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 <asm/spu.h>
27 #include <asm/spu_csa.h>
28 #include "spufs.h"
29 
30 struct spu_context *alloc_spu_context(struct spu_gang *gang)
31 {
32 	struct spu_context *ctx;
33 	ctx = kzalloc(sizeof *ctx, GFP_KERNEL);
34 	if (!ctx)
35 		goto out;
36 	/* Binding to physical processor deferred
37 	 * until spu_activate().
38 	 */
39 	if (spu_init_csa(&ctx->csa))
40 		goto out_free;
41 	spin_lock_init(&ctx->mmio_lock);
42 	mutex_init(&ctx->mapping_lock);
43 	kref_init(&ctx->kref);
44 	mutex_init(&ctx->state_mutex);
45 	mutex_init(&ctx->run_mutex);
46 	init_waitqueue_head(&ctx->ibox_wq);
47 	init_waitqueue_head(&ctx->wbox_wq);
48 	init_waitqueue_head(&ctx->stop_wq);
49 	init_waitqueue_head(&ctx->mfc_wq);
50 	ctx->state = SPU_STATE_SAVED;
51 	ctx->ops = &spu_backing_ops;
52 	ctx->owner = get_task_mm(current);
53 	INIT_LIST_HEAD(&ctx->rq);
54 	if (gang)
55 		spu_gang_add_ctx(gang, ctx);
56 	ctx->rt_priority = current->rt_priority;
57 	ctx->policy = current->policy;
58 	ctx->prio = current->prio;
59 	INIT_DELAYED_WORK(&ctx->sched_work, spu_sched_tick);
60 	goto out;
61 out_free:
62 	kfree(ctx);
63 	ctx = NULL;
64 out:
65 	return ctx;
66 }
67 
68 void destroy_spu_context(struct kref *kref)
69 {
70 	struct spu_context *ctx;
71 	ctx = container_of(kref, struct spu_context, kref);
72 	mutex_lock(&ctx->state_mutex);
73 	spu_deactivate(ctx);
74 	mutex_unlock(&ctx->state_mutex);
75 	spu_fini_csa(&ctx->csa);
76 	if (ctx->gang)
77 		spu_gang_remove_ctx(ctx->gang, ctx);
78 	BUG_ON(!list_empty(&ctx->rq));
79 	kfree(ctx);
80 }
81 
82 struct spu_context * get_spu_context(struct spu_context *ctx)
83 {
84 	kref_get(&ctx->kref);
85 	return ctx;
86 }
87 
88 int put_spu_context(struct spu_context *ctx)
89 {
90 	return kref_put(&ctx->kref, &destroy_spu_context);
91 }
92 
93 /* give up the mm reference when the context is about to be destroyed */
94 void spu_forget(struct spu_context *ctx)
95 {
96 	struct mm_struct *mm;
97 	spu_acquire_saved(ctx);
98 	mm = ctx->owner;
99 	ctx->owner = NULL;
100 	mmput(mm);
101 	spu_release(ctx);
102 }
103 
104 void spu_unmap_mappings(struct spu_context *ctx)
105 {
106 	mutex_lock(&ctx->mapping_lock);
107 	if (ctx->local_store)
108 		unmap_mapping_range(ctx->local_store, 0, LS_SIZE, 1);
109 	if (ctx->mfc)
110 		unmap_mapping_range(ctx->mfc, 0, 0x1000, 1);
111 	if (ctx->cntl)
112 		unmap_mapping_range(ctx->cntl, 0, 0x1000, 1);
113 	if (ctx->signal1)
114 		unmap_mapping_range(ctx->signal1, 0, PAGE_SIZE, 1);
115 	if (ctx->signal2)
116 		unmap_mapping_range(ctx->signal2, 0, PAGE_SIZE, 1);
117 	if (ctx->mss)
118 		unmap_mapping_range(ctx->mss, 0, 0x1000, 1);
119 	if (ctx->psmap)
120 		unmap_mapping_range(ctx->psmap, 0, 0x20000, 1);
121 	mutex_unlock(&ctx->mapping_lock);
122 }
123 
124 /**
125  * spu_acquire_runnable - lock spu contex and make sure it is in runnable state
126  * @ctx:	spu contex to lock
127  *
128  * Note:
129  *	Returns 0 and with the context locked on success
130  *	Returns negative error and with the context _unlocked_ on failure.
131  */
132 int spu_acquire_runnable(struct spu_context *ctx, unsigned long flags)
133 {
134 	int ret = -EINVAL;
135 
136 	spu_acquire(ctx);
137 	if (ctx->state == SPU_STATE_SAVED) {
138 		/*
139 		 * Context is about to be freed, so we can't acquire it anymore.
140 		 */
141 		if (!ctx->owner)
142 			goto out_unlock;
143 		ret = spu_activate(ctx, flags);
144 		if (ret)
145 			goto out_unlock;
146 	}
147 
148 	return 0;
149 
150  out_unlock:
151 	spu_release(ctx);
152 	return ret;
153 }
154 
155 /**
156  * spu_acquire_saved - lock spu contex and make sure it is in saved state
157  * @ctx:	spu contex to lock
158  */
159 void spu_acquire_saved(struct spu_context *ctx)
160 {
161 	spu_acquire(ctx);
162 	if (ctx->state != SPU_STATE_SAVED)
163 		spu_deactivate(ctx);
164 }
165