2 files changed, 376 insertions, 0 deletions

diff --git a/arch/xtensa/platforms/iss/Makefile b/arch/xtensa/platforms/iss/Makefile
index b7d1a5c0ff7..d2369b799c5 100644
--- a/arch/xtensa/platforms/iss/Makefile
+++ b/arch/xtensa/platforms/iss/Makefile
@@ -6,3 +6,4 @@
 
 obj-y			= console.o setup.o
 obj-$(CONFIG_NET)	+= network.o
+obj-$(CONFIG_BLK_DEV_SIMDISK) += simdisk.o
diff --git a/arch/xtensa/platforms/iss/simdisk.c b/arch/xtensa/platforms/iss/simdisk.c
new file mode 100644
index 00000000000..f58ffc3b68a
--- /dev/null
+++ b/arch/xtensa/platforms/iss/simdisk.c
@@ -0,0 +1,375 @@
+/*
+ * 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");