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> 12ab7ca2ebSNick 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 217bea96fdSAl Viro static irqreturn_t xterm_interrupt(int irq, void *data) 221da177e4SLinus Torvalds { 231da177e4SLinus Torvalds struct xterm_wait *xterm = data; 24*5cde6096SJohannes Berg int fd = -1, n_fds = 1; 25*5cde6096SJohannes Berg ssize_t ret; 261da177e4SLinus Torvalds 27*5cde6096SJohannes Berg ret = os_rcv_fd_msg(xterm->fd, &fd, n_fds, 28*5cde6096SJohannes Berg &xterm->pid, sizeof(xterm->pid)); 29*5cde6096SJohannes Berg if (ret == -EAGAIN) 3063920f47SJeff Dike return IRQ_NONE; 311da177e4SLinus Torvalds 32*5cde6096SJohannes Berg if (ret < 0) 33*5cde6096SJohannes Berg fd = ret; 34*5cde6096SJohannes Berg else if (ret != sizeof(xterm->pid)) 35*5cde6096SJohannes Berg fd = -EMSGSIZE; 36*5cde6096SJohannes Berg 371da177e4SLinus Torvalds xterm->new_fd = fd; 381da177e4SLinus Torvalds complete(&xterm->ready); 3963920f47SJeff Dike 4063920f47SJeff Dike return IRQ_HANDLED; 411da177e4SLinus Torvalds } 421da177e4SLinus Torvalds 431da177e4SLinus Torvalds int xterm_fd(int socket, int *pid_out) 441da177e4SLinus Torvalds { 451da177e4SLinus Torvalds struct xterm_wait *data; 461da177e4SLinus Torvalds int err, ret; 471da177e4SLinus Torvalds 481da177e4SLinus Torvalds data = kmalloc(sizeof(*data), GFP_KERNEL); 491da177e4SLinus Torvalds if (data == NULL) { 501da177e4SLinus Torvalds printk(KERN_ERR "xterm_fd : failed to allocate xterm_wait\n"); 5163920f47SJeff Dike return -ENOMEM; 521da177e4SLinus Torvalds } 531da177e4SLinus Torvalds 541da177e4SLinus Torvalds /* This is a locked semaphore... */ 5563920f47SJeff Dike *data = ((struct xterm_wait) { .fd = socket, 561da177e4SLinus Torvalds .pid = -1, 571da177e4SLinus Torvalds .new_fd = -1 }); 581da177e4SLinus Torvalds init_completion(&data->ready); 591da177e4SLinus Torvalds 601da177e4SLinus Torvalds err = um_request_irq(XTERM_IRQ, socket, IRQ_READ, xterm_interrupt, 61aab94460STheodore Ts'o IRQF_SHARED, "xterm", data); 6236d46a59SJohannes Berg if (err < 0) { 631da177e4SLinus Torvalds printk(KERN_ERR "xterm_fd : failed to get IRQ for xterm, " 641da177e4SLinus Torvalds "err = %d\n", err); 651da177e4SLinus Torvalds ret = err; 661da177e4SLinus Torvalds goto out; 671da177e4SLinus Torvalds } 681da177e4SLinus Torvalds 691da177e4SLinus Torvalds /* ... so here we wait for an xterm interrupt. 701da177e4SLinus Torvalds * 711da177e4SLinus Torvalds * XXX Note, if the xterm doesn't work for some reason (eg. DISPLAY 721da177e4SLinus Torvalds * isn't set) this will hang... */ 731da177e4SLinus Torvalds wait_for_completion(&data->ready); 741da177e4SLinus Torvalds 75fa7a0449SRichard Weinberger um_free_irq(XTERM_IRQ, data); 761da177e4SLinus Torvalds 771da177e4SLinus Torvalds ret = data->new_fd; 781da177e4SLinus Torvalds *pid_out = data->pid; 791da177e4SLinus Torvalds out: 801da177e4SLinus Torvalds kfree(data); 811da177e4SLinus Torvalds 8263920f47SJeff Dike return ret; 831da177e4SLinus Torvalds } 84