path: root/arch/powerpc/platforms/cell/spufs/file.c

/*
 * SPU file system -- file contents
 *
 * (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/fs.h>
#include <linux/ioctl.h>
#include <linux/module.h>
#include <linux/pagemap.h>
#include <linux/poll.h>

#include <asm/io.h>
#include <asm/semaphore.h>
#include <asm/spu.h>
#include <asm/uaccess.h>

#include "spufs.h"


static int
spufs_mem_open(struct inode *inode, struct file *file)
{
	struct spufs_inode_info *i = SPUFS_I(inode);
	file->private_data = i->i_ctx;
	file->f_mapping = i->i_ctx->local_store;
	return 0;
}

static ssize_t
spufs_mem_read(struct file *file, char __user *buffer,
				size_t size, loff_t *pos)
{
	struct spu_context *ctx = file->private_data;
	char *local_store;
	int ret;

	spu_acquire(ctx);

	local_store = ctx->ops->get_ls(ctx);
	ret = simple_read_from_buffer(buffer, size, pos, local_store, LS_SIZE);

	spu_release(ctx);
	return ret;
}

static ssize_t
spufs_mem_write(struct file *file, const char __user *buffer,
					size_t size, loff_t *pos)
{
	struct spu_context *ctx = file->private_data;
	char *local_store;
	int ret;

	size = min_t(ssize_t, LS_SIZE - *pos, size);
	if (size <= 0)
		return -EFBIG;
	*pos += size;

	spu_acquire(ctx);

	local_store = ctx->ops->get_ls(ctx);
	ret = copy_from_user(local_store + *pos - size,
			     buffer, size) ? -EFAULT : size;

	spu_release(ctx);
	return ret;
}

#ifdef CONFIG_SPARSEMEM
static struct page *
spufs_mem_mmap_nopage(struct vm_area_struct *vma,
		      unsigned long address, int *type)
{
	struct page *page = NOPAGE_SIGBUS;

	struct spu_context *ctx = vma->vm_file->private_data;
	unsigned long offset = address - vma->vm_start;
	offset += vma->vm_pgoff << PAGE_SHIFT;

	spu_acquire(ctx);

	if (ctx->state == SPU_STATE_SAVED)
		page = vmalloc_to_page(ctx->csa.lscsa->ls + offset);
	else
		page = pfn_to_page((ctx->spu->local_store_phys + offset)
				   >> PAGE_SHIFT);

	spu_release(ctx);

	if (type)
		*type = VM_FAULT_MINOR;

	page_cache_get(page);
	return page;
}

static struct vm_operations_struct spufs_mem_mmap_vmops = {
	.nopage = spufs_mem_mmap_nopage,
};

static int
spufs_mem_mmap(struct file *file, struct vm_area_struct *vma)
{
	if (!(vma->vm_flags & VM_SHARED))
		return -EINVAL;

	/* FIXME: */
	vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
				     | _PAGE_NO_CACHE);

	vma->vm_ops = &spufs_mem_mmap_vmops;
	return 0;
}
#endif

static struct file_operations spufs_mem_fops = {
	.open	 = spufs_mem_open,
	.read    = spufs_mem_read,
	.write   = spufs_mem_write,
	.llseek  = generic_file_llseek,
#ifdef CONFIG_SPARSEMEM
	.mmap    = spufs_mem_mmap,
#endif
};

static int
spufs_regs_open(struct inode *inode, struct file *file)
{
	struct spufs_inode_info *i = SPUFS_I(inode);
	file->private_data = i->i_ctx;
	return 0;
}

static ssize_t
spufs_regs_read(struct file *file, char __user *buffer,
		size_t size, loff_t *pos)
{
	struct spu_context *ctx = file->private_data;
	struct spu_lscsa *lscsa = ctx->csa.lscsa;
	int ret;

	spu_acquire_saved(ctx);

	ret = simple_read_from_buffer(buffer, size, pos,
				      lscsa->gprs, sizeof lscsa->gprs);

	spu_release(ctx);
	return ret;
}

static ssize_t
spufs_regs_write(struct file *file, const char __user *buffer,
		 size_t size, loff_t *pos)
{
	struct spu_context *ctx = file->private_data;
	struct spu_lscsa *lscsa = ctx->csa.lscsa;
	int ret;

	size = min_t(ssize_t, sizeof lscsa->gprs - *pos, size);
	if (size <= 0)
		return -EFBIG;
	*pos += size;

	spu_acquire_saved