1 /*
2 * Copyright (c) 2010, XenSource Inc.
3 * All rights reserved.
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public License
7 * as published by the Free Software Foundation; either version 2 of
8 * the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; If not, see <http://www.gnu.org/licenses/>.
17 */
18
19 /*
20 * kernel 2.6.21 added eventfd(2) support, kernel 2.6.22 eventfds for
21 * aio. libaio 0.3.107 updated the header file, but few systems have
22 * it. define a custom iocb_common struct instead, and work around a
23 * potentially missing sys/eventfd.h. this header should vanish over
24 * time.
25 */
26
27 #ifndef __LIBAIO_COMPAT
28 #define __LIBAIO_COMPAT
29
30 #include "../../config.h"
31 #include <libaio.h>
32 #include <unistd.h>
33 #include <sys/syscall.h>
34
35 struct __compat_io_iocb_common {
36 char __pad_buf[8];
37 char __pad_nbytes[8];
38 long long offset;
39 long long __pad3;
40 unsigned flags;
41 unsigned resfd;
42 };
43
__io_set_eventfd(struct iocb * iocb,int eventfd)44 static inline void __io_set_eventfd(struct iocb *iocb, int eventfd)
45 {
46 struct __compat_io_iocb_common *c;
47 c = (struct __compat_io_iocb_common*)&iocb->u.c;
48 c->flags |= (1 << 0);
49 c->resfd = eventfd;
50 }
51
52 #ifdef HAVE_SYS_EVENTFD_H
53
54 #include <sys/eventfd.h>
55
tapdisk_sys_eventfd(int initval)56 static inline int tapdisk_sys_eventfd(int initval)
57 {
58 return eventfd(initval, 0);
59 }
60
61 #else /* Fallback */
62 #ifndef SYS_eventfd
63 #ifndef __NR_eventfd
64 # if defined(__alpha__)
65 # define __NR_eventfd 478
66 # elif defined(__arm__)
67 # define __NR_eventfd (__NR_SYSCALL_BASE+351)
68 # elif defined(__ia64__)
69 # define __NR_eventfd 1309
70 # elif defined(__i386__)
71 # define __NR_eventfd 323
72 # elif defined(__m68k__)
73 # define __NR_eventfd 319
74 # elif 0 && defined(__mips__)
75 # error __NR_eventfd?
76 # define __NR_eventfd (__NR_Linux + 319)
77 # define __NR_eventfd (__NR_Linux + 278)
78 # define __NR_eventfd (__NR_Linux + 282)
79 # elif defined(__hppa__)
80 # define __NR_eventfd (__NR_Linux + 304)
81 # elif defined(__PPC__) || defined(__powerpc64__)
82 # define __NR_eventfd 307
83 # elif defined(__s390__) || defined(__s390x__)
84 # define __NR_eventfd 318
85 # elif defined(__sparc__)
86 # define __NR_eventfd 313
87 # elif defined(__x86_64__)
88 # define __NR_eventfd 284
89 # endif
90 #else
91 # error __NR_eventfd?
92 #endif
93 #define SYS_eventfd __NR_eventfd
94 #endif
95
tapdisk_sys_eventfd(int initval)96 static inline int tapdisk_sys_eventfd(int initval)
97 {
98 return syscall(SYS_eventfd, initval, 0);
99 }
100 #endif
101
102 #endif /* __LIBAIO_COMPAT */
103