Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752489AbdCAPb4 (ORCPT ); Wed, 1 Mar 2017 10:31:56 -0500 Received: from mailapp01.imgtec.com ([195.59.15.196]:32822 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751047AbdCAPbs (ORCPT ); Wed, 1 Mar 2017 10:31:48 -0500 From: Matt Redfearn To: Ralf Baechle CC: , Matt Redfearn , Marcin Nowakowski , , "Maciej W. Rozycki" , Paul Burton Subject: [PATCH v2 3/5] MIPS: Refactor handling of stack pointer in get_frame_info Date: Wed, 1 Mar 2017 14:41:18 +0000 Message-ID: <1488379280-2954-4-git-send-email-matt.redfearn@imgtec.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1488379280-2954-1-git-send-email-matt.redfearn@imgtec.com> References: <1488379280-2954-1-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: 3801 Lines: 120 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. This commit refactors 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 v2: - Refactor is_sp_move_ins to interpret immediate inline. arch/mips/kernel/process.c | 58 ++++++++++++++++++++++------------------------ 1 file changed, 28 insertions(+), 30 deletions(-) diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index 799273d45d21..1113f1f15bc1 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -311,9 +311,11 @@ 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 @@ -323,20 +325,37 @@ static inline int is_sp_move_ins(union mips_instruction *ip) * microMIPS is not more fun... */ if (mm_insn_16bit(ip->halfword[1])) { - 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->halfword[1] >> 1) & 0x1ff; + tmp = (tmp ^ 0x100) - 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->halfword[1] >> 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; } @@ -377,28 +396,7 @@ 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(ip->halfword[0])) - { - unsigned short tmp; - - if (ip->halfword[0] & mm_addiusp_func) - { - tmp = (ip->halfword[0] >> 1) & 0x1ff; - tmp = (tmp ^ 0x100) - 0x100; - info->frame_size = -(signed short)(tmp << 2); - } 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; - } + is_sp_move_ins(&insn, &info->frame_size); continue; } if (info->pc_offset == -1 && -- 2.7.4