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1// SPDX-License-Identifier: GPL-2.02/*3 * 3215 line mode terminal driver.4 *5 * Copyright IBM Corp. 1999, 20096 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>7 *8 * Updated:9 *  Aug-2000: Added tab support10 *	      Dan Morrison, IBM Corporation <dmorriso@cse.buffalo.edu>11 */12 13#include <linux/types.h>14#include <linux/kdev_t.h>15#include <linux/tty.h>16#include <linux/tty_flip.h>17#include <linux/vt_kern.h>18#include <linux/init.h>19#include <linux/console.h>20#include <linux/interrupt.h>21#include <linux/err.h>22#include <linux/panic_notifier.h>23#include <linux/reboot.h>24#include <linux/serial.h> /* ASYNC_* flags */25#include <linux/slab.h>26#include <asm/ccwdev.h>27#include <asm/cio.h>28#include <linux/io.h>29#include <asm/ebcdic.h>30#include <linux/uaccess.h>31#include <asm/delay.h>32#include <asm/cpcmd.h>33#include <asm/setup.h>34 35#include "ctrlchar.h"36 37#define NR_3215		    138#define NR_3215_REQ	    (4*NR_3215)39#define RAW3215_BUFFER_SIZE 65536     /* output buffer size */40#define RAW3215_INBUF_SIZE  256	      /* input buffer size */41#define RAW3215_MIN_SPACE   128	      /* minimum free space for wakeup */42#define RAW3215_MIN_WRITE   1024      /* min. length for immediate output */43#define RAW3215_MAX_BYTES   3968      /* max. bytes to write with one ssch */44#define RAW3215_MAX_NEWLINE 50	      /* max. lines to write with one ssch */45#define RAW3215_NR_CCWS	    346#define RAW3215_TIMEOUT	    HZ/10     /* time for delayed output */47 48#define RAW3215_FIXED	    1	      /* 3215 console device is not be freed */49#define RAW3215_WORKING	    4	      /* set if a request is being worked on */50#define RAW3215_THROTTLED   8	      /* set if reading is disabled */51#define RAW3215_STOPPED	    16	      /* set if writing is disabled */52#define RAW3215_TIMER_RUNS  64	      /* set if the output delay timer is on */53#define RAW3215_FLUSHING    128	      /* set to flush buffer (no delay) */54 55#define TAB_STOP_SIZE	    8	      /* tab stop size */56 57/*58 * Request types for a 3215 device59 */60enum raw3215_type {61	RAW3215_FREE, RAW3215_READ, RAW3215_WRITE62};63 64/*65 * Request structure for a 3215 device66 */67struct raw3215_req {68	enum raw3215_type type;	      /* type of the request */69	int start, len;		      /* start index & len in output buffer */70	int delayable;		      /* indication to wait for more data */71	int residual;		      /* residual count for read request */72	struct ccw1 ccws[RAW3215_NR_CCWS]; /* space for the channel program */73	struct raw3215_info *info;    /* pointer to main structure */74	struct raw3215_req *next;     /* pointer to next request */75} __attribute__ ((aligned(8)));76 77struct raw3215_info {78	struct tty_port port;79	struct ccw_device *cdev;      /* device for tty driver */80	spinlock_t *lock;	      /* pointer to irq lock */81	int flags;		      /* state flags */82	u8 *buffer;		      /* pointer to output buffer */83	u8 *inbuf;		      /* pointer to input buffer */84	int head;		      /* first free byte in output buffer */85	int count;		      /* number of bytes in output buffer */86	int written;		      /* number of bytes in write requests */87	struct raw3215_req *queued_read; /* pointer to queued read requests */88	struct raw3215_req *queued_write;/* pointer to queued write requests */89	wait_queue_head_t empty_wait; /* wait queue for flushing */90	struct timer_list timer;      /* timer for delayed output */91	int line_pos;		      /* position on the line (for tabs) */92};93 94/* array of 3215 devices structures */95static struct raw3215_info *raw3215[NR_3215];96/* spinlock to protect the raw3215 array */97static DEFINE_SPINLOCK(raw3215_device_lock);98/* list of free request structures */99static struct raw3215_req *raw3215_freelist;100/* spinlock to protect free list */101static DEFINE_SPINLOCK(raw3215_freelist_lock);102 103static struct tty_driver *tty3215_driver;104static bool con3215_drop = true;105 106/*107 * Get a request structure from the free list108 */109static inline struct raw3215_req *raw3215_alloc_req(void)110{111	struct raw3215_req *req;112	unsigned long flags;113 114	spin_lock_irqsave(&raw3215_freelist_lock, flags);115	req = raw3215_freelist;116	raw3215_freelist = req->next;117	spin_unlock_irqrestore(&raw3215_freelist_lock, flags);118	return req;119}120 121/*122 * Put a request structure back to the free list123 */124static inline void raw3215_free_req(struct raw3215_req *req)125{126	unsigned long flags;127 128	if (req->type == RAW3215_FREE)129		return;		/* don't free a free request */130	req->type = RAW3215_FREE;131	spin_lock_irqsave(&raw3215_freelist_lock, flags);132	req->next = raw3215_freelist;133	raw3215_freelist = req;134	spin_unlock_irqrestore(&raw3215_freelist_lock, flags);135}136 137/*138 * Set up a read request that reads up to 160 byte from the 3215 device.139 * If there is a queued read request it is used, but that shouldn't happen140 * because a 3215 terminal won't accept a new read before the old one is141 * completed.142 */143static void raw3215_mk_read_req(struct raw3215_info *raw)144{145	struct raw3215_req *req;146	struct ccw1 *ccw;147 148	/* there can only be ONE read request at a time */149	req = raw->queued_read;150	if (req == NULL) {151		/* no queued read request, use new req structure */152		req = raw3215_alloc_req();153		req->type = RAW3215_READ;154		req->info = raw;155		raw->queued_read = req;156	}157 158	ccw = req->ccws;159	ccw->cmd_code = 0x0A; /* read inquiry */160	ccw->flags = 0x20;    /* ignore incorrect length */161	ccw->count = 160;162	ccw->cda = virt_to_dma32(raw->inbuf);163}164 165/*166 * Set up a write request with the information from the main structure.167 * A ccw chain is created that writes as much as possible from the output168 * buffer to the 3215 device. If a queued write exists it is replaced by169 * the new, probably lengthened request.170 */171static void raw3215_mk_write_req(struct raw3215_info *raw)172{173	struct raw3215_req *req;174	struct ccw1 *ccw;175	int len, count, ix, lines;176 177	if (raw->count <= raw->written)178		return;179	/* check if there is a queued write request */180	req = raw->queued_write;181	if (req == NULL) {182		/* no queued write request, use new req structure */183		req = raw3215_alloc_req();184		req->type = RAW3215_WRITE;185		req->info = raw;186		raw->queued_write = req;187	} else {188		raw->written -= req->len;189	}190 191	ccw = req->ccws;192	req->start = (raw->head - raw->count + raw->written) &193		     (RAW3215_BUFFER_SIZE - 1);194	/*195	 * now we have to count newlines. We can at max accept196	 * RAW3215_MAX_NEWLINE newlines in a single ssch due to197	 * a restriction in VM198	 */199	lines = 0;200	ix = req->start;201	while (lines < RAW3215_MAX_NEWLINE && ix != raw->head) {202		if (raw->buffer[ix] == 0x15)203			lines++;204		ix = (ix + 1) & (RAW3215_BUFFER_SIZE - 1);205	}206	len = ((ix - 1 - req->start) & (RAW3215_BUFFER_SIZE - 1)) + 1;207	if (len > RAW3215_MAX_BYTES)208		len = RAW3215_MAX_BYTES;209	req->len = len;210	raw->written += len;211 212	/* set the indication if we should try to enlarge this request */213	req->delayable = (ix == raw->head) && (len < RAW3215_MIN_WRITE);214 215	ix = req->start;216	while (len > 0) {217		if (ccw > req->ccws)218			ccw[-1].flags |= 0x40; /* use command chaining */219		ccw->cmd_code = 0x01; /* write, auto carrier return */220		ccw->flags = 0x20;    /* ignore incorrect length ind.  */221		ccw->cda = virt_to_dma32(raw->buffer + ix);222		count = len;223		if (ix + count > RAW3215_BUFFER_SIZE)224			count = RAW3215_BUFFER_SIZE - ix;225		ccw->count = count;226		len -= count;227		ix = (ix + count) & (RAW3215_BUFFER_SIZE - 1);228		ccw++;229	}230	/*231	 * Add a NOP to the channel program. 3215 devices are purely232	 * emulated and its much better to avoid the channel end233	 * interrupt in this case.234	 */235	if (ccw > req->ccws)236		ccw[-1].flags |= 0x40; /* use command chaining */237	ccw->cmd_code = 0x03; /* NOP */238	ccw->flags = 0;239	ccw->cda = 0;240	ccw->count = 1;241}242 243/*244 * Start a read or a write request245 */246static void raw3215_start_io(struct raw3215_info *raw)247{248	struct raw3215_req *req;249	int res;250 251	req = raw->queued_read;252	if (req != NULL &&253	    !