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

   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/module.h>
  26 #include <linux/slab.h>
  27 #include <asm/atomic.h>
  28 #include <asm/spu.h>
  29 #include <asm/spu_csa.h>
  30 #include "spufs.h"
  31
  32
  33 atomic_t nr_spu_contexts = ATOMIC_INIT(0);
  34
  35 struct spu_context *alloc_spu_context(struct spu_gang *gang)
  36 {
  37         struct spu_context *ctx;
  38         struct timespec ts;
  39
  40         ctx = kzalloc(sizeof *ctx, GFP_KERNEL);
  41         if (!ctx)
  42                 goto out;
  43         /* Binding to physical processor deferred
  44          * until spu_activate().
  45          */
  46         if (spu_init_csa(&ctx->csa))
  47                 goto out_free;
  48         spin_lock_init(&ctx->mmio_lock);
  49         mutex_init(&ctx->mapping_lock);
  50         kref_init(&ctx->kref);
  51         mutex_init(&ctx->state_mutex);
  52         mutex_init(&ctx->run_mutex);
  53         init_waitqueue_head(&ctx->ibox_wq);
  54         init_waitqueue_head(&ctx->wbox_wq);
  55         init_waitqueue_head(&ctx->stop_wq);
  56         init_waitqueue_head(&ctx->mfc_wq);
  57         init_waitqueue_head(&ctx->run_wq);
  58         ctx->state = SPU_STATE_SAVED;
  59         ctx->ops = &spu_backing_ops;
  60         ctx->owner = get_task_mm(current);
  61         INIT_LIST_HEAD(&ctx->rq);
  62         INIT_LIST_HEAD(&ctx->aff_list);
  63         if (gang)
  64                 spu_gang_add_ctx(gang, ctx);
  65
  66         __spu_update_sched_info(ctx);
  67         spu_set_timeslice(ctx);
  68         ctx->stats.util_state = SPU_UTIL_IDLE_LOADED;
  69         ktime_get_ts(&ts);
  70         ctx->stats.tstamp = timespec_to_ns(&ts);
  71
  72         atomic_inc(&nr_spu_contexts);
  73         goto out;
  74 out_free:
  75         kfree(ctx);
  76         ctx = NULL;
  77 out:
  78         return ctx;
  79 }
  80
  81 void destroy_spu_context(struct kref *kref)
  82 {
  83         struct spu_context *ctx;
  84         ctx = container_of(kref, struct spu_context, kref);
  85         spu_context_nospu_trace(destroy_spu_context__enter, ctx);
  86         mutex_lock(&ctx->state_mutex);
  87         spu_deactivate(ctx);
  88         mutex_unlock(&ctx->state_mutex);
  89         spu_fini_csa(&ctx->csa);
  90         if (ctx->gang)
  91                 spu_gang_remove_ctx(ctx->gang, ctx);
  92         if (ctx->prof_priv_kref)
  93                 kref_put(ctx->prof_priv_kref, ctx->prof_priv_release);
  94         BUG_ON(!list_empty(&ctx->rq));
  95         atomic_dec(&nr_spu_contexts);
  96         kfree(ctx->switch_log);
  97         kfree(ctx);
  98 }
  99
 100 struct spu_context * get_spu_context(struct spu_context *ctx)
 101 {
 102         kref_get(&ctx->kref);
 103         return ctx;
 104 }
 105
 106 int put_spu_context(struct spu_context *ctx)
 107 {
 108         return kref_put(&ctx->kref, &destroy_spu_context);
 109 }
 110
 111 /* give up the mm reference when the context is about to be destroyed */
 112 void spu_forget(struct spu_context *ctx)
 113 {
 114         struct mm_struct *mm;
 115
 116         /*
 117          * This is basically an open-coded spu_acquire_saved, except that
 118          * we don't acquire the state mutex interruptible, and we don't
 119          * want this context to be rescheduled on release.
 120          */
 121         mutex_lock(&ctx->state_mutex);
 122         if (ctx->state != SPU_STATE_SAVED)
 123                 spu_deactivate(ctx);
 124
 125         mm = ctx->owner;
 126         ctx->owner = NULL;
 127         mmput(mm);
 128         spu_release(ctx);
 129 }
 130
 131 void spu_unmap_mappings(struct spu_context *ctx)
 132 {
 133         mutex_lock(&ctx->mapping_lock);
 134         if (ctx->local_store)
 135                 unmap_mapping_range(ctx->local_store, 0, LS_SIZE, 1);
 136         if (ctx->mfc)
 137                 unmap_mapping_range(ctx->mfc, 0, SPUFS_MFC_MAP_SIZE, 1);
 138         if (ctx->cntl)
 139                 unmap_mapping_range(ctx->cntl, 0, SPUFS_CNTL_MAP_SIZE, 1);
 140         if (ctx->signal1)
 141                 unmap_mapping_range(ctx->signal1, 0, SPUFS_SIGNAL_MAP_SIZE, 1);
 142         if (ctx->signal2)
 143                 unmap_mapping_range(ctx->signal2, 0, SPUFS_SIGNAL_MAP_SIZE, 1);
 144         if (ctx->mss)
 145                 unmap_mapping_range(ctx->mss, 0, SPUFS_MSS_MAP_SIZE, 1);
 146         if (ctx->psmap)
 147                 unmap_mapping_range(ctx->psmap, 0, SPUFS_PS_MAP_SIZE, 1);
 148         mutex_unlock(&ctx->mapping_lock);
 149 }
 150
 151 /**
 152  * spu_acquire_saved - lock spu contex and make sure it is in saved state
 153  * @ctx:        spu contex to lock
 154  */
 155 int spu_acquire_saved(struct spu_context *ctx)
 156 {
 157         int ret;
 158
 159         spu_context_nospu_trace(spu_acquire_saved__enter, ctx);
 160
 161         ret = spu_acquire(ctx);
 162         if (ret)
 163                 return ret;
 164
 165         if (ctx->state != SPU_STATE_SAVED) {
 166                 set_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags);
 167                 spu_deactivate(ctx);
 168         }
 169
 170         return 0;
 171 }
 172
 173 /**
 174  * spu_release_saved - unlock spu context and return it to the runqueue
 175  * @ctx:        context to unlock
 176  */
 177 void spu_release_saved(struct spu_context *ctx)
 178 {
 179         BUG_ON(ctx->state != SPU_STATE_SAVED);
 180
 181         if (test_and_clear_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags) &&
 182                         test_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags))
 183                 spu_activate(ctx, 0);
 184
 185         spu_release(ctx);
 186 }
 187