tables.h: make DECLARE_LINKTABLE() .data by default

Upon review with hpa its better to have the shorter version for
what we expect linker tables to be used for mostly, and that is data.
DECLARE_LINKTABLE_TEXT() is then required for .text.

Expand documentation on that we have then only two declarations
also:

  o DECLARE_LINKTABLE()        for data
  o DECLARE_LINKTABLE_RO()     for read-only data

The definitions are used to associate these with actual sections
on the code that implements support for the table.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>

4 files changed, 45 insertions, 34 deletions

diff --git a/README b/README
index 93e2d7e..f831932 100644
--- a/README
+++ b/README
@@ -69,17 +69,27 @@ SECTION_TYPE_RANGES |.ranges | DECLARE_SECTION_RANGE() | DEFINE_SECTION_RANGE()
 SECTION_TYPE_TABLES |.ranges |  DECLARE_LINKTABLE*()   | DEFINE_LINKTABLE*()
 -------------------------------------------------------------------------------
 
+There are only two declarations for linker tables, which would be used in
+header files:
+
+  o DECLARE_LINKTABLE()		for data
+  o DECLARE_LINKTABLE_RO()	for read-only data
+
 The tables have a series of definitions (DEFINE_LINKTABLE_*()) given to help
-with setup for the different supported Linux sections used. The definitions for
-tables then are:
+with setup for the different supported Linux sections used. The definitions
+would be used in the code defining the use of tables -- the actual
+implementation.
+
+The definitions currently supported for tables are:
 
 -------------------------------------------------------------------------------
 Linux section    |    const-or-not  |  Definition
 -------------------------------------------------------------------------------
-.text            |    const         |  DEFINE_LINKTABLE()
-.data            |    non-const     |  DEFINE_LINKTABLE_DATA()
-.init            |    const         |  LINKTABLE_INIT()
-.init.data       |    non-const     |  LINKTABLE_INIT_DATA()
+.data            |    non-const     |  DEFINE_LINKTABLE()
+.text            |    const         |  DEFINE_LINKTABLE_TEXT()
+.init            |    const         |  DEFINE_LINKTABLE_INIT()
+.init.data       |    non-const     |  DEFINE_LINKTABLE_INIT_DATA()
+.rodata          |    const         |  DEFINE_LINKTABLE_RO()
 -------------------------------------------------------------------------------
 
 x86 bzimage parser
diff --git a/arch/x86/include/asm/x86_init_fn.h b/arch/x86/include/asm/x86_init_fn.h
index c035a89..2490dc7 100644
--- a/arch/x86/include/asm/x86_init_fn.h
+++ b/arch/x86/include/asm/x86_init_fn.h
@@ -111,7 +111,7 @@ struct x86_init_fn {
 	void (*early_init)(void);
 };
 
-DECLARE_LINKTABLE_DATA(struct x86_init_fn, x86_init_fns);
+DECLARE_LINKTABLE(struct x86_init_fn, x86_init_fns);
 
 /* Init order levels, we can start at 0000 but reserve 0000-0999 for now */
 
diff --git a/include/linux/init.h b/include/linux/init.h
index 14c6422..1951514 100644
--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -11,8 +11,8 @@
 typedef int (*initcall_t)(void);
 typedef void (*exitcall_t)(void);
 
-DECLARE_LINKTABLE_DATA(initcall_t, init_calls);
-DECLARE_LINKTABLE_DATA(exitcall_t, exit_calls);
+DECLARE_LINKTABLE(initcall_t, init_calls);
+DECLARE_LINKTABLE(exitcall_t, exit_calls);
 
 #define __define_initcall(fn, id)					\
 	static LINKTABLE_INIT_DATA(init_calls, id)			\
diff --git a/include/linux/tables.h b/include/linux/tables.h
index 9b161ff..fce59fc 100644
--- a/include/linux/tables.h
+++ b/include/linux/tables.h
@@ -33,14 +33,14 @@
 	 (addr >= (unsigned long) LINUX_SECTION_START(tbl) &&		\
           addr < (unsigned long) LINUX_SECTION_END(tbl))
 
-#define LINKTABLE_DATA_WEAK(name, level)				\
+#define LINKTABLE_WEAK(name, level)					\
 	      __typeof__(name[0])					\
 	      __attribute__((used,					\
 			     weak,					\
 			     __aligned__(LINUX_SECTION_ALIGN_STRUCT),	\
 			     section(SECTION_TBL(SECTION_DATA, name, level))))
 
-#define LINKTABLE_WEAK(name, level)					\
+#define LINKTABLE_TEXT_WEAK(name, level)					\
 	const __typeof__(name[0])					\
 	      __attribute__((used,					\
 			     weak,					\
@@ -70,16 +70,17 @@
 			     section(SECTION_TBL(SECTION_INIT_DATA, name, level))))
 
 #define LINKTABLE(name, level)						\
-	const __typeof__(name[0])					\
+	      __typeof__(name[0])					\
 	      __attribute__((used,					\
 			     __aligned__(LINUX_SECTION_ALIGN_FUNC),	\
-			     section(SECTION_TBL(SECTION_TEXT, name, level))))
+			     section(SECTION_TBL(SECTION_DATA, name, level))))
 
