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			63 lines
		
	
	
		
			1.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			63 lines
		
	
	
		
			1.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0+
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/*
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 * Copyright (C) 1999  Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se>
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 *
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 * (C) Copyright 2000
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 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
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 */
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#include <common.h>
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#include <log.h>
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/*
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 * The exception table consists of pairs of addresses: the first is the
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 * address of an instruction that is allowed to fault, and the second is
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 * the address at which the program should continue.  No registers are
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 * modified, so it is entirely up to the continuation code to figure out
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 * what to do.
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 *
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 * All the routines below use bits of fixup code that are out of line
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 * with the main instruction path.  This means when everything is well,
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 * we don't even have to jump over them.  Further, they do not intrude
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 * on our cache or tlb entries.
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 */
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struct exception_table_entry
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{
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	unsigned long insn, fixup;
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};
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extern const struct exception_table_entry __start___ex_table[];
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extern const struct exception_table_entry __stop___ex_table[];
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static inline unsigned long
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search_one_table(const struct exception_table_entry *first,
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		 const struct exception_table_entry *last,
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		 unsigned long value)
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{
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	long diff;
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	while (first <= last) {
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		diff = first->insn - value;
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		if (diff == 0)
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			return first->fixup;
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		first++;
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	}
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	return 0;
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}
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unsigned long
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search_exception_table(unsigned long addr)
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{
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	unsigned long ret;
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	/* There is only the kernel to search.  */
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	ret = search_one_table(__start___ex_table, __stop___ex_table-1, addr);
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	/* if the serial port does not hang in exception, printf can be used */
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#if !defined(CONFIG_SYS_SERIAL_HANG_IN_EXCEPTION)
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	debug("Bus Fault @ 0x%08lx, fixup 0x%08lx\n", addr, ret);
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#endif
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	if (ret) return ret;
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	return 0;
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}
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