(raw->flags & (RAW3215_WORKING | RAW3215_THROTTLED))) {254		/* dequeue request */255		raw->queued_read = NULL;256		res = ccw_device_start(raw->cdev, req->ccws,257				       (unsigned long) req, 0, 0);258		if (res != 0) {259			/* do_IO failed, put request back to queue */260			raw->queued_read = req;261		} else {262			raw->flags |= RAW3215_WORKING;263		}264	}265	req = raw->queued_write;266	if (req != NULL &&267	    !(raw->flags & (RAW3215_WORKING | RAW3215_STOPPED))) {268		/* dequeue request */269		raw->queued_write = NULL;270		res = ccw_device_start(raw->cdev, req->ccws,271				       (unsigned long) req, 0, 0);272		if (res != 0) {273			/* do_IO failed, put request back to queue */274			raw->queued_write = req;275		} else {276			raw->flags |= RAW3215_WORKING;277		}278	}279}280 281/*282 * Function to start a delayed output after RAW3215_TIMEOUT seconds283 */284static void raw3215_timeout(struct timer_list *t)285{286	struct raw3215_info *raw = from_timer(raw, t, timer);287	unsigned long flags;288 289	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);290	raw->flags &= ~RAW3215_TIMER_RUNS;291	raw3215_mk_write_req(raw);292	raw3215_start_io(raw);293	if ((raw->queued_read || raw->queued_write) &&294	    !(raw->flags & RAW3215_WORKING) &&295	    !(raw->flags & RAW3215_TIMER_RUNS)) {296		raw->timer.expires = RAW3215_TIMEOUT + jiffies;297		add_timer(&raw->timer);298		raw->flags |= RAW3215_TIMER_RUNS;299	}300	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);301}302 303/*304 * Function to conditionally start an IO. A read is started immediately,305 * a write is only started immediately if the flush flag is on or the306 * amount of data is bigger than RAW3215_MIN_WRITE. If a write is not307 * done immediately a timer is started with a delay of RAW3215_TIMEOUT.308 */309static inline void raw3215_try_io(struct raw3215_info *raw)310{311	if (!tty_port_initialized(&raw->port))312		return;313	if (raw->queued_read != NULL)314		raw3215_start_io(raw);315	else if (raw->queued_write != NULL) {316		if ((raw->queued_write->delayable == 0) ||317		    (raw->flags & RAW3215_FLUSHING)) {318			/* execute write requests bigger than minimum size */319			raw3215_start_io(raw);320		}321	}322	if ((raw->queued_read || raw->queued_write) &&323	    !(raw->flags & RAW3215_WORKING) &&324	    !(raw->flags & RAW3215_TIMER_RUNS)) {325		raw->timer.expires = RAW3215_TIMEOUT + jiffies;326		add_timer(&raw->timer);327		raw->flags |= RAW3215_TIMER_RUNS;328	}329}330 331/*332 * Try to start the next IO and wake up processes waiting on the tty.333 */334static void raw3215_next_io(struct raw3215_info *raw, struct tty_struct *tty)335{336	raw3215_mk_write_req(raw);337	raw3215_try_io(raw);338	if (tty && RAW3215_BUFFER_SIZE - raw->count >= RAW3215_MIN_SPACE)339		tty_wakeup(tty);340}341 342/*343 * Interrupt routine, called from common io layer344 */345static void raw3215_irq(struct ccw_device *cdev, unsigned long intparm,346			struct irb *irb)347{348	struct raw3215_info *raw;349	struct raw3215_req *req;350	struct tty_struct *tty;351	int cstat, dstat;352	int count;353 354	raw = dev_get_drvdata(&cdev->dev);355	req = (struct raw3215_req *) intparm;356	tty = tty_port_tty_get(&raw->port);357	cstat = irb->scsw.cmd.cstat;358	dstat = irb->scsw.cmd.dstat;359	if (cstat != 0)360		raw3215_next_io(raw, tty);361	if (dstat & 0x01) { /* we got a unit exception */362		dstat &= ~0x01;	 /* we can ignore it */363	}364	switch (dstat) {365	case 0x80:366		if (cstat != 0)367			break;368		/* Attention interrupt, someone hit the enter key */369		raw3215_mk_read_req(raw);370		raw3215_next_io(raw, tty);371		break;372	case 0x08:373	case 0x0C:374		/* Channel end interrupt. */375		if ((raw = req->info) == NULL)376			goto put_tty;	     /* That shouldn't happen ... */377		if (req->type == RAW3215_READ) {378			/* store residual count, then wait for device end */379			req->residual = irb->scsw.cmd.count;380		}381		if (dstat == 0x08)382			break;383		fallthrough;384	case 0x04:385		/* Device end interrupt. */386		if ((raw = req->info) == NULL)387			goto put_tty;	     /* That shouldn't happen ... */388		if (req->type == RAW3215_READ && tty != NULL) {389			unsigned int cchar;390 391			count = 160 - req->residual;392			EBCASC(raw->inbuf, count);393			cchar = ctrlchar_handle(raw->inbuf, count, tty);394			switch (cchar & CTRLCHAR_MASK) {395			case CTRLCHAR_SYSRQ:396				break;397 398			case CTRLCHAR_CTRL:399				tty_insert_flip_char(&raw->port, cchar,400						TTY_NORMAL);401				tty_flip_buffer_push(&raw->port);402				break;403 404			case CTRLCHAR_NONE:405				if (count < 2 ||406				    (strncmp(raw->inbuf+count-2, "\252n", 2) &&407				     strncmp(raw->inbuf+count-2, "^n", 2)) ) {408					/* add the auto \n */409					raw->inbuf[count] = '\n';410					count++;411				} else412					count -= 2;413				tty_insert_flip_string(&raw->port, raw->inbuf,414						count);415				tty_flip_buffer_push(&raw->port);416				break;417			}418		} else if (req->type == RAW3215_WRITE) {419			raw->count -= req->len;420			raw->written -= req->len;421		}422		raw->flags &= ~RAW3215_WORKING;423		raw3215_free_req(req);424		/* check for empty wait */425		if (waitqueue_active(&raw->empty_wait) &&426		    raw->queued_write == NULL &&427		    raw->queued_read == NULL) {428			wake_up_interruptible(&raw->empty_wait);429		}430		raw3215_next_io(raw, tty);431		break;432	default:433		/* Strange interrupt, I'll do my best to clean up */434		if (req != NULL && req->type != RAW3215_FREE) {435			if (req->type == RAW3215_WRITE) {436				raw->count -= req->len;437				raw->written -= req->len;438			}439			raw->flags &= ~RAW3215_WORKING;440			raw3215_free_req(req);441		}442		raw3215_next_io(raw, tty);443	}444put_tty:445	tty_kref_put(tty);446}447 448/*449 * Need to drop data to avoid blocking. Drop as much data as possible.450 * This is unqueued part in the buffer and the queued part in the request.451 * Also adjust the head position to append new data and set count452 * accordingly.453 *454 * Return number of bytes available in buffer.455 */456static unsigned int raw3215_drop(struct raw3215_info *raw)457{458	struct raw3215_req *req;459 460	req = raw->queued_write;461	if (req) {462		/* Drop queued data and delete request */463		raw->written -= req->len;464		raw3215_free_req(req);465		raw->queued_write = NULL;466	}467	raw->head = (raw->head - raw->count + raw->written) &468		    (RAW3215_BUFFER_SIZE - 1);469	raw->count = raw->written;470 471	return RAW3215_BUFFER_SIZE - raw->count;472}473 474/*475 * Wait until length bytes are available int the output buffer.476 * If drop mode is active and wait condition holds true, start dropping477 * data.478 * Has to be called with the s390irq lock held. Can be called479 * disabled.480 */481static unsigned int raw3215_make_room(struct raw3215_info *raw,482				      unsigned int length, bool drop)483{484	while (RAW3215_BUFFER_SIZE - raw->count < length) {485		if (drop)486			return raw3215_drop(raw);487 488		/* there might be a request pending */489		raw->flags |= RAW3215_FLUSHING;490		raw3215_mk_write_req(raw);491		raw3215_try_io(raw);492		raw->flags &= ~RAW3215_FLUSHING;493#ifdef CONFIG_TN3215_CONSOLE494		ccw_device_wait_idle(raw->cdev);495#endif496		/* Enough room freed up ? */497		if (RAW3215_BUFFER_SIZE - raw->count >= length)498			break;499		/* there might be another cpu waiting for the lock */500		spin_unlock(get_ccwdev_lock(raw->cdev));501		udelay(100);502		spin_lock(get_ccwdev_lock(raw->cdev));503	}504	return length;505}506 507#define	RAW3215_COUNT	1508#define	RAW3215_STORE	2509 510/*511 * Add text to console buffer. Find tabs in input and calculate size512 * including tab replacement.513 * This function operates in 2 different modes, depending on parameter514 * opmode:515 * RAW3215_COUNT: Get the size needed for the input string with516 *	proper tab replacement calculation.517 *	Return value is the number of bytes required to store the518 *	input. However no data is actually stored.519 *	The parameter todrop is not used.520 * RAW3215_STORE: Add data to the console buffer. The parameter todrop is521 *	valid and contains the number of bytes to be dropped from head of522 *	string	without blocking.523 *	Return value is the number of bytes copied.524 */525static unsigned int raw3215_addtext(const