1 files changed, 124 insertions, 0 deletions
diff --git a/arch/s390/boot/printk.c b/arch/s390/boot/printk.c
new file mode 100644
index 000000000000..35f18f2b936e
--- /dev/null
+++ b/arch/s390/boot/printk.c
@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/stdarg.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#include <asm/stacktrace.h>
+#include <asm/boot_data.h>
+#include <asm/lowcore.h>
+#include <asm/setup.h>
+#include <asm/sclp.h>
+#include <asm/uv.h>
+#include "boot.h"
+
+const char hex_asc[] = "0123456789abcdef";
+
+static char *as_hex(char *dst, unsigned long val, int pad)
+{
+	char *p, *end = p = dst + max(pad, (int)__fls(val | 1) / 4 + 1);
+
+	for (*p-- = 0; p >= dst; val >>= 4)
+		*p-- = hex_asc[val & 0x0f];
+	return end;
+}
+
+static char *symstart(char *p)
+{
+	while (*p)
+		p--;
+	return p + 1;
+}
+
+static noinline char *findsym(unsigned long ip, unsigned short *off, unsigned short *len)
+{
+	/* symbol entries are in a form "10000 c4 startup\0" */
+	char *a = _decompressor_syms_start;
+	char *b = _decompressor_syms_end;
+	unsigned long start;
+	unsigned long size;
+	char *pivot;
+	char *endp;
+
+	while (a < b) {
+		pivot = symstart(a + (b - a) / 2);
+		start = simple_strtoull(pivot, &endp, 16);
+		size = simple_strtoull(endp + 1, &endp, 16);
+		if (ip < start) {
+			b = pivot;
+			continue;
+		}
+		if (ip > start + size) {
+			a = pivot + strlen(pivot) + 1;
+			continue;
+		}
+		*off = ip - start;
+		*len = size;
+		return endp + 1;
+	}
+	return NULL;
+}
+
+static noinline char *strsym(void *ip)
+{
+	static char buf[64];
+	unsigned short off;
+	unsigned short len;
+	char *p;
+
+	p = findsym((unsigned long)ip, &off, &len);
+	if (p) {
+		strncpy(buf, p, sizeof(buf));
+		/* reserve 15 bytes for offset/len in symbol+0x1234/0x1234 */
+		p = buf + strnlen(buf, sizeof(buf) - 15);
+		strcpy(p, "+0x");
+		p = as_hex(p + 3, off, 0);
+		strcpy(p, "/0x");
+		as_hex(p + 3, len, 0);
+	} else {
+		as_hex(buf, (unsigned long)ip, 16);
+	}
+	return buf;
+}
+
+void boot_printk(const char *fmt, ...)
+{
+	char buf[1024] = { 0 };
+	char *end = buf + sizeof(buf) - 1; /* make sure buf is 0 terminated */
+	unsigned long pad;
+	char *p = buf;
+	va_list args;
+
+	va_start(args, fmt);
+	for (; p < end && *fmt; fmt++) {
+		if (*fmt != '%') {
+			*p++ = *fmt;
+			continue;
+		}
+		pad = isdigit(*++fmt) ? simple_strtol(fmt, (char **)&fmt, 10) : 0;
+		switch (*fmt) {
+		case 's':
+			p = buf + strlcat(buf, va_arg(args, char *), sizeof(buf));
+			break;
+		case 'p':
+			if (*++fmt != 'S')
+				goto out;
+			p = buf + strlcat(buf, strsym(va_arg(args, void *)), sizeof(buf));
+			break;
+		case 'l':
+			if (*++fmt != 'x' || end - p <= max(sizeof(long) * 2, pad))
+				goto out;
+			p = as_hex(p, va_arg(args, unsigned long), pad);
+			break;
+		case 'x':
+			if (end - p <= max(sizeof(int) * 2, pad))
+				goto out;
+			p = as_hex(p, va_arg(args, unsigned int), pad);
+			break;
+		default:
+			goto out;
+		}
+	}
+out:
+	va_end(args);
+	sclp_early_printk(buf);
+}