Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
15c84731 JF |
2 | /* |
3 | * Xen time implementation. | |
4 | * | |
5 | * This is implemented in terms of a clocksource driver which uses | |
6 | * the hypervisor clock as a nanosecond timebase, and a clockevent | |
7 | * driver which uses the hypervisor's timer mechanism. | |
8 | * | |
9 | * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007 | |
10 | */ | |
11 | #include <linux/kernel.h> | |
12 | #include <linux/interrupt.h> | |
13 | #include <linux/clocksource.h> | |
14 | #include <linux/clockchips.h> | |
5a0e3ad6 | 15 | #include <linux/gfp.h> |
c9d76a24 | 16 | #include <linux/slab.h> |
5584880e | 17 | #include <linux/pvclock_gtod.h> |
76096863 | 18 | #include <linux/timekeeper_internal.h> |
15c84731 | 19 | |
1c7b67f7 | 20 | #include <asm/pvclock.h> |
15c84731 JF |
21 | #include <asm/xen/hypervisor.h> |
22 | #include <asm/xen/hypercall.h> | |
23 | ||
24 | #include <xen/events.h> | |
409771d2 | 25 | #include <xen/features.h> |
15c84731 JF |
26 | #include <xen/interface/xen.h> |
27 | #include <xen/interface/vcpu.h> | |
28 | ||
29 | #include "xen-ops.h" | |
30 | ||
2ec16bc0 | 31 | /* Minimum amount of time until next clock event fires */ |
15c84731 | 32 | #define TIMER_SLOP 100000 |
f91a8b44 | 33 | |
38669ba2 PT |
34 | static u64 xen_sched_clock_offset __read_mostly; |
35 | ||
e93ef949 | 36 | /* Get the TSC speed from Xen */ |
409771d2 | 37 | static unsigned long xen_tsc_khz(void) |
15c84731 | 38 | { |
3807f345 | 39 | struct pvclock_vcpu_time_info *info = |
15c84731 JF |
40 | &HYPERVISOR_shared_info->vcpu_info[0].time; |
41 | ||
3807f345 | 42 | return pvclock_tsc_khz(info); |
15c84731 JF |
43 | } |
44 | ||
7b25b9cb | 45 | static u64 xen_clocksource_read(void) |
15c84731 | 46 | { |
1c7b67f7 | 47 | struct pvclock_vcpu_time_info *src; |
a5a1d1c2 | 48 | u64 ret; |
15c84731 | 49 | |
f1c39625 | 50 | preempt_disable_notrace(); |
3251f20b | 51 | src = &__this_cpu_read(xen_vcpu)->time; |
1c7b67f7 | 52 | ret = pvclock_clocksource_read(src); |
f1c39625 | 53 | preempt_enable_notrace(); |
15c84731 JF |
54 | return ret; |
55 | } | |
56 | ||
a5a1d1c2 | 57 | static u64 xen_clocksource_get_cycles(struct clocksource *cs) |
8e19608e MD |
58 | { |
59 | return xen_clocksource_read(); | |
60 | } | |
61 | ||
38669ba2 PT |
62 | static u64 xen_sched_clock(void) |
63 | { | |
64 | return xen_clocksource_read() - xen_sched_clock_offset; | |
65 | } | |
66 | ||
e27c4929 | 67 | static void xen_read_wallclock(struct timespec64 *ts) |
15c84731 | 68 | { |
1c7b67f7 GH |
69 | struct shared_info *s = HYPERVISOR_shared_info; |
70 | struct pvclock_wall_clock *wall_clock = &(s->wc); | |
71 | struct pvclock_vcpu_time_info *vcpu_time; | |
15c84731 | 72 | |
1c7b67f7 GH |
73 | vcpu_time = &get_cpu_var(xen_vcpu)->time; |
74 | pvclock_read_wallclock(wall_clock, vcpu_time, ts); | |
75 | put_cpu_var(xen_vcpu); | |
15c84731 JF |
76 | } |
77 | ||
e27c4929 | 78 | static void xen_get_wallclock(struct timespec64 *now) |
15c84731 | 79 | { |
3565184e | 80 | xen_read_wallclock(now); |
15c84731 | 81 | } |
15c84731 | 82 | |
e27c4929 | 83 | static int xen_set_wallclock(const struct timespec64 *now) |
15c84731 | 84 | { |
b5494ad8 | 85 | return -ENODEV; |
15c84731 JF |
86 | } |
87 | ||