u8 *str, size_t length,526				    struct raw3215_info *raw, int opmode,527				    unsigned int todrop)528{529	unsigned int i, blanks, expanded_size = 0;530	unsigned int column = raw->line_pos;531	size_t c;532	u8 ch;533 534	if (opmode == RAW3215_COUNT)535		todrop = 0;536 537	for (c = 0; c < length; ++c) {538		blanks = 1;539		ch = str[c];540 541		switch (ch) {542		case '\n':543			expanded_size++;544			column = 0;545			break;546		case '\t':547			blanks = TAB_STOP_SIZE - (column % TAB_STOP_SIZE);548			column += blanks;549			expanded_size += blanks;550			ch = ' ';551			break;552		default:553			expanded_size++;554			column++;555			break;556		}557 558		if (opmode == RAW3215_COUNT)559			continue;560		if (todrop && expanded_size < todrop)	/* Drop head data */561			continue;562		for (i = 0; i < blanks; i++) {563			raw->buffer[raw->head] = _ascebc[ch];564			raw->head = (raw->head + 1) & (RAW3215_BUFFER_SIZE - 1);565			raw->count++;566		}567		raw->line_pos = column;568	}569	return expanded_size - todrop;570}571 572/*573 * String write routine for 3215 devices574 */575static void raw3215_write(struct raw3215_info *raw, const u8 *str,576			  size_t length)577{578	unsigned int count, avail;579	unsigned long flags;580 581	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);582 583	count = raw3215_addtext(str, length, raw, RAW3215_COUNT, 0);584 585	avail = raw3215_make_room(raw, count, con3215_drop);586	if (avail) {587		raw3215_addtext(str, length, raw, RAW3215_STORE,588				count - avail);589	}590	if (!(raw->flags & RAW3215_WORKING)) {591		raw3215_mk_write_req(raw);592		/* start or queue request */593		raw3215_try_io(raw);594	}595	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);596}597 598/*599 * Put character routine for 3215 devices600 */601static void raw3215_putchar(struct raw3215_info *raw, u8 ch)602{603	raw3215_write(raw, &ch, 1);604}605 606/*607 * Flush routine, it simply sets the flush flag and tries to start608 * pending IO.609 */610static void raw3215_flush_buffer(struct raw3215_info *raw)611{612	unsigned long flags;613 614	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);615	if (raw->count > 0) {616		raw->flags |= RAW3215_FLUSHING;617		raw3215_try_io(raw);618		raw->flags &= ~RAW3215_FLUSHING;619	}620	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);621}622 623/*624 * Fire up a 3215 device.625 */626static int raw3215_startup(struct raw3215_info *raw)627{628	unsigned long flags;629 630	if (tty_port_initialized(&raw->port))631		return 0;632	raw->line_pos = 0;633	tty_port_set_initialized(&raw->port, true);634	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);635	raw3215_try_io(raw);636	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);637 638	return 0;639}640 641/*642 * Shutdown a 3215 device.643 */644static void raw3215_shutdown(struct raw3215_info *raw)645{646	DECLARE_WAITQUEUE(wait, current);647	unsigned long flags;648 649	if (!tty_port_initialized(&raw->port) || (raw->flags & RAW3215_FIXED))650		return;651	/* Wait for outstanding requests, then free irq */652	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);653	if ((raw->flags & RAW3215_WORKING) ||654	    raw->queued_write != NULL ||655	    raw->queued_read != NULL) {656		add_wait_queue(&raw->empty_wait, &wait);657		set_current_state(TASK_INTERRUPTIBLE);658		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);659		schedule();660		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);661		remove_wait_queue(&raw->empty_wait, &wait);662		set_current_state(TASK_RUNNING);663		tty_port_set_initialized(&raw->port, true);664	}665	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);666}667 668static struct raw3215_info *raw3215_alloc_info(void)669{670	struct raw3215_info *info;671 672	info = kzalloc(sizeof(struct raw3215_info), GFP_KERNEL | GFP_DMA);673	if (!info)674		return NULL;675 676	info->buffer = kzalloc(RAW3215_BUFFER_SIZE, GFP_KERNEL | GFP_DMA);677	info->inbuf = kzalloc(RAW3215_INBUF_SIZE, GFP_KERNEL | GFP_DMA);678	if (!info->buffer || !info->inbuf) {679		kfree(info->inbuf);680		kfree(info->buffer);681		kfree(info);682		return NULL;683	}684 685	