summaryrefslogtreecommitdiffstats
path: root/drivers/s390/char/tape_char.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/s390/char/tape_char.c
downloadop-kernel-dev-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip
op-kernel-dev-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/s390/char/tape_char.c')
-rw-r--r--drivers/s390/char/tape_char.c492
1 files changed, 492 insertions, 0 deletions
diff --git a/drivers/s390/char/tape_char.c b/drivers/s390/char/tape_char.c
new file mode 100644
index 0000000..86262a1
--- /dev/null
+++ b/drivers/s390/char/tape_char.c
@@ -0,0 +1,492 @@
+/*
+ * drivers/s390/char/tape_char.c
+ * character device frontend for tape device driver
+ *
+ * S390 and zSeries version
+ * Copyright (C) 2001,2002 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ * Author(s): Carsten Otte <cotte@de.ibm.com>
+ * Michael Holzheu <holzheu@de.ibm.com>
+ * Tuan Ngo-Anh <ngoanh@de.ibm.com>
+ * Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/proc_fs.h>
+#include <linux/mtio.h>
+
+#include <asm/uaccess.h>
+
+#define TAPE_DBF_AREA tape_core_dbf
+
+#include "tape.h"
+#include "tape_std.h"
+#include "tape_class.h"
+
+#define PRINTK_HEADER "TAPE_CHAR: "
+
+#define TAPECHAR_MAJOR 0 /* get dynamic major */
+
+/*
+ * file operation structure for tape character frontend
+ */
+static ssize_t tapechar_read(struct file *, char __user *, size_t, loff_t *);
+static ssize_t tapechar_write(struct file *, const char __user *, size_t, loff_t *);
+static int tapechar_open(struct inode *,struct file *);
+static int tapechar_release(struct inode *,struct file *);
+static int tapechar_ioctl(struct inode *, struct file *, unsigned int,
+ unsigned long);
+
+static struct file_operations tape_fops =
+{
+ .owner = THIS_MODULE,
+ .read = tapechar_read,
+ .write = tapechar_write,
+ .ioctl = tapechar_ioctl,
+ .open = tapechar_open,
+ .release = tapechar_release,
+};
+
+static int tapechar_major = TAPECHAR_MAJOR;
+
+/*
+ * This function is called for every new tapedevice
+ */
+int
+tapechar_setup_device(struct tape_device * device)
+{
+ char device_name[20];
+
+ sprintf(device_name, "ntibm%i", device->first_minor / 2);
+ device->nt = register_tape_dev(
+ &device->cdev->dev,
+ MKDEV(tapechar_major, device->first_minor),
+ &tape_fops,
+ device_name,
+ "non-rewinding"
+ );
+ device_name[0] = 'r';
+ device->rt = register_tape_dev(
+ &device->cdev->dev,
+ MKDEV(tapechar_major, device->first_minor + 1),
+ &tape_fops,
+ device_name,
+ "rewinding"
+ );
+
+ return 0;
+}
+
+void
+tapechar_cleanup_device(struct tape_device *device)
+{
+ unregister_tape_dev(device->rt);
+ device->rt = NULL;
+ unregister_tape_dev(device->nt);
+ device->nt = NULL;
+}
+
+/*
+ * Terminate write command (we write two TMs and skip backward over last)
+ * This ensures that the tape is always correctly terminated.
+ * When the user writes afterwards a new file, he will overwrite the
+ * second TM and therefore one TM will remain to separate the
+ * two files on the tape...
