1// SPDX-License-Identifier: GPL-2.0
  2#include <linux/kernel.h>
  3#include <linux/stdarg.h>
  4#include <linux/string.h>
  5#include <linux/ctype.h>
  6#include <asm/stacktrace.h>
  7#include <asm/boot_data.h>
  8#include <asm/lowcore.h>
  9#include <asm/setup.h>
 10#include <asm/sclp.h>
 11#include <asm/uv.h>
 12#include "boot.h"
 13
 14const char hex_asc[] = "0123456789abcdef";
 15
 16static char *as_hex(char *dst, unsigned long val, int pad)
 17{
 18	char *p, *end = p = dst + max(pad, (int)__fls(val | 1) / 4 + 1);
 19
 20	for (*p-- = 0; p >= dst; val >>= 4)
 21		*p-- = hex_asc[val & 0x0f];
 22	return end;
 23}
 24
 25static char *symstart(char *p)
 26{
 27	while (*p)
 28		p--;
 29	return p + 1;
 30}
 31
 32static noinline char *findsym(unsigned long ip, unsigned short *off, unsigned short *len)
 33{
 34	/* symbol entries are in a form "10000 c4 startup\0" */
 35	char *a = _decompressor_syms_start;
 36	char *b = _decompressor_syms_end;
 37	unsigned long start;
 38	unsigned long size;
 39	char *pivot;
 40	char *endp;
 41
 42	while (a < b) {
 43		pivot = symstart(a + (b - a) / 2);
 44		start = simple_strtoull(pivot, &endp, 16);
 45		size = simple_strtoull(endp + 1, &endp, 16);
 46		if (ip < start) {
 47			b = pivot;
 48			continue;
 49		}
 50		if (ip > start + size) {
 51			a = pivot + strlen(pivot) + 1;
 52			continue;
 53		}
 54		*off = ip - start;
 55		*len = size;
 56		return endp + 1;
 57	}
 58	return NULL;
 59}
 60
 61static noinline char *strsym(void *ip)
 62{
 63	static char buf[64];
 64	unsigned short off;
 65	unsigned short len;
 66	char *p;
 67
 68	p = findsym((unsigned long)ip, &off, &len);
 69	if (p) {
 70		strncpy(buf, p, sizeof(buf));
 71		/* reserve 15 bytes for offset/len in symbol+0x1234/0x1234 */
 72		p = buf + strnlen(buf, sizeof(buf) - 15);
 73		strcpy(p, "+0x");
 74		p = as_hex(p + 3, off, 0);
 75		strcpy(p, "/0x");
 76		as_hex(p + 3, len, 0);
 77	} else {
 78		as_hex(buf, (unsigned long)ip, 16);
 79	}
 80	return buf;
 81}
 82
 83void boot_printk(const char *fmt, ...)
 84{
 85	char buf[1024] = { 0 };
 86	char *end = buf + sizeof(buf) - 1; /* make sure buf is 0 terminated */
 87	unsigned long pad;
 88	char *p = buf;
 89	va_list args;
 90
 91	va_start(args, fmt);
 92	for (; p < end && *fmt; fmt++) {
 93		if (*fmt != '%') {
 94			*p++ = *fmt;
 95			continue;
 96		}
 97		pad = isdigit(*++fmt) ? simple_strtol(fmt, (char **)&fmt, 10) : 0;
 98		switch (*fmt) {
 99		case 's':
100			p = buf + strlcat(buf, va_arg(args, char *), sizeof(buf));
101			break;
102		case 'p':
103			if (*++fmt != 'S')
104				goto out;
105			p = buf + strlcat(buf, strsym(va_arg(args, void *)), sizeof(buf));
106			break;
107		case 'l':
108			if (*++fmt != 'x' || end - p <= max(sizeof(long) * 2, pad))
109				goto out;
110			p = as_hex(p, va_arg(args, unsigned long), pad);
111			break;
112		case 'x':
113			if (end - p <= max(sizeof(int) * 2, pad))
114				goto out;
115			p = as_hex(p, va_arg(args, unsigned int), pad);
116			break;
117		default:
118			goto out;
119		}
120	}
121out:
122	va_end(args);
123	sclp_early_printk(buf);
124}