1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com) 4 */ 5 6 #include <linux/interrupt.h> 7 #include <irq_kern.h> 8 #include <os.h> 9 #include <sigio.h> 10 11 /* Protected by sigio_lock() called from write_sigio_workaround */ 12 static int sigio_irq_fd = -1; 13 14 static irqreturn_t sigio_interrupt(int irq, void *data) 15 { 16 char c; 17 18 os_read_file(sigio_irq_fd, &c, sizeof(c)); 19 return IRQ_HANDLED; 20 } 21 22 int write_sigio_irq(int fd) 23 { 24 int err; 25 26 err = um_request_irq(SIGIO_WRITE_IRQ, fd, IRQ_READ, sigio_interrupt, 27 0, "write sigio", NULL); 28 if (err) { 29 printk(KERN_ERR "write_sigio_irq : um_request_irq failed, " 30 "err = %d\n", err); 31 return -1; 32 } 33 sigio_irq_fd = fd; 34 return 0; 35 } 36 37 /* These are called from os-Linux/sigio.c to protect its pollfds arrays. */ 38 static DEFINE_MUTEX(sigio_mutex); 39 40 void sigio_lock(void) 41 { 42 mutex_lock(&sigio_mutex); 43 } 44 45 void sigio_unlock(void) 46 { 47 mutex_unlock(&sigio_mutex); 48 } 49