1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 4 */ 5 6 #include <linux/slab.h> 7 #include <linux/completion.h> 8 #include <linux/irqreturn.h> 9 #include <asm/irq.h> 10 #include <irq_kern.h> 11 #include <os.h> 12 #include "xterm.h" 13 14 struct xterm_wait { 15 struct completion ready; 16 int fd; 17 int pid; 18 int new_fd; 19 }; 20 21 static irqreturn_t xterm_interrupt(int irq, void *data) 22 { 23 struct xterm_wait *xterm = data; 24 int fd; 25 26 fd = os_rcv_fd(xterm->fd, &xterm->pid); 27 if (fd == -EAGAIN) 28 return IRQ_NONE; 29 30 xterm->new_fd = fd; 31 complete(&xterm->ready); 32 33 return IRQ_HANDLED; 34 } 35 36 int xterm_fd(int socket, int *pid_out) 37 { 38 struct xterm_wait *data; 39 int err, ret; 40 41 data = kmalloc(sizeof(*data), GFP_KERNEL); 42 if (data == NULL) { 43 printk(KERN_ERR "xterm_fd : failed to allocate xterm_wait\n"); 44 return -ENOMEM; 45 } 46 47 /* This is a locked semaphore... */ 48 *data = ((struct xterm_wait) { .fd = socket, 49 .pid = -1, 50 .new_fd = -1 }); 51 init_completion(&data->ready); 52 53 err = um_request_irq(XTERM_IRQ, socket, IRQ_READ, xterm_interrupt, 54 IRQF_SHARED, "xterm", data); 55 if (err < 0) { 56 printk(KERN_ERR "xterm_fd : failed to get IRQ for xterm, " 57 "err = %d\n", err); 58 ret = err; 59 goto out; 60 } 61 62 /* ... so here we wait for an xterm interrupt. 63 * 64 * XXX Note, if the xterm doesn't work for some reason (eg. DISPLAY 65 * isn't set) this will hang... */ 66 wait_for_completion(&data->ready); 67 68 um_free_irq(XTERM_IRQ, data); 69 70 ret = data->new_fd; 71 *pid_out = data->pid; 72 out: 73 kfree(data); 74 75 return ret; 76 } 77