con3270.c

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/*
 * IBM/3270 Driver - console view.
 *
 * Author(s):
 *   Original 3270 Code for 2.4 written by Richard Hitt (UTS Global)
 *   Rewritten for 2.5 by Martin Schwidefsky <[email protected]>
 *     Copyright IBM Corp. 2003, 2009
 */

#include <linux/console.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/reboot.h>

#include <asm/ccwdev.h>
#include <asm/cio.h>
#include <asm/cpcmd.h>
#include <asm/ebcdic.h>

#include "raw3270.h"
#include "tty3270.h"
#include "ctrlchar.h"

#define CON3270_OUTPUT_BUFFER_SIZE 1024
#define CON3270_STRING_PAGES 4

static struct raw3270_fn con3270_fn;

/*
 * Main 3270 console view data structure.
 */
struct con3270 {
    struct raw3270_view view;
    struct list_head freemem;   /* list of free memory for strings. */

    /* Output stuff. */
    struct list_head lines;     /* list of lines. */
    struct list_head update;    /* list of lines to update. */
    int line_nr;            /* line number for next update. */
    int nr_lines;           /* # lines in list. */
    int nr_up;          /* # lines up in history. */
    unsigned long update_flags; /* Update indication bits. */
    struct string *cline;       /* current output line. */
    struct string *status;      /* last line of display. */
    struct raw3270_request *write;  /* single write request. */
    struct timer_list timer;

    /* Input stuff. */
    struct string *input;       /* input string for read request. */
    struct raw3270_request *read;   /* single read request. */
    struct raw3270_request *kreset; /* single keyboard reset request. */
    struct tasklet_struct readlet;  /* tasklet to issue read request. */
};

static struct con3270 *condev;

/* con3270->update_flags. See con3270_update for details. */
#define CON_UPDATE_ERASE    1   /* Use EWRITEA instead of WRITE. */
#define CON_UPDATE_LIST     2   /* Update lines in tty3270->update. */
#define CON_UPDATE_STATUS   4   /* Update status line. */
#define CON_UPDATE_ALL      8   /* Recreate screen. */

static void con3270_update(struct con3270 *);

/*
 * Setup timeout for a device. On timeout trigger an update.
 */
static void con3270_set_timer(struct con3270 *cp, int expires)
{
    if (expires == 0)
        del_timer(&cp->timer);
    else
        mod_timer(&cp->timer, jiffies + expires);
}

/*
 * The status line is the last line of the screen. It shows the string
 * "console view" in the lower left corner and "Running"/"More..."/"Holding"
 * in the lower right corner of the screen.
 */
static void
con3270_update_status(struct con3270 *cp)
{
    char *str;

    str = (cp->nr_up != 0) ? "History" : "Running";
    memcpy(cp->status->string + 24, str, 7);
    codepage_convert(cp->view.ascebc, cp->status->string + 24, 7);
    cp->update_flags |= CON_UPDATE_STATUS;
}

static void
con3270_create_status(struct con3270 *cp)
{
    static const unsigned char blueprint[] =
        { TO_SBA, 0, 0, TO_SF,TF_LOG,TO_SA,TAT_COLOR, TAC_GREEN,
          'c','o','n','s','o','l','e',' ','v','i','e','w',
          TO_RA,0,0,0,'R','u','n','n','i','n','g',TO_SF,TF_LOG };

    cp->status = alloc_string(&cp->freemem, sizeof(blueprint));
    /* Copy blueprint to status line */
    memcpy(cp->status->string, blueprint, sizeof(blueprint));
    /* Set TO_RA addresses. */
    raw3270_buffer_address(cp->view.dev, cp->status->string + 1,
                   cp->view.cols * (cp->view.rows - 1));
    raw3270_buffer_address(cp->view.dev, cp->status->string + 21,
                   cp->view.cols * cp->view.rows - 8);
    /* Convert strings to ebcdic. */
    codepage_convert(cp->view.ascebc, cp->status->string + 8, 12);
    codepage_convert(cp->view.ascebc, cp->status->string + 24, 7);
}

