2 * arch/xtensa/platforms/iss/simdisk.c
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive
8 * Copyright (C) 2001-2013 Tensilica Inc.
9 * Authors Victor Prupis
12 #include <linux/module.h>
13 #include <linux/moduleparam.h>
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/string.h>
17 #include <linux/blkdev.h>
18 #include <linux/bio.h>
19 #include <linux/proc_fs.h>
20 #include <asm/uaccess.h>
21 #include <platform/simcall.h>
23 #define SIMDISK_MAJOR 240
24 #define SECTOR_SHIFT 9
25 #define SIMDISK_MINORS 1
26 #define MAX_SIMDISK_COUNT 10
31 struct request_queue *queue;
33 struct proc_dir_entry *procfile;
40 static int simdisk_count = CONFIG_BLK_DEV_SIMDISK_COUNT;
41 module_param(simdisk_count, int, S_IRUGO);
42 MODULE_PARM_DESC(simdisk_count, "Number of simdisk units.");
45 static const char *filename[MAX_SIMDISK_COUNT] = {
46 #ifdef CONFIG_SIMDISK0_FILENAME
47 CONFIG_SIMDISK0_FILENAME,
48 #ifdef CONFIG_SIMDISK1_FILENAME
49 CONFIG_SIMDISK1_FILENAME,
54 static int simdisk_param_set_filename(const char *val,
55 const struct kernel_param *kp)
57 if (n_files < ARRAY_SIZE(filename))
58 filename[n_files++] = val;
64 static const struct kernel_param_ops simdisk_param_ops_filename = {
65 .set = simdisk_param_set_filename,
67 module_param_cb(filename, &simdisk_param_ops_filename, &n_files, 0);
68 MODULE_PARM_DESC(filename, "Backing storage filename.");
70 static int simdisk_major = SIMDISK_MAJOR;
72 static void simdisk_transfer(struct simdisk *dev, unsigned long sector,
73 unsigned long nsect, char *buffer, int write)
75 unsigned long offset = sector << SECTOR_SHIFT;
76 unsigned long nbytes = nsect << SECTOR_SHIFT;
78 if (offset > dev->size || dev->size - offset < nbytes) {
79 pr_notice("Beyond-end %s (%ld %ld)\n",
80 write ? "write" : "read", offset, nbytes);
84 spin_lock(&dev->lock);
88 __simc(SYS_lseek, dev->fd, offset, SEEK_SET, 0, 0);
90 io = simc_write(dev->fd, buffer, nbytes);
92 io = simc_read(dev->fd, buffer, nbytes);
94 pr_err("SIMDISK: IO error %d\n", errno);
101 spin_unlock(&dev->lock);
104 static int simdisk_xfer_bio(struct simdisk *dev, struct bio *bio)
107 struct bio_vec *bvec;
108 sector_t sector = bio->bi_sector;
110 bio_for_each_segment(bvec, bio, i) {
111 char *buffer = __bio_kmap_atomic(bio, i, KM_USER0);
112 unsigned len = bvec->bv_len >> SECTOR_SHIFT;
114 simdisk_transfer(dev, sector, len, buffer,
115 bio_data_dir(bio) == WRITE);
117 __bio_kunmap_atomic(bio, KM_USER0);
122 static void simdisk_make_request(struct request_queue *q, struct bio *bio)
124 struct simdisk *dev = q->queuedata;
125 int status = simdisk_xfer_bio(dev, bio);
126 bio_endio(bio, status);
130 static int simdisk_open(struct block_device *bdev, fmode_t mode)
132 struct simdisk *dev = bdev->bd_disk->private_data;
134 spin_lock(&dev->lock);
136 check_disk_change(bdev);
138 spin_unlock(&dev->lock);
142 static int simdisk_release(struct gendisk *disk, fmode_t mode)
144 struct simdisk *dev = disk->private_data;
145 spin_lock(&dev->lock);
147 spin_unlock(&dev->lock);
151 static const struct block_device_operations simdisk_ops = {
152 .owner = THIS_MODULE,
153 .open = simdisk_open,
154 .release = simdisk_release,
157 static struct simdisk *sddev;
158 static struct proc_dir_entry *simdisk_procdir;
160 static int simdisk_attach(struct simdisk *dev, const char *filename)
164 filename = kstrdup(filename, GFP_KERNEL);
165 if (filename == NULL)
168 spin_lock(&dev->lock);
174 dev->fd = simc_open(filename, O_RDWR, 0);
176 pr_err("SIMDISK: Can't open %s: %d\n", filename, errno);
180 dev->size = __simc(SYS_lseek, dev->fd, 0, SEEK_END, 0, 0);
181 set_capacity(dev->gd, dev->size >> SECTOR_SHIFT);
182 dev->filename = filename;
