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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Virtual cpu timer based timer functions.
4 *
5 * Copyright IBM Corp. 2004, 2012
6 * Author(s): Jan Glauber <jan.glauber@de.ibm.com>
7 */
8
9#include <linux/kernel_stat.h>
10#include <linux/export.h>
11#include <linux/kernel.h>
12#include <linux/timex.h>
13#include <linux/types.h>
14#include <linux/time.h>
15#include <asm/alternative.h>
16#include <asm/cputime.h>
17#include <asm/vtimer.h>
18#include <asm/vtime.h>
19#include <asm/cpu_mf.h>
20#include <asm/smp.h>
21
22#include "entry.h"
23
24static void virt_timer_expire(void);
25
26static LIST_HEAD(virt_timer_list);
27static DEFINE_SPINLOCK(virt_timer_lock);
28static atomic64_t virt_timer_current;
29static atomic64_t virt_timer_elapsed;
30
31DEFINE_PER_CPU(u64, mt_cycles[8]);
32static DEFINE_PER_CPU(u64, mt_scaling_mult) = { 1 };
33static DEFINE_PER_CPU(u64, mt_scaling_div) = { 1 };
34static DEFINE_PER_CPU(u64, mt_scaling_jiffies);
35
36static inline u64 get_vtimer(void)
37{
38 u64 timer;
39
40 asm volatile("stpt %0" : "=Q" (timer));
41 return timer;
42}
43
44static inline void set_vtimer(u64 expires)
45{
46 u64 timer;
47
48 asm volatile(
49 " stpt %0\n" /* Store current cpu timer value */
50 " spt %1" /* Set new value imm. afterwards */
51 : "=Q" (timer) : "Q" (expires));
52 S390_lowcore.system_timer += S390_lowcore.last_update_timer - timer;
53 S390_lowcore.last_update_timer = expires;
54}
55
56static inline int virt_timer_forward(u64 elapsed)
57{
58 BUG_ON(!irqs_disabled());
59
60 if (list_empty(&virt_timer_list))
61 return 0;
62 elapsed = atomic64_add_return(elapsed, &virt_timer_elapsed);
63 return elapsed >= atomic64_read(&virt_timer_current);
64}
65
66static void update_mt_scaling(void)
67{
68 u64 cycles_new[8], *cycles_old;
69 u64 delta, fac, mult, div;
70 int i;
71
72 stcctm(MT_DIAG, smp_cpu_mtid + 1, cycles_new);
73 cycles_old = this_cpu_ptr(mt_cycles);
74 fac = 1;
75 mult = div = 0;
76 for (i = 0; i <= smp_cpu_mtid; i++) {
77 delta = cycles_new[i] - cycles_old[i];
78 div += delta;
79 mult *= i + 1;
80 mult += delta * fac;
81 fac *= i + 1;
82 }
83 div *= fac;
84 if (div > 0) {
85 /* Update scaling factor */
86 __this_cpu_write(mt_scaling_mult, mult);
87 __this_cpu_write(mt_scaling_div, div);
88 memcpy(cycles_old, cycles_new,
89 sizeof(u64) * (smp_cpu_mtid + 1));
90 }
91 __this_cpu_write(mt_scaling_jiffies, jiffies_64);
92}
93
94static inline u64 update_tsk_timer(unsigned long *tsk_vtime, u64 new)
95{
96 u64 delta;
97
98 delta = new - *tsk_vtime;
99 *tsk_vtime = new;
100 return delta;
101}
102
103
104static inline u64 scale_vtime(u64 vtime)
105{
106 u64 mult = __this_cpu_read(mt_scaling_mult);
107 u64 div = __this_cpu_read(mt_scaling_div);
108
109 if (smp_cpu_mtid)
110 return vtime * mult / div;
111 return vtime;
112}
113
114static void account_system_index_scaled(struct task_struct *p, u64 cputime,
115 enum cpu_usage_stat index)
116{
117 p->stimescaled += cputime_to_nsecs(scale_vtime(cputime));
118 account_system_index_time(p, cputime_to_nsecs(cputime), index);
119}
120
121/*
122 * Update process times based on virtual cpu times stored by entry.S
123 * to the lowcore fields user_timer, system_timer & steal_clock.
