From patchwork Thu Feb 13 13:00:04 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jinjie Ruan X-Patchwork-Id: 13973233 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 4D9DBC0219D for ; Thu, 13 Feb 2025 13:07:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: Content-Transfer-Encoding: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=M5sGTGijkijKquhsZpeteo9Z+KqHf8edhKrasj8jgT8=; b=OXZTGCdYRi3P+dGcAD1/hGxEaD Xez1AvAvLKHVfNako8dlaS5DO1GLxcLBWZKXDGR/1IxQoLfT4q+dVGSGMhwUMx9WbE5zEUd6ZpRWM +KSmnh7o7ABqh0hVLDmzSxUABUEH6/MF3xDtMWh9B8fY1BZvoJo17ggwbfXdaLMCfEDLGGMkOpaLM RTE/SZOazGL1gLlV/pSGtsz6i4ReRvPLR71hVe5NcBb8+oJcnx8PLTUPfXn2mHOPShuoRDxH3gzqF tdi678McVtKOiAZecxfwoMabqS01tzY6uBoenoNaD8/G2iSSl5pgavFFP05qDTTMOkWGJJiQVlyRw 9LwaZ9MQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tiYwG-0000000B6BB-27My; Thu, 13 Feb 2025 13:07:32 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tiYqq-0000000B517-233I for linux-arm-kernel@bombadil.infradead.org; Thu, 13 Feb 2025 13:01:56 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Type:Content-Transfer-Encoding :MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:CC:To:From: Sender:Reply-To:Content-ID:Content-Description; bh=M5sGTGijkijKquhsZpeteo9Z+KqHf8edhKrasj8jgT8=; b=l62kukB+8NSl0k9XolIIYvYIVp 5kzpQQeC5whtjgf7TUEHEx47Ay3VHr9lANn034gRLFXFK4IBC50PeI8rEvqnKKXSYftjer5Gki2a7 cPnobm3Su+hrZGBiMiVdCYukKJxfEAj9TIJ2HaX0A1vsFhz4uAw9p67PQIDbqlmqi60dCTv/0YVi0 uL4wyiN32gQt4G1MmEhHhd5vMohtGPSDIU8yp1Dh42xgDX49bCRKZ8xaKilS9vcsxJdZTLP8kpKPX DE01B2OCtp529YVO6StwxE5oa8deYHXiRhG8bu8xkRCpBMBSONvlt3UbjEJ62OHT91FZJUTIICAz3 2W4DOnvQ==; Received: from szxga06-in.huawei.com ([45.249.212.32]) by desiato.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tiYqm-00000000zkq-3IFo for linux-arm-kernel@lists.infradead.org; Thu, 13 Feb 2025 13:01:55 +0000 Received: from mail.maildlp.com (unknown [172.19.163.44]) by szxga06-in.huawei.com (SkyGuard) with ESMTP id 4YtwLn4XMqz20p2K; Thu, 13 Feb 2025 21:02:09 +0800 (CST) Received: from kwepemg200008.china.huawei.com (unknown [7.202.181.35]) by mail.maildlp.com (Postfix) with ESMTPS id EBBFC1400D2; Thu, 13 Feb 2025 21:01:39 +0800 (CST) Received: from huawei.com (10.90.53.73) by kwepemg200008.china.huawei.com (7.202.181.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Thu, 13 Feb 2025 21:01:38 +0800 From: Jinjie Ruan To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , CC: Subject: [PATCH -next v6 5/8] arm64: entry: Use preempt_count() and need_resched() helper Date: Thu, 13 Feb 2025 21:00:04 +0800 Message-ID: <20250213130007.1418890-6-ruanjinjie@huawei.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250213130007.1418890-1-ruanjinjie@huawei.com> References: <20250213130007.1418890-1-ruanjinjie@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.90.53.73] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemg200008.china.huawei.com (7.202.181.35) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250213_130153_705920_93D7FE3E X-CRM114-Status: GOOD ( 13.55 ) X-BeenThere: linux-arm-kernel@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-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org The generic entry code uses preempt_count() and need_resched() helpers to check if it should do preempt_schedule_irq(). Currently, arm64 use its own check logic, that is "READ_ONCE(current_thread_info()->preempt_count == 0", which is equivalent to "preempt_count() == 0 && need_resched()". In preparation for moving arm64 over to the generic entry code, use these helpers to replace arm64's own code and move it ahead. No functional changes. Signed-off-by: Jinjie Ruan --- v6: - Update the commit message. - Move this ahead before we change the preemption logic to preempt non-IRQ exceptions. --- arch/arm64/kernel/entry-common.c | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c index 94e4132213ce..dceef4cb140b 100644 --- a/arch/arm64/kernel/entry-common.c +++ b/arch/arm64/kernel/entry-common.c @@ -294,14 +294,6 @@ static inline bool arm64_preempt_schedule_irq(void) if (!need_irq_preemption()) return false; - /* - * Note: thread_info::preempt_count includes both thread_info::count - * and thread_info::need_resched, and is not equivalent to - * preempt_count(). - */ - if (READ_ONCE(current_thread_info()->preempt_count) != 0) - return false; - /* * DAIF.DA are cleared at the start of IRQ/FIQ handling, and when GIC * priority masking is used the GIC irqchip driver will clear DAIF.IF @@ -593,8 +585,10 @@ static __always_inline void __el1_irq(struct pt_regs *regs, do_interrupt_handler(regs, handler); irq_exit_rcu(); - if (arm64_preempt_schedule_irq()) - preempt_schedule_irq(); + if (!preempt_count() && need_resched()) { + if (arm64_preempt_schedule_irq()) + preempt_schedule_irq(); + } exit_to_kernel_mode(regs, state); }