47433b8c DV |
88 | static int xen_pvclock_gtod_notify(struct notifier_block *nb, |
89 | unsigned long was_set, void *priv) | |
15c84731 | 90 | { |
47433b8c | 91 | /* Protected by the calling core code serialization */ |
187b26a9 | 92 | static struct timespec64 next_sync; |
5584880e | 93 | |
fdb9eb9f | 94 | struct xen_platform_op op; |
76096863 SS |
95 | struct timespec64 now; |
96 | struct timekeeper *tk = priv; | |
97 | static bool settime64_supported = true; | |
98 | int ret; | |
fdb9eb9f | 99 | |
76096863 SS |
100 | now.tv_sec = tk->xtime_sec; |
101 | now.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift); | |
5584880e | 102 | |
47433b8c DV |
103 | /* |
104 | * We only take the expensive HV call when the clock was set | |
105 | * or when the 11 minutes RTC synchronization time elapsed. | |
106 | */ | |
187b26a9 | 107 | if (!was_set && timespec64_compare(&now, &next_sync) < 0) |
47433b8c | 108 | return NOTIFY_OK; |
fdb9eb9f | 109 | |
76096863 SS |
110 | again: |
111 | if (settime64_supported) { | |
112 | op.cmd = XENPF_settime64; | |
113 | op.u.settime64.mbz = 0; | |
114 | op.u.settime64.secs = now.tv_sec; | |
115 | op.u.settime64.nsecs = now.tv_nsec; | |
116 | op.u.settime64.system_time = xen_clocksource_read(); | |
117 | } else { | |
118 | op.cmd = XENPF_settime32; | |
119 | op.u.settime32.secs = now.tv_sec; | |
120 | op.u.settime32.nsecs = now.tv_nsec; | |
121 | op.u.settime32.system_time = xen_clocksource_read(); | |
122 | } | |
123 | ||
124 | ret = HYPERVISOR_platform_op(&op); | |
125 | ||
126 | if (ret == -ENOSYS && settime64_supported) { | |
127 | settime64_supported = false; | |
128 | goto again; | |
129 | } | |
130 | if (ret < 0) | |
131 | return NOTIFY_BAD; | |
fdb9eb9f | 132 | |
47433b8c DV |
133 | /* |
134 | * Move the next drift compensation time 11 minutes | |
135 | * ahead. That's emulating the sync_cmos_clock() update for | |
136 | * the hardware RTC. | |
137 | */ | |
138 | next_sync = now; | |
139 | next_sync.tv_sec += 11 * 60; | |
140 | ||
5584880e | 141 | return NOTIFY_OK; |
15c84731 JF |
142 | } |
143 | ||
5584880e DV |
144 | static struct notifier_block xen_pvclock_gtod_notifier = { |
145 | .notifier_call = xen_pvclock_gtod_notify, | |
146 | }; | |
147 | ||
eec399dd TG |
148 | static int xen_cs_enable(struct clocksource *cs) |
149 | { | |
150 | vclocks_set_used(VCLOCK_PVCLOCK); | |
151 | return 0; | |
152 | } | |
153 | ||
15c84731 | 154 | static struct clocksource xen_clocksource __read_mostly = { |
eec399dd TG |
155 | .name = "xen", |
156 | .rating = 400, | |
157 | .read = xen_clocksource_get_cycles, | |
158 | .mask = CLOCKSOURCE_MASK(64), | |
159 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, | |
160 | .enable = xen_cs_enable, | |
15c84731 JF |
161 | }; |
162 | ||
163 | /* | |
164 | Xen clockevent implementation | |
165 | ||
166 | Xen has two clockevent implementations: | |
167 | ||
168 | The old timer_op one works with all released versions of Xen prior | |
169 | to version 3.0.4. This version of the hypervisor provides a | |
170 | single-shot timer with nanosecond resolution. However, sharing the | |
171 | same event channel is a 100Hz tick which is delivered while the | |
172 | vcpu is running. We don't care about or use this tick, but it will | |
