From patchwork Tue Feb 18 14:10:15 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yicong Yang X-Patchwork-Id: 13979860 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 DD154C02198 for ; Tue, 18 Feb 2025 14:12:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: Content-Transfer-Encoding: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=FGGTxpGEya+y3DCKSasDByHMsQJWfIB0xG5m7Wt2qrk=; b=Y9EjpFvZKvCf7m5cIpVEivBlF9 /n2xnAyAF5rz9sUXKHDNeUost9A0FEliyosefvvLAsvEU5dq7Q3RdfSrAGJRaFY+ElhgOR+f+BT/n lkCbz6/dZRdUAAUF6mchWUyCel9R4Gj4fEdF8HGhgKx5Klf+F/ZCV8HXv4Jj7B7k6zVkPpGADdu50 p5Kns7ZrViZNHf5ef4+yAfgjcRBpD4bKTnu61VViSlTOaKiw6oSlIywuk2pQChwRDkq7c/SC189yN rpReA+lJA4mIkyeX9uFqMOiQMoag7AF5TzlRRAm6R0jEri/QiYyZXMsBppzKMvJjlZjCqIhfqRmjf 3YB1OpZw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tkOKD-00000008S6d-2liQ; Tue, 18 Feb 2025 14:11:49 +0000 Received: from szxga05-in.huawei.com ([45.249.212.191]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tkOIi-00000008RiN-40Bh for linux-arm-kernel@lists.infradead.org; Tue, 18 Feb 2025 14:10:19 +0000 Received: from mail.maildlp.com (unknown [172.19.162.112]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4Yy1bB44KszMrc8; Tue, 18 Feb 2025 22:08:38 +0800 (CST) Received: from kwepemd200014.china.huawei.com (unknown [7.221.188.8]) by mail.maildlp.com (Postfix) with ESMTPS id 4A3491400D6; Tue, 18 Feb 2025 22:10:08 +0800 (CST) Received: from localhost.localdomain (10.50.165.33) by kwepemd200014.china.huawei.com (7.221.188.8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.34; Tue, 18 Feb 2025 22:10:07 +0800 From: Yicong Yang To: , , , , , , , , , , , CC: , , , , , , , , , , , , , Subject: [PATCH v11 1/4] cpu/SMT: Provide a default topology_is_primary_thread() Date: Tue, 18 Feb 2025 22:10:15 +0800 Message-ID: <20250218141018.18082-2-yangyicong@huawei.com> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20250218141018.18082-1-yangyicong@huawei.com> References: <20250218141018.18082-1-yangyicong@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.50.165.33] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To kwepemd200014.china.huawei.com (7.221.188.8) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250218_061017_428713_68B1A6E2 X-CRM114-Status: GOOD ( 18.31 ) X-BeenThere: linux-arm-kernel@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-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Yicong Yang Currently if architectures want to support HOTPLUG_SMT they need to provide a topology_is_primary_thread() telling the framework which thread in the SMT cannot offline. However arm64 doesn't have a restriction on which thread in the SMT cannot offline, a simplest choice is that just make 1st thread as the "primary" thread. So just make this as the default implementation in the framework and let architectures like x86 that have special primary thread to override this function (which they've already done). There's no need to provide a stub function if !CONFIG_SMP or !CONFIG_HOTPLUG_SMT. In such case the testing CPU is already the 1st CPU in the SMT so it's always the primary thread. Reviewed-by: Jonathan Cameron Signed-off-by: Yicong Yang --- Pre questioned in v9 [1] whether this works on architectures not using CONFIG_GENERIC_ARCH_TOPOLOGY, See [2] for demonstration hacking on LoongArch VM and this also works. Architectures should use this on their own situation. [1] https://lore.kernel.org/linux-arm-kernel/427bd639-33c3-47e4-9e83-68c428eb1a7d@arm.com/ [2] https://lore.kernel.org/linux-arm-kernel/a5690fee-3019-f26c-8bad-1d95e388e877@huawei.com/ arch/powerpc/include/asm/topology.h | 1 + arch/x86/include/asm/topology.h | 