From patchwork Wed Dec 13 12:50:02 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: 13490867 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="rkyEttm/" 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 B9FC1F2; Wed, 13 Dec 2023 04:50:07 -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=+T8kn3k9b5NRBjWSUweuCxqkK4fxT1FVGeJHMIqvr6c=; b=rkyEttm/kwtrIQTS1tSEUUuy10 b9f4MBsDpOC7fICaT9EKK+Erd3u3912ckPVBYTTp9qSDOl75HckFt2qX6y4YCvnlnnFH14GeyAlCD Li+m9IPqogcUFaNQ7kQHxE4OpBhAZYtFI73RMlMLVN/fOwXSoM636lHWmCwWwcFfIS24kketvfMg0 EU7oxLVMKZRpauGDtcKWJQe8L2+C4eMsQ9rGXcJRTKtsWv+vOvGMNbx0tW/5qZx4LHU0G5Ov/QN7B +CzbJp4H7r/dgAdh7yyBwxBVH4y/8nMxcj74KZ3bUuRotM59px0g35yT9z1oC88KgqotI5CkI10kd HXtcF17Q==; Received: from e0022681537dd.dyn.armlinux.org.uk ([fd8f:7570:feb6:1:222:68ff:fe15:37dd]:50928 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 1rDOga-0008F6-2I; Wed, 13 Dec 2023 12:50:01 +0000 Received: from rmk by rmk-PC.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1rDOgc-00DvkW-PZ; Wed, 13 Dec 2023 12:50:02 +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 10/21] ACPI: Check _STA present bit before making CPUs not present 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 12:50:02 +0000 From: James Morse 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 Tested-by: Miguel Luis Tested-by: Vishnu Pajjuri Tested-by: Jianyong Wu Reviewed-by: Jonathan Cameron --- Changes since RFC v3: * Move IS_ENABLED(CONFIG_ACPI_HOTPLUG_PRESENT_CPU) into separate patch. Outstanding comments: https://lore.kernel.org/r/20230914153110.00003e38@Huawei.com https://lore.kernel.org/r/518859b1-64a9-d723-963c-56c7f6fc2da1@redhat.com This contains a repeat of the IS_ENABLED() issue which we don't think is a problem - but there is another issue mentioned in that comment. --- drivers/acpi/acpi_processor.c | 28 ++++++++++++++++++++++++---- 1 file changed, 24 insertions(+), 4 deletions(-) diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 01c460881662..19fceb3ec4e2 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -458,16 +458,13 @@ static int acpi_processor_add(struct acpi_device *device, } /* 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 (!IS_ENABLED(CONFIG_ACPI_HOTPLUG_PRESENT_CPU)) return; - if (!device || !acpi_driver_data(device)) - return; - pr = acpi_driver_data(device); if (pr->id >= nr_cpu_ids) goto out; @@ -504,6 +501,29 @@ static void acpi_processor_post_eject(struct acpi_device *device) kfree(pr); } +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) {