+ */
+static inline void
+tapechar_terminate_write(struct tape_device *device)
+{
+ if (tape_mtop(device, MTWEOF, 1) == 0 &&
+ tape_mtop(device, MTWEOF, 1) == 0)
+ tape_mtop(device, MTBSR, 1);
+}
+
+static inline int
+tapechar_check_idalbuffer(struct tape_device *device, size_t block_size)
+{
+ struct idal_buffer *new;
+
+ if (device->char_data.idal_buf != NULL &&
+ device->char_data.idal_buf->size == block_size)
+ return 0;
+
+ if (block_size > MAX_BLOCKSIZE) {
+ DBF_EVENT(3, "Invalid blocksize (%zd > %d)\n",
+ block_size, MAX_BLOCKSIZE);
+ PRINT_ERR("Invalid blocksize (%zd> %d)\n",
+ block_size, MAX_BLOCKSIZE);
+ return -EINVAL;
+ }
+
+ /* The current idal buffer is not correct. Allocate a new one. */
+ new = idal_buffer_alloc(block_size, 0);
+ if (new == NULL)
+ return -ENOMEM;
+
+ if (device->char_data.idal_buf != NULL)
+ idal_buffer_free(device->char_data.idal_buf);
+
+ device->char_data.idal_buf = new;
+
+ return 0;
+}
+
+/*
+ * Tape device read function
+ */
+ssize_t
+tapechar_read(struct file *filp, char __user *data, size_t count, loff_t *ppos)
+{
+ struct tape_device *device;
+ struct tape_request *request;
+ size_t block_size;
+ int rc;
+
+ DBF_EVENT(6, "TCHAR:read\n");
+ device = (struct tape_device *) filp->private_data;
+
+ /*
+ * If the tape isn't terminated yet, do it now. And since we then
+ * are at the end of the tape there wouldn't be anything to read
+ * anyways. So we return immediatly.
+ */
+ if(device->required_tapemarks) {
+ return tape_std_terminate_write(device);
+ }
+
+ /* Find out block size to use */
+ if (device->char_data.block_size != 0) {
+ if (count < device->char_data.block_size) {
+ DBF_EVENT(3, "TCHAR:read smaller than block "
+ "size was requested\n");
+ return -EINVAL;
+ }
+ block_size = device->char_data.block_size;
+ } else {
+ block_size = count;
+ }
+
+ rc = tapechar_check_idalbuffer(device, block_size);
+ if (rc)
+ return rc;
+
+#ifdef CONFIG_S390_TAPE_BLOCK
+ /* Changes position. */
+ device->blk_data.medium_changed = 1;
+#endif
+
+ DBF_EVENT(6, "TCHAR:nbytes: %lx\n", block_size);
+ /* Let the discipline build the ccw chain. */
+ request = device->discipline->read_block(device, block_size);
+ if (IS_ERR(request))
+ return PTR_ERR(request);
+ /* Execute it. */
+ rc = tape_do_io(device, request);
+ if (rc == 0) {
+ rc = block_size - request->rescnt;
+ DBF_EVENT(6, "TCHAR:rbytes: %x\n", rc);
+ filp->f_pos += rc;
+ /* Copy data from idal buffer to user space. */
+ if (idal_buffer_to_user(device->char_data.idal_buf,
+ data, rc) != 0)
+ rc = -EFAULT;
+ }
+ tape_free_request(request);
+ return rc;
+}
+
+/*
+ * Tape device write function
+ */
+ssize_t
+tapechar_write(struct file *filp, const char __user *data, size_t count, loff_t *ppos)
+{
+ struct tape_device *device;
+ struct tape_request *request;
+ size_t block_size;
+ size_t written;
+ int nblocks;
+ int i, rc;
+
+ DBF_EVENT(6, "TCHAR:write\n");
+ device = (struct tape_device *) filp->private_data;
+ /* Find out block size and number of blocks */
+ if (device->char_data.block_size != 0) {
+ if (count < device->char_data.block_size) {
+ DBF_EVENT(3, "TCHAR:write smaller than block "
+ "size was requested\n");
+ return -EINVAL;
+ }
+ block_size = device->char_data.block_size;
+ nblocks = count / block_size;
+ } else {
+ block_size = count;
