cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
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tape_std.c (18413B)


      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 *    standard tape device functions for ibm tapes.
      4 *
      5 *  S390 and zSeries version
      6 *    Copyright IBM Corp. 2001, 2002
      7 *    Author(s): Carsten Otte <cotte@de.ibm.com>
      8 *		 Michael Holzheu <holzheu@de.ibm.com>
      9 *		 Tuan Ngo-Anh <ngoanh@de.ibm.com>
     10 *		 Martin Schwidefsky <schwidefsky@de.ibm.com>
     11 *		 Stefan Bader <shbader@de.ibm.com>
     12 */
     13
     14#define KMSG_COMPONENT "tape"
     15#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
     16
     17#include <linux/stddef.h>
     18#include <linux/kernel.h>
     19#include <linux/bio.h>
     20#include <linux/timer.h>
     21
     22#include <asm/types.h>
     23#include <asm/idals.h>
     24#include <asm/ebcdic.h>
     25#include <asm/tape390.h>
     26
     27#define TAPE_DBF_AREA	tape_core_dbf
     28
     29#include "tape.h"
     30#include "tape_std.h"
     31
     32/*
     33 * tape_std_assign
     34 */
     35static void
     36tape_std_assign_timeout(struct timer_list *t)
     37{
     38	struct tape_request *	request = from_timer(request, t, timer);
     39	struct tape_device *	device = request->device;
     40	int rc;
     41
     42	BUG_ON(!device);
     43
     44	DBF_EVENT(3, "%08x: Assignment timeout. Device busy.\n",
     45			device->cdev_id);
     46	rc = tape_cancel_io(device, request);
     47	if(rc)
     48		DBF_EVENT(3, "(%08x): Assign timeout: Cancel failed with rc = "
     49			  "%i\n", device->cdev_id, rc);
     50}
     51
     52int
     53tape_std_assign(struct tape_device *device)
     54{
     55	int                  rc;
     56	struct tape_request *request;
     57
     58	request = tape_alloc_request(2, 11);
     59	if (IS_ERR(request))
     60		return PTR_ERR(request);
     61
     62	request->op = TO_ASSIGN;
     63	tape_ccw_cc(request->cpaddr, ASSIGN, 11, request->cpdata);
     64	tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
     65
     66	/*
     67	 * The assign command sometimes blocks if the device is assigned
     68	 * to another host (actually this shouldn't happen but it does).
     69	 * So we set up a timeout for this call.
     70	 */
     71	timer_setup(&request->timer, tape_std_assign_timeout, 0);
     72	mod_timer(&request->timer, jiffies + msecs_to_jiffies(2000));
     73
     74	rc = tape_do_io_interruptible(device, request);
     75
     76	del_timer_sync(&request->timer);
     77
     78	if (rc != 0) {
     79		DBF_EVENT(3, "%08x: assign failed - device might be busy\n",
     80			device->cdev_id);
     81	} else {
     82		DBF_EVENT(3, "%08x: Tape assigned\n", device->cdev_id);
     83	}
     84	tape_free_request(request);
     85	return rc;
     86}
     87
     88/*
     89 * tape_std_unassign
     90 */
     91int
     92tape_std_unassign (struct tape_device *device)
     93{
     94	int                  rc;
     95	struct tape_request *request;
     96
     97	if (device->tape_state == TS_NOT_OPER) {
     98		DBF_EVENT(3, "(%08x): Can't unassign device\n",
     99			device->cdev_id);
    100		return -EIO;
    101	}
    102
    103	request = tape_alloc_request(2, 11);
    104	if (IS_ERR(request))
    105		return PTR_ERR(request);
    106
    107	request->op = TO_UNASSIGN;
    108	tape_ccw_cc(request->cpaddr, UNASSIGN, 11, request->cpdata);
    109	tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
    110
    111	if ((rc = tape_do_io(device, request)) != 0) {
    112		DBF_EVENT(3, "%08x: Unassign failed\n", device->cdev_id);
    113	} else {
    114		DBF_EVENT(3, "%08x: Tape unassigned\n", device->cdev_id);
    115	}
    116	tape_free_request(request);
    117	return rc;
    118}
    119
    120/*
    121 * TAPE390_DISPLAY: Show a string on the tape display.