timer_setup(&info->timer, raw3215_timeout, 0);686	init_waitqueue_head(&info->empty_wait);687	tty_port_init(&info->port);688 689	return info;690}691 692static void raw3215_free_info(struct raw3215_info *raw)693{694	kfree(raw->inbuf);695	kfree(raw->buffer);696	tty_port_destroy(&raw->port);697	kfree(raw);698}699 700static int raw3215_probe(struct ccw_device *cdev)701{702	struct raw3215_info *raw;703	int line;704 705	/* Console is special. */706	if (raw3215[0] && (raw3215[0] == dev_get_drvdata(&cdev->dev)))707		return 0;708 709	raw = raw3215_alloc_info();710	if (raw == NULL)711		return -ENOMEM;712 713	raw->cdev = cdev;714	dev_set_drvdata(&cdev->dev, raw);715	cdev->handler = raw3215_irq;716 717	spin_lock(&raw3215_device_lock);718	for (line = 0; line < NR_3215; line++) {719		if (!raw3215[line]) {720			raw3215[line] = raw;721			break;722		}723	}724	spin_unlock(&raw3215_device_lock);725	if (line == NR_3215) {726		raw3215_free_info(raw);727		return -ENODEV;728	}729 730	return 0;731}732 733static void raw3215_remove(struct ccw_device *cdev)734{735	struct raw3215_info *raw;736	unsigned int line;737 738	ccw_device_set_offline(cdev);739	raw = dev_get_drvdata(&cdev->dev);740	if (raw) {741		spin_lock(&raw3215_device_lock);742		for (line = 0; line < NR_3215; line++)743			if (raw3215[line] == raw)744				break;745		raw3215[line] = NULL;746		spin_unlock(&raw3215_device_lock);747		dev_set_drvdata(&cdev->dev, NULL);748		raw3215_free_info(raw);749	}750}751 752static int raw3215_set_online(struct ccw_device *cdev)753{754	struct raw3215_info *raw;755 756	raw = dev_get_drvdata(&cdev->dev);757	if (!raw)758		return -ENODEV;759 760	return raw3215_startup(raw);761}762 763static int raw3215_set_offline(struct ccw_device *cdev)764{765	struct raw3215_info *raw;766 767	raw = dev_get_drvdata(&cdev->dev);768	if (!raw)769		return -ENODEV;770 771	raw3215_shutdown(raw);772 773	return 0;774}775 776static struct ccw_device_id raw3215_id[] = {777	{ CCW_DEVICE(0x3215, 0) },778	{ /* end of list */ },779};780 781static ssize_t con_drop_store(struct device_driver *dev, const char *buf, size_t count)782{783	bool drop;784	int rc;785 786	rc = kstrtobool(buf, &drop);787	if (!rc)788		con3215_drop = drop;789	return rc ?: count;790}791 792static ssize_t con_drop_show(struct device_driver *dev, char *buf)793{794	return sysfs_emit(buf, "%d\n", con3215_drop ? 1 : 0);795}796 797static DRIVER_ATTR_RW(con_drop);798 799static struct attribute *con3215_drv_attrs[] = {800	&driver_attr_con_drop.attr,801	NULL,802};803 804static struct attribute_group con3215_drv_attr_group = {805	.attrs = con3215_drv_attrs,806	NULL,807};808 809static const struct attribute_group *con3215_drv_attr_groups[] = {810	&con3215_drv_attr_group,811	NULL,812};813 814static struct ccw_driver raw3215_ccw_driver = {815	.driver = {816		.name	= "3215",817		.groups = con3215_drv_attr_groups,818		.owner	= THIS_MODULE,819	},820	.ids		= raw3215_id,821	.probe		= &raw3215_probe,822	.remove		= &raw3215_remove,823	.set_online	= &raw3215_set_online,824	.set_offline	= &raw3215_set_offline,825	.int_class	= IRQIO_C15,826};827 828static void handle_write(struct raw3215_info *raw, const u8 *str, size_t count)829{830	while (count > 0) {831		size_t i = min_t(size_t, count, RAW3215_BUFFER_SIZE - 1);832		raw3215_write(raw, str, i);833		count -= i;834		str += i;835	}836}837 838#ifdef CONFIG_TN3215_CONSOLE839/*840 * Write a string to the 3215 console841 */842static void con3215_write(struct console *co, const char *str, unsigned int count)843{844	handle_write(raw3215[0], str, count);845}846 847static struct tty_driver *con3215_device(struct console *c, int *index)848{849	*index = c->index;850	return tty3215_driver;851}852 853/*854 * The below function is called as a panic/reboot notifier before the855 * system enters a disabled, endless loop.856 *857 * Notice we must use the spin_trylock() alternative, to prevent lockups858 * in atomic context (panic routine runs with secondary CPUs, local IRQs859 * and preemption disabled).860 */861static int con3215_notify(struct notifier_block *self,862			  unsigned long event, void *data)863{864	struct raw3215_info *raw;865	unsigned long