/* * linux/arch/arm/mm/alignment.c * * Copyright (C) 1995 Linus Torvalds * Modifications for ARM processor (c) 1995-2001 Russell King * Thumb alignment fault fixups (c) 2004 MontaVista Software, Inc. * - Adapted from gdb/sim/arm/thumbemu.c -- Thumb instruction emulation. * Copyright (C) 1996, Cygnus Software Technologies Ltd. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include "fault.h" /* * 32-bit misaligned trap handler (c) 1998 San Mehat (CCC) -July 1998 * /proc/sys/debug/alignment, modified and integrated into * Linux 2.1 by Russell King * * Speed optimisations and better fault handling by Russell King. * * *** NOTE *** * This code is not portable to processors with late data abort handling. */ #define CODING_BITS(i) (i & 0x0e000000) #define LDST_I_BIT(i) (i & (1 << 26)) /* Immediate constant */ #define LDST_P_BIT(i) (i & (1 << 24)) /* Preindex */ #define LDST_U_BIT(i) (i & (1 << 23)) /* Add offset */ #define LDST_W_BIT(i) (i & (1 << 21)) /* Writeback */ #define LDST_L_BIT(i) (i & (1 << 20)) /* Load */ #define LDST_P_EQ_U(i) ((((i) ^ ((i) >> 1)) & (1 << 23)) == 0) #define LDSTHD_I_BIT(i) (i & (1 << 22)) /* double/half-word immed */ #define LDM_S_BIT(i) (i & (1 << 22)) /* write CPSR from SPSR */ #define RN_BITS(i) ((i >> 16) & 15) /* Rn */ #define RD_BITS(i) ((i >> 12) & 15) /* Rd */ #define RM_BITS(i) (i & 15) /* Rm */ #define REGMASK_BITS(i) (i & 0xffff) #define OFFSET_BITS(i) (i & 0x0fff) #define IS_SHIFT(i) (i & 0x0ff0) #define SHIFT_BITS(i) ((i >> 7) & 0x1f) #define SHIFT_TYPE(i) (i & 0x60) #define SHIFT_LSL 0x00 #define SHIFT_LSR 0x20