From patchwork Wed Jul 20 12:55:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sudeep Holla X-Patchwork-Id: 12923930 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DA12CC43334 for ; Wed, 20 Jul 2022 12:56:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237100AbiGTM4H (ORCPT ); Wed, 20 Jul 2022 08:56:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57566 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234243AbiGTM4D (ORCPT ); Wed, 20 Jul 2022 08:56:03 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id B281B252; Wed, 20 Jul 2022 05:56:02 -0700 (PDT) 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 02BD915A1; Wed, 20 Jul 2022 05:56:03 -0700 (PDT) Received: from usa.arm.com (e103737-lin.cambridge.arm.com [10.1.197.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id C81EA3F70D; Wed, 20 Jul 2022 05:56:00 -0700 (PDT) From: Sudeep Holla To: Sudeep Holla , "Rafael J. Wysocki" , Greg Kroah-Hartman Cc: Dietmar Eggemann , Pierre Gondois , linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org, Guenter Roeck , linux-acpi@vger.kernel.org, Conor Dooley , linux-kernel@vger.kernel.org, Geert Uytterhoeven , Ionela Voinescu Subject: [PATCH v3 1/3] cacheinfo: Use atomic allocation for percpu cache attributes Date: Wed, 20 Jul 2022 13:55:38 +0100 Message-Id: <20220720-arch_topo_fixes-v3-1-43d696288e84@arm.com> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220720-arch_topo_fixes-v3-0-43d696288e84@arm.com> References: <20220720-arch_topo_fixes-v3-0-43d696288e84@arm.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On couple of architectures like RISC-V and ARM64, we need to detect cache attribues quite early during the boot when the secondary CPUs start. So we will call detect_cache_attributes in the atomic context and since use of normal allocation can sleep, we will end up getting "sleeping in the atomic context" bug splat. In order avoid that, move the allocation to use atomic version in preparation to move the actual detection of cache attributes in the CPU hotplug path which is atomic. Cc: Ionela Voinescu Tested-by: Conor Dooley Signed-off-by: Sudeep Holla diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c index 65d566ff24c4..4b5cd08c5a65 100644 --- a/drivers/base/cacheinfo.c +++ b/drivers/base/cacheinfo.c @@ -356,7 +356,7 @@ int detect_cache_attributes(unsigned int cpu) return -ENOENT; per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu), - sizeof(struct cacheinfo), GFP_KERNEL); + sizeof(struct cacheinfo), GFP_ATOMIC); if (per_cpu_cacheinfo(cpu) == NULL) { cache_leaves(cpu) = 0; return -ENOMEM; From patchwork Wed Jul 20 12:55:39 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sudeep Holla X-Patchwork-Id: 12923931 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 38281CCA485 for ; Wed, 20 Jul 2022 12:56:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238253AbiGTM4H (ORCPT ); Wed, 20 Jul 2022 08:56:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57594 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236854AbiGTM4F (ORCPT ); Wed, 20 Jul 2022 08:56:05 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 8DD93140FA; Wed, 20 Jul 2022 05:56:04 -0700 (PDT) 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 D5C3C15BF; Wed, 20 Jul 2022 05:56:04 -0700 (PDT) Received: from usa.arm.com (e103737-lin.cambridge.arm.com [10.1.197.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id AFC883F70D; Wed, 20 Jul 2022 05:56:02 -0700 (PDT) From: Sudeep Holla To: Sudeep Holla , "Rafael J. Wysocki" , Greg Kroah-Hartman Cc: Dietmar Eggemann , Pierre Gondois , linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org, Guenter Roeck , linux-acpi@vger.kernel.org, Conor Dooley , linux-kernel@vger.kernel.org, Geert Uytterhoeven , Ionela Voinescu Subject: [PATCH v3 2/3] ACPI: PPTT: Leave the table mapped for the runtime usage Date: Wed, 20 Jul 2022 13:55:39 +0100 Message-Id: <20220720-arch_topo_fixes-v3-2-43d696288e84@arm.com> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220720-arch_topo_fixes-v3-0-43d696288e84@arm.com> References: <20220720-arch_topo_fixes-v3-0-43d696288e84@arm.