[PATCH] i386: always enable regparm

-mregparm=3 has been enabled by default for some time on i386, and AFAIK
there aren't any problems with it left.

This patch removes the REGPARM config option and sets -mregparm=3
unconditionally.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andi Kleen <ak@suse.de>

4 files changed, 2 insertions, 27 deletions

diff --git a/Documentation/stable_api_nonsense.txt b/Documentation/stable_api_nonsense.txt
index f39c9d714db3..a2afca3b2bab 100644
--- a/Documentation/stable_api_nonsense.txt
+++ b/Documentation/stable_api_nonsense.txt
@@ -62,9 +62,6 @@ consider the following facts about the Linux kernel:
       - different structures can contain different fields
       - Some functions may not be implemented at all, (i.e. some locks
         compile away to nothing for non-SMP builds.)
-      - Parameter passing of variables from function to function can be
-        done in different ways (the CONFIG_REGPARM option controls
-        this.)
       - Memory within the kernel can be aligned in different ways,
         depending on the build options.
   - Linux runs on a wide range of different processor architectures.
diff --git a/arch/i386/Kconfig b/arch/i386/Kconfig
index bb1fa061c6cf..b6b2df40ca78 100644
--- a/arch/i386/Kconfig
+++ b/arch/i386/Kconfig
@@ -721,20 +721,6 @@ config BOOT_IOREMAP
         depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
         default y
 
-config REGPARM
-        bool "Use register arguments"
-        default y
-        help
-        Compile the kernel with -mregparm=3. This instructs gcc to use
-        a more efficient function call ABI which passes the first three
-        arguments of a function call via registers, which results in denser
-        and faster code.
-
-        If this option is disabled, then the default ABI of passing
-        arguments via the stack is used.
-
-        If unsure, say Y.
-
 config SECCOMP
         bool "Enable seccomp to safely compute untrusted bytecode"
         depends on PROC_FS
diff --git a/arch/i386/Makefile b/arch/i386/Makefile
index d1aca52bf690..f7ac1aea1d8a 100644
--- a/arch/i386/Makefile
+++ b/arch/i386/Makefile
@@ -31,7 +31,7 @@ LDFLAGS_vmlinux := --emit-relocs
 endif
 CHECKFLAGS      += -D__i386__
 
-CFLAGS += -pipe -msoft-float
+CFLAGS += -pipe -msoft-float -mregparm=3
 
 # prevent gcc from keeping the stack 16 byte aligned
 CFLAGS += $(call cc-option,-mpreferred-stack-boundary=2)
@@ -39,8 +39,6 @@ CFLAGS += $(call cc-option,-mpreferred-stack-boundary=2)
 # CPU-specific tuning. Anything which can be shared with UML should go here.
 include $(srctree)/arch/i386/Makefile.cpu
 
-cflags-$(CONFIG_REGPARM) += -mregparm=3
-
 # temporary until string.h is fixed
 cflags-y += -ffreestanding
 
diff --git a/include/asm-i386/module.h b/include/asm-i386/module.h
index fe5ae42e0273..02f8f541cbe0 100644
--- a/include/asm-i386/module.h
+++ b/include/asm-i386/module.h
@@ -62,18 +62,12 @@ struct mod_arch_specific
 #error unknown processor family
 #endif
 
-#ifdef CONFIG_REGPARM
-#define MODULE_REGPARM "REGPARM "
-#else
-#define MODULE_REGPARM ""
-#endif
-
 #ifdef CONFIG_4KSTACKS
 #define MODULE_STACKSIZE "4KSTACKS "
 #else
 #define MODULE_STACKSIZE ""
 #endif
 
-#define MODULE_ARCH_VERMAGIC MODULE_PROC_FAMILY MODULE_REGPARM MODULE_STACKSIZE
+#define MODULE_ARCH_VERMAGIC MODULE_PROC_FAMILY MODULE_STACKSIZE
 
 #endif /* _ASM_I386_MODULE_H */