From patchwork Mon Oct 28 10:51:49 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pierre Gondois X-Patchwork-Id: 13853282 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 85456D13570 for ; Mon, 28 Oct 2024 10:56:37 +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-Transfer-Encoding: MIME-Version:Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=y78a7K1MzjAQDxd2KKQetl6hiq708QDKPsOuaPB4jJE=; b=zxbndft1LcDgjHrlxXj5A/pzbr BMKytP2/NzEUhpTq9fkYtMtaYySiUcQJrRyShJFPuH/nNQgWrA39gKWBE3xWS+IwezIqEp0Y6hKKA YFw7WDewiQ+tfBTHRignev/FCxBoceMBLnVzOofGvhjGAYNkfba/tyyolZlk2EVT2ahzUpbP+D7UR t7CUbXPNUhUGOfhrdGMNCtYyHf75yYivzVKiglkq6Vfqs2GXKzz/h87qHeew5Yh6TFXz6yjhc27go 9TtTt3v4JBODNbQb/WHbrF18kmwZ1CmYuh9xE+orGX2FRSBd2Vj9Cc8VAtnWOlDxVTX+LE2aap8bK N461W69g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1t5NQ8-0000000AU9h-3oPl; Mon, 28 Oct 2024 10:56:24 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1t5NMZ-0000000ATEz-1UVf; Mon, 28 Oct 2024 10:53:14 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 87500497; Mon, 28 Oct 2024 03:53:09 -0700 (PDT) Received: from e126645.nice.arm.com (e126645.nice.Arm.com [10.34.111.162]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 2C7E73F73B; Mon, 28 Oct 2024 03:52:35 -0700 (PDT) From: Pierre Gondois To: linux-kernel@vger.kernel.org Cc: Dietmar Eggemann , Pierre Gondois , Catalin Marinas , Will Deacon , Paul Walmsley , Palmer Dabbelt , Albert Ou , "Rafael J. Wysocki" , Len Brown , Sudeep Holla , Greg Kroah-Hartman , Sebastian Andrzej Siewior , Clark Williams , Steven Rostedt , Jeremy Linton , Yunhui Cui , Conor Dooley , Steffen Persvold , Andrew Morton , Mathieu Desnoyers , "Borislav Petkov (AMD)" , Reinette Chatre , Tony Luck , Yury Norov , =?utf-8?b?Q2zDqW1lbnQgTMOpZ2Vy?= , linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org, linux-acpi@vger.kernel.org, linux-rt-devel@lists.linux.dev Subject: [PATCH] ACPI: CPPC: Make rmw_lock a raw_spin_lock Date: Mon, 28 Oct 2024 11:51:49 +0100 Message-Id: <20241028105200.1205509-1-pierre.gondois@arm.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241028_035243_515421_EC50A0A5 X-CRM114-Status: UNSURE ( 9.53 ) X-CRM114-Notice: Please train this message. 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 following BUG was triggered. sugov_update_shared() locks a raw_spinlock while cpc_write() locks a spinlock. To have a correct wait-type order, update rmw_lock to a raw_spinlock. Also save irq state. ============================= [ BUG: Invalid wait context ] 6.12.0-rc2-XXX #406 Not tainted ----------------------------- kworker/1:1/62 is trying to lock: ffffff8801593030 (&cpc_ptr->rmw_lock){+.+.}-{3:3}, at: cpc_write+0xcc/0x370 other info that might help us debug this: context-{5:5} 2 locks held by kworker/1:1/62: #0: ffffff897ef5ec98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2c/0x50 #1: ffffff880154e238 (&sg_policy->update_lock){....}-{2:2}, at: sugov_update_shared+0x3c/0x280 stack backtrace: CPU: 1 UID: 0 PID: 62 Comm: kworker/1:1 Not tainted 6.12.0-rc2-g9654bd3e8806 #406 Workqueue: 0x0 (events) Call trace: dump_backtrace+0xa4/0x130 show_stack+0x20/0x38 dump_stack_lvl+0x90/0xd0 dump_stack+0x18/0x28 __lock_acquire+0x480/0x1ad8 lock_acquire+0x114/0x310 _raw_spin_lock+0x50/0x70 cpc_write+0xcc/0x370 cppc_set_perf+0xa0/0x3a8 cppc_cpufreq_fast_switch+0x40/0xc0 cpufreq_driver_fast_switch+0x4c/0x218 sugov_update_shared+0x234/0x280 update_load_avg+0x6ec/0x7b8 dequeue_entities+0x108/0x830 dequeue_task_fair+0x58/0x408 __schedule+0x4f0/0x1070 schedule+0x54/0x130 worker_thread+0xc0/0x2e8 kthread+0x130/0x148 ret_from_fork+0x10/0x20 Fixes: 60949b7b8054 ("ACPI: CPPC: Fix MASK_VAL() usage") Signed-off-by: Pierre Gondois --- drivers/acpi/cppc_acpi.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index 1a40f0514eaa..e7e4bf932e28 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -1127,7 +1127,7 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val) return -ENODEV; } - raw_spin_lock_irqsave(&cpc_desc->rmw_lock, flags); + raw_spin_lock(&cpc_desc->rmw_lock); switch (size) { case 8: prev_val = readb_relaxed(vaddr); @@ -1142,7 +1142,7 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val) prev_val = readq_relaxed(vaddr); break; default: - raw_spin_unlock_irqrestore(&cpc_desc->rmw_lock, flags); + raw_spin_unlock(&cpc_desc->rmw_lock); return -EFAULT; } val = MASK_VAL_WRITE(reg, prev_val, val); @@ -1175,7 +1175,7 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val) } if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) - raw_spin_unlock_irqrestore(&cpc_desc->rmw_lock, flags); + raw_spin_unlock(&cpc_desc->rmw_lock); return ret_val; }