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 */ 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 reactivate_fd(sigio_irq_fd, SIGIO_WRITE_IRQ); 20 return IRQ_HANDLED; 21 } 22 23 int write_sigio_irq(int fd) 24 { 25 int err; 26 27 err = um_request_irq(SIGIO_WRITE_IRQ, fd, IRQ_READ, sigio_interrupt, 28 0, "write sigio", NULL); 29 if (err) { 30 printk(KERN_ERR "write_sigio_irq : um_request_irq failed, " 31 "err = %d\n", err); 32 return -1; 33 } 34 sigio_irq_fd = fd; 35 return 0; 36 } 37 38 /* These are called from os-Linux/sigio.c to protect its pollfds arrays. */ 39 static DEFINE_SPINLOCK(sigio_spinlock); 40 41 void sigio_lock(void) 42 { 43 spin_lock(&sigio_spinlock); 44 } 45 46 void sigio_unlock(void) 47 { 48 spin_unlock(&sigio_spinlock); 49 } 50