1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * printf.c: Internal prom library printf facility.
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
6*4882a593Smuzhiyun * Copyright (C) 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
7*4882a593Smuzhiyun * Copyright (c) 2002 Pete Zaitcev (zaitcev@yahoo.com)
8*4882a593Smuzhiyun *
9*4882a593Smuzhiyun * We used to warn all over the code: DO NOT USE prom_printf(),
10*4882a593Smuzhiyun * and yet people do. Anton's banking code was outputting banks
11*4882a593Smuzhiyun * with prom_printf for most of the 2.4 lifetime. Since an effective
12*4882a593Smuzhiyun * stick is not available, we deployed a carrot: an early printk
13*4882a593Smuzhiyun * through PROM by means of -p boot option. This ought to fix it.
14*4882a593Smuzhiyun * USE printk; if you need, deploy -p.
15*4882a593Smuzhiyun */
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun #include <linux/kernel.h>
18*4882a593Smuzhiyun #include <linux/compiler.h>
19*4882a593Smuzhiyun #include <linux/spinlock.h>
20*4882a593Smuzhiyun
21*4882a593Smuzhiyun #include <asm/openprom.h>
22*4882a593Smuzhiyun #include <asm/oplib.h>
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun #define CONSOLE_WRITE_BUF_SIZE 1024
25*4882a593Smuzhiyun
26*4882a593Smuzhiyun static char ppbuf[1024];
27*4882a593Smuzhiyun static char console_write_buf[CONSOLE_WRITE_BUF_SIZE];
28*4882a593Smuzhiyun static DEFINE_RAW_SPINLOCK(console_write_lock);
29*4882a593Smuzhiyun
prom_write(const char * buf,unsigned int n)30*4882a593Smuzhiyun void notrace prom_write(const char *buf, unsigned int n)
31*4882a593Smuzhiyun {
32*4882a593Smuzhiyun unsigned int dest_len;
33*4882a593Smuzhiyun unsigned long flags;
34*4882a593Smuzhiyun char *dest;
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun dest = console_write_buf;
37*4882a593Smuzhiyun raw_spin_lock_irqsave(&console_write_lock, flags);
38*4882a593Smuzhiyun
39*4882a593Smuzhiyun dest_len = 0;
40*4882a593Smuzhiyun while (n-- != 0) {
41*4882a593Smuzhiyun char ch = *buf++;
42*4882a593Smuzhiyun if (ch == '\n') {
43*4882a593Smuzhiyun *dest++ = '\r';
44*4882a593Smuzhiyun dest_len++;
45*4882a593Smuzhiyun }
46*4882a593Smuzhiyun *dest++ = ch;
47*4882a593Smuzhiyun dest_len++;
48*4882a593Smuzhiyun if (dest_len >= CONSOLE_WRITE_BUF_SIZE - 1) {
49*4882a593Smuzhiyun prom_console_write_buf(console_write_buf, dest_len);
50*4882a593Smuzhiyun dest = console_write_buf;
51*4882a593Smuzhiyun dest_len = 0;
52*4882a593Smuzhiyun }
53*4882a593Smuzhiyun }
54*4882a593Smuzhiyun if (dest_len)
55*4882a593Smuzhiyun prom_console_write_buf(console_write_buf, dest_len);
56*4882a593Smuzhiyun
57*4882a593Smuzhiyun raw_spin_unlock_irqrestore(&console_write_lock, flags);
58*4882a593Smuzhiyun }
59*4882a593Smuzhiyun
prom_printf(const char * fmt,...)60*4882a593Smuzhiyun void notrace prom_printf(const char *fmt, ...)
61*4882a593Smuzhiyun {
62*4882a593Smuzhiyun va_list args;
63*4882a593Smuzhiyun int i;
64*4882a593Smuzhiyun
65*4882a593Smuzhiyun va_start(args, fmt);
66*4882a593Smuzhiyun i = vscnprintf(ppbuf, sizeof(ppbuf), fmt, args);
67*4882a593Smuzhiyun va_end(args);
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun prom_write(ppbuf, i);
70*4882a593Smuzhiyun }
71