1 files changed, 138 insertions, 0 deletions
diff --git a/arch/s390/boot/alternative.c b/arch/s390/boot/alternative.c
new file mode 100644
index 000000000000..19ea7934b918
--- /dev/null
+++ b/arch/s390/boot/alternative.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0
+#define boot_fmt(fmt)	"alt: " fmt
+#include "boot.h"
+
+#define a_debug		boot_debug
+
+#include "../kernel/alternative.c"
+
+static void alt_debug_all(int type)
+{
+	int i;
+
+	switch (type) {
+	case ALT_TYPE_FACILITY:
+		for (i = 0; i < ARRAY_SIZE(alt_debug.facilities); i++)
+			alt_debug.facilities[i] = -1UL;
+		break;
+	case ALT_TYPE_FEATURE:
+		for (i = 0; i < ARRAY_SIZE(alt_debug.mfeatures); i++)
+			alt_debug.mfeatures[i] = -1UL;
+		break;
+	case ALT_TYPE_SPEC:
+		alt_debug.spec = 1;
+		break;
+	}
+}
+
+static void alt_debug_modify(int type, unsigned int nr, bool clear)
+{
+	switch (type) {
+	case ALT_TYPE_FACILITY:
+		if (clear)
+			__clear_facility(nr, alt_debug.facilities);
+		else
+			__set_facility(nr, alt_debug.facilities);
+		break;
+	case ALT_TYPE_FEATURE:
+		if (clear)
+			__clear_machine_feature(nr, alt_debug.mfeatures);
+		else
+			__set_machine_feature(nr, alt_debug.mfeatures);
+		break;
+	}
+}
+
+static char *alt_debug_parse(int type, char *str)
+{
+	unsigned long val, endval;
+	char *endp;
+	bool clear;
+	int i;
+
+	if (*str == ':') {
+		str++;
+	} else {
+		alt_debug_all(type);
+		return str;
+	}
+	clear = false;
+	if (*str == '!') {
+		alt_debug_all(type);
+		clear = true;
+		str++;
+	}
+	while (*str) {
+		val = simple_strtoull(str, &endp, 0);
+		if (str == endp)
+			break;
+		str = endp;
+		if (*str == '-') {
+			str++;
+			endval = simple_strtoull(str, &endp, 0);
+			if (str == endp)
+				break;
+			str = endp;
+			while (val <= endval) {
+				alt_debug_modify(type, val, clear);
+				val++;
+			}
+		} else {
+			alt_debug_modify(type, val, clear);
+		}
+		if (*str != ',')
+			break;
+		str++;
+	}
+	return str;
+}
+
+/*
+ * Use debug-alternative command line parameter for debugging:
+ * "debug-alternative"
+ *  -> print debug message for every single alternative
+ *
+ * "debug-alternative=0;2"
+ * -> print debug message for all alternatives with type 0 and 2
+ *
+ * "debug-alternative=0:0-7"
+ * -> print debug message for all alternatives with type 0 and with
+ *    facility numbers within the range of 0-7
+ *    (if type 0 is ALT_TYPE_FACILITY)
+ *
+ * "debug-alternative=0:!8;1"
+ * -> print debug message for all alternatives with type 0, for all
+ *    facility number, except facility 8, and in addition print all
+ *    alternatives with type 1
+ */
+void alt_debug_setup(char *str)
+{
+	unsigned long type;
+	char *endp;
+	int i;
+
+	if (!str) {
+		alt_debug_all(ALT_TYPE_FACILITY);
+		alt_debug_all(ALT_TYPE_FEATURE);
+		alt_debug_all(ALT_TYPE_SPEC);
+		return;
+	}
+	while (*str) {
+		type = simple_strtoull(str, &endp, 0);
+		if (str == endp)
+			break;
+		str = endp;
+		switch (type) {
+		case ALT_TYPE_FACILITY:
+		case ALT_TYPE_FEATURE:
+			str = alt_debug_parse(type, str);
+			break;
+		case ALT_TYPE_SPEC:
+			alt_debug_all(ALT_TYPE_SPEC);
+			break;
+		}
+		if (*str != ';')
+			break;
+		str++;
+	}
+}