[CELL] spufs: Remove spurious WARN_ON for spu_deactivate for NOSCHED contexts
[linux-2.6-block.git] / arch / powerpc / platforms / cell / spufs / sched.c
CommitLineData
8b3d6663
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1/* sched.c - SPU scheduler.
2 *
3 * Copyright (C) IBM 2005
4 * Author: Mark Nutter <mnutter@us.ibm.com>
5 *
a68cf983 6 * 2006-03-31 NUMA domains added.
8b3d6663
AB
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2, or (at your option)
11 * any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 */
22
3b3d22cb
AB
23#undef DEBUG
24
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25#include <linux/module.h>
26#include <linux/errno.h>
27#include <linux/sched.h>
28#include <linux/kernel.h>
29#include <linux/mm.h>
30#include <linux/completion.h>
31#include <linux/vmalloc.h>
32#include <linux/smp.h>
8b3d6663
AB
33#include <linux/stddef.h>
34#include <linux/unistd.h>
a68cf983
MN
35#include <linux/numa.h>
36#include <linux/mutex.h>
86767277 37#include <linux/notifier.h>
37901802 38#include <linux/kthread.h>
65de66f0
CH
39#include <linux/pid_namespace.h>
40#include <linux/proc_fs.h>
41#include <linux/seq_file.h>
8b3d6663
AB
42
43#include <asm/io.h>
44#include <asm/mmu_context.h>
45#include <asm/spu.h>
46#include <asm/spu_csa.h>
a91942ae 47#include <asm/spu_priv1.h>
8b3d6663
AB
48#include "spufs.h"
49
8b3d6663 50struct spu_prio_array {
72cb3608 51 DECLARE_BITMAP(bitmap, MAX_PRIO);
079cdb61
CH
52 struct list_head runq[MAX_PRIO];
53 spinlock_t runq_lock;
a68cf983
MN
54 struct list_head active_list[MAX_NUMNODES];
55 struct mutex active_mutex[MAX_NUMNODES];
65de66f0
CH
56 int nr_active[MAX_NUMNODES];
57 int nr_waiting;
8b3d6663
AB
58};
59
65de66f0 60static unsigned long spu_avenrun[3];
a68cf983 61static struct spu_prio_array *spu_prio;
37901802
CH
62static struct task_struct *spusched_task;
63static struct timer_list spusched_timer;
8b3d6663 64
fe443ef2
CH
65/*
66 * Priority of a normal, non-rt, non-niced'd process (aka nice level 0).
67 */
68#define NORMAL_PRIO 120
69
70/*
71 * Frequency of the spu scheduler tick. By default we do one SPU scheduler
72 * tick for every 10 CPU scheduler ticks.
73 */
74#define SPUSCHED_TICK (10)
75
76/*
77 * These are the 'tuning knobs' of the scheduler:
78 *
60e24239
JK
79 * Minimum timeslice is 5 msecs (or 1 spu scheduler tick, whichever is
80 * larger), default timeslice is 100 msecs, maximum timeslice is 800 msecs.
fe443ef2 81 */
60e24239
JK
82#define MIN_SPU_TIMESLICE max(5 * HZ / (1000 * SPUSCHED_TICK), 1)
83#define DEF_SPU_TIMESLICE (100 * HZ / (1000 * SPUSCHED_TICK))
fe443ef2
CH
84
85#define MAX_USER_PRIO (MAX_PRIO - MAX_RT_PRIO)
86#define SCALE_PRIO(x, prio) \
87 max(x * (MAX_PRIO - prio) / (MAX_USER_PRIO / 2), MIN_SPU_TIMESLICE)
88
89/*
90 * scale user-nice values [ -20 ... 0 ... 19 ] to time slice values:
91 * [800ms ... 100ms ... 5ms]
92 *
93 * The higher a thread's priority, the bigger timeslices
94 * it gets during one round of execution. But even the lowest
95 * priority thread gets MIN_TIMESLICE worth of execution time.
