File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/s390/char/tape_std.c b/drivers/s390/char/tape_std.c
new file mode 100644
index 0000000..3478e19
--- /dev/null
+++ b/drivers/s390/char/tape_std.c
@@ -0,0 +1,750 @@
+/*
+ *    standard tape device functions for ibm tapes.
+ *
+ *  S390 and zSeries version
+ *    Copyright IBM Corp. 2001, 2002
+ *    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>
+ *		 Stefan Bader <shbader@de.ibm.com>
+ */
+
+#define KMSG_COMPONENT "tape"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/stddef.h>
+#include <linux/kernel.h>
+#include <linux/bio.h>
+#include <linux/timer.h>
+
+#include <asm/types.h>
+#include <asm/idals.h>
+#include <asm/ebcdic.h>
+#include <asm/tape390.h>
+
+#define TAPE_DBF_AREA	tape_core_dbf
+
+#include "tape.h"
+#include "tape_std.h"
+
+/*
+ * tape_std_assign
+ */
+static void
+tape_std_assign_timeout(unsigned long data)
+{
+	struct tape_request *	request;
+	struct tape_device *	device;
+	int rc;
+
+	request = (struct tape_request *) data;
+	device = request->device;
+	BUG_ON(!device);
+
+	DBF_EVENT(3, "%08x: Assignment timeout. Device busy.\n",
+			device->cdev_id);
+	rc = tape_cancel_io(device, request);
+	if(rc)
+		DBF_EVENT(3, "(%08x): Assign timeout: Cancel failed with rc = "
+			  "%i\n", device->cdev_id, rc);
+}
+
+int
+tape_std_assign(struct tape_device *device)
+{
+	int                  rc;
+	struct timer_list    timeout;
+	struct tape_request *request;
+
+	request = tape_alloc_request(2, 11);
+	if (IS_ERR(request))
+		return PTR_ERR(request);
+
+	request->op = TO_ASSIGN;
+	tape_ccw_cc(request->cpaddr, ASSIGN, 11, request->cpdata);
+	tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
+
+	/*
+	 * The assign command sometimes blocks if the device is assigned
+	 * to another host (actually this shouldn't happen but it does).
+	 * So we set up a timeout for this call.
+	 */
+	init_timer_on_stack(&timeout);
+	timeout.function = tape_std_assign_timeout;
+	timeout.data     = (unsigned long) request;
+	timeout.expires  = jiffies + 2 * HZ;
+	add_timer(&timeout);
+
+	rc = tape_do_io_interruptible(device, request);
+
+	del_timer_sync(&timeout);
+	destroy_timer_on_stack(&timeout);
+
+	if (rc != 0) {
+		DBF_EVENT(3, "%08x: assign failed - device might be busy\n",
+			device->cdev_id);
+	} else {
+		DBF_EVENT(3, "%08x: Tape assigned\n", device->cdev_id);
+	}
+	tape_free_request(request);
+	return rc;
+}
+
+/*
+ * tape_std_unassign
+ */
+int
+tape_std_unassign (struct tape_device *device)
+{
+	int                  rc;
+	struct tape_request *request;
+
+	if (device->tape_state == TS_NOT_OPER) {
+		DBF_EVENT(3, "(%08x): Can't unassign device\n",
+			device->cdev_id);
+		return -EIO;
+	}
+
+	request = tape_alloc_request(2, 11);
+	if (IS_ERR(request))
+		return PTR_ERR(request);
+
+	request->op = TO_UNASSIGN;
+	tape_ccw_cc(request->cpaddr, UNASSIGN, 11, request->cpdata);
+	tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
+
+	if ((rc = tape_do_io(device, request)) != 0) {
+		DBF_EVENT(3, "%08x: Unassign failed\n", device->cdev_id);
+	} else {
+		DBF_EVENT(3, "%08x: Tape unassigned\n", device->cdev_id);
+	}
+	tape_free_request(request);
+	return rc;
+}
+
+/*
+ * TAPE390_DISPLAY: Show a string on the tape display.