/*
 * Set output offsets to 3270 datastream fragment of a console string.
 */
static void
con3270_update_string(struct con3270 *cp, struct string *s, int nr)
{
    if (s->len >= cp->view.cols - 5)
        return;
    raw3270_buffer_address(cp->view.dev, s->string + s->len - 3,
                   cp->view.cols * (nr + 1));
}

/*
 * Rebuild update list to print all lines.
 */
static void
con3270_rebuild_update(struct con3270 *cp)
{
    struct string *s, *n;
    int nr;

    /* 
     * Throw away update list and create a new one,
     * containing all lines that will fit on the screen.
     */
    list_for_each_entry_safe(s, n, &cp->update, update)
        list_del_init(&s->update);
    nr = cp->view.rows - 2 + cp->nr_up;
    list_for_each_entry_reverse(s, &cp->lines, list) {
        if (nr < cp->view.rows - 1)
            list_add(&s->update, &cp->update);
        if (--nr < 0)
            break;
    }
    cp->line_nr = 0;
    cp->update_flags |= CON_UPDATE_LIST;
}

/*
 * Alloc string for size bytes. Free strings from history if necessary.
 */
static struct string *
con3270_alloc_string(struct con3270 *cp, size_t size)
{
    struct string *s, *n;

    s = alloc_string(&cp->freemem, size);
    if (s)
        return s;
    list_for_each_entry_safe(s, n, &cp->lines, list) {
        list_del(&s->list);
        if (!list_empty(&s->update))
            list_del(&s->update);
        cp->nr_lines--;
        if (free_string(&cp->freemem, s) >= size)
            break;
    }
    s = alloc_string(&cp->freemem, size);
    BUG_ON(!s);
    if (cp->nr_up != 0 && cp->nr_up + cp->view.rows > cp->nr_lines) {
        cp->nr_up = cp->nr_lines - cp->view.rows + 1;
        con3270_rebuild_update(cp);
        con3270_update_status(cp);
    }
    return s;
}

/*
 * Write completion callback.
 */
static void
con3270_write_callback(struct raw3270_request *rq, void *data)
{
    raw3270_request_reset(rq);
    xchg(&((struct con3270 *) rq->view)->write, rq);
}

/*
 * Update console display.
 */
static void
con3270_update(struct con3270 *cp)
{
    struct raw3270_request *wrq;
    char wcc, prolog[6];
    unsigned long flags;
    unsigned long updated;
    struct string *s, *n;
    int rc;

    if (cp->view.dev)
        raw3270_activate_view(&cp->view);

    wrq = xchg(&cp->write, 0);
    if (!wrq) {
        con3270_set_timer(cp, 1);
        return;
    }

    spin_lock_irqsave(&cp->view.lock, flags);
    updated = 0;
    if (cp->update_flags & CON_UPDATE_ALL) {
        con3270_rebuild_update(cp);
        con3270_update_status(cp);
        cp->update_flags = CON_UPDATE_ERASE | CON_UPDATE_LIST |
            CON_UPDATE_STATUS;
    }
    if (cp->update_flags & CON_UPDATE_ERASE) {
        /* Use erase write alternate to initialize display. */
        raw3270_request_set_cmd(wrq, TC_EWRITEA);
        updated |= CON_UPDATE_ERASE;
    } else
        raw3270_request_set_cmd(wrq, TC_WRITE);

    wcc = TW_NONE;
    raw3270_request_add_data(wrq, &wcc, 1);

