linux/drivers/s390/char/con3270.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * IBM/3270 Driver - console view.
   4 *
   5 * Author(s):
   6 *   Original 3270 Code for 2.4 written by Richard Hitt (UTS Global)
   7 *   Rewritten for 2.5 by Martin Schwidefsky <schwidefsky@de.ibm.com>
   8 *     Copyright IBM Corp. 2003, 2009
   9 */
  10
  11#include <linux/module.h>
  12#include <linux/console.h>
  13#include <linux/init.h>
  14#include <linux/interrupt.h>
  15#include <linux/list.h>
  16#include <linux/types.h>
  17#include <linux/slab.h>
  18#include <linux/err.h>
  19#include <linux/reboot.h>
  20
  21#include <asm/ccwdev.h>
  22#include <asm/cio.h>
  23#include <asm/cpcmd.h>
  24#include <asm/ebcdic.h>
  25
  26#include "raw3270.h"
  27#include "tty3270.h"
  28#include "ctrlchar.h"
  29
  30#define CON3270_OUTPUT_BUFFER_SIZE 1024
  31#define CON3270_STRING_PAGES 4
  32
  33static struct raw3270_fn con3270_fn;
  34
  35static bool auto_update = true;
  36module_param(auto_update, bool, 0);
  37
  38/*
  39 * Main 3270 console view data structure.
  40 */
  41struct con3270 {
  42        struct raw3270_view view;
  43        struct list_head freemem;       /* list of free memory for strings. */
  44
  45        /* Output stuff. */
  46        struct list_head lines;         /* list of lines. */
  47        struct list_head update;        /* list of lines to update. */
  48        int line_nr;                    /* line number for next update. */
  49        int nr_lines;                   /* # lines in list. */
  50        int nr_up;                      /* # lines up in history. */
  51        unsigned long update_flags;     /* Update indication bits. */
  52        struct string *cline;           /* current output line. */
  53        struct string *status;          /* last line of display. */
  54        struct raw3270_request *write;  /* single write request. */
  55        struct timer_list timer;
  56
  57        /* Input stuff. */
  58        struct string *input;           /* input string for read request. */
  59        struct raw3270_request *read;   /* single read request. */
  60        struct raw3270_request *kreset; /* single keyboard reset request. */
  61        struct tasklet_struct readlet;  /* tasklet to issue read request. */
  62};
  63
  64static struct con3270 *condev;
  65
  66/* con3270->update_flags. See con3270_update for details. */
  67#define CON_UPDATE_ERASE        1       /* Use EWRITEA instead of WRITE. */
  68#define CON_UPDATE_LIST         2       /* Update lines in tty3270->update. */
  69#define CON_UPDATE_STATUS       4       /* Update status line. */
  70#define CON_UPDATE_ALL          8       /* Recreate screen. */
  71
  72static void con3270_update(struct timer_list *);
  73
  74/*
  75 * Setup timeout for a device. On timeout trigger an update.
  76 */
  77static void con3270_set_timer(struct con3270 *cp, int expires)
  78{
  79        if (expires == 0)
  80                del_timer(&cp->timer);
  81        else
  82                mod_timer(&cp->timer, jiffies + expires);
  83}
  84
  85/*
  86 * The status line is the last line of the screen. It shows the string
  87 * "console view" in the lower left corner and "Running"/"More..."/"Holding"
  88 * in the lower right corner of the screen.