96 */
97void spu_set_timeslice(struct spu_context *ctx)
98{
99 if (ctx->prio < NORMAL_PRIO)
100 ctx->time_slice = SCALE_PRIO(DEF_SPU_TIMESLICE * 4, ctx->prio);
101 else
102 ctx->time_slice = SCALE_PRIO(DEF_SPU_TIMESLICE, ctx->prio);
103}
104
2cf2b3b4
CH
105/*
106 * Update scheduling information from the owning thread.
107 */
108void __spu_update_sched_info(struct spu_context *ctx)
109{
476273ad
CH
110 /*
111 * 32-Bit assignment are atomic on powerpc, and we don't care about
112 * memory ordering here because retriving the controlling thread is
113 * per defintion racy.
114 */
115 ctx->tid = current->pid;
116
2cf2b3b4
CH
117 /*
118 * We do our own priority calculations, so we normally want
119 * ->static_prio to start with. Unfortunately thies field
120 * contains junk for threads with a realtime scheduling
121 * policy so we have to look at ->prio in this case.
122 */
123 if (rt_prio(current->prio))
124 ctx->prio = current->prio;
125 else
126 ctx->prio = current->static_prio;
127 ctx->policy = current->policy;
ea1ae594
CH
128
129 /*
130 * A lot of places that don't hold active_mutex poke into
131 * cpus_allowed, including grab_runnable_context which
132 * already holds the runq_lock. So abuse runq_lock
133 * to protect this field aswell.
134 */
135 spin_lock(&spu_prio->runq_lock);
136 ctx->cpus_allowed = current->cpus_allowed;
137 spin_unlock(&spu_prio->runq_lock);
2cf2b3b4
CH
138}
139
140void spu_update_sched_info(struct spu_context *ctx)
141{
142 int node = ctx->spu->node;
143
144 mutex_lock(&spu_prio->active_mutex[node]);
145 __spu_update_sched_info(ctx);
146 mutex_unlock(&spu_prio->active_mutex[node]);
147}
148
ea1ae594 149static int __node_allowed(struct spu_context *ctx, int node)
8b3d6663 150{
ea1ae594
CH
151 if (nr_cpus_node(node)) {
152 cpumask_t mask = node_to_cpumask(node);
8b3d6663 153
ea1ae594
CH
154 if (cpus_intersects(mask, ctx->cpus_allowed))
155 return 1;
156 }
157
158 return 0;
159}
160
161static int node_allowed(struct spu_context *ctx, int node)
162{
163 int rval;
164
165 spin_lock(&spu_prio->runq_lock);
166 rval = __node_allowed(ctx, node);
167 spin_unlock(&spu_prio->runq_lock);
168
169 return rval;
8b3d6663
AB
170}
171
202557d2
CH
172/**
173 * spu_add_to_active_list - add spu to active list
174 * @spu: spu to add to the active list
175 */
176static void spu_add_to_active_list(struct spu *spu)
177{
65de66f0
CH
178 int node = spu->node;
179
180 mutex_lock(&spu_prio->active_mutex[node]);
181 spu_prio->nr_active[node]++;
182 list_add_tail(&spu->list, &spu_prio->active_list[node]);
183 mutex_unlock(&spu_prio->active_mutex[node]);
202557d2
CH
184}
185
37901802
CH
186static void __spu_remove_from_active_list(struct spu *spu)
187{
188 list_del_init(&spu->list);
65de66f0 189 spu_prio->nr_active[spu->node]--;
37901802
CH
190}
191
202557d2
CH
192/**
193 * spu_remove_from_active_list - remove spu from active list
194 * @spu: spu to remove from the active list
202557d2 195 */
678b2ff1 196static void spu_remove_from_active_list(struct spu *spu)
202557d2
CH
197{
198 int node = spu->node;
202557d2
CH
199
200 mutex_lock(&spu_prio->active_mutex[node]);
37901802 201 __spu_remove_from_active_list(spu);
202557d2 202 mutex_unlock(&spu_prio->active_mutex[node]);
202557d2
CH
203}
204
86767277
AB
205static BLOCKING_NOTIFIER_HEAD(spu_switch_notifier);
206
