xref: /linux/arch/powerpc/platforms/cell/spufs/context.c (revision c0c914eca7f251c70facc37dfebeaf176601918d)
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 
34 atomic_t nr_spu_contexts = ATOMIC_INIT(0);
35 
36 struct 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;
73 out_free:
74 	kfree(ctx);
75 	ctx = NULL;
76 out:
77 	return ctx;
78 }
79 
80 void 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 
99 struct spu_context * get_spu_context(struct spu_context *ctx)
100 {
101 	kref_get(&ctx->kref);
102 	return ctx;
103 }
104 
105 int 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 */
111 void 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 
130 void 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  */
154 int 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  */
176 void 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