2 +- include/linux/topology.h | 22 ++++++++++++++++++++++ 3 files changed, 24 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/topology.h b/arch/powerpc/include/asm/topology.h index 16bacfe8c7a2..da15b5efe807 100644 --- a/arch/powerpc/include/asm/topology.h +++ b/arch/powerpc/include/asm/topology.h @@ -152,6 +152,7 @@ static inline bool topology_is_primary_thread(unsigned int cpu) { return cpu == cpu_first_thread_sibling(cpu); } +#define topology_is_primary_thread topology_is_primary_thread static inline bool topology_smt_thread_allowed(unsigned int cpu) { diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h index ec134b719144..6c79ee7c0957 100644 --- a/arch/x86/include/asm/topology.h +++ b/arch/x86/include/asm/topology.h @@ -229,11 +229,11 @@ static inline bool topology_is_primary_thread(unsigned int cpu) { return cpumask_test_cpu(cpu, cpu_primary_thread_mask); } +#define topology_is_primary_thread topology_is_primary_thread #else /* CONFIG_SMP */ static inline int topology_phys_to_logical_pkg(unsigned int pkg) { return 0; } static inline int topology_max_smt_threads(void) { return 1; } -static inline bool topology_is_primary_thread(unsigned int cpu) { return true; } static inline unsigned int topology_amd_nodes_per_pkg(void) { return 1; } #endif /* !CONFIG_SMP */ diff --git a/include/linux/topology.h b/include/linux/topology.h index 52f5850730b3..b3aba443c4eb 100644 --- a/include/linux/topology.h +++ b/include/linux/topology.h @@ -240,6 +240,28 @@ static inline const struct cpumask *cpu_smt_mask(int cpu) } #endif +#ifndef topology_is_primary_thread + +#define topology_is_primary_thread topology_is_primary_thread + +static inline bool topology_is_primary_thread(unsigned int cpu) +{ + /* + * On SMT hotplug the primary thread of the SMT won't be disabled. + * Architectures do have a special primary thread (e.g. x86) need + * to override this function. Otherwise just make the first thread + * in the SMT as the primary thread. + * + * The sibling cpumask of an offline CPU contains always the CPU + * itself for architectures using CONFIG_GENERIC_ARCH_TOPOLOGY. + * Other architectures should use this depend on their own + * situation. + */ + return cpu == cpumask_first(topology_sibling_cpumask(cpu)); +} + +#endif + static inline const struct cpumask *cpu_cpu_mask(int cpu) { return cpumask_of_node(cpu_to_node(cpu)); From patchwork Tue Feb 18 14:10:16 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yicong Yang X-Patchwork-Id: 13979864 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 8E44AC02198 for ; Tue, 18 Feb 2025 14:17:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: Content-Transfer-Encoding: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=er/4MQhLp1s/XX6/1u00SmAi7p6++fwYiQ+bGsFQQBo=; b=OLEfTVJ2KPR53YH36gL7dTlq+g Q6QQ0olBQf5jG5ogFc4jlt4HQ1v1GQ5U1796eWRRIaMcFrkOo13PVq1m0s2nyBLtFekETQ9BiIwAa 3zE0rMnOic5zkX30Wlvvyxo1C6X+DATlQpLmudUN+pDUjDfW6opCT/ZVmGuYTbcEhI2pBxASulsRr Ir+8AavdngttIA8Gjvh+O+Y2J7gGGwFUOltY1h5wmrZKAZSjkmMaEZWdydSZSNdnn7d/GA+SvEw9g qXhvOojU20PSUvb2NOff1YcrcAvAFPMTSdQ6qNPM/tnHApWs/KwbyzZWwIAgkmmiZqilCZj2DLX3J YWo/tmIQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tkOPx-00000008TSC-2bIP; Tue, 18 Feb 2025 14:17:45 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tkOJ4-00000008RpF-0tfX for linux-arm-kernel@bombadil.infradead.org; Tue, 18 Feb 2025 14:10:38 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Type:Content-Transfer-Encoding :MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:CC:To:From: Sender:Reply-To:Content-ID:Content-Description; bh=er/4MQhLp1s/XX6/1u00SmAi7p6++fwYiQ+bGsFQQBo=; b=VEF221jFTnEKRBE8+PbqzVjLoN oe3MTnPiJP7DLh/1jckiKns9Fhv4eKgJ1W4RT8bHt/v3PtwLGWbC7BWIKSGVp1pj+2O+8DZH5l4/6 iFBN5m7/IZjCIRSFbIIdd6L9atqYZl/WATn3gCWzfUNbjZmqZXA0dYdCW0PheyPIZ8Y5EOryXpVF3 z67T6Up7w4yBKnn7rURmW4ThNhcxRkZaYogynh7yEjb4fSSWQINkRitZ6eodn6pJzY4cKOtCfTDmT smHS3USjplD0XviZ/CsktPbtvdykG4prPG+AmkCZQ64nxdI5tIQm49W69Mgxk2K/FbasGsKznCbUg LzHK3nKg==; Received: from szxga06-in.huawei.com ([45.249.212.32]) by desiato.