207static void spu_switch_notify(struct spu *spu, struct spu_context *ctx)
208{
209 blocking_notifier_call_chain(&spu_switch_notifier,
210 ctx ? ctx->object_id : 0, spu);
211}
212
213int spu_switch_event_register(struct notifier_block * n)
214{
215 return blocking_notifier_chain_register(&spu_switch_notifier, n);
216}
217
218int spu_switch_event_unregister(struct notifier_block * n)
219{
220 return blocking_notifier_chain_unregister(&spu_switch_notifier, n);
221}
222
202557d2
CH
223/**
224 * spu_bind_context - bind spu context to physical spu
225 * @spu: physical spu to bind to
226 * @ctx: context to bind
227 */
228static void spu_bind_context(struct spu *spu, struct spu_context *ctx)
8b3d6663 229{
a68cf983
MN
230 pr_debug("%s: pid=%d SPU=%d NODE=%d\n", __FUNCTION__, current->pid,
231 spu->number, spu->node);
e9f8a0b6
CH
232
233 ctx->stats.slb_flt_base = spu->stats.slb_flt;
234 ctx->stats.class2_intr_base = spu->stats.class2_intr;
235
8b3d6663
AB
236 spu->ctx = ctx;
237 spu->flags = 0;
238 ctx->spu = spu;
239 ctx->ops = &spu_hw_ops;
240 spu->pid = current->pid;
94b2a439 241 spu_associate_mm(spu, ctx->owner);
8b3d6663
AB
242 spu->ibox_callback = spufs_ibox_callback;
243 spu->wbox_callback = spufs_wbox_callback;
5110459f 244 spu->stop_callback = spufs_stop_callback;
a33a7d73 245 spu->mfc_callback = spufs_mfc_callback;
9add11da 246 spu->dma_callback = spufs_dma_callback;
8b3d6663 247 mb();
5110459f 248 spu_unmap_mappings(ctx);
8b3d6663 249 spu_restore(&ctx->csa, spu);
2a911f0b 250 spu->timestamp = jiffies;
a68cf983 251 spu_cpu_affinity_set(spu, raw_smp_processor_id());
86767277 252 spu_switch_notify(spu, ctx);
81998baf 253 ctx->state = SPU_STATE_RUNNABLE;
fe2f896d 254 spu_switch_state(spu, SPU_UTIL_SYSTEM);
8b3d6663
AB
255}
256
202557d2
CH
257/**
258 * spu_unbind_context - unbind spu context from physical spu
259 * @spu: physical spu to unbind from
260 * @ctx: context to unbind
202557d2 261 */
678b2ff1 262static void spu_unbind_context(struct spu *spu, struct spu_context *ctx)
8b3d6663 263{
a68cf983
MN
264 pr_debug("%s: unbind pid=%d SPU=%d NODE=%d\n", __FUNCTION__,
265 spu->pid, spu->number, spu->node);
202557d2 266
fe2f896d
CH
267 spu_switch_state(spu, SPU_UTIL_IDLE);
268
86767277 269 spu_switch_notify(spu, NULL);
5110459f 270 spu_unmap_mappings(ctx);
8b3d6663 271 spu_save(&ctx->csa, spu);
2a911f0b 272 spu->timestamp = jiffies;
8b3d6663
AB
273 ctx->state = SPU_STATE_SAVED;
274 spu->ibox_callback = NULL;
275 spu->wbox_callback = NULL;
5110459f 276 spu->stop_callback = NULL;
a33a7d73 277 spu->mfc_callback = NULL;
9add11da 278 spu->dma_callback = NULL;
94b2a439 279 spu_associate_mm(spu, NULL);
8b3d6663 280 spu->pid = 0;
8b3d6663
AB
281 ctx->ops = &spu_backing_ops;
282 ctx->spu = NULL;
2a911f0b 283 spu->flags = 0;
8b3d6663 284 spu->ctx = NULL;
e9f8a0b6
CH
285
286 ctx->stats.slb_flt +=
287 (spu->stats.slb_flt - ctx->stats.slb_flt_base);
288 ctx->stats.class2_intr +=
289 (spu->stats.class2_intr - ctx->stats.class2_intr_base);
8b3d6663
AB
290}
291
079cdb61
CH
292/**
293 * spu_add_to_rq - add a context to the runqueue
294 * @ctx: context to add
295 */
4e0f4ed0 296static void __spu_add_to_rq(struct spu_context *ctx)
8b3d6663 297{
27449971
CH
298 /*
299 * Unfortunately this code path can be called from multiple threads
300 * on behalf of a single context due to the way the problem state
301 * mmap support works.
