![Martin Schwidefsky](/assets/img/avatar_default.png)
Use nonseekable_open for a couple of s390 device drivers. This avoids the use of default_llseek function which has a dependency on the BKL. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
550 lines
12 KiB
C
550 lines
12 KiB
C
/*
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* IBM/3270 Driver - fullscreen driver.
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*
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* Author(s):
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* Original 3270 Code for 2.4 written by Richard Hitt (UTS Global)
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* Rewritten for 2.5/2.6 by Martin Schwidefsky <schwidefsky@de.ibm.com>
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* Copyright IBM Corp. 2003, 2009
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*/
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#include <linux/bootmem.h>
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#include <linux/console.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/list.h>
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#include <linux/slab.h>
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#include <linux/types.h>
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#include <linux/smp_lock.h>
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#include <asm/compat.h>
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#include <asm/ccwdev.h>
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#include <asm/cio.h>
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#include <asm/ebcdic.h>
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#include <asm/idals.h>
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#include "raw3270.h"
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#include "ctrlchar.h"
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static struct raw3270_fn fs3270_fn;
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struct fs3270 {
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struct raw3270_view view;
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struct pid *fs_pid; /* Pid of controlling program. */
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int read_command; /* ccw command to use for reads. */
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int write_command; /* ccw command to use for writes. */
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int attention; /* Got attention. */
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int active; /* Fullscreen view is active. */
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struct raw3270_request *init; /* single init request. */
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wait_queue_head_t wait; /* Init & attention wait queue. */
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struct idal_buffer *rdbuf; /* full-screen-deactivate buffer */
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size_t rdbuf_size; /* size of data returned by RDBUF */
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};
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static DEFINE_MUTEX(fs3270_mutex);
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static void
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fs3270_wake_up(struct raw3270_request *rq, void *data)
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{
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wake_up((wait_queue_head_t *) data);
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}
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static inline int
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fs3270_working(struct fs3270 *fp)
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{
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/*
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* The fullscreen view is in working order if the view
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* has been activated AND the initial request is finished.
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*/
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return fp->active && raw3270_request_final(fp->init);
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}
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static int
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fs3270_do_io(struct raw3270_view *view, struct raw3270_request *rq)
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{
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struct fs3270 *fp;
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int rc;
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fp = (struct fs3270 *) view;
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rq->callback = fs3270_wake_up;
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rq->callback_data = &fp->wait;
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do {
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if (!fs3270_working(fp)) {
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/* Fullscreen view isn't ready yet. */
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rc = wait_event_interruptible(fp->wait,
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fs3270_working(fp));
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if (rc != 0)
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break;
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}
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rc = raw3270_start(view, rq);
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if (rc == 0) {
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/* Started successfully. Now wait for completion. */
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wait_event(fp->wait, raw3270_request_final(rq));
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}
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} while (rc == -EACCES);
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return rc;
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}
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/*
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* Switch to the fullscreen view.
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*/
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static void
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fs3270_reset_callback(struct raw3270_request *rq, void *data)
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{
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struct fs3270 *fp;
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fp = (struct fs3270 *) rq->view;
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raw3270_request_reset(rq);
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wake_up(&fp->wait);
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}
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static void
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fs3270_restore_callback(struct raw3270_request *rq, void *data)
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{
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struct fs3270 *fp;
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fp = (struct fs3270 *) rq->view;
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if (rq->rc != 0 || rq->rescnt != 0) {
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if (fp->fs_pid)
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kill_pid(fp->fs_pid, SIGHUP, 1);
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}
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fp->rdbuf_size = 0;
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raw3270_request_reset(rq);
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wake_up(&fp->wait);
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}
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static int
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fs3270_activate(struct raw3270_view *view)
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{
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struct fs3270 *fp;
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char *cp;
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int rc;
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fp = (struct fs3270 *) view;
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/* If an old init command is still running just return. */
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if (!raw3270_request_final(fp->init))
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return 0;
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if (fp->rdbuf_size == 0) {
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/* No saved buffer. Just clear the screen. */
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raw3270_request_set_cmd(fp->init, TC_EWRITEA);
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fp->init->callback = fs3270_reset_callback;
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} else {
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/* Restore fullscreen buffer saved by fs3270_deactivate. */
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raw3270_request_set_cmd(fp->init, TC_EWRITEA);
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raw3270_request_set_idal(fp->init, fp->rdbuf);
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fp->init->ccw.count = fp->rdbuf_size;
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cp = fp->rdbuf->data[0];
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cp[0] = TW_KR;
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cp[1] = TO_SBA;
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cp[2] = cp[6];
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cp[3] = cp[7];
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cp[4] = TO_IC;
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cp[5] = TO_SBA;
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cp[6] = 0x40;
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cp[7] = 0x40;
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fp->init->rescnt = 0;
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fp->init->callback = fs3270_restore_callback;
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}
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rc = fp->init->rc = raw3270_start_locked(view, fp->init);
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if (rc)
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fp->init->callback(fp->init, NULL);
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else
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fp->active = 1;
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return rc;
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}
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/*
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* Shutdown fullscreen view.