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tkOIy-000000020EQ-3NAV for linux-arm-kernel@lists.infradead.org; Tue, 18 Feb 2025 14:10:36 +0000 Received: from mail.maildlp.com (unknown [172.19.88.214]) by szxga06-in.huawei.com (SkyGuard) with ESMTP id 4Yy1dW64SHzpkBd; Tue, 18 Feb 2025 22:10:39 +0800 (CST) Received: from kwepemd200014.china.huawei.com (unknown [7.221.188.8]) by mail.maildlp.com (Postfix) with ESMTPS id 2D0751A016C; Tue, 18 Feb 2025 22:10:09 +0800 (CST) Received: from localhost.localdomain (10.50.165.33) by kwepemd200014.china.huawei.com (7.221.188.8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.34; Tue, 18 Feb 2025 22:10:08 +0800 From: Yicong Yang To: , , , , , , , , , , , CC: , , , , , , , , , , , , , Subject: [PATCH v11 2/4] arch_topology: Support SMT control for OF based system Date: Tue, 18 Feb 2025 22:10:16 +0800 Message-ID: <20250218141018.18082-3-yangyicong@huawei.com> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20250218141018.18082-1-yangyicong@huawei.com> References: <20250218141018.18082-1-yangyicong@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.50.165.33] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To kwepemd200014.china.huawei.com (7.221.188.8) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250218_141035_178972_D76D337B X-CRM114-Status: GOOD ( 17.52 ) X-BeenThere: linux-arm-kernel@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-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Yicong Yang On building the topology from the devicetree, we've already gotten the SMT thread number of each core. Update the largest SMT thread number and enable the SMT control by the end of topology parsing. The core's SMT control provides two interface to the users [1]: 1) enable/disable SMT by writing on/off 2) enable/disable SMT by writing thread number 1/max_thread_number If a system have more than one SMT thread number the 2) may not handle it well, since there're multiple thread numbers in the system and 2) only accept 1/max_thread_number. So issue a warning to notify the users if such system detected. [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/ABI/testing/sysfs-devices-system-cpu#n542 Signed-off-by: Yicong Yang --- drivers/base/arch_topology.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c index 3ebe77566788..23f425a9d77a 100644 --- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include #include @@ -506,6 +507,10 @@ core_initcall(free_raw_capacity); #endif #if defined(CONFIG_ARM64) || defined(CONFIG_RISCV) + +/* Maximum SMT thread number detected used to enable the SMT control */ +static unsigned int max_smt_thread_num; + /* * This function returns the logic cpu number of the node. * There are basically three kinds of return values: @@ -565,6 +570,16 @@ static int __init parse_core(struct device_node *core, int package_id, i++; } while (1); + /* + * If max_smt_thread_num has been initialized and doesn't match + * the thread number of this entry, then the system has + * heterogeneous SMT topology. + */ + if (max_smt_thread_num && max_smt_thread_num != i) + pr_warn_once("Heterogeneous SMT topology is partly supported by SMT control\n"); + + max_smt_thread_num = max_t(unsigned int, max_smt_thread_num, i); + cpu = get_cpu_for_node(core); if (cpu >= 0) { if (!leaf) { @@ -677,6 +692,18 @@ static int __init parse_socket(struct device_node *socket) if (!has_socket) ret = parse_cluster(socket, 0, -1, 0); + /* + * Notify the CPU framework of the SMT support. Initialize the + * max_smt_thread_num to 1 if no SMT support detected or failed + * to parse the topology. A thread number of 1 can be handled by + * the framework so we don't need to check max_smt_thread_num to + * see we support SMT or not. + */ + if (!max_smt_thread_num || ret) + max_smt_thread_num = 1; + + cpu_smt_set_num_threads(max_smt_thread_num, max_smt_thread_num); + return ret; } From patchwork Tue Feb 18 14:10:17 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yicong Yang X-Patchwork-Id: 13979862 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 00903C02198 for ; Tue, 18 Feb 2025 14:14:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: Content-Transfer-Encoding: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=ofjcbTC5Iths2yPSWOVtIfXGjT3o/MqZin0E+e7oyZc=; b=TG5OgPMkUEtrs1iNFZTFlsGvJY Hq95r+xFiKtHIT6HnTg/cXSvagi2QI3hipsGOrFnaje/IfblxhBgqOx52olpTdUYhMJMHsHHFfcEG d7hjJhIUwTMQ9lvrygATarmDrih9cLHdzSBgCXOVPjMIH+NDJOljX89/QtMEJu6KrDu+NYFbYZeNJ moC6CG6TsUtNHuoKhzTrKAlb02BP+0iodDt079gVmv8H7Rri9F+OAbgWj500TyblvmaT0Kh1u/KYM 5TAQO7ps6+0g/NBd7KsZ1Nl4CjZrtmV/891oxQUKIpBq9rJrATF6aIWIjHGwlQrMWnYvmS0Fvp08T wURcqCUg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tkON4-00000008Sj7-42G3; Tue, 18 Feb 2025 14:14:46 +0000 Received: from szxga04-in.huawei.com ([45.249.212.190]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tkOIk-00000008RiS-1PNp for linux-arm-kernel@lists.infradead.org; Tue, 18 Feb 2025 14:10:20 +0000 Received: from mail.maildlp.com (unknown [172.19.163.44]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4Yy1YV4MQsz22wPM; Tue, 18 Feb 2025 22:07:10 +0800 (CST) Received: from kwepemd200014.china.huawei.com (unknown [7.221.188.8]) by mail.maildlp.com (Postfix) with ESMTPS id 0F5211401F1; Tue, 18 Feb 2025 22:10:10 +0800 (CST) Received: from localhost.localdomain (10.50.165.33) by kwepemd200014.china.huawei.com (7.221.188.8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.34; Tue, 18 Feb 2025 22:10:08 +0800 From: Yicong Yang To: , , , , , , , , , , , CC: , , , , , , , , , , , , , Subject: [PATCH v11 3/4] arm64: topology: Support SMT control on ACPI based system Date: Tue, 18 Feb 2025 22:10:17 +0800 Message-ID: <20250218141018.18082-4-yangyicong@huawei.com> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20250218141018.18082-1-yangyicong@huawei.com> References: <20250218141018.18082-1-yangyicong@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.50.165.33] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To kwepemd200014.china.huawei.com (7.221.188.8) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250218_061018_840908_89872C24 X-CRM114-Status: GOOD ( 23.03 ) X-BeenThere: linux-arm-kernel@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-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Yicong Yang For ACPI we'll build the topology from PPTT and we cannot directly get the SMT number of each core. Instead using a temporary xarray to record the heterogeneous information (from ACPI_PPTT_ACPI_IDENTICAL) and SMT information of the first core in its heterogeneous CPU cluster when building the topology. Then we can know the largest SMT number in the system. If a homogeneous system's using ACPI 6.2 or later, all the CPUs should be under the root node of PPTT. There'll be only one entry in the xarray and all the CPUs in the system will be assumed identical. The core's SMT control provides two interface