302 *
303 * Fortunately we need to wake up all these threads at the same time
304 * and can simply skip the runqueue addition for every but the first
305 * thread getting into this codepath.
306 *
307 * It's still quite hacky, and long-term we should proxy all other
308 * threads through the owner thread so that spu_run is in control
309 * of all the scheduling activity for a given context.
310 */
311 if (list_empty(&ctx->rq)) {
312 list_add_tail(&ctx->rq, &spu_prio->runq[ctx->prio]);
313 set_bit(ctx->prio, spu_prio->bitmap);
314 if (!spu_prio->nr_waiting++)
315 __mod_timer(&spusched_timer, jiffies + SPUSCHED_TICK);
316 }
2a911f0b 317}
5110459f 318
4e0f4ed0 319static void __spu_del_from_rq(struct spu_context *ctx)
a475c2f4 320{
4e0f4ed0
LB
321 int prio = ctx->prio;
322
65de66f0 323 if (!list_empty(&ctx->rq)) {
c77239b8
CH
324 if (!--spu_prio->nr_waiting)
325 del_timer(&spusched_timer);
a475c2f4 326 list_del_init(&ctx->rq);
c77239b8
CH
327
328 if (list_empty(&spu_prio->runq[prio]))
329 clear_bit(prio, spu_prio->bitmap);
65de66f0 330 }
079cdb61 331}
a68cf983 332
079cdb61 333static void spu_prio_wait(struct spu_context *ctx)
8b3d6663 334{
a68cf983 335 DEFINE_WAIT(wait);
8b3d6663 336
4e0f4ed0 337 spin_lock(&spu_prio->runq_lock);
079cdb61 338 prepare_to_wait_exclusive(&ctx->stop_wq, &wait, TASK_INTERRUPTIBLE);
a68cf983 339 if (!signal_pending(current)) {
4e0f4ed0
LB
340 __spu_add_to_rq(ctx);
341 spin_unlock(&spu_prio->runq_lock);
650f8b02 342 mutex_unlock(&ctx->state_mutex);
a68cf983 343 schedule();
650f8b02 344 mutex_lock(&ctx->state_mutex);
4e0f4ed0
LB
345 spin_lock(&spu_prio->runq_lock);
346 __spu_del_from_rq(ctx);
8b3d6663 347 }
4e0f4ed0 348 spin_unlock(&spu_prio->runq_lock);
079cdb61
CH
349 __set_current_state(TASK_RUNNING);
350 remove_wait_queue(&ctx->stop_wq, &wait);
8b3d6663
AB
351}
352
079cdb61 353static struct spu *spu_get_idle(struct spu_context *ctx)
a68cf983
MN
354{
355 struct spu *spu = NULL;
356 int node = cpu_to_node(raw_smp_processor_id());
357 int n;
358
359 for (n = 0; n < MAX_NUMNODES; n++, node++) {
360 node = (node < MAX_NUMNODES) ? node : 0;
ea1ae594 361 if (!node_allowed(ctx, node))
a68cf983
MN
362 continue;
363 spu = spu_alloc_node(node);
364 if (spu)
365 break;
366 }
367 return spu;
368}
8b3d6663 369
52f04fcf
CH
370/**
371 * find_victim - find a lower priority context to preempt
372 * @ctx: canidate context for running
373 *
374 * Returns the freed physical spu to run the new context on.
375 */
376static struct spu *find_victim(struct spu_context *ctx)
377{
378 struct spu_context *victim = NULL;
379 struct spu *spu;
380 int node, n;
381
382 /*
383 * Look for a possible preemption candidate on the local node first.
