From patchwork Thu Dec 8 02:58:12 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guo Ren X-Patchwork-Id: 13067845 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3E3D7C4708D for ; Thu, 8 Dec 2022 02:59:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=tvMuov4fRRzk3bZGgbNg+Uf7gV6PdoVCCz+nOqxfVA0=; b=4DnCC24jxih9FJ 95Kgcl9LzC958TJ/i45drWkgopuoJOrcmEtbrOJEyRe5NAFaVuFQTowJjMji/xkRui9aD4B+Qwi0k nJdEPUNEZGbc/gmVoPTZDxqitR/ICjxor3xtAFWbLdqGMrwo7Zoxd5EQrSnQcFtfApVcITqp3GJiO j6sWijDmQ/MVnbCX0QBfDXmnrPqVBFY+JA/B5q9DIutheWRlkYzXO9g2Zn1j875PyPv9AXc4RLs3y aFpO+vRMHOrO9LIJDWKY7BnijECkVqTk2De48FlCzxAuE9ualdZqJn64bgN4slHbVM71ar6QHUihu a0wr55pm8zVe2mf3i3qg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1p378I-000clY-JW; Thu, 08 Dec 2022 02:59:34 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1p378F-000chp-DK for linux-riscv@lists.infradead.org; Thu, 08 Dec 2022 02:59:32 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 04A0861D4B; Thu, 8 Dec 2022 02:59:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C953EC433B5; Thu, 8 Dec 2022 02:59:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1670468370; bh=rRgx4hNzhe0jjK9q+Rvjiqoqgz/4yVh97abPr6C0y4s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jfGYxeCZcHz+CEeLuNUPorKvKFANyfkrnUHsztgFIv+ODD3Ic3uLcl6rcuaB/K5pl pdeOeA8EAoTSnzrBOhse/OKdfcLhKvgbGM8hX9IC4IfNATSrJL7thnOenc4F23JmhD mFFUIyU8rP4sdn3YVgY9xJuLUWuEGLvsphUG7tuWSEtScxF0JcOESJi7twqFf0l05B vUHQ+miEFAwt5k66tDYivwmeBqZsVXwbtPU7V1tP+XL7huFkidYCTenmaE5NrWcNNN mKARQcbG8eIjS5fBnxLG2qVRp6Jmne3cbrxQXvZaIffseEohDrPMzkcgMlM6BXro3a 1RvPCxFrhh4lg== From: guoren@kernel.org To: arnd@arndb.de, guoren@kernel.org, palmer@rivosinc.com, tglx@linutronix.de, peterz@infradead.org, luto@kernel.org, conor.dooley@microchip.com, heiko@sntech.de, jszhang@kernel.org, lazyparser@gmail.com, falcon@tinylab.org, chenhuacai@kernel.org, apatel@ventanamicro.com, atishp@atishpatra.org, palmer@dabbelt.com, paul.walmsley@sifive.com, mark.rutland@arm.com, zouyipeng@huawei.com, bigeasy@linutronix.de, David.Laight@aculab.com, chenzhongjin@huawei.com, greentime.hu@sifive.com, andy.chiu@sifive.com, ben@decadent.org.uk, bjorn@kernel.org Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org Subject: [PATCH -next V10 06/10] riscv: entry: Consolidate ret_from_kernel_thread into ret_from_fork Date: Wed, 7 Dec 2022 21:58:12 -0500 Message-Id: <20221208025816.138712-7-guoren@kernel.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20221208025816.138712-1-guoren@kernel.org> References: <20221208025816.138712-1-guoren@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221207_185931_550196_7204878D X-CRM114-Status: GOOD ( 12.06 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org From: Jisheng Zhang The ret_from_kernel_thread() behaves similarly with ret_from_fork(), the only difference is whether call the fn(arg) or not, this can be achieved by testing fn is NULL or not, I.E s0 is 0 or not. Many architectures have done the same thing, it make entry.S more clean. Signed-off-by: Jisheng Zhang Reviewed-by: Guo Ren Tested-by: Guo Ren Signed-off-by: Guo Ren --- arch/riscv/kernel/entry.S | 12 +++--------- arch/riscv/kernel/process.c | 5 ++--- 2 files changed, 5 insertions(+), 12 deletions(-) diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index 69097dfffdc9..e4a9140a5b99 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -132,7 +132,6 @@ END(handle_exception) * caller list: * - handle_exception * - ret_from_fork - * - ret_from_kernel_thread */ SYM_CODE_START_NOALIGN(ret_from_exception) REG_L s0, PT_STATUS(sp) @@ -323,20 +322,15 @@ END(handle_kernel_stack_overflow) ENTRY(ret_from_fork) call schedule_tail - move a0, sp /* pt_regs */ - la ra, ret_from_exception - tail syscall_exit_to_user_mode -ENDPROC(ret_from_fork) - -ENTRY(ret_from_kernel_thread) - call schedule_tail + beqz s0, 1f /* not from kernel thread */ /* Call fn(arg) */ move a0, s1 jalr s0 +1: move a0, sp /* pt_regs */ la ra, ret_from_exception tail syscall_exit_to_user_mode -ENDPROC(ret_from_kernel_thread) +ENDPROC(ret_from_fork) /* diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c index b0c63e8e867e..5108c76a14dd 100644 --- a/arch/riscv/kernel/process.c +++ b/arch/riscv/kernel/process.c @@ -34,7 +34,6 @@ EXPORT_SYMBOL(__stack_chk_guard); #endif extern asmlinkage void ret_from_fork(void); -extern asmlinkage void ret_from_kernel_thread(void); void arch_cpu_idle(void) { @@ -172,7 +171,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) /* Supervisor/Machine, irqs on: */ childregs->status = SR_PP | SR_PIE; - p->thread.ra = (unsigned long)ret_from_kernel_thread; p->thread.s[0] = (unsigned long)args->fn; p->thread.s[1] = (unsigned long)args->fn_arg; } else { @@ -182,8 +180,9 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) if (clone_flags & CLONE_SETTLS) childregs->tp = tls; childregs->a0 = 0; /* Return value of fork() */ - p->thread.ra = (unsigned long)ret_from_fork; + p->thread.s[0] = 0; } + p->thread.ra = (unsigned long)ret_from_fork; p->thread.sp = (unsigned long)childregs; /* kernel sp */ return 0; }