From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- arch/xtensa/platforms/iss/simdisk.c | 384 ++++++++++++++++++++++++++++++++++++ 1 file changed, 384 insertions(+) create mode 100644 arch/xtensa/platforms/iss/simdisk.c (limited to 'arch/xtensa/platforms/iss/simdisk.c') diff --git a/arch/xtensa/platforms/iss/simdisk.c b/arch/xtensa/platforms/iss/simdisk.c new file mode 100644 index 000000000..48eebacdf --- /dev/null +++ b/arch/xtensa/platforms/iss/simdisk.c @@ -0,0 +1,384 @@ +/* + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define SIMDISK_MAJOR 240 +#define SECTOR_SHIFT 9 +#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); + 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 int simdisk_xfer_bio(struct simdisk *dev, struct bio *bio) +{ + 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 = __bio_kmap_atomic(bio, iter); + unsigned len = bvec.bv_len >> SECTOR_SHIFT; + + simdisk_transfer(dev, sector, len, buffer, + bio_data_dir(bio) == WRITE); + sector += len; + __bio_kunmap_atomic(buffer); + } + return 0; +} + +static void simdisk_make_request(struct request_queue *q, struct bio *bio) +{ + struct simdisk *dev = q->queuedata; + int status = simdisk_xfer_bio(dev, bio); + bio_endio(bio, status); +} + + +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 = kmalloc(count + 1, GFP_KERNEL); + struct simdisk *dev = PDE_DATA(file_inode(file)); + int err; + + if (tmp == NULL) + return -ENOMEM; + if (copy_from_user(tmp, buf, count)) { + err = -EFAULT; + goto out_free; + } + + err = simdisk_detach(dev); + if (err != 0) + goto out_free; + + if (count > 0 && tmp[count - 1] == '\n') + tmp[count - 1] = 0; + else + tmp[count] = 0; + + if (tmp[0]) + err = simdisk_attach(dev, tmp); + + if (err == 0) + err = count; +out_free: + kfree(tmp); + return err; +} + +static const struct file_operations fops = { + .read = proc_read_simdisk, + .write = proc_write_simdisk, + .llseek = default_llseek, +}; + +static int __init simdisk_setup(struct simdisk *dev, int which, + struct proc_dir_entry *procdir) +{ + char tmp[2] = { '0' + which, 0 }; + + dev->fd = -1; + dev->filename = NULL; + spin_lock_init(&dev->lock); + dev->users = 0; + + dev->queue = blk_alloc_queue(GFP_KERNEL); + if (dev->queue == NULL) { + pr_err("blk_alloc_queue failed\n"); + goto out_alloc_queue; + } + + blk_queue_make_request(dev->queue, simdisk_make_request); + dev->queue->queuedata = dev; + + dev->gd = alloc_disk(SIMDISK_MINORS); + if (dev->gd == NULL) { + pr_err("alloc_disk failed\n"); + goto out_alloc_disk; + } + dev->gd->major = simdisk_major; + dev->gd->first_minor = which; + dev->gd->fops = &simdisk_ops; + dev->gd->queue = dev->queue; + dev->gd->private_data = dev; + snprintf(dev->gd->disk_name, 32, "simdisk%d", which); + set_capacity(dev->gd, 0); + add_disk(dev->gd); + + dev->procfile = proc_create_data(tmp, 0644, procdir, &fops, dev); + return 0; + +out_alloc_disk: + blk_cleanup_queue(dev->queue); + dev->queue = NULL; +out_alloc_queue: + simc_close(dev->fd); + return -EIO; +} + +static int __init simdisk_init(void) +{ + int i; + + if (register_blkdev(simdisk_major, "simdisk") < 0) { + pr_err("SIMDISK: register_blkdev: %d\n", simdisk_major); + return -EIO; + } + pr_info("SIMDISK: major: %d\n", simdisk_major); + + if (n_files > simdisk_count) + simdisk_count = n_files; + if (simdisk_count > MAX_SIMDISK_COUNT) + simdisk_count = MAX_SIMDISK_COUNT; + + sddev = kmalloc(simdisk_count * sizeof(struct simdisk), + GFP_KERNEL); + if (sddev == NULL) + goto out_unregister; + + simdisk_procdir = proc_mkdir("simdisk", 0); + if (simdisk_procdir == NULL) + goto out_free_unregister; + + for (i = 0; i < simdisk_count; ++i) { + if (simdisk_setup(sddev + i, i, simdisk_procdir) == 0) { + if (filename[i] != NULL && filename[i][0] != 0 && + (n_files == 0 || i < n_files)) + simdisk_attach(sddev + i, filename[i]); + } + } + + return 0; + +out_free_unregister: + kfree(sddev); +out_unregister: + unregister_blkdev(simdisk_major, "simdisk"); + return -ENOMEM; +} +module_init(simdisk_init); + +static void simdisk_teardown(struct simdisk *dev, int which, + struct proc_dir_entry *procdir) +{ + char tmp[2] = { '0' + which, 0 }; + + simdisk_detach(dev); + if (dev->gd) + del_gendisk(dev->gd); + if (dev->queue) + blk_cleanup_queue(dev->queue); + remove_proc_entry(tmp, procdir); +} + +static void __exit simdisk_exit(void) +{ + int i; + + for (i = 0; i < simdisk_count; ++i) + simdisk_teardown(sddev + i, i, simdisk_procdir); + remove_proc_entry("simdisk", 0); + kfree(sddev); + unregister_blkdev(simdisk_major, "simdisk"); +} +module_exit(simdisk_exit); + +MODULE_ALIAS_BLOCKDEV_MAJOR(SIMDISK_MAJOR); + +MODULE_LICENSE("GPL"); -- cgit v1.2.3-54-g00ecf