173 | cause the core time code to think the timer fired too soon, and | |
174 | will end up resetting it each time. It could be filtered, but | |
175 | doing so has complications when the ktime clocksource is not yet | |
176 | the xen clocksource (ie, at boot time). | |
177 | ||
178 | The new vcpu_op-based timer interface allows the tick timer period | |
179 | to be changed or turned off. The tick timer is not useful as a | |
180 | periodic timer because events are only delivered to running vcpus. | |
181 | The one-shot timer can report when a timeout is in the past, so | |
182 | set_next_event is capable of returning -ETIME when appropriate. | |
183 | This interface is used when available. | |
184 | */ | |
185 | ||
186 | ||
187 | /* | |
188 | Get a hypervisor absolute time. In theory we could maintain an | |
189 | offset between the kernel's time and the hypervisor's time, and | |
190 | apply that to a kernel's absolute timeout. Unfortunately the | |
191 | hypervisor and kernel times can drift even if the kernel is using | |
192 | the Xen clocksource, because ntp can warp the kernel's clocksource. | |
193 | */ | |
194 | static s64 get_abs_timeout(unsigned long delta) | |
195 | { | |
196 | return xen_clocksource_read() + delta; | |
197 | } | |
198 | ||
955381dd | 199 | static int xen_timerop_shutdown(struct clock_event_device *evt) |
15c84731 | 200 | { |
955381dd VK |
201 | /* cancel timeout */ |
202 | HYPERVISOR_set_timer_op(0); | |
203 | ||
204 | return 0; | |
15c84731 JF |
205 | } |
206 | ||
207 | static int xen_timerop_set_next_event(unsigned long delta, | |
208 | struct clock_event_device *evt) | |
209 | { | |
955381dd | 210 | WARN_ON(!clockevent_state_oneshot(evt)); |
15c84731 JF |
211 | |
212 | if (HYPERVISOR_set_timer_op(get_abs_timeout(delta)) < 0) | |
213 | BUG(); | |
214 | ||
215 | /* We may have missed the deadline, but there's no real way of | |
216 | knowing for sure. If the event was in the past, then we'll | |
217 | get an immediate interrupt. */ | |
218 | ||
219 | return 0; | |
220 | } | |
221 | ||
2ec16bc0 | 222 | static struct clock_event_device xen_timerop_clockevent __ro_after_init = { |
955381dd VK |
223 | .name = "xen", |
224 | .features = CLOCK_EVT_FEAT_ONESHOT, | |
15c84731 | 225 | |
955381dd | 226 | .max_delta_ns = 0xffffffff, |
3d18d661 | 227 | .max_delta_ticks = 0xffffffff, |
955381dd | 228 | .min_delta_ns = TIMER_SLOP, |
3d18d661 | 229 | .min_delta_ticks = TIMER_SLOP, |
15c84731 | 230 | |
955381dd VK |
231 | .mult = 1, |
232 | .shift = 0, | |
233 | .rating = 500, | |
15c84731 | 234 | |
955381dd VK |
235 | .set_state_shutdown = xen_timerop_shutdown, |
236 | .set_next_event = xen_timerop_set_next_event, | |
15c84731 JF |
237 | }; |
238 | ||
955381dd VK |
239 | static int xen_vcpuop_shutdown(struct clock_event_device *evt) |
240 | { | |
241 | int cpu = smp_processor_id(); | |
15c84731 | 242 | |
ad5475f9 VK |
243 | if (HYPERVISOR_vcpu_op(VCPUOP_stop_singleshot_timer, xen_vcpu_nr(cpu), |
244 | NULL) || | |
245 | HYPERVISOR_vcpu_op(VCPUOP_stop_periodic_timer, xen_vcpu_nr(cpu), | |
246 | NULL)) | |
955381dd | 247 | BUG(); |
15c84731 | 248 | |
955381dd VK |
249 | return 0; |
250 | } | |
251 | ||
252 | static int xen_vcpuop_set_oneshot(struct clock_event_device *evt) | |
