From mboxrd@z Thu Jan 1 00:00:00 1970 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 7DB92CCFA05 for ; Sat, 8 Nov 2025 04:32:08 +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-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Gf3dtK9whnvoieMQrk7xUOMK4ZkLioSOkS+mxb2q8k8=; b=BguyKAKLyQRliWKPGn1+j3uWsv wNW7Ig77qoO9vJfcr5qUlqj+HLo2PoB3WsziG03RcN729tHEWA4jrw3RFGehGMmcr6nMjQeArzgeu xhO8sP/qDgDcdkyM8B2KqhtA4IIwjA604pdXIKHzOiYLehd+rEIMK5K33d2gzTfrbGC7muO03lz7y Xk2npS7ApsYlRydKg9k1K3gQeDbhYluvviL/MfCJp6GJPlHRPK7q5lLkngZ9zcw2r9+NNwsXsK5mG WflaNlWsKmibW31zYnH3+mNK127MCccjGn/cIUg8nhYJGLw4M7GJH/4aATNdELTkxzlM3ZTUu8tCs hogolFhg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vHacE-00000002VjS-2dnJ; Sat, 08 Nov 2025 04:31:54 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vHac9-00000002Via-2KCy for linux-arm-kernel@lists.infradead.org; Sat, 08 Nov 2025 04:31:53 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1762576305; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Gf3dtK9whnvoieMQrk7xUOMK4ZkLioSOkS+mxb2q8k8=; b=BFK/RhjYE4Mfs/uB9b8NxKmCdFG6Ll4tYKxqSyXXcGBdzp1JIZBYt9nc5j/OX9N3dKhUL+ 2C0HUslAUVnyZ6lbkoSDWDjyJkEQG1IlSGNzHw+WqAsdsdnqf5nL0Ll3SvGRABKcxq7EHe VfzZy1X5LUUGT9yH5O7RXS+fKhVZHrk= Received: from mail-pl1-f199.google.com (mail-pl1-f199.google.com [209.85.214.199]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-426-qjh31wi4N2SBANw4SG351Q-1; Fri, 07 Nov 2025 23:31:43 -0500 X-MC-Unique: qjh31wi4N2SBANw4SG351Q-1 X-Mimecast-MFC-AGG-ID: qjh31wi4N2SBANw4SG351Q_1762576303 Received: by mail-pl1-f199.google.com with SMTP id d9443c01a7336-2956a694b47so18841185ad.1 for ; Fri, 07 Nov 2025 20:31:43 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1762576303; x=1763181103; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=Gf3dtK9whnvoieMQrk7xUOMK4ZkLioSOkS+mxb2q8k8=; b=iut9WF87zQTdA1cIPJVqIFFdFqT6WNRWfg+uc0jOQZcVUg0spX3OiSlFVW1w5sLq5E r2xR7qa8LgxgsZytP5WBcys1cMAdydr/fL8t7OUiTCCVubOAOkgysAWdRvYrQHyKjheV uL4xNPvdC0XVWLNzF1G1UXmfg+lWJNJnhNws79dehwq28r01MyuLNh3o26JPfEK+NMkq O8pz/jgcpcRwH6Bj0ITmdSpibx3xc9gjzSG7aXuXEcbsVhgkNH6NQwmzTiAD+bcDRzoh VSkDMkDxzip04RNXjoRRqM8/es8hOb2P/MroKT+ebPg8aRvaulacLqK0CfisBylck/dp F6ig== X-Forwarded-Encrypted: i=1; AJvYcCUtQ9P7j/Mz+7PxE6i3A1wKZKjhUQVlmdcj4ArJ3dBY4615ki6XR7iEHUyvxBmDZyXcii6pyVvqJE59/I2vrFHL@lists.infradead.org X-Gm-Message-State: AOJu0YzoahdnwiZdvYje7xMgSteN17BRiijl6VBgqGe0dxNx4qQRacHI XCoCXeIJa3U9WGWi71niC8R7T9RWvIBxt40+Ja+CwwqbgpMIAi7hgt7X/nNFG/Xrc74QStySQTj WjjNulJWqH93RQL9MHh7G2WDj6BmkBWv60K23KP0OF4vkfVZvZSB78V5Z+xUhaWhL2AxVnQg7ol MJ X-Gm-Gg: ASbGnctj+J2/WETUqiOLod6Ft1LaQy34OVR2PSYxqY7pcc2pZEeNsMgwRmc26a6yGUE Osxdr5sEanovE62WzI59S4PT2fwOxpzuGPoiNjrV2Q16NSVGArE2jJxCNE02vA4ibbWY8iUpmR8 J+BrAvj1SHWCIZz2hS/WKNkp3n/Bs3DIYShPateislYdufGO2TrIKsGV1NxQ0dczLmTnOcOccif X9ZVHHcQgr3M7apw9efb971VLJ0p5cXzmVWNgs3R6Jh3r3syooxnXg6U/P3H+K8FNPrhzG3P006 0Q1TXbRQh41UFNayYxJB0o+VIyv0AiTSmW9vpnUSlZtmarPZV5Q/7dvipTAPHgUewIUt41Fy0r1 LC2YWYR1fejfTT4Gkmt+dHbOequWm4LJiJXVzENU= X-Received: by 2002:a17:903:40c9:b0:295:56da:62a4 with SMTP id d9443c01a7336-297e56caea4mr15886695ad.45.1762576302814; Fri, 07 Nov 2025 20:31:42 -0800 (PST) X-Google-Smtp-Source: AGHT+IHQTitOB0enfK3OsnV3JV6rJIse5pQU20FSNU11DFWBQoFKK5PuvCsMDdw2vNkdjw8y8BgN8Q== X-Received: by 2002:a17:903:40c9:b0:295:56da:62a4 with SMTP id d9443c01a7336-297e56caea4mr15886445ad.45.1762576302385; Fri, 07 Nov 2025 20:31:42 -0800 (PST) Received: from [192.168.68.51] (n175-34-62-5.mrk21.qld.optusnet.com.au. [175.34.62.5]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-29651cd0ee9sm76355185ad.112.2025.11.07.20.31.30 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 07 Nov 2025 20:31:41 -0800 (PST) Message-ID: <11f80800-2e0b-4f41-a022-a88ad9792da8@redhat.com> Date: Sat, 8 Nov 2025 14:31:28 +1000 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 01/33] ACPI / PPTT: Add a helper to fill a cpumask from a processor container To: Ben Horgan , james.morse@arm.com Cc: amitsinght@marvell.com, baisheng.gao@unisoc.com, baolin.wang@linux.alibaba.com, bobo.shaobowang@huawei.com, carl@os.amperecomputing.com, catalin.marinas@arm.com, dakr@kernel.org, dave.martin@arm.com, david@redhat.com, dfustini@baylibre.com, fenghuay@nvidia.com, gregkh@linuxfoundation.org, guohanjun@huawei.com, jeremy.linton@arm.com, jonathan.cameron@huawei.com, kobak@nvidia.com, lcherian@marvell.com, lenb@kernel.org, linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, lpieralisi@kernel.org, peternewman@google.com, quic_jiles@quicinc.com, rafael@kernel.org, robh@kernel.org, rohit.mathew@arm.com, scott@os.amperecomputing.com, sdonthineni@nvidia.com, sudeep.holla@arm.com, tan.shaopeng@fujitsu.com, will@kernel.org, xhao@linux.alibaba.com, Shaopeng Tan References: <20251107123450.664001-1-ben.horgan@arm.com> <20251107123450.664001-2-ben.horgan@arm.com> From: Gavin Shan In-Reply-To: <20251107123450.664001-2-ben.horgan@arm.com> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: mF-iTfU8yw27NhZYjln5JpDi6L8di9QYnZ46RyLXbXU_1762576303 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251107_203150_022180_5B86F4E0 X-CRM114-Status: GOOD ( 29.43 ) 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 Hi Ben, On 11/7/25 10:34 PM, Ben Horgan wrote: > From: James Morse > > The ACPI MPAM table uses the UID of a processor container specified in > the PPTT to indicate the subset of CPUs and cache topology that can > access each MPAM System Component (MSC). > > This information is not directly useful to the kernel. The equivalent > cpumask is needed instead. > > Add a helper to find the processor container by its id, then walk > the possible CPUs to fill a cpumask with the CPUs that have this > processor container as a parent. > > CC: Dave Martin > Reviewed-by: Sudeep Holla > Reviewed-by: Jonathan Cameron > Reviewed-by: Fenghua Yu > Reviewed-by: Gavin Shan > Tested-by: Fenghua Yu > Tested-by: Shaopeng Tan > Tested-by: Peter Newman > Signed-off-by: James Morse > Signed-off-by: Ben Horgan > --- > Changes since v3: > Refer to processor hierarchy in comments (Jonathan) > Fix indent (Jonathan) > --- > drivers/acpi/pptt.c | 85 ++++++++++++++++++++++++++++++++++++++++++++ > include/linux/acpi.h | 3 ++ > 2 files changed, 88 insertions(+) > Two nitpicks below... > diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c > index 54676e3d82dd..69917cc6bd2f 100644 > --- a/drivers/acpi/pptt.c > +++ b/drivers/acpi/pptt.c > @@ -817,3 +817,88 @@ int find_acpi_cpu_topology_hetero_id(unsigned int cpu) > return find_acpi_cpu_topology_tag(cpu, PPTT_ABORT_PACKAGE, > ACPI_PPTT_ACPI_IDENTICAL); > } > + > +/** > + * acpi_pptt_get_child_cpus() - Find all the CPUs below a PPTT > + * processor hierarchy node > + * > + * @table_hdr: A reference to the PPTT table > + * @parent_node: A pointer to the processor hierarchy node in the > + * table_hdr > + * @cpus: A cpumask to fill with the CPUs below @parent_node > + * > + * Walks up the PPTT from every possible CPU to find if the provided > + * @parent_node is a parent of this CPU. > + */ > +static void acpi_pptt_get_child_cpus(struct acpi_table_header *table_hdr, > + struct acpi_pptt_processor *parent_node, > + cpumask_t *cpus) > +{ > + struct acpi_pptt_processor *cpu_node; > + u32 acpi_id; > + int cpu; > + > + cpumask_clear(cpus); > + > + for_each_possible_cpu(cpu) { > + acpi_id = get_acpi_id_for_cpu(cpu); > + cpu_node = acpi_find_processor_node(table_hdr, acpi_id); > + > + while (cpu_node) { > + if (cpu_node == parent_node) { > + cpumask_set_cpu(cpu, cpus); > + break; > + } > + cpu_node = fetch_pptt_node(table_hdr, cpu_node->parent); > + } > + } > +} > + > +/** > + * acpi_pptt_get_cpus_from_container() - Populate a cpumask with all CPUs in a > + * processor container > + * @acpi_cpu_id: The UID of the processor container > + * @cpus: The resulting CPU mask > + * > + * Find the specified Processor Container, and fill @cpus with all the cpus > + * below it. > + * > + * Not all 'Processor Hierarchy' entries in the PPTT are either a CPU > + * or a Processor Container, they may exist purely to describe a > + * Private resource. CPUs have to be leaves, so a Processor Container > + * is a non-leaf that has the 'ACPI Processor ID valid' flag set. > + */ > +void acpi_pptt_get_cpus_from_container(u32 acpi_cpu_id, cpumask_t *cpus) > +{ > + struct acpi_table_header *table_hdr; > + struct acpi_subtable_header *entry; > + unsigned long table_end; > + u32 proc_sz; > + > + cpumask_clear(cpus); > + > + table_hdr = acpi_get_pptt(); > + if (!table_hdr) > + return; > + > + table_end = (unsigned long)table_hdr + table_hdr->length; > + entry = ACPI_ADD_PTR(struct acpi_subtable_header, table_hdr, > + sizeof(struct acpi_table_pptt)); > + proc_sz = sizeof(struct acpi_pptt_processor); > + while ((unsigned long)entry + proc_sz <= table_end) { > + Unnecessary blank line here. > + if (entry->type == ACPI_PPTT_TYPE_PROCESSOR) { > + struct acpi_pptt_processor *cpu_node; > + > + cpu_node = (struct acpi_pptt_processor *)entry; > + if (cpu_node->flags & ACPI_PPTT_ACPI_PROCESSOR_ID_VALID && > + !acpi_pptt_leaf_node(table_hdr, cpu_node) && > + cpu_node->acpi_processor_id == acpi_cpu_id) { > + acpi_pptt_get_child_cpus(table_hdr, cpu_node, cpus); > + break; > + } > + } > + entry = ACPI_ADD_PTR(struct acpi_subtable_header, entry, > + entry->length); Need we to check if @cpu_node does crosses the boundary (@table_end), as what's doing in acpi_find_processor_node()? Actually, the similar hunk of code from the function can be reused here. static struct acpi_pptt_processor *acpi_find_processor_node(struct acpi_table_header *table_hdr, u32 acpi_cpu_id) { : while ((unsigned long)entry + proc_sz <= table_end) { cpu_node = (struct acpi_pptt_processor *)entry; if (entry->length == 0) { pr_warn("Invalid zero length subtable\n"); break; } /* entry->length may not equal proc_sz, revalidate the processor structure length */ if (entry->type == ACPI_PPTT_TYPE_PROCESSOR && acpi_cpu_id == cpu_node->acpi_processor_id && (unsigned long)entry + entry->length <= table_end && entry->length == proc_sz + cpu_node->number_of_priv_resources * sizeof(u32) && acpi_pptt_leaf_node(table_hdr, cpu_node)) { return (struct acpi_pptt_processor *)entry; } entry = ACPI_ADD_PTR(struct acpi_subtable_header, entry, entry->length); } : } > + } > +} > diff --git a/include/linux/acpi.h b/include/linux/acpi.h > index 5ff5d99f6ead..4752ebd48132 100644 > --- a/include/linux/acpi.h > +++ b/include/linux/acpi.h > @@ -1541,6 +1541,7 @@ int find_acpi_cpu_topology(unsigned int cpu, int level); > int find_acpi_cpu_topology_cluster(unsigned int cpu); > int find_acpi_cpu_topology_package(unsigned int cpu); > int find_acpi_cpu_topology_hetero_id(unsigned int cpu); > +void acpi_pptt_get_cpus_from_container(u32 acpi_cpu_id, cpumask_t *cpus); > #else > static inline int acpi_pptt_cpu_is_thread(unsigned int cpu) > { > @@ -1562,6 +1563,8 @@ static inline int find_acpi_cpu_topology_hetero_id(unsigned int cpu) > { > return -EINVAL; > } > +static inline void acpi_pptt_get_cpus_from_container(u32 acpi_cpu_id, > + cpumask_t *cpus) { } > #endif > > void acpi_arch_init(void); Thanks, Gavin