LXR linux/arch/powerpc/platforms/cell/spufs/context.c

   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