xref: /openbmc/qemu/hw/watchdog/spapr_watchdog.c (revision 988f2442)
1 /*
2  * This library is free software; you can redistribute it and/or
3  * modify it under the terms of the GNU Lesser General Public
4  * License as published by the Free Software Foundation; either
5  * version 2.1 of the License, or (at your option) any later version.
6  *
7  * This library is distributed in the hope that it will be useful,
8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
10  * Lesser General Public License for more details.
11  *
12  * You should have received a copy of the GNU Lesser General Public
13  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
14  */
15 
16 #include "qemu/osdep.h"
17 #include "qapi/error.h"
18 #include "target/ppc/cpu.h"
19 #include "migration/vmstate.h"
20 #include "trace.h"
21 
22 #include "hw/ppc/spapr.h"
23 
24 #define FIELD_BE(reg, field, start, len) \
25     FIELD(reg, field, 64 - (start + len), len)
26 
27 /*
28  * Bits 47: "leaveOtherWatchdogsRunningOnTimeout", specified on
29  * the "Start watchdog" operation,
30  * 0 - stop out-standing watchdogs on timeout,
31  * 1 - leave outstanding watchdogs running on timeout
32  */
33 FIELD_BE(PSERIES_WDTF, LEAVE_OTHER, 47, 1)
34 
35 /*    Bits 48-55: "operation" */
36 FIELD_BE(PSERIES_WDTF, OP, 48, 8)
37 #define PSERIES_WDTF_OP_START           0x1
38 #define PSERIES_WDTF_OP_STOP            0x2
39 #define PSERIES_WDTF_OP_QUERY           0x3
40 #define PSERIES_WDTF_OP_QUERY_LPM       0x4
41 
42 /*    Bits 56-63: "timeoutAction" */
43 FIELD_BE(PSERIES_WDTF, ACTION, 56, 8)
44 #define PSERIES_WDTF_ACTION_HARD_POWER_OFF  0x1
45 #define PSERIES_WDTF_ACTION_HARD_RESTART    0x2
46 #define PSERIES_WDTF_ACTION_DUMP_RESTART    0x3
47 
48 FIELD_BE(PSERIES_WDTF, RESERVED, 0, 47)
49 
50 /* Special watchdogNumber for the "stop all watchdogs" operation */
51 #define PSERIES_WDT_STOP_ALL            ((uint64_t)~0)
52 
53 /*
54  * For the "Query watchdog capabilities" operation, a uint64 structure
55  * defined as:
56  * Bits 0-15: The minimum supported timeout in milliseconds
57  * Bits 16-31: The number of watchdogs supported
58  * Bits 32-63: Reserved
59  */
60 FIELD_BE(PSERIES_WDTQ, MIN_TIMEOUT, 0, 16)
61 FIELD_BE(PSERIES_WDTQ, NUM, 16, 16)
62 
63 /*
64  * For the "Query watchdog LPM requirement" operation:
65  * 1 = The given "watchdogNumber" must be stopped prior to suspending
66  * 2 = The given "watchdogNumber" does not have to be stopped prior to
67  * suspending
68  */
69 #define PSERIES_WDTQL_STOPPED               1
70 #define PSERIES_WDTQL_QUERY_NOT_STOPPED     2
71 
72 #define WDT_MIN_TIMEOUT 1 /* 1ms */
73 
74 static target_ulong watchdog_stop(unsigned watchdogNumber, SpaprWatchdog *w)
75 {
76     target_ulong ret = H_NOOP;
77 
78     if (timer_pending(&w->timer)) {
79         timer_del(&w->timer);
80         ret = H_SUCCESS;
81     }
82     trace_spapr_watchdog_stop(watchdogNumber, ret);
83 
84     return ret;
85 }
86 
87 static target_ulong watchdog_stop_all(SpaprMachineState *spapr)
88 {
89     target_ulong ret = H_NOOP;
90     int i;
91 
92     for (i = 1; i <= ARRAY_SIZE(spapr->wds); ++i) {
93         target_ulong r = watchdog_stop(i, &spapr->wds[i - 1]);
94 
95         if (r != H_NOOP && r != H_SUCCESS) {
96             ret = r;
97         }
98     }
99 
100     return ret;
101 }
102 
103 static void watchdog_expired(void *pw)
104 {
105     SpaprWatchdog *w = pw;
106     CPUState *cs;
107     SpaprMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
108     unsigned num = w - spapr->wds;
109 
110     g_assert(num < ARRAY_SIZE(spapr->wds));
111     trace_spapr_watchdog_expired(num, w->action);
112     switch (w->action) {
113     case PSERIES_WDTF_ACTION_HARD_POWER_OFF:
114         qemu_system_vmstop_request(RUN_STATE_SHUTDOWN);
115         break;
116     case PSERIES_WDTF_ACTION_HARD_RESTART:
117         qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
118         break;
119     case PSERIES_WDTF_ACTION_DUMP_RESTART:
120         CPU_FOREACH(cs) {
121             async_run_on_cpu(cs, spapr_do_system_reset_on_cpu, RUN_ON_CPU_NULL);
122         }
123         break;
124     }
125     if (!w->leave_others) {
126         watchdog_stop_all(spapr);
127     }
128 }
129 
130 static target_ulong h_watchdog(PowerPCCPU *cpu,
131                                SpaprMachineState *spapr,
132                                target_ulong opcode, target_ulong *args)
133 {
134     target_ulong ret = H_SUCCESS;
135     target_ulong flags = args[0];
136     target_ulong watchdogNumber = args[1]; /* 1-Based per PAPR */
137     target_ulong timeoutInMs = args[2];
138     unsigned operation = FIELD_EX64(flags, PSERIES_WDTF, OP);
139     unsigned timeoutAction = FIELD_EX64(flags, PSERIES_WDTF, ACTION);
