From patchwork Wed Dec 13 12:49:26 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: 13490860 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="ksm1NKE0" 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 BBD94A4; Wed, 13 Dec 2023 04:49:29 -0800 (PST) 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=TBP+R/WnvXUfMyTGAeqg+zDZHJCc+YgTDDU9BjPnE9g=; b=ksm1NKE0scGCsyGD98yGeYXubr hB68rislLCulb5Vrhre3UZbE0fxzcZ56LCzd5+Jx/UWiG25ops81IW195eVeI8hCQ5EANLwLRWDLA BmC4J9EmHzrINYzT6DlHEOYKjkDSM0BA4JczIJo4NcTNxODYtV4qUZxAeg1J7TH+VUw4KpKxTHLPz mpmzh+ajIEmyMMSsM4T56yj66lxMZNRqG8qaewbcE/l7g7lRVI3rtAua0Mp747FPjrkKFWvOHFqFD 2bv0xOQ5zwDWdKfZo9UeZUjaRSQLgY0cl+j0aJ56oPkOTkQW4csde5cwMAKUOpa9x8rBSwoAiid2c Df8GEnuA==; Received: from e0022681537dd.dyn.armlinux.org.uk ([fd8f:7570:feb6:1:222:68ff:fe15:37dd]:43366 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 1rDOg0-0008D5-24; Wed, 13 Dec 2023 12:49:24 +0000 Received: from rmk by rmk-PC.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1rDOg2-00Dvjk-RI; Wed, 13 Dec 2023 12:49:26 +0000 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, acpica-devel@lists.linuxfoundation.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 Subject: [PATCH RFC v3 03/21] ACPI: processor: Register CPUs that are online, but not described in the DSDT Precedence: bulk X-Mailing-List: linux-parisc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline Message-Id: Sender: Russell King Date: Wed, 13 Dec 2023 12:49:26 +0000 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 Tested-by: Miguel Luis Tested-by: Vishnu Pajjuri Tested-by: Jianyong Wu 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.