124 */
125static int do_account_vtime(struct task_struct *tsk)
126{
127 u64 timer, clock, user, guest, system, hardirq, softirq;
128
129 timer = S390_lowcore.last_update_timer;
130 clock = S390_lowcore.last_update_clock;
131 asm volatile(
132 " stpt %0\n" /* Store current cpu timer value */
133 " stckf %1" /* Store current tod clock value */
134 : "=Q" (S390_lowcore.last_update_timer),
135 "=Q" (S390_lowcore.last_update_clock)
136 : : "cc");
137 clock = S390_lowcore.last_update_clock - clock;
138 timer -= S390_lowcore.last_update_timer;
139
140 if (hardirq_count())
141 S390_lowcore.hardirq_timer += timer;
142 else
143 S390_lowcore.system_timer += timer;
144
145 /* Update MT utilization calculation */
146 if (smp_cpu_mtid &&
147 time_after64(jiffies_64, this_cpu_read(mt_scaling_jiffies)))
148 update_mt_scaling();
149
150 /* Calculate cputime delta */
151 user = update_tsk_timer(&tsk->thread.user_timer,
152 READ_ONCE(S390_lowcore.user_timer));
153 guest = update_tsk_timer(&tsk->thread.guest_timer,
154 READ_ONCE(S390_lowcore.guest_timer));
155 system = update_tsk_timer(&tsk->thread.system_timer,
156 READ_ONCE(S390_lowcore.system_timer));
157 hardirq = update_tsk_timer(&tsk->thread.hardirq_timer,
158 READ_ONCE(S390_lowcore.hardirq_timer));
159 softirq = update_tsk_timer(&tsk->thread.softirq_timer,
160 READ_ONCE(S390_lowcore.softirq_timer));
161 S390_lowcore.steal_timer +=
162 clock - user - guest - system - hardirq - softirq;
163
164 /* Push account value */
165 if (user) {
166 account_user_time(tsk, cputime_to_nsecs(user));
167 tsk->utimescaled += cputime_to_nsecs(scale_vtime(user));
168 }
169
170 if (guest) {
171 account_guest_time(tsk, cputime_to_nsecs(guest));
172 tsk->utimescaled += cputime_to_nsecs(scale_vtime(guest));
173 }
174
175 if (system)
176 account_system_index_scaled(tsk, system, CPUTIME_SYSTEM);
177 if (hardirq)
178 account_system_index_scaled(tsk, hardirq, CPUTIME_IRQ);
179 if (softirq)
180 account_system_index_scaled(tsk, softirq, CPUTIME_SOFTIRQ);
181
182 return virt_timer_forward(user + guest + system + hardirq + softirq);
183}
184
185void vtime_task_switch(struct task_struct *prev)
186{
187 do_account_vtime(prev);
188 prev->thread.user_timer = S390_lowcore.user_timer;
189 prev->thread.guest_timer = S390_lowcore.guest_timer;
190 prev->thread.system_timer = S390_lowcore.system_timer;
191 prev->thread.hardirq_timer = S390_lowcore.hardirq_timer;
192 prev->thread.softirq_timer = S390_lowcore.softirq_timer;
193 S390_lowcore.user_timer = current->thread.user_timer;
194 S390_lowcore.guest_timer = current->thread.guest_timer;
195 S390_lowcore.system_timer = current->thread.system_timer;
196 S390_lowcore.hardirq_timer = current->thread.hardirq_timer;
197 S390_lowcore.softirq_timer = current->thread.softirq_timer;
198}
199
200/*
201 * In s390, accounting pending user time also implies
202 * accounting system time in order to correctly compute
203 * the stolen time accounting.
204 */
205void vtime_flush(struct task_struct *tsk)
206{
207 u64 steal, avg_steal;
208
209 if (do_account_vtime(tsk))
210 virt_timer_expire();
211
212 steal = S390_lowcore.steal_timer;
213 avg_steal = S390_lowcore.avg_steal_timer / 2;
214 if ((s64) steal > 0) {
215 S390_lowcore.steal_timer = 0;
216 account_steal_time(cputime_to_nsecs(steal));
217 avg_steal += steal;
218 }
219 S390_lowcore.avg_steal_timer = avg_steal;
220}
221
222static u64 vtime_delta(void)
223{
224 u64 timer = S390_lowcore.last_update_timer;
225
226 S390_lowcore.last_update_timer = get_vtimer();
227
228 return timer - S390_lowcore.last_update_timer;
229}
230
231/*
232 * Update process times based on virtual cpu times stored by entry.S
233 * to the lowcore fields user_timer, system_timer & steal_clock.