+ nblocks = 1;
+ }
+
+ rc = tapechar_check_idalbuffer(device, block_size);
+ if (rc)
+ return rc;
+
+#ifdef CONFIG_S390_TAPE_BLOCK
+ /* Changes position. */
+ device->blk_data.medium_changed = 1;
+#endif
+
+ DBF_EVENT(6,"TCHAR:nbytes: %lx\n", block_size);
+ DBF_EVENT(6, "TCHAR:nblocks: %x\n", nblocks);
+ /* Let the discipline build the ccw chain. */
+ request = device->discipline->write_block(device, block_size);
+ if (IS_ERR(request))
+ return PTR_ERR(request);
+ rc = 0;
+ written = 0;
+ for (i = 0; i < nblocks; i++) {
+ /* Copy data from user space to idal buffer. */
+ if (idal_buffer_from_user(device->char_data.idal_buf,
+ data, block_size)) {
+ rc = -EFAULT;
+ break;
+ }
+ rc = tape_do_io(device, request);
+ if (rc)
+ break;
+ DBF_EVENT(6, "TCHAR:wbytes: %lx\n",
+ block_size - request->rescnt);
+ filp->f_pos += block_size - request->rescnt;
+ written += block_size - request->rescnt;
+ if (request->rescnt != 0)
+ break;
+ data += block_size;
+ }
+ tape_free_request(request);
+ if (rc == -ENOSPC) {
+ /*
+ * Ok, the device has no more space. It has NOT written
+ * the block.
+ */
+ if (device->discipline->process_eov)
+ device->discipline->process_eov(device);
+ if (written > 0)
+ rc = 0;
+
+ }
+
+ /*
+ * After doing a write we always need two tapemarks to correctly
+ * terminate the tape (one to terminate the file, the second to
+ * flag the end of recorded data.
+ * Since process_eov positions the tape in front of the written
+ * tapemark it doesn't hurt to write two marks again.
+ */
+ if (!rc)
+ device->required_tapemarks = 2;
+
+ return rc ? rc : written;
+}
+
+/*
+ * Character frontend tape device open function.
+ */
+int
+tapechar_open (struct inode *inode, struct file *filp)
+{
+ struct tape_device *device;
+ int minor, rc;
+
+ DBF_EVENT(6, "TCHAR:open: %i:%i\n",
+ imajor(filp->f_dentry->d_inode),
+ iminor(filp->f_dentry->d_inode));
+
+ if (imajor(filp->f_dentry->d_inode) != tapechar_major)
+ return -ENODEV;
+
+ minor = iminor(filp->f_dentry->d_inode);
+ device = tape_get_device(minor / TAPE_MINORS_PER_DEV);
+ if (IS_ERR(device)) {
+ DBF_EVENT(3, "TCHAR:open: tape_get_device() failed\n");
+ return PTR_ERR(device);
+ }
+
+
+ rc = tape_open(device);
+ if (rc == 0) {
+ filp->private_data = device;
+ return nonseekable_open(inode, filp);
+ }
+ tape_put_device(device);
+
+ return rc;
+}
+
+/*
+ * Character frontend tape device release function.
+ */
+
+int
+tapechar_release(struct inode *inode, struct file *filp)
+{
+ struct tape_device *device;
+
+ DBF_EVENT(6, "TCHAR:release: %x\n", iminor(inode));
+ device = (struct tape_device *) filp->private_data;
+
+ /*
+ * If this is the rewinding tape minor then rewind. In that case we
+ * write all required tapemarks. Otherwise only one to terminate the
+ * file.
+ */
+ if ((iminor(inode) & 1) != 0) {
+ if (device->required_tapemarks)
+ tape_std_terminate_write(device);
+ tape_mtop(device, MTREW, 1);
+ } else {
+ if (device->required_tapemarks > 1) {
+ if (tape_mtop(device, MTWEOF, 1) == 0)
+ device->required_tapemarks--;
+ }
+ }
+
+ if (device->char_data.idal_buf != NULL) {
+ idal_buffer_free(device->char_data.idal_buf);
+ device->char_data.idal_buf = NULL;
+ }
+ tape_release(device);
+ filp->private_data = tape_put_device(device);
+
+ return 0;
+}
+
+/*
+ * Tape device io controls.
