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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/sched/cputime.h>
11#include <linux/export.h>
12#include <linux/kernel.h>
13#include <linux/timex.h>
14#include <linux/types.h>
15#include <linux/time.h>
16#include <asm/alternative.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// 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/sched/cputime.h>
11#include <linux/export.h>
12#include <linux/kernel.h>
13#include <linux/timex.h>
14#include <linux/types.h>
15#include <linux/time.h>
16
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" : "=m" (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 : "=m" (timer) : "m" (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 stcctm5(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, steal;
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#ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
134 " stckf %1" /* Store current tod clock value */
135#else
136 " stck %1" /* Store current tod clock value */
137#endif
138 : "=m" (S390_lowcore.last_update_timer),
139 "=m" (S390_lowcore.last_update_clock));
140 clock = S390_lowcore.last_update_clock - clock;
141 timer -= S390_lowcore.last_update_timer;
142
143 if (hardirq_count())
144 S390_lowcore.hardirq_timer += timer;
145 else
146 S390_lowcore.system_timer += timer;
147
148 /* Update MT utilization calculation */
149 if (smp_cpu_mtid &&
150 time_after64(jiffies_64, this_cpu_read(mt_scaling_jiffies)))
151 update_mt_scaling();
152
153 /* Calculate cputime delta */
154 user = update_tsk_timer(&tsk->thread.user_timer,
155 READ_ONCE(S390_lowcore.user_timer));
156 guest = update_tsk_timer(&tsk->thread.guest_timer,
157 READ_ONCE(S390_lowcore.guest_timer));
158 system = update_tsk_timer(&tsk->thread.system_timer,
159 READ_ONCE(S390_lowcore.system_timer));
160 hardirq = update_tsk_timer(&tsk->thread.hardirq_timer,
161 READ_ONCE(S390_lowcore.hardirq_timer));
162 softirq = update_tsk_timer(&tsk->thread.softirq_timer,
163 READ_ONCE(S390_lowcore.softirq_timer));
164 S390_lowcore.steal_timer +=
165 clock - user - guest - system - hardirq - softirq;
166
167 /* Push account value */
168 if (user) {
169 account_user_time(tsk, cputime_to_nsecs(user));
170 tsk->utimescaled += cputime_to_nsecs(scale_vtime(user));
171 }
172
173 if (guest) {
174 account_guest_time(tsk, cputime_to_nsecs(guest));
175 tsk->utimescaled += cputime_to_nsecs(scale_vtime(guest));
176 }
177
178 if (system)
179 account_system_index_scaled(tsk, system, CPUTIME_SYSTEM);
180 if (hardirq)
181 account_system_index_scaled(tsk, hardirq, CPUTIME_IRQ);
182 if (softirq)
183 account_system_index_scaled(tsk, softirq, CPUTIME_SOFTIRQ);
184
185 steal = S390_lowcore.steal_timer;
186 if ((s64) steal > 0) {
187 S390_lowcore.steal_timer = 0;
188 account_steal_time(cputime_to_nsecs(steal));
189 }
190
191 return virt_timer_forward(user + guest + system + hardirq + softirq);
192}
193
194void vtime_task_switch(struct task_struct *prev)
195{
196 do_account_vtime(prev);
197 prev->thread.user_timer = S390_lowcore.user_timer;
198 prev->thread.guest_timer = S390_lowcore.guest_timer;
199 prev->thread.system_timer = S390_lowcore.system_timer;
200 prev->thread.hardirq_timer = S390_lowcore.hardirq_timer;
201 prev->thread.softirq_timer = S390_lowcore.softirq_timer;
202 S390_lowcore.user_timer = current->thread.user_timer;
203 S390_lowcore.guest_timer = current->thread.guest_timer;
204 S390_lowcore.system_timer = current->thread.system_timer;
205 S390_lowcore.hardirq_timer = current->thread.hardirq_timer;
206 S390_lowcore.softirq_timer = current->thread.softirq_timer;
207}
208
209/*
210 * In s390, accounting pending user time also implies
211 * accounting system time in order to correctly compute
212 * the stolen time accounting.
