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