71 lines
		
	
	
		
			1.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			71 lines
		
	
	
		
			1.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0
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| /*
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|  * printf.c:  Internal prom library printf facility.
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|  *
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|  * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
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|  * Copyright (C) 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
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|  * Copyright (c) 2002 Pete Zaitcev (zaitcev@yahoo.com)
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|  *
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|  * We used to warn all over the code: DO NOT USE prom_printf(),
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|  * and yet people do. Anton's banking code was outputting banks
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|  * with prom_printf for most of the 2.4 lifetime. Since an effective
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|  * stick is not available, we deployed a carrot: an early printk
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|  * through PROM by means of -p boot option. This ought to fix it.
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|  * USE printk; if you need, deploy -p.
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|  */
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| 
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| #include <linux/kernel.h>
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| #include <linux/compiler.h>
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| #include <linux/spinlock.h>
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| 
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| #include <asm/openprom.h>
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| #include <asm/oplib.h>
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| 
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| #define CONSOLE_WRITE_BUF_SIZE	1024
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| 
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| static char ppbuf[1024];
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| static char console_write_buf[CONSOLE_WRITE_BUF_SIZE];
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| static DEFINE_RAW_SPINLOCK(console_write_lock);
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| 
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| void notrace prom_write(const char *buf, unsigned int n)
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| {
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| 	unsigned int dest_len;
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| 	unsigned long flags;
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| 	char *dest;
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| 
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| 	dest = console_write_buf;
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| 	raw_spin_lock_irqsave(&console_write_lock, flags);
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| 
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| 	dest_len = 0;
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| 	while (n-- != 0) {
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| 		char ch = *buf++;
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| 		if (ch == '\n') {
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| 			*dest++ = '\r';
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| 			dest_len++;
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| 		}
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| 		*dest++ = ch;
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| 		dest_len++;
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| 		if (dest_len >= CONSOLE_WRITE_BUF_SIZE - 1) {
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| 			prom_console_write_buf(console_write_buf, dest_len);
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| 			dest = console_write_buf;
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| 			dest_len = 0;
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| 		}
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| 	}
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| 	if (dest_len)
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| 		prom_console_write_buf(console_write_buf, dest_len);
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| 
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| 	raw_spin_unlock_irqrestore(&console_write_lock, flags);
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| }
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| 
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| void notrace prom_printf(const char *fmt, ...)
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| {
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| 	va_list args;
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| 	int i;
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| 
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| 	va_start(args, fmt);
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| 	i = vscnprintf(ppbuf, sizeof(ppbuf), fmt, args);
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| 	va_end(args);
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| 
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| 	prom_write(ppbuf, i);
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| }
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