    /*
     * Update status line.
     */
    if (cp->update_flags & CON_UPDATE_STATUS)
        if (raw3270_request_add_data(wrq, cp->status->string,
                         cp->status->len) == 0)
            updated |= CON_UPDATE_STATUS;

    if (cp->update_flags & CON_UPDATE_LIST) {
        prolog[0] = TO_SBA;
        prolog[3] = TO_SA;
        prolog[4] = TAT_COLOR;
        prolog[5] = TAC_TURQ;
        raw3270_buffer_address(cp->view.dev, prolog + 1,
                       cp->view.cols * cp->line_nr);
        raw3270_request_add_data(wrq, prolog, 6);
        /* Write strings in the update list to the screen. */
        list_for_each_entry_safe(s, n, &cp->update, update) {
            if (s != cp->cline)
                con3270_update_string(cp, s, cp->line_nr);
            if (raw3270_request_add_data(wrq, s->string,
                             s->len) != 0)
                break;
            list_del_init(&s->update);
            if (s != cp->cline)
                cp->line_nr++;
        }
        if (list_empty(&cp->update))
            updated |= CON_UPDATE_LIST;
    }
    wrq->callback = con3270_write_callback;
    rc = raw3270_start(&cp->view, wrq);
    if (rc == 0) {
        cp->update_flags &= ~updated;
        if (cp->update_flags)
            con3270_set_timer(cp, 1);
    } else {
        raw3270_request_reset(wrq);
        xchg(&cp->write, wrq);
    }
    spin_unlock_irqrestore(&cp->view.lock, flags);
}

/*
 * Read tasklet.
 */
static void
con3270_read_tasklet(struct raw3270_request *rrq)
{
    static char kreset_data = TW_KR;
    struct con3270 *cp;
    unsigned long flags;
    int nr_up, deactivate;

    cp = (struct con3270 *) rrq->view;
    spin_lock_irqsave(&cp->view.lock, flags);
    nr_up = cp->nr_up;
    deactivate = 0;
    /* Check aid byte. */
    switch (cp->input->string[0]) {
    case 0x7d:  /* enter: jump to bottom. */
        nr_up = 0;
        break;
    case 0xf3:  /* PF3: deactivate the console view. */
        deactivate = 1;
        break;
    case 0x6d:  /* clear: start from scratch. */
        cp->update_flags = CON_UPDATE_ALL;
        con3270_set_timer(cp, 1);
        break;
    case 0xf7:  /* PF7: do a page up in the console log. */
        nr_up += cp->view.rows - 2;
        if (nr_up + cp->view.rows - 1 > cp->nr_lines) {
            nr_up = cp->nr_lines - cp->view.rows + 1;
            if (nr_up < 0)
                nr_up = 0;
        }
        break;
    case 0xf8:  /* PF8: do a page down in the console log. */
        nr_up -= cp->view.rows - 2;
        if (nr_up < 0)
            nr_up = 0;
        break;
    }
    if (nr_up != cp->nr_up) {
        cp->nr_up = nr_up;
        con3270_rebuild_update(cp);
        con3270_update_status(cp);
        con3270_set_timer(cp, 1);
    }
    spin_unlock_irqrestore(&cp->view.lock, flags);

    /* Start keyboard reset command. */
    raw3270_request_reset(cp->kreset);
    raw3270_request_set_cmd(cp->kreset, TC_WRITE);
    raw3270_request_add_data(cp->kreset, &kreset_data, 1);
    raw3270_start(&cp->view, cp->kreset);

    if (deactivate)
        raw3270_deactivate_view(&cp->view);

    raw3270_request_reset(rrq);
    xchg(&cp->read, rrq);
    raw3270_put_view(&cp->view);
}

/*
 * Read request completion callback.
 */
static void
con3270_read_callback(struct raw3270_request *rq, void *data)
{
    raw3270_get_view(rq->view);
    /* Schedule tasklet to pass input to tty. */
    tasklet_schedule(&((struct con3270 *) rq->view)->readlet);
}

/*
 * Issue a read request. Called only from interrupt function.
 */
static void
con3270_issue_read(struct con3270 *cp)
{
    struct raw3270_request *rrq;
    int rc;

    rrq = xchg(&cp->read, 0);
    if (!rrq)
        /* Read already scheduled. */
        return;
    rrq->callback = con3270_read_callback;
    rrq->callback_data = cp;
    raw3270_request_set_cmd(rrq, TC_READMOD);
    raw3270_request_set_data(rrq, cp->input->string, cp->input->len);
    /* Issue the read modified request. */
    rc = raw3270_start_irq(&cp->view, rrq);
    if (rc)
        raw3270_request_reset(rrq);
}