234 */
235void vtime_account_kernel(struct task_struct *tsk)
236{
237 u64 delta = vtime_delta();
238
239 if (tsk->flags & PF_VCPU)
240 S390_lowcore.guest_timer += delta;
241 else
242 S390_lowcore.system_timer += delta;
243
244 virt_timer_forward(delta);
245}
246EXPORT_SYMBOL_GPL(vtime_account_kernel);
247
248void vtime_account_softirq(struct task_struct *tsk)
249{
250 u64 delta = vtime_delta();
251
252 S390_lowcore.softirq_timer += delta;
253
254 virt_timer_forward(delta);
255}
256
257void vtime_account_hardirq(struct task_struct *tsk)
258{
259 u64 delta = vtime_delta();
260
261 S390_lowcore.hardirq_timer += delta;
262
263 virt_timer_forward(delta);
264}
265
266/*
267 * Sorted add to a list. List is linear searched until first bigger
268 * element is found.
269 */
270static void list_add_sorted(struct vtimer_list *timer, struct list_head *head)
271{
272 struct vtimer_list *tmp;
273
274 list_for_each_entry(tmp, head, entry) {
275 if (tmp->expires > timer->expires) {
276 list_add_tail(&timer->entry, &tmp->entry);
277 return;
278 }
279 }
280 list_add_tail(&timer->entry, head);
281}
282
283/*
284 * Handler for expired virtual CPU timer.
285 */
286static void virt_timer_expire(void)
287{
288 struct vtimer_list *timer, *tmp;
289 unsigned long elapsed;
290 LIST_HEAD(cb_list);
291
292 /* walk timer list, fire all expired timers */
293 spin_lock(&virt_timer_lock);
294 elapsed = atomic64_read(&virt_timer_elapsed);
295 list_for_each_entry_safe(timer, tmp, &virt_timer_list, entry) {
296 if (timer->expires < elapsed)
297 /* move expired timer to the callback queue */
298 list_move_tail(&timer->entry, &cb_list);
299 else
300 timer->expires -= elapsed;
301 }
302 if (!list_empty(&virt_timer_list)) {
303 timer = list_first_entry(&virt_timer_list,
304 struct vtimer_list, entry);
305 atomic64_set(&virt_timer_current, timer->expires);
306 }
307 atomic64_sub(elapsed, &virt_timer_elapsed);
308 spin_unlock(&virt_timer_lock);
309
310 /* Do callbacks and recharge periodic timers */
311 list_for_each_entry_safe(timer, tmp, &cb_list, entry) {
312 list_del_init(&timer->entry);
313 timer->function(timer->data);
314 if (timer->interval) {
315 /* Recharge interval timer */
316 timer->expires = timer->interval +
317 atomic64_read(&virt_timer_elapsed);
318 spin_lock(&virt_timer_lock);
319 list_add_sorted(timer, &virt_timer_list);
320 spin_unlock(&virt_timer_lock);
321 }
322 }
323}
324
325void init_virt_timer(struct vtimer_list *timer)
326{
327 timer->function = NULL;
328 INIT_LIST_HEAD(&timer->entry);
329}
330EXPORT_SYMBOL(init_virt_timer);
331
332static inline int vtimer_pending(struct vtimer_list *timer)
333{
334 return !list_empty(&timer->entry);
335}
336
337static void internal_add_vtimer(struct vtimer_list *timer)
338{
339 if (list_empty(&virt_timer_list)) {
340 /* First timer, just program it. */
341 atomic64_set(&virt_timer_current, timer->expires);
342 atomic64_set(&virt_timer_elapsed, 0);
343 list_add(&timer->entry, &virt_timer_list);
344 } else {
345 /* Update timer against current base. */