213 */
214void vtime_flush(struct task_struct *tsk)
215{
216 if (do_account_vtime(tsk))
217 virt_timer_expire();
218}
219
220/*
221 * Update process times based on virtual cpu times stored by entry.S
222 * to the lowcore fields user_timer, system_timer & steal_clock.
223 */
224void vtime_account_irq_enter(struct task_struct *tsk)
225{
226 u64 timer;
227
228 timer = S390_lowcore.last_update_timer;
229 S390_lowcore.last_update_timer = get_vtimer();
230 timer -= S390_lowcore.last_update_timer;
231
232 if ((tsk->flags & PF_VCPU) && (irq_count() == 0))
233 S390_lowcore.guest_timer += timer;
234 else if (hardirq_count())
235 S390_lowcore.hardirq_timer += timer;
236 else if (in_serving_softirq())
237 S390_lowcore.softirq_timer += timer;
238 else
239 S390_lowcore.system_timer += timer;
240
241 virt_timer_forward(timer);
242}
243EXPORT_SYMBOL_GPL(vtime_account_irq_enter);
244
245void vtime_account_system(struct task_struct *tsk)
246__attribute__((alias("vtime_account_irq_enter")));
247EXPORT_SYMBOL_GPL(vtime_account_system);
248
249/*
250 * Sorted add to a list. List is linear searched until first bigger
251 * element is found.
252 */
253static void list_add_sorted(struct vtimer_list *timer, struct list_head *head)
254{
255 struct vtimer_list *tmp;
256
257 list_for_each_entry(tmp, head, entry) {
258 if (tmp->expires > timer->expires) {
259 list_add_tail(&timer->entry, &tmp->entry);
260 return;
261 }
262 }
263 list_add_tail(&timer->entry, head);
264}
265
266/*
267 * Handler for expired virtual CPU timer.
268 */
269static void virt_timer_expire(void)
270{
271 struct vtimer_list *timer, *tmp;
272 unsigned long elapsed;
273 LIST_HEAD(cb_list);
274
275 /* walk timer list, fire all expired timers */
276 spin_lock(&virt_timer_lock);
277 elapsed = atomic64_read(&virt_timer_elapsed);
278 list_for_each_entry_safe(timer, tmp, &virt_timer_list, entry) {
279 if (timer->expires < elapsed)
280 /* move expired timer to the callback queue */
281 list_move_tail(&timer->entry, &cb_list);
282 else
283 timer->expires -= elapsed;
284 }
285 if (!list_empty(&virt_timer_list)) {
286 timer = list_first_entry(&virt_timer_list,
287 struct vtimer_list, entry);
288 atomic64_set(&virt_timer_current, timer->expires);
289 }
290 atomic64_sub(elapsed, &virt_timer_elapsed);
291 spin_unlock(&virt_timer_lock);
292
293 /* Do callbacks and recharge periodic timers */
294 list_for_each_entry_safe(timer, tmp, &cb_list, entry) {
295 list_del_init(&timer->entry);
296 timer->function(timer->data);
297 if (timer->interval) {
298 /* Recharge interval timer */
299 timer->expires = timer->interval +
300 atomic64_read(&virt_timer_elapsed);
301 spin_lock(&virt_timer_lock);
302 list_add_sorted(timer, &virt_timer_list);
303 spin_unlock(&virt_timer_lock);
304 }
305 }
306}
307
308void init_virt_timer(struct vtimer_list *timer)
309{
310 timer->function = NULL;
311 INIT_LIST_HEAD(&timer->entry);
312}
313EXPORT_SYMBOL(init_virt_timer);
314
315static inline int vtimer_pending(struct vtimer_list *timer)
316{
317 return !list_empty(&timer->entry);
318}
319
320static void internal_add_vtimer(struct vtimer_list *timer)
321{
322 if (list_empty(&virt_timer_list)) {
323 /* First timer, just program it. */