    122 */
    123int
    124tape_std_display(struct tape_device *device, struct display_struct *disp)
    125{
    126	struct tape_request *request;
    127	int rc;
    128
    129	request = tape_alloc_request(2, 17);
    130	if (IS_ERR(request)) {
    131		DBF_EVENT(3, "TAPE: load display failed\n");
    132		return PTR_ERR(request);
    133	}
    134	request->op = TO_DIS;
    135
    136	*(unsigned char *) request->cpdata = disp->cntrl;
    137	DBF_EVENT(5, "TAPE: display cntrl=%04x\n", disp->cntrl);
    138	memcpy(((unsigned char *) request->cpdata) + 1, disp->message1, 8);
    139	memcpy(((unsigned char *) request->cpdata) + 9, disp->message2, 8);
    140	ASCEBC(((unsigned char*) request->cpdata) + 1, 16);
    141
    142	tape_ccw_cc(request->cpaddr, LOAD_DISPLAY, 17, request->cpdata);
    143	tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
    144
    145	rc = tape_do_io_interruptible(device, request);
    146	tape_free_request(request);
    147	return rc;
    148}
    149
    150/*
    151 * Read block id.
    152 */
    153int
    154tape_std_read_block_id(struct tape_device *device, __u64 *id)
    155{
    156	struct tape_request *request;
    157	int rc;
    158
    159	request = tape_alloc_request(3, 8);
    160	if (IS_ERR(request))
    161		return PTR_ERR(request);
    162	request->op = TO_RBI;
    163	/* setup ccws */
    164	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
    165	tape_ccw_cc(request->cpaddr + 1, READ_BLOCK_ID, 8, request->cpdata);
    166	tape_ccw_end(request->cpaddr + 2, NOP, 0, NULL);
    167	/* execute it */
    168	rc = tape_do_io(device, request);
    169	if (rc == 0)
    170		/* Get result from read buffer. */
    171		*id = *(__u64 *) request->cpdata;
    172	tape_free_request(request);
    173	return rc;
    174}
    175
    176int
    177tape_std_terminate_write(struct tape_device *device)
    178{
    179	int rc;
    180
    181	if(device->required_tapemarks == 0)
    182		return 0;
    183
    184	DBF_LH(5, "tape%d: terminate write %dxEOF\n", device->first_minor,
    185		device->required_tapemarks);
    186
    187	rc = tape_mtop(device, MTWEOF, device->required_tapemarks);
    188	if (rc)
    189		return rc;
    190
    191	device->required_tapemarks = 0;
    192	return tape_mtop(device, MTBSR, 1);
    193}
    194
    195/*
    196 * MTLOAD: Loads the tape.
    197 * The default implementation just wait until the tape medium state changes
    198 * to MS_LOADED.
    199 */
    200int
    201tape_std_mtload(struct tape_device *device, int count)
    202{
    203	return wait_event_interruptible(device->state_change_wq,
    204		(device->medium_state == MS_LOADED));
    205}
    206
    207/*
    208 * MTSETBLK: Set block size.
    209 */
    210int
    211tape_std_mtsetblk(struct tape_device *device, int count)
    212{
    213	struct idal_buffer *new;
    214
    215	DBF_LH(6, "tape_std_mtsetblk(%d)\n", count);
    216	if (count <= 0) {
    217		/*
    218		 * Just set block_size to 0. tapechar_read/tapechar_write
    219		 * will realloc the idal buffer if a bigger one than the
    220		 * current is needed.
    221		 */
    222		device->char_data.block_size = 0;
    223		return 0;
    224	}
    225	if (device->char_data.idal_buf != NULL &&
    226	    device->char_data.idal_buf->size == count)
    227		/* We already have a idal buffer of that size. */
    228		return 0;
    229
    230	if (count > MAX_BLOCKSIZE) {
    231		DBF_EVENT(3, "Invalid block size (%d > %d) given.\n",
    232			count, MAX_BLOCKSIZE);
    233		return -EINVAL;
    234	}
    235
    236	/* Allocate a new idal buffer. */
    237	new = idal_buffer_alloc(count, 0);
    238	if (IS_ERR(new))
    239		return -ENOMEM;
    240	if (device->char_data.idal_buf != NULL)
    241		idal_buffer_free(device->char_data.idal_buf);
    242	device->char_data.idal_buf = new;
    243	device->char_data.block_size = count;
    244
    245	DBF_LH(6, "new blocksize is %d\n", device->char_data.block_size);
    246
    247	return 0;
    248}
    249
    250/*
    251 * MTRESET: Set block size to 0.
