x86: fix UML and -regparm=3

introduce the "asmregparm" calling convention: for functions
implemented in assembly with a fixed regparm input parameters
calling convention.

mark the semaphore and rwsem slowpath functions with that.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/include/asm-x86/linkage.h b/include/asm-x86/linkage.h
index 5a4c959..31739c7 100644
--- a/include/asm-x86/linkage.h
+++ b/include/asm-x86/linkage.h
@@ -9,6 +9,11 @@
 #ifdef CONFIG_X86_32
 #define asmlinkage CPP_ASMLINKAGE __attribute__((regparm(0)))
 #define prevent_tail_call(ret) __asm__ ("" : "=r" (ret) : "0" (ret))
+/*
+ * For 32-bit UML - mark functions implemented in assembly that use
+ * regparm input parameters:
+ */
+#define asmregparm __attribute__((regparm(3)))
 #endif
 
 #ifdef CONFIG_X86_ALIGNMENT_16