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(csa: &ctx->csa))
36 goto out_free;
37 spin_lock_init(&ctx->mmio_lock);
38 mutex_init(&ctx->mapping_lock);
39 kref_init(kref: &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(list: &ctx->rq);
51 INIT_LIST_HEAD(list: &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(v: &nr_spu_contexts);
61 goto out;
62out_free:
63 kfree(objp: 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(lock: &ctx->state_mutex);
77 spu_fini_csa(csa: &ctx->csa);
78 if (ctx->gang)
79 spu_gang_remove_ctx(gang: ctx->gang, ctx);
80 if (ctx->prof_priv_kref)
81 kref_put(kref: ctx->prof_priv_kref, release: ctx->prof_priv_release);
82 BUG_ON(!list_empty(&ctx->rq));
83 atomic_dec(v: &nr_spu_contexts);
84 kfree(objp: ctx->switch_log);
85 kfree(objp: ctx);
86}
87
88struct spu_context * get_spu_context(struct spu_context *ctx)
89{
90 kref_get(kref: &ctx->kref);
91 return ctx;
92}
93
94int put_spu_context(struct spu_context *ctx)
95{
96 return kref_put(kref: &ctx->kref, release: &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(mapping: ctx->local_store, holebegin: 0, holelen: LS_SIZE, even_cows: 1);
124 if (ctx->mfc)
125 unmap_mapping_range(mapping: ctx->mfc, holebegin: 0, SPUFS_MFC_MAP_SIZE, even_cows: 1);
126 if (ctx->cntl)
127 unmap_mapping_range(mapping: ctx->cntl, holebegin: 0, SPUFS_CNTL_MAP_SIZE, even_cows: 1);
128 if (ctx->signal1)
129 unmap_mapping_range(mapping: ctx->signal1, holebegin: 0, SPUFS_SIGNAL_MAP_SIZE, even_cows: 1);
130 if (ctx->signal2)
131 unmap_mapping_range(mapping: ctx->signal2, holebegin: 0, SPUFS_SIGNAL_MAP_SIZE, even_cows: 1);
132 if (ctx->mss)
133 unmap_mapping_range(mapping: ctx->mss, holebegin: 0, SPUFS_MSS_MAP_SIZE, even_cows: 1);
134 if (ctx->psmap)
135 unmap_mapping_range(mapping: ctx->psmap, holebegin: 0, SPUFS_PS_MAP_SIZE, even_cows: 1);
136 mutex_unlock(lock: &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(nr: SPU_SCHED_WAS_ACTIVE, addr: &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(nr: SPU_SCHED_WAS_ACTIVE, addr: &ctx->sched_flags) &&
170 test_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags))
171 spu_activate(ctx, flags: 0);
172
173 spu_release(ctx);
174}
175
176

source code of linux/arch/powerpc/platforms/cell/spufs/context.c