346 timer->expires += atomic64_read(&virt_timer_elapsed);
347 if (likely((s64) timer->expires <
348 (s64) atomic64_read(&virt_timer_current)))
349 /* The new timer expires before the current timer. */
350 atomic64_set(&virt_timer_current, timer->expires);
351 /* Insert new timer into the list. */
352 list_add_sorted(timer, &virt_timer_list);
353 }
354}
355
356static void __add_vtimer(struct vtimer_list *timer, int periodic)
357{
358 unsigned long flags;
359
360 timer->interval = periodic ? timer->expires : 0;
361 spin_lock_irqsave(&virt_timer_lock, flags);
362 internal_add_vtimer(timer);
363 spin_unlock_irqrestore(&virt_timer_lock, flags);
364}
365
366/*
367 * add_virt_timer - add a oneshot virtual CPU timer
368 */
369void add_virt_timer(struct vtimer_list *timer)
370{
371 __add_vtimer(timer, 0);
372}
373EXPORT_SYMBOL(add_virt_timer);
374
375/*
376 * add_virt_timer_int - add an interval virtual CPU timer
377 */
378void add_virt_timer_periodic(struct vtimer_list *timer)
379{
380 __add_vtimer(timer, 1);
381}
382EXPORT_SYMBOL(add_virt_timer_periodic);
383
384static int __mod_vtimer(struct vtimer_list *timer, u64 expires, int periodic)
385{
386 unsigned long flags;
387 int rc;
388
389 BUG_ON(!timer->function);
390
391 if (timer->expires == expires && vtimer_pending(timer))
392 return 1;
393 spin_lock_irqsave(&virt_timer_lock, flags);
394 rc = vtimer_pending(timer);
395 if (rc)
396 list_del_init(&timer->entry);
397 timer->interval = periodic ? expires : 0;
398 timer->expires = expires;
399 internal_add_vtimer(timer);
400 spin_unlock_irqrestore(&virt_timer_lock, flags);
401 return rc;
402}
403
404/*
405 * returns whether it has modified a pending timer (1) or not (0)
406 */
407int mod_virt_timer(struct vtimer_list *timer, u64 expires)
408{
409 return __mod_vtimer(timer, expires, 0);
410}
411EXPORT_SYMBOL(mod_virt_timer);
412
413/*
414 * returns whether it has modified a pending timer (1) or not (0)
415 */
416int mod_virt_timer_periodic(struct vtimer_list *timer, u64 expires)
417{
418 return __mod_vtimer(timer, expires, 1);
419}
420EXPORT_SYMBOL(mod_virt_timer_periodic);
421
422/*
423 * Delete a virtual timer.
424 *
425 * returns whether the deleted timer was pending (1) or not (0)
426 */
427int del_virt_timer(struct vtimer_list *timer)
428{
429 unsigned long flags;
430
431 if (!vtimer_pending(timer))
432 return 0;
433 spin_lock_irqsave(&virt_timer_lock, flags);
434 list_del_init(&timer->entry);
435 spin_unlock_irqrestore(&virt_timer_lock, flags);
436 return 1;
437}
438EXPORT_SYMBOL(del_virt_timer);
439
440/*
441 * Start the virtual CPU timer on the current CPU.
442 */
443void vtime_init(void)
444{
445 /* set initial cpu timer */
446 set_vtimer(VTIMER_MAX_SLICE);
447 /* Setup initial MT scaling values */
448 if (smp_cpu_mtid) {
449 __this_cpu_write(mt_scaling_jiffies, jiffies);
450 __this_cpu_write(mt_scaling_mult, 1);
451 __this_cpu_write(mt_scaling_div, 1);
452 stcctm(MT_DIAG, smp_cpu_mtid + 1, this_cpu_ptr(mt_cycles));
453 }
454}
1/*
2 * Virtual cpu timer based timer functions.