15c84731 JF |
253 | { |
254 | int cpu = smp_processor_id(); | |
255 | ||
ad5475f9 VK |
256 | if (HYPERVISOR_vcpu_op(VCPUOP_stop_periodic_timer, xen_vcpu_nr(cpu), |
257 | NULL)) | |
955381dd VK |
258 | BUG(); |
259 | ||
260 | return 0; | |
15c84731 JF |
261 | } |
262 | ||
263 | static int xen_vcpuop_set_next_event(unsigned long delta, | |
264 | struct clock_event_device *evt) | |
265 | { | |
266 | int cpu = smp_processor_id(); | |
267 | struct vcpu_set_singleshot_timer single; | |
268 | int ret; | |
269 | ||
955381dd | 270 | WARN_ON(!clockevent_state_oneshot(evt)); |
15c84731 JF |
271 | |
272 | single.timeout_abs_ns = get_abs_timeout(delta); | |
c06b6d70 SS |
273 | /* Get an event anyway, even if the timeout is already expired */ |
274 | single.flags = 0; | |
15c84731 | 275 | |
ad5475f9 VK |
276 | ret = HYPERVISOR_vcpu_op(VCPUOP_set_singleshot_timer, xen_vcpu_nr(cpu), |
277 | &single); | |
c06b6d70 | 278 | BUG_ON(ret != 0); |
15c84731 JF |
279 | |
280 | return ret; | |
281 | } | |
282 | ||
2ec16bc0 | 283 | static struct clock_event_device xen_vcpuop_clockevent __ro_after_init = { |
15c84731 JF |
284 | .name = "xen", |
285 | .features = CLOCK_EVT_FEAT_ONESHOT, | |
286 | ||
287 | .max_delta_ns = 0xffffffff, | |
3d18d661 | 288 | .max_delta_ticks = 0xffffffff, |
15c84731 | 289 | .min_delta_ns = TIMER_SLOP, |
3d18d661 | 290 | .min_delta_ticks = TIMER_SLOP, |
15c84731 JF |
291 | |
292 | .mult = 1, | |
293 | .shift = 0, | |
294 | .rating = 500, | |
295 | ||
955381dd VK |
296 | .set_state_shutdown = xen_vcpuop_shutdown, |
297 | .set_state_oneshot = xen_vcpuop_set_oneshot, | |
15c84731 JF |
298 | .set_next_event = xen_vcpuop_set_next_event, |
299 | }; | |
300 | ||
301 | static const struct clock_event_device *xen_clockevent = | |
302 | &xen_timerop_clockevent; | |
31620a19 KRW |
303 | |
304 | struct xen_clock_event_device { | |
305 | struct clock_event_device evt; | |
7be0772d | 306 | char name[16]; |
31620a19 KRW |
307 | }; |
308 | static DEFINE_PER_CPU(struct xen_clock_event_device, xen_clock_events) = { .evt.irq = -1 }; | |
15c84731 JF |
309 | |
310 | static irqreturn_t xen_timer_interrupt(int irq, void *dev_id) | |
311 | { | |
89cbc767 | 312 | struct clock_event_device *evt = this_cpu_ptr(&xen_clock_events.evt); |
15c84731 JF |
313 | irqreturn_t ret; |
314 | ||
315 | ret = IRQ_NONE; | |
316 | if (evt->event_handler) { | |
317 | evt->event_handler(evt); | |
318 | ret = IRQ_HANDLED; | |
319 | } | |
320 | ||
321 | return ret; | |
322 | } | |
323 | ||
09e99da7 KRW |
324 | void xen_teardown_timer(int cpu) |
325 | { | |
326 | struct clock_event_device *evt; | |
09e99da7 KRW |
327 | evt = &per_cpu(xen_clock_events, cpu).evt; |
328 | ||
329 | if (evt->irq >= 0) { | |
330 | unbind_from_irqhandler(evt->irq, NULL); | |
331 | evt->irq = -1; | |
09e99da7 KRW |
332 | } |
333 | } | |
334 | ||
f87e4cac | 335 | void xen_setup_timer(int cpu) |
15c84731 | 336 | { |
7be0772d VK |
337 | struct xen_clock_event_device *xevt = &per_cpu(xen_clock_events, cpu); |
338 | struct clock_event_device *evt = &xevt->evt; | |
15c84731 JF |
339 | int irq; |
340 | ||
ef35a4e6 | 341 | WARN(evt->irq >= 0, "IRQ%d for CPU%d is already allocated\n", evt->irq, cpu); |
09e99da7 KRW |
342 | if (evt->irq >= 0) |
