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
30 struct request_queue *queue;
32 struct proc_dir_entry *procfile;
39 static int simdisk_count = CONFIG_BLK_DEV_SIMDISK_COUNT;
40 module_param(simdisk_count, int, S_IRUGO);
41 MODULE_PARM_DESC(simdisk_count, "Number of simdisk units.");
44 static const char *filename[MAX_SIMDISK_COUNT] = {
45 #ifdef CONFIG_SIMDISK0_FILENAME
46 CONFIG_SIMDISK0_FILENAME,
47 #ifdef CONFIG_SIMDISK1_FILENAME
48 CONFIG_SIMDISK1_FILENAME,
53 static int simdisk_param_set_filename(const char *val,
54 const struct kernel_param *kp)
56 if (n_files < ARRAY_SIZE(filename))
57 filename[n_files++] = val;
63 static const struct kernel_param_ops simdisk_param_ops_filename = {
64 .set = simdisk_param_set_filename,
66 module_param_cb(filename, &simdisk_param_ops_filename, &n_files, 0);
67 MODULE_PARM_DESC(filename, "Backing storage filename.");
69 static int simdisk_major = SIMDISK_MAJOR;
71 static void simdisk_transfer(struct simdisk *dev, unsigned long sector,
72 unsigned long nsect, char *buffer, int write)
74 unsigned long offset = sector << SECTOR_SHIFT;
75 unsigned long nbytes = nsect << SECTOR_SHIFT;
77 if (offset > dev->size || dev->size - offset < nbytes) {
78 pr_notice("Beyond-end %s (%ld %ld)\n",
79 write ? "write" : "read", offset, nbytes);
83 spin_lock(&dev->lock);
87 simc_lseek(dev->fd, offset, SEEK_SET);
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 blk_qc_t simdisk_submit_bio(struct bio *bio)
106 struct simdisk *dev = bio->bi_disk->private_data;
108 struct bvec_iter iter;
109 sector_t sector = bio->bi_iter.bi_sector;
111 bio_for_each_segment(bvec, bio, iter) {
112 char *buffer = kmap_atomic(bvec.bv_page) + bvec.bv_offset;
113 unsigned len = bvec.bv_len >> SECTOR_SHIFT;
115 simdisk_transfer(dev, sector, len, buffer,
116 bio_data_dir(bio) == WRITE);
118 kunmap_atomic(buffer);
122 return BLK_QC_T_NONE;
125 static int simdisk_open(struct block_device *bdev, fmode_t mode)
127 struct simdisk *dev = bdev->bd_disk->private_data;
129 spin_lock(&dev->lock);
131 check_disk_change(bdev);
133 spin_unlock(&dev->lock);
137 static void simdisk_release(struct gendisk *disk, fmode_t mode)
139 struct simdisk *dev = disk->private_data;
140 spin_lock(&dev->lock);
142 spin_unlock(&dev->lock);
145 static const struct block_device_operations simdisk_ops = {
146 .owner = THIS_MODULE,
147 .submit_bio = simdisk_submit_bio,
148 .open = simdisk_open,
149 .release = simdisk_release,
152 static struct simdisk *sddev;
153 static struct proc_dir_entry *simdisk_procdir;
155 static int simdisk_attach(struct simdisk *dev, const char *filename)
159 filename = kstrdup(filename, GFP_KERNEL);
160 if (filename == NULL)
163 spin_lock(&dev->lock);
169 dev->fd = simc_open(filename, O_RDWR, 0);
171 pr_err("SIMDISK: Can't open %s: %d\n", filename, errno);
175 dev->size = simc_lseek(dev->fd, 0, SEEK_END);
176 set_capacity(dev->gd, dev->size >> SECTOR_SHIFT);
177 dev->filename = filename;
178 pr_info("SIMDISK: %s=%s\n", dev->gd->disk_name, dev->filename);
182 spin_unlock(&dev->lock);
187 static int simdisk_detach(struct simdisk *dev)
191 spin_lock(&dev->lock);
193 if (dev->users != 0) {
195 } else if (dev->fd != -1) {
196 if (simc_close(dev->fd)) {
197 pr_err("SIMDISK: error closing %s: %d\n",
