Subject: [PATCH v7 24/28] powerpc: Test prefixed code patching

From: Jordan Niethe <[email-masked]>
Date: Fri, 1 May 2020 13:42:16 +1000

Expand the code-patching self-tests to includes tests for patching
prefixed instructions.

Signed-off-by: Jordan Niethe <[email-masked]>
---
v6: New to series
---
 arch/powerpc/lib/Makefile             |  2 +-
 arch/powerpc/lib/code-patching.c      | 21 +++++++++++++++++++++
 arch/powerpc/lib/test_code-patching.S | 19 +++++++++++++++++++
 3 files changed, 41 insertions(+), 1 deletion(-)
 create mode 100644 arch/powerpc/lib/test_code-patching.S

diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index 546591848219..5e994cda8e40 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -16,7 +16,7 @@ CFLAGS_code-patching.o += -DDISABLE_BRANCH_PROFILING
 CFLAGS_feature-fixups.o += -DDISABLE_BRANCH_PROFILING
 endif
 
-obj-y += alloc.o code-patching.o feature-fixups.o pmem.o inst.o
+obj-y += alloc.o code-patching.o feature-fixups.o pmem.o inst.o test_code-patching.o
 
 ifndef CONFIG_KASAN
 obj-y	+=	string.o memcmp_$(BITS).o
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index b32fa707725e..7107c6d01261 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -699,6 +699,24 @@ static void __init test_translate_branch(void)
 	vfree(buf);
 }
 
+#ifdef __powerpc64__
+static void __init test_prefixed_patching(void)
+{
+	extern unsigned int code_patching_test1[];
+	extern unsigned int code_patching_test1_expected[];
+	extern unsigned int end_code_patching_test1[];
+
+	__patch_instruction((struct ppc_inst *)code_patching_test1,
+			    ppc_inst_prefix(1 << 26, 0x00000000),
+			    (struct ppc_inst *)code_patching_test1);
+
+	check(!memcmp(code_patching_test1,
+		      code_patching_test1_expected,
+		      sizeof(unsigned int) *
+		      (end_code_patching_test1 - code_patching_test1)));
+}
+#endif
+
 static int __init test_code_patching(void)
 {
 	printk(KERN_DEBUG "Running code patching self-tests ...\n");
@@ -707,6 +725,9 @@ static int __init test_code_patching(void)
 	test_branch_bform();
 	test_create_function_call();
 	test_translate_branch();
+#ifdef __powerpc64__
+	test_prefixed_patching();
+#endif
 
 	return 0;
 }
diff --git a/arch/powerpc/lib/test_code-patching.S b/arch/powerpc/lib/test_code-patching.S
new file mode 100644
index 000000000000..91aab208a804
--- /dev/null
+++ b/arch/powerpc/lib/test_code-patching.S
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020 IBM Corporation
+ */
+
+	.text
+
+#define globl(x)		\
+	.globl x;	\
+x:
+
+globl(code_patching_test1)
+	nop
+	nop
+globl(end_code_patching_test1)
+
+globl(code_patching_test1_expected)
+	.long 1 << 26
+	.long 0x0000000
-- 
2.17.1