  89 */
  90static void
  91con3270_update_status(struct con3270 *cp)
  92{
  93        char *str;
  94
  95        str = (cp->nr_up != 0) ? "History" : "Running";
  96        memcpy(cp->status->string + 24, str, 7);
  97        codepage_convert(cp->view.ascebc, cp->status->string + 24, 7);
  98        cp->update_flags |= CON_UPDATE_STATUS;
  99}
 100
 101static void
 102con3270_create_status(struct con3270 *cp)
 103{
 104        static const unsigned char blueprint[] =
 105                { TO_SBA, 0, 0, TO_SF,TF_LOG,TO_SA,TAT_COLOR, TAC_GREEN,
 106                  'c','o','n','s','o','l','e',' ','v','i','e','w',
 107                  TO_RA,0,0,0,'R','u','n','n','i','n','g',TO_SF,TF_LOG };
 108
 109        cp->status = alloc_string(&cp->freemem, sizeof(blueprint));
 110        /* Copy blueprint to status line */
 111        memcpy(cp->status->string, blueprint, sizeof(blueprint));
 112        /* Set TO_RA addresses. */
 113        raw3270_buffer_address(cp->view.dev, cp->status->string + 1,
 114                               cp->view.cols * (cp->view.rows - 1));
 115        raw3270_buffer_address(cp->view.dev, cp->status->string + 21,
 116                               cp->view.cols * cp->view.rows - 8);
 117        /* Convert strings to ebcdic. */
 118        codepage_convert(cp->view.ascebc, cp->status->string + 8, 12);
 119        codepage_convert(cp->view.ascebc, cp->status->string + 24, 7);
 120}
 121
 122/*
 123 * Set output offsets to 3270 datastream fragment of a console string.
 124 */
 125static void
 126con3270_update_string(struct con3270 *cp, struct string *s, int nr)
 127{
 128        if (s->len < 4) {
 129                /* This indicates a bug, but printing a warning would
 130                 * cause a deadlock. */
 131                return;
 132        }
 133        if (s->string[s->len - 4] != TO_RA)
 134                return;
 135        raw3270_buffer_address(cp->view.dev, s->string + s->len - 3,
 136                               cp->view.cols * (nr + 1));
 137}
 138
 139/*
 140 * Rebuild update list to print all lines.
 141 */
 142static void
 143con3270_rebuild_update(struct con3270 *cp)
 144{
 145        struct string *s, *n;
 146        int nr;
 147
 148        /* 
 149         * Throw away update list and create a new one,
 150         * containing all lines that will fit on the screen.
 151         */
 152        list_for_each_entry_safe(s, n, &cp->update, update)
 153                list_del_init(&s->update);
 154        nr = cp->view.rows - 2 + cp->nr_up;
 155        list_for_each_entry_reverse(s, &cp->lines, list) {
 156                if (nr < cp->view.rows - 1)
 157                        list_add(&s->update, &cp->update);
 158                if (--nr < 0)
 159                        break;
 160        }
 161        cp->line_nr = 0;
 162        cp->update_flags |= CON_UPDATE_LIST;
 163}
 164
 165/*
 166 * Alloc string for size bytes. Free strings from history if necessary.
 167 */
 168static struct string *
 169con3270_alloc_string(struct con3270 *cp, size_t size)
 170{
 171        struct string *s, *n;
 172
 173        s = alloc_string(&cp->freemem, size);
 174        if (s)
 175                return s;
 176        list_for_each_entry_safe(s, n, &cp->lines, list) {
 177                list_del(&s->list);
 178                if (!list_empty(&s->update))
 179                        list_del(&s->update);
 180                cp->nr_lines--;
 181                if (free_string(&cp->freemem, s) >= size)
 182                        break;
 183        }
 184        s = alloc_string(&cp->freemem, size);
 185        BUG_ON(!s);
 186        if (cp->nr_up != 0 && cp->nr_up + cp->view.rows > cp->nr_lines) {
 187                cp->nr_up = cp->nr_lines - cp->view.rows + 1;
 188                con3270_rebuild_update(cp);
 189                con3270_update_status(cp);
 190        }
 191        return s;
 192}
 193
 194/*
 195 * Write completion callback.
 196 */
 197static void
 198con3270_write_callback(struct raw3270_request *rq, void *data)
 199{
 200        raw3270_request_reset(rq);
 201        xchg(&((struct con3270 *) rq->view)->write, rq);
 202}
 203
 204/*
 205 * Update console display.
