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/*
* arch/xtensa/platforms/iss/simdisk.c
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2001-2013 Tensilica Inc.
* Authors Victor Prupis
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/blkdev.h>
#include <linux/bio.h>
#include <linux/proc_fs.h>
#include <linux/uaccess.h>
#include <platform/simcall.h>
#define SIMDISK_MAJOR 240
#define SIMDISK_MINORS 1
#define MAX_SIMDISK_COUNT 10
struct simdisk {
const char *filename;
spinlock_t lock;
struct request_queue *queue;
struct gendisk *gd;
struct proc_dir_entry *procfile;
int users;
unsigned long size;
int fd;
};
static int simdisk_count = CONFIG_BLK_DEV_SIMDISK_COUNT;
module_param(simdisk_count, int, S_IRUGO);
MODULE_PARM_DESC(simdisk_count, "Number of simdisk units.");
static int n_files;
static const char *filename[MAX_SIMDISK_COUNT] = {
#ifdef CONFIG_SIMDISK0_FILENAME
CONFIG_SIMDISK0_FILENAME,
#ifdef CONFIG_SIMDISK1_FILENAME
CONFIG_SIMDISK1_FILENAME,
#endif
#endif
};
static int simdisk_param_set_filename(const char *val,
const struct kernel_param *kp)
{
if (n_files < ARRAY_SIZE(filename))
filename[n_files++] = val;
else
return -EINVAL;
return 0;
}
static const struct kernel_param_ops simdisk_param_ops_filename = {
.set = simdisk_param_set_filename,
};
module_param_cb(filename, &simdisk_param_ops_filename, &n_files, 0);
MODULE_PARM_DESC(filename, "Backing storage filename.");
static int simdisk_major = SIMDISK_MAJOR;
static void simdisk_transfer(struct simdisk *dev, unsigned long sector,
unsigned long nsect, char *buffer, int write)
{
unsigned long offset = sector << SECTOR_SHIFT;
unsigned long nbytes = nsect << SECTOR_SHIFT;
if (offset > dev->size || dev->size - offset < nbytes) {
pr_notice("Beyond-end %s (%ld %ld)\n",
write ? "write" : "read", offset, nbytes);
return;
}
spin_lock(&dev->lock);
while (nbytes > 0) {
unsigned long io;
simc_lseek(dev->fd, offset, SEEK_SET);
READ_ONCE(*buffer);
if (write)
io = simc_write(dev->fd, buffer, nbytes);
else
io = simc_read(dev->fd, buffer, nbytes);
if (io == -1) {
pr_err("SIMDISK: IO error %d\n", errno);
break;
}
buffer += io;
offset += io;
nbytes -= io;
}
spin_unlock(&dev->lock);
}
static blk_qc_t simdisk_make_request(struct request_queue *q, struct bio *bio)
{
struct simdisk *dev = q->queuedata;
struct bio_vec bvec;
struct bvec_iter iter;
sector_t sector = bio->bi_iter.bi_sector;
bio_for_each_segment(bvec, bio, iter) {
char *buffer = kmap_atomic(bvec.bv_page) + bvec.bv_offset;
unsigned len = bvec.bv_len >> SECTOR_SHIFT;
simdisk_transfer(dev, sector, len, buffer,
bio_data_dir(bio) == WRITE);
sector += len;
kunmap_atomic(buffer);
}
bio_endio(bio);
return BLK_QC_T_NONE;
}
static int simdisk_open(struct block_device *bdev, fmode_t mode)
{
struct simdisk *dev = bdev->bd_disk->private_data;
spin_lock(&dev->lock);
if (!dev->users)
check_disk_change(bdev);
++dev->users;
spin_unlock(&dev->lock);
return 0;
}
static void simdisk_release(struct gendisk *disk, fmode_t mode)
{
struct simdisk *dev = disk->private_data;
spin_lock(&dev->lock);
--dev->users;
spin_unlock(&dev->lock);
}
static const struct block_device_operations simdisk_ops = {
.owner = THIS_MODULE,
.open = simdisk_open,
.release = simdisk_release,
};
static struct simdisk *sddev;
static struct proc_dir_entry *simdisk_procdir;
static int simdisk_attach(struct simdisk *dev, const char *filename)
{
int err = 0;
filename = kstrdup(filename, GFP_KERNEL);
if (filename == NULL)
return -ENOMEM;
spin_lock(&dev->lock);
if (dev->fd != -1) {
err = -EBUSY;
goto out;
}
dev->fd = simc_open(filename, O_RDWR, 0);
if (dev->fd == -1) {
pr_err("SIMDISK: Can't open %s: %d\n", filename, errno);
err = -ENODEV;
goto out;
}
dev->size = simc_lseek(dev->fd, 0, SEEK_END);
set_capacity(dev->gd, dev->size >> SECTOR_SHIFT);
dev->filename = filename;
pr_info("SIMDISK: %s=%s\n", dev->gd->disk_name, dev->filename);
out:
if (err)
kfree(filename);
spin_unlock(&dev->lock);
return err;
}
static int simdisk_detach(struct simdisk *dev)
{
int err = 0;
spin_lock(&dev->lock);
if (dev->users != 0) {
err = -EBUSY;
} else if (dev->fd != -1) {
if (simc_close(dev->fd)) {
pr_err("SIMDISK: error closing %s: %d\n",
dev->filename, errno);
err = -EIO;
} else {
pr_info("SIMDISK: %s detached from %s\n",
dev->gd->disk_name, dev->filename);
dev->fd = -1;
kfree(dev->filename);
dev->filename = NULL;
}
}
spin_unlock(&dev->lock);
return err;
}
static ssize_t proc_read_simdisk(struct file *file, char __user *buf,
size_t size, loff_t *ppos)
{
struct simdisk *dev = PDE_DATA(file_inode(file));
const char *s = dev->filename;
if (s) {
ssize_t n = simple_read_from_buffer(buf, size, ppos,
s, strlen(s));
if (n < 0)
return n;
buf += n;
size -= n;
}
return simple_read_from_buffer(buf, size, ppos, "\n", 1);
}
static ssize_t proc_write_simdisk(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
char *tmp = memdup_user_nul(buf, count);
struct simdisk *dev = PDE_DATA(file_inode(file));
int err;
if (IS_ERR(tmp))
return PTR_ERR(tmp);
err = simdisk_detach(dev);
if (err != 0)
goto out_free;
if (count > 0 && tmp[count - 1] == '\n')
tmp[count - 1] = 0;
if (tmp[0])
err = simdisk_attach(dev, tmp);
if (err == 0)
err
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