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
23atomic_t nr_spu_contexts = ATOMIC_INIT(0);
24
25struct 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;
62out_free:
63	kfree(ctx);
64	ctx = NULL;
65out:
66	return ctx;
67}
68
69void 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
88struct spu_context * get_spu_context(struct spu_context *ctx)
89{
90	kref_get(&ctx->kref);
91	return ctx;
92}
93
94int 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 */
100void 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
119void 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 */
143int 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 */
165void 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