From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) (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 6C82A2F9DB2 for ; Thu, 18 Sep 2025 09:23:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.189 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758187420; cv=none; b=bPlUp4lOzxphsuyCU+1jj4Y3KDrul97UG7NnEytJIOCNmLazj31JjA5fm0Isf4eVyiMIiCmKRqws+mH4UoKXBxa3iS8zGXrnwegvtk1wkOVCtfsmWVKuYuvkiEkKhRGUB3kUoFHsLlsr1mHxY3KNbuE5BuTpYPjqPW9pv1e0gqc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758187420; c=relaxed/simple; bh=nkO9Kl8XPHS7wZBNuU9uqvFUkKXv3uCXoQDj2IkZLIo=; h=Subject:To:References:From:Message-ID:Date:MIME-Version: In-Reply-To:Content-Type; b=I4ULgPWammlk8P8Aq6dS2EPH5Paa31ppKDtekR6Ux2BhjaQs7s1CTYH/sEYbZK454Hg5HCyTGkEVklxkAHmJ7C2gte3DsmEQBdKhNQS2mMtJFrYGx93C+uZmkaqyhd0soGzW5obJI/j68qNpzG2fw/2T2szZtsAsmcVJiP6LekA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.189 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.163.48]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4cS9764xnDzPtWM; Thu, 18 Sep 2025 17:18:58 +0800 (CST) Received: from dggemv712-chm.china.huawei.com (unknown [10.1.198.32]) by mail.maildlp.com (Postfix) with ESMTPS id ABAAB1800B4; Thu, 18 Sep 2025 17:23:34 +0800 (CST) Received: from kwepemq200018.china.huawei.com (7.202.195.108) by dggemv712-chm.china.huawei.com (10.1.198.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Thu, 18 Sep 2025 17:23:34 +0800 Received: from [10.67.121.177] (10.67.121.177) by kwepemq200018.china.huawei.com (7.202.195.108) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Thu, 18 Sep 2025 17:23:33 +0800 Subject: Re: [PATCH v2] arch_topology: move parse_acpi_topology() to common code To: Yunhui Cui , , , , , , , , , , , , References: <20250918014828.78383-1-cuiyunhui@bytedance.com> From: Yicong Yang Message-ID: <0020389a-676c-74ab-b68f-cd0a44538980@huawei.com> Date: Thu, 18 Sep 2025 17:23:33 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.5.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <20250918014828.78383-1-cuiyunhui@bytedance.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: kwepems100001.china.huawei.com (7.221.188.238) To kwepemq200018.china.huawei.com (7.202.195.108) On 2025/9/18 9:48, Yunhui Cui wrote: > Currently, RISC-V lacks arch-specific registers for CPU topology > properties and must get them from ACPI. Thus, parse_acpi_topology() > is moved from arm64/ to drivers/ for RISC-V reuse. > > Signed-off-by: Yunhui Cui > --- > arch/arm64/kernel/topology.c | 87 +--------------------------------- > drivers/base/arch_topology.c | 89 ++++++++++++++++++++++++++++++++++- > include/linux/arch_topology.h | 1 + > 3 files changed, 90 insertions(+), 87 deletions(-) > > diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c > index 5d07ee85bdae4..55650db53b526 100644 > --- a/arch/arm64/kernel/topology.c > +++ b/arch/arm64/kernel/topology.c > @@ -26,7 +26,7 @@ > #include > > #ifdef CONFIG_ACPI > -static bool __init acpi_cpu_is_threaded(int cpu) > +bool __init acpi_cpu_is_threaded(int cpu) > { > int is_threaded = acpi_pptt_cpu_is_thread(cpu); > > @@ -39,91 +39,6 @@ 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 = 1; > - 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) > - return topology_id; > - > - if (acpi_cpu_is_threaded(cpu)) { > - 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; > - } > - topology_id = find_acpi_cpu_topology_cluster(cpu); > - cpu_topology[cpu].cluster_id = topology_id; > - topology_id = find_acpi_cpu_topology_package(cpu); > - cpu_topology[cpu].package_id = topology_id; > - } > - > - /* > - * This is a short loop since the number of XArray elements is the > - * number of heterogeneous CPU clusters. On a homogeneous system > - * there's only one entry in the XArray. > - */ > - xa_for_each(&hetero_cpu, hetero_id, entry) { > - max_smt_thread_num = max(max_smt_thread_num, entry->thread_num); > - xa_erase(&hetero_cpu, hetero_id); > - kfree(entry); > - } > - > - cpu_smt_set_num_threads(max_smt_thread_num, max_smt_thread_num); > - xa_destroy(&hetero_cpu); > - return 0; > -} > #endif > > #ifdef CONFIG_ARM64_AMU_EXTN > diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c > index 1037169abb459..c22746b45d57a 100644 > --- a/drivers/base/arch_topology.c > +++ b/drivers/base/arch_topology.c > @@ -823,12 +823,99 @@ void remove_cpu_topology(unsigned int cpu) > clear_cpu_topology(cpu); > } > > +__weak bool __init acpi_cpu_is_threaded(int cpu) > +{ > + int is_threaded = acpi_pptt_cpu_is_thread(cpu); > + > + return !!is_threaded; > +} > + you seem to miss the comment here in v1. acpi_pptt_cpu_is_thread() may return -ENOENT, in which case the CPU shouldn't be threaded? thanks.