1 /******************************************************************************
4 * Communication via Xen event channels.
5 * Also definitions for the device that demuxes notifications to userspace.
7 * Copyright (c) 2004-2005, K A Fraser
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License version 2
11 * as published by the Free Software Foundation; or, when distributed
12 * separately from the Linux kernel or incorporated into other
13 * software packages, subject to the following license:
15 * Permission is hereby granted, free of charge, to any person obtaining a copy
16 * of this source file (the "Software"), to deal in the Software without
17 * restriction, including without limitation the rights to use, copy, modify,
18 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
19 * and to permit persons to whom the Software is furnished to do so, subject to
20 * the following conditions:
22 * The above copyright notice and this permission notice shall be included in
23 * all copies or substantial portions of the Software.
25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
26 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
27 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
28 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
29 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
30 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
34 #ifndef __ASM_EVTCHN_H__
35 #define __ASM_EVTCHN_H__
37 #include <linux/interrupt.h>
38 #include <asm/hypervisor.h>
39 #include <asm/ptrace.h>
40 #include <asm/synch_bitops.h>
41 #include <xen/interface/event_channel.h>
42 #include <linux/smp.h>
45 * LOW-LEVEL DEFINITIONS
49 * Dynamically bind an event source to an IRQ-like callback handler.
50 * On some platforms this may not be implemented via the Linux IRQ subsystem.
51 * The IRQ argument passed to the callback handler is the same as returned
52 * from the bind call. It may not correspond to a Linux IRQ number.
53 * Returns IRQ or negative errno.
54 * UNBIND: Takes IRQ to unbind from; automatically closes the event channel.
56 extern int bind_evtchn_to_irqhandler(
58 irqreturn_t (*handler)(int, void *, struct pt_regs *),
59 unsigned long irqflags,
62 extern int bind_virq_to_irqhandler(
65 irqreturn_t (*handler)(int, void *, struct pt_regs *),
66 unsigned long irqflags,
69 extern int bind_ipi_to_irqhandler(
72 irqreturn_t (*handler)(int, void *, struct pt_regs *),
73 unsigned long irqflags,
78 * Common unbind function for all event sources. Takes IRQ to unbind from.
79 * Automatically closes the underlying event channel (even for bindings
80 * made with bind_evtchn_to_irqhandler()).
82 extern void unbind_from_irqhandler(unsigned int irq, void *dev_id);
84 extern void irq_resume(void);
86 /* Entry point for notifications into Linux subsystems. */
87 asmlinkage void evtchn_do_upcall(struct pt_regs *regs);
89 /* Entry point for notifications into the userland character device. */
90 extern void evtchn_device_upcall(int port);
92 extern void mask_evtchn(int port);
93 extern void unmask_evtchn(int port);
95 static inline void clear_evtchn(int port)
97 shared_info_t *s = HYPERVISOR_shared_info;
98 synch_clear_bit(port, &s->evtchn_pending[0]);
101 static inline void notify_remote_via_evtchn(int port)
103 struct evtchn_send send = { .port = port };
104 (void)HYPERVISOR_event_channel_op(EVTCHNOP_send, &send);
108 * Unlike notify_remote_via_evtchn(), this is safe to use across
109 * save/restore. Notifications on a broken connection are silently dropped.
111 extern void notify_remote_via_irq(int irq);
113 #endif /* __ASM_EVTCHN_H__ */