to the users [1]: 1) enable/disable SMT by writing on/off 2) enable/disable SMT by writing thread number 1/max_thread_number If a system have more than one SMT thread number the 2) may not handle it well, since there're multiple thread numbers in the system and 2) only accept 1/max_thread_number. So issue a warning to notify the users if such system detected. [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/ABI/testing/sysfs-devices-system-cpu#n542 Reviewed-by: Jonathan Cameron Signed-off-by: Yicong Yang Reviewed-by: Hanjun Guo Reviewed-by: Pierre Gondois --- arch/arm64/kernel/topology.c | 66 ++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c index 1a2c72f3e7f8..6eba1ac091ee 100644 --- a/arch/arm64/kernel/topology.c +++ b/arch/arm64/kernel/topology.c @@ -15,8 +15,10 @@ #include #include #include +#include #include #include +#include #include #include @@ -37,17 +39,28 @@ static bool __init acpi_cpu_is_threaded(int cpu) return !!is_threaded; } +struct cpu_smt_info { + unsigned int thread_num; + int core_id; +}; + /* * Propagate the topology information of the processor_topology_node tree to the * cpu_topology array. */ int __init parse_acpi_topology(void) { + unsigned int max_smt_thread_num = 0; + struct cpu_smt_info *entry; + struct xarray hetero_cpu; + unsigned long hetero_id; int cpu, topology_id; if (acpi_disabled) return 0; + xa_init(&hetero_cpu); + for_each_possible_cpu(cpu) { topology_id = find_acpi_cpu_topology(cpu, 0); if (topology_id < 0) @@ -57,6 +70,34 @@ int __init parse_acpi_topology(void) cpu_topology[cpu].thread_id = topology_id; topology_id = find_acpi_cpu_topology(cpu, 1); cpu_topology[cpu].core_id = topology_id; + + /* + * In the PPTT, CPUs below a node with the 'identical + * implementation' flag have the same number of threads. + * Count the number of threads for only one CPU (i.e. + * one core_id) among those with the same hetero_id. + * See the comment of find_acpi_cpu_topology_hetero_id() + * for more details. + * + * One entry is created for each node having: + * - the 'identical implementation' flag + * - its parent not having the flag + */ + hetero_id = find_acpi_cpu_topology_hetero_id(cpu); + entry = xa_load(&hetero_cpu, hetero_id); + if (!entry) { + entry = kzalloc(sizeof(*entry), GFP_KERNEL); + WARN_ON_ONCE(!entry); + + if (entry) { + entry->core_id = topology_id; + entry->thread_num = 1; + xa_store(&hetero_cpu, hetero_id, + entry, GFP_KERNEL); + } + } else if (entry->core_id == topology_id) { + entry->thread_num++; + } } else { cpu_topology[cpu].thread_id = -1; cpu_topology[cpu].core_id = topology_id; @@ -67,6 +108,31 @@ int __init parse_acpi_topology(void) cpu_topology[cpu].package_id = topology_id; } + /* + * This should be a short loop depending on the number of heterogeneous + * CPU clusters. Typically on a homogeneous system there's only one + * entry in the XArray. + */ + xa_for_each(&hetero_cpu, hetero_id, entry) { + if (entry->thread_num != max_smt_thread_num && max_smt_thread_num) + pr_warn_once("Heterogeneous SMT topology is partly supported by SMT control\n"); + + max_smt_thread_num = max(max_smt_thread_num, entry->thread_num); + xa_erase(&hetero_cpu, hetero_id); + kfree(entry); + } + + /* + * Notify the CPU framework of the SMT support. Initialize the + * max_smt_thread_num to 1 if no SMT support detected. A thread + * number of 1 can be handled by the framework so we don't need + * to check max_smt_thread_num to see we support SMT or not. + */ + if (!max_smt_thread_num) + max_smt_thread_num = 1; + + cpu_smt_set_num_threads(max_smt_thread_num, max_smt_thread_num); + xa_destroy(&hetero_cpu); return 0; } #endif From patchwork