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 
32 
33 atomic_t nr_spu_contexts = ATOMIC_INIT(0);
34 
35 struct spu_context *alloc_spu_context(struct spu_gang *gang)
36 {
37 	struct spu_context *ctx;
38 	struct timespec ts;
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 	ktime_get_ts(&ts);
70 	ctx->stats.tstamp = timespec_to_ns(&ts);
71 
72 	atomic_inc(&nr_spu_contexts);
73 	goto out;
74 out_free:
75 	kfree(ctx);
76 	ctx = NULL;
77 out:
78 	return ctx;
79 }
80 
81 void destroy_spu_context(struct kref *kref)
82 {
83 	struct spu_context *ctx;
84 	ctx = container_of(kref, struct spu_context, kref);
85 	spu_context_nospu_trace(destroy_spu_context__enter, ctx);
86 	mutex_lock(&ctx->state_mutex);
87 	spu_deactivate(ctx);
88 	mutex_unlock(&ctx->state_mutex);
89 	spu_fini_csa(&ctx->csa);
90 	if (ctx->gang)
91 		spu_gang_remove_ctx(ctx->gang, ctx);
92 	if (ctx->prof_priv_kref)
93 		kref_put(ctx->prof_priv_kref, ctx->prof_priv_release);
94 	BUG_ON(!list_empty(&ctx->rq));
95 	atomic_dec(&nr_spu_contexts);
96 	kfree(ctx->switch_log);
97 	kfree(ctx);
98 }
99 
100 struct spu_context * get_spu_context(struct spu_context *ctx)
101 {
102 	kref_get(&ctx->kref);
103 	return ctx;
104 }
105 
106 int put_spu_context(struct spu_context *ctx)
107 {
108 	return kref_put(&ctx->kref, &destroy_spu_context);
109 }
110 
111 /* give up the mm reference when the context is about to be destroyed */
112 void spu_forget(struct spu_context *ctx)
113 {
114 	struct mm_struct *mm;
115 
116 	/*
117 	 * This is basically an open-coded spu_acquire_saved, except that
118 	 * we don't acquire the state mutex interruptible, and we don't
119 	 * want this context to be rescheduled on release.
120 	 */
121 	mutex_lock(&ctx->state_mutex);
122 	if (ctx->state != SPU_STATE_SAVED)
123 		spu_deactivate(ctx);
124 
125 	mm = ctx->owner;
126 	ctx->owner = NULL;
127 	mmput(mm);
128 	spu_release(ctx);
129 }
130 
131 void spu_unmap_mappings(struct spu_context *ctx)
132 {
133 	mutex_lock(&ctx->mapping_lock);
134 	if (ctx->local_store)
135 		unmap_mapping_range(ctx->local_store, 0, LS_SIZE, 1);
136 	if (ctx->mfc)
137 		unmap_mapping_range(ctx->mfc, 0, SPUFS_MFC_MAP_SIZE, 1);
138 	if (ctx->cntl)
139 		unmap_mapping_range(ctx->cntl, 0, SPUFS_CNTL_MAP_SIZE, 1);
140 	if (ctx->signal1)
141 		unmap_mapping_range(ctx->signal1, 0, SPUFS_SIGNAL_MAP_SIZE, 1);
142 	if (ctx->signal2)
143 		unmap_mapping_range(ctx->signal2, 0, SPUFS_SIGNAL_MAP_SIZE, 1);
144 	if (ctx->mss)
145 		unmap_mapping_range(ctx->mss, 0, SPUFS_MSS_MAP_SIZE, 1);
146 	if (ctx->psmap)
147 		unmap_mapping_range(ctx->psmap, 0, SPUFS_PS_MAP_SIZE, 1);
148 	mutex_unlock(&ctx->mapping_lock);
149 }
150 
151 /**
152  * spu_acquire_saved - lock spu contex and make sure it is in saved state
153  * @ctx:	spu contex to lock
154  */
155 int spu_acquire_saved(struct spu_context *ctx)
156 {
157 	int ret;
158 
159 	spu_context_nospu_trace(spu_acquire_saved__enter, ctx);
160 
161 	ret = spu_acquire(ctx);
162 	if (ret)
163 		return ret;
164 
165 	if (ctx->state != SPU_STATE_SAVED) {
166 		set_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags);
167 		spu_deactivate(ctx);
168 	}
169 
170 	return 0;
171 }
172 
173 /**
174  * spu_release_saved - unlock spu context and return it to the runqueue
175  * @ctx:	context to unlock
176  */
177 void spu_release_saved(struct spu_context *ctx)
178 {
179 	BUG_ON(ctx->state != SPU_STATE_SAVED);
180 
181 	if (test_and_clear_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags) &&
182 			test_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags))
183 		spu_activate(ctx, 0);
184 
185 	spu_release(ctx);
186 }
187 
188