/arch/powerpc/platforms/cell/spufs/context.c

  1/*
  2 * SPU file system -- SPU context management
  3 *
  4 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
  5 *
  6 * Author: Arnd Bergmann <arndb@de.ibm.com>
  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
 23#include <linux/fs.h>
 24#include <linux/mm.h>
 25#include <linux/module.h>
 26#include <linux/slab.h>
 27#include <asm/atomic.h>
 28#include <asm/spu.h>
 29#include <asm/spu_csa.h>
 30#include "spufs.h"
 31#include "sputrace.h"
 32
 33
 34atomic_t nr_spu_contexts = ATOMIC_INIT(0);
 35
 36struct spu_context *alloc_spu_context(struct spu_gang *gang)
 37{
 38	struct spu_context *ctx;
 39	struct timespec ts;
 40
 41	ctx = kzalloc(sizeof *ctx, GFP_KERNEL);
 42	if (!ctx)
 43		goto out;
 44	/* Binding to physical processor deferred
 45	 * until spu_activate().
 46	 */
 47	if (spu_init_csa(&ctx->csa))
 48		goto out_free;
 49	spin_lock_init(&ctx->mmio_lock);
 50	mutex_init(&ctx->mapping_lock);
 51	kref_init(&ctx->kref);
 52	mutex_init(&ctx->state_mutex);
 53	mutex_init(&ctx->run_mutex);
 54	init_waitqueue_head(&ctx->ibox_wq);
 55	init_waitqueue_head(&ctx->wbox_wq);
 56	init_waitqueue_head(&ctx->stop_wq);
 57	init_waitqueue_head(&ctx->mfc_wq);
 58	init_waitqueue_head(&ctx->run_wq);
 59	ctx->state = SPU_STATE_SAVED;
 60	ctx->ops = &spu_backing_ops;
 61	ctx->owner = get_task_mm(current);
 62	INIT_LIST_HEAD(&ctx->rq);
 63	INIT_LIST_HEAD(&ctx->aff_list);
 64	if (gang)
 65		spu_gang_add_ctx(gang, ctx);
 66
 67	__spu_update_sched_info(ctx);
 68	spu_set_timeslice(ctx);
 69	ctx->stats.util_state = SPU_UTIL_IDLE_LOADED;
 70	ktime_get_ts(&ts);
 71	ctx->stats.tstamp = timespec_to_ns(&ts);
 72
 73	atomic_inc(&nr_spu_contexts);
 74	goto out;
 75out_free:
 76	kfree(ctx);
 77	ctx = NULL;
 78out:
 79	return ctx;
 80}
 81
 82void destroy_spu_context(struct kref *kref)
 83{
 84	struct spu_context *ctx;
 85	ctx = container_of(kref, struct spu_context, kref);
 86	spu_context_nospu_trace(destroy_spu_context__enter, ctx);
 87	mutex_lock(&ctx->state_mutex);
 88	spu_deactivate(ctx);
 89	mutex_unlock(&ctx->state_mutex);
 90	spu_fini_csa(&ctx->csa);
 91	if (ctx->gang)
 92		spu_gang_remove_ctx(ctx->gang, ctx);
 93	if (ctx->prof_priv_kref)
 94		kref_put(ctx->prof_priv_kref, ctx->prof_priv_release);
 95	BUG_ON(!list_empty(&ctx->rq));
 96	atomic_dec(&nr_spu_contexts);
 97	kfree(ctx->switch_log);
 98	kfree(ctx);
 99}
100
101struct spu_context * get_spu_context(struct spu_context *ctx)
102{
103	kref_get(&ctx->kref);
104	return ctx;
105}
106
107int put_spu_context(struct spu_context *ctx)
108{
109	return kref_put(&ctx->kref, &destroy_spu_context);
110}
111
112/* give up the mm reference when the context is about to be destroyed */
113void spu_forget(struct spu_context *ctx)
114{
115	struct mm_struct *mm;
116
117	/*
118	 * This is basically an open-coded spu_acquire_saved, except that
119	 * we don't acquire the state mutex interruptible, and we don't
120	 * want this context to be rescheduled on release.
121	 */
122	mutex_lock(&ctx->state_mutex);
123	if (ctx->state != SPU_STATE_SAVED)
124		spu_deactivate(ctx);
125
126	mm = ctx->owner;
127	ctx->owner = NULL;
128	mmput(mm);
129	spu_release(ctx);
130}
131
132void spu_unmap_mappings(struct spu_context *ctx)
133{
134	mutex_lock(&ctx->mapping_lock);
135	if (ctx->local_store)
136		unmap_mapping_range(ctx->local_store, 0, LS_SIZE, 1);
137	if (ctx->mfc)
138		unmap_mapping_range(ctx->mfc, 0, SPUFS_MFC_MAP_SIZE, 1);
139	if (ctx->cntl)
140		unmap_mapping_range(ctx->cntl, 0, SPUFS_CNTL_MAP_SIZE, 1);
141	if (ctx->signal1)
142		unmap_mapping_range(ctx->signal1, 0, SPUFS_SIGNAL_MAP_SIZE, 1);
143	if (ctx->signal2)
144		unmap_mapping_range(ctx->signal2, 0, SPUFS_SIGNAL_MAP_SIZE, 1);
145	if (ctx->mss)
146		unmap_mapping_range(ctx->mss, 0, SPUFS_MSS_MAP_SIZE, 1);
147	if (ctx->psmap)
148		unmap_mapping_range(ctx->psmap, 0, SPUFS_PS_MAP_SIZE, 1);
149	mutex_unlock(&ctx->mapping_lock);
150}
151
152/**
153 * spu_acquire_saved - lock spu contex and make sure it is in saved state
154 * @ctx:	spu contex to lock
155 */
156int spu_acquire_saved(struct spu_context *ctx)
157{
158	int ret;
159
160	spu_context_nospu_trace(spu_acquire_saved__enter, ctx);
161
162	ret = spu_acquire(ctx);
163	if (ret)
164		return ret;
165
166	if (ctx->state != SPU_STATE_SAVED) {
167		set_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags);
168		spu_deactivate(ctx);
169	}
170
171	return 0;
172}
173
174/**
175 * spu_release_saved - unlock spu context and return it to the runqueue
176 * @ctx:	context to unlock
177 */
178void spu_release_saved(struct spu_context *ctx)
179{
180	BUG_ON(ctx->state != SPU_STATE_SAVED);
181
182	if (test_and_clear_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags) &&
183			test_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags))
184		spu_activate(ctx, 0);
185
186	spu_release(ctx);
187}
188