1/* 2 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com) 3 * Licensed under the GPL 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 */ 12static int sigio_irq_fd = -1; 13 14static irqreturn_t sigio_interrupt(int irq, void *data) 15{ 16 char c; 17 18 os_read_file(sigio_irq_fd, &c, sizeof(c)); 19 reactivate_fd(sigio_irq_fd, SIGIO_WRITE_IRQ); 20 return IRQ_HANDLED; 21} 22 23int write_sigio_irq(int fd) 24{ 25 int err; 26 27 err = um_request_irq(SIGIO_WRITE_IRQ, fd, IRQ_READ, sigio_interrupt, 28 IRQF_DISABLED|IRQF_SAMPLE_RANDOM, "write sigio", 29 NULL); 30 if (err) { 31 printk(KERN_ERR "write_sigio_irq : um_request_irq failed, " 32 "err = %d\n", err); 33 return -1; 34 } 35 sigio_irq_fd = fd; 36 return 0; 37} 38 39/* These are called from os-Linux/sigio.c to protect its pollfds arrays. */ 40static DEFINE_SPINLOCK(sigio_spinlock); 41 42void sigio_lock(void) 43{ 44 spin_lock(&sigio_spinlock); 45} 46 47void sigio_unlock(void) 48{ 49 spin_unlock(&sigio_spinlock); 50} 51