 206 */
 207static void
 208con3270_update(struct timer_list *t)
 209{
 210        struct con3270 *cp = from_timer(cp, t, timer);
 211        struct raw3270_request *wrq;
 212        char wcc, prolog[6];
 213        unsigned long flags;
 214        unsigned long updated;
 215        struct string *s, *n;
 216        int rc;
 217
 218        if (!auto_update && !raw3270_view_active(&cp->view))
 219                return;
 220        if (cp->view.dev)
 221                raw3270_activate_view(&cp->view);
 222
 223        wrq = xchg(&cp->write, 0);
 224        if (!wrq) {
 225                con3270_set_timer(cp, 1);
 226                return;
 227        }
 228
 229        spin_lock_irqsave(&cp->view.lock, flags);
 230        updated = 0;
 231        if (cp->update_flags & CON_UPDATE_ALL) {
 232                con3270_rebuild_update(cp);
 233                con3270_update_status(cp);
 234                cp->update_flags = CON_UPDATE_ERASE | CON_UPDATE_LIST |
 235                        CON_UPDATE_STATUS;
 236        }
 237        if (cp->update_flags & CON_UPDATE_ERASE) {
 238                /* Use erase write alternate to initialize display. */
 239                raw3270_request_set_cmd(wrq, TC_EWRITEA);
 240                updated |= CON_UPDATE_ERASE;
 241        } else
 242                raw3270_request_set_cmd(wrq, TC_WRITE);
 243
 244        wcc = TW_NONE;
 245        raw3270_request_add_data(wrq, &wcc, 1);
 246
 247        /*
 248         * Update status line.
 249         */
 250        if (cp->update_flags & CON_UPDATE_STATUS)
 251                if (raw3270_request_add_data(wrq, cp->status->string,
 252                                             cp->status->len) == 0)
 253                        updated |= CON_UPDATE_STATUS;
 254
 255        if (cp->update_flags & CON_UPDATE_LIST) {
 256                prolog[0] = TO_SBA;
 257                prolog[3] = TO_SA;
 258                prolog[4] = TAT_COLOR;
 259                prolog[5] = TAC_TURQ;
 260                raw3270_buffer_address(cp->view.dev, prolog + 1,
 261                                       cp->view.cols * cp->line_nr);
 262                raw3270_request_add_data(wrq, prolog, 6);
 263                /* Write strings in the update list to the screen. */
 264                list_for_each_entry_safe(s, n, &cp->update, update) {
 265                        if (s != cp->cline)
 266                                con3270_update_string(cp, s, cp->line_nr);
 267                        if (raw3270_request_add_data(wrq, s->string,
 268                                                     s->len) != 0)
 269                                break;
 270                        list_del_init(&s->update);
 271                        if (s != cp->cline)
 272                                cp->line_nr++;
 273                }
 274                if (list_empty(&cp->update))
 275                        updated |= CON_UPDATE_LIST;
 276        }
 277        wrq->callback = con3270_write_callback;
 278        rc = raw3270_start(&cp->view, wrq);
 279        if (rc == 0) {
 280                cp->update_flags &= ~updated;
 281                if (cp->update_flags)
 282                        con3270_set_timer(cp, 1);
 283        } else {
 284                raw3270_request_reset(wrq);
 285                xchg(&cp->write, wrq);
 286        }
 287        spin_unlock_irqrestore(&cp->view.lock, flags);
 288}
 289
 290/*
 291 * Read tasklet.