Tue Feb 18 14:10:18 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yicong Yang X-Patchwork-Id: 13979863 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 EE1B4C021AA for ; Tue, 18 Feb 2025 14:16:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: Content-Transfer-Encoding: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=wKYgfTv9D+OpGZ+GA+Ok1Xs/9NJx+gQT6xO8EIyY3z4=; b=WwZzpHKdOnCo9KzXfmkY98x3nK 2q46TwgVoi5+bsi6QfvrkeW0HHGvLwSmO6l4oquHypV5atnUk66hAFXvn0wZo+FcWRwEAFIaRZk6M W2wHk9HKcEg3yCJfMV5DJNNvvI5laPbUgVIQaFsqEwzcwG92/1RJ0GVd5aE5mf3JuNKIAqoFx2qFL J4RueZLX4Fjeak9bQPoyDMoaf0sOE020E/zat/X7iBlKxPmaDhppZ5DOC24Iz/hapTc1MKJJ8eAt4 ZiDloQar5aJPUG4QepBPm4rocpFH9sBDX9rQP9rZH4l3VnmvIsexzBMJGVUon4l+b8QCipYe0m8i1 /hnroOig==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tkOOW-00000008T38-2u4e; Tue, 18 Feb 2025 14:16:16 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tkOJ2-00000008Rox-3xPz for linux-arm-kernel@bombadil.infradead.org; Tue, 18 Feb 2025 14:10:36 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Type:Content-Transfer-Encoding :MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:CC:To:From: Sender:Reply-To:Content-ID:Content-Description; bh=wKYgfTv9D+OpGZ+GA+Ok1Xs/9NJx+gQT6xO8EIyY3z4=; b=KqU/CVzbskkZgPrHwecTTKybHj OsOibL3fWDUPW+XN7esTxdfaVkie424L4yYNi2Sx98KVW+jTxJIQ7y88LDdOhDrH3Roi0jcksplbg P8/0W//a64dULom3+Y21L5sUvfhc0CXgFB63LfPpPRgrxdBhRoH/mNVzVxAyCHgWIjPtsfuCB80HS bpyj/6q9FIMcOI9m/Hh6YY0NymTQIygCuVgubkSEEqDTV8D2hvqYIIgRnTN4nNMi++B5iy01weLQX t1qsN+pgl+CTQr7HoQgyyJlDI01JatcXsD2xWbySFDFpTs47XEZfkFYu5Cc6U+53O6Bi+o189lUMy wlEl71cg==; Received: from szxga06-in.huawei.com ([45.249.212.32]) by desiato.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tkOIz-000000020EP-26y2 for linux-arm-kernel@lists.infradead.org; Tue, 18 Feb 2025 14:10:35 +0000 Received: from mail.maildlp.com (unknown [172.19.163.44]) by szxga06-in.huawei.com (SkyGuard) with ESMTP id 4Yy1dY4T6SzpkCN; Tue, 18 Feb 2025 22:10:41 +0800 (CST) Received: from kwepemd200014.china.huawei.com (unknown [7.221.188.8]) by mail.maildlp.com (Postfix) with ESMTPS id EA2EF1401F1; Tue, 18 Feb 2025 22:10:10 +0800 (CST) Received: from localhost.localdomain (10.50.165.33) by kwepemd200014.china.huawei.com (7.221.188.8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.34; Tue, 18 Feb 2025 22:10:09 +0800 From: Yicong Yang To: , , , , , , , , , , , CC: , , , , , , , , , , , , , Subject: [PATCH v11 4/4] arm64: Kconfig: Enable HOTPLUG_SMT Date: Tue, 18 Feb 2025 22:10:18 +0800 Message-ID: <20250218141018.18082-5-yangyicong@huawei.com> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20250218141018.18082-1-yangyicong@huawei.com> References: <20250218141018.18082-1-yangyicong@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.50.165.33] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To kwepemd200014.china.huawei.com (7.221.188.8) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250218_141034_124706_AE217381 X-CRM114-Status: UNSURE ( 6.54 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@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-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Yicong Yang Enable HOTPLUG_SMT for SMT control. Reviewed-by: Jonathan Cameron Signed-off-by: Yicong Yang --- arch/arm64/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index fcdd0ed3eca8..947616d37e0c 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -251,6 +251,7 @@ config ARM64 select HAVE_KRETPROBES select HAVE_GENERIC_VDSO select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU + select HOTPLUG_SMT if HOTPLUG_CPU select IRQ_DOMAIN select IRQ_FORCED_THREADING select KASAN_VMALLOC if KASAN