384 * If there is no candidate look at the other nodes. This isn't
385 * exactly fair, but so far the whole spu schedule tries to keep
386 * a strong node affinity. We might want to fine-tune this in
387 * the future.
388 */
389 restart:
390 node = cpu_to_node(raw_smp_processor_id());
391 for (n = 0; n < MAX_NUMNODES; n++, node++) {
392 node = (node < MAX_NUMNODES) ? node : 0;
ea1ae594 393 if (!node_allowed(ctx, node))
52f04fcf
CH
394 continue;
395
396 mutex_lock(&spu_prio->active_mutex[node]);
397 list_for_each_entry(spu, &spu_prio->active_list[node], list) {
398 struct spu_context *tmp = spu->ctx;
399
fe443ef2
CH
400 if (tmp->prio > ctx->prio &&
401 (!victim || tmp->prio > victim->prio))
52f04fcf
CH
402 victim = spu->ctx;
403 }
404 mutex_unlock(&spu_prio->active_mutex[node]);
405
406 if (victim) {
407 /*
408 * This nests ctx->state_mutex, but we always lock
409 * higher priority contexts before lower priority
410 * ones, so this is safe until we introduce
411 * priority inheritance schemes.
412 */
413 if (!mutex_trylock(&victim->state_mutex)) {
414 victim = NULL;
415 goto restart;
416 }
417
418 spu = victim->spu;
419 if (!spu) {
420 /*
421 * This race can happen because we've dropped
422 * the active list mutex. No a problem, just
423 * restart the search.
424 */
425 mutex_unlock(&victim->state_mutex);
426 victim = NULL;
427 goto restart;
428 }
37901802 429 spu_remove_from_active_list(spu);
52f04fcf 430 spu_unbind_context(spu, victim);
e9f8a0b6 431 victim->stats.invol_ctx_switch++;
fe2f896d 432 spu->stats.invol_ctx_switch++;
52f04fcf 433 mutex_unlock(&victim->state_mutex);
e097b513
CH
434 /*
435 * We need to break out of the wait loop in spu_run
436 * manually to ensure this context gets put on the
437 * runqueue again ASAP.
438 */
439 wake_up(&victim->stop_wq);
52f04fcf
CH
440 return spu;
441 }
442 }
443
444 return NULL;
445}
446
079cdb61
CH
447/**
448 * spu_activate - find a free spu for a context and execute it
449 * @ctx: spu context to schedule
450 * @flags: flags (currently ignored)
451 *
08873095 452 * Tries to find a free spu to run @ctx. If no free spu is available
079cdb61
CH
453 * add the context to the runqueue so it gets woken up once an spu
454 * is available.
455 */
26bec673 456int spu_activate(struct spu_context *ctx, unsigned long flags)
8b3d6663 457{
e9f8a0b6 458 spuctx_switch_state(ctx, SPUCTX_UTIL_SYSTEM);
8b3d6663 459
079cdb61
CH
460 do {
461 struct spu *spu;
462
27449971
CH
463 /*
464 * If there are multiple threads waiting for a single context
465 * only one actually binds the context while the others will
466 * only be able to acquire the state_mutex once the context
467 * already is in runnable state.
468 */
469 if (ctx->spu)
470 return 0;
471
079cdb61 472 spu = spu_get_idle(ctx);
52f04fcf
CH
473 /*
474 * If this is a realtime thread we try to get it running by
475 * preempting a lower priority thread.
476 */
fe443ef2 477 if (!spu && rt_prio(ctx->prio))
52f04fcf 478 spu = find_victim(ctx);
079cdb61 479 if (spu) {
202557d2 480 spu_bind_context(spu, ctx);
37901802 481 spu_add_to_active_list(spu);
079cdb61 482 return 0;
a68cf983 483 }
079cdb61 484
50b520d4 485 spu_prio_wait(ctx);
079cdb61
CH
486 } while (!signal_pending(current));
487
488 return -ERESTARTSYS;
8b3d6663
AB
489}
490
bb5db29a
CH
491/**
492 * grab_runnable_context - try to find a runnable context
493 *
494 * Remove the highest priority context on the runqueue and return it
495 * to the caller. Returns %NULL if no runnable context was found.
