From patchwork Wed Sep 13 16:38:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Morse X-Patchwork-Id: 13383518 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 CB4A2EE01E3 for ; Wed, 13 Sep 2023 16:40:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: 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=tlVPu81OAF9MVxEglnII+89tG2YF0j7TitXswe+nObo=; b=rt2wsvLzqd1nwc ecYuIi5sKpXLYggYUFsunWblANyjaYcNr4WOw5vkWU8yf7NcDRN+wT8SDSmvw9jD/yyt39xm8w1Uh E8/+FBhjI2Bns1c7vY5n2TnrzgtkSjNRqcKuC4mOXmj8yyTH93g/l1Ebn2BBHTQJNHyRq0Q12SPPY U73uVPF2BnB+mbZEhrZVomgTsEUX4fHyrGKgLHy1Sm4GUJBBaP7xIrLCLADqzmZmR+T6DAj00vesl MdPCmt/DUgupm7C3B5VY8z4kbv//r7vcog1dkJesAX2iNg3ECrGXJCgf1YrJpGDAVV8aEa0M8a/yI CrAKNvtNo7GWU7BTOKlQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qgSus-006MOy-1m; Wed, 13 Sep 2023 16:40:38 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qgSth-006LEp-36; Wed, 13 Sep 2023 16:39:28 +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 35227FEC; Wed, 13 Sep 2023 09:40:02 -0700 (PDT) Received: from merodach.members.linode.com (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3A6373F5A1; Wed, 13 Sep 2023 09:39:23 -0700 (PDT) From: James Morse To: linux-pm@vger.kernel.org, loongarch@lists.linux.dev, linux-acpi@vger.kernel.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org, kvmarm@lists.linux.dev Cc: x86@kernel.org, Salil Mehta , Russell King , Jean-Philippe Brucker , jianyong.wu@arm.com, justin.he@arm.com Subject: [RFC PATCH v2 16/35] ACPI: processor: Register CPUs that are online, but not described in the DSDT Date: Wed, 13 Sep 2023 16:38:04 +0000 Message-Id: <20230913163823.7880-17-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20230913163823.7880-1-james.morse@arm.com> References: <20230913163823.7880-1-james.morse@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230913_093926_091500_F278D3DB X-CRM114-Status: GOOD ( 13.06 ) 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 ACPI has two descriptions of CPUs, one in the MADT/APIC table, the other in the DSDT. Both are required. (ACPI 6.5's 8.4 "Declaring Processors" says "Each processor in the system must be declared in the ACPI namespace"). Having two descriptions allows firmware authors to get this wrong. If CPUs are described in the MADT/APIC, they will be brought online early during boot. Once the register_cpu() calls are moved to ACPI, they will be based on the DSDT description of the CPUs. When CPUs are missing from the DSDT description, they will end up online, but not registered. Add a helper that runs after acpi_init() has completed to register CPUs that are online, but weren't found in the DSDT. Any CPU that is registered by this code triggers a firmware-bug warning and kernel taint. Qemu TCG only describes the first CPU in the DSDT, unless cpu-hotplug is configured. Signed-off-by: James Morse Reviewed-by: Jonathan Cameron Reviewed-by: Gavin Shan --- drivers/acpi/acpi_processor.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index b4bde78121bb..a01e315aa16a 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -790,6 +790,25 @@ void __init acpi_processor_init(void) acpi_pcc_cpufreq_init(); } +static int __init acpi_processor_register_missing_cpus(void) +{ + int cpu; + + if (acpi_disabled) + return 0; + + for_each_online_cpu(cpu) { + if (!get_cpu_device(cpu)) { + pr_err_once(FW_BUG "CPU %u has no ACPI namespace description!\n", cpu); + add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK); + arch_register_cpu(cpu); + } + } + + return 0; +} +subsys_initcall_sync(acpi_processor_register_missing_cpus); + #ifdef CONFIG_ACPI_PROCESSOR_CSTATE /** * acpi_processor_claim_cst_control - Request _CST control from the platform.