+ */
+static int
+tapechar_ioctl(struct inode *inp, struct file *filp,
+ unsigned int no, unsigned long data)
+{
+ struct tape_device *device;
+ int rc;
+
+ DBF_EVENT(6, "TCHAR:ioct\n");
+
+ device = (struct tape_device *) filp->private_data;
+
+ if (no == MTIOCTOP) {
+ struct mtop op;
+
+ if (copy_from_user(&op, (char __user *) data, sizeof(op)) != 0)
+ return -EFAULT;
+ if (op.mt_count < 0)
+ return -EINVAL;
+
+ /*
+ * Operations that change tape position should write final
+ * tapemarks.
+ */
+ switch (op.mt_op) {
+ case MTFSF:
+ case MTBSF:
+ case MTFSR:
+ case MTBSR:
+ case MTREW:
+ case MTOFFL:
+ case MTEOM:
+ case MTRETEN:
+ case MTBSFM:
+ case MTFSFM:
+ case MTSEEK:
+#ifdef CONFIG_S390_TAPE_BLOCK
+ device->blk_data.medium_changed = 1;
+#endif
+ if (device->required_tapemarks)
+ tape_std_terminate_write(device);
+ default:
+ ;
+ }
+ rc = tape_mtop(device, op.mt_op, op.mt_count);
+
+ if (op.mt_op == MTWEOF && rc == 0) {
+ if (op.mt_count > device->required_tapemarks)
+ device->required_tapemarks = 0;
+ else
+ device->required_tapemarks -= op.mt_count;
+ }
+ return rc;
+ }
+ if (no == MTIOCPOS) {
+ /* MTIOCPOS: query the tape position. */
+ struct mtpos pos;
+
+ rc = tape_mtop(device, MTTELL, 1);
+ if (rc < 0)
+ return rc;
+ pos.mt_blkno = rc;
+ if (copy_to_user((char __user *) data, &pos, sizeof(pos)) != 0)
+ return -EFAULT;
+ return 0;
+ }
+ if (no == MTIOCGET) {
+ /* MTIOCGET: query the tape drive status. */
+ struct mtget get;
+
+ memset(&get, 0, sizeof(get));
+ get.mt_type = MT_ISUNKNOWN;
+ get.mt_resid = 0 /* device->devstat.rescnt */;
+ get.mt_dsreg = device->tape_state;
+ /* FIXME: mt_gstat, mt_erreg, mt_fileno */
+ get.mt_gstat = 0;
+ get.mt_erreg = 0;
+ get.mt_fileno = 0;
+ get.mt_gstat = device->tape_generic_status;
+
+ if (device->medium_state == MS_LOADED) {
+ rc = tape_mtop(device, MTTELL, 1);
+
+ if (rc < 0)
+ return rc;
+
+ if (rc == 0)
+ get.mt_gstat |= GMT_BOT(~0);
+
+ get.mt_blkno = rc;
+ }
+
+ if (copy_to_user((char __user *) data, &get, sizeof(get)) != 0)
+ return -EFAULT;
+
+ return 0;
+ }
+ /* Try the discipline ioctl function. */
+ if (device->discipline->ioctl_fn == NULL)
+ return -EINVAL;
+ return device->discipline->ioctl_fn(device, no, data);
+}
+
+/*
+ * Initialize character device frontend.
+ */
+int
+tapechar_init (void)
+{
+ dev_t dev;
+
+ if (alloc_chrdev_region(&dev, 0, 256, "tape") != 0)
+ return -1;
+
+ tapechar_major = MAJOR(dev);
+ PRINT_INFO("tape gets major %d for character devices\n", MAJOR(dev));
+
+ return 0;
+}
+
+/*
+ * cleanup
+ */
+void
+tapechar_exit(void)
+{
+ PRINT_INFO("tape releases major %d for character devices\n",
+ tapechar_major);
+ unregister_chrdev_region(MKDEV(tapechar_major, 0), 256);
+}
OpenPOWER on IntegriCloud