343 | xen_teardown_timer(cpu); | |
ef35a4e6 | 344 | |
15c84731 JF |
345 | printk(KERN_INFO "installing Xen timer for CPU %d\n", cpu); |
346 | ||
7be0772d | 347 | snprintf(xevt->name, sizeof(xevt->name), "timer%d", cpu); |
15c84731 JF |
348 | |
349 | irq = bind_virq_to_irqhandler(VIRQ_TIMER, cpu, xen_timer_interrupt, | |
9d71cee6 | 350 | IRQF_PERCPU|IRQF_NOBALANCING|IRQF_TIMER| |
8d5999df | 351 | IRQF_FORCE_RESUME|IRQF_EARLY_RESUME, |
7be0772d | 352 | xevt->name, NULL); |
8785c676 | 353 | (void)xen_set_irq_priority(irq, XEN_IRQ_PRIORITY_MAX); |
15c84731 | 354 | |
15c84731 JF |
355 | memcpy(evt, xen_clockevent, sizeof(*evt)); |
356 | ||
320ab2b0 | 357 | evt->cpumask = cpumask_of(cpu); |
15c84731 | 358 | evt->irq = irq; |
f87e4cac JF |
359 | } |
360 | ||
d68d82af | 361 | |
f87e4cac JF |
362 | void xen_setup_cpu_clockevents(void) |
363 | { | |
89cbc767 | 364 | clockevents_register_device(this_cpu_ptr(&xen_clock_events.evt)); |
15c84731 JF |
365 | } |
366 | ||
d07af1f0 JF |
367 | void xen_timer_resume(void) |
368 | { | |
369 | int cpu; | |
370 | ||
371 | if (xen_clockevent != &xen_vcpuop_clockevent) | |
372 | return; | |
373 | ||
374 | for_each_online_cpu(cpu) { | |
ad5475f9 VK |
375 | if (HYPERVISOR_vcpu_op(VCPUOP_stop_periodic_timer, |
376 | xen_vcpu_nr(cpu), NULL)) | |
d07af1f0 JF |
377 | BUG(); |
378 | } | |
379 | } | |
380 | ||
fb6ce5de | 381 | static const struct pv_time_ops xen_time_ops __initconst = { |
38669ba2 | 382 | .sched_clock = xen_sched_clock, |
d34c30cc | 383 | .steal_clock = xen_steal_clock, |
409771d2 SS |
384 | }; |
385 | ||
2229f70b | 386 | static struct pvclock_vsyscall_time_info *xen_clock __read_mostly; |
867cefb4 | 387 | static u64 xen_clock_value_saved; |
2229f70b JM |
388 | |
389 | void xen_save_time_memory_area(void) | |
390 | { | |
391 | struct vcpu_register_time_memory_area t; | |
392 | int ret; | |
393 | ||
867cefb4 JG |
394 | xen_clock_value_saved = xen_clocksource_read() - xen_sched_clock_offset; |
395 | ||
2229f70b JM |
396 | if (!xen_clock) |
397 | return; | |
398 | ||
399 | t.addr.v = NULL; | |
400 | ||
401 | ret = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_time_memory_area, 0, &t); | |
402 | if (ret != 0) | |
403 | pr_notice("Cannot save secondary vcpu_time_info (err %d)", | |
404 | ret); | |
405 | else | |
406 | clear_page(xen_clock); | |
407 | } | |
408 | ||
409 | void xen_restore_time_memory_area(void) | |
410 | { | |
411 | struct vcpu_register_time_memory_area t; | |
412 | int ret; | |
413 | ||
414 | if (!xen_clock) | |
867cefb4 | 415 | goto out; |
2229f70b JM |
416 | |
417 | t.addr.v = &xen_clock->pvti; | |
418 | ||
419 | ret = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_time_memory_area, 0, &t); | |
420 | ||
421 | /* | |
422 | * We don't disable VCLOCK_PVCLOCK entirely if it fails to register the | |
423 | * secondary time info with Xen or if we migrated to a host without the | |
424 | * necessary flags. On both of these cases what happens is either | |
425 | * process seeing a zeroed out pvti or seeing no PVCLOCK_TSC_STABLE_BIT | |
426 | * bit set. Userspace checks the latter and if 0, it discards the data | |
427 | * in pvti and fallbacks to a system call for a reliable timestamp. | |
428 | */ | |
429 | if (ret != 0) | |
