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-rw-r--r--arch/s390/boot/printk.c124
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);
+}