--- /dev/null
+/*
+ * 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 <asm/uaccess.h>
+#include <platform/simcall.h>
+
+#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(SYS_lseek, dev->fd, offset, SEEK_SET, 0, 0);
+ 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)
+{
+ int i;
+ struct bio_vec *bvec;
+ sector_t sector = bio->bi_sector;
+
+ bio_for_each_segment(bvec, bio, i) {
+ char *buffer = __bio_kmap_atomic(bio, i, KM_USER0);
+ unsigned len = bvec->bv_len >> SECTOR_SHIFT;
+
+ simdisk_transfer(dev, sector, len, buffer,
+ bio_data_dir(bio) == WRITE);
+ sector += len;
+ __bio_kunmap_atomic(bio, KM_USER0);
+ }
+ 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 int simdisk_release(struct gendisk *disk, fmode_t mode)
+{
+ struct simdisk *dev = disk->private_data;
+ spin_lock(&dev->lock);
+ --dev->users;
+ spin_unlock(&dev->lock);
+ return 0;
+}
+
+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(SYS_lseek, dev->fd, 0, SEEK_END, 0, 0);
+ 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 int proc_read_simdisk(char *page, char **start, off_t off,
+ int count, int *eof, void *data)
+{
+ int len;
+ struct simdisk *dev = (struct simdisk *) data;
+ len = sprintf(page, "%s\n", dev->filename ? dev->filename : "");
+ return len;
+}
+
+static int proc_write_simdisk(struct file *file, const char *buffer,
+ unsigned long count, void *data)
+{
+ char *tmp = kmalloc(count + 1, GFP_KERNEL);
+ struct simdisk *dev = (struct simdisk *) data;
+ int err;
+
+ if (tmp == NULL)
+ return -ENOMEM;
+ if (copy_from_user(tmp, buffer, 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 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 = create_proc_entry(tmp, 0644, procdir);
+ dev->procfile->data = dev;
+ dev->procfile->read_proc = proc_read_simdisk;
+ dev->procfile->write_proc = proc_write_simdisk;
+ 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");
projects / GitHub / exynos8895 / android_kernel_samsung_universal8895.git / commitdiff