Add support for AIX

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/os/os-aix.h b/os/os-aix.h
new file mode 100644
index 0000000..1cc35e8
--- /dev/null
+++ b/os/os-aix.h
@@ -0,0 +1,46 @@
+#ifndef FIO_OS_AIX_H
+#define FIO_OS_AIX_H
+
+#include <errno.h>
+#include <unistd.h>
+#include <sys/devinfo.h>
+#include <sys/ioctl.h>
+
+#define FIO_HAVE_POSIXAIO
+#define FIO_HAVE_FALLOCATE
+#define FIO_HAVE_ODIRECT
+#define FIO_USE_GENERIC_RAND
+
+#define FIO_HAVE_PSHARED_MUTEX
+
+#define OS_MAP_ANON		MAP_ANON
+
+static inline int blockdev_invalidate_cache(int fd)
+{
+	return EINVAL;
+}
+
+static inline int blockdev_size(int fd, unsigned long long *bytes)
+{
+	struct devinfo info;
+
+	if (!ioctl(fd, IOCINFO, &info)) {
+        	*bytes = (unsigned long long)info.un.scdk.numblks *
+				info.un.scdk.blksize;
+		return 0;
+	}
+
+	return errno;
+}
+
+static inline unsigned long long os_phys_mem(void)
+{
+	long mem = sysconf(_SC_AIX_REALMEM);
+
+	if (mem == -1)
+		return 0;
+
+	return (unsigned long long) mem * 1024;
+}
+
+#endif
diff --git a/os/os.h b/os/os.h
index 218766a..e2bb0ba 100644
--- a/os/os.h
+++ b/os/os.h
@@ -14,6 +14,8 @@
 #include "os-solaris.h"
 #elif defined(__APPLE__)
 #include "os-mac.h"
+#elif defined(_AIX)
+#include "os-aix.h"
 #else
 #error "unsupported os"
 #endif