[kvm-unit-tests PATCH v2 1/7] s390x: snippets: asm: Add a macro to write an exception PSW

[Janosch Frank <frankja@linux.ibm.com>]

Setting exception new PSWs is commonly needed so let's add a macro for
that.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Nico Boehr <nrb@linux.ibm.com>
---
 s390x/snippets/asm/macros.S              | 28 ++++++++++++++++++++++++
 s390x/snippets/asm/snippet-pv-diag-288.S |  4 ++--
 s390x/snippets/asm/snippet-pv-diag-500.S |  6 ++---
 3 files changed, 32 insertions(+), 6 deletions(-)
 create mode 100644 s390x/snippets/asm/macros.S

diff --git a/s390x/snippets/asm/macros.S b/s390x/snippets/asm/macros.S
new file mode 100644
index 00000000..667fb6dc
--- /dev/null
+++ b/s390x/snippets/asm/macros.S
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Commonly used assembly macros
+ *
+ * Copyright (c) 2022 IBM Corp
+ *
+ * Authors:
+ *  Janosch Frank <frankja@linux.ibm.com>
+ */
+#include <asm/asm-offsets.h>
+
+/*
+ * Writes a PSW to addr_psw, useful for exception PSWs in lowcore
+ *
+ * reg is the scratch register used for temporary storage, it's NOT restored
+ * The psw address part is defined via psw_new_addr
+ * The psw mask part is always 64 bit
+ */
+.macro SET_PSW_NEW_ADDR reg, psw_new_addr, addr_psw
+larl	\reg, psw_mask_64
+stg	\reg, \addr_psw
+larl	\reg, \psw_new_addr
+stg	\reg, \addr_psw + 8
+.endm
+
+.section .rodata
+psw_mask_64:
+	.quad	0x0000000180000000
diff --git a/s390x/snippets/asm/snippet-pv-diag-288.S b/s390x/snippets/asm/snippet-pv-diag-288.S
index aaee3cd1..63f2113b 100644
--- a/s390x/snippets/asm/snippet-pv-diag-288.S
+++ b/s390x/snippets/asm/snippet-pv-diag-288.S
@@ -8,6 +8,7 @@
  *  Janosch Frank <frankja@linux.ibm.com>
  */
 #include <asm/asm-offsets.h>
+#include "macros.S"
 .section .text
 
 /* Clean and pre-load registers that are used for diag 288 */
@@ -19,8 +20,7 @@ lghi	%r1, 2
 lghi	%r2, 3
 
 /* Let's jump to the pgm exit label on a PGM */
-larl	%r4, exit_pgm
-stg     %r4, GEN_LC_PGM_NEW_PSW + 8
+SET_PSW_NEW_ADDR 4, exit_pgm, GEN_LC_PGM_NEW_PSW
 
 /* Execute the diag288 */
 diag	%r0, %r2, 0x288
diff --git a/s390x/snippets/asm/snippet-pv-diag-500.S b/s390x/snippets/asm/snippet-pv-diag-500.S
index 8dd66bd9..f4d75388 100644
--- a/s390x/snippets/asm/snippet-pv-diag-500.S
+++ b/s390x/snippets/asm/snippet-pv-diag-500.S
@@ -8,6 +8,7 @@
  *  Janosch Frank <frankja@linux.ibm.com>
  */
 #include <asm/asm-offsets.h>
+#include "macros.S"
 .section .text
 
 /* Clean and pre-load registers that are used for diag 500 */
@@ -21,10 +22,7 @@ lghi	%r3, 3
 lghi	%r4, 4
 
 /* Let's jump to the next label on a PGM */
-xgr	%r5, %r5
-stg	%r5, GEN_LC_PGM_NEW_PSW
-larl	%r5, next
-stg	%r5, GEN_LC_PGM_NEW_PSW + 8
+SET_PSW_NEW_ADDR 5, next, GEN_LC_PGM_NEW_PSW
 
 /* Execute the diag500 */
 diag	0, 0, 0x500
-- 
2.34.1