This source file includes following definitions.
- timer_handler
- itimer_shutdown
- itimer_set_periodic
- itimer_next_event
- itimer_one_shot
- um_timer
- timer_read
- um_timer_setup
- read_persistent_clock64
- time_init
- calibrate_delay_is_known
- setup_time_travel
- setup_time_travel_start
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9 #include <linux/clockchips.h>
10 #include <linux/init.h>
11 #include <linux/interrupt.h>
12 #include <linux/jiffies.h>
13 #include <linux/mm.h>
14 #include <linux/sched.h>
15 #include <linux/spinlock.h>
16 #include <linux/threads.h>
17 #include <asm/irq.h>
18 #include <asm/param.h>
19 #include <kern_util.h>
20 #include <os.h>
21 #include <timer-internal.h>
22 #include <shared/init.h>
23
24 #ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
25 enum time_travel_mode time_travel_mode;
26 unsigned long long time_travel_time;
27 enum time_travel_timer_mode time_travel_timer_mode;
28 unsigned long long time_travel_timer_expiry;
29 unsigned long long time_travel_timer_interval;
30
31 static bool time_travel_start_set;
32 static unsigned long long time_travel_start;
33 #else
34 #define time_travel_start_set 0
35 #define time_travel_start 0
36 #endif
37
38 void timer_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
39 {
40 unsigned long flags;
41
42
43
44
45
46
47
48
49
50 if (time_travel_mode == TT_MODE_BASIC)
51 time_travel_set_time(time_travel_timer_expiry);
52
53 local_irq_save(flags);
54 do_IRQ(TIMER_IRQ, regs);
55 local_irq_restore(flags);
56 }
57
58 static int itimer_shutdown(struct clock_event_device *evt)
59 {
60 if (time_travel_mode != TT_MODE_OFF)
61 time_travel_set_timer_mode(TT_TMR_DISABLED);
62
63 if (time_travel_mode != TT_MODE_INFCPU)
64 os_timer_disable();
65
66 return 0;
67 }
68
69 static int itimer_set_periodic(struct clock_event_device *evt)
70 {
71 unsigned long long interval = NSEC_PER_SEC / HZ;
72
73 if (time_travel_mode != TT_MODE_OFF) {
74 time_travel_set_timer_mode(TT_TMR_PERIODIC);
75 time_travel_set_timer_expiry(time_travel_time + interval);
76 time_travel_set_timer_interval(interval);
77 }
78
79 if (time_travel_mode != TT_MODE_INFCPU)
80 os_timer_set_interval(interval);
81
82 return 0;
83 }
84
85 static int itimer_next_event(unsigned long delta,
86 struct clock_event_device *evt)
87 {
88 delta += 1;
89
90 if (time_travel_mode != TT_MODE_OFF) {
91 time_travel_set_timer_mode(TT_TMR_ONESHOT);
92 time_travel_set_timer_expiry(time_travel_time + delta);
93 }
94
95 if (time_travel_mode != TT_MODE_INFCPU)
96 return os_timer_one_shot(delta);
97
98 return 0;
99 }
100
101 static int itimer_one_shot(struct clock_event_device *evt)
102 {
103 return itimer_next_event(0, evt);
104 }
105
106 static struct clock_event_device timer_clockevent = {
107 .name = "posix-timer",
108 .rating = 250,
109 .cpumask = cpu_possible_mask,
110 .features = CLOCK_EVT_FEAT_PERIODIC |
111 CLOCK_EVT_FEAT_ONESHOT,
112 .set_state_shutdown = itimer_shutdown,
113 .set_state_periodic = itimer_set_periodic,
114 .set_state_oneshot = itimer_one_shot,
115 .set_next_event = itimer_next_event,
116 .shift = 0,
117 .max_delta_ns = 0xffffffff,
118 .max_delta_ticks = 0xffffffff,
119 .min_delta_ns = TIMER_MIN_DELTA,
120 .min_delta_ticks = TIMER_MIN_DELTA,
121 .irq = 0,
122 .mult = 1,
123 };
124
125 static irqreturn_t um_timer(int irq, void *dev)
126 {
127 if (get_current()->mm != NULL)
128 {
129
130 os_alarm_process(get_current()->mm->context.id.u.pid);
131 }
132
133 (*timer_clockevent.event_handler)(&timer_clockevent);
134
135 return IRQ_HANDLED;
136 }
137
138 static u64 timer_read(struct clocksource *cs)
139 {
