[4/4] x86: fold indirect_thunk_asm.h into asm-defns.h

Commit Message

Jan Beulich July 15, 2020, 10:49 a.m. UTC

There's little point in having two separate headers both getting
included by asm_defns.h. This in particular reduces the number of
instances of guarding asm(".include ...") suitably in such dual use
headers.

No change to generated code.

Signed-off-by: Jan Beulich <[e-mail]>

Comments

Roger Pau Monné July 27, 2020, 3:16 p.m. UTC | #1

On Wed, Jul 15, 2020 at 12:49:40PM +0200, Jan Beulich wrote:
> There's little point in having two separate headers both getting
> included by asm_defns.h. This in particular reduces the number of
> instances of guarding asm(".include ...") suitably in such dual use
> headers.
> 
> No change to generated code.
> 
> Signed-off-by: Jan Beulich <[e-mail]>

LGTM:

Reviewed-by: Roger Pau Monné <[e-mail]>

Some testing with clang might be required, as with the other patch.

Thanks, Roger.

Patch

--- a/xen/Makefile
+++ b/xen/Makefile
@@ -139,7 +139,7 @@  ifeq ($(TARGET_ARCH),x86)
 t1 = $(call as-insn,$(CC),".L0: .L1: .skip (.L1 - .L0)",,-no-integrated-as)
 
 # Check whether clang asm()-s support .include.
-t2 = $(call as-insn,$(CC) -I$(BASEDIR)/include,".include \"asm-x86/indirect_thunk_asm.h\"",,-no-integrated-as)
+t2 = $(call as-insn,$(CC) -I$(BASEDIR)/include,".include \"asm-x86/asm-defns.h\"",,-no-integrated-as)
 
 # Check whether clang keeps .macro-s between asm()-s:
 # https://bugs.llvm.org/show_bug.cgi?id=36110
--- a/xen/include/asm-x86/asm-defns.h
+++ b/xen/include/asm-x86/asm-defns.h
@@ -13,3 +13,40 @@ 
     .byte 0xf3, 0x0f, 0x01, 0xe8
 .endm
 #endif
+
+.macro INDIRECT_BRANCH insn:req arg:req
+/*
+ * Create an indirect branch.  insn is one of call/jmp, arg is a single
+ * register.
+ *
+ * With no compiler support, this degrades into a plain indirect call/jmp.
+ * With compiler support, dispatch to the correct __x86_indirect_thunk_*
+ */
+    .if CONFIG_INDIRECT_THUNK == 1
+
+        $done = 0
+        .irp reg, ax, cx, dx, bx, bp, si, di, 8, 9, 10, 11, 12, 13, 14, 15
+        .ifeqs "\arg", "%r\reg"
+            \insn __x86_indirect_thunk_r\reg
+            $done = 1
+           .exitm
+        .endif
+        .endr
+
+        .if $done != 1
+            .error "Bad register arg \arg"
+        .endif
+
+    .else
+        \insn *\arg
+    .endif
+.endm
+
+/* Convenience wrappers. */
+.macro INDIRECT_CALL arg:req
+    INDIRECT_BRANCH call \arg
+.endm
+
+.macro INDIRECT_JMP arg:req
+    INDIRECT_BRANCH jmp \arg
+.endm
--- a/xen/include/asm-x86/asm_defns.h
+++ b/xen/include/asm-x86/asm_defns.h
@@ -22,7 +22,6 @@ 
 asm ( "\t.equ CONFIG_INDIRECT_THUNK, "
       __stringify(IS_ENABLED(CONFIG_INDIRECT_THUNK)) );
 #endif
-#include <asm/indirect_thunk_asm.h>
 
 #ifndef __ASSEMBLY__
 void ret_from_intr(void);
--- a/xen/include/asm-x86/indirect_thunk_asm.h
+++ /dev/null
@@ -1,53 +0,0 @@ 
-/*
- * Trickery to allow this header to be included at the C level, to permit
- * proper dependency tracking in .*.o.d files, while still having it contain
- * assembler only macros.
- */
-#ifndef __ASSEMBLY__
-# if 0
-  .if 0
-# endif
-asm ( "\t.include \"asm/indirect_thunk_asm.h\"" );
-# if 0
-  .endif
-# endif
-#else
-
-.macro INDIRECT_BRANCH insn:req arg:req
-/*
- * Create an indirect branch.  insn is one of call/jmp, arg is a single
- * register.
- *
- * With no compiler support, this degrades into a plain indirect call/jmp.
- * With compiler support, dispatch to the correct __x86_indirect_thunk_*
- */
-    .if CONFIG_INDIRECT_THUNK == 1
-
-        $done = 0
-        .irp reg, ax, cx, dx, bx, bp, si, di, 8, 9, 10, 11, 12, 13, 14, 15
-        .ifeqs "\arg", "%r\reg"
-            \insn __x86_indirect_thunk_r\reg
-            $done = 1
-           .exitm
-        .endif
-        .endr
-
-        .if $done != 1
-            .error "Bad register arg \arg"
-        .endif
-
-    .else
-        \insn *\arg
-    .endif
-.endm
-
-/* Convenience wrappers. */
-.macro INDIRECT_CALL arg:req
-    INDIRECT_BRANCH call \arg
-.endm
-
-.macro INDIRECT_JMP arg:req
-    INDIRECT_BRANCH jmp \arg
-.endm
-
-#endif