    252 */
    253int
    254tape_std_mtreset(struct tape_device *device, int count)
    255{
    256	DBF_EVENT(6, "TCHAR:devreset:\n");
    257	device->char_data.block_size = 0;
    258	return 0;
    259}
    260
    261/*
    262 * MTFSF: Forward space over 'count' file marks. The tape is positioned
    263 * at the EOT (End of Tape) side of the file mark.
    264 */
    265int
    266tape_std_mtfsf(struct tape_device *device, int mt_count)
    267{
    268	struct tape_request *request;
    269	struct ccw1 *ccw;
    270
    271	request = tape_alloc_request(mt_count + 2, 0);
    272	if (IS_ERR(request))
    273		return PTR_ERR(request);
    274	request->op = TO_FSF;
    275	/* setup ccws */
    276	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
    277			  device->modeset_byte);
    278	ccw = tape_ccw_repeat(ccw, FORSPACEFILE, mt_count);
    279	ccw = tape_ccw_end(ccw, NOP, 0, NULL);
    280
    281	/* execute it */
    282	return tape_do_io_free(device, request);
    283}
    284
    285/*
    286 * MTFSR: Forward space over 'count' tape blocks (blocksize is set
    287 * via MTSETBLK.
    288 */
    289int
    290tape_std_mtfsr(struct tape_device *device, int mt_count)
    291{
    292	struct tape_request *request;
    293	struct ccw1 *ccw;
    294	int rc;
    295
    296	request = tape_alloc_request(mt_count + 2, 0);
    297	if (IS_ERR(request))
    298		return PTR_ERR(request);
    299	request->op = TO_FSB;
    300	/* setup ccws */
    301	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
    302			  device->modeset_byte);
    303	ccw = tape_ccw_repeat(ccw, FORSPACEBLOCK, mt_count);
    304	ccw = tape_ccw_end(ccw, NOP, 0, NULL);
    305
    306	/* execute it */
    307	rc = tape_do_io(device, request);
    308	if (rc == 0 && request->rescnt > 0) {
    309		DBF_LH(3, "FSR over tapemark\n");
    310		rc = 1;
    311	}
    312	tape_free_request(request);
    313
    314	return rc;
    315}
    316
    317/*
    318 * MTBSR: Backward space over 'count' tape blocks.
    319 * (blocksize is set via MTSETBLK.
    320 */
    321int
    322tape_std_mtbsr(struct tape_device *device, int mt_count)
    323{
    324	struct tape_request *request;
    325	struct ccw1 *ccw;
    326	int rc;
    327
    328	request = tape_alloc_request(mt_count + 2, 0);
    329	if (IS_ERR(request))
    330		return PTR_ERR(request);
    331	request->op = TO_BSB;
    332	/* setup ccws */
    333	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
    334			  device->modeset_byte);
    335	ccw = tape_ccw_repeat(ccw, BACKSPACEBLOCK, mt_count);
    336	ccw = tape_ccw_end(ccw, NOP, 0, NULL);
    337
    338	/* execute it */
    339	rc = tape_do_io(device, request);
    340	if (rc == 0 && request->rescnt > 0) {
    341		DBF_LH(3, "BSR over tapemark\n");
    342		rc = 1;
    343	}
    344	tape_free_request(request);
    345
    346	return rc;
    347}
    348
    349/*
    350 * MTWEOF: Write 'count' file marks at the current position.
    351 */
    352int
    353tape_std_mtweof(struct tape_device *device, int mt_count)
    354{
    355	struct tape_request *request;
    356	struct ccw1 *ccw;
    357
    358	request = tape_alloc_request(mt_count + 2, 0);
    359	if (IS_ERR(request))
    360		return PTR_ERR(request);
    361	request->op = TO_WTM;
    362	/* setup ccws */
    363	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
    364			  device->modeset_byte);
    365	ccw = tape_ccw_repeat(ccw, WRITETAPEMARK, mt_count);
    366	ccw = tape_ccw_end(ccw, NOP, 0, NULL);
    367
    368	/* execute it */
    369	return tape_do_io_free(device, request);
    370}
    371
    372/*
    373 * MTBSFM: Backward space over 'count' file marks.
    374 * The tape is positioned at the BOT (Begin Of Tape) side of the
    375 * last skipped file mark.