430 | pr_notice("Cannot restore secondary vcpu_time_info (err %d)", | |
431 | ret); | |
867cefb4 JG |
432 | |
433 | out: | |
434 | /* Need pvclock_resume() before using xen_clocksource_read(). */ | |
435 | pvclock_resume(); | |
436 | xen_sched_clock_offset = xen_clocksource_read() - xen_clock_value_saved; | |
2229f70b JM |
437 | } |
438 | ||
439 | static void xen_setup_vsyscall_time_info(void) | |
440 | { | |
441 | struct vcpu_register_time_memory_area t; | |
442 | struct pvclock_vsyscall_time_info *ti; | |
443 | int ret; | |
444 | ||
445 | ti = (struct pvclock_vsyscall_time_info *)get_zeroed_page(GFP_KERNEL); | |
446 | if (!ti) | |
447 | return; | |
448 | ||
449 | t.addr.v = &ti->pvti; | |
450 | ||
451 | ret = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_time_memory_area, 0, &t); | |
452 | if (ret) { | |
453 | pr_notice("xen: VCLOCK_PVCLOCK not supported (err %d)\n", ret); | |
454 | free_page((unsigned long)ti); | |
455 | return; | |
456 | } | |
457 | ||
458 | /* | |
459 | * If primary time info had this bit set, secondary should too since | |
460 | * it's the same data on both just different memory regions. But we | |
461 | * still check it in case hypervisor is buggy. | |
462 | */ | |
463 | if (!(ti->pvti.flags & PVCLOCK_TSC_STABLE_BIT)) { | |
464 | t.addr.v = NULL; | |
465 | ret = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_time_memory_area, | |
466 | 0, &t); | |
467 | if (!ret) | |
468 | free_page((unsigned long)ti); | |
469 | ||
470 | pr_notice("xen: VCLOCK_PVCLOCK not supported (tsc unstable)\n"); | |
471 | return; | |
472 | } | |
473 | ||
474 | xen_clock = ti; | |
475 | pvclock_set_pvti_cpu0_va(xen_clock); | |
476 | ||
477 | xen_clocksource.archdata.vclock_mode = VCLOCK_PVCLOCK; | |
478 | } | |
479 | ||
fb6ce5de | 480 | static void __init xen_time_init(void) |
15c84731 | 481 | { |
b8888080 | 482 | struct pvclock_vcpu_time_info *pvti; |
15c84731 | 483 | int cpu = smp_processor_id(); |
e27c4929 | 484 | struct timespec64 tp; |
15c84731 | 485 | |
94dd85f6 PI |
486 | /* As Dom0 is never moved, no penalty on using TSC there */ |
487 | if (xen_initial_domain()) | |
488 | xen_clocksource.rating = 275; | |
489 | ||
b01cc1b0 | 490 | clocksource_register_hz(&xen_clocksource, NSEC_PER_SEC); |
15c84731 | 491 | |
ad5475f9 VK |
492 | if (HYPERVISOR_vcpu_op(VCPUOP_stop_periodic_timer, xen_vcpu_nr(cpu), |
493 | NULL) == 0) { | |
f91a8b44 | 494 | /* Successfully turned off 100Hz tick, so we have the |
15c84731 JF |
495 | vcpuop-based timer interface */ |
496 | printk(KERN_DEBUG "Xen: using vcpuop timer interface\n"); | |
497 | xen_clockevent = &xen_vcpuop_clockevent; | |
498 | } | |
499 | ||
500 | /* Set initial system time with full resolution */ | |
c4507257 | 501 | xen_read_wallclock(&tp); |
e27c4929 | 502 | do_settimeofday64(&tp); |
15c84731 | 503 | |
404ee5b1 | 504 | setup_force_cpu_cap(X86_FEATURE_TSC); |
15c84731 | 505 | |
b8888080 JM |
506 | /* |
507 | * We check ahead on the primary time info if this | |
508 | * bit is supported hence speeding up Xen clocksource. | |
509 | */ | |
510 | pvti = &__this_cpu_read(xen_vcpu)->time; | |
2229f70b | 511 | if (pvti->flags & PVCLOCK_TSC_STABLE_BIT) { |
b8888080 | 512 | pvclock_set_flags(PVCLOCK_TSC_STABLE_BIT); |
2229f70b JM |
513 | xen_setup_vsyscall_time_info(); |
