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/slab.h>
  26 #include <linux/atomic.h>
  27 #include <linux/sched.h>
  28 #include <asm/spu.h>
  29 #include <asm/spu_csa.h>
  30 #include "spufs.h"
  31 #include "sputrace.h"
  32
  33
  34 atomic_t nr_spu_contexts = ATOMIC_INIT(0);
  35
  36 struct spu_context *alloc_spu_context(struct spu_gang *gang)
  37 {
  38         struct spu_context *ctx;
  39         struct timespec ts;
  40
  41         ctx = kzalloc(sizeof *ctx, GFP_KERNEL);
  42         if (!ctx)
  43                 goto out;
  44         /* Binding to physical processor deferred
  45          * until spu_activate().
  46          */
  47         if (spu_init_csa(&ctx->csa))
  48                 goto out_free;
  49         spin_lock_init(&ctx->mmio_lock);
  50         mutex_init(&ctx->mapping_lock);
  51         kref_init(&ctx->kref);
  52         mutex_init(&ctx->state_mutex);
  53         mutex_init(&ctx->run_mutex);
  54         init_waitqueue_head(&ctx->ibox_wq);
  55         init_waitqueue_head(&ctx->wbox_wq);
  56         init_waitqueue_head(&ctx->stop_wq);
  57         init_waitqueue_head(&ctx->mfc_wq);
  58         init_waitqueue_head(&ctx->run_wq);
  59         ctx->state = SPU_STATE_SAVED;
  60         ctx->ops = &spu_backing_ops;
  61         ctx->owner = get_task_mm(current);
  62         INIT_LIST_HEAD(&ctx->rq);
  63         INIT_LIST_HEAD(&ctx->aff_list);
  64         if (gang)
  65                 spu_gang_add_ctx(gang, ctx);
  66
  67         __spu_update_sched_info(ctx);
  68         spu_set_timeslice(ctx);
  69         ctx->stats.util_state = SPU_UTIL_IDLE_LOADED;
  70         ktime_get_ts(&ts);
  71         ctx->stats.tstamp = timespec_to_ns(&ts);
  72
  73         atomic_inc(&nr_spu_contexts);
  74         goto out;
  75 out_free:
  76         kfree(ctx);
  77         ctx = NULL;
  78 out:
  79         return ctx;
  80 }
  81
  82 void destroy_spu_context(struct kref *kref)
  83 {
  84         struct spu_context *ctx;
  85         ctx = container_of(kref, struct spu_context, kref);
  86         spu_context_nospu_trace(destroy_spu_context__enter, ctx);
  87         mutex_lock(&ctx->state_mutex);
  88         spu_deactivate(ctx);
  89         mutex_unlock(&ctx->state_mutex);
  90         spu_fini_csa(&ctx->csa);
  91         if (ctx->gang)
  92                 spu_gang_remove_ctx(ctx->gang, ctx);
  93         if (ctx->prof_priv_kref)
  94                 kref_put(ctx->prof_priv_kref, ctx->prof_priv_release);
  95         BUG_ON(!list_empty(&ctx->rq));
  96         atomic_dec(&nr_spu_contexts);
  97         kfree(ctx->switch_log);
  98         kfree(ctx);
  99 }
 100
 101 struct spu_context * get_spu_context(struct spu_context *ctx)
 102 {
 103         kref_get(&ctx->kref);
 104         return ctx;
 105 }
 106
 107 int put_spu_context(struct spu_context *ctx)
 108 {
 109         return kref_put(&ctx->kref, &destroy_spu_context);
 110 }
 111
 112 /* give up the mm reference when the context is about to be destroyed */
 113 void spu_forget(struct spu_context *ctx)
 114 {
 115         struct mm_struct *mm;
 116
 117         /*
 118          * This is basically an open-coded spu_acquire_saved, except that
 119          * we don't acquire the state mutex interruptible, and we don't
 120          * want this context to be rescheduled on release.
 121          */
 122         mutex_lock(&ctx->state_mutex);
 123         if (ctx->state != SPU_STATE_SAVED)
 124                 spu_deactivate(ctx);
 125
 126         mm = ctx->owner;
 127         ctx->owner = NULL;
 128         mmput(mm);
 129         spu_release(ctx);
 130 }
 131
 132 void spu_unmap_mappings(struct spu_context *ctx)
 133 {
 134         mutex_lock(&ctx->mapping_lock);
 135         if (ctx->local_store)
 136                 unmap_mapping_range(ctx->local_store, 0, LS_SIZE, 1);
 137         if (ctx->mfc)
 138                 unmap_mapping_range(ctx->mfc, 0, SPUFS_MFC_MAP_SIZE, 1);
 139         if (ctx->cntl)
 140                 unmap_mapping_range(ctx->cntl, 0, SPUFS_CNTL_MAP_SIZE, 1);
 141         if (ctx->signal1)
 142                 unmap_mapping_range(ctx->signal1, 0, SPUFS_SIGNAL_MAP_SIZE, 1);
 143         if (ctx->signal2)
 144                 unmap_mapping_range(ctx->signal2, 0, SPUFS_SIGNAL_MAP_SIZE, 1);
 145         if (ctx->mss)
 146                 unmap_mapping_range(ctx->mss, 0, SPUFS_MSS_MAP_SIZE, 1);
 147         if (ctx->psmap)
 148                 unmap_mapping_range(ctx->psmap, 0, SPUFS_PS_MAP_SIZE, 1);
 149         mutex_unlock(&ctx->mapping_lock);
 150 }
 151
 152 /**
 153  * spu_acquire_saved - lock spu contex and make sure it is in saved state
 154  * @ctx:        spu contex to lock
 155  */
 156 int spu_acquire_saved(struct spu_context *ctx)
 157 {
 158         int ret;
 159
 160         spu_context_nospu_trace(spu_acquire_saved__enter, ctx);
 161
 162         ret = spu_acquire(ctx);
 163         if (ret)
 164                 return ret;
 165
 166         if (ctx->state != SPU_STATE_SAVED) {
 167                 set_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags);
 168                 spu_deactivate(ctx);
 169         }
 170
 171         return 0;
 172 }
 173
 174 /**
 175  * spu_release_saved - unlock spu context and return it to the runqueue
 176  * @ctx:        context to unlock
 177  */
 178 void spu_release_saved(struct spu_context *ctx)
 179 {
 180         BUG_ON(ctx->state != SPU_STATE_SAVED);
 181
 182         if (test_and_clear_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags) &&
 183                         test_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags))
 184                 spu_activate(ctx, 0);
 185
 186         spu_release(ctx);
 187 }
 188