Archipelago » blktap-utils

/*

 * Copyright (c) 2010, XenSource Inc.

 * All rights reserved.

 *

 * This  library is  free  software; you  can  redistribute it  and/or

 * modify it under the terms  of the GNU Lesser General Public License

 * as published by  the Free Software Foundation; either  version 2 of

 * the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful, but

 * WITHOUT  ANY  WARRANTY;  without   even  the  implied  warranty  of

 * MERCHANTABILITY or  FITNESS FOR A PARTICULAR PURPOSE.   See the GNU

 * Lesser General Public License for more details.

 *

 * You should  have received a copy  of the GNU  Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307

 * USA

 */

/*

 * kernel 2.6.21 added eventfd(2) support, kernel 2.6.22 eventfds for

 * aio. libaio 0.3.107 updated the header file, but few systems have

 * it. define a custom iocb_common struct instead, and work around a

 * potentially missing sys/eventfd.h. this header should vanish over

 * time.

 */

#ifndef __LIBAIO_COMPAT

#define __LIBAIO_COMPAT

#include <libaio.h>

#include <unistd.h>

#include <sys/syscall.h>

struct __compat_io_iocb_common {

        char             __pad_buf[8];

        char             __pad_nbytes[8];

        long long        offset;

        long long        __pad3;

        unsigned        flags;

        unsigned        resfd;

};

static inline void __io_set_eventfd(struct iocb *iocb, int eventfd)

{

        struct __compat_io_iocb_common *c;

        c = (struct __compat_io_iocb_common*)&iocb->u.c;

        c->flags |= (1 << 0);

        c->resfd = eventfd;

}

#ifndef SYS_eventfd

#ifndef __NR_eventfd

# if defined(__alpha__)

#  define __NR_eventfd                478

# elif defined(__arm__)

#  define __NR_eventfd                (__NR_SYSCALL_BASE+351)

# elif defined(__ia64__)

#  define __NR_eventfd                1309

# elif defined(__i386__)

#  define __NR_eventfd                323

# elif defined(__m68k__)

#  define __NR_eventfd                319

# elif 0 && defined(__mips__)

#  error __NR_eventfd?

#  define __NR_eventfd                (__NR_Linux + 319)

#  define __NR_eventfd                (__NR_Linux + 278)

#  define __NR_eventfd                (__NR_Linux + 282)

# elif defined(__hppa__)

#  define __NR_eventfd                (__NR_Linux + 304)

# elif defined(__PPC__) || defined(__powerpc64__)

#  define __NR_eventfd                307

# elif defined(__s390__) || defined(__s390x__)

#  define __NR_eventfd                318

# elif defined(__sparc__)

#  define __NR_eventfd                313

# elif defined(__x86_64__)

#  define __NR_eventfd                284

# endif

#else

# error __NR_eventfd?

#endif

#define SYS_eventfd __NR_eventfd

#endif

static inline int tapdisk_sys_eventfd(int initval)

{

        return syscall(SYS_eventfd, initval, 0);

}

#endif /* __LIBAIO_COMPAT */