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org Currently, everytime an information needs to be fetched from the PPTT, the table is mapped via acpi_get_table() and unmapped after the use via acpi_put_table() which is fine. However we do this at runtime especially when the CPU is hotplugged out and plugged in back since we re-populate the cache topology and other information. However, with the support to fetch LLC information from the PPTT in the cpuhotplug path which is executed in the atomic context, it is preferred to avoid mapping and unmapping of the PPTT for every single use as the acpi_get_table() might sleep waiting for a mutex. In order to avoid the same, the table is needs to just mapped once on the boot CPU and is never unmapped allowing it to be used at runtime with out the hassle of mapping and unmapping the table. Reported-by: Guenter Roeck Cc: Rafael J. Wysocki Signed-off-by: Sudeep Holla Acked-by: Rafael J. Wysocki --- Hi Rafael, Sorry to bother you again on this PPTT changes. Guenter reported an issue with lockdep enabled in -next that include my cacheinfo/arch_topology changes to utilise LLC from PPTT in the CPU hotplug path. Please ack the change once you are happy so that I can get it merged with other fixes via Greg's tree. Regards, Sudeep diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c index dd3222a15c9c..c91342dcbcd6 100644 --- a/drivers/acpi/pptt.c +++ b/drivers/acpi/pptt.c @@ -533,21 +533,37 @@ static int topology_get_acpi_cpu_tag(struct acpi_table_header *table, return -ENOENT; } + +static struct acpi_table_header *acpi_get_pptt(void) +{ + static struct acpi_table_header *pptt; + acpi_status status; + + /* + * PPTT will be used at runtime on every CPU hotplug in path, so we + * don't need to call acpi_put_table() to release the table mapping. + */ + if (!pptt) { + status = acpi_get_table(ACPI_SIG_PPTT, 0, &pptt); + if (ACPI_FAILURE(status)) + acpi_pptt_warn_missing(); + } + + return pptt; +} + static int find_acpi_cpu_topology_tag(unsigned int cpu, int level, int flag) { struct acpi_table_header *table; - acpi_status status; int retval; - status = acpi_get_table(ACPI_SIG_PPTT, 0, &table); - if (ACPI_FAILURE(status)) { - acpi_pptt_warn_missing(); + table = acpi_get_pptt(); + if (!table) return -ENOENT; - } + retval = topology_get_acpi_cpu_tag(table, cpu, level, flag); pr_debug("Topology Setup ACPI CPU %d, level %d ret = %d\n", cpu, level, retval); - acpi_put_table(table); return retval; } @@ -568,16 +584,13 @@ static int find_acpi_cpu_topology_tag(unsigned int cpu, int level, int flag) static int check_acpi_cpu_flag(unsigned int cpu, int rev, u32 flag) { struct acpi_table_header *table; - acpi_status status; u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu); struct acpi_pptt_processor *cpu_node = NULL; int ret = -ENOENT; - status = acpi_get_table(ACPI_SIG_PPTT, 0, &table); - if (ACPI_FAILURE(status)) { - acpi_pptt_warn_missing(); - return ret; - } + table = acpi_get_pptt(); + if (!table) + return -ENOENT; if (table->revision >= rev) cpu_node = acpi_find_processor_node(table, acpi_cpu_id); @@ -585,8 +598,6 @@ static int check_acpi_cpu_flag(unsigned int cpu, int rev, u32 flag) if (cpu_node) ret = (cpu_node->flags & flag) != 0; - acpi_put_table(table); - return ret; } @@ -605,18 +616,15 @@ int acpi_find_last_cache_level(unsigned int cpu) u32 acpi_cpu_id; struct acpi_table_header *table; int number_of_levels = 0; - acpi_status status; + + table = acpi_get_pptt(); + if (!table) + return -ENOENT; pr_debug("Cache Setup find last level CPU=%d\n", cpu); acpi_cpu_id = get_acpi_id_for_cpu(cpu); - status = acpi_get_table(ACPI_SIG_PPTT, 0, &table); - if (ACPI_FAILURE(status)) { - acpi_pptt_warn_missing(); - } else { - number_of_levels = acpi_find_cache_levels(table, acpi_cpu_id); - acpi_put_table(table); - } + number_of_levels = acpi_find_cache_levels(table, acpi_cpu_id); pr_debug("Cache Setup find last level level=%d\n", number_of_levels); return number_of_levels; @@ -638,20 +646,16 @@ int acpi_find_last_cache_level(unsigned int cpu) int cache_setup_acpi(unsigned int cpu) { struct acpi_table_header *table; - acpi_status status; - - pr_debug("Cache Setup ACPI CPU %d\n", cpu); - status = acpi_get_table(ACPI_SIG_PPTT, 0, &table); - if (ACPI_FAILURE(status)) { - acpi_pptt_warn_missing(); + table = acpi_get_pptt(); + if (!table) return -ENOENT; - } + + pr_debug("Cache Setup ACPI CPU %d\n", cpu); cache_setup_acpi_cpu(table, cpu); - acpi_put_table(table); - return status; + return 0; } /** @@ -730,50 +734,38 @@ int find_acpi_cpu_topology_package(unsigned int cpu) int find_acpi_cpu_topology_cluster(unsigned int cpu) { struct acpi_table_header *table; - acpi_status status; struct acpi_pptt_processor *cpu_node, *cluster_node; u32 acpi_cpu_id; int retval; int is_thread; - status = acpi_get_table(ACPI_SIG_PPTT, 0, &table); - if (ACPI_FAILURE(status)) { - acpi_pptt_warn_missing(); + table = acpi_get_pptt(); + if (!table) return -ENOENT; - } acpi_cpu_id = get_acpi_id_for_cpu(cpu); cpu_node = acpi_find_processor_node(table, acpi_cpu_id); - if (cpu_node == NULL || !cpu_node->parent) { - retval = -ENOENT; - goto put_table; - } + if (!cpu_node || !cpu_node->parent) + return -ENOENT; is_thread = cpu_node->flags & ACPI_PPTT_ACPI_PROCESSOR_IS_THREAD; cluster_node = fetch_pptt_node(table, cpu_node->parent); - if (cluster_node == NULL) { - retval = -ENOENT; - goto put_table; - } + if (!cluster_node) + return -ENOENT; + if (is_thread) { - if (!cluster_node->parent) { - retval = -ENOENT; - goto put_table; - } + if (!cluster_node->parent) + return -ENOENT; + cluster_node = fetch_pptt_node(table, cluster_node->parent); - if (cluster_node == NULL) { - retval = -ENOENT; - goto put_table; - } + if (!cluster_node) + return -ENOENT; } if (cluster_node->flags & ACPI_PPTT_ACPI_PROCESSOR_ID_VALID) retval = cluster_node->acpi_processor_id; else retval = ACPI_PTR_DIFF(cluster_node, table); -put_table: - acpi_put_table(table); - return retval; } From patchwork Wed Jul 20 12:55:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sudeep Holla X-Patchwork-Id: 12923932 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 17303C433EF for ; Wed, 20 Jul 2022 12:56:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240478AbiGTM4T (ORCPT ); Wed, 20 Jul 2022 08:56:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57630 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237447AbiGTM4H (ORCPT ); Wed, 20 Jul 2022 08:56:07 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 6AD5C3F31A; Wed, 20 Jul 2022 05:56:06 -0700 (PDT) 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 B593615DB; Wed, 20 Jul 2022 05:56:06 -0700 (PDT) Received: from usa.arm.com (e103737-lin.cambridge.arm.com [10.1.197.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 8FBD63F70D; Wed, 20 Jul 2022 05:56:04 -0700 (PDT) From: Sudeep Holla To: Sudeep Holla , "Rafael J. Wysocki" , Greg Kroah-Hartman Cc: Dietmar Eggemann , Pierre Gondois , linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org, Guenter Roeck , linux-acpi@vger.kernel.org, Conor Dooley , linux-kernel@vger.kernel.org, Geert Uytterhoeven , Ionela Voinescu Subject: [PATCH v3 3/3] arch_topology: Fix cache attributes detection in the CPU hotplug path Date: Wed, 20 Jul 2022 13:55:40 +0100 Message-Id: <20220720-arch_topo_fixes-v3-3-43d696288e84@arm.com> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220720-arch_topo_fixes-v3-0-43d696288e84@arm.com> References: <20220720-arch_topo_fixes-v3-0-43d696288e84@arm.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org init_cpu_topology() is called only once at the boot and all the cache attributes are detected early for all the possible CPUs. However when the CPUs are hotplugged out, the cacheinfo gets removed. While the attributes are added back when the CPUs are hotplugged back in as part of CPU hotplug state machine, it ends up called quite late after the update_siblings_masks() are called in the secondary_start_kernel() resulting in wrong llc_sibling_masks. Move the call to detect_cache_attributes() inside update_siblings_masks() to ensure the cacheinfo is updated before the LLC sibling masks are updated. This will fix the incorrect LLC sibling masks generated when the CPUs are hotplugged out and hotplugged back in again. Reported-by: Ionela Voinescu Reviewed-by: Conor Dooley Reviewed-by: Ionela Voinescu Tested-by: Geert Uytterhoeven Tested-by: Ionela Voinescu Signed-off-by: Sudeep Holla diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c index 441e14ac33a4..0424b59b695e 100644 --- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -732,7 +732,11 @@ const struct cpumask *cpu_clustergroup_mask(int cpu) void update_siblings_masks(unsigned int cpuid) { struct cpu_topology *cpu_topo, *cpuid_topo = &cpu_topology[cpuid]; - int cpu; + int cpu, ret; + + ret = detect_cache_attributes(cpuid); + if (ret) + pr_info("Early cacheinfo failed, ret = %d\n", ret); /* update core and thread sibling masks */ for_each_online_cpu(cpu) { @@ -821,7 +825,7 @@ __weak int __init parse_acpi_topology(void) #if defined(CONFIG_ARM64) || defined(CONFIG_RISCV) void __init init_cpu_topology(void) { - int ret, cpu; + int ret; reset_cpu_topology(); ret = parse_acpi_topology(); @@ -836,13 +840,5 @@ void __init init_cpu_topology(void) reset_cpu_topology(); return; } - - for_each_possible_cpu(cpu) { - ret = detect_cache_attributes(cpu); - if (ret) { - pr_info("Early cacheinfo failed, ret = %d\n", ret); - break; - } - } } #endif