From 53255c9a4dade6ff2162121430d13aaadb38a69c Mon Sep 17 00:00:00 2001
From: Heiko Carstens <heiko.carstens@de.ibm.com>
Date: Tue, 7 Oct 2014 15:45:10 +0200
Subject: s390/ftrace: remove 31 bit ftrace support

31 bit and 64 bit diverge more and more and it is rather painful
to keep both parts running.
To make things simpler just remove the 31 bit support which nobody
uses anyway.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 arch/s390/kernel/mcount.S | 87 +++++++++++++++++++++++++++--------------------
 1 file changed, 50 insertions(+), 37 deletions(-)

(limited to 'arch/s390/kernel/mcount.S')

diff --git a/arch/s390/kernel/mcount.S b/arch/s390/kernel/mcount.S
index be6dbd9a81a7..07abe8d464d4 100644
--- a/arch/s390/kernel/mcount.S
+++ b/arch/s390/kernel/mcount.S
@@ -8,60 +8,73 @@
 #include <linux/linkage.h>
 #include <asm/asm-offsets.h>
 #include <asm/ftrace.h>
+#include <asm/ptrace.h>
 
 	.section .kprobes.text, "ax"
 
 ENTRY(ftrace_stub)
 	br	%r14
 
+#define STACK_FRAME_SIZE  (STACK_FRAME_OVERHEAD + __PT_SIZE)
+#define STACK_PTREGS	  (STACK_FRAME_OVERHEAD)
+#define STACK_PTREGS_GPRS (STACK_PTREGS + __PT_GPRS)
+#define STACK_PTREGS_PSW  (STACK_PTREGS + __PT_PSW)
+
 ENTRY(_mcount)
 	br	%r14
 
 ENTRY(ftrace_caller)
-	stm	%r2,%r5,16(%r15)
-	bras	%r1,1f
-0:	.long	ftrace_trace_function
-1:	st	%r14,56(%r15)
-	lr	%r0,%r15
-	ahi	%r15,-96
-	l	%r3,100(%r15)
-	la	%r2,0(%r14)
-	st	%r0,__SF_BACKCHAIN(%r15)
-	la	%r3,0(%r3)
-	ahi	%r2,-MCOUNT_INSN_SIZE
-	l	%r14,0b-0b(%r1)
-	l	%r14,0(%r14)
-	basr	%r14,%r14
+	.globl	ftrace_regs_caller
+	.set	ftrace_regs_caller,ftrace_caller
+	lgr	%r1,%r15
+	aghi	%r15,-STACK_FRAME_SIZE
+	stg	%r1,__SF_BACKCHAIN(%r15)
+	stg	%r1,(STACK_PTREGS_GPRS+15*8)(%r15)
+	stg	%r0,(STACK_PTREGS_PSW+8)(%r15)
+	stmg	%r2,%r14,(STACK_PTREGS_GPRS+2*8)(%r15)
+#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
+	aghik	%r2,%r0,-MCOUNT_INSN_SIZE
+	lgrl	%r4,function_trace_op
+	lgrl	%r1,ftrace_trace_function
+#else
+	lgr	%r2,%r0
+	aghi	%r2,-MCOUNT_INSN_SIZE
+	larl	%r4,function_trace_op
+	lg	%r4,0(%r4)
+	larl	%r1,ftrace_trace_function
+	lg	%r1,0(%r1)
+#endif
+	lgr	%r3,%r14
+	la	%r5,STACK_PTREGS(%r15)
+	basr	%r14,%r1
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
-	l	%r2,100(%r15)
-	l	%r3,152(%r15)
-ENTRY(ftrace_graph_caller)
-# The bras instruction gets runtime patched to call prepare_ftrace_return.
+# The j instruction gets runtime patched to a nop instruction.
 # See ftrace_enable_ftrace_graph_caller. The patched instruction is:
-#	bras	%r14,prepare_ftrace_return
-	bras	%r14,0f
-0:	st	%r2,100(%r15)
+#	j	.+4
+ENTRY(ftrace_graph_caller)
+	j	ftrace_graph_caller_end
+	lg	%r2,(STACK_PTREGS_GPRS+14*8)(%r15)
+	lg	%r3,(STACK_PTREGS_PSW+8)(%r15)
+	brasl	%r14,prepare_ftrace_return
+	stg	%r2,(STACK_PTREGS_GPRS+14*8)(%r15)
+ftrace_graph_caller_end:
+	.globl	ftrace_graph_caller_end
 #endif
-	ahi	%r15,96
-	l	%r14,56(%r15)
-	lm	%r2,%r5,16(%r15)
-	br	%r14
+	lg	%r1,(STACK_PTREGS_PSW+8)(%r15)
+	lmg	%r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15)
+	br	%r1
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 
 ENTRY(return_to_handler)
-	stm	%r2,%r5,16(%r15)
-	st	%r14,56(%r15)
-	lr	%r0,%r15
-	ahi	%r15,-96
-	st	%r0,__SF_BACKCHAIN(%r15)
-	bras	%r1,0f
-	.long	ftrace_return_to_handler
-0:	l	%r2,0b-0b(%r1)
-	basr	%r14,%r2
-	lr	%r14,%r2
-	ahi	%r15,96
-	lm	%r2,%r5,16(%r15)
+	stmg	%r2,%r5,32(%r15)
+	lgr	%r1,%r15
+	aghi	%r15,-STACK_FRAME_OVERHEAD
+	stg	%r1,__SF_BACKCHAIN(%r15)
+	brasl	%r14,ftrace_return_to_handler
+	aghi	%r15,STACK_FRAME_OVERHEAD
+	lgr	%r14,%r2
+	lmg	%r2,%r5,32(%r15)
 	br	%r14
 
 #endif
-- 
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