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
  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         ctx->stats.tstamp = ktime_get_ns();
  70
  71         atomic_inc(&nr_spu_contexts);
  72         goto out;
  73 out_free:
  74         kfree(ctx);
  75         ctx = NULL;
  76 out:
  77         return ctx;
  78 }
  79
  80 void destroy_spu_context(struct kref *kref)
  81 {
  82         struct spu_context *ctx;
  83         ctx = container_of(kref, struct spu_context, kref);
  84         spu_context_nospu_trace(destroy_spu_context__enter, ctx);
  85         mutex_lock(&ctx->state_mutex);
  86         spu_deactivate(ctx);
  87         mutex_unlock(&ctx->state_mutex);
  88         spu_fini_csa(&ctx->csa);
  89         if (ctx->gang)
  90                 spu_gang_remove_ctx(ctx->gang, ctx);
  91         if (ctx->prof_priv_kref)
  92                 kref_put(ctx->prof_priv_kref, ctx->prof_priv_release);
  93         BUG_ON(!list_empty(&ctx->rq));
  94         atomic_dec(&nr_spu_contexts);
  95         kfree(ctx->switch_log);
  96         kfree(ctx);
  97 }
  98
  99 struct spu_context * get_spu_context(struct spu_context *ctx)
 100 {
 101         kref_get(&ctx->kref);
 102         return ctx;
 103 }
 104
 105 int put_spu_context(struct spu_context *ctx)
 106 {
 107         return kref_put(&ctx->kref, &destroy_spu_context);
 108 }
 109
 110 /* give up the mm reference when the context is about to be destroyed */
 111 void spu_forget(struct spu_context *ctx)
 112 {
 113         struct mm_struct *mm;
 114
 115         /*
 116          * This is basically an open-coded spu_acquire_saved, except that
 117          * we don't acquire the state mutex interruptible, and we don't
 118          * want this context to be rescheduled on release.
 119          */
 120         mutex_lock(&ctx->state_mutex);
 121         if (ctx->state != SPU_STATE_SAVED)
 122                 spu_deactivate(ctx);
 123
 124         mm = ctx->owner;
 125         ctx->owner = NULL;
 126         mmput(mm);
 127         spu_release(ctx);
 128 }
 129
 130 void spu_unmap_mappings(struct spu_context *ctx)
 131 {
 132         mutex_lock(&ctx->mapping_lock);
 133         if (ctx->local_store)
 134                 unmap_mapping_range(ctx->local_store, 0, LS_SIZE, 1);
 135         if (ctx->mfc)
 136                 unmap_mapping_range(ctx->mfc, 0, SPUFS_MFC_MAP_SIZE, 1);
 137         if (ctx->cntl)
 138                 unmap_mapping_range(ctx->cntl, 0, SPUFS_CNTL_MAP_SIZE, 1);
 139         if (ctx->signal1)
 140                 unmap_mapping_range(ctx->signal1, 0, SPUFS_SIGNAL_MAP_SIZE, 1);
 141         if (ctx->signal2)
 142                 unmap_mapping_range(ctx->signal2, 0, SPUFS_SIGNAL_MAP_SIZE, 1);
 143         if (ctx->mss)
 144                 unmap_mapping_range(ctx->mss, 0, SPUFS_MSS_MAP_SIZE, 1);
 145         if (ctx->psmap)
 146                 unmap_mapping_range(ctx->psmap, 0, SPUFS_PS_MAP_SIZE, 1);
 147         mutex_unlock(&ctx->mapping_lock);
 148 }
 149
 150 /**
 151  * spu_acquire_saved - lock spu contex and make sure it is in saved state
 152  * @ctx:        spu contex to lock
 153  */
 154 int spu_acquire_saved(struct spu_context *ctx)
 155 {
 156         int ret;
 157
 158         spu_context_nospu_trace(spu_acquire_saved__enter, ctx);
 159
 160         ret = spu_acquire(ctx);
 161         if (ret)
 162                 return ret;
 163
 164         if (ctx->state != SPU_STATE_SAVED) {
 165                 set_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags);
 166                 spu_deactivate(ctx);
 167         }
 168
 169         return 0;
 170 }
 171
 172 /**
 173  * spu_release_saved - unlock spu context and return it to the runqueue
 174  * @ctx:        context to unlock
 175  */
 176 void spu_release_saved(struct spu_context *ctx)
 177 {
 178         BUG_ON(ctx->state != SPU_STATE_SAVED);
 179
 180         if (test_and_clear_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags) &&
 181                         test_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags))
 182                 spu_activate(ctx, 0);
 183
 184         spu_release(ctx);
 185 }
 186