    376 */
    377int
    378tape_std_mtbsfm(struct tape_device *device, int mt_count)
    379{
    380	struct tape_request *request;
    381	struct ccw1 *ccw;
    382
    383	request = tape_alloc_request(mt_count + 2, 0);
    384	if (IS_ERR(request))
    385		return PTR_ERR(request);
    386	request->op = TO_BSF;
    387	/* setup ccws */
    388	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
    389			  device->modeset_byte);
    390	ccw = tape_ccw_repeat(ccw, BACKSPACEFILE, mt_count);
    391	ccw = tape_ccw_end(ccw, NOP, 0, NULL);
    392
    393	/* execute it */
    394	return tape_do_io_free(device, request);
    395}
    396
    397/*
    398 * MTBSF: Backward space over 'count' file marks. The tape is positioned at
    399 * the EOT (End of Tape) side of the last skipped file mark.
    400 */
    401int
    402tape_std_mtbsf(struct tape_device *device, int mt_count)
    403{
    404	struct tape_request *request;
    405	struct ccw1 *ccw;
    406	int rc;
    407
    408	request = tape_alloc_request(mt_count + 2, 0);
    409	if (IS_ERR(request))
    410		return PTR_ERR(request);
    411	request->op = TO_BSF;
    412	/* setup ccws */
    413	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
    414			  device->modeset_byte);
    415	ccw = tape_ccw_repeat(ccw, BACKSPACEFILE, mt_count);
    416	ccw = tape_ccw_end(ccw, NOP, 0, NULL);
    417	/* execute it */
    418	rc = tape_do_io_free(device, request);
    419	if (rc == 0) {
    420		rc = tape_mtop(device, MTFSR, 1);
    421		if (rc > 0)
    422			rc = 0;
    423	}
    424	return rc;
    425}
    426
    427/*
    428 * MTFSFM: Forward space over 'count' file marks.
    429 * The tape is positioned at the BOT (Begin Of Tape) side
    430 * of the last skipped file mark.
    431 */
    432int
    433tape_std_mtfsfm(struct tape_device *device, int mt_count)
    434{
    435	struct tape_request *request;
    436	struct ccw1 *ccw;
    437	int rc;
    438
    439	request = tape_alloc_request(mt_count + 2, 0);
    440	if (IS_ERR(request))
    441		return PTR_ERR(request);
    442	request->op = TO_FSF;
    443	/* setup ccws */
    444	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
    445			  device->modeset_byte);
    446	ccw = tape_ccw_repeat(ccw, FORSPACEFILE, mt_count);
    447	ccw = tape_ccw_end(ccw, NOP, 0, NULL);
    448	/* execute it */
    449	rc = tape_do_io_free(device, request);
    450	if (rc == 0) {
    451		rc = tape_mtop(device, MTBSR, 1);
    452		if (rc > 0)
    453			rc = 0;
    454	}
    455
    456	return rc;
    457}
    458
    459/*
    460 * MTREW: Rewind the tape.
    461 */
    462int
    463tape_std_mtrew(struct tape_device *device, int mt_count)
    464{
    465	struct tape_request *request;
    466
    467	request = tape_alloc_request(3, 0);
    468	if (IS_ERR(request))
    469		return PTR_ERR(request);
    470	request->op = TO_REW;
    471	/* setup ccws */
    472	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
    473		    device->modeset_byte);
    474	tape_ccw_cc(request->cpaddr + 1, REWIND, 0, NULL);
    475	tape_ccw_end(request->cpaddr + 2, NOP, 0, NULL);
    476
    477	/* execute it */
    478	return tape_do_io_free(device, request);
    479}
    480
    481/*
    482 * MTOFFL: Rewind the tape and put the drive off-line.
    483 * Implement 'rewind unload'
    484 */
    485int
    486tape_std_mtoffl(struct tape_device *device, int mt_count)
    487{
    488	struct tape_request *request;
    489
    490	request = tape_alloc_request(3, 0);
    491	if (IS_ERR(request))
    492		return PTR_ERR(request);
    493	request->op = TO_RUN;
    494	/* setup ccws */
    495	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
    496	tape_ccw_cc(request->cpaddr + 1, REWIND_UNLOAD, 0, NULL);
    497	tape_ccw_end(request->cpaddr + 2, NOP, 0, NULL);
    498
    499	/* execute it */
    500	return tape_do_io_free(device, request);
    501}
    502
    503/*
    504 * MTNOP: 'No operation'.
