file.c

linux内核源码

/*
 * SPU file system -- file contents
 *
 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
 *
 * Author: Arnd Bergmann <[e-mail]>
 *
 * 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.
 */

#undef DEBUG

#include <linux/fs.h>
#include <linux/ioctl.h>
#include <linux/module.h>
#include <linux/pagemap.h>
#include <linux/poll.h>
#include <linux/ptrace.h>
#include <linux/seq_file.h>

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

#include "spufs.h"

#define SPUFS_MMAP_4K (PAGE_SIZE == 0x1000)


static int
spufs_mem_open(struct inode *inode, struct file *file)
{
	struct spufs_inode_info *i = SPUFS_I(inode);
	struct spu_context *ctx = i->i_ctx;

	mutex_lock(&ctx->mapping_lock);
	file->private_data = ctx;
	if (!i->i_openers++)
		ctx->local_store = inode->i_mapping;
	mutex_unlock(&ctx->mapping_lock);
	return 0;
}

static int
spufs_mem_release(struct inode *inode, struct file *file)
{
	struct spufs_inode_info *i = SPUFS_I(inode);
	struct spu_context *ctx = i->i_ctx;

	mutex_lock(&ctx->mapping_lock);
	if (!--i->i_openers)
		ctx->local_store = NULL;
	mutex_unlock(&ctx->mapping_lock);
	return 0;
}

static ssize_t
__spufs_mem_read(struct spu_context *ctx, char __user *buffer,
			size_t size, loff_t *pos)
{
	char *local_store = ctx->ops->get_ls(ctx);
	return simple_read_from_buffer(buffer, size, pos, local_store,
					LS_SIZE);
}

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;
	ssize_t ret;

	spu_acquire(ctx);
	ret = __spufs_mem_read(ctx, buffer, size, pos);
	spu_release(ctx);
	return ret;
}

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

	if (pos < 0)
		return -EINVAL;
	if (pos > LS_SIZE)
		return -EFBIG;
	if (size > LS_SIZE - pos)
		size = LS_SIZE - pos;

	spu_acquire(ctx);
	local_store = ctx->ops->get_ls(ctx);
	ret = copy_from_user(local_store + pos, buffer, size);
	spu_release(ctx);

	if (ret)
		return -EFAULT;
	*ppos = pos + size;
	return size;
}

static unsigned long spufs_mem_mmap_nopfn(struct vm_area_struct *vma,
					  unsigned long address)
{
	struct spu_context *ctx	= vma->vm_file->private_data;
	unsigned long pfn, offset, addr0 = address;
#ifdef CONFIG_SPU_FS_64K_LS
	struct spu_state *csa = &ctx->csa;
	int psize;

	/* Check what page size we are using */
	psize = get_slice_psize(vma->vm_mm, address);

	/* Some sanity checking */
	BUG_ON(csa->use_big_pages != (psize == MMU_PAGE_64K));

	/* Wow, 64K, cool, we need to align the address though */
	if (csa->use_big_pages) {
		BUG_ON(vma->vm_start & 0xffff);
		address &= ~0xfffful;
	}
#endif /* CONFIG_SPU_FS_64K_LS */

	offset = (address - vma->vm_start) + (vma->vm_pgoff << PAGE_SHIFT);
	if (offset >= LS_SIZE)
		return NOPFN_SIGBUS;

	pr_debug("spufs_mem_mmap_nopfn address=0x%lx -> 0x%lx, offset=0x%lx\n",
		 addr0, address, offset);

	spu_acquire(ctx);

	if (ctx->state == SPU_STATE_SAVED) {
		vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
							& ~_PAGE_NO_CACHE);
		pfn = vmalloc_to_pfn(ctx->csa.lscsa->ls + offset);
	} else {
		vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
					     | _PAGE_NO_CACHE);
		pfn = (ctx->spu->local_store_phys + offset) >> PAGE_SHIFT;
	}
	vm_insert_pfn(vma, address, pfn);

	spu_release(ctx);

	return NOPFN_REFAULT;
}


static struct vm_operations_struct spufs_mem_mmap_vmops = {
	.nopfn = spufs_mem_mmap_nopfn,
};

static int spufs_mem_mmap(struct file *file, struct vm_area_struct *vma)
{
#ifdef CONFIG_SPU_FS_64K_LS
	struct spu_context	*ctx = file->private_data;
	struct spu_state	*csa = &ctx->csa;