flags;866 867	raw = raw3215[0];  /* console 3215 is the first one */868	if (!spin_trylock_irqsave(get_ccwdev_lock(raw->cdev), flags))869		return NOTIFY_DONE;870	raw3215_make_room(raw, RAW3215_BUFFER_SIZE, false);871	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);872 873	return NOTIFY_DONE;874}875 876static struct notifier_block on_panic_nb = {877	.notifier_call = con3215_notify,878	.priority = INT_MIN + 1, /* run the callback late */879};880 881static struct notifier_block on_reboot_nb = {882	.notifier_call = con3215_notify,883	.priority = INT_MIN + 1, /* run the callback late */884};885 886/*887 *  The console structure for the 3215 console888 */889static struct console con3215 = {890	.name	 = "ttyS",891	.write	 = con3215_write,892	.device	 = con3215_device,893	.flags	 = CON_PRINTBUFFER,894};895 896/*897 * 3215 console initialization code called from console_init().898 */899static int __init con3215_init(void)900{901	struct ccw_device *cdev;902	struct raw3215_info *raw;903	struct raw3215_req *req;904	int i;905 906	/* Check if 3215 is to be the console */907	if (!CONSOLE_IS_3215)908		return -ENODEV;909 910	/* Set the console mode for VM */911	if (MACHINE_IS_VM) {912		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);913		cpcmd("TERM AUTOCR OFF", NULL, 0, NULL);914	}915 916	/* allocate 3215 request structures */917	raw3215_freelist = NULL;918	for (i = 0; i < NR_3215_REQ; i++) {919		req = kzalloc(sizeof(struct raw3215_req), GFP_KERNEL | GFP_DMA);920		if (!req)921			return -ENOMEM;922		req->next = raw3215_freelist;923		raw3215_freelist = req;924	}925 926	cdev = ccw_device_create_console(&raw3215_ccw_driver);927	if (IS_ERR(cdev))928		return -ENODEV;929 930	raw3215[0] = raw = raw3215_alloc_info();931	raw->cdev = cdev;932	dev_set_drvdata(&cdev->dev, raw);933	cdev->handler = raw3215_irq;934 935	raw->flags |= RAW3215_FIXED;936	if (ccw_device_enable_console(cdev)) {937		ccw_device_destroy_console(cdev);938		raw3215_free_info(raw);939		raw3215[0] = NULL;940		return -ENODEV;941	}942 943	/* Request the console irq */944	if (raw3215_startup(raw) != 0) {945		raw3215_free_info(raw);946		raw3215[0] = NULL;947		return -ENODEV;948	}949	atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);950	register_reboot_notifier(&on_reboot_nb);951	register_console(&con3215);952	return 0;953}954console_initcall(con3215_init);955#endif956 957static int tty3215_install(struct tty_driver *driver, struct tty_struct *tty)958{959	struct raw3215_info *raw;960 961	raw = raw3215[tty->index];962	if (raw == NULL)963		return -ENODEV;964 965	tty->driver_data = raw;966 967	return tty_port_install(&raw->port, driver, tty);968}969 970/*971 * tty3215_open972 *973 * This routine is called whenever a 3215 tty is opened.974 */975static int tty3215_open(struct tty_struct *tty, struct file * filp)976{977	struct raw3215_info *raw = tty->driver_data;978 979	tty_port_tty_set(&raw->port, tty);980 981	/*982	 * Start up 3215 device983	 */984	return raw3215_startup(raw);985}986 987/*988 * tty3215_close()989 *990 * This routine is called when the 3215 tty is closed. We wait991 * for the remaining request to be completed. Then we clean up.992 */993static void tty3215_close(struct tty_struct *tty, struct file * filp)994{995	struct raw3215_info *raw = tty->driver_data;996 997	if (raw == NULL || tty->count > 1)998		return;999	tty->closing = 1;1000	/* Shutdown the terminal */1001	raw3215_shutdown(raw);1002	tty->closing = 0;1003	tty_port_tty_set(&raw->port, NULL);1004}1005 1006/*1007 * Returns the amount of free space in the output buffer.1008 */1009static unsigned int tty3215_write_room(struct tty_struct *tty)1010{1011	struct raw3215_info *raw = tty->driver_data;1012 1013	/* Subtract TAB_STOP_SIZE to allow for a tab, 8 <<< 64K */1014	if ((RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE) >= 0)1015		return RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE;1016	else1017		return 0;1018}1019 1020/*1021 * String write routine for 3215 ttys1022 */1023static ssize_t tty3215_write(struct tty_struct *tty, const u8 *buf,1024			     size_t count)1025{1026	handle_write(tty->driver_data, buf, count);1027	