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/slab.h>
  24 #include <asm/spu.h>
  25 #include <asm/spu_csa.h>
  26 #include "spufs.h"
  27
  28 struct spu_context *alloc_spu_context(void)
  29 {
  30         struct spu_context *ctx;
  31         ctx = kmalloc(sizeof *ctx, GFP_KERNEL);
  32         if (!ctx)
  33                 goto out;
  34         /* Future enhancement: do not call spu_alloc()
  35          * here.  This step should be deferred until
  36          * spu_run()!!
  37          *
  38          * More work needs to be done to read(),
  39          * write(), mmap(), etc., so that operations
  40          * are performed on CSA when the context is
  41          * not currently being run.  In this way we
  42          * can support arbitrarily large number of
  43          * entries in /spu, allow state queries, etc.
  44          */
  45         ctx->spu = spu_alloc();
  46         if (!ctx->spu)
  47                 goto out_free;
  48         spu_init_csa(&ctx->csa);
  49         if (!ctx->csa.lscsa) {
  50                 spu_free(ctx->spu);
  51                 goto out_free;
  52         }
  53         init_rwsem(&ctx->backing_sema);
  54         spin_lock_init(&ctx->mmio_lock);
  55         kref_init(&ctx->kref);
  56         goto out;
  57 out_free:
  58         kfree(ctx);
  59         ctx = NULL;
  60 out:
  61         return ctx;
  62 }
  63
  64 void destroy_spu_context(struct kref *kref)
  65 {
  66         struct spu_context *ctx;
  67         ctx = container_of(kref, struct spu_context, kref);
  68         if (ctx->spu)
  69                 spu_free(ctx->spu);
  70         spu_fini_csa(&ctx->csa);
  71         kfree(ctx);
  72 }
  73
  74 struct spu_context * get_spu_context(struct spu_context *ctx)
  75 {
  76         kref_get(&ctx->kref);
  77         return ctx;
  78 }
  79
  80 int put_spu_context(struct spu_context *ctx)
  81 {
  82         return kref_put(&ctx->kref, &destroy_spu_context);
  83 }
  84
  85