	/* Sanity check VMA alignment */
	if (csa->use_big_pages) {
		pr_debug("spufs_mem_mmap 64K, start=0x%lx, end=0x%lx,"
			 " pgoff=0x%lx\n", vma->vm_start, vma->vm_end,
			 vma->vm_pgoff);
		if (vma->vm_start & 0xffff)
			return -EINVAL;
		if (vma->vm_pgoff & 0xf)
			return -EINVAL;
	}
#endif /* CONFIG_SPU_FS_64K_LS */

	if (!(vma->vm_flags & VM_SHARED))
		return -EINVAL;

	vma->vm_flags |= VM_IO | VM_PFNMAP;
	vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
				     | _PAGE_NO_CACHE);

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

#ifdef CONFIG_SPU_FS_64K_LS
static unsigned long spufs_get_unmapped_area(struct file *file,
		unsigned long addr, unsigned long len, unsigned long pgoff,
		unsigned long flags)
{
	struct spu_context	*ctx = file->private_data;
	struct spu_state	*csa = &ctx->csa;

	/* If not using big pages, fallback to normal MM g_u_a */
	if (!csa->use_big_pages)
		return current->mm->get_unmapped_area(file, addr, len,
						      pgoff, flags);

	/* Else, try to obtain a 64K pages slice */
	return slice_get_unmapped_area(addr, len, flags,
				       MMU_PAGE_64K, 1, 0);
}
#endif /* CONFIG_SPU_FS_64K_LS */

static const struct file_operations spufs_mem_fops = {
	.open			= spufs_mem_open,
	.release		= spufs_mem_release,
	.read			= spufs_mem_read,
	.write			= spufs_mem_write,
	.llseek			= generic_file_llseek,
	.mmap			= spufs_mem_mmap,
#ifdef CONFIG_SPU_FS_64K_LS
	.get_unmapped_area	= spufs_get_unmapped_area,
#endif
};

static unsigned long spufs_ps_nopfn(struct vm_area_struct *vma,
				    unsigned long address,
				    unsigned long ps_offs,
				    unsigned long ps_size)
{
	struct spu_context *ctx = vma->vm_file->private_data;
	unsigned long area, offset = address - vma->vm_start;
	int ret;

	offset += vma->vm_pgoff << PAGE_SHIFT;
	if (offset >= ps_size)
		return NOPFN_SIGBUS;

	/* error here usually means a signal.. we might want to test
	 * the error code more precisely though
	 */
	ret = spu_acquire_runnable(ctx, 0);
	if (ret)
		return NOPFN_REFAULT;

	area = ctx->spu->problem_phys + ps_offs;
	vm_insert_pfn(vma, address, (area + offset) >> PAGE_SHIFT);
	spu_release(ctx);

	return NOPFN_REFAULT;
}

#if SPUFS_MMAP_4K
static unsigned long spufs_cntl_mmap_nopfn(struct vm_area_struct *vma,
					   unsigned long address)
{
	return spufs_ps_nopfn(vma, address, 0x4000, 0x1000);
}

static struct vm_operations_struct spufs_cntl_mmap_vmops = {
	.nopfn = spufs_cntl_mmap_nopfn,
};

/*
 * mmap support for problem state control area [0x4000 - 0x4fff].
 */
static int spufs_cntl_mmap(struct file *file, struct vm_area_struct *vma)
{
	if (!(vma->vm_flags & VM_SHARED))
		return -EINVAL;

	vma->vm_flags |= VM_IO | VM_PFNMAP;
	vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
				     | _PAGE_NO_CACHE | _PAGE_GUARDED);

	vma->vm_ops = &spufs_cntl_mmap_vmops;
	return 0;
}
#else /* SPUFS_MMAP_4K */
#define spufs_cntl_mmap NULL
#endif /* !SPUFS_MMAP_4K */

static u64 spufs_cntl_get(void *data)
{
	struct spu_context *ctx = data;
	u64 val;

	spu_acquire(ctx);
	val = ctx->ops->status_read(ctx);
	spu_release(ctx);

	return val;
}

static void spufs_cntl_set(void *data, u64 val)
{
	struct spu_context *ctx = data;

	spu_acquire(ctx);
	ctx->ops->runcntl_write(ctx, val);
	spu_release(ctx);
}

static int spufs_cntl_open(struct inode *inode, struct file *file)
{
	struct spufs_inode_info *i = SPUFS_I(inode);
	struct spu_context *ctx = i->i_ctx;

	mutex_lock(&ctx->mapping_lock);
	file->private_data = ctx;
	if (!i->i_openers++)
		ctx->cntl = inode->i_mapping;
	mutex_unlock(&ctx->mapping_lock);
	return simple_attr_open(inode, file, spufs_cntl_get,
					spufs_cntl_set, "0x%08lx");
}

static int
spufs_cntl_release(struct inode *inode, struct file *file)
{
	struct spufs_inode_info *i = SPUFS_I(inode);
	struct spu_context *ctx = i->i_ctx;

	simple_attr_close(inode, file);

	mutex_lock(&ctx->mapping_lock);
	if (!--i->i_openers)
		ctx->cntl = NULL;
	mutex_unlock(&ctx->mapping_lock);
	return 0;
}

static const struct file_operations spufs_cntl_fops = {
	.open = spufs_cntl_open,
	.release = spufs_cntl_release,
	.read = simple_attr_read,
	.write = simple_attr_write,
	.mmap = spufs_cntl_mmap,
};

