event(void)
174 get_mce_event(NULL, true);
178 * Queue up the MCE event which then can be handled later.
180 void machine_check_queue_event(void)
183 struct machine_check_event evt;
185 if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
188 index = __this_cpu_inc_return(mce_queue_count) - 1;
189 /* If queue is full, just return for now. */
190 if (index >= MAX_MC_EVT) {
191 __this_cpu_dec(mce_queue_count);
194 memcpy(this_cpu_ptr(&mce_event_queue[index]), &evt, sizeof(evt));
196 /* Queue irq work to process this event later. */
197 irq_work_queue(&mce_event_process_work);
201 * process pending MCE event from the mce event queue. This function will be
202 * called during syscall exit.
204 static void machine_check_process_queued_event(struct irq_work *work)
209 * For now just print it to console.
210 * TODO: log this error event to FSP or nvram.
212 while (__this_cpu_read(mce_queue_count) > 0) {
213 index = __this_cpu_read(mce_queue_count) - 1;
214 machine_check_print_event_info(
215 this_cpu_ptr(&mce_event_queue[index]));
216 __this_cpu_dec(mce_queue_count);
220 void machine_check_print_event_info(struct machine_check_event *evt)
222 const char *level, *sevstr, *subtype;
223 static const char *mc_ue_types[] = {
226 "Page table walk ifetch",
228 "Page table walk Load/Store",
230 static const char *mc_slb_types[] = {
235 static const char *mc_erat_types[] = {
240 static const char *mc_tlb_types[] = {
246 /* Print things out */
247 if (evt->version != MCE_V1) {
248 pr_err("Machine Check Exception, Unknown event version %d !\n",
252 switch (evt->severity) {
253 case MCE_SEV_NO_ERROR:
257 case MCE_SEV_WARNING:
258 level = KERN_WARNING;
261 case MCE_SEV_ERROR_SYNC:
272 printk("%s%s Machine check interrupt [%s]\n", level, sevstr,
273 evt->disposition == MCE_DISPOSITION_RECOVERED ?
274 "Recovered" : "[Not recovered");
275 printk("%s Initiator: %s\n", level,
276 evt->initiator == MCE_INITIATOR_CPU ? "CPU" : "Unknown");
277 switch (evt->error_type) {
278 case MCE_ERROR_TYPE_UE:
279 subtype = evt->u.ue_error.ue_error_type <
280 ARRAY_SIZE(mc_ue_types) ?
281 mc_ue_types[evt->u.ue_error.ue_error_type]
283 printk("%s Error type: UE [%s]\n", level, subtype);
284 if (evt->u.ue_error.effective_address_provided)
285 printk("%s Effective address: %016llx\n",
286 level, evt->u.ue_error.effective_address);
287 if (evt->u.ue_error.physical_address_provided)
288 printk("%s Physical address: %016llx\n",
289 level, evt->u.ue_error.physical_address);
291 case MCE_ERROR_TYPE_SLB:
292 subtype = evt->u.slb_error.slb_error_type <
293 ARRAY_SIZE(mc_slb_types) ?
294 mc_slb_types[evt->u.slb_error.slb_error_type]
296 printk("%s Error type: SLB [%s]\n", level, subtype);
297 if (evt->u.slb_error.effective_address_provided)
298 printk("%s Effective address: %016llx\n",
299 level, evt->u.slb_error.effective_address);
301 case MCE_ERROR_TYPE_ERAT:
302 subtype = evt->u.erat_error.erat_error_type <
303 ARRAY_SIZE(mc_erat_types) ?
304 mc_erat_types[evt->u.erat_error.erat_error_type]
306 printk("%s Error type: ERAT [%s]\n", level, subtype);
307 if (evt->u.erat_error.effective_address_provided)
308 printk("%s Effective address: %016llx\n",
309 level, evt->u.erat_error.effective_address);
311 case MCE_ERROR_TYPE_TLB:
312 subtype = evt->u.tlb_error.tlb_error_type <
313 ARRAY_SIZE(mc_tlb_types) ?
314 mc_tlb_types[evt->u.tlb_error.tlb_error_type]
316 printk("%s Error type: TLB [%s]\n", level, subtype);
317 if (evt->u.tlb_error.effective_address_provided)
318 printk("%s Effective address: %016llx\n",
319 level, evt->u.tlb_error.effective_address);
322 case MCE_ERROR_TYPE_UNKNOWN:
323 printk("%s Error type: Unknown\n", level);
328 uint64_t get_mce_fault_addr(struct machine_check_event *evt)
330 switch (evt->error_type) {
331 case MCE_ERROR_TYPE_UE:
332 if (evt->u.ue_error.effective_address_provided)
333 return evt->u.ue_error.effective_address;
335 case MCE_ERROR_TYPE_SLB:
336 if (evt->u.slb_error.effective_address_provided)
337 return evt->u.slb_error.effective_address;
339 case MCE_ERROR_TYPE_ERAT:
340 if (evt->u.erat_error.effective_address_provided)
341 return evt->u.erat_error.effective_address;
343 case MCE_ERROR_TYPE_TLB:
344 if (evt->u.tlb_error.effective_address_provided)
345 return evt->u.tlb_error.effective_address;
348 case MCE_ERROR_TYPE_UNKNOWN:
353 EXPORT_SYMBOL(get_mce_fault_addr);