[linux] Add nap

Signed-off-by: Piotr Jaroszyński <p.jaroszynski@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/config/defaults/linux.h

@@ -11,6 +11,7 @@
 #define TIMER_LINUX
 #define UACCESS_LINUX
 #define UMALLOC_LINUX
+#define NAP_LINUX
 
 #define IMAGE_SCRIPT
 

src/include/ipxe/linux/linux_nap.h

@@ -0,0 +1,18 @@
+#ifndef _IPXE_LINUX_NAP_H
+#define _IPXE_LINUX_NAP_H
+
+/** @file
+ *
+ * Linux CPU sleeping
+ *
+ */
+
+FILE_LICENCE(GPL2_OR_LATER);
+
+#ifdef NAP_LINUX
+#define NAP_PREFIX_linux
+#else
+#define NAP_PREFIX_linux __linux_
+#endif
+
+#endif /* _IPXE_LINUX_NAP_H */

src/include/ipxe/nap.h

@@ -43,6 +43,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
 
 /* Include all architecture-independent I/O API headers */
 #include <ipxe/null_nap.h>
+#include <ipxe/linux/linux_nap.h>
 
 /* Include all architecture-dependent I/O API headers */
 #include <bits/nap.h>

src/interface/linux/linux_nap.c

@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2010 Piotr Jaroszyński <p.jaroszynski@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+FILE_LICENCE(GPL2_OR_LATER);
+
+#include <ipxe/nap.h>
+
+#include <linux_api.h>
+
+/** @file
+ *
+ * iPXE CPU sleeping API for linux
+ *
+ */
+
+/**
+ * Sleep until next CPU interrupt
+ *
+ */
+static void linux_cpu_nap(void)
+{
+	linux_usleep(0);
+}
+
+PROVIDE_NAP(linux, cpu_nap, linux_cpu_nap);