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*/
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static void
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fs3270_save_callback(struct raw3270_request *rq, void *data)
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{
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struct fs3270 *fp;
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fp = (struct fs3270 *) rq->view;
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/* Correct idal buffer element 0 address. */
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fp->rdbuf->data[0] -= 5;
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fp->rdbuf->size += 5;
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/*
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* If the rdbuf command failed or the idal buffer is
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* to small for the amount of data returned by the
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* rdbuf command, then we have no choice but to send
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* a SIGHUP to the application.
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*/
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if (rq->rc != 0 || rq->rescnt == 0) {
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if (fp->fs_pid)
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kill_pid(fp->fs_pid, SIGHUP, 1);
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fp->rdbuf_size = 0;
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} else
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fp->rdbuf_size = fp->rdbuf->size - rq->rescnt;
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raw3270_request_reset(rq);
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wake_up(&fp->wait);
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}
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static void
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fs3270_deactivate(struct raw3270_view *view)
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{
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struct fs3270 *fp;
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fp = (struct fs3270 *) view;
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fp->active = 0;
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/* If an old init command is still running just return. */
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if (!raw3270_request_final(fp->init))
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return;
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/* Prepare read-buffer request. */
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raw3270_request_set_cmd(fp->init, TC_RDBUF);
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/*
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* Hackish: skip first 5 bytes of the idal buffer to make
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* room for the TW_KR/TO_SBA/<address>/<address>/TO_IC sequence
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* in the activation command.
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*/
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fp->rdbuf->data[0] += 5;
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fp->rdbuf->size -= 5;
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raw3270_request_set_idal(fp->init, fp->rdbuf);
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fp->init->rescnt = 0;
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fp->init->callback = fs3270_save_callback;
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/* Start I/O to read in the 3270 buffer. */
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fp->init->rc = raw3270_start_locked(view, fp->init);
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if (fp->init->rc)
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fp->init->callback(fp->init, NULL);
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}
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static int
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fs3270_irq(struct fs3270 *fp, struct raw3270_request *rq, struct irb *irb)
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{
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/* Handle ATTN. Set indication and wake waiters for attention. */
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if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
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fp->attention = 1;
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wake_up(&fp->wait);
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}
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if (rq) {
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if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)
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rq->rc = -EIO;
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else
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/* Normal end. Copy residual count. */
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rq->rescnt = irb->scsw.cmd.count;
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}
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return RAW3270_IO_DONE;
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}
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/*
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* Process reads from fullscreen 3270.
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*/
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static ssize_t
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fs3270_read(struct file *filp, char __user *data, size_t count, loff_t *off)
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{
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struct fs3270 *fp;
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struct raw3270_request *rq;
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struct idal_buffer *ib;
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ssize_t rc;
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if (count == 0 || count > 65535)
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return -EINVAL;
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fp = filp->private_data;
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if (!fp)
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return -ENODEV;
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ib = idal_buffer_alloc(count, 0);
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if (IS_ERR(ib))
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return -ENOMEM;
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rq = raw3270_request_alloc(0);
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if (!IS_ERR(rq)) {
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if (fp->read_command == 0 && fp->write_command != 0)
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fp->read_command = 6;
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raw3270_request_set_cmd(rq, fp->read_command ? : 2);
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raw3270_request_set_idal(rq, ib);
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rc = wait_event_interruptible(fp->wait, fp->attention);
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fp->attention = 0;
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if (rc == 0) {
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rc = fs3270_do_io(&fp->view, rq);
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if (rc == 0) {
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count -= rq->rescnt;
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if (idal_buffer_to_user(ib, data, count) != 0)
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rc = -EFAULT;
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else
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rc = count;
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}
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}
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raw3270_request_free(rq);
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} else
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rc = PTR_ERR(rq);
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idal_buffer_free(ib);
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return rc;
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}
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/*
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* Process writes to fullscreen 3270.
