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