Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752276AbdHHMXK (ORCPT ); Tue, 8 Aug 2017 08:23:10 -0400 Received: from mailapp01.imgtec.com ([195.59.15.196]:52982 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752249AbdHHMXH (ORCPT ); Tue, 8 Aug 2017 08:23:07 -0400 From: Matt Redfearn To: Ralf Baechle CC: , Matt Redfearn , Marcin Nowakowski , , Ingo Molnar , Paul Burton Subject: [PATCH v3 6/6] MIPS: Refactor handling of stack pointer in get_frame_info Date: Tue, 8 Aug 2017 13:22:35 +0100 Message-ID: <1502194955-18018-7-git-send-email-matt.redfearn@imgtec.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1502194955-18018-1-git-send-email-matt.redfearn@imgtec.com> References: <1502194955-18018-1-git-send-email-matt.redfearn@imgtec.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.150.130.83] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3978 Lines: 123 Commit 34c2f668d0f6 ("MIPS: microMIPS: Add unaligned access support.") added handling of microMIPS instructions to manipulate the stack pointer. The code that was added violates code style rules with long lines caused by lots of nested conditionals. The added code interprets (inline) any known stack pointer manipulation instruction to find the stack frame size. Handling the microMIPS cases added quite a bit of complication to this function. Refactor is_sp_move_ins to perform the interpretation of the immediate as the instruction manipulating the stack pointer is found. This reduces the amount of indentation required in get_frame_info, and more closely matches the operation of is_ra_save_ins. Suggested-by: Maciej W. Rozycki Signed-off-by: Matt Redfearn --- Changes in v3: None Changes in v2: - Refactor is_sp_move_ins to interpret immediate inline. arch/mips/kernel/process.c | 61 +++++++++++++++++++++++----------------------- 1 file changed, 30 insertions(+), 31 deletions(-) diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index ba7d5f73c8b0..26e2cdcd0057 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -313,9 +313,11 @@ static inline int is_jump_ins(union mips_instruction *ip) #endif } -static inline int is_sp_move_ins(union mips_instruction *ip) +static inline int is_sp_move_ins(union mips_instruction *ip, int *frame_size) { #ifdef CONFIG_CPU_MICROMIPS + unsigned short tmp; + /* * addiusp -imm * addius5 sp,-imm @@ -325,20 +327,39 @@ static inline int is_sp_move_ins(union mips_instruction *ip) * microMIPS is not more fun... */ if (mm_insn_16bit(ip->word >> 16)) { - return (ip->mm16_r3_format.opcode == mm_pool16d_op && - ip->mm16_r3_format.simmediate & mm_addiusp_func) || - (ip->mm16_r5_format.opcode == mm_pool16d_op && - ip->mm16_r5_format.rt == 29); + if (ip->mm16_r3_format.opcode == mm_pool16d_op && + ip->mm16_r3_format.simmediate & mm_addiusp_func) { + tmp = ip->mm_b0_format.simmediate >> 1; + tmp = ((tmp & 0x1ff) ^ 0x100) - 0x100; + if ((tmp + 2) < 4) /* 0x0,0x1,0x1fe,0x1ff are special */ + tmp ^= 0x100; + *frame_size = -(signed short)(tmp << 2); + return 1; + } + if (ip->mm16_r5_format.opcode == mm_pool16d_op && + ip->mm16_r5_format.rt == 29) { + tmp = ip->mm16_r5_format.imm >> 1; + *frame_size = -(signed short)(tmp & 0xf); + return 1; + } + return 0; } - return ip->mm_i_format.opcode == mm_addiu32_op && - ip->mm_i_format.rt == 29 && ip->mm_i_format.rs == 29; + if (ip->mm_i_format.opcode == mm_addiu32_op && + ip->mm_i_format.rt == 29 && ip->mm_i_format.rs == 29) { + *frame_size = -ip->i_format.simmediate; + return 1; + } #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) + + if (ip->i_format.opcode == addiu_op || + ip->i_format.opcode == daddiu_op) { + *frame_size = -ip->i_format.simmediate; return 1; + } #endif return 0; } @@ -377,29 +398,7 @@ static int get_frame_info(struct mips_frame_info *info) break; if (!info->frame_size) { - if (is_sp_move_ins(&insn)) - { -#ifdef CONFIG_CPU_MICROMIPS - if (mm_insn_16bit(insn.word >> 16)) - { - unsigned short tmp; - - if (ip->mm16_r3_format.simmediate & mm_addiusp_func) - { - tmp = ip->mm_b0_format.simmediate >> 1; - tmp = ((tmp & 0x1ff) ^ 0x100) - 0x100; - /* 0x0,0x1,0x1fe,0x1ff are special */ - if ((tmp + 2) < 4) - tmp ^= 0x100; - info->frame_size = -(signed short)(tmp << 2); - } else { - tmp = (ip->mm16_r5_format.imm >> 1); - info->frame_size = -(signed short)(tmp & 0xf); - } - } else -#endif - info->frame_size = - ip->i_format.simmediate; - } + is_sp_move_ins(&insn, &info->frame_size); continue; } if (info->pc_offset == -1 && -- 2.7.4