+ */
+int
+tape_std_display(struct tape_device *device, struct display_struct *disp)
+{
+	struct tape_request *request;
+	int rc;
+
+	request = tape_alloc_request(2, 17);
+	if (IS_ERR(request)) {
+		DBF_EVENT(3, "TAPE: load display failed\n");
+		return PTR_ERR(request);
+	}
+	request->op = TO_DIS;
+
+	*(unsigned char *) request->cpdata = disp->cntrl;
+	DBF_EVENT(5, "TAPE: display cntrl=%04x\n", disp->cntrl);
+	memcpy(((unsigned char *) request->cpdata) + 1, disp->message1, 8);
+	memcpy(((unsigned char *) request->cpdata) + 9, disp->message2, 8);
+	ASCEBC(((unsigned char*) request->cpdata) + 1, 16);
+
+	tape_ccw_cc(request->cpaddr, LOAD_DISPLAY, 17, request->cpdata);
+	tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
+
+	rc = tape_do_io_interruptible(device, request);
+	tape_free_request(request);
+	return rc;
+}
+
+/*
+ * Read block id.
+ */
+int
+tape_std_read_block_id(struct tape_device *device, __u64 *id)
+{
+	struct tape_request *request;
+	int rc;
+
+	request = tape_alloc_request(3, 8);
+	if (IS_ERR(request))
+		return PTR_ERR(request);
+	request->op = TO_RBI;
+	/* setup ccws */
+	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
+	tape_ccw_cc(request->cpaddr + 1, READ_BLOCK_ID, 8, request->cpdata);
+	tape_ccw_end(request->cpaddr + 2, NOP, 0, NULL);
+	/* execute it */
+	rc = tape_do_io(device, request);
+	if (rc == 0)
+		/* Get result from read buffer. */
+		*id = *(__u64 *) request->cpdata;
+	tape_free_request(request);
+	return rc;
+}
+
+int
+tape_std_terminate_write(struct tape_device *device)
+{
+	int rc;
+
+	if(device->required_tapemarks == 0)
+		return 0;
+
+	DBF_LH(5, "tape%d: terminate write %dxEOF\n", device->first_minor,
+		device->required_tapemarks);
+
+	rc = tape_mtop(device, MTWEOF, device->required_tapemarks);
+	if (rc)
+		return rc;
+
+	device->required_tapemarks = 0;
+	return tape_mtop(device, MTBSR, 1);
+}
+
+/*
+ * MTLOAD: Loads the tape.
+ * The default implementation just wait until the tape medium state changes
+ * to MS_LOADED.
+ */
+int
+tape_std_mtload(struct tape_device *device, int count)
+{
+	return wait_event_interruptible(device->state_change_wq,
+		(device->medium_state == MS_LOADED));
+}
+
+/*
+ * MTSETBLK: Set block size.
+ */
+int
+tape_std_mtsetblk(struct tape_device *device, int count)
+{
+	struct idal_buffer *new;
+
+	DBF_LH(6, "tape_std_mtsetblk(%d)\n", count);
+	if (count <= 0) {
+		/*
+		 * Just set block_size to 0. tapechar_read/tapechar_write
+		 * will realloc the idal buffer if a bigger one than the
+		 * current is needed.
+		 */
+		device->char_data.block_size = 0;
+		return 0;
+	}
+	if (device->char_data.idal_buf != NULL &&
+	    device->char_data.idal_buf->size == count)
+		/* We already have a idal buffer of that size. */
+		return 0;
+
+	if (count > MAX_BLOCKSIZE) {
+		DBF_EVENT(3, "Invalid block size (%d > %d) given.\n",
+			count, MAX_BLOCKSIZE);
+		return -EINVAL;
+	}
+
+	/* Allocate a new idal buffer. */
+	new = idal_buffer_alloc(count, 0);
+	if (IS_ERR(new))
+		return -ENOMEM;
+	if (device->char_data.idal_buf != NULL)
+		idal_buffer_free(device->char_data.idal_buf);
+	device->char_data.idal_buf = new;
+	device->char_data.block_size = count;
+
+	DBF_LH(6, "new blocksize is %d\n", device->char_data.block_size);
+
+	return 0;
+}
+
+/*
+ * MTRESET: Set block size to 0.
+ */
+int
+tape_std_mtreset(struct tape_device *device, int count)
+{
+	DBF_EVENT(6, "TCHAR:devreset:\n");
+	device->char_data.block_size = 0;
+	return 0;
+}
+
+/*
+ * MTFSF: Forward space over 'count' file marks. The tape is positioned
+ * at the EOT (End of Tape) side of the file mark.
+ */
+int
+tape_std_mtfsf(struct tape_device *device, int mt_count)
+{
+	struct tape_request *request;
+	struct ccw1 *ccw;
+
+	request = tape_alloc_request(mt_count + 2, 0);
+	if (IS_ERR(request))
+		return PTR_ERR(request);
+	request->op = TO_FSF;
+	/* setup ccws */
+	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
+			  device->modeset_byte);
+	ccw = tape_ccw_repeat(ccw, FORSPACEFILE, mt_count);
+	ccw = tape_ccw_end(ccw, NOP, 0, NULL);
+
+	/* execute it */
+	return tape_do_io_free(device, request);
+}
+
+/*
+ * MTFSR: Forward space over 'count' tape blocks (blocksize is set
+ * via MTSETBLK.
+ */
+int
+tape_std_mtfsr(struct tape_device *device, int mt_count)
+{
+	struct tape_request *request;
+	struct ccw1 *ccw;
+	int rc;
+
+	request = tape_alloc_request(mt_count + 2, 0);
+	if (IS_ERR(request))
+		return PTR_ERR(request);
+	request->op = TO_FSB;
+	/* setup ccws */
+	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
+			  device->modeset_byte);
+	ccw = tape_ccw_repeat(ccw, FORSPACEBLOCK, mt_count);
+	ccw = tape_ccw_end(ccw, NOP, 0, NULL);
+
+	/* execute it */
+	rc = tape_do_io(device, request);
+	if (rc == 0 && request->rescnt > 0) {
+		DBF_LH(3, "FSR over tapemark\n");
+		rc = 1;
+	}
+	tape_free_request(request);
+
+	return rc;
+}
+
+/*
+ * MTBSR: Backward space over 'count' tape blocks.
+ * (blocksize is set via MTSETBLK.
+ */
+int
+tape_std_mtbsr(struct tape_device *device, int mt_count)
+{
+	struct tape_request *request;
+	struct ccw1 *ccw;
+	int rc;
+
+	request = tape_alloc_request(mt_count + 2, 0);
+	if (IS_ERR(request))
+		return PTR_ERR(request);
+	request->op = TO_BSB;
+	/* setup ccws */
+	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
+			  device->modeset_byte);
+	ccw = tape_ccw_repeat(ccw, BACKSPACEBLOCK, mt_count);
+	ccw = tape_ccw_end(ccw, NOP, 0, NULL);
+
+	/* execute it */
+	rc = tape_do_io(device, request);
+	if (rc == 0 && request->rescnt > 0) {
+		DBF_LH(3, "BSR over tapemark\n");
+		rc = 1;
+	}
+	tape_free_request(request);
+
+	return rc;
+}
+
+/*
+ * MTWEOF: Write 'count' file marks at the current position.
+ */
+int
+tape_std_mtweof(struct tape_device *device, int mt_count)
+{
+	struct tape_request *request;
+	struct ccw1 *ccw;
+
+	request = tape_alloc_request(mt_count + 2, 0);
+	if (IS_ERR(request))
+		return PTR_ERR(request);
+	request->op = TO_WTM;
+	/* setup ccws */
+	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
+			  device->modeset_byte);
+	ccw = tape_ccw_repeat(ccw, WRITETAPEMARK, mt_count);
+	ccw = tape_ccw_end(ccw, NOP, 0, NULL);
+
+	/* execute it */
+	return tape_do_io_free(device, request);
+}
+
+/*
+ * MTBSFM: Backward space over 'count' file marks.
+ * The tape is positioned at the BOT (Begin Of Tape) side of the
+ * last skipped file mark.
