1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * SPU file system -- SPU context management
4  *
5  * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
6  *
7  * Author: Arnd Bergmann <arndb@de.ibm.com>
8  */
9 
10 #include <linux/fs.h>
11 #include <linux/mm.h>
12 #include <linux/slab.h>
13 #include <linux/atomic.h>
14 #include <linux/sched.h>
15 #include <linux/sched/mm.h>
16 
17 #include <asm/spu.h>
18 #include <asm/spu_csa.h>
19 #include "spufs.h"
20 #include "sputrace.h"
21 
22 
23 atomic_t nr_spu_contexts = ATOMIC_INIT(0);
24 
alloc_spu_context(struct spu_gang * gang)25 struct spu_context *alloc_spu_context(struct spu_gang *gang)
26 {
27 	struct spu_context *ctx;
28 
29 	ctx = kzalloc(sizeof *ctx, GFP_KERNEL);
30 	if (!ctx)
31 		goto out;
32 	/* Binding to physical processor deferred
33 	 * until spu_activate().
34 	 */
35 	if (spu_init_csa(&ctx->csa))
36 		goto out_free;
37 	spin_lock_init(&ctx->mmio_lock);
38 	mutex_init(&ctx->mapping_lock);
39 	kref_init(&ctx->kref);
40 	mutex_init(&ctx->state_mutex);
41 	mutex_init(&ctx->run_mutex);
42 	init_waitqueue_head(&ctx->ibox_wq);
43 	init_waitqueue_head(&ctx->wbox_wq);
44 	init_waitqueue_head(&ctx->stop_wq);
45 	init_waitqueue_head(&ctx->mfc_wq);
46 	init_waitqueue_head(&ctx->run_wq);
47 	ctx->state = SPU_STATE_SAVED;
48 	ctx->ops = &spu_backing_ops;
49 	ctx->owner = get_task_mm(current);
50 	INIT_LIST_HEAD(&ctx->rq);
51 	INIT_LIST_HEAD(&ctx->aff_list);
52 	if (gang)
53 		spu_gang_add_ctx(gang, ctx);
54 
55 	__spu_update_sched_info(ctx);
56 	spu_set_timeslice(ctx);
57 	ctx->stats.util_state = SPU_UTIL_IDLE_LOADED;
58 	ctx->stats.tstamp = ktime_get_ns();
59 
60 	atomic_inc(&nr_spu_contexts);
61 	goto out;
62 out_free:
63 	kfree(ctx);
64 	ctx = NULL;
65 out:
66 	return ctx;
67 }
68 
destroy_spu_context(struct kref * kref)69 void destroy_spu_context(struct kref *kref)
70 {
71 	struct spu_context *ctx;
72 	ctx = container_of(kref, struct spu_context, kref);
73 	spu_context_nospu_trace(destroy_spu_context__enter, ctx);
74 	mutex_lock(&ctx->state_mutex);
75 	spu_deactivate(ctx);
76 	mutex_unlock(&ctx->state_mutex);
77 	spu_fini_csa(&ctx->csa);
78 	if (ctx->gang)
79 		spu_gang_remove_ctx(ctx->gang, ctx);
80 	if (ctx->prof_priv_kref)
81 		kref_put(ctx->prof_priv_kref, ctx->prof_priv_release);
82 	BUG_ON(!list_empty(&ctx->rq));
83 	atomic_dec(&nr_spu_contexts);
84 	kfree(ctx->switch_log);
85 	kfree(ctx);
86 }
87 
get_spu_context(struct spu_context * ctx)88 struct spu_context * get_spu_context(struct spu_context *ctx)
89 {
90 	kref_get(&ctx->kref);
91 	return ctx;
92 }
93 
put_spu_context(struct spu_context * ctx)94 int put_spu_context(struct spu_context *ctx)
95 {
96 	return kref_put(&ctx->kref, &destroy_spu_context);
97 }
98 
99 /* give up the mm reference when the context is about to be destroyed */
spu_forget(struct spu_context * ctx)100 void spu_forget(struct spu_context *ctx)
101 {
102 	struct mm_struct *mm;
103 
104 	/*
105 	 * This is basically an open-coded spu_acquire_saved, except that
106 	 * we don't acquire the state mutex interruptible, and we don't
107 	 * want this context to be rescheduled on release.
108 	 */
109 	mutex_lock(&ctx->state_mutex);
110 	if (ctx->state != SPU_STATE_SAVED)
111 		spu_deactivate(ctx);
112 
113 	mm = ctx->owner;
114 	ctx->owner = NULL;
115 	mmput(mm);
116 	spu_release(ctx);
117 }
118 
spu_unmap_mappings(struct spu_context * ctx)119 void spu_unmap_mappings(struct spu_context *ctx)
120 {
121 	mutex_lock(&ctx->mapping_lock);
122 	if (ctx->local_store)
123 		unmap_mapping_range(ctx->local_store, 0, LS_SIZE, 1);
124 	if (ctx->mfc)
125 		unmap_mapping_range(ctx->mfc, 0, SPUFS_MFC_MAP_SIZE, 1);
126 	if (ctx->cntl)
127 		unmap_mapping_range(ctx->cntl, 0, SPUFS_CNTL_MAP_SIZE, 1);
128 	if (ctx->signal1)
129 		unmap_mapping_range(ctx->signal1, 0, SPUFS_SIGNAL_MAP_SIZE, 1);
130 	if (ctx->signal2)
131 		unmap_mapping_range(ctx->signal2, 0, SPUFS_SIGNAL_MAP_SIZE, 1);
132 	if (ctx->mss)
133 		unmap_mapping_range(ctx->mss, 0, SPUFS_MSS_MAP_SIZE, 1);
134 	if (ctx->psmap)
135 		unmap_mapping_range(ctx->psmap, 0, SPUFS_PS_MAP_SIZE, 1);
136 	mutex_unlock(&ctx->mapping_lock);
137 }
138 
139 /**
140  * spu_acquire_saved - lock spu contex and make sure it is in saved state
141  * @ctx:	spu contex to lock
142  */
spu_acquire_saved(struct spu_context * ctx)143 int spu_acquire_saved(struct spu_context *ctx)
144 {
145 	int ret;
146 
147 	spu_context_nospu_trace(spu_acquire_saved__enter, ctx);
148 
149 	ret = spu_acquire(ctx);
150 	if (ret)
151 		return ret;
152 
153 	if (ctx->state != SPU_STATE_SAVED) {
154 		set_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags);
155 		spu_deactivate(ctx);
156 	}
157 
158 	return 0;
159 }
160 
161 /**
162  * spu_release_saved - unlock spu context and return it to the runqueue
163  * @ctx:	context to unlock
164  */
spu_release_saved(struct spu_context * ctx)165 void spu_release_saved(struct spu_context *ctx)
166 {
167 	BUG_ON(ctx->state != SPU_STATE_SAVED);
168 
169 	if (test_and_clear_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags) &&
170 			test_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags))
171 		spu_activate(ctx, 0);
172 
173 	spu_release(ctx);
174 }
175 
176