From nobody Sun Apr 26 08:22:31 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A8855C43334 for ; Wed, 15 Jun 2022 10:30:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347790AbiFOKa0 (ORCPT ); Wed, 15 Jun 2022 06:30:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49622 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347675AbiFOK3j (ORCPT ); Wed, 15 Jun 2022 06:29:39 -0400 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 3FE4D4B87F for ; Wed, 15 Jun 2022 03:29:37 -0700 (PDT) Received: from linux.localdomain (unknown [113.200.148.30]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9Dxr9+NtKliy5VDAA--.20939S3; Wed, 15 Jun 2022 18:29:35 +0800 (CST) From: Tiezhu Yang To: Huacai Chen , WANG Xuerui Cc: Xuefeng Li , Jianmin Lv , Jun Yi , Rui Wang , linux-kernel@vger.kernel.org Subject: [RFC PATCH v3 1/3] LoongArch: Add TI_SYSCALL in output_thread_info_defines() Date: Wed, 15 Jun 2022 18:29:31 +0800 Message-Id: <1655288973-6066-2-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1655288973-6066-1-git-send-email-yangtiezhu@loongson.cn> References: <1655288973-6066-1-git-send-email-yangtiezhu@loongson.cn> X-CM-TRANSID: AQAAf9Dxr9+NtKliy5VDAA--.20939S3 X-Coremail-Antispam: 1UD129KBjvdXoW7Wr48Ww17Wr4fKr43tr4fKrg_yoWkWwc_Xr nrGwn8GFW8JrWIq3Wqyw4fXr4jya4vkFyrXFZ7CrWxt3WDtry5Jr4rZ348CrykKrWkGrs8 C3ykW3Wkur1jkjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbSkFF20E14v26r4j6ryUM7CY07I20VC2zVCF04k26cxKx2IYs7xG 6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUGwA2048vs2IY02 0Ec7CjxVAFwI0_JFI_Gr1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xv wVC0I7IYx2IY67AKxVW5JVW7JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVWxJVW8Jr1l84 ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_GcCE3s1le2I2 62IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcV AFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r4j6F4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG 0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1lc2xSY4AK67AK6r4DMxAIw28Icx kI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2Iq xVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUAVWUtwCIc40Y0x0EwIxGrwCI42 IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY 6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Gr0_Cr1lIxAIcVC2z280aV CY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7VUjq-eDUUUUU== X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" The initial idea was to store the syscall number in PT_R11, and then we can get the syscall number from PT_R11 to check before SAVE and RESTORE in handle_syscall, but PT_R11 may be overwritten by the signal handler and the syscall number is lost. Add TI_SYSCALL in output_thread_info_defines(), then we can store the syscall number in TI_SYSCALL. This is preparation for later patch. Signed-off-by: Tiezhu Yang --- arch/loongarch/kernel/asm-offsets.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/loongarch/kernel/asm-offsets.c b/arch/loongarch/kernel/as= m-offsets.c index bfb65eb..4757ebe 100644 --- a/arch/loongarch/kernel/asm-offsets.c +++ b/arch/loongarch/kernel/asm-offsets.c @@ -81,6 +81,7 @@ void output_thread_info_defines(void) OFFSET(TI_CPU, thread_info, cpu); OFFSET(TI_PRE_COUNT, thread_info, preempt_count); OFFSET(TI_REGS, thread_info, regs); + OFFSET(TI_SYSCALL, thread_info, syscall); DEFINE(_THREAD_SIZE, THREAD_SIZE); DEFINE(_THREAD_MASK, THREAD_MASK); DEFINE(_IRQ_STACK_SIZE, IRQ_STACK_SIZE); --=20 2.1.0 From nobody Sun Apr 26 08:22:31 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 30CB7C43334 for ; Wed, 15 Jun 2022 10:30:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347060AbiFOKab (ORCPT ); Wed, 15 Jun 2022 06:30:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49608 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347743AbiFOK3j (ORCPT ); Wed, 15 Jun 2022 06:29:39 -0400 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id C93454B1D0 for ; Wed, 15 Jun 2022 03:29:37 -0700 (PDT) Received: from linux.localdomain (unknown [113.200.148.30]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9Dxr9+NtKliy5VDAA--.20939S4; Wed, 15 Jun 2022 18:29:36 +0800 (CST) From: Tiezhu Yang To: Huacai Chen , WANG Xuerui Cc: Xuefeng Li , Jianmin Lv , Jun Yi , Rui Wang , linux-kernel@vger.kernel.org Subject: [RFC PATCH v3 2/3] LoongArch: Only clone and clone3 need to call SAVE_STATIC Date: Wed, 15 Jun 2022 18:29:32 +0800 Message-Id: <1655288973-6066-3-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1655288973-6066-1-git-send-email-yangtiezhu@loongson.cn> References: <1655288973-6066-1-git-send-email-yangtiezhu@loongson.cn> X-CM-TRANSID: AQAAf9Dxr9+NtKliy5VDAA--.20939S4 X-Coremail-Antispam: 1UD129KBjvdXoWrZr1ktw17tr1kWr4UGryrCrg_yoWkJwc_A3 ZrG3yUW3yrAa9aqF9rXr4rX3ZFkw48KF1vkrs2grWYka45t39rtwsa9w1UAF4DKrn3Wrs5 ZrWUXFyvkr1akjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbSkFF20E14v26ryj6rWUM7CY07I20VC2zVCF04k26cxKx2IYs7xG 6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUXwA2048vs2IY02 0Ec7CjxVAFwI0_Gr0_Xr1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xv wVC0I7IYx2IY67AKxVW5JVW7JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVWxJVW8Jr1l84 ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_GcCE3s1le2I2 62IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcV AFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r4j6F4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG 0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1lc2xSY4AK67AK6r4DMxAIw28Icx kI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2Iq xVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUAVWUtwCIc40Y0x0EwIxGrwCI42 IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY 6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Gr0_Cr1lIxAIcVC2z280aV CY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7VUUItCDUUUUU== X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" In handle_syscall, it is unnecessary to call SAVE_STATIC for all syscalls, only clone and clone3 need to do this operation, so it is better to check the syscall number before call SAVE_STATIC. With this patch, it can reduce many store instructions. Signed-off-by: Tiezhu Yang --- arch/loongarch/kernel/entry.S | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/loongarch/kernel/entry.S b/arch/loongarch/kernel/entry.S index d5b3dbc..a0f7fcc 100644 --- a/arch/loongarch/kernel/entry.S +++ b/arch/loongarch/kernel/entry.S @@ -14,6 +14,7 @@ #include #include #include +#include =20 .text .cfi_sections .debug_frame @@ -56,8 +57,17 @@ SYM_FUNC_START(handle_syscall) cfi_st u0, PT_R21 cfi_st fp, PT_R22 =20 + /* Syscall number held in a7, only clone and clone3 need to call SAVE_STA= TIC. */ + li.w t3, __NR_clone + beq a7, t3, 1f + li.w t3, __NR_clone3 + beq a7, t3, 1f + b 2f + +1: SAVE_STATIC =20 +2: move u0, t0 li.d tp, ~_THREAD_MASK and tp, tp, sp --=20 2.1.0 From nobody Sun Apr 26 08:22:31 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 14379C43334 for ; Wed, 15 Jun 2022 10:30:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343876AbiFOKaS (ORCPT ); Wed, 15 Jun 2022 06:30:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49596 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347673AbiFOK3j (ORCPT ); Wed, 15 Jun 2022 06:29:39 -0400 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 068674162A for ; Wed, 15 Jun 2022 03:29:37 -0700 (PDT) Received: from linux.localdomain (unknown [113.200.148.30]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9Dxr9+NtKliy5VDAA--.20939S5; Wed, 15 Jun 2022 18:29:36 +0800 (CST) From: Tiezhu Yang To: Huacai Chen , WANG Xuerui Cc: Xuefeng Li , Jianmin Lv , Jun Yi , Rui Wang , linux-kernel@vger.kernel.org Subject: [RFC PATCH v3 3/3] LoongArch: No need to call RESTORE_ALL_AND_RET for all syscalls Date: Wed, 15 Jun 2022 18:29:33 +0800 Message-Id: <1655288973-6066-4-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1655288973-6066-1-git-send-email-yangtiezhu@loongson.cn> References: <1655288973-6066-1-git-send-email-yangtiezhu@loongson.cn> X-CM-TRANSID: AQAAf9Dxr9+NtKliy5VDAA--.20939S5 X-Coremail-Antispam: 1UD129KBjvJXoW7uw4UAF4UCr4kZFyfZw13Arb_yoW8KFWxpw nFvFnYkF4jgF97Ary3XrWxurWay3Z7GF4UuFsFkrZ5uw1vqr98Xryvya4Dtr12yw48trW8 Wa4rGwsIgFyqq3JanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBa14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JrWl82xGYIkIc2 x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_Xr0_Ar1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Cr0_Gr1UM2 8EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s0DM2AI xVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20x vE14v26r1j6r18McIj6I8E87Iv67AKxVW8JVWxJwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xv r2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7MxkIecxEwVAFwVW8twCF04k20x vY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I 3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIxkGc2Ij64vIr41lIx AIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAI cVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r4j6F4UMIIF0xvEx4A2js IEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x0JUDDGOUUUUU= X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" In handle_syscall, it is unnecessary to call RESTORE_ALL_AND_RET for all syscalls. (1) clone and clone3 call RESTORE_STATIC_SOME_SP_AND_RET. (2) rt_sigreturn and rt_sigsuspend call RESTORE_TEMP_SOME_SP_AND_RET. (3) The other syscalls call RESTORE_SOME_SP_AND_RET. With this patch, it can reduce many load instructions. Signed-off-by: Tiezhu Yang --- arch/loongarch/include/asm/stackframe.h | 17 +++++++++++++++++ arch/loongarch/kernel/entry.S | 25 ++++++++++++++++++++++++- 2 files changed, 41 insertions(+), 1 deletion(-) diff --git a/arch/loongarch/include/asm/stackframe.h b/arch/loongarch/inclu= de/asm/stackframe.h index 4ca9530..52649a5f 100644 --- a/arch/loongarch/include/asm/stackframe.h +++ b/arch/loongarch/include/asm/stackframe.h @@ -216,4 +216,21 @@ RESTORE_SP_AND_RET \docfi .endm =20 + .macro RESTORE_SOME_SP_AND_RET docfi=3D0 + RESTORE_SOME \docfi + RESTORE_SP_AND_RET \docfi + .endm + + .macro RESTORE_STATIC_SOME_SP_AND_RET docfi=3D0 + RESTORE_STATIC \docfi + RESTORE_SOME \docfi + RESTORE_SP_AND_RET \docfi + .endm + + .macro RESTORE_TEMP_SOME_SP_AND_RET docfi=3D0 + RESTORE_TEMP \docfi + RESTORE_SOME \docfi + RESTORE_SP_AND_RET \docfi + .endm + #endif /* _ASM_STACKFRAME_H */ diff --git a/arch/loongarch/kernel/entry.S b/arch/loongarch/kernel/entry.S index a0f7fcc..e27e38b 100644 --- a/arch/loongarch/kernel/entry.S +++ b/arch/loongarch/kernel/entry.S @@ -72,10 +72,33 @@ SYM_FUNC_START(handle_syscall) li.d tp, ~_THREAD_MASK and tp, tp, sp =20 + /* Syscall number held in a7, we can store it in TI_SYSCALL. */ + LONG_S a7, tp, TI_SYSCALL + move a0, sp bl do_syscall =20 - RESTORE_ALL_AND_RET + /* + * Syscall number held in a7 which is stored in TI_SYSCALL. + * clone and clone3 call RESTORE_STATIC_SOME_SP_AND_RET. + * rt_sigreturn and rt_sigsuspend call RESTORE_TEMP_SOME_SP_AND_RET. + * The other syscalls call RESTORE_SOME_SP_AND_RET. + */ + LONG_L t3, tp, TI_SYSCALL + li.w t4, __NR_clone + beq t3, t4, 3f + li.w t4, __NR_clone3 + beq t3, t4, 3f + li.w t4, __NR_rt_sigreturn + beq t3, t4, 4f + li.w t4, __NR_rt_sigsuspend + beq t3, t4, 4f + + RESTORE_SOME_SP_AND_RET +3: + RESTORE_STATIC_SOME_SP_AND_RET +4: + RESTORE_TEMP_SOME_SP_AND_RET SYM_FUNC_END(handle_syscall) =20 SYM_CODE_START(ret_from_fork) --=20 2.1.0