3 *
4 * Copyright IBM Corp. 2004, 2012
5 * Author(s): Jan Glauber <jan.glauber@de.ibm.com>
6 */
7
8#include <linux/kernel_stat.h>
9#include <linux/export.h>
10#include <linux/kernel.h>
11#include <linux/timex.h>
12#include <linux/types.h>
13#include <linux/time.h>
14
15#include <asm/cputime.h>
16#include <asm/vtimer.h>
17#include <asm/vtime.h>
18#include <asm/cpu_mf.h>
19#include <asm/smp.h>
20
21static void virt_timer_expire(void);
22
23static LIST_HEAD(virt_timer_list);
24static DEFINE_SPINLOCK(virt_timer_lock);
25static atomic64_t virt_timer_current;
26static atomic64_t virt_timer_elapsed;
27
28DEFINE_PER_CPU(u64, mt_cycles[8]);
29static DEFINE_PER_CPU(u64, mt_scaling_mult) = { 1 };
30static DEFINE_PER_CPU(u64, mt_scaling_div) = { 1 };
31static DEFINE_PER_CPU(u64, mt_scaling_jiffies);
32
33static inline u64 get_vtimer(void)
34{
35 u64 timer;
36
37 asm volatile("stpt %0" : "=m" (timer));
38 return timer;
39}
40
41static inline void set_vtimer(u64 expires)
42{
43 u64 timer;
44
45 asm volatile(
46 " stpt %0\n" /* Store current cpu timer value */
47 " spt %1" /* Set new value imm. afterwards */
48 : "=m" (timer) : "m" (expires));
49 S390_lowcore.system_timer += S390_lowcore.last_update_timer - timer;
50 S390_lowcore.last_update_timer = expires;
51}
52
53static inline int virt_timer_forward(u64 elapsed)
54{
55 BUG_ON(!irqs_disabled());
56
57 if (list_empty(&virt_timer_list))
58 return 0;
59 elapsed = atomic64_add_return(elapsed, &virt_timer_elapsed);
60 return elapsed >= atomic64_read(&virt_timer_current);
61}
62
63static void update_mt_scaling(void)
64{
65 u64 cycles_new[8], *cycles_old;
66 u64 delta, fac, mult, div;
67 int i;
68
69 stcctm5(smp_cpu_mtid + 1, cycles_new);
70 cycles_old = this_cpu_ptr(mt_cycles);
71 fac = 1;
72 mult = div = 0;
73 for (i = 0; i <= smp_cpu_mtid; i++) {
74 delta = cycles_new[i] - cycles_old[i];
75 div += delta;
76 mult *= i + 1;
77 mult += delta * fac;
78 fac *= i + 1;
79 }
80 div *= fac;
81 if (div > 0) {
82 /* Update scaling factor */
83 __this_cpu_write(mt_scaling_mult, mult);
84 __this_cpu_write(mt_scaling_div, div);
85 memcpy(cycles_old, cycles_new,
86 sizeof(u64) * (smp_cpu_mtid + 1));
87 }
88 __this_cpu_write(mt_scaling_jiffies, jiffies_64);
89}
90
91/*
92 * Update process times based on virtual cpu times stored by entry.S
93 * to the lowcore fields user_timer, system_timer & steal_clock.
94 */
95static int do_account_vtime(struct task_struct *tsk, int hardirq_offset)
96{
97 struct thread_info *ti = task_thread_info(tsk);
98 u64 timer, clock, user, system, steal;
99 u64 user_scaled, system_scaled;
100
101 timer = S390_lowcore.last_update_timer;
102 clock = S390_lowcore.last_update_clock;
103 asm volatile(
104 " stpt %0\n" /* Store current cpu timer value */
105#ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
106 " stckf %1" /* Store current tod clock value */
107#else
108 " stck %1" /* Store current tod clock value */
109#endif
110 : "=m" (S390_lowcore.last_update_timer),
111 "=m" (S390_lowcore.last_update_clock));
112 S390_lowcore.system_timer += timer - S390_lowcore.last_update_timer;
113 S390_lowcore.steal_timer += S390_lowcore.last_update_clock - clock;
114
115 /* Update MT utilization calculation */
116 if (smp_cpu_mtid &&
117 time_after64(jiffies_64, this_cpu_read(mt_scaling_jiffies)))
118 update_mt_scaling();
119
120 user = S390_lowcore.user_timer - ti->user_timer;
121 S390_lowcore.steal_timer -= user;
122 ti->user_timer = S390_lowcore.user_timer;
123
124 system = S390_lowcore.system_timer - ti->system_timer;
125 S390_lowcore.steal_timer -= system;
126 ti->system_timer = S390_lowcore.system_timer;
127
128 user_scaled = user;
129 system_scaled = system;
130 /* Do MT utilization scaling */
131 if (smp_cpu_mtid) {
132 u64 mult = __this_cpu_read(mt_scaling_mult);
133 u64 div = __this_cpu_read(mt_scaling_div);
134
135 user_scaled = (user_scaled * mult) / div;
136 system_scaled = (system_scaled * mult) / div;
137 }
138 account_user_time(tsk, user, user_scaled);
139 account_system_time(tsk, hardirq_offset, system, system_scaled);
140
141 steal = S390_lowcore.steal_timer;
142 if ((s64) steal > 0) {
143 S390_lowcore.steal_timer = 0;
144 account_steal_time(steal);
145 }
146
147 return virt_timer_forward(user + system);
148}
149
150void vtime_task_switch(struct task_struct *prev)
151{
152 struct thread_info *ti;
153
154 do_account_vtime(prev, 0);
155 ti = task_thread_info(prev);
156 ti->user_timer = S390_lowcore.user_timer;
157 ti->system_timer = S390_lowcore.system_timer;
158 ti = task_thread_info(current);
159 S390_lowcore.user_timer = ti->user_timer;
160 S390_lowcore.system_timer = ti->system_timer;
161}
162
163/*
164 * In s390, accounting pending user time also implies
165 * accounting system time in order to correctly compute
166 * the stolen time accounting.
