1 /* 2 * Copyright (C) 2002 - 2003 Jeff Dike (jdike@addtoit.com) 3 * Licensed under the GPL 4 */ 5 6 #include "linux/kernel.h" 7 #include "linux/list.h" 8 #include "linux/slab.h" 9 #include "linux/signal.h" 10 #include "linux/interrupt.h" 11 #include "init.h" 12 #include "sigio.h" 13 #include "irq_user.h" 14 #include "irq_kern.h" 15 #include "os.h" 16 17 /* Protected by sigio_lock() called from write_sigio_workaround */ 18 static int sigio_irq_fd = -1; 19 20 static irqreturn_t sigio_interrupt(int irq, void *data, struct pt_regs *unused) 21 { 22 char c; 23 24 os_read_file(sigio_irq_fd, &c, sizeof(c)); 25 reactivate_fd(sigio_irq_fd, SIGIO_WRITE_IRQ); 26 return(IRQ_HANDLED); 27 } 28 29 int write_sigio_irq(int fd) 30 { 31 int err; 32 33 err = um_request_irq(SIGIO_WRITE_IRQ, fd, IRQ_READ, sigio_interrupt, 34 IRQF_DISABLED|IRQF_SAMPLE_RANDOM, "write sigio", 35 NULL); 36 if(err){ 37 printk("write_sigio_irq : um_request_irq failed, err = %d\n", 38 err); 39 return(-1); 40 } 41 sigio_irq_fd = fd; 42 return(0); 43 } 44 45 static DEFINE_SPINLOCK(sigio_spinlock); 46 47 void sigio_lock(void) 48 { 49 spin_lock(&sigio_spinlock); 50 } 51 52 void sigio_unlock(void) 53 { 54 spin_unlock(&sigio_spinlock); 55 } 56