tools: add a dedicated header file for barrier definitions

Instead of having to include xenctrl.h for getting definitions of cpu
barriers, add a dedicated header for that purpose.

Switch the xen-9pfsd daemon to use the new header instead of xenctrl.h.

This is in preparation of making Xenstore independent from libxenctrl.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>

tools/9pfsd/io.c

@@ -13,15 +13,18 @@
 
 #include <assert.h>
 #include <errno.h>
+#include <stdarg.h>
 #include <stdbool.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <syslog.h>
+#include <unistd.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <dirent.h>
 #include <fcntl.h>
-#include <xenctrl.h>           /* For cpu barriers. */
+#include <xen-barrier.h>
 #include <xen-tools/common-macros.h>
 
 #include "xen-9pfsd.h"

tools/include/xen-barrier.h

@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: LGPL-2.1-only */
+/******************************************************************************
+ * xen-barrier.h
+ *
+ * Definition of CPU barriers, part of libxenctrl.
+ *
+ * Copyright (c) 2003-2004, K A Fraser.
+ */
+
+#ifndef XEN_BARRIER_H
+#define XEN_BARRIER_H
+
+/*
+ *  DEFINITIONS FOR CPU BARRIERS
+ */
+
+#define xen_barrier() asm volatile ( "" : : : "memory")
+
+#if defined(__i386__)
+#define xen_mb()  asm volatile ( "lock addl $0, -4(%%esp)" ::: "memory" )
+#define xen_rmb() xen_barrier()
+#define xen_wmb() xen_barrier()
+#elif defined(__x86_64__)
+#define xen_mb()  asm volatile ( "lock addl $0, -32(%%rsp)" ::: "memory" )
+#define xen_rmb() xen_barrier()
+#define xen_wmb() xen_barrier()
+#elif defined(__arm__)
+#define xen_mb()   asm volatile ("dmb" : : : "memory")
+#define xen_rmb()  asm volatile ("dmb" : : : "memory")
+#define xen_wmb()  asm volatile ("dmb" : : : "memory")
+#elif defined(__aarch64__)
+#define xen_mb()   asm volatile ("dmb sy" : : : "memory")
+#define xen_rmb()  asm volatile ("dmb sy" : : : "memory")
+#define xen_wmb()  asm volatile ("dmb sy" : : : "memory")
+#else
+#error "Define barriers"
+#endif
+
+#endif /* XEN_BARRIER_H */

tools/include/xenctrl.h

@@ -48,6 +48,7 @@
 #include <xen/platform.h>
 
 #include "xentoollog.h"
+#include "xen-barrier.h"
 
 #if defined(__i386__) || defined(__x86_64__)
 #include <xen/foreign/x86_32.h>
@@ -61,33 +62,6 @@
 
 #define INVALID_MFN  (~0UL)
 
-/*
- *  DEFINITIONS FOR CPU BARRIERS
- */
-
-#define xen_barrier() asm volatile ( "" : : : "memory")
-
-#if defined(__i386__)
-#define xen_mb()  asm volatile ( "lock addl $0, -4(%%esp)" ::: "memory" )
-#define xen_rmb() xen_barrier()
-#define xen_wmb() xen_barrier()
-#elif defined(__x86_64__)
-#define xen_mb()  asm volatile ( "lock addl $0, -32(%%rsp)" ::: "memory" )
-#define xen_rmb() xen_barrier()
-#define xen_wmb() xen_barrier()
-#elif defined(__arm__)
-#define xen_mb()   asm volatile ("dmb" : : : "memory")
-#define xen_rmb()  asm volatile ("dmb" : : : "memory")
-#define xen_wmb()  asm volatile ("dmb" : : : "memory")
-#elif defined(__aarch64__)
-#define xen_mb()   asm volatile ("dmb sy" : : : "memory")
-#define xen_rmb()  asm volatile ("dmb sy" : : : "memory")
-#define xen_wmb()  asm volatile ("dmb sy" : : : "memory")
-#else
-#error "Define barriers"
-#endif
-
-
 #define XENCTRL_HAS_XC_INTERFACE 1
 /* In Xen 4.0 and earlier, xc_interface_open and xc_evtchn_open would
  * both return ints being the file descriptor.  In 4.1 and later, they

tools/libs/ctrl/Makefile

@@ -3,7 +3,7 @@ include $(XEN_ROOT)/tools/Rules.mk
 
 include Makefile.common
 
-LIBHEADER := xenctrl.h xenctrl_compat.h
+LIBHEADER := xenctrl.h xenctrl_compat.h xen-barrier.h
 PKG_CONFIG_FILE := xencontrol.pc
 PKG_CONFIG_NAME := Xencontrol