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