1dbddf429SAlex Dewar // SPDX-License-Identifier: GPL-2.0
21da177e4SLinus Torvalds /*
363920f47SJeff Dike * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
41da177e4SLinus Torvalds */
51da177e4SLinus Torvalds
663920f47SJeff Dike #include <linux/slab.h>
763920f47SJeff Dike #include <linux/completion.h>
863920f47SJeff Dike #include <linux/irqreturn.h>
963920f47SJeff Dike #include <asm/irq.h>
1037185b33SAl Viro #include <irq_kern.h>
1137185b33SAl Viro #include <os.h>
12*ab7ca2ebSNick Desaulniers #include "xterm.h"
131da177e4SLinus Torvalds
141da177e4SLinus Torvalds struct xterm_wait {
151da177e4SLinus Torvalds struct completion ready;
161da177e4SLinus Torvalds int fd;
171da177e4SLinus Torvalds int pid;
181da177e4SLinus Torvalds int new_fd;
191da177e4SLinus Torvalds };
201da177e4SLinus Torvalds
xterm_interrupt(int irq,void * data)217bea96fdSAl Viro static irqreturn_t xterm_interrupt(int irq, void *data)
221da177e4SLinus Torvalds {
231da177e4SLinus Torvalds struct xterm_wait *xterm = data;
241da177e4SLinus Torvalds int fd;
251da177e4SLinus Torvalds
261da177e4SLinus Torvalds fd = os_rcv_fd(xterm->fd, &xterm->pid);
271da177e4SLinus Torvalds if (fd == -EAGAIN)
2863920f47SJeff Dike return IRQ_NONE;
291da177e4SLinus Torvalds
301da177e4SLinus Torvalds xterm->new_fd = fd;
311da177e4SLinus Torvalds complete(&xterm->ready);
3263920f47SJeff Dike
3363920f47SJeff Dike return IRQ_HANDLED;
341da177e4SLinus Torvalds }
351da177e4SLinus Torvalds
xterm_fd(int socket,int * pid_out)361da177e4SLinus Torvalds int xterm_fd(int socket, int *pid_out)
371da177e4SLinus Torvalds {
381da177e4SLinus Torvalds struct xterm_wait *data;
391da177e4SLinus Torvalds int err, ret;
401da177e4SLinus Torvalds
411da177e4SLinus Torvalds data = kmalloc(sizeof(*data), GFP_KERNEL);
421da177e4SLinus Torvalds if (data == NULL) {
431da177e4SLinus Torvalds printk(KERN_ERR "xterm_fd : failed to allocate xterm_wait\n");
4463920f47SJeff Dike return -ENOMEM;
451da177e4SLinus Torvalds }
461da177e4SLinus Torvalds
471da177e4SLinus Torvalds /* This is a locked semaphore... */
4863920f47SJeff Dike *data = ((struct xterm_wait) { .fd = socket,
491da177e4SLinus Torvalds .pid = -1,
501da177e4SLinus Torvalds .new_fd = -1 });
511da177e4SLinus Torvalds init_completion(&data->ready);
521da177e4SLinus Torvalds
531da177e4SLinus Torvalds err = um_request_irq(XTERM_IRQ, socket, IRQ_READ, xterm_interrupt,
54aab94460STheodore Ts'o IRQF_SHARED, "xterm", data);
5536d46a59SJohannes Berg if (err < 0) {
561da177e4SLinus Torvalds printk(KERN_ERR "xterm_fd : failed to get IRQ for xterm, "
571da177e4SLinus Torvalds "err = %d\n", err);
581da177e4SLinus Torvalds ret = err;
591da177e4SLinus Torvalds goto out;
601da177e4SLinus Torvalds }
611da177e4SLinus Torvalds
621da177e4SLinus Torvalds /* ... so here we wait for an xterm interrupt.
631da177e4SLinus Torvalds *
641da177e4SLinus Torvalds * XXX Note, if the xterm doesn't work for some reason (eg. DISPLAY
651da177e4SLinus Torvalds * isn't set) this will hang... */
661da177e4SLinus Torvalds wait_for_completion(&data->ready);
671da177e4SLinus Torvalds
68fa7a0449SRichard Weinberger um_free_irq(XTERM_IRQ, data);
691da177e4SLinus Torvalds
701da177e4SLinus Torvalds ret = data->new_fd;
711da177e4SLinus Torvalds *pid_out = data->pid;
721da177e4SLinus Torvalds out:
731da177e4SLinus Torvalds kfree(data);
741da177e4SLinus Torvalds
7563920f47SJeff Dike return ret;
761da177e4SLinus Torvalds }
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