Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * printf.c: Internal prom library printf facility. | |
4 | * | |
5 | * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu) | |
6 | * Copyright (C) 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz) | |
7 | * Copyright (c) 2002 Pete Zaitcev (zaitcev@yahoo.com) | |
8 | * | |
9 | * We used to warn all over the code: DO NOT USE prom_printf(), | |
10 | * and yet people do. Anton's banking code was outputting banks | |
11 | * with prom_printf for most of the 2.4 lifetime. Since an effective | |
12 | * stick is not available, we deployed a carrot: an early printk | |
13 | * through PROM by means of -p boot option. This ought to fix it. | |
14 | * USE printk; if you need, deploy -p. | |
15 | */ | |
16 | ||
17 | #include <linux/kernel.h> | |
bd4352ca | 18 | #include <linux/compiler.h> |
595a251c | 19 | #include <linux/spinlock.h> |
1da177e4 LT |
20 | |
21 | #include <asm/openprom.h> | |
22 | #include <asm/oplib.h> | |
23 | ||
595a251c DM |
24 | #define CONSOLE_WRITE_BUF_SIZE 1024 |
25 | ||
1da177e4 | 26 | static char ppbuf[1024]; |
595a251c DM |
27 | static char console_write_buf[CONSOLE_WRITE_BUF_SIZE]; |
28 | static DEFINE_RAW_SPINLOCK(console_write_lock); | |
1da177e4 | 29 | |
bd4352ca | 30 | void notrace prom_write(const char *buf, unsigned int n) |
1da177e4 | 31 | { |
595a251c DM |
32 | unsigned int dest_len; |
33 | unsigned long flags; | |
34 | char *dest; | |
35 | ||
36 | dest = console_write_buf; | |
37 | raw_spin_lock_irqsave(&console_write_lock, flags); | |
38 | ||
39 | dest_len = 0; | |
e62cac1f | 40 | while (n-- != 0) { |
595a251c | 41 | char ch = *buf++; |
e62cac1f | 42 | if (ch == '\n') { |
595a251c DM |
43 | *dest++ = '\r'; |
44 | dest_len++; | |
45 | } | |
46 | *dest++ = ch; | |
47 | dest_len++; | |
48 | if (dest_len >= CONSOLE_WRITE_BUF_SIZE - 1) { | |
49 | prom_console_write_buf(console_write_buf, dest_len); | |
50 | dest = console_write_buf; | |
51 | dest_len = 0; | |
e62cac1f | 52 | } |
1da177e4 | 53 | } |
595a251c DM |
54 | if (dest_len) |
55 | prom_console_write_buf(console_write_buf, dest_len); | |
56 | ||
57 | raw_spin_unlock_irqrestore(&console_write_lock, flags); | |
1da177e4 LT |
58 | } |
59 | ||
bd4352ca | 60 | void notrace prom_printf(const char *fmt, ...) |
1da177e4 LT |
61 | { |
62 | va_list args; | |
63 | int i; | |
64 | ||
65 | va_start(args, fmt); | |
66 | i = vscnprintf(ppbuf, sizeof(ppbuf), fmt, args); | |
67 | va_end(args); | |
68 | ||
69 | prom_write(ppbuf, i); | |
70 | } |