+ */
+int
+tape_std_mtbsfm(struct tape_device *device, int mt_count)
+{
+	struct tape_request *request;
+	struct ccw1 *ccw;
+
+	request = tape_alloc_request(mt_count + 2, 0);
+	if (IS_ERR(request))
+		return PTR_ERR(request);
+	request->op = TO_BSF;
+	/* setup ccws */
+	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
+			  device->modeset_byte);
+	ccw = tape_ccw_repeat(ccw, BACKSPACEFILE, mt_count);
+	ccw = tape_ccw_end(ccw, NOP, 0, NULL);
+
+	/* execute it */
+	return tape_do_io_free(device, request);
+}
+
+/*
+ * MTBSF: Backward space over 'count' file marks. The tape is positioned at
+ * the EOT (End of Tape) side of the last skipped file mark.
+ */
+int
+tape_std_mtbsf(struct tape_device *device, int mt_count)
+{
+	struct tape_request *request;
+	struct ccw1 *ccw;
+	int rc;
+
+	request = tape_alloc_request(mt_count + 2, 0);
+	if (IS_ERR(request))
+		return PTR_ERR(request);
+	request->op = TO_BSF;
+	/* setup ccws */
+	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
+			  device->modeset_byte);
+	ccw = tape_ccw_repeat(ccw, BACKSPACEFILE, mt_count);
+	ccw = tape_ccw_end(ccw, NOP, 0, NULL);
+	/* execute it */
+	rc = tape_do_io_free(device, request);
+	if (rc == 0) {
+		rc = tape_mtop(device, MTFSR, 1);
+		if (rc > 0)
+			rc = 0;
+	}
+	return rc;
+}
+
+/*
+ * MTFSFM: Forward space over 'count' file marks.
+ * The tape is positioned at the BOT (Begin Of Tape) side
+ * of the last skipped file mark.
+ */
+int
+tape_std_mtfsfm(struct tape_device *device, int mt_count)
+{
+	struct tape_request *request;
+	struct ccw1 *ccw;
+	int rc;
+
+	request = tape_alloc_request(mt_count + 2, 0);
+	if (IS_ERR(request))
+		return PTR_ERR(request);
+	request->op = TO_FSF;
+	/* setup ccws */
+	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
+			  device->modeset_byte);
+	ccw = tape_ccw_repeat(ccw, FORSPACEFILE, mt_count);
+	ccw = tape_ccw_end(ccw, NOP, 0, NULL);
+	/* execute it */
+	rc = tape_do_io_free(device, request);
+	if (rc == 0) {
+		rc = tape_mtop(device, MTBSR, 1);
+		if (rc > 0)
+			rc = 0;
+	}
+
+	return rc;
+}
+
+/*
+ * MTREW: Rewind the tape.
+ */
+int
+tape_std_mtrew(struct tape_device *device, int mt_count)
+{
+	struct tape_request *request;
+
+	request = tape_alloc_request(3, 0);
+	if (IS_ERR(request))
+		return PTR_ERR(request);
+	request->op = TO_REW;
+	/* setup ccws */
+	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
+		    device->modeset_byte);
+	tape_ccw_cc(request->cpaddr + 1, REWIND, 0, NULL);
+	tape_ccw_end(request->cpaddr + 2, NOP, 0, NULL);
+
+	/* execute it */
+	return tape_do_io_free(device, request);
+}
+
+/*
+ * MTOFFL: Rewind the tape and put the drive off-line.
+ * Implement 'rewind unload'
+ */
+int
+tape_std_mtoffl(struct tape_device *device, int mt_count)
+{
+	struct tape_request *request;
+
+	request = tape_alloc_request(3, 0);
+	if (IS_ERR(request))
+		return PTR_ERR(request);
+	request->op = TO_RUN;
+	/* setup ccws */
+	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
+	tape_ccw_cc(request->cpaddr + 1, REWIND_UNLOAD, 0, NULL);
+	tape_ccw_end(request->cpaddr + 2, NOP, 0, NULL);
+
+	/* execute it */
+	return tape_do_io_free(device, request);
+}
+
+/*
+ * MTNOP: 'No operation'.