 292 */
 293static void
 294con3270_read_tasklet(struct raw3270_request *rrq)
 295{
 296        static char kreset_data = TW_KR;
 297        struct con3270 *cp;
 298        unsigned long flags;
 299        int nr_up, deactivate;
 300
 301        cp = (struct con3270 *) rrq->view;
 302        spin_lock_irqsave(&cp->view.lock, flags);
 303        nr_up = cp->nr_up;
 304        deactivate = 0;
 305        /* Check aid byte. */
 306        switch (cp->input->string[0]) {
 307        case 0x7d:      /* enter: jump to bottom. */
 308                nr_up = 0;
 309                break;
 310        case 0xf3:      /* PF3: deactivate the console view. */
 311                deactivate = 1;
 312                break;
 313        case 0x6d:      /* clear: start from scratch. */
 314                cp->update_flags = CON_UPDATE_ALL;
 315                con3270_set_timer(cp, 1);
 316                break;
 317        case 0xf7:      /* PF7: do a page up in the console log. */
 318                nr_up += cp->view.rows - 2;
 319                if (nr_up + cp->view.rows - 1 > cp->nr_lines) {
 320                        nr_up = cp->nr_lines - cp->view.rows + 1;
 321                        if (nr_up < 0)
 322                                nr_up = 0;
 323                }
 324                break;
 325        case 0xf8:      /* PF8: do a page down in the console log. */
 326                nr_up -= cp->view.rows - 2;
 327                if (nr_up < 0)
 328                        nr_up = 0;
 329                break;
 330        }
 331        if (nr_up != cp->nr_up) {
 332                cp->nr_up = nr_up;
 333                con3270_rebuild_update(cp);
 334                con3270_update_status(cp);
 335                con3270_set_timer(cp, 1);
 336        }
 337        spin_unlock_irqrestore(&cp->view.lock, flags);
 338
 339        /* Start keyboard reset command. */
 340        raw3270_request_reset(cp->kreset);
 341        raw3270_request_set_cmd(cp->kreset, TC_WRITE);
 342        raw3270_request_add_data(cp->kreset, &kreset_data, 1);
 343        raw3270_start(&cp->view, cp->kreset);
 344
 345        if (deactivate)
 346                raw3270_deactivate_view(&cp->view);
 347
 348        raw3270_request_reset(rrq);
 349        xchg(&cp->read, rrq);
 350        raw3270_put_view(&cp->view);
 351}
 352
 353/*
 354 * Read request completion callback.
 355 */
 356static void
 357con3270_read_callback(struct raw3270_request *rq, void *data)
 358{
 359        raw3270_get_view(rq->view);
 360        /* Schedule tasklet to pass input to tty. */
 361        tasklet_schedule(&((struct con3270 *) rq->view)->readlet);
 362}
 363
 364/*
 365 * Issue a read request. Called only from interrupt function.
 366 */
 367static void
 368con3270_issue_read(struct con3270 *cp)
 369{
 370        struct raw3270_request *rrq;
 371        int rc;
 372
 373        rrq = xchg(&cp->read, 0);
 374        if (!rrq)
 375                /* Read already scheduled. */
 376                return;
 377        rrq->callback = con3270_read_callback;
 378        rrq->callback_data = cp;
 379        raw3270_request_set_cmd(rrq, TC_READMOD);
 380        raw3270_request_set_data(rrq, cp->input->string, cp->input->len);
 381        /* Issue the read modified request. */
 382        rc = raw3270_start_irq(&cp->view, rrq);
 383        if (rc)
 384                raw3270_request_reset(rrq);
 385}
 386
 387/*
 388 * Switch to the console view.