-#define LINKTABLE_DATA(name, level)					\
-	      __typeof__(name[0])					\
+#define LINKTABLE_TEXT(name, level)					\
+	const __typeof__(name[0])					\
 	      __attribute__((used,					\
 			     __aligned__(LINUX_SECTION_ALIGN_FUNC),	\
-			     section(SECTION_TBL(SECTION_DATA, name, level))))
+			     section(SECTION_TBL(SECTION_TEXT, name, level))))
+
 #define LINKTABLE_RO(name, level)					\
 	const __typeof__(name[0])					\
 	      __attribute__((used,					\
@@ -98,11 +99,11 @@
 			     section(SECTION_TBL(SECTION_INIT_DATA, name, level))))
 
 #define DECLARE_LINKTABLE(type, name)					\
-	DECLARE_LINUX_SECTION_RO(type, name)
-
-#define DECLARE_LINKTABLE_DATA(type, name)				\
 	DECLARE_LINUX_SECTION(type, name)
 
+#define DECLARE_LINKTABLE_RO(type, name)				\
+	DECLARE_LINUX_SECTION_RO(type, name)
+
 #define DEFINE_LINKTABLE(type, name)					\
 	DECLARE_LINKTABLE(type, name);					\
 	LINKTABLE_WEAK(name, ) VMLINUX_SYMBOL(name)[0] = {};		\
@@ -110,36 +111,36 @@
 	LINKTABLE(name, ~) VMLINUX_SYMBOL(name##__end)[0] = {};		\
 	LTO_REFERENCE_INITCALL(name##__end);
 
-#define DEFINE_LINKTABLE_DATA(type, name)				\
-	DECLARE_LINKTABLE_DATA(type, name);				\
-	LINKTABLE_DATA_WEAK(name, ) VMLINUX_SYMBOL(name)[0] = {};	\
+#define DEFINE_LINKTABLE_TEXT(type, name)				\
+	DECLARE_LINKTABLE_RO(type, name);				\
+	LINKTABLE_WEAK_TEXT(name, ) VMLINUX_SYMBOL(name)[0] = {};	\
 	LTO_REFERENCE_INITCALL(name);					\
-	LINKTABLE_DATA(name, ~) VMLINUX_SYMBOL(name##__end)[0] = {};\
+	LINKTABLE_TEXT(name, ~) VMLINUX_SYMBOL(name##__end)[0] = {};	\
 	LTO_REFERENCE_INITCALL(name##__end);
 
 #define DEFINE_LINKTABLE_RO(type, name)					\
-	DECLARE_LINKTABLE(type, name);					\
+	DECLARE_LINKTABLE_RO(type, name);				\
 	LINKTABLE_RO_WEAK(name, ) VMLINUX_SYMBOL(name)[0] = {};		\
 	LTO_REFERENCE_INITCALL(name);					\
 	LINKTABLE_RO(name, ~) VMLINUX_SYMBOL(name##__end)[0] = {};	\
 	LTO_REFERENCE_INITCALL(name##__end);
 
-#define DEFINE_LINKTABLE_INIT(type, name)					\
-	DECLARE_LINKTABLE(type, name);						\
-	LINKTABLE_INIT_WEAK(name, ) VMLINUX_SYMBOL(name)[0] = {};		\
-	LTO_REFERENCE_INITCALL(name);						\
+#define DEFINE_LINKTABLE_INIT(type, name)				\
+	DECLARE_LINKTABLE(type, name);					\
+	LINKTABLE_INIT_WEAK(name, ) VMLINUX_SYMBOL(name)[0] = {};	\
+	LTO_REFERENCE_INITCALL(name);					\
 	LINKTABLE_INIT(name, ~) VMLINUX_SYMBOL(name##__end)[0] = {};	\
 	LTO_REFERENCE_INITCALL(name##__end);
 
-#define DEFINE_LINKTABLE_INIT_DATA(type, name)					\
-	DECLARE_LINKTABLE_DATA(type, name);					\
-	LINKTABLE_INIT_DATA_WEAK(name, ) VMLINUX_SYMBOL(name)[0] = {};		\
-	LTO_REFERENCE_INITCALL(name);						\
-	LINKTABLE_INIT_DATA(name, ~) VMLINUX_SYMBOL(name##__end)[0] = {};	\
+#define DEFINE_LINKTABLE_INIT_DATA(type, name)				\
+	DECLARE_LINKTABLE(type, name);					\
+	LINKTABLE_INIT_DATA_WEAK(name, ) VMLINUX_SYMBOL(name)[0] = {};	\
+	LTO_REFERENCE_INITCALL(name);					\
+	LINKTABLE_INIT_DATA(name, ~) VMLINUX_SYMBOL(name##__end)[0] = {};\
 	LTO_REFERENCE_INITCALL(name##__end);
 
 #define LINKTABLE_FOR_EACH(pointer, tbl)				\
-	for (pointer = LINUX_SECTION_START(tbl);				\
+	for (pointer = LINUX_SECTION_START(tbl);			\
 	     pointer < LINUX_SECTION_END(tbl);				\
 	     pointer++)