+ */
+int
+tape_std_mtnop(struct tape_device *device, int mt_count)
+{
+	struct tape_request *request;
+
+	request = tape_alloc_request(2, 0);
+	if (IS_ERR(request))
+		return PTR_ERR(request);
+	request->op = TO_NOP;
+	/* setup ccws */
+	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
+	tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
+	/* execute it */
+	return tape_do_io_free(device, request);
+}
+
+/*
+ * MTEOM: positions at the end of the portion of the tape already used
+ * for recordind data. MTEOM positions after the last file mark, ready for
+ * appending another file.
+ */
+int
+tape_std_mteom(struct tape_device *device, int mt_count)
+{
+	int rc;
+
+	/*
+	 * Seek from the beginning of tape (rewind).
+	 */
+	if ((rc = tape_mtop(device, MTREW, 1)) < 0)
+		return rc;
+
+	/*
+	 * The logical end of volume is given by two sewuential tapemarks.
+	 * Look for this by skipping to the next file (over one tapemark)
+	 * and then test for another one (fsr returns 1 if a tapemark was
+	 * encountered).
+	 */
+	do {
+		if ((rc = tape_mtop(device, MTFSF, 1)) < 0)
+			return rc;
+		if ((rc = tape_mtop(device, MTFSR, 1)) < 0)
+			return rc;
+	} while (rc == 0);
+
+	return tape_mtop(device, MTBSR, 1);
+}
+
+/*
+ * MTRETEN: Retension the tape, i.e. forward space to end of tape and rewind.
+ */
+int
+tape_std_mtreten(struct tape_device *device, int mt_count)
+{
+	struct tape_request *request;
+
+	request = tape_alloc_request(4, 0);
+	if (IS_ERR(request))
+		return PTR_ERR(request);
+	request->op = TO_FSF;
+	/* setup ccws */
+	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
+	tape_ccw_cc(request->cpaddr + 1,FORSPACEFILE, 0, NULL);
+	tape_ccw_cc(request->cpaddr + 2, NOP, 0, NULL);
+	tape_ccw_end(request->cpaddr + 3, CCW_CMD_TIC, 0, request->cpaddr);
+	/* execute it, MTRETEN rc gets ignored */
+	tape_do_io_interruptible(device, request);
+	tape_free_request(request);
+	return tape_mtop(device, MTREW, 1);
+}
+
+/*
+ * MTERASE: erases the tape.
+ */
+int
+tape_std_mterase(struct tape_device *device, int mt_count)
+{
+	struct tape_request *request;
+
+	request = tape_alloc_request(6, 0);
+	if (IS_ERR(request))
+		return PTR_ERR(request);
+	request->op = TO_DSE;
+	/* setup ccws */
+	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
+	tape_ccw_cc(request->cpaddr + 1, REWIND, 0, NULL);
+	tape_ccw_cc(request->cpaddr + 2, ERASE_GAP, 0, NULL);
+	tape_ccw_cc(request->cpaddr + 3, DATA_SEC_ERASE, 0, NULL);
+	tape_ccw_cc(request->cpaddr + 4, REWIND, 0, NULL);
+	tape_ccw_end(request->cpaddr + 5, NOP, 0, NULL);
+
+	/* execute it */
+	return tape_do_io_free(device, request);
+}
+
+/*
+ * MTUNLOAD: Rewind the tape and unload it.
+ */
+int
+tape_std_mtunload(struct tape_device *device, int mt_count)
+{
+	return tape_mtop(device, MTOFFL, mt_count);
+}
+
+/*
+ * MTCOMPRESSION: used to enable compression.
+ * Sets the IDRC on/off.
+ */
+int
+tape_std_mtcompression(struct tape_device *device, int mt_count)
+{
+	struct tape_request *request;
+
+	if (mt_count < 0 || mt_count > 1) {
+		DBF_EXCEPTION(6, "xcom parm\n");
+		return -EINVAL;
+	}
+	request = tape_alloc_request(2, 0);
+	if (IS_ERR(request))
+		return PTR_ERR(request);
+	request->op = TO_NOP;
+	/* setup ccws */
+	if (mt_count == 0)
+		*device->modeset_byte &= ~0x08;
+	else
+		*device->modeset_byte |= 0x08;
+	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
+	tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
+	/* execute it */
+	return tape_do_io_free(device, request);
+}
+
+/*
+ * Read Block
+ */
+struct tape_request *
+tape_std_read_block(struct tape_device *device, size_t count)
+{
+	struct tape_request *request;
+
+	/*
+	 * We have to alloc 4 ccws in order to be able to transform request
+	 * into a read backward request in error case.