    505 */
    506int
    507tape_std_mtnop(struct tape_device *device, int mt_count)
    508{
    509	struct tape_request *request;
    510
    511	request = tape_alloc_request(2, 0);
    512	if (IS_ERR(request))
    513		return PTR_ERR(request);
    514	request->op = TO_NOP;
    515	/* setup ccws */
    516	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
    517	tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
    518	/* execute it */
    519	return tape_do_io_free(device, request);
    520}
    521
    522/*
    523 * MTEOM: positions at the end of the portion of the tape already used
    524 * for recordind data. MTEOM positions after the last file mark, ready for
    525 * appending another file.
    526 */
    527int
    528tape_std_mteom(struct tape_device *device, int mt_count)
    529{
    530	int rc;
    531
    532	/*
    533	 * Seek from the beginning of tape (rewind).
    534	 */
    535	if ((rc = tape_mtop(device, MTREW, 1)) < 0)
    536		return rc;
    537
    538	/*
    539	 * The logical end of volume is given by two sewuential tapemarks.
    540	 * Look for this by skipping to the next file (over one tapemark)
    541	 * and then test for another one (fsr returns 1 if a tapemark was
    542	 * encountered).
    543	 */
    544	do {
    545		if ((rc = tape_mtop(device, MTFSF, 1)) < 0)
    546			return rc;
    547		if ((rc = tape_mtop(device, MTFSR, 1)) < 0)
    548			return rc;
    549	} while (rc == 0);
    550
    551	return tape_mtop(device, MTBSR, 1);
    552}
    553
    554/*
    555 * MTRETEN: Retension the tape, i.e. forward space to end of tape and rewind.
    556 */
    557int
    558tape_std_mtreten(struct tape_device *device, int mt_count)
    559{
    560	struct tape_request *request;
    561
    562	request = tape_alloc_request(4, 0);
    563	if (IS_ERR(request))
    564		return PTR_ERR(request);
    565	request->op = TO_FSF;
    566	/* setup ccws */
    567	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
    568	tape_ccw_cc(request->cpaddr + 1,FORSPACEFILE, 0, NULL);
    569	tape_ccw_cc(request->cpaddr + 2, NOP, 0, NULL);
    570	tape_ccw_end(request->cpaddr + 3, CCW_CMD_TIC, 0, request->cpaddr);
    571	/* execute it, MTRETEN rc gets ignored */
    572	tape_do_io_interruptible(device, request);
    573	tape_free_request(request);
    574	return tape_mtop(device, MTREW, 1);
    575}
    576
    577/*
    578 * MTERASE: erases the tape.
    579 */
    580int
    581tape_std_mterase(struct tape_device *device, int mt_count)
    582{
    583	struct tape_request *request;
    584
    585	request = tape_alloc_request(6, 0);
    586	if (IS_ERR(request))
    587		return PTR_ERR(request);
    588	request->op = TO_DSE;
    589	/* setup ccws */
    590	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
    591	tape_ccw_cc(request->cpaddr + 1, REWIND, 0, NULL);
    592	tape_ccw_cc(request->cpaddr + 2, ERASE_GAP, 0, NULL);
    593	tape_ccw_cc(request->cpaddr + 3, DATA_SEC_ERASE, 0, NULL);
    594	tape_ccw_cc(request->cpaddr + 4, REWIND, 0, NULL);
    595	tape_ccw_end(request->cpaddr + 5, NOP, 0, NULL);
    596
    597	/* execute it */
    598	return tape_do_io_free(device, request);
    599}
    600
    601/*
    602 * MTUNLOAD: Rewind the tape and unload it.
    603 */
    604int
    605tape_std_mtunload(struct tape_device *device, int mt_count)
    606{
    607	return tape_mtop(device, MTOFFL, mt_count);
    608}
    609
    610/*
    611 * MTCOMPRESSION: used to enable compression.
    612 * Sets the IDRC on/off.
    613 */
    614int
    615tape_std_mtcompression(struct tape_device *device, int mt_count)
    616{
    617	struct tape_request *request;
    618
    619	if (mt_count < 0 || mt_count > 1) {
    620		DBF_EXCEPTION(6, "xcom parm\n");
    621		return -EINVAL;
    622	}
    623	request = tape_alloc_request(2, 0);
    624	if (IS_ERR(request))
    625		return PTR_ERR(request);
    626	request->op = TO_NOP;
    627	/* setup ccws */
    628	if (mt_count == 0)
    629		*device->modeset_byte &= ~0x08;
    630	else
    631		*device->modeset_byte |= 0x08;
    632	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
    633	tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
    634	/* execute it */
    635	return tape_do_io_free(device, request);
    636}
    637
    638/*
    639 * Read Block
    640 */
    641struct tape_request *
    642tape_std_read_block(struct tape_device *device, size_t count)
    643{
    644	struct tape_request *request;
    645
    646	/*
    647	 * We have to alloc 4 ccws in order to be able to transform request
    648	 * into a read backward request in error case.
