s390: move nobp parameter functions to nospec-branch.c

Keep the code for the nobp parameter handling with the code for
expolines. Both are related to the spectre v2 mitigation.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/arch/s390/kernel/nospec-branch.c b/arch/s390/kernel/nospec-branch.c
index 9aff72d3abda..69ce00d02d1b 100644
--- a/arch/s390/kernel/nospec-branch.c
+++ b/arch/s390/kernel/nospec-branch.c
@@ -2,6 +2,31 @@
 #include <linux/module.h>
 #include <asm/nospec-branch.h>
 
+static int __init nobp_setup_early(char *str)
+{
+	bool enabled;
+	int rc;
+
+	rc = kstrtobool(str, &enabled);
+	if (rc)
+		return rc;
+	if (enabled && test_facility(82))
+		__set_facility(82, S390_lowcore.alt_stfle_fac_list);
+	else
+		__clear_facility(82, S390_lowcore.alt_stfle_fac_list);
+	return 0;
+}
+early_param("nobp", nobp_setup_early);
+
+static int __init nospec_setup_early(char *str)
+{
+	__clear_facility(82, S390_lowcore.alt_stfle_fac_list);
+	return 0;
+}
+early_param("nospec", nospec_setup_early);
+
+#ifdef CONFIG_EXPOLINE
+
 int nospec_call_disable = IS_ENABLED(CONFIG_EXPOLINE_OFF);
 int nospec_return_disable = !IS_ENABLED(CONFIG_EXPOLINE_FULL);
 
@@ -98,3 +123,5 @@ void __init nospec_init_branches(void)
 	nospec_call_revert(__nospec_call_start, __nospec_call_end);
 	nospec_return_revert(__nospec_return_start, __nospec_return_end);
 }
+
+#endif /* CONFIG_EXPOLINE */