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-rw-r--r--arch/xtensa/platforms/iss/simdisk.c366
1 files changed, 366 insertions, 0 deletions
diff --git a/arch/xtensa/platforms/iss/simdisk.c b/arch/xtensa/platforms/iss/simdisk.c
new file mode 100644
index 000000000..f50caaa1c
--- /dev/null
+++ b/arch/xtensa/platforms/iss/simdisk.c
@@ -0,0 +1,366 @@
+/*
+ * 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 <linux/uaccess.h>
+#include <platform/simcall.h>
+
+#define SIMDISK_MAJOR 240
+#define SIMDISK_MINORS 1
+#define MAX_SIMDISK_COUNT 10
+
+struct simdisk {
+ const char *filename;
+ spinlock_t lock;
+ 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);
+ READ_ONCE(*buffer);
+ 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 void simdisk_submit_bio(struct bio *bio)
+{
+ struct simdisk *dev = bio->bi_bdev->bd_disk->private_data;
+ 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 = bvec_kmap_local(&bvec);
+ unsigned len = bvec.bv_len >> SECTOR_SHIFT;
+
+ simdisk_transfer(dev, sector, len, buffer,
+ bio_data_dir(bio) == WRITE);
+ sector += len;
+ kunmap_local(buffer);
+ }
+
+ bio_endio(bio);
+}
+
+static int simdisk_open(struct block_device *bdev, fmode_t mode)
+{
+ struct simdisk *dev = bdev->bd_disk->private_data;
+
+ spin_lock(&dev->lock);
+ ++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,
+ .submit_bio = simdisk_submit_bio,
+ .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 len = strlen(s);
+ char *temp = kmalloc(len + 2, GFP_KERNEL);
+
+ if (!temp)
+ return -ENOMEM;
+
+ len = scnprintf(temp, len + 2, "%s\n", s);
+ len = simple_read_from_buffer(buf, size, ppos,
+ temp, len);
+
+ kfree(temp);
+ return len;
+ }
+ 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 = memdup_user_nul(buf, count);
+ struct simdisk *dev = pde_data(file_inode(file));
+ int err;
+
+ if (IS_ERR(tmp))
+ return PTR_ERR(tmp);
+
+ err = simdisk_detach(dev);
+ if (err != 0)
+ goto out_free;
+
+ if (count > 0 && tmp[count - 1] == '\n')
+ tmp[count - 1] = 0;
+
+ if (tmp[0])
+ err = simdisk_attach(dev, tmp);
+
+ if (err == 0)
+ err = count;
+out_free:
+ kfree(tmp);
+ return err;
+}
+
+static const struct proc_ops simdisk_proc_ops = {
+ .proc_read = proc_read_simdisk,
+ .proc_write = proc_write_simdisk,
+ .proc_lseek = default_llseek,
+};
+
+static int __init simdisk_setup(struct simdisk *dev, int which,
+ struct proc_dir_entry *procdir)
+{
+ char tmp[2] = { '0' + which, 0 };
+ int err = -ENOMEM;
+
+ dev->fd = -1;
+ dev->filename = NULL;
+ spin_lock_init(&dev->lock);
+ dev->users = 0;
+
+ dev->gd = blk_alloc_disk(NUMA_NO_NODE);
+ if (!dev->gd)
+ goto out;
+ dev->gd->major = simdisk_major;
+ dev->gd->first_minor = which;
+ dev->gd->minors = SIMDISK_MINORS;
+ dev->gd->fops = &simdisk_ops;
+ dev->gd->private_data = dev;
+ snprintf(dev->gd->disk_name, 32, "simdisk%d", which);
+ set_capacity(dev->gd, 0);
+ err = add_disk(dev->gd);
+ if (err)
+ goto out_cleanup_disk;
+
+ dev->procfile = proc_create_data(tmp, 0644, procdir, &simdisk_proc_ops, dev);
+
+ return 0;
+
+out_cleanup_disk:
+ put_disk(dev->gd);
+out:
+ return err;
+}
+
+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_array(simdisk_count, sizeof(*sddev), 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);
+ put_disk(dev->gd);
+ }
+ 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");