514 | } | |
b8888080 | 515 | |
be012920 | 516 | xen_setup_runstate_info(cpu); |
15c84731 | 517 | xen_setup_timer(cpu); |
f87e4cac | 518 | xen_setup_cpu_clockevents(); |
5584880e | 519 | |
ecb23dc6 JG |
520 | xen_time_setup_guest(); |
521 | ||
5584880e DV |
522 | if (xen_initial_domain()) |
523 | pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier); | |
15c84731 | 524 | } |
409771d2 | 525 | |
7b25b9cb | 526 | void __init xen_init_time_ops(void) |
409771d2 | 527 | { |
38669ba2 | 528 | xen_sched_clock_offset = xen_clocksource_read(); |
5c83511b | 529 | pv_ops.time = xen_time_ops; |
409771d2 SS |
530 | |
531 | x86_init.timers.timer_init = xen_time_init; | |
532 | x86_init.timers.setup_percpu_clockev = x86_init_noop; | |
533 | x86_cpuinit.setup_percpu_clockev = x86_init_noop; | |
534 | ||
535 | x86_platform.calibrate_tsc = xen_tsc_khz; | |
536 | x86_platform.get_wallclock = xen_get_wallclock; | |
47433b8c DV |
537 | /* Dom0 uses the native method to set the hardware RTC. */ |
538 | if (!xen_initial_domain()) | |
539 | x86_platform.set_wallclock = xen_set_wallclock; | |
409771d2 SS |
540 | } |
541 | ||
ca65f9fc | 542 | #ifdef CONFIG_XEN_PVHVM |
409771d2 SS |
543 | static void xen_hvm_setup_cpu_clockevents(void) |
544 | { | |
545 | int cpu = smp_processor_id(); | |
546 | xen_setup_runstate_info(cpu); | |
7918c92a KRW |
547 | /* |
548 | * xen_setup_timer(cpu) - snprintf is bad in atomic context. Hence | |
549 | * doing it xen_hvm_cpu_notify (which gets called by smp_init during | |
550 | * early bootup and also during CPU hotplug events). | |
551 | */ | |
409771d2 SS |
552 | xen_setup_cpu_clockevents(); |
553 | } | |
554 | ||
fb6ce5de | 555 | void __init xen_hvm_init_time_ops(void) |
409771d2 | 556 | { |
84d582d2 BO |
557 | /* |
558 | * vector callback is needed otherwise we cannot receive interrupts | |
559 | * on cpu > 0 and at this point we don't know how many cpus are | |
560 | * available. | |
561 | */ | |
562 | if (!xen_have_vector_callback) | |
563 | return; | |
564 | ||
409771d2 | 565 | if (!xen_feature(XENFEAT_hvm_safe_pvclock)) { |
7b25b9cb | 566 | pr_info("Xen doesn't support pvclock on HVM, disable pv timer"); |
409771d2 SS |
567 | return; |
568 | } | |
569 | ||
38669ba2 | 570 | xen_sched_clock_offset = xen_clocksource_read(); |
5c83511b | 571 | pv_ops.time = xen_time_ops; |
409771d2 SS |
572 | x86_init.timers.setup_percpu_clockev = xen_time_init; |
573 | x86_cpuinit.setup_percpu_clockev = xen_hvm_setup_cpu_clockevents; | |
574 | ||
575 | x86_platform.calibrate_tsc = xen_tsc_khz; | |
576 | x86_platform.get_wallclock = xen_get_wallclock; | |
577 | x86_platform.set_wallclock = xen_set_wallclock; | |
578 | } | |
ca65f9fc | 579 | #endif |
2ec16bc0 RT |
580 | |
581 | /* Kernel parameter to specify Xen timer slop */ | |
582 | static int __init parse_xen_timer_slop(char *ptr) | |
583 | { | |
584 | unsigned long slop = memparse(ptr, NULL); | |
585 | ||
586 | xen_timerop_clockevent.min_delta_ns = slop; | |
587 | xen_timerop_clockevent.min_delta_ticks = slop; | |
588 | xen_vcpuop_clockevent.min_delta_ns = slop; | |
589 | xen_vcpuop_clockevent.min_delta_ticks = slop; | |
590 | ||
591 | return 0; | |
592 | } | |
593 | early_param("xen_timer_slop", parse_xen_timer_slop); |