5473af049d
Add some infrastructure for saving and restoring the context of an SPE. This patch creates a new structure that can hold the whole state of a physical SPE in memory. It also contains code that avoids races during the context switch and the binary code that is loaded to the SPU in order to access its registers. The actual PPE- and SPE-side context switch code are two separate patches. Signed-off-by: Arnd Bergmann <arndb@de.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
86 lines
2.1 KiB
C
86 lines
2.1 KiB
C
/*
|
|
* SPU file system -- SPU context management
|
|
*
|
|
* (C) Copyright IBM Deutschland Entwicklung GmbH 2005
|
|
*
|
|
* Author: Arnd Bergmann <arndb@de.ibm.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2, or (at your option)
|
|
* any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
|
*/
|
|
|
|
#include <linux/slab.h>
|
|
#include <asm/spu.h>
|
|
#include <asm/spu_csa.h>
|
|
#include "spufs.h"
|
|
|
|
struct spu_context *alloc_spu_context(void)
|
|
{
|
|
struct spu_context *ctx;
|
|
ctx = kmalloc(sizeof *ctx, GFP_KERNEL);
|
|
if (!ctx)
|
|
goto out;
|
|
/* Future enhancement: do not call spu_alloc()
|
|
* here. This step should be deferred until
|
|
* spu_run()!!
|
|
*
|
|
* More work needs to be done to read(),
|
|
* write(), mmap(), etc., so that operations
|
|
* are performed on CSA when the context is
|
|
* not currently being run. In this way we
|
|
* can support arbitrarily large number of
|
|
* entries in /spu, allow state queries, etc.
|
|
*/
|
|
ctx->spu = spu_alloc();
|
|
if (!ctx->spu)
|
|
goto out_free;
|
|
spu_init_csa(&ctx->csa);
|
|
if (!ctx->csa.lscsa) {
|
|
spu_free(ctx->spu);
|
|
goto out_free;
|
|
}
|
|
init_rwsem(&ctx->backing_sema);
|
|
spin_lock_init(&ctx->mmio_lock);
|
|
kref_init(&ctx->kref);
|
|
goto out;
|
|
out_free:
|
|
kfree(ctx);
|
|
ctx = NULL;
|
|
out:
|
|
return ctx;
|
|
}
|
|
|
|
void destroy_spu_context(struct kref *kref)
|
|
{
|
|
struct spu_context *ctx;
|
|
ctx = container_of(kref, struct spu_context, kref);
|
|
if (ctx->spu)
|
|
spu_free(ctx->spu);
|
|
spu_fini_csa(&ctx->csa);
|
|
kfree(ctx);
|
|
}
|
|
|
|
struct spu_context * get_spu_context(struct spu_context *ctx)
|
|
{
|
|
kref_get(&ctx->kref);
|
|
return ctx;
|
|
}
|
|
|
|
int put_spu_context(struct spu_context *ctx)
|
|
{
|
|
return kref_put(&ctx->kref, &destroy_spu_context);
|
|
}
|
|
|
|
|