/*
 * Switch to the console view.
 */
static int
con3270_activate(struct raw3270_view *view)
{
    struct con3270 *cp;

    cp = (struct con3270 *) view;
    cp->update_flags = CON_UPDATE_ALL;
    con3270_set_timer(cp, 1);
    return 0;
}

static void
con3270_deactivate(struct raw3270_view *view)
{
    struct con3270 *cp;

    cp = (struct con3270 *) view;
    del_timer(&cp->timer);
}

static int
con3270_irq(struct con3270 *cp, struct raw3270_request *rq, struct irb *irb)
{
    /* Handle ATTN. Schedule tasklet to read aid. */
    if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION)
        con3270_issue_read(cp);

    if (rq) {
        if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)
            rq->rc = -EIO;
        else
            /* Normal end. Copy residual count. */
            rq->rescnt = irb->scsw.cmd.count;
    }
    return RAW3270_IO_DONE;
}

/* Console view to a 3270 device. */
static struct raw3270_fn con3270_fn = {
    .activate = con3270_activate,
    .deactivate = con3270_deactivate,
    .intv = (void *) con3270_irq
};

static inline void
con3270_cline_add(struct con3270 *cp)
{
    if (!list_empty(&cp->cline->list))
        /* Already added. */
        return;
    list_add_tail(&cp->cline->list, &cp->lines);
    cp->nr_lines++;
    con3270_rebuild_update(cp);
}

static inline void
con3270_cline_insert(struct con3270 *cp, unsigned char c)
{
    cp->cline->string[cp->cline->len++] = 
        cp->view.ascebc[(c < ' ') ? ' ' : c];
    if (list_empty(&cp->cline->update)) {
        list_add_tail(&cp->cline->update, &cp->update);
        cp->update_flags |= CON_UPDATE_LIST;
    }
}

static inline void
con3270_cline_end(struct con3270 *cp)
{
    struct string *s;
    unsigned int size;

    /* Copy cline. */
    size = (cp->cline->len < cp->view.cols - 5) ?
        cp->cline->len + 4 : cp->view.cols;
    s = con3270_alloc_string(cp, size);
    memcpy(s->string, cp->cline->string, cp->cline->len);
    if (s->len < cp->view.cols - 5) {
        s->string[s->len - 4] = TO_RA;
        s->string[s->len - 1] = 0;
    } else {
        while (--size > cp->cline->len)
            s->string[size] = cp->view.ascebc[' '];
    }
    /* Replace cline with allocated line s and reset cline. */
    list_add(&s->list, &cp->cline->list);
    list_del_init(&cp->cline->list);
    if (!list_empty(&cp->cline->update)) {
        list_add(&s->update, &cp->cline->update);
        list_del_init(&cp->cline->update);
    }
    cp->cline->len = 0;
}

/*
 * Write a string to the 3270 console
 */
static void
con3270_write(struct console *co, const char *str, unsigned int count)
{
    struct con3270 *cp;
    unsigned long flags;
    unsigned char c;

    cp = condev;
    spin_lock_irqsave(&cp->view.lock, flags);
    while (count-- > 0) {
        c = *str++;
        if (cp->cline->len == 0)
            con3270_cline_add(cp);
        if (c != '\n')
            con3270_cline_insert(cp, c);
        if (c == '\n' || cp->cline->len >= cp->view.cols)
            con3270_cline_end(cp);
    }
    /* Setup timer to output current console buffer after 1/10 second */
    cp->nr_up = 0;
    if (cp->view.dev && !timer_pending(&cp->timer))
        con3270_set_timer(cp, HZ/10);
    spin_unlock_irqrestore(&cp->view.lock,flags);
}

static struct tty_driver *
con3270_device(struct console *c, int *index)
{
    *index = c->index;
    return tty3270_driver;
}