496 */
ea1ae594 497static struct spu_context *grab_runnable_context(int prio, int node)
bb5db29a 498{
ea1ae594 499 struct spu_context *ctx;
bb5db29a
CH
500 int best;
501
502 spin_lock(&spu_prio->runq_lock);
503 best = sched_find_first_bit(spu_prio->bitmap);
ea1ae594 504 while (best < prio) {
bb5db29a
CH
505 struct list_head *rq = &spu_prio->runq[best];
506
ea1ae594
CH
507 list_for_each_entry(ctx, rq, rq) {
508 /* XXX(hch): check for affinity here aswell */
509 if (__node_allowed(ctx, node)) {
510 __spu_del_from_rq(ctx);
511 goto found;
512 }
513 }
514 best++;
bb5db29a 515 }
ea1ae594
CH
516 ctx = NULL;
517 found:
bb5db29a 518 spin_unlock(&spu_prio->runq_lock);
bb5db29a
CH
519 return ctx;
520}
521
522static int __spu_deactivate(struct spu_context *ctx, int force, int max_prio)
523{
524 struct spu *spu = ctx->spu;
525 struct spu_context *new = NULL;
526
527 if (spu) {
ea1ae594 528 new = grab_runnable_context(max_prio, spu->node);
bb5db29a 529 if (new || force) {
37901802 530 spu_remove_from_active_list(spu);
bb5db29a 531 spu_unbind_context(spu, ctx);
e9f8a0b6 532 ctx->stats.vol_ctx_switch++;
fe2f896d 533 spu->stats.vol_ctx_switch++;
bb5db29a
CH
534 spu_free(spu);
535 if (new)
536 wake_up(&new->stop_wq);
537 }
538
539 }
540
541 return new != NULL;
542}
543
678b2ff1
CH
544/**
545 * spu_deactivate - unbind a context from it's physical spu
546 * @ctx: spu context to unbind
547 *
548 * Unbind @ctx from the physical spu it is running on and schedule
549 * the highest priority context to run on the freed physical spu.
550 */
8b3d6663
AB
551void spu_deactivate(struct spu_context *ctx)
552{
bb5db29a 553 __spu_deactivate(ctx, 1, MAX_PRIO);
e9f8a0b6 554 spuctx_switch_state(ctx, SPUCTX_UTIL_USER);
8b3d6663
AB
555}
556
ae7b4c52
CH
557/**
558 * spu_yield - yield a physical spu if others are waiting
559 * @ctx: spu context to yield
560 *
561 * Check if there is a higher priority context waiting and if yes
562 * unbind @ctx from the physical spu and schedule the highest
563 * priority context to run on the freed physical spu instead.
564 */
8b3d6663
AB
565void spu_yield(struct spu_context *ctx)
566{
e5c0b9ec
CH
567 if (!(ctx->flags & SPU_CREATE_NOSCHED)) {
568 mutex_lock(&ctx->state_mutex);
e9f8a0b6
CH
569 if (__spu_deactivate(ctx, 0, MAX_PRIO))
570 spuctx_switch_state(ctx, SPUCTX_UTIL_USER);
fe2f896d 571 else {
e9f8a0b6 572 spuctx_switch_state(ctx, SPUCTX_UTIL_LOADED);
fe2f896d
CH
573 spu_switch_state(ctx->spu, SPU_UTIL_USER);
574 }
e5c0b9ec
CH
575 mutex_unlock(&ctx->state_mutex);
576 }
bb5db29a 577}
8b3d6663 578
37901802 579static void spusched_tick(struct spu_context *ctx)
bb5db29a 580{
df09cf3e
CH
581 if (ctx->flags & SPU_CREATE_NOSCHED)
582 return;
583 if (ctx->policy == SCHED_FIFO)
584 return;
585
586 if (--ctx->time_slice)
37901802 587 return;
bb5db29a
CH
588
589 /*
37901802
CH
590 * Unfortunately active_mutex ranks outside of state_mutex, so
591 * we have to trylock here. If we fail give the context another
592 * tick and try again.