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*/
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static ssize_t
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fs3270_write(struct file *filp, const char __user *data, size_t count, loff_t *off)
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{
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struct fs3270 *fp;
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struct raw3270_request *rq;
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struct idal_buffer *ib;
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int write_command;
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ssize_t rc;
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fp = filp->private_data;
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if (!fp)
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return -ENODEV;
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ib = idal_buffer_alloc(count, 0);
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if (IS_ERR(ib))
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return -ENOMEM;
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rq = raw3270_request_alloc(0);
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if (!IS_ERR(rq)) {
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if (idal_buffer_from_user(ib, data, count) == 0) {
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write_command = fp->write_command ? : 1;
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if (write_command == 5)
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write_command = 13;
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raw3270_request_set_cmd(rq, write_command);
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raw3270_request_set_idal(rq, ib);
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rc = fs3270_do_io(&fp->view, rq);
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if (rc == 0)
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rc = count - rq->rescnt;
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} else
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rc = -EFAULT;
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raw3270_request_free(rq);
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} else
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rc = PTR_ERR(rq);
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idal_buffer_free(ib);
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return rc;
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}
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/*
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* process ioctl commands for the tube driver
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*/
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static long
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fs3270_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
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{
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char __user *argp;
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struct fs3270 *fp;
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struct raw3270_iocb iocb;
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int rc;
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fp = filp->private_data;
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if (!fp)
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return -ENODEV;
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if (is_compat_task())
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argp = compat_ptr(arg);
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else
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argp = (char __user *)arg;
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rc = 0;
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mutex_lock(&fs3270_mutex);
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switch (cmd) {
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case TUBICMD:
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fp->read_command = arg;
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break;
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case TUBOCMD:
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fp->write_command = arg;
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break;
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case TUBGETI:
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rc = put_user(fp->read_command, argp);
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break;
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case TUBGETO:
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rc = put_user(fp->write_command, argp);
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break;
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case TUBGETMOD:
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iocb.model = fp->view.model;
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iocb.line_cnt = fp->view.rows;
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iocb.col_cnt = fp->view.cols;
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iocb.pf_cnt = 24;
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iocb.re_cnt = 20;
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iocb.map = 0;
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if (copy_to_user(argp, &iocb, sizeof(struct raw3270_iocb)))
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rc = -EFAULT;
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break;
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}
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mutex_unlock(&fs3270_mutex);
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return rc;
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}
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/*
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* Allocate fs3270 structure.
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*/
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static struct fs3270 *
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fs3270_alloc_view(void)
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{
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struct fs3270 *fp;
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fp = kzalloc(sizeof(struct fs3270),GFP_KERNEL);
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if (!fp)
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return ERR_PTR(-ENOMEM);
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fp->init = raw3270_request_alloc(0);
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if (IS_ERR(fp->init)) {
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kfree(fp);
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return ERR_PTR(-ENOMEM);
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}
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return fp;
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}
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/*
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* Free fs3270 structure.
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*/
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static void
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fs3270_free_view(struct raw3270_view *view)
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{
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struct fs3270 *fp;
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fp = (struct fs3270 *) view;
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if (fp->rdbuf)
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idal_buffer_free(fp->rdbuf);
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raw3270_request_free(((struct fs3270 *) view)->init);
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kfree(view);
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}
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/*
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* Unlink fs3270 data structure from filp.
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*/
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static void
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fs3270_release(struct raw3270_view *view)
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{
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struct fs3270 *fp;
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fp = (struct fs3270 *) view;
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if (fp->fs_pid)
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kill_pid(fp->fs_pid, SIGHUP, 1);
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}
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/* View to a 3270 device. Can be console, tty or fullscreen. */
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static struct raw3270_fn fs3270_fn = {
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.activate = fs3270_activate,
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.deactivate = fs3270_deactivate,
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.intv = (void *) fs3270_irq,
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.release = fs3270_release,
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.free = fs3270_free_view
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};
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/*
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* This routine is called whenever a 3270 fullscreen device is opened.
