From patchwork Tue Oct 24 15:17:52 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Russell King \(Oracle\)" X-Patchwork-Id: 737913 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4D53931A89; Tue, 24 Oct 2023 15:18:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="UFpyf7IB" Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [IPv6:2001:4d48:ad52:32c8:5054:ff:fe00:142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8A98126AB; Tue, 24 Oct 2023 08:18:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Date:Sender:Message-Id:Content-Type: Content-Transfer-Encoding:MIME-Version:Subject:Cc:To:From:References: In-Reply-To:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=WbkJcP8EfdoxIJZCXfcMKFVW/i0XQ0H+6U5ilPscurM=; b=UFpyf7IBgalvU1WbMK4uFsjopi n3QYxKYZyHK3GPF00+ghNLXiOFCtl6pp8wlAjZdeBBo+1hsVMpqhTFYqVSDnaXMgPqZAaLKwUQiDG 9uvr3egTxe1FOV02vpFPdUDsfkp9i6U6JHam5QzXbOYxN7X33nA9s439YqSld4/s9jCJov8XGKHL+ JNp7n/Wabc3e93CgHUO+oxPhtxw4O4WRPce1ABFGYGzKuH5/kRJqlr0K6ewJyURrQiZVlLdhSRdP7 w3C055XibslaZrjOpVNLKJDdeaJjqxnvqA4rMmD9NMA6hA95tQ/sT/XqTlIor9TKsrxuKAy4xVBXP pfpMPhIg==; Received: from e0022681537dd.dyn.armlinux.org.uk ([fd8f:7570:feb6:1:222:68ff:fe15:37dd]:36712 helo=rmk-PC.armlinux.org.uk) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1qvJAE-0004Rl-2N; Tue, 24 Oct 2023 16:17:50 +0100 Received: from rmk by rmk-PC.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1qvJAG-00AqQm-6R; Tue, 24 Oct 2023 16:17:52 +0100 In-Reply-To: References: From: Russell King (Oracle) 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, x86@kernel.org, linux-csky@vger.kernel.org, linux-doc@vger.kernel.org, linux-ia64@vger.kernel.org, linux-parisc@vger.kernel.org Cc: Salil Mehta , Jean-Philippe Brucker , jianyong.wu@arm.com, justin.he@arm.com, James Morse , "Rafael J. Wysocki" , Len Brown Subject: [PATCH 20/39] ACPI: processor: Register CPUs that are online, but not described in the DSDT Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline Message-Id: Sender: Russell King Date: Tue, 24 Oct 2023 16:17:52 +0100 From: James Morse 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 Signed-off-by: Russell King (Oracle) --- 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 6a542e0ce396..0511f2bc10bc 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -791,6 +791,25 @@ 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.