140     SpaprWatchdog *w;
141 
142     if (FIELD_EX64(flags, PSERIES_WDTF, RESERVED)) {
143         return H_PARAMETER;
144     }
145 
146     switch (operation) {
147     case PSERIES_WDTF_OP_START:
148         if (watchdogNumber > ARRAY_SIZE(spapr->wds)) {
149             return H_P2;
150         }
151         if (timeoutInMs <= WDT_MIN_TIMEOUT) {
152             return H_P3;
153         }
154 
155         w = &spapr->wds[watchdogNumber - 1];
156         switch (timeoutAction) {
157         case PSERIES_WDTF_ACTION_HARD_POWER_OFF:
158         case PSERIES_WDTF_ACTION_HARD_RESTART:
159         case PSERIES_WDTF_ACTION_DUMP_RESTART:
160             w->action = timeoutAction;
161             break;
162         default:
163             return H_PARAMETER;
164         }
165         w->leave_others = FIELD_EX64(flags, PSERIES_WDTF, LEAVE_OTHER);
166         timer_mod(&w->timer,
167                   qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + timeoutInMs);
168         trace_spapr_watchdog_start(flags, watchdogNumber, timeoutInMs);
169         break;
170     case PSERIES_WDTF_OP_STOP:
171         if (watchdogNumber == PSERIES_WDT_STOP_ALL) {
172             ret = watchdog_stop_all(spapr);
173         } else if (watchdogNumber <= ARRAY_SIZE(spapr->wds)) {
174             ret = watchdog_stop(watchdogNumber,
175                                 &spapr->wds[watchdogNumber - 1]);
176         } else {
177             return H_P2;
178         }
179         break;
180     case PSERIES_WDTF_OP_QUERY:
181         args[0] = FIELD_DP64(0, PSERIES_WDTQ, MIN_TIMEOUT, WDT_MIN_TIMEOUT);
182         args[0] = FIELD_DP64(args[0], PSERIES_WDTQ, NUM,
183                              ARRAY_SIZE(spapr->wds));
184         trace_spapr_watchdog_query(args[0]);
185         break;
186     case PSERIES_WDTF_OP_QUERY_LPM:
187         if (watchdogNumber > ARRAY_SIZE(spapr->wds)) {
188             return H_P2;
189         }
190         args[0] = PSERIES_WDTQL_QUERY_NOT_STOPPED;
191         trace_spapr_watchdog_query_lpm(args[0]);
192         break;
193     default:
194         return H_PARAMETER;
195     }
196 
197     return ret;
198 }
199 
200 void spapr_watchdog_init(SpaprMachineState *spapr)
201 {
202     int i;
203 
204     for (i = 0; i < ARRAY_SIZE(spapr->wds); ++i) {
205         char name[16];
206         SpaprWatchdog *w = &spapr->wds[i];
207 
208         snprintf(name, sizeof(name) - 1, "wdt%d", i + 1);
209         object_initialize_child_with_props(OBJECT(spapr), name, w,
210                                            sizeof(SpaprWatchdog),
211                                            TYPE_SPAPR_WDT,
212                                            &error_fatal, NULL);
213         qdev_realize(DEVICE(w), NULL, &error_fatal);
214     }
215 }
216 
217 static bool watchdog_needed(void *opaque)
218 {
219     SpaprWatchdog *w = opaque;
220 
221     return timer_pending(&w->timer);
222 }
223 
224 static const VMStateDescription vmstate_wdt = {
225     .name = "spapr_watchdog",
226     .version_id = 1,
227     .minimum_version_id = 1,
228     .needed = watchdog_needed,
229     .fields = (const VMStateField[]) {
230         VMSTATE_TIMER(timer, SpaprWatchdog),
231         VMSTATE_UINT8(action, SpaprWatchdog),
232         VMSTATE_UINT8(leave_others, SpaprWatchdog),
233         VMSTATE_END_OF_LIST()
234     }
235 };
236 
237 static void spapr_wdt_realize(DeviceState *dev, Error **errp)
238 {
239     SpaprWatchdog *w = SPAPR_WDT(dev);
240     Object *o = OBJECT(dev);
241 
242     timer_init_ms(&w->timer, QEMU_CLOCK_VIRTUAL, watchdog_expired, w);
243 
244     object_property_add_uint64_ptr(o, "expire",
245                                    (uint64_t *)&w->timer.expire_time,
246                                    OBJ_PROP_FLAG_READ);
247     object_property_add_uint8_ptr(o, "action", &w->action, OBJ_PROP_FLAG_READ);
248     object_property_add_uint8_ptr(o, "leaveOtherWatchdogsRunningOnTimeout",
249                                   &w->leave_others, OBJ_PROP_FLAG_READ);
250 }
251 
252 static void spapr_wdt_class_init(ObjectClass *oc, void *data)
253 {
254     DeviceClass *dc = DEVICE_CLASS(oc);
255 
256     dc->realize = spapr_wdt_realize;
257     dc->vmsd = &vmstate_wdt;
258     dc->user_creatable = false;
259 }
260 
261 static const TypeInfo spapr_wdt_info = {
262     .name          = TYPE_SPAPR_WDT,
263     .parent        = TYPE_DEVICE,
264     .instance_size = sizeof(SpaprWatchdog),
265     .class_init    = spapr_wdt_class_init,
266 };
267 
268 static void spapr_watchdog_register_types(void)
269 {
270     spapr_register_hypercall(H_WATCHDOG, h_watchdog);
271     type_register_static(&spapr_wdt_info);
272 }
273 
274 type_init(spapr_watchdog_register_types)
275