 389 */
 390static int
 391con3270_activate(struct raw3270_view *view)
 392{
 393        struct con3270 *cp;
 394
 395        cp = (struct con3270 *) view;
 396        cp->update_flags = CON_UPDATE_ALL;
 397        con3270_set_timer(cp, 1);
 398        return 0;
 399}
 400
 401static void
 402con3270_deactivate(struct raw3270_view *view)
 403{
 404        struct con3270 *cp;
 405
 406        cp = (struct con3270 *) view;
 407        del_timer(&cp->timer);
 408}
 409
 410static void
 411con3270_irq(struct con3270 *cp, struct raw3270_request *rq, struct irb *irb)
 412{
 413        /* Handle ATTN. Schedule tasklet to read aid. */
 414        if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION)
 415                con3270_issue_read(cp);
 416
 417        if (rq) {
 418                if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)
 419                        rq->rc = -EIO;
 420                else
 421                        /* Normal end. Copy residual count. */
 422                        rq->rescnt = irb->scsw.cmd.count;
 423        } else if (irb->scsw.cmd.dstat & DEV_STAT_DEV_END) {
 424                /* Interrupt without an outstanding request -> update all */
 425                cp->update_flags = CON_UPDATE_ALL;
 426                con3270_set_timer(cp, 1);
 427        }
 428}
 429
 430/* Console view to a 3270 device. */
 431static struct raw3270_fn con3270_fn = {
 432        .activate = con3270_activate,
 433        .deactivate = con3270_deactivate,
 434        .intv = (void *) con3270_irq
 435};
 436
 437static inline void
 438con3270_cline_add(struct con3270 *cp)
 439{
 440        if (!list_empty(&cp->cline->list))
 441                /* Already added. */
 442                return;
 443        list_add_tail(&cp->cline->list, &cp->lines);
 444        cp->nr_lines++;
 445        con3270_rebuild_update(cp);
 446}
 447
 448static inline void
 449con3270_cline_insert(struct con3270 *cp, unsigned char c)
 450{
 451        cp->cline->string[cp->cline->len++] = 
 452                cp->view.ascebc[(c < ' ') ? ' ' : c];
 453        if (list_empty(&cp->cline->update)) {
 454                list_add_tail(&cp->cline->update, &cp->update);
 455                cp->update_flags |= CON_UPDATE_LIST;
 456        }
 457}
 458
 459static inline void
 460con3270_cline_end(struct con3270 *cp)
 461{
 462        struct string *s;
 463        unsigned int size;
 464
 465        /* Copy cline. */
 466        size = (cp->cline->len < cp->view.cols - 5) ?
 467                cp->cline->len + 4 : cp->view.cols;
 468        s = con3270_alloc_string(cp, size);
 469        memcpy(s->string, cp->cline->string, cp->cline->len);
 470        if (cp->cline->len < cp->view.cols - 5) {
 471                s->string[s->len - 4] = TO_RA;
 472                s->string[s->len - 1] = 0;
 473        } else {
 474                while (--size >= cp->cline->len)
 475                        s->string[size] = cp->view.ascebc[' '];
 476        }
 477        /* Replace cline with allocated line s and reset cline. */
 478        list_add(&s->list, &cp->cline->list);
 479        list_del_init(&cp->cline->list);
 480        if (!list_empty(&cp->cline->update)) {
 481                list_add(&s->update, &cp->cline->update);
 482                list_del_init(&cp->cline->update);
 483        }
 484        cp->cline->len = 0;
 485}
 486
 487/*
 488 * Write a string to the 3270 console
 489 */
 490static void
 491con3270_write(struct console *co, const char *str, unsigned int count)
 492{
 493        struct con3270 *cp;
 494        unsigned long flags;
 495        unsigned char c;
 496
 497        cp = condev;
 498        spin_lock_irqsave(&cp->view.lock, flags);
 499        while (count-- > 0) {
 500                c = *str++;
 501                if (cp->cline->len == 0)
 502                        con3270_cline_add(cp);
 503                if (c != '\n')
 504                        con3270_cline_insert(cp, c);
 505                if (c == '\n' || cp->cline->len >= cp->view.cols)
 506                        con3270_cline_end(cp);
 507        }
 508        /* Setup timer to output current console buffer after 1/10 second */
 509        cp->nr_up = 0;
 510        if (cp->view.dev && !timer_pending(&cp->timer))
 511                con3270_set_timer(cp, HZ/10);
 512        spin_unlock_irqrestore(&cp->view.lock,flags);
 513}
 514
 515static struct tty_driver *
 516con3270_device(struct console *c, int *index)
 517{
 518        *index = c->index;
 519        return tty3270_driver;
 520}
 521
 522/*
 523 * Wait for end of write request.
 524 */
 525static void
 526con3270_wait_write(struct con3270 *cp)
 527{
 528        while (!cp->write) {
 529                raw3270_wait_cons_dev(cp->view.dev);
 530                barrier();
 531        }
 532}
 533
 534/*
 535 * panic() calls con3270_flush through a panic_notifier
 536 * before the system enters a disabled, endless loop.
