From 34c2f668d0f6b2ca1c076d8170d6cd4f2235a9d4 Mon Sep 17 00:00:00 2001 From: Leonid Yegoshin Date: Mon, 25 Mar 2013 13:18:07 -0500 Subject: MIPS: microMIPS: Add unaligned access support. Add logic needed to handle unaligned accesses in microMIPS mode. Signed-off-by: Steven J. Hill Signed-off-by: Leonid Yegoshin --- arch/mips/kernel/process.c | 101 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 101 insertions(+) (limited to 'arch/mips/kernel/process.c') diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index 3be4405..ef53376 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -7,6 +7,7 @@ * Copyright (C) 2005, 2006 by Ralf Baechle (ralf@linux-mips.org) * Copyright (C) 1999, 2000 Silicon Graphics, Inc. * Copyright (C) 2004 Thiemo Seufer + * Copyright (C) 2013 Imagination Technologies Ltd. */ #include #include @@ -243,34 +244,115 @@ struct mips_frame_info { static inline int is_ra_save_ins(union mips_instruction *ip) { +#ifdef CONFIG_CPU_MICROMIPS + union mips_instruction mmi; + + /* + * swsp ra,offset + * swm16 reglist,offset(sp) + * swm32 reglist,offset(sp) + * sw32 ra,offset(sp) + * jradiussp - NOT SUPPORTED + * + * microMIPS is way more fun... + */ + if (mm_insn_16bit(ip->halfword[0])) { + mmi.word = (ip->halfword[0] << 16); + return ((mmi.mm16_r5_format.opcode == mm_swsp16_op && + mmi.mm16_r5_format.rt == 31) || + (mmi.mm16_m_format.opcode == mm_pool16c_op && + mmi.mm16_m_format.func == mm_swm16_op)); + } + else { + mmi.halfword[0] = ip->halfword[1]; + mmi.halfword[1] = ip->halfword[0]; + return ((mmi.mm_m_format.opcode == mm_pool32b_op && + mmi.mm_m_format.rd > 9 && + mmi.mm_m_format.base == 29 && + mmi.mm_m_format.func == mm_swm32_func) || + (mmi.i_format.opcode == mm_sw32_op && + mmi.i_format.rs == 29 && + mmi.i_format.rt == 31)); + } +#else /* sw / sd $ra, offset($sp) */ return (ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) && ip->i_format.rs == 29 && ip->i_format.rt == 31; +#endif } static inline int is_jal_jalr_jr_ins(union mips_instruction *ip) { +#ifdef CONFIG_CPU_MICROMIPS + /* + * jr16,jrc,jalr16,jalr16 + * jal + * jalr/jr,jalr.hb/jr.hb,jalrs,jalrs.hb + * jraddiusp - NOT SUPPORTED + * + * microMIPS is kind of more fun... + */ + union mips_instruction mmi; + + mmi.word = (ip->halfword[0] << 16); + + if ((mmi.mm16_r5_format.opcode == mm_pool16c_op && + (mmi.mm16_r5_format.rt & mm_jr16_op) == mm_jr16_op) || + ip->j_format.opcode == mm_jal32_op) + return 1; + if (ip->r_format.opcode != mm_pool32a_op || + ip->r_format.func != mm_pool32axf_op) + return 0; + return (((ip->u_format.uimmediate >> 6) & mm_jalr_op) == mm_jalr_op); +#else if (ip->j_format.opcode == jal_op) return 1; if (ip->r_format.opcode != spec_op) return 0; return ip->r_format.func == jalr_op || ip->r_format.func == jr_op; +#endif } static inline int is_sp_move_ins(union mips_instruction *ip) { +#ifdef CONFIG_CPU_MICROMIPS + /* + * addiusp -imm + * addius5 sp,-imm + * addiu32 sp,sp,-imm + * jradiussp - NOT SUPPORTED + * + * microMIPS is not more fun... + */ + if (mm_insn_16bit(ip->halfword[0])) { + union mips_instruction mmi; + + mmi.word = (ip->halfword[0] << 16); + return ((mmi.mm16_r3_format.opcode == mm_pool16d_op && + mmi.mm16_r3_format.simmediate && mm_addiusp_func) || + (mmi.mm16_r5_format.opcode == mm_pool16d_op && + mmi.mm16_r5_format.rt == 29)); + } + return (ip->mm_i_format.opcode == mm_addiu32_op && + ip->mm_i_format.rt == 29 && ip->mm_i_format.rs == 29); +#else /* addiu/daddiu sp,sp,-imm */ if (ip->i_format.rs != 29 || ip->i_format.rt != 29) return 0; if (ip->i_format.opcode == addiu_op || ip->i_format.opcode == daddiu_op) return 1; +#endif return 0; } static int get_frame_info(struct mips_frame_info *info) { +#ifdef CONFIG_CPU_MICROMIPS + union mips_instruction *ip = (void *) (((char *) info->func) - 1); +#else union mips_instruction *ip = info->func; +#endif unsigned max_insns = info->func_size / sizeof(union mips_instruction); unsigned i; @@ -290,7 +372,26 @@ static int get_frame_info(struct mips_frame_info *info) break; if (!info->frame_size) { if (is_sp_move_ins(ip)) + { +#ifdef CONFIG_CPU_MICROMIPS + if (mm_insn_16bit(ip->halfword[0])) + { + unsigned short tmp; + + if (ip->halfword[0] & mm_addiusp_func) + { + tmp = (((ip->halfword[0] >> 1) & 0x1ff) << 2); + info->frame_size = -(signed short)(tmp | ((tmp & 0x100) ? 0xfe00 : 0)); + } else { + tmp = (ip->halfword[0] >> 1); + info->frame_size = -(signed short)(tmp & 0xf); + } + ip = (void *) &ip->halfword[1]; + ip--; + } else +#endif info->frame_size = - ip->i_format.simmediate; + } continue; } if (info->pc_offset == -1 && is_ra_save_ins(ip)) { -- cgit v1.1