// 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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#include <linux/kernel.h>
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#include <linux/compiler.h>
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#include <linux/spinlock.h>
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#include <asm/openprom.h>
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#include <asm/oplib.h>
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#define CONSOLE_WRITE_BUF_SIZE 1024
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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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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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dest = console_write_buf;
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raw_spin_lock_irqsave(&console_write_lock, flags);
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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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raw_spin_unlock_irqrestore(&console_write_lock, flags);
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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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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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prom_write(ppbuf, i);
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}
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