[PATCH v3 10/23] s390: Add range check asm macro

[Steffen Eiden <seiden@linux.ibm.com>]

The range check macro turns cryptic assembler errors into an easy to
understand error if e.g. someone mistypes an input value in an asm
macro.

Add an asm macro that verifies that a given input value is in a specific
range. Add macros which check for ranges often used when creating
instructions. While at it, add a range check for the register numbers in
the GR_NUM and VX_NUM macro.

Co-developed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
 arch/s390/include/asm/insn-common-asm.h | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/arch/s390/include/asm/insn-common-asm.h b/arch/s390/include/asm/insn-common-asm.h
index fd9b3cacb7c5..f3f10f2c92bb 100644
--- a/arch/s390/include/asm/insn-common-asm.h
+++ b/arch/s390/include/asm/insn-common-asm.h
@@ -9,6 +9,32 @@
 
 #ifdef __ASSEMBLER__
 
+.macro	RANGECHECK	min max val
+	.if (\val < \min) || (\val > \max)
+	.error "operand out of range (\val is not between \min and \max)"
+	.endif
+.endm
+
+.macro	ASSERT_U16	val
+	RANGECHECK 0, 65535, \val
+.endm
+
+.macro	ASSERT_S16	val
+	RANGECHECK -32768, 32767, \val
+.endm
+
+.macro	ASSERT_U8	val
+	RANGECHECK 0, 255, \val
+.endm
+
+.macro	ASSERT_U4	val
+	RANGECHECK 0, 15, \val
+.endm
+
+.macro	ASSERT_U5	val
+	RANGECHECK 0, 31, \val
+.endm
+
 /*
  * GR_NUM - Retrieve general-purpose register number
  *
@@ -24,6 +50,7 @@
 	.endr
 	.if \opd == 255
 		\opd = \gr
+		ASSERT_U4	\opd
 	.endif
 .endm
 
@@ -46,6 +73,7 @@
 	.endr
 	.if \opd == 255
 		\opd = \vxr
+		ASSERT_U5	\opd
 	.endif
 .endm
 

-- 
2.56.0