324 atomic64_set(&virt_timer_current, timer->expires);
325 atomic64_set(&virt_timer_elapsed, 0);
326 list_add(&timer->entry, &virt_timer_list);
327 } else {
328 /* Update timer against current base. */
329 timer->expires += atomic64_read(&virt_timer_elapsed);
330 if (likely((s64) timer->expires <
331 (s64) atomic64_read(&virt_timer_current)))
332 /* The new timer expires before the current timer. */
333 atomic64_set(&virt_timer_current, timer->expires);
334 /* Insert new timer into the list. */
335 list_add_sorted(timer, &virt_timer_list);
336 }
337}
338
339static void __add_vtimer(struct vtimer_list *timer, int periodic)
340{
341 unsigned long flags;
342
343 timer->interval = periodic ? timer->expires : 0;
344 spin_lock_irqsave(&virt_timer_lock, flags);
345 internal_add_vtimer(timer);
346 spin_unlock_irqrestore(&virt_timer_lock, flags);
347}
348
349/*
350 * add_virt_timer - add a oneshot virtual CPU timer
351 */
352void add_virt_timer(struct vtimer_list *timer)
353{
354 __add_vtimer(timer, 0);
355}
356EXPORT_SYMBOL(add_virt_timer);
357
358/*
359 * add_virt_timer_int - add an interval virtual CPU timer
360 */
361void add_virt_timer_periodic(struct vtimer_list *timer)
362{
363 __add_vtimer(timer, 1);
364}
365EXPORT_SYMBOL(add_virt_timer_periodic);
366
367static int __mod_vtimer(struct vtimer_list *timer, u64 expires, int periodic)
368{
369 unsigned long flags;
370 int rc;
371
372 BUG_ON(!timer->function);
373
374 if (timer->expires == expires && vtimer_pending(timer))
375 return 1;
376 spin_lock_irqsave(&virt_timer_lock, flags);
377 rc = vtimer_pending(timer);
378 if (rc)
379 list_del_init(&timer->entry);
380 timer->interval = periodic ? expires : 0;
381 timer->expires = expires;
382 internal_add_vtimer(timer);
383 spin_unlock_irqrestore(&virt_timer_lock, flags);
384 return rc;
385}
386
387/*
388 * returns whether it has modified a pending timer (1) or not (0)
389 */
390int mod_virt_timer(struct vtimer_list *timer, u64 expires)
391{
392 return __mod_vtimer(timer, expires, 0);
393}
394EXPORT_SYMBOL(mod_virt_timer);
395
396/*
397 * returns whether it has modified a pending timer (1) or not (0)
398 */
399int mod_virt_timer_periodic(struct vtimer_list *timer, u64 expires)
400{
401 return __mod_vtimer(timer, expires, 1);
402}
403EXPORT_SYMBOL(mod_virt_timer_periodic);
404
405/*
406 * Delete a virtual timer.
407 *
408 * returns whether the deleted timer was pending (1) or not (0)
409 */
410int del_virt_timer(struct vtimer_list *timer)
411{
412 unsigned long flags;
413
414 if (!vtimer_pending(timer))
415 return 0;
416 spin_lock_irqsave(&virt_timer_lock, flags);
417 list_del_init(&timer->entry);
418 spin_unlock_irqrestore(&virt_timer_lock, flags);
419 return 1;
420}
421EXPORT_SYMBOL(del_virt_timer);
422
423/*
424 * Start the virtual CPU timer on the current CPU.
425 */
426void vtime_init(void)
427{
428 /* set initial cpu timer */
429 set_vtimer(VTIMER_MAX_SLICE);
430 /* Setup initial MT scaling values */
431 if (smp_cpu_mtid) {
432 __this_cpu_write(mt_scaling_jiffies, jiffies);
433 __this_cpu_write(mt_scaling_mult, 1);
434 __this_cpu_write(mt_scaling_div, 1);
435 stcctm5(smp_cpu_mtid + 1, this_cpu_ptr(mt_cycles));
436 }
437}