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 <linux/uaccess.h>
21 #include <platform/simcall.h>
23 #define SIMDISK_MAJOR 240
24 #define SIMDISK_MINORS 1
25 #define MAX_SIMDISK_COUNT 10
31 struct proc_dir_entry *procfile;
38 static int simdisk_count = CONFIG_BLK_DEV_SIMDISK_COUNT;
39 module_param(simdisk_count, int, S_IRUGO);
40 MODULE_PARM_DESC(simdisk_count, "Number of simdisk units.");
43 static const char *filename[MAX_SIMDISK_COUNT] = {
44 #ifdef CONFIG_SIMDISK0_FILENAME
45 CONFIG_SIMDISK0_FILENAME,
46 #ifdef CONFIG_SIMDISK1_FILENAME
47 CONFIG_SIMDISK1_FILENAME,
52 static int simdisk_param_set_filename(const char *val,
53 const struct kernel_param *kp)
55 if (n_files < ARRAY_SIZE(filename))
56 filename[n_files++] = val;
62 static const struct kernel_param_ops simdisk_param_ops_filename = {
63 .set = simdisk_param_set_filename,
65 module_param_cb(filename, &simdisk_param_ops_filename, &n_files, 0);
66 MODULE_PARM_DESC(filename, "Backing storage filename.");
68 static int simdisk_major = SIMDISK_MAJOR;
70 static void simdisk_transfer(struct simdisk *dev, unsigned long sector,
71 unsigned long nsect, char *buffer, int write)
73 unsigned long offset = sector << SECTOR_SHIFT;
74 unsigned long nbytes = nsect << SECTOR_SHIFT;
76 if (offset > dev->size || dev->size - offset < nbytes) {
77 pr_notice("Beyond-end %s (%ld %ld)\n",
78 write ? "write" : "read", offset, nbytes);
82 spin_lock(&dev->lock);
86 simc_lseek(dev->fd, offset, SEEK_SET);
89 io = simc_write(dev->fd, buffer, nbytes);
91 io = simc_read(dev->fd, buffer, nbytes);
93 pr_err("SIMDISK: IO error %d\n", errno);
100 spin_unlock(&dev->lock);
103 static void simdisk_submit_bio(struct bio *bio)
105 struct simdisk *dev = bio->bi_bdev->bd_disk->private_data;
107 struct bvec_iter iter;
108 sector_t sector = bio->bi_iter.bi_sector;
110 bio_for_each_segment(bvec, bio, iter) {
111 char *buffer = kmap_atomic(bvec.bv_page) + bvec.bv_offset;
112 unsigned len = bvec.bv_len >> SECTOR_SHIFT;
114 simdisk_transfer(dev, sector, len, buffer,
115 bio_data_dir(bio) == WRITE);
117 kunmap_atomic(buffer);
123 static int simdisk_open(struct block_device *bdev, fmode_t mode)
125 struct simdisk *dev = bdev->bd_disk->private_data;
127 spin_lock(&dev->lock);
129 spin_unlock(&dev->lock);
133 static void simdisk_release(struct gendisk *disk, fmode_t mode)
135 struct simdisk *dev = disk->private_data;
136 spin_lock(&dev->lock);
138 spin_unlock(&dev->lock);
141 static const struct block_device_operations simdisk_ops = {
142 .owner = THIS_MODULE,
143 .submit_bio = simdisk_submit_bio,
144 .open = simdisk_open,
145 .release = simdisk_release,
148 static struct simdisk *sddev;
149 static struct proc_dir_entry *simdisk_procdir;
151 static int simdisk_attach(struct simdisk *dev, const char *filename)
155 filename = kstrdup(filename, GFP_KERNEL);
156 if (filename == NULL)
159 spin_lock(&dev->lock);
165 dev->fd = simc_open(filename, O_RDWR, 0);
167 pr_err("SIMDISK: Can't open %s: %d\n", filename, errno);
171 dev->size = simc_lseek(dev->fd, 0, SEEK_END);
172 set_capacity(dev->gd, dev->size >> SECTOR_SHIFT);
173 dev->filename = filename;
174 pr_info("SIMDISK: %s=%s\n", dev->gd->disk_name, dev->filename);
178 spin_unlock(&dev->lock);
183 static int simdisk_detach(struct simdisk *dev)
