Tom Rini | 83d290c | 2018-05-06 17:58:06 -0400 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0+ |
wdenk | fe8c280 | 2002-11-03 00:38:21 +0000 | [diff] [blame] | 2 | /* |
| 3 | * Copyright (C) 1999 Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se> |
| 4 | * |
| 5 | * (C) Copyright 2000 |
| 6 | * Wolfgang Denk, DENX Software Engineering, wd@denx.de. |
wdenk | fe8c280 | 2002-11-03 00:38:21 +0000 | [diff] [blame] | 7 | */ |
| 8 | #include <common.h> |
Simon Glass | f7ae49f | 2020-05-10 11:40:05 -0600 | [diff] [blame] | 9 | #include <log.h> |
wdenk | fe8c280 | 2002-11-03 00:38:21 +0000 | [diff] [blame] | 10 | |
| 11 | /* |
| 12 | * The exception table consists of pairs of addresses: the first is the |
| 13 | * address of an instruction that is allowed to fault, and the second is |
| 14 | * the address at which the program should continue. No registers are |
| 15 | * modified, so it is entirely up to the continuation code to figure out |
| 16 | * what to do. |
| 17 | * |
| 18 | * All the routines below use bits of fixup code that are out of line |
| 19 | * with the main instruction path. This means when everything is well, |
| 20 | * we don't even have to jump over them. Further, they do not intrude |
| 21 | * on our cache or tlb entries. |
| 22 | */ |
| 23 | |
| 24 | struct exception_table_entry |
| 25 | { |
| 26 | unsigned long insn, fixup; |
| 27 | }; |
| 28 | |
| 29 | extern const struct exception_table_entry __start___ex_table[]; |
| 30 | extern const struct exception_table_entry __stop___ex_table[]; |
| 31 | |
| 32 | static inline unsigned long |
| 33 | search_one_table(const struct exception_table_entry *first, |
| 34 | const struct exception_table_entry *last, |
| 35 | unsigned long value) |
| 36 | { |
Zang Roy-r61911 | 1b305bd | 2007-05-09 08:10:57 +0800 | [diff] [blame] | 37 | long diff; |
Peter Tyser | e6b05e7 | 2009-09-21 11:20:29 -0500 | [diff] [blame] | 38 | while (first <= last) { |
| 39 | diff = first->insn - value; |
| 40 | if (diff == 0) |
| 41 | return first->fixup; |
| 42 | first++; |
wdenk | 8bde7f7 | 2003-06-27 21:31:46 +0000 | [diff] [blame] | 43 | } |
Peter Tyser | e6b05e7 | 2009-09-21 11:20:29 -0500 | [diff] [blame] | 44 | |
wdenk | 8bde7f7 | 2003-06-27 21:31:46 +0000 | [diff] [blame] | 45 | return 0; |
wdenk | fe8c280 | 2002-11-03 00:38:21 +0000 | [diff] [blame] | 46 | } |
| 47 | |
wdenk | fe8c280 | 2002-11-03 00:38:21 +0000 | [diff] [blame] | 48 | unsigned long |
| 49 | search_exception_table(unsigned long addr) |
| 50 | { |
| 51 | unsigned long ret; |
| 52 | |
| 53 | /* There is only the kernel to search. */ |
| 54 | ret = search_one_table(__start___ex_table, __stop___ex_table-1, addr); |
roy zang | c9c1eee | 2006-12-01 19:01:25 +0800 | [diff] [blame] | 55 | /* if the serial port does not hang in exception, printf can be used */ |
Jean-Christophe PLAGNIOL-VILLARD | 6d0f6bc | 2008-10-16 15:01:15 +0200 | [diff] [blame] | 56 | #if !defined(CONFIG_SYS_SERIAL_HANG_IN_EXCEPTION) |
Kim Phillips | fe44f45 | 2012-10-29 13:34:28 +0000 | [diff] [blame] | 57 | debug("Bus Fault @ 0x%08lx, fixup 0x%08lx\n", addr, ret); |
roy zang | 4c52783 | 2006-11-02 18:49:51 +0800 | [diff] [blame] | 58 | #endif |
wdenk | fe8c280 | 2002-11-03 00:38:21 +0000 | [diff] [blame] | 59 | if (ret) return ret; |
| 60 | |
| 61 | return 0; |
| 62 | } |