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 <linux/sched/mm.h>
29 
30 #include <asm/spu.h>
31 #include <asm/spu_csa.h>
32 #include "spufs.h"
33 #include "sputrace.h"
34 
35 
36 atomic_t nr_spu_contexts = ATOMIC_INIT(0);
37 
38 struct spu_context *alloc_spu_context(struct spu_gang *gang)
39 {
40 	struct spu_context *ctx;
41 
42 	ctx = kzalloc(sizeof *ctx, GFP_KERNEL);
43 	if (!ctx)
44 		goto out;
45 	/* Binding to physical processor deferred
46 	 * until spu_activate().
47 	 */
48 	if (spu_init_csa(&ctx->csa))
49 		goto out_free;
50 	spin_lock_init(&ctx->mmio_lock);
51 	mutex_init(&ctx->mapping_lock);
52 	kref_init(&ctx->kref);
53 	mutex_init(&ctx->state_mutex);
54 	mutex_init(&ctx->run_mutex);
55 	init_waitqueue_head(&ctx->ibox_wq);
56 	init_waitqueue_head(&ctx->wbox_wq);
57 	init_waitqueue_head(&ctx->stop_wq);
58 	init_waitqueue_head(&ctx->mfc_wq);
59 	init_waitqueue_head(&ctx->run_wq);
60 	ctx->state = SPU_STATE_SAVED;
61 	ctx->ops = &spu_backing_ops;
62 	ctx->owner = get_task_mm(current);
63 	INIT_LIST_HEAD(&ctx->rq);
64 	INIT_LIST_HEAD(&ctx->aff_list);
65 	if (gang)
66 		spu_gang_add_ctx(gang, ctx);
67 
68 	__spu_update_sched_info(ctx);
69 	spu_set_timeslice(ctx);
70 	ctx->stats.util_state = SPU_UTIL_IDLE_LOADED;
71 	ctx->stats.tstamp = ktime_get_ns();
72 
73 	atomic_inc(&nr_spu_contexts);
74 	goto out;
75 out_free:
76 	kfree(ctx);
77 	ctx = NULL;
78 out:
79 	return ctx;
80 }
81 
82 void 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 
101 struct spu_context * get_spu_context(struct spu_context *ctx)
102 {
103 	kref_get(&ctx->kref);
104 	return ctx;
105 }
106 
107 int 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 */
113 void 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 
132 void 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  */
156 int 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  */
178 void 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 
189