167 */
168void vtime_account_user(struct task_struct *tsk)
169{
170 if (do_account_vtime(tsk, HARDIRQ_OFFSET))
171 virt_timer_expire();
172}
173
174/*
175 * Update process times based on virtual cpu times stored by entry.S
176 * to the lowcore fields user_timer, system_timer & steal_clock.
177 */
178void vtime_account_irq_enter(struct task_struct *tsk)
179{
180 struct thread_info *ti = task_thread_info(tsk);
181 u64 timer, system, system_scaled;
182
183 timer = S390_lowcore.last_update_timer;
184 S390_lowcore.last_update_timer = get_vtimer();
185 S390_lowcore.system_timer += timer - S390_lowcore.last_update_timer;
186
187 /* Update MT utilization calculation */
188 if (smp_cpu_mtid &&
189 time_after64(jiffies_64, this_cpu_read(mt_scaling_jiffies)))
190 update_mt_scaling();
191
192 system = S390_lowcore.system_timer - ti->system_timer;
193 S390_lowcore.steal_timer -= system;
194 ti->system_timer = S390_lowcore.system_timer;
195 system_scaled = system;
196 /* Do MT utilization scaling */
197 if (smp_cpu_mtid) {
198 u64 mult = __this_cpu_read(mt_scaling_mult);
199 u64 div = __this_cpu_read(mt_scaling_div);
200
201 system_scaled = (system_scaled * mult) / div;
202 }
203 account_system_time(tsk, 0, system, system_scaled);
204
205 virt_timer_forward(system);
206}
207EXPORT_SYMBOL_GPL(vtime_account_irq_enter);
208
209void vtime_account_system(struct task_struct *tsk)
210__attribute__((alias("vtime_account_irq_enter")));
211EXPORT_SYMBOL_GPL(vtime_account_system);
212
213/*
214 * Sorted add to a list. List is linear searched until first bigger
215 * element is found.
216 */
217static void list_add_sorted(struct vtimer_list *timer, struct list_head *head)
218{
219 struct vtimer_list *tmp;
220
221 list_for_each_entry(tmp, head, entry) {
222 if (tmp->expires > timer->expires) {
223 list_add_tail(&timer->entry, &tmp->entry);
224 return;
225 }
226 }
227 list_add_tail(&timer->entry, head);
228}
229
230/*
231 * Handler for expired virtual CPU timer.
232 */
233static void virt_timer_expire(void)
234{
235 struct vtimer_list *timer, *tmp;
236 unsigned long elapsed;
237 LIST_HEAD(cb_list);
238
239 /* walk timer list, fire all expired timers */
240 spin_lock(&virt_timer_lock);
241 elapsed = atomic64_read(&virt_timer_elapsed);
242 list_for_each_entry_safe(timer, tmp, &virt_timer_list, entry) {
243 if (timer->expires < elapsed)
244 /* move expired timer to the callback queue */
245 list_move_tail(&timer->entry, &cb_list);
246 else
247 timer->expires -= elapsed;
248 }
249 if (!list_empty(&virt_timer_list)) {
250 timer = list_first_entry(&virt_timer_list,
251 struct vtimer_list, entry);
252 atomic64_set(&virt_timer_current, timer->expires);
253 }
254 atomic64_sub(elapsed, &virt_timer_elapsed);
255 spin_unlock(&virt_timer_lock);
256
257 /* Do callbacks and recharge periodic timers */
258 list_for_each_entry_safe(timer, tmp, &cb_list, entry) {
259 list_del_init(&timer->entry);
260 timer->function(timer->data);
261 if (timer->interval) {
262 /* Recharge interval timer */
263 timer->expires = timer->interval +
264 atomic64_read(&virt_timer_elapsed);
265 spin_lock(&virt_timer_lock);
266 list_add_sorted(timer, &virt_timer_list);
267 spin_unlock(&virt_timer_lock);
268 }
269 }
270}
271
272void init_virt_timer(struct vtimer_list *timer)
273{
274 timer->function = NULL;
275 INIT_LIST_HEAD(&timer->entry);
276}
277EXPORT_SYMBOL(init_virt_timer);
278