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*/
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static int
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fs3270_open(struct inode *inode, struct file *filp)
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{
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struct fs3270 *fp;
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struct idal_buffer *ib;
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int minor, rc = 0;
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if (imajor(filp->f_path.dentry->d_inode) != IBM_FS3270_MAJOR)
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return -ENODEV;
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minor = iminor(filp->f_path.dentry->d_inode);
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/* Check for minor 0 multiplexer. */
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if (minor == 0) {
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struct tty_struct *tty = get_current_tty();
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if (!tty || tty->driver->major != IBM_TTY3270_MAJOR) {
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tty_kref_put(tty);
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return -ENODEV;
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}
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minor = tty->index + RAW3270_FIRSTMINOR;
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tty_kref_put(tty);
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}
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mutex_lock(&fs3270_mutex);
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/* Check if some other program is already using fullscreen mode. */
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fp = (struct fs3270 *) raw3270_find_view(&fs3270_fn, minor);
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if (!IS_ERR(fp)) {
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raw3270_put_view(&fp->view);
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rc = -EBUSY;
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goto out;
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}
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/* Allocate fullscreen view structure. */
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fp = fs3270_alloc_view();
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if (IS_ERR(fp)) {
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rc = PTR_ERR(fp);
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goto out;
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}
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init_waitqueue_head(&fp->wait);
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fp->fs_pid = get_pid(task_pid(current));
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rc = raw3270_add_view(&fp->view, &fs3270_fn, minor);
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if (rc) {
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fs3270_free_view(&fp->view);
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goto out;
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}
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/* Allocate idal-buffer. */
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ib = idal_buffer_alloc(2*fp->view.rows*fp->view.cols + 5, 0);
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if (IS_ERR(ib)) {
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raw3270_put_view(&fp->view);
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raw3270_del_view(&fp->view);
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rc = PTR_ERR(ib);
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goto out;
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}
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fp->rdbuf = ib;
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rc = raw3270_activate_view(&fp->view);
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if (rc) {
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raw3270_put_view(&fp->view);
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raw3270_del_view(&fp->view);
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goto out;
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}
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nonseekable_open(inode, filp);
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filp->private_data = fp;
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out:
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mutex_unlock(&fs3270_mutex);
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return rc;
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}
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/*
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* This routine is called when the 3270 tty is closed. We wait
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* for the remaining request to be completed. Then we clean up.
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*/
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static int
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fs3270_close(struct inode *inode, struct file *filp)
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{
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struct fs3270 *fp;
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fp = filp->private_data;
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filp->private_data = NULL;
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if (fp) {
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put_pid(fp->fs_pid);
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fp->fs_pid = NULL;
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raw3270_reset(&fp->view);
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raw3270_put_view(&fp->view);
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raw3270_del_view(&fp->view);
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}
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return 0;
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}
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static const struct file_operations fs3270_fops = {
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.owner = THIS_MODULE, /* owner */
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.read = fs3270_read, /* read */
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.write = fs3270_write, /* write */
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.unlocked_ioctl = fs3270_ioctl, /* ioctl */
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.compat_ioctl = fs3270_ioctl, /* ioctl */
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.open = fs3270_open, /* open */
|
|
.release = fs3270_close, /* release */
|
|
};
|
|
|
|
/*
|
|
* 3270 fullscreen driver initialization.
|
|
*/
|
|
static int __init
|
|
fs3270_init(void)
|
|
{
|
|
int rc;
|
|
|
|
rc = register_chrdev(IBM_FS3270_MAJOR, "fs3270", &fs3270_fops);
|
|
if (rc)
|
|
return rc;
|
|
return 0;
|
|
}
|
|
|
|
static void __exit
|
|
fs3270_exit(void)
|
|
{
|
|
unregister_chrdev(IBM_FS3270_MAJOR, "fs3270");
|
|
}
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS_CHARDEV_MAJOR(IBM_FS3270_MAJOR);
|
|
|
|
module_init(fs3270_init);
|
|
module_exit(fs3270_exit);
|