183 pr_info("SIMDISK: %s=%s\n", dev->gd->disk_name, dev->filename);
187 spin_unlock(&dev->lock);
192 static int simdisk_detach(struct simdisk *dev)
196 spin_lock(&dev->lock);
198 if (dev->users != 0) {
200 } else if (dev->fd != -1) {
201 if (simc_close(dev->fd)) {
202 pr_err("SIMDISK: error closing %s: %d\n",
203 dev->filename, errno);
206 pr_info("SIMDISK: %s detached from %s\n",
207 dev->gd->disk_name, dev->filename);
209 kfree(dev->filename);
210 dev->filename = NULL;
213 spin_unlock(&dev->lock);
217 static ssize_t proc_read_simdisk(struct file *file, char __user *buf,
218 size_t size, loff_t *ppos)
220 struct simdisk *dev = PDE_DATA(file_inode(file));
221 char *s = dev->filename;
223 ssize_t n = simple_read_from_buffer(buf, size, ppos,
230 return simple_read_from_buffer(buf, size, ppos, "\n", 1);
233 static ssize_t proc_write_simdisk(struct file *file, const char __user *buf,
234 size_t count, loff_t *ppos)
236 char *tmp = kmalloc(count + 1, GFP_KERNEL);
237 struct simdisk *dev = PDE_DATA(file_inode(file));
242 if (copy_from_user(tmp, buffer, count)) {
247 err = simdisk_detach(dev);
251 if (count > 0 && tmp[count - 1] == '\n')
257 err = simdisk_attach(dev, tmp);
266 static const struct file_operations fops = {
267 .read = proc_read_simdisk,
268 .write = proc_write_simdisk,
269 .llseek = default_llseek,
272 static int __init simdisk_setup(struct simdisk *dev, int which,
273 struct proc_dir_entry *procdir)
275 char tmp[2] = { '0' + which, 0 };
278 dev->filename = NULL;
279 spin_lock_init(&dev->lock);
282 dev->queue = blk_alloc_queue(GFP_KERNEL);
283 if (dev->queue == NULL) {
284 pr_err("blk_alloc_queue failed\n");
285 goto out_alloc_queue;
288 blk_queue_make_request(dev->queue, simdisk_make_request);
289 dev->queue->queuedata = dev;
291 dev->gd = alloc_disk(SIMDISK_MINORS);
292 if (dev->gd == NULL) {
293 pr_err("alloc_disk failed\n");
296 dev->gd->major = simdisk_major;
297 dev->gd->first_minor = which;
298 dev->gd->fops = &simdisk_ops;
299 dev->gd->queue = dev->queue;
300 dev->gd->private_data = dev;
301 snprintf(dev->gd->disk_name, 32, "simdisk%d", which);
302 set_capacity(dev->gd, 0);
305 dev->procfile = proc_create_data(tmp, 0644, procdir, &fops, dev);
309 blk_cleanup_queue(dev->queue);
316 static int __init simdisk_init(void)
320 if (register_blkdev(simdisk_major, "simdisk") < 0) {
321 pr_err("SIMDISK: register_blkdev: %d\n", simdisk_major);
324 pr_info("SIMDISK: major: %d\n", simdisk_major);
326 if (n_files > simdisk_count)
327 simdisk_count = n_files;
328 if (simdisk_count > MAX_SIMDISK_COUNT)
329 simdisk_count = MAX_SIMDISK_COUNT;
331 sddev = kmalloc(simdisk_count * sizeof(struct simdisk),
336 simdisk_procdir = proc_mkdir("simdisk", 0);
337 if (simdisk_procdir == NULL)
338 goto out_free_unregister;
340 for (i = 0; i < simdisk_count; ++i) {
341 if (simdisk_setup(sddev + i, i, simdisk_procdir) == 0) {
342 if (filename[i] != NULL && filename[i][0] != 0 &&
343 (n_files == 0 || i < n_files))
344 simdisk_attach(sddev + i, filename[i]);
353 unregister_blkdev(simdisk_major, "simdisk");
356 module_init(simdisk_init);
358 static void simdisk_teardown(struct simdisk *dev, int which,
359 struct proc_dir_entry *procdir)
361 char tmp[2] = { '0' + which, 0 };
365 del_gendisk(dev->gd);
367 blk_cleanup_queue(dev->queue);
368 remove_proc_entry(tmp, procdir);
371 static void __exit simdisk_exit(void)
375 for (i = 0; i < simdisk_count; ++i)
376 simdisk_teardown(sddev + i, i, simdisk_procdir);
377 remove_proc_entry("simdisk", 0);
379 unregister_blkdev(simdisk_major, "simdisk");
381 module_exit(simdisk_exit);
383 MODULE_ALIAS_BLOCKDEV_MAJOR(SIMDISK_MAJOR);
385 MODULE_LICENSE("GPL");