279static inline int vtimer_pending(struct vtimer_list *timer)
280{
281 return !list_empty(&timer->entry);
282}
283
284static void internal_add_vtimer(struct vtimer_list *timer)
285{
286 if (list_empty(&virt_timer_list)) {
287 /* First timer, just program it. */
288 atomic64_set(&virt_timer_current, timer->expires);
289 atomic64_set(&virt_timer_elapsed, 0);
290 list_add(&timer->entry, &virt_timer_list);
291 } else {
292 /* Update timer against current base. */
293 timer->expires += atomic64_read(&virt_timer_elapsed);
294 if (likely((s64) timer->expires <
295 (s64) atomic64_read(&virt_timer_current)))
296 /* The new timer expires before the current timer. */
297 atomic64_set(&virt_timer_current, timer->expires);
298 /* Insert new timer into the list. */
299 list_add_sorted(timer, &virt_timer_list);
300 }
301}
302
303static void __add_vtimer(struct vtimer_list *timer, int periodic)
304{
305 unsigned long flags;
306
307 timer->interval = periodic ? timer->expires : 0;
308 spin_lock_irqsave(&virt_timer_lock, flags);
309 internal_add_vtimer(timer);
310 spin_unlock_irqrestore(&virt_timer_lock, flags);
311}
312
313/*
314 * add_virt_timer - add an oneshot virtual CPU timer
315 */
316void add_virt_timer(struct vtimer_list *timer)
317{
318 __add_vtimer(timer, 0);
319}
320EXPORT_SYMBOL(add_virt_timer);
321
322/*
323 * add_virt_timer_int - add an interval virtual CPU timer
324 */
325void add_virt_timer_periodic(struct vtimer_list *timer)
326{
327 __add_vtimer(timer, 1);
328}
329EXPORT_SYMBOL(add_virt_timer_periodic);
330
331static int __mod_vtimer(struct vtimer_list *timer, u64 expires, int periodic)
332{
333 unsigned long flags;
334 int rc;
335
336 BUG_ON(!timer->function);
337
338 if (timer->expires == expires && vtimer_pending(timer))
339 return 1;
340 spin_lock_irqsave(&virt_timer_lock, flags);
341 rc = vtimer_pending(timer);
342 if (rc)
343 list_del_init(&timer->entry);
344 timer->interval = periodic ? expires : 0;
345 timer->expires = expires;
346 internal_add_vtimer(timer);
347 spin_unlock_irqrestore(&virt_timer_lock, flags);
348 return rc;
349}
350
351/*
352 * returns whether it has modified a pending timer (1) or not (0)
353 */
354int mod_virt_timer(struct vtimer_list *timer, u64 expires)
355{
356 return __mod_vtimer(timer, expires, 0);
357}
358EXPORT_SYMBOL(mod_virt_timer);
359
360/*
361 * returns whether it has modified a pending timer (1) or not (0)
362 */
363int mod_virt_timer_periodic(struct vtimer_list *timer, u64 expires)
364{
365 return __mod_vtimer(timer, expires, 1);
366}
367EXPORT_SYMBOL(mod_virt_timer_periodic);
368
369/*
370 * Delete a virtual timer.
371 *
372 * returns whether the deleted timer was pending (1) or not (0)
373 */
374int del_virt_timer(struct vtimer_list *timer)
375{
376 unsigned long flags;
377
378 if (!vtimer_pending(timer))
379 return 0;
380 spin_lock_irqsave(&virt_timer_lock, flags);
381 list_del_init(&timer->entry);
382 spin_unlock_irqrestore(&virt_timer_lock, flags);
383 return 1;
384}
385EXPORT_SYMBOL(del_virt_timer);
386
387/*
388 * Start the virtual CPU timer on the current CPU.
389 */
390void vtime_init(void)
391{
392 /* set initial cpu timer */
393 set_vtimer(VTIMER_MAX_SLICE);
394 /* Setup initial MT scaling values */
395 if (smp_cpu_mtid) {
396 __this_cpu_write(mt_scaling_jiffies, jiffies);
397 __this_cpu_write(mt_scaling_mult, 1);
398 __this_cpu_write(mt_scaling_div, 1);
399 stcctm5(smp_cpu_mtid + 1, this_cpu_ptr(mt_cycles));
400 }
401}