187 spin_lock(&dev->lock);
189 if (dev->users != 0) {
191 } else if (dev->fd != -1) {
192 if (simc_close(dev->fd)) {
193 pr_err("SIMDISK: error closing %s: %d\n",
194 dev->filename, errno);
197 pr_info("SIMDISK: %s detached from %s\n",
198 dev->gd->disk_name, dev->filename);
200 kfree(dev->filename);
201 dev->filename = NULL;
204 spin_unlock(&dev->lock);
208 static ssize_t proc_read_simdisk(struct file *file, char __user *buf,
209 size_t size, loff_t *ppos)
211 struct simdisk *dev = PDE_DATA(file_inode(file));
212 const char *s = dev->filename;
214 ssize_t n = simple_read_from_buffer(buf, size, ppos,
221 return simple_read_from_buffer(buf, size, ppos, "\n", 1);
224 static ssize_t proc_write_simdisk(struct file *file, const char __user *buf,
225 size_t count, loff_t *ppos)
227 char *tmp = memdup_user_nul(buf, count);
228 struct simdisk *dev = PDE_DATA(file_inode(file));
234 err = simdisk_detach(dev);
238 if (count > 0 && tmp[count - 1] == '\n')
242 err = simdisk_attach(dev, tmp);
251 static const struct proc_ops simdisk_proc_ops = {
252 .proc_read = proc_read_simdisk,
253 .proc_write = proc_write_simdisk,
254 .proc_lseek = default_llseek,
257 static int __init simdisk_setup(struct simdisk *dev, int which,
258 struct proc_dir_entry *procdir)
260 char tmp[2] = { '0' + which, 0 };
264 dev->filename = NULL;
265 spin_lock_init(&dev->lock);
268 dev->gd = blk_alloc_disk(NUMA_NO_NODE);
271 dev->gd->major = simdisk_major;
272 dev->gd->first_minor = which;
273 dev->gd->minors = SIMDISK_MINORS;
274 dev->gd->fops = &simdisk_ops;
275 dev->gd->private_data = dev;
276 snprintf(dev->gd->disk_name, 32, "simdisk%d", which);
277 set_capacity(dev->gd, 0);
278 err = add_disk(dev->gd);
280 goto out_cleanup_disk;
282 dev->procfile = proc_create_data(tmp, 0644, procdir, &simdisk_proc_ops, dev);
287 blk_cleanup_disk(dev->gd);
292 static int __init simdisk_init(void)
296 if (register_blkdev(simdisk_major, "simdisk") < 0) {
297 pr_err("SIMDISK: register_blkdev: %d\n", simdisk_major);
300 pr_info("SIMDISK: major: %d\n", simdisk_major);
302 if (n_files > simdisk_count)
303 simdisk_count = n_files;
304 if (simdisk_count > MAX_SIMDISK_COUNT)
305 simdisk_count = MAX_SIMDISK_COUNT;
307 sddev = kmalloc_array(simdisk_count, sizeof(*sddev), GFP_KERNEL);
311 simdisk_procdir = proc_mkdir("simdisk", 0);
312 if (simdisk_procdir == NULL)
313 goto out_free_unregister;
315 for (i = 0; i < simdisk_count; ++i) {
316 if (simdisk_setup(sddev + i, i, simdisk_procdir) == 0) {
317 if (filename[i] != NULL && filename[i][0] != 0 &&
318 (n_files == 0 || i < n_files))
319 simdisk_attach(sddev + i, filename[i]);
328 unregister_blkdev(simdisk_major, "simdisk");
331 module_init(simdisk_init);
333 static void simdisk_teardown(struct simdisk *dev, int which,
334 struct proc_dir_entry *procdir)
336 char tmp[2] = { '0' + which, 0 };
340 del_gendisk(dev->gd);
341 blk_cleanup_disk(dev->gd);
343 remove_proc_entry(tmp, procdir);
346 static void __exit simdisk_exit(void)
350 for (i = 0; i < simdisk_count; ++i)
351 simdisk_teardown(sddev + i, i, simdisk_procdir);
352 remove_proc_entry("simdisk", 0);
354 unregister_blkdev(simdisk_major, "simdisk");
356 module_exit(simdisk_exit);
358 MODULE_ALIAS_BLOCKDEV_MAJOR(SIMDISK_MAJOR);
360 MODULE_LICENSE("GPL");