1*a47a12beSStefan Roese /* 2*a47a12beSStefan Roese * Copyright (C) 1999 Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se> 3*a47a12beSStefan Roese * 4*a47a12beSStefan Roese * (C) Copyright 2000 5*a47a12beSStefan Roese * Wolfgang Denk, DENX Software Engineering, wd@denx.de. 6*a47a12beSStefan Roese * 7*a47a12beSStefan Roese * See file CREDITS for list of people who contributed to this 8*a47a12beSStefan Roese * project. 9*a47a12beSStefan Roese * 10*a47a12beSStefan Roese * This program is free software; you can redistribute it and/or 11*a47a12beSStefan Roese * modify it under the terms of the GNU General Public License as 12*a47a12beSStefan Roese * published by the Free Software Foundation; either version 2 of 13*a47a12beSStefan Roese * the License, or (at your option) any later version. 14*a47a12beSStefan Roese * 15*a47a12beSStefan Roese * This program is distributed in the hope that it will be useful, 16*a47a12beSStefan Roese * but WITHOUT ANY WARRANTY; without even the implied warranty of 17*a47a12beSStefan Roese * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18*a47a12beSStefan Roese * GNU General Public License for more details. 19*a47a12beSStefan Roese * 20*a47a12beSStefan Roese * You should have received a copy of the GNU General Public License 21*a47a12beSStefan Roese * along with this program; if not, write to the Free Software 22*a47a12beSStefan Roese * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 23*a47a12beSStefan Roese * MA 02111-1307 USA 24*a47a12beSStefan Roese */ 25*a47a12beSStefan Roese #include <common.h> 26*a47a12beSStefan Roese 27*a47a12beSStefan Roese /* 28*a47a12beSStefan Roese * The exception table consists of pairs of addresses: the first is the 29*a47a12beSStefan Roese * address of an instruction that is allowed to fault, and the second is 30*a47a12beSStefan Roese * the address at which the program should continue. No registers are 31*a47a12beSStefan Roese * modified, so it is entirely up to the continuation code to figure out 32*a47a12beSStefan Roese * what to do. 33*a47a12beSStefan Roese * 34*a47a12beSStefan Roese * All the routines below use bits of fixup code that are out of line 35*a47a12beSStefan Roese * with the main instruction path. This means when everything is well, 36*a47a12beSStefan Roese * we don't even have to jump over them. Further, they do not intrude 37*a47a12beSStefan Roese * on our cache or tlb entries. 38*a47a12beSStefan Roese */ 39*a47a12beSStefan Roese 40*a47a12beSStefan Roese DECLARE_GLOBAL_DATA_PTR; 41*a47a12beSStefan Roese 42*a47a12beSStefan Roese struct exception_table_entry 43*a47a12beSStefan Roese { 44*a47a12beSStefan Roese unsigned long insn, fixup; 45*a47a12beSStefan Roese }; 46*a47a12beSStefan Roese 47*a47a12beSStefan Roese extern const struct exception_table_entry __start___ex_table[]; 48*a47a12beSStefan Roese extern const struct exception_table_entry __stop___ex_table[]; 49*a47a12beSStefan Roese 50*a47a12beSStefan Roese static inline unsigned long 51*a47a12beSStefan Roese search_one_table(const struct exception_table_entry *first, 52*a47a12beSStefan Roese const struct exception_table_entry *last, 53*a47a12beSStefan Roese unsigned long value) 54*a47a12beSStefan Roese { 55*a47a12beSStefan Roese long diff; 56*a47a12beSStefan Roese while (first <= last) { 57*a47a12beSStefan Roese diff = first->insn - value; 58*a47a12beSStefan Roese if (diff == 0) 59*a47a12beSStefan Roese return first->fixup; 60*a47a12beSStefan Roese first++; 61*a47a12beSStefan Roese } 62*a47a12beSStefan Roese 63*a47a12beSStefan Roese return 0; 64*a47a12beSStefan Roese } 65*a47a12beSStefan Roese 66*a47a12beSStefan Roese int ex_tab_message = 1; 67*a47a12beSStefan Roese 68*a47a12beSStefan Roese unsigned long 69*a47a12beSStefan Roese search_exception_table(unsigned long addr) 70*a47a12beSStefan Roese { 71*a47a12beSStefan Roese unsigned long ret; 72*a47a12beSStefan Roese 73*a47a12beSStefan Roese /* There is only the kernel to search. */ 74*a47a12beSStefan Roese ret = search_one_table(__start___ex_table, __stop___ex_table-1, addr); 75*a47a12beSStefan Roese /* if the serial port does not hang in exception, printf can be used */ 76*a47a12beSStefan Roese #if !defined(CONFIG_SYS_SERIAL_HANG_IN_EXCEPTION) 77*a47a12beSStefan Roese if (ex_tab_message) 78*a47a12beSStefan Roese debug("Bus Fault @ 0x%08lx, fixup 0x%08lx\n", addr, ret); 79*a47a12beSStefan Roese #endif 80*a47a12beSStefan Roese if (ret) return ret; 81*a47a12beSStefan Roese 82*a47a12beSStefan Roese return 0; 83*a47a12beSStefan Roese } 84