+	 */
+	request = tape_alloc_request(4, 0);
+	if (IS_ERR(request)) {
+		DBF_EXCEPTION(6, "xrbl fail");
+		return request;
+	}
+	request->op = TO_RFO;
+	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
+	tape_ccw_end_idal(request->cpaddr + 1, READ_FORWARD,
+			  device->char_data.idal_buf);
+	DBF_EVENT(6, "xrbl ccwg\n");
+	return request;
+}
+
+/*
+ * Read Block backward transformation function.
+ */
+void
+tape_std_read_backward(struct tape_device *device, struct tape_request *request)
+{
+	/*
+	 * We have allocated 4 ccws in tape_std_read, so we can now
+	 * transform the request to a read backward, followed by a
+	 * forward space block.
+	 */
+	request->op = TO_RBA;
+	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
+	tape_ccw_cc_idal(request->cpaddr + 1, READ_BACKWARD,
+			 device->char_data.idal_buf);
+	tape_ccw_cc(request->cpaddr + 2, FORSPACEBLOCK, 0, NULL);
+	tape_ccw_end(request->cpaddr + 3, NOP, 0, NULL);
+	DBF_EVENT(6, "xrop ccwg");}
+
+/*
+ * Write Block
+ */
+struct tape_request *
+tape_std_write_block(struct tape_device *device, size_t count)
+{
+	struct tape_request *request;
+
+	request = tape_alloc_request(2, 0);
+	if (IS_ERR(request)) {
+		DBF_EXCEPTION(6, "xwbl fail\n");
+		return request;
+	}
+	request->op = TO_WRI;
+	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
+	tape_ccw_end_idal(request->cpaddr + 1, WRITE_CMD,
+			  device->char_data.idal_buf);
+	DBF_EVENT(6, "xwbl ccwg\n");
+	return request;
+}
+
+/*
+ * This routine is called by frontend after an ENOSP on write
+ */
+void
+tape_std_process_eov(struct tape_device *device)
+{
+	/*
+	 * End of volume: We have to backspace the last written record, then
+	 * we TRY to write a tapemark and then backspace over the written TM
+	 */
+	if (tape_mtop(device, MTBSR, 1) == 0 &&
+	    tape_mtop(device, MTWEOF, 1) == 0) {
+		tape_mtop(device, MTBSR, 1);
+	}
+}
+
+EXPORT_SYMBOL(tape_std_assign);
+EXPORT_SYMBOL(tape_std_unassign);
+EXPORT_SYMBOL(tape_std_display);
+EXPORT_SYMBOL(tape_std_read_block_id);
+EXPORT_SYMBOL(tape_std_mtload);
+EXPORT_SYMBOL(tape_std_mtsetblk);
+EXPORT_SYMBOL(tape_std_mtreset);
+EXPORT_SYMBOL(tape_std_mtfsf);
+EXPORT_SYMBOL(tape_std_mtfsr);
+EXPORT_SYMBOL(tape_std_mtbsr);
+EXPORT_SYMBOL(tape_std_mtweof);
+EXPORT_SYMBOL(tape_std_mtbsfm);
+EXPORT_SYMBOL(tape_std_mtbsf);
+EXPORT_SYMBOL(tape_std_mtfsfm);
+EXPORT_SYMBOL(tape_std_mtrew);
+EXPORT_SYMBOL(tape_std_mtoffl);
+EXPORT_SYMBOL(tape_std_mtnop);
+EXPORT_SYMBOL(tape_std_mteom);
+EXPORT_SYMBOL(tape_std_mtreten);
+EXPORT_SYMBOL(tape_std_mterase);
+EXPORT_SYMBOL(tape_std_mtunload);
+EXPORT_SYMBOL(tape_std_mtcompression);
+EXPORT_SYMBOL(tape_std_read_block);
+EXPORT_SYMBOL(tape_std_read_backward);
+EXPORT_SYMBOL(tape_std_write_block);
+EXPORT_SYMBOL(tape_std_process_eov);