bb5db29a 593 */
37901802 594 if (mutex_trylock(&ctx->state_mutex)) {
7022543e 595 struct spu *spu = ctx->spu;
ea1ae594
CH
596 struct spu_context *new;
597
598 new = grab_runnable_context(ctx->prio + 1, spu->node);
37901802 599 if (new) {
bb5db29a 600
37901802
CH
601 __spu_remove_from_active_list(spu);
602 spu_unbind_context(spu, ctx);
e9f8a0b6 603 ctx->stats.invol_ctx_switch++;
fe2f896d 604 spu->stats.invol_ctx_switch++;
37901802
CH
605 spu_free(spu);
606 wake_up(&new->stop_wq);
607 /*
608 * We need to break out of the wait loop in
609 * spu_run manually to ensure this context
610 * gets put on the runqueue again ASAP.
611 */
612 wake_up(&ctx->stop_wq);
613 }
fe443ef2 614 spu_set_timeslice(ctx);
37901802 615 mutex_unlock(&ctx->state_mutex);
bb5db29a 616 } else {
37901802 617 ctx->time_slice++;
8b3d6663 618 }
8b3d6663
AB
619}
620
65de66f0
CH
621/**
622 * count_active_contexts - count nr of active tasks
623 *
624 * Return the number of tasks currently running or waiting to run.
625 *
626 * Note that we don't take runq_lock / active_mutex here. Reading
627 * a single 32bit value is atomic on powerpc, and we don't care
628 * about memory ordering issues here.
629 */
630static unsigned long count_active_contexts(void)
631{
632 int nr_active = 0, node;
633
634 for (node = 0; node < MAX_NUMNODES; node++)
635 nr_active += spu_prio->nr_active[node];
636 nr_active += spu_prio->nr_waiting;
637
638 return nr_active;
639}
640
641/**
642 * spu_calc_load - given tick count, update the avenrun load estimates.
643 * @tick: tick count
644 *
645 * No locking against reading these values from userspace, as for
646 * the CPU loadavg code.
647 */
648static void spu_calc_load(unsigned long ticks)
649{
650 unsigned long active_tasks; /* fixed-point */
651 static int count = LOAD_FREQ;
652
653 count -= ticks;
654
655 if (unlikely(count < 0)) {
656 active_tasks = count_active_contexts() * FIXED_1;
657 do {
658 CALC_LOAD(spu_avenrun[0], EXP_1, active_tasks);
659 CALC_LOAD(spu_avenrun[1], EXP_5, active_tasks);
660 CALC_LOAD(spu_avenrun[2], EXP_15, active_tasks);
661 count += LOAD_FREQ;
662 } while (count < 0);
663 }
664}
665
37901802
CH
666static void spusched_wake(unsigned long data)
667{
668 mod_timer(&spusched_timer, jiffies + SPUSCHED_TICK);
669 wake_up_process(spusched_task);
65de66f0 670 spu_calc_load(SPUSCHED_TICK);
37901802
CH
671}
672
673static int spusched_thread(void *unused)
674{
675 struct spu *spu, *next;
676 int node;
677
37901802
CH
678 while (!kthread_should_stop()) {
679 set_current_state(TASK_INTERRUPTIBLE);
680 schedule();
681 for (node = 0; node < MAX_NUMNODES; node++) {
682 mutex_lock(&spu_prio->active_mutex[node]);
683 list_for_each_entry_safe(spu, next,
684 &spu_prio->active_list[node],
685 list)
686 spusched_tick(spu->ctx);
687 mutex_unlock(&spu_prio->active_mutex[node]);
688 }
689 }
690
37901802
CH
691 return 0;
692}
693
65de66f0
CH
694#define LOAD_INT(x) ((x) >> FSHIFT)
695#define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
696
697static int show_spu_loadavg(struct seq_file *s, void *private)
698{
699 int a, b, c;
700
701 a = spu_avenrun[0] + (FIXED_1/200);
702 b = spu_avenrun[1] + (FIXED_1/200);
703 c = spu_avenrun[2] + (FIXED_1/200);
704
705 /*
706 * Note that last_pid doesn't really make much sense for the
707 * SPU loadavg (it even seems very odd on the CPU side..),
708 * but we include it here to have a 100% compatible interface.