return count;1028}1029 1030/*1031 * Put character routine for 3215 ttys1032 */1033static int tty3215_put_char(struct tty_struct *tty, u8 ch)1034{1035	struct raw3215_info *raw = tty->driver_data;1036 1037	raw3215_putchar(raw, ch);1038 1039	return 1;1040}1041 1042static void tty3215_flush_chars(struct tty_struct *tty)1043{1044}1045 1046/*1047 * Returns the number of characters in the output buffer1048 */1049static unsigned int tty3215_chars_in_buffer(struct tty_struct *tty)1050{1051	struct raw3215_info *raw = tty->driver_data;1052 1053	return raw->count;1054}1055 1056static void tty3215_flush_buffer(struct tty_struct *tty)1057{1058	struct raw3215_info *raw = tty->driver_data;1059 1060	raw3215_flush_buffer(raw);1061	tty_wakeup(tty);1062}1063 1064/*1065 * Disable reading from a 3215 tty1066 */1067static void tty3215_throttle(struct tty_struct *tty)1068{1069	struct raw3215_info *raw = tty->driver_data;1070 1071	raw->flags |= RAW3215_THROTTLED;1072}1073 1074/*1075 * Enable reading from a 3215 tty1076 */1077static void tty3215_unthrottle(struct tty_struct *tty)1078{1079	struct raw3215_info *raw = tty->driver_data;1080	unsigned long flags;1081 1082	if (raw->flags & RAW3215_THROTTLED) {1083		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);1084		raw->flags &= ~RAW3215_THROTTLED;1085		raw3215_try_io(raw);1086		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);1087	}1088}1089 1090/*1091 * Disable writing to a 3215 tty1092 */1093static void tty3215_stop(struct tty_struct *tty)1094{1095	struct raw3215_info *raw = tty->driver_data;1096 1097	raw->flags |= RAW3215_STOPPED;1098}1099 1100/*1101 * Enable writing to a 3215 tty1102 */1103static void tty3215_start(struct tty_struct *tty)1104{1105	struct raw3215_info *raw = tty->driver_data;1106	unsigned long flags;1107 1108	if (raw->flags & RAW3215_STOPPED) {1109		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);1110		raw->flags &= ~RAW3215_STOPPED;1111		raw3215_try_io(raw);1112		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);1113	}1114}1115 1116static const struct tty_operations tty3215_ops = {1117	.install = tty3215_install,1118	.open = tty3215_open,1119	.close = tty3215_close,1120	.write = tty3215_write,1121	.put_char = tty3215_put_char,1122	.flush_chars = tty3215_flush_chars,1123	.write_room = tty3215_write_room,1124	.chars_in_buffer = tty3215_chars_in_buffer,1125	.flush_buffer = tty3215_flush_buffer,1126	.throttle = tty3215_throttle,1127	.unthrottle = tty3215_unthrottle,1128	.stop = tty3215_stop,1129	.start = tty3215_start,1130};1131 1132static int __init con3215_setup_drop(char *str)1133{1134	bool drop;1135	int rc;1136 1137	rc = kstrtobool(str, &drop);1138	if (!rc)1139		con3215_drop = drop;1140	return rc;1141}1142early_param("con3215_drop", con3215_setup_drop);1143 1144/*1145 * 3215 tty registration code called from tty_init().1146 * Most kernel services (incl. kmalloc) are available at this poimt.1147 */1148static int __init tty3215_init(void)1149{1150	struct tty_driver *driver;1151	int ret;1152 1153	if (!CONSOLE_IS_3215)1154		return 0;1155 1156	driver = tty_alloc_driver(NR_3215, TTY_DRIVER_REAL_RAW);1157	if (IS_ERR(driver))1158		return PTR_ERR(driver);1159 1160	ret = ccw_driver_register(&raw3215_ccw_driver);1161	if (ret) {1162		tty_driver_kref_put(driver);1163		return ret;1164	}1165	/*1166	 * Initialize the tty_driver structure1167	 * Entries in tty3215_driver that are NOT initialized:1168	 * proc_entry, set_termios, flush_buffer, set_ldisc, write_proc1169	 */1170 1171	driver->driver_name = "tty3215";1172	driver->name = "ttyS";1173	driver->major = TTY_MAJOR;1174	driver->minor_start = 64;1175	driver->type = TTY_DRIVER_TYPE_SYSTEM;1176	driver->subtype = SYSTEM_TYPE_TTY;1177	driver->init_termios = tty_std_termios;1178	driver->init_termios.c_iflag = IGNBRK | IGNPAR;1179	driver->init_termios.c_oflag = ONLCR;1180	driver->init_termios.c_lflag = ISIG;1181	tty_set_operations(driver, &tty3215_ops);1182	ret = tty_register_driver(driver);1183	if (ret) {1184		tty_driver_kref_put(driver);1185		return ret;1186	}1187	tty3215_driver = driver;1188	return 0;1189}1190device_initcall(tty3215_init);1191