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 spu_context *ctx, char __user *buffer,
			size_t size, loff_t *pos)
{
	struct spu_lscsa *lscsa = ctx->csa.lscsa;
	return simple_read_from_buffer(buffer, size, pos,
				      lscsa->gprs, sizeof lscsa->gprs);
}

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

	spu_acquire_saved(ctx);
	ret = __spufs_regs_read(ctx, buffer, size, pos);
	spu_release_saved(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(ctx);

	ret = copy_from_user(lscsa->gprs + *pos - size,
			     buffer, size) ? -EFAULT : size;

	spu_release_saved(ctx);
	return ret;
}

static const struct file_operations spufs_regs_fops = {
	.open	 = spufs_regs_open,
	.read    = spufs_regs_read,
	.write   = spufs_regs_write,
	.llseek  = generic_file_llseek,
};

static ssize_t
__spufs_fpcr_read(struct spu_context *ctx, char __user * buffer,
			size_t size, loff_t * pos)
{
	struct spu_lscsa *lscsa = ctx->csa.lscsa;
	return simple_read_from_buffer(buffer, size, pos,
				      &lscsa->fpcr, sizeof(lscsa->fpcr));
}

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

	spu_acquire_saved(ctx);
	ret = __spufs_fpcr_read(ctx, buffer, size, pos);
	spu_release_saved(ctx);
	return ret;
}

static ssize_t
spufs_fpcr_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->fpcr) - *pos, size);
	if (size <= 0)
		return -EFBIG;
	*pos += size;

	spu_acquire_saved(ctx);

	ret = copy_from_user((char *)&lscsa->fpcr + *pos - size,
			     buffer, size) ? -EFAULT : size;

	spu_release_saved(ctx);
	return ret;
}

static const struct file_operations spufs_fpcr_fops = {
	.open = spufs_regs_open,
	.read = spufs_fpcr_read,
	.write = spufs_fpcr_write,
	.llseek = generic_file_llseek,
};

/* generic open function for all pipe-like files */
static int spufs_pipe_open(struct inode *inode, struct file *file)
{
	struct spufs_inode_info *i = SPUFS_I(inode);
	file->private_data = i->i_ctx;

	return nonseekable_open(inode, file);
}

/*
 * Read as many bytes from the mailbox as possible, until
 * one of the conditions becomes true:
 *
 * - no more data available in the mailbox
 * - end of the user provided buffer
 * - end of the mapped area
 */
static ssize_t spufs_mbox_read(struct file *file, char __user *buf,
			size_t len, loff_t *pos)
{
	struct spu_context *ctx = file->private_data;
	u32 mbox_data, __user *udata;
	ssize_t count;

	if (len < 4)
		return -EINVAL;

	if (!access_ok(VERIFY_WRITE, buf, len))
		return -EFAULT;

	udata = (void __user *)buf;

	spu_acquire(ctx);
	for (count = 0; (count + 4) <= len; count += 4, udata++) {
		int ret;
		ret = ctx->ops->mbox_read(ctx, &mbox_data);
		if (ret == 0)
			break;

		/*
		 * at the end of the mapped area, we can fault
		 * but still need to return the data we have
		 * read successfully so far.
		 */
		ret = __put_user(mbox_data, udata);
		if (ret) {
			if (!count)
				count = -EFAULT;
			break;
		}
	}
	spu_release(ctx);

	if (!count)
		count = -EAGAIN;

	return count;
}

static const struct file_operations spufs_mbox_fops = {
	.open	= spufs_pipe_open,
	.read	= spufs_mbox_read,
};

static ssize_t spufs_mbox_stat_read(struct file *file, char __user *buf,
			size_t len, loff_t *pos)
{
	struct spu_context *ctx = file->private_data;
	u32 mbox_stat;

	if (len < 4)
		return -EINVAL;

	spu_acquire(ctx);

	mbox_stat = ctx->ops->mbox_stat_read(ctx) & 0xff;

	spu_release(ctx);

	if (copy_to_user(buf, &mbox_stat, sizeof mbox_stat))
		return -EFAULT;

	return 4;
}

static const struct file_operations spufs_mbox_stat_fops = {
	.open	= spufs_pipe_open,
	.read	= spufs_mbox_stat_read,
};

/* low-level ibox access function */
size_t spu_ibox_read(struct spu_context *ctx, u32 *data)