709 */
710 seq_printf(s, "%d.%02d %d.%02d %d.%02d %ld/%d %d\n",
711 LOAD_INT(a), LOAD_FRAC(a),
712 LOAD_INT(b), LOAD_FRAC(b),
713 LOAD_INT(c), LOAD_FRAC(c),
714 count_active_contexts(),
715 atomic_read(&nr_spu_contexts),
716 current->nsproxy->pid_ns->last_pid);
717 return 0;
718}
719
720static int spu_loadavg_open(struct inode *inode, struct file *file)
721{
722 return single_open(file, show_spu_loadavg, NULL);
723}
724
725static const struct file_operations spu_loadavg_fops = {
726 .open = spu_loadavg_open,
727 .read = seq_read,
728 .llseek = seq_lseek,
729 .release = single_release,
730};
731
8b3d6663
AB
732int __init spu_sched_init(void)
733{
65de66f0
CH
734 struct proc_dir_entry *entry;
735 int err = -ENOMEM, i;
8b3d6663 736
a68cf983 737 spu_prio = kzalloc(sizeof(struct spu_prio_array), GFP_KERNEL);
37901802 738 if (!spu_prio)
65de66f0 739 goto out;
37901802 740
8b3d6663 741 for (i = 0; i < MAX_PRIO; i++) {
079cdb61 742 INIT_LIST_HEAD(&spu_prio->runq[i]);
a68cf983 743 __clear_bit(i, spu_prio->bitmap);
8b3d6663 744 }
a68cf983
MN
745 __set_bit(MAX_PRIO, spu_prio->bitmap);
746 for (i = 0; i < MAX_NUMNODES; i++) {
747 mutex_init(&spu_prio->active_mutex[i]);
748 INIT_LIST_HEAD(&spu_prio->active_list[i]);
8b3d6663 749 }
079cdb61 750 spin_lock_init(&spu_prio->runq_lock);
37901802 751
c77239b8
CH
752 setup_timer(&spusched_timer, spusched_wake, 0);
753
37901802
CH
754 spusched_task = kthread_run(spusched_thread, NULL, "spusched");
755 if (IS_ERR(spusched_task)) {
65de66f0
CH
756 err = PTR_ERR(spusched_task);
757 goto out_free_spu_prio;
37901802 758 }
f3f59bec 759
65de66f0
CH
760 entry = create_proc_entry("spu_loadavg", 0, NULL);
761 if (!entry)
762 goto out_stop_kthread;
763 entry->proc_fops = &spu_loadavg_fops;
764
f3f59bec
JK
765 pr_debug("spusched: tick: %d, min ticks: %d, default ticks: %d\n",
766 SPUSCHED_TICK, MIN_SPU_TIMESLICE, DEF_SPU_TIMESLICE);
8b3d6663 767 return 0;
37901802 768
65de66f0
CH
769 out_stop_kthread:
770 kthread_stop(spusched_task);
771 out_free_spu_prio:
772 kfree(spu_prio);
773 out:
774 return err;
8b3d6663
AB
775}
776
d1450317 777void spu_sched_exit(void)
8b3d6663 778{
a68cf983
MN
779 struct spu *spu, *tmp;
780 int node;
781
65de66f0
CH
782 remove_proc_entry("spu_loadavg", NULL);
783
c77239b8 784 del_timer_sync(&spusched_timer);
37901802
CH
785 kthread_stop(spusched_task);
786
a68cf983
MN
787 for (node = 0; node < MAX_NUMNODES; node++) {
788 mutex_lock(&spu_prio->active_mutex[node]);
789 list_for_each_entry_safe(spu, tmp, &spu_prio->active_list[node],
790 list) {
791 list_del_init(&spu->list);
792 spu_free(spu);
793 }
794 mutex_unlock(&spu_prio->active_mutex[node]);
8b3d6663 795 }
a68cf983 796 kfree(spu_prio);
8b3d6663 797}