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