    649	 */
    650	request = tape_alloc_request(4, 0);
    651	if (IS_ERR(request)) {
    652		DBF_EXCEPTION(6, "xrbl fail");
    653		return request;
    654	}
    655	request->op = TO_RFO;
    656	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
    657	tape_ccw_end_idal(request->cpaddr + 1, READ_FORWARD,
    658			  device->char_data.idal_buf);
    659	DBF_EVENT(6, "xrbl ccwg\n");
    660	return request;
    661}
    662
    663/*
    664 * Read Block backward transformation function.
    665 */
    666void
    667tape_std_read_backward(struct tape_device *device, struct tape_request *request)
    668{
    669	/*
    670	 * We have allocated 4 ccws in tape_std_read, so we can now
    671	 * transform the request to a read backward, followed by a
    672	 * forward space block.
    673	 */
    674	request->op = TO_RBA;
    675	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
    676	tape_ccw_cc_idal(request->cpaddr + 1, READ_BACKWARD,
    677			 device->char_data.idal_buf);
    678	tape_ccw_cc(request->cpaddr + 2, FORSPACEBLOCK, 0, NULL);
    679	tape_ccw_end(request->cpaddr + 3, NOP, 0, NULL);
    680	DBF_EVENT(6, "xrop ccwg");}
    681
    682/*
    683 * Write Block
    684 */
    685struct tape_request *
    686tape_std_write_block(struct tape_device *device, size_t count)
    687{
    688	struct tape_request *request;
    689
    690	request = tape_alloc_request(2, 0);
    691	if (IS_ERR(request)) {
    692		DBF_EXCEPTION(6, "xwbl fail\n");
    693		return request;
    694	}
    695	request->op = TO_WRI;
    696	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
    697	tape_ccw_end_idal(request->cpaddr + 1, WRITE_CMD,
    698			  device->char_data.idal_buf);
    699	DBF_EVENT(6, "xwbl ccwg\n");
    700	return request;
    701}
    702
    703/*
    704 * This routine is called by frontend after an ENOSP on write
    705 */
    706void
    707tape_std_process_eov(struct tape_device *device)
    708{
    709	/*
    710	 * End of volume: We have to backspace the last written record, then
    711	 * we TRY to write a tapemark and then backspace over the written TM
    712	 */
    713	if (tape_mtop(device, MTBSR, 1) == 0 &&
    714	    tape_mtop(device, MTWEOF, 1) == 0) {
    715		tape_mtop(device, MTBSR, 1);
    716	}
    717}
    718
    719EXPORT_SYMBOL(tape_std_assign);
    720EXPORT_SYMBOL(tape_std_unassign);
    721EXPORT_SYMBOL(tape_std_display);
    722EXPORT_SYMBOL(tape_std_read_block_id);
    723EXPORT_SYMBOL(tape_std_mtload);
    724EXPORT_SYMBOL(tape_std_mtsetblk);
    725EXPORT_SYMBOL(tape_std_mtreset);
    726EXPORT_SYMBOL(tape_std_mtfsf);
    727EXPORT_SYMBOL(tape_std_mtfsr);
    728EXPORT_SYMBOL(tape_std_mtbsr);
    729EXPORT_SYMBOL(tape_std_mtweof);
    730EXPORT_SYMBOL(tape_std_mtbsfm);
    731EXPORT_SYMBOL(tape_std_mtbsf);
    732EXPORT_SYMBOL(tape_std_mtfsfm);
    733EXPORT_SYMBOL(tape_std_mtrew);
    734EXPORT_SYMBOL(tape_std_mtoffl);
    735EXPORT_SYMBOL(tape_std_mtnop);
    736EXPORT_SYMBOL(tape_std_mteom);
    737EXPORT_SYMBOL(tape_std_mtreten);
    738EXPORT_SYMBOL(tape_std_mterase);
    739EXPORT_SYMBOL(tape_std_mtunload);
    740EXPORT_SYMBOL(tape_std_mtcompression);
    741EXPORT_SYMBOL(tape_std_read_block);
    742EXPORT_SYMBOL(tape_std_read_backward);
    743EXPORT_SYMBOL(tape_std_write_block);
    744EXPORT_SYMBOL(tape_std_process_eov);