common: assembly entry point type/size annotations

Recent gas versions generate minimalistic Dwarf debug info for items
annotated as functions and having their sizes specified [1]. Furthermore
generating live patches wants items properly annotated. "Borrow" Arm's
END() and (remotely) derive other annotation infrastructure from
Linux'es, for all architectures to use.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
[1] https://sourceware.org/git?p=binutils-gdb.git;a=commitdiff;h=591cc9fbbfd6d51131c0f1d4a92e7893edcc7a28

diff --git a/xen/include/xen/linkage.h b/xen/include/xen/linkage.h
new file mode 100644 (file)
index 0000000..52fe4df
--- /dev/null
+++ b/xen/include/xen/linkage.h
@@ -0,0 +1,54 @@
+#ifndef __LINKAGE_H__
+#define __LINKAGE_H__
+
+#ifdef __ASSEMBLY__
+
+#include <xen/macros.h>
+
+/* CODE_ALIGN needs to be specified by every architecture. */
+#ifndef CODE_FILL
+# define CODE_FILL ~0
+#endif
+
+#ifndef DATA_ALIGN
+# define DATA_ALIGN 0
+#endif
+#ifndef DATA_FILL
+# define DATA_FILL ~0
+#endif
+
+#define SYM_ALIGN(align...) .balign align
+
+#define SYM_L_GLOBAL(name) .globl name
+#define SYM_L_WEAK(name)   .weak name
+#define SYM_L_LOCAL(name)  /* nothing */
+
+#define SYM_T_FUNC         STT_FUNC
+#define SYM_T_DATA         STT_OBJECT
+#define SYM_T_NONE         STT_NOTYPE
+
+#define SYM(name, typ, linkage, align...)         \
+        .type name, SYM_T_ ## typ;                \
+        SYM_L_ ## linkage(name);                  \
+        SYM_ALIGN(align);                         \
+        name:
+
+#define END(name) .size name, . - name
+
+#define FUNC(name, align...) \
+        SYM(name, FUNC, GLOBAL, LASTARG(CODE_ALIGN, ## align), CODE_FILL)
+#define LABEL(name, align...) \
+        SYM(name, NONE, GLOBAL, LASTARG(CODE_ALIGN, ## align), CODE_FILL)
+#define DATA(name, align...) \
+        SYM(name, DATA, GLOBAL, LASTARG(DATA_ALIGN, ## align), DATA_FILL)
+
+#define FUNC_LOCAL(name, align...) \
+        SYM(name, FUNC, LOCAL, LASTARG(CODE_ALIGN, ## align), CODE_FILL)
+#define LABEL_LOCAL(name, align...) \
+        SYM(name, NONE, LOCAL, LASTARG(CODE_ALIGN, ## align), CODE_FILL)
+#define DATA_LOCAL(name, align...) \
+        SYM(name, DATA, LOCAL, LASTARG(DATA_ALIGN, ## align), DATA_FILL)
+
+#endif /*  __ASSEMBLY__ */
+
+#endif /* __LINKAGE_H__ */

diff --git a/xen/include/xen/macros.h b/xen/include/xen/macros.h
index 18842cd8a511d09badf19024edab25acf6256e79..e64373f0187d7bc4881904fc98d3e17459d3affb 100644 (file)
--- a/xen/include/xen/macros.h
+++ b/xen/include/xen/macros.h
@@ -21,6 +21,15 @@
 #define count_args(args...) \
     count_args_(., ## args, 8, 7, 6, 5, 4, 3, 2, 1, 0)
 
+#define ARG1_(x, y...) (x)
+#define ARG2_(x, y...) ARG1_(y)
+#define ARG3_(x, y...) ARG2_(y)
+#define ARG4_(x, y...) ARG3_(y)
+
+#define ARG__(nr) ARG ## nr ## _
+#define ARG_(nr)  ARG__(nr)
+#define LASTARG(x, y...) ARG_(count_args(x, ## y))(x, ## y)
+
 /* Indirect macros required for expanded argument pasting. */
 #define PASTE_(a, b) a ## b
 #define PASTE(a, b) PASTE_(a, b)