From patchwork Wed Sep 13 16:38:10 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Morse X-Patchwork-Id: 13383524 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 12316EE01E0 for ; Wed, 13 Sep 2023 16:41:14 +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=xY4gvLspFJLOF3fMfoAP5sQt26Nv9kzIb7mSgjP2BQM=; b=H9n9M1LcAoYpv5 3shD7lLWAqqFjzEOzV2rTH2IQBuNFyVkBbVlJMDwfPpNeaDd9M3kSGIAdR4Yo5/1GH0OIlogZPe2k tslyqPv6GlNXXXmtkp+spEAKR4fnyZEZqtCy12xpz31fNAXW2dyWXzZ4RkF25Vy2swOIz6kOHK4MV DBZRHUeeXJJ/5PVIfDRr89otf0eL84jivFRE+8ZOj1xF63FR3K7ftv/Pz3BTawpq9O4B8aRqflVFK gOlMjkRc5OAbR8fcb4UkMEhclcLwPgYxlLHYhTwxxbh4RTFfq7Sk/VqFu/n+GRO3x0KGTFDfU0x7t RkPa6/iSOTptrkneMVYA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qgSvN-006MwK-28; Wed, 13 Sep 2023 16:41:09 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qgStt-006LEp-1n; Wed, 13 Sep 2023 16:39:39 +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 5B6AA1FB; Wed, 13 Sep 2023 09:40:14 -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 60F763F5A1; Wed, 13 Sep 2023 09:39:35 -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 22/35] ACPI: Check _STA present bit before making CPUs not present Date: Wed, 13 Sep 2023 16:38:10 +0000 Message-Id: <20230913163823.7880-23-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_093937_718332_5E0A1297 X-CRM114-Status: GOOD ( 15.85 ) 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 When called acpi_processor_post_eject() unconditionally make a CPU not-present and unregisters it. To add support for AML events where the CPU has become disabled, but remains present, the _STA method should be checked before calling acpi_processor_remove(). Rename acpi_processor_post_eject() acpi_processor_remove_possible(), and check the _STA before calling. Adding the function prototype for arch_unregister_cpu() allows the preprocessor guards to be removed. After this change CPUs will remain registered and visible to user-space as offline if buggy firmware triggers an eject-request, but doesn't clear the corresponding _STA bits after _EJ0 has been called. Signed-off-by: James Morse Reviewed-by: Jonathan Cameron --- drivers/acpi/acpi_processor.c | 31 +++++++++++++++++++++++++------ include/linux/cpu.h | 1 + 2 files changed, 26 insertions(+), 6 deletions(-) diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 00dcc23d49a8..2cafea1edc24 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -457,13 +457,12 @@ static int acpi_processor_add(struct acpi_device *device, return result; } -#ifdef CONFIG_ACPI_HOTPLUG_PRESENT_CPU /* Removal */ -static void acpi_processor_post_eject(struct acpi_device *device) +static void acpi_processor_make_not_present(struct acpi_device *device) { struct acpi_processor *pr; - if (!device || !acpi_driver_data(device)) + if (!IS_ENABLED(CONFIG_ACPI_HOTPLUG_PRESENT_CPU)) return; pr = acpi_driver_data(device); @@ -501,7 +500,29 @@ static void acpi_processor_post_eject(struct acpi_device *device) free_cpumask_var(pr->throttling.shared_cpu_map); kfree(pr); } -#endif /* CONFIG_ACPI_HOTPLUG_PRESENT_CPU */ + +static void acpi_processor_post_eject(struct acpi_device *device) +{ + struct acpi_processor *pr; + unsigned long long sta; + acpi_status status; + + if (!device) + return; + + pr = acpi_driver_data(device); + if (!pr || pr->id >= nr_cpu_ids || invalid_phys_cpuid(pr->phys_id)) + return; + + status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta); + if (ACPI_FAILURE(status)) + return; + + if (cpu_present(pr->id) && !(sta & ACPI_STA_DEVICE_PRESENT)) { + acpi_processor_make_not_present(device); + return; + } +} #ifdef CONFIG_ARCH_MIGHT_HAVE_ACPI_PDC bool __init processor_physically_present(acpi_handle handle) @@ -626,9 +647,7 @@ static const struct acpi_device_id processor_device_ids[] = { static struct acpi_scan_handler processor_handler = { .ids = processor_device_ids, .attach = acpi_processor_add, -#ifdef CONFIG_ACPI_HOTPLUG_PRESENT_CPU .post_eject = acpi_processor_post_eject, -#endif .hotplug = { .enabled = true, }, diff --git a/include/linux/cpu.h b/include/linux/cpu.h index a71691d7c2ca..e117c06e0c6b 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -81,6 +81,7 @@ struct device *cpu_device_create(struct device *parent, void *drvdata, const struct attribute_group **groups, const char *fmt, ...); extern int arch_register_cpu(int cpu); +extern void arch_unregister_cpu(int cpu); #ifdef CONFIG_HOTPLUG_CPU extern void unregister_cpu(struct cpu *cpu); extern ssize_t arch_cpu_probe(const char *, size_t);