/*
 * Wait for end of write request.
 */
static void
con3270_wait_write(struct con3270 *cp)
{
    while (!cp->write) {
        raw3270_wait_cons_dev(cp->view.dev);
        barrier();
    }
}

/*
 * panic() calls con3270_flush through a panic_notifier
 * before the system enters a disabled, endless loop.
 */
static void
con3270_flush(void)
{
    struct con3270 *cp;
    unsigned long flags;

    cp = condev;
    if (!cp->view.dev)
        return;
    raw3270_pm_unfreeze(&cp->view);
    spin_lock_irqsave(&cp->view.lock, flags);
    con3270_wait_write(cp);
    cp->nr_up = 0;
    con3270_rebuild_update(cp);
    con3270_update_status(cp);
    while (cp->update_flags != 0) {
        spin_unlock_irqrestore(&cp->view.lock, flags);
        con3270_update(cp);
        spin_lock_irqsave(&cp->view.lock, flags);
        con3270_wait_write(cp);
    }
    spin_unlock_irqrestore(&cp->view.lock, flags);
}

static int con3270_notify(struct notifier_block *self,
              unsigned long event, void *data)
{
    con3270_flush();
    return NOTIFY_OK;
}

static struct notifier_block on_panic_nb = {
    .notifier_call = con3270_notify,
    .priority = 0,
};

static struct notifier_block on_reboot_nb = {
    .notifier_call = con3270_notify,
    .priority = 0,
};

/*
 *  The console structure for the 3270 console
 */
static struct console con3270 = {
    .name    = "tty3270",
    .write   = con3270_write,
    .device  = con3270_device,
    .flags   = CON_PRINTBUFFER,
};

/*
 * 3270 console initialization code called from console_init().
 */
static int __init
con3270_init(void)
{
    struct ccw_device *cdev;
    struct raw3270 *rp;
    void *cbuf;
    int i;

    /* Check if 3270 is to be the console */
    if (!CONSOLE_IS_3270)
        return -ENODEV;

    /* Set the console mode for VM */
    if (MACHINE_IS_VM) {
        cpcmd("TERM CONMODE 3270", NULL, 0, NULL);
        cpcmd("TERM AUTOCR OFF", NULL, 0, NULL);
    }

    cdev = ccw_device_probe_console();
    if (IS_ERR(cdev))
        return -ENODEV;
    rp = raw3270_setup_console(cdev);
    if (IS_ERR(rp))
        return PTR_ERR(rp);

    condev = kzalloc(sizeof(struct con3270), GFP_KERNEL | GFP_DMA);
    condev->view.dev = rp;

    condev->read = raw3270_request_alloc(0);
    condev->read->callback = con3270_read_callback;
    condev->read->callback_data = condev;
    condev->write = raw3270_request_alloc(CON3270_OUTPUT_BUFFER_SIZE);
    condev->kreset = raw3270_request_alloc(1);

    INIT_LIST_HEAD(&condev->lines);
    INIT_LIST_HEAD(&condev->update);
    setup_timer(&condev->timer, (void (*)(unsigned long)) con3270_update,
            (unsigned long) condev);
    tasklet_init(&condev->readlet, 
             (void (*)(unsigned long)) con3270_read_tasklet,
             (unsigned long) condev->read);

    raw3270_add_view(&condev->view, &con3270_fn, 1);

    INIT_LIST_HEAD(&condev->freemem);
    for (i = 0; i < CON3270_STRING_PAGES; i++) {
        cbuf = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
        add_string_memory(&condev->freemem, cbuf, PAGE_SIZE);
    }
    condev->cline = alloc_string(&condev->freemem, condev->view.cols);
    condev->cline->len = 0;
    con3270_create_status(condev);
    condev->input = alloc_string(&condev->freemem, 80);
    atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
    register_reboot_notifier(&on_reboot_nb);
    register_console(&con3270);
    return 0;
}

console_initcall(con3270_init);