 537 */
 538static void
 539con3270_flush(void)
 540{
 541        struct con3270 *cp;
 542        unsigned long flags;
 543
 544        cp = condev;
 545        if (!cp->view.dev)
 546                return;
 547        raw3270_activate_view(&cp->view);
 548        spin_lock_irqsave(&cp->view.lock, flags);
 549        con3270_wait_write(cp);
 550        cp->nr_up = 0;
 551        con3270_rebuild_update(cp);
 552        con3270_update_status(cp);
 553        while (cp->update_flags != 0) {
 554                spin_unlock_irqrestore(&cp->view.lock, flags);
 555                con3270_update(&cp->timer);
 556                spin_lock_irqsave(&cp->view.lock, flags);
 557                con3270_wait_write(cp);
 558        }
 559        spin_unlock_irqrestore(&cp->view.lock, flags);
 560}
 561
 562static int con3270_notify(struct notifier_block *self,
 563                          unsigned long event, void *data)
 564{
 565        con3270_flush();
 566        return NOTIFY_OK;
 567}
 568
 569static struct notifier_block on_panic_nb = {
 570        .notifier_call = con3270_notify,
 571        .priority = 0,
 572};
 573
 574static struct notifier_block on_reboot_nb = {
 575        .notifier_call = con3270_notify,
 576        .priority = 0,
 577};
 578
 579/*
 580 *  The console structure for the 3270 console
 581 */
 582static struct console con3270 = {
 583        .name    = "tty3270",
 584        .write   = con3270_write,
 585        .device  = con3270_device,
 586        .flags   = CON_PRINTBUFFER,
 587};
 588
 589/*
 590 * 3270 console initialization code called from console_init().
 591 */
 592static int __init
 593con3270_init(void)
 594{
 595        struct raw3270 *rp;
 596        void *cbuf;
 597        int i;
 598
 599        /* Check if 3270 is to be the console */
 600        if (!CONSOLE_IS_3270)
 601                return -ENODEV;
 602
 603        /* Set the console mode for VM */
 604        if (MACHINE_IS_VM) {
 605                cpcmd("TERM CONMODE 3270", NULL, 0, NULL);
 606                cpcmd("TERM AUTOCR OFF", NULL, 0, NULL);
 607        }
 608
 609        rp = raw3270_setup_console();
 610        if (IS_ERR(rp))
 611                return PTR_ERR(rp);
 612
 613        condev = kzalloc(sizeof(struct con3270), GFP_KERNEL | GFP_DMA);
 614        if (!condev)
 615                return -ENOMEM;
 616        condev->view.dev = rp;
 617
 618        condev->read = raw3270_request_alloc(0);
 619        condev->read->callback = con3270_read_callback;
 620        condev->read->callback_data = condev;
 621        condev->write = raw3270_request_alloc(CON3270_OUTPUT_BUFFER_SIZE);
 622        condev->kreset = raw3270_request_alloc(1);
 623
 624        INIT_LIST_HEAD(&condev->lines);
 625        INIT_LIST_HEAD(&condev->update);
 626        timer_setup(&condev->timer, con3270_update, 0);
 627        tasklet_init(&condev->readlet, 
 628                     (void (*)(unsigned long)) con3270_read_tasklet,
 629                     (unsigned long) condev->read);
 630
 631        raw3270_add_view(&condev->view, &con3270_fn, 1, RAW3270_VIEW_LOCK_IRQ);
 632
 633        INIT_LIST_HEAD(&condev->freemem);
 634        for (i = 0; i < CON3270_STRING_PAGES; i++) {
 635                cbuf = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
 636                add_string_memory(&condev->freemem, cbuf, PAGE_SIZE);
 637        }
 638        condev->cline = alloc_string(&condev->freemem, condev->view.cols);
 639        condev->cline->len = 0;
 640        con3270_create_status(condev);
 641        condev->input = alloc_string(&condev->freemem, 80);
 642        atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
 643        register_reboot_notifier(&on_reboot_nb);
 644        register_console(&con3270);
 645        return 0;
 646}
 647
 648console_initcall(con3270_init);
 649