198 dev->filename, errno);
201 pr_info("SIMDISK: %s detached from %s\n",
202 dev->gd->disk_name, dev->filename);
204 kfree(dev->filename);
205 dev->filename = NULL;
208 spin_unlock(&dev->lock);
212 static ssize_t proc_read_simdisk(struct file *file, char __user *buf,
213 size_t size, loff_t *ppos)
215 struct simdisk *dev = PDE_DATA(file_inode(file));
216 const char *s = dev->filename;
218 ssize_t n = simple_read_from_buffer(buf, size, ppos,
225 return simple_read_from_buffer(buf, size, ppos, "\n", 1);
228 static ssize_t proc_write_simdisk(struct file *file, const char __user *buf,
229 size_t count, loff_t *ppos)
231 char *tmp = memdup_user_nul(buf, count);
232 struct simdisk *dev = PDE_DATA(file_inode(file));
238 err = simdisk_detach(dev);
242 if (count > 0 && tmp[count - 1] == '\n')
246 err = simdisk_attach(dev, tmp);
255 static const struct proc_ops simdisk_proc_ops = {
256 .proc_read = proc_read_simdisk,
257 .proc_write = proc_write_simdisk,
258 .proc_lseek = default_llseek,
261 static int __init simdisk_setup(struct simdisk *dev, int which,
262 struct proc_dir_entry *procdir)
264 char tmp[2] = { '0' + which, 0 };
267 dev->filename = NULL;
268 spin_lock_init(&dev->lock);
271 dev->queue = blk_alloc_queue(NUMA_NO_NODE);
272 if (dev->queue == NULL) {
273 pr_err("blk_alloc_queue failed\n");
274 goto out_alloc_queue;
277 dev->gd = alloc_disk(SIMDISK_MINORS);
278 if (dev->gd == NULL) {
279 pr_err("alloc_disk failed\n");
282 dev->gd->major = simdisk_major;
283 dev->gd->first_minor = which;
284 dev->gd->fops = &simdisk_ops;
285 dev->gd->queue = dev->queue;
286 dev->gd->private_data = dev;
287 snprintf(dev->gd->disk_name, 32, "simdisk%d", which);
288 set_capacity(dev->gd, 0);
291 dev->procfile = proc_create_data(tmp, 0644, procdir, &simdisk_proc_ops, dev);
295 blk_cleanup_queue(dev->queue);
301 static int __init simdisk_init(void)
305 if (register_blkdev(simdisk_major, "simdisk") < 0) {
306 pr_err("SIMDISK: register_blkdev: %d\n", simdisk_major);
309 pr_info("SIMDISK: major: %d\n", simdisk_major);
311 if (n_files > simdisk_count)
312 simdisk_count = n_files;
313 if (simdisk_count > MAX_SIMDISK_COUNT)
314 simdisk_count = MAX_SIMDISK_COUNT;
316 sddev = kmalloc_array(simdisk_count, sizeof(*sddev), GFP_KERNEL);
320 simdisk_procdir = proc_mkdir("simdisk", 0);
321 if (simdisk_procdir == NULL)
322 goto out_free_unregister;
324 for (i = 0; i < simdisk_count; ++i) {
325 if (simdisk_setup(sddev + i, i, simdisk_procdir) == 0) {
326 if (filename[i] != NULL && filename[i][0] != 0 &&
327 (n_files == 0 || i < n_files))
328 simdisk_attach(sddev + i, filename[i]);
337 unregister_blkdev(simdisk_major, "simdisk");
340 module_init(simdisk_init);
342 static void simdisk_teardown(struct simdisk *dev, int which,
343 struct proc_dir_entry *procdir)
345 char tmp[2] = { '0' + which, 0 };
349 del_gendisk(dev->gd);
351 blk_cleanup_queue(dev->queue);
352 remove_proc_entry(tmp, procdir);
355 static void __exit simdisk_exit(void)
359 for (i = 0; i < simdisk_count; ++i)
360 simdisk_teardown(sddev + i, i, simdisk_procdir);
361 remove_proc_entry("simdisk", 0);
363 unregister_blkdev(simdisk_major, "simdisk");
365 module_exit(simdisk_exit);
367 MODULE_ALIAS_BLOCKDEV_MAJOR(SIMDISK_MAJOR);
369 MODULE_LICENSE("GPL");