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 <asm/atomic.h>
  27 #include <asm/spu.h>
  28 #include <asm/spu_csa.h>
  29 #include "spufs.h"
  30
  31
  32 atomic_t nr_spu_contexts = ATOMIC_INIT(0);
  33
  34 struct spu_context *alloc_spu_context(struct spu_gang *gang)
  35 {
  36         struct spu_context *ctx;
  37         ctx = kzalloc(sizeof *ctx, GFP_KERNEL);
  38         if (!ctx)
  39                 goto out;
  40         /* Binding to physical processor deferred
  41          * until spu_activate().
  42          */
  43         if (spu_init_csa(&ctx->csa))
  44                 goto out_free;
  45         spin_lock_init(&ctx->mmio_lock);
  46         mutex_init(&ctx->mapping_lock);
  47         kref_init(&ctx->kref);
  48         mutex_init(&ctx->state_mutex);
  49         mutex_init(&ctx->run_mutex);
  50         init_waitqueue_head(&ctx->ibox_wq);
  51         init_waitqueue_head(&ctx->wbox_wq);
  52         init_waitqueue_head(&ctx->stop_wq);
  53         init_waitqueue_head(&ctx->mfc_wq);
  54         ctx->state = SPU_STATE_SAVED;
  55         ctx->ops = &spu_backing_ops;
  56         ctx->owner = get_task_mm(current);
  57         INIT_LIST_HEAD(&ctx->rq);
  58         INIT_LIST_HEAD(&ctx->aff_list);
  59         if (gang)
  60                 spu_gang_add_ctx(gang, ctx);
  61         ctx->cpus_allowed = current->cpus_allowed;
  62         spu_set_timeslice(ctx);
  63         ctx->stats.util_state = SPU_UTIL_IDLE_LOADED;
  64
  65         atomic_inc(&nr_spu_contexts);
  66         goto out;
  67 out_free:
  68         kfree(ctx);
  69         ctx = NULL;
  70 out:
  71         return ctx;
  72 }
  73
  74 void destroy_spu_context(struct kref *kref)
  75 {
  76         struct spu_context *ctx;
  77         ctx = container_of(kref, struct spu_context, kref);
  78         mutex_lock(&ctx->state_mutex);
  79         spu_deactivate(ctx);
  80         mutex_unlock(&ctx->state_mutex);
  81         spu_fini_csa(&ctx->csa);
  82         if (ctx->gang)
  83                 spu_gang_remove_ctx(ctx->gang, ctx);
  84         BUG_ON(!list_empty(&ctx->rq));
  85         atomic_dec(&nr_spu_contexts);
  86         kfree(ctx);
  87 }
  88
  89 struct spu_context * get_spu_context(struct spu_context *ctx)
  90 {
  91         kref_get(&ctx->kref);
  92         return ctx;
  93 }
  94
  95 int put_spu_context(struct spu_context *ctx)
  96 {
  97         return kref_put(&ctx->kref, &destroy_spu_context);
  98 }
  99
 100 /* give up the mm reference when the context is about to be destroyed */
 101 void spu_forget(struct spu_context *ctx)
 102 {
 103         struct mm_struct *mm;
 104         spu_acquire_saved(ctx);
 105         mm = ctx->owner;
 106         ctx->owner = NULL;
 107         mmput(mm);
 108         spu_release(ctx);
 109 }
 110
 111 void spu_unmap_mappings(struct spu_context *ctx)
 112 {
 113         mutex_lock(&ctx->mapping_lock);
 114         if (ctx->local_store)
 115                 unmap_mapping_range(ctx->local_store, 0, LS_SIZE, 1);
 116         if (ctx->mfc)
 117                 unmap_mapping_range(ctx->mfc, 0, 0x1000, 1);
 118         if (ctx->cntl)
 119                 unmap_mapping_range(ctx->cntl, 0, 0x1000, 1);
 120         if (ctx->signal1)
 121                 unmap_mapping_range(ctx->signal1, 0, PAGE_SIZE, 1);
 122         if (ctx->signal2)
 123                 unmap_mapping_range(ctx->signal2, 0, PAGE_SIZE, 1);
 124         if (ctx->mss)
 125                 unmap_mapping_range(ctx->mss, 0, 0x1000, 1);
 126         if (ctx->psmap)
 127                 unmap_mapping_range(ctx->psmap, 0, 0x20000, 1);
 128         mutex_unlock(&ctx->mapping_lock);
 129 }
 130
 131 /**
 132  * spu_acquire_runnable - lock spu contex and make sure it is in runnable state
 133  * @ctx:        spu contex to lock
 134  *
 135  * Note:
 136  *      Returns 0 and with the context locked on success
 137  *      Returns negative error and with the context _unlocked_ on failure.
 138  */
 139 int spu_acquire_runnable(struct spu_context *ctx, unsigned long flags)
 140 {
 141         int ret = -EINVAL;
 142
 143         spu_acquire(ctx);
 144         if (ctx->state == SPU_STATE_SAVED) {
 145                 /*
 146                  * Context is about to be freed, so we can't acquire it anymore.
 147                  */
 148                 if (!ctx->owner)
 149                         goto out_unlock;
 150                 ret = spu_activate(ctx, flags);
 151                 if (ret)
 152                         goto out_unlock;
 153         }
 154
 155         return 0;
 156
 157  out_unlock:
 158         spu_release(ctx);
 159         return ret;
 160 }
 161
 162 /**
 163  * spu_acquire_saved - lock spu contex and make sure it is in saved state
 164  * @ctx:        spu contex to lock
 165  */
 166 void spu_acquire_saved(struct spu_context *ctx)
 167 {
 168         spu_acquire(ctx);
 169         if (ctx->state != SPU_STATE_SAVED) {
 170                 set_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags);
 171                 spu_deactivate(ctx);
 172         }
 173 }
 174
 175 /**
 176  * spu_release_saved - unlock spu context and return it to the runqueue
 177  * @ctx:        context to unlock
 178  */
 179 void spu_release_saved(struct spu_context *ctx)
 180 {
 181         BUG_ON(ctx->state != SPU_STATE_SAVED);
 182
 183         if (test_and_clear_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags))
 184                 spu_activate(ctx, 0);
 185
 186         spu_release(ctx);
 187 }