140 if (time_travel_mode != TT_MODE_OFF) {
141
142
143
144
145
146
147 time_travel_set_time(time_travel_time + TIMER_MULTIPLIER);
148 return time_travel_time / TIMER_MULTIPLIER;
149 }
150
151 return os_nsecs() / TIMER_MULTIPLIER;
152 }
153
154 static struct clocksource timer_clocksource = {
155 .name = "timer",
156 .rating = 300,
157 .read = timer_read,
158 .mask = CLOCKSOURCE_MASK(64),
159 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
160 };
161
162 static void __init um_timer_setup(void)
163 {
164 int err;
165
166 err = request_irq(TIMER_IRQ, um_timer, IRQF_TIMER, "hr timer", NULL);
167 if (err != 0)
168 printk(KERN_ERR "register_timer : request_irq failed - "
169 "errno = %d\n", -err);
170
171 err = os_timer_create();
172 if (err != 0) {
173 printk(KERN_ERR "creation of timer failed - errno = %d\n", -err);
174 return;
175 }
176
177 err = clocksource_register_hz(&timer_clocksource, NSEC_PER_SEC/TIMER_MULTIPLIER);
178 if (err) {
179 printk(KERN_ERR "clocksource_register_hz returned %d\n", err);
180 return;
181 }
182 clockevents_register_device(&timer_clockevent);
183 }
184
185 void read_persistent_clock64(struct timespec64 *ts)
186 {
187 long long nsecs;
188
189 if (time_travel_start_set)
190 nsecs = time_travel_start + time_travel_time;
191 else
192 nsecs = os_persistent_clock_emulation();
193
194 set_normalized_timespec64(ts, nsecs / NSEC_PER_SEC,
195 nsecs % NSEC_PER_SEC);
196 }
197
198 void __init time_init(void)
199 {
200 timer_set_signal_handler();
201 late_time_init = um_timer_setup;
202 }
203
204 #ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
205 unsigned long calibrate_delay_is_known(void)
206 {
207 if (time_travel_mode == TT_MODE_INFCPU)
208 return 1;
209 return 0;
210 }
211
212 int setup_time_travel(char *str)
213 {
214 if (strcmp(str, "=inf-cpu") == 0) {
215 time_travel_mode = TT_MODE_INFCPU;
216 timer_clockevent.name = "time-travel-timer-infcpu";
217 timer_clocksource.name = "time-travel-clock";
218 return 1;
219 }
220
221 if (!*str) {
222 time_travel_mode = TT_MODE_BASIC;
223 timer_clockevent.name = "time-travel-timer";
224 timer_clocksource.name = "time-travel-clock";
225 return 1;
226 }
227
228 return -EINVAL;
229 }
230
231 __setup("time-travel", setup_time_travel);
232 __uml_help(setup_time_travel,
233 "time-travel\n"
234 "This option just enables basic time travel mode, in which the clock/timers\n"
235 "inside the UML instance skip forward when there's nothing to do, rather than\n"
236 "waiting for real time to elapse. However, instance CPU speed is limited by\n"
237 "the real CPU speed, so e.g. a 10ms timer will always fire after ~10ms wall\n"
238 "clock (but quicker when there's nothing to do).\n"
239 "\n"
240 "time-travel=inf-cpu\n"
241 "This enables time travel mode with infinite processing power, in which there\n"
242 "are no wall clock timers, and any CPU processing happens - as seen from the\n"
243 "guest - instantly. This can be useful for accurate simulation regardless of\n"
244 "debug overhead, physical CPU speed, etc. but is somewhat dangerous as it can\n"
245 "easily lead to getting stuck (e.g. if anything in the system busy loops).\n");
246
247 int setup_time_travel_start(char *str)
248 {
249 int err;
250
251 err = kstrtoull(str, 0, &time_travel_start);
252 if (err)
253 return err;
254
255 time_travel_start_set = 1;
256 return 1;
257 }
258
259 __setup("time-travel-start", setup_time_travel_start);
260 __uml_help(setup_time_travel_start,
261 "time-travel-start=<seconds>\n"
262 "Configure the UML instance's wall clock to start at this value rather than\n"
263 "the host's wall clock at the time of UML boot.\n");
264 #endif