From patchwork Wed Jan 4 18:30:23 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pierre Gondois X-Patchwork-Id: 13088831 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 219F3C4708D for ; Wed, 4 Jan 2023 18:32:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version: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:In-Reply-To:References: List-Owner; bh=nQPVPY16oBNpHCWeoyu5X7U5vd7zO3f4/WzP27jy/A0=; b=zji0S66yUo8F1x TUGgaW/avd9JeOiwOLAE3OpdjarwTbp/xTpJpSu4J4EQPV72TmwBhOWyCe1N3sItRKm5VzquzRbIE da4a/UZ2fHKkgz4lLul91KRHEIoLAXYPiqcXtsU4XB7TKYaadBGHQNqfqh+37HhAA93DCIWP6V1dN d+SGVt+Df1DY32gAHpIyMJP4uxK9UOmiok1D0NCG4ns7eGLlViMN7WELizLYNRYn9sMUJFD6d1qI8 3ZvuS5go+nWcPVmIOKzic/yXKxVhQe1aJ82/3S4bODxd9dS229WcluYkVY4l03WO8m2lB13+i70y+ zNxZ1+6Ue+se8j1RNn1w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pD8Xt-00AxTr-A3; Wed, 04 Jan 2023 18:31:36 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pD8Xl-00AxRi-H6; Wed, 04 Jan 2023 18:31:19 +0000 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 B09FB1063; Wed, 4 Jan 2023 10:31:53 -0800 (PST) Received: from pierre123.arm.com (unknown [10.57.44.105]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 706893F663; Wed, 4 Jan 2023 10:31:08 -0800 (PST) From: Pierre Gondois To: linux-kernel@vger.kernel.org Cc: Pierre Gondois , Catalin Marinas , Will Deacon , Paul Walmsley , Palmer Dabbelt , Albert Ou , "Rafael J. Wysocki" , Len Brown , Sudeep Holla , Greg Kroah-Hartman , Jeremy Linton , Conor Dooley , Gavin Shan , linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org, linux-acpi@vger.kernel.org Subject: [PATCH v4 0/6] arch_topology: Build cacheinfo from primary CPU Date: Wed, 4 Jan 2023 19:30:23 +0100 Message-Id: <20230104183033.755668-1-pierre.gondois@arm.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230104_103117_691615_A5E0E116 X-CRM114-Status: GOOD ( 12.81 ) 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 v2: - Applied renaming/formatting comments from v1. - Check CACHE_TYPE_VALID flag in pppt.c. v3: - Applied Sudeep's suggestions (for patch 5/5): - Renaming allocate_cache_info() -> fecth_cache_info() - Updated error message - Extract an inline allocate_cache_info() function - Re-run checkpatch with --strict option v4: - Remove RISC-V's implementation of init_cache_level() as not necessary. - Add patch: 'cacheinfo: Check 'cache-unified' property to count cache leaves' to increase the number of leaves at a cache level when no cache-size property is found. - In cacheinfo: Use RISC-V's init_cache_level() [...], make 'levels', 'leaves' and 'level' unsigned int to match of_property_read_u32()'s parameters signedness. Note: This patchset requires the following patch to be applied first in order to avoid the same bug described in the commit message: https://lore.kernel.org/all/20221116094958.2141072-1-pierre.gondois@arm.com/ [1] and [2] build the CPU topology from the cacheinfo information for both DT/ACPI based systems and remove (struct cpu_topology).llc_id which was used by ACPI only. Creating the cacheinfo for secondary CPUs is done during early boot. Preemption and interrupts are disabled at this stage. On PREEMPT_RT kernels, allocating memory (and parsing the PPTT table for ACPI based systems) triggers a: 'BUG: sleeping function called from invalid context' [4] To prevent this bug, allocate the cacheinfo from the primary CPU when preemption and interrupts are enabled and before booting secondary CPUs. The cache levels/leaves are computed from DT/ACPI PPTT information only, without relying on the arm64 CLIDR_EL1 register. If no cache information is found in the DT/ACPI PPTT, then fallback to the current state, triggering [4] on PREEMPT_RT kernels. Patches to update the arm64 device trees that have incomplete cacheinfo (mostly for missing the 'cache-level' or 'cache-unified' property) have been sent at [3]. Tested platforms: - ACPI + PPTT: Ampere Altra, Ampere eMAG, Cavium ThunderX2, Kunpeng 920, Juno-r2 - DT: rb5, db845c, Juno-r2 [1] https://lore.kernel.org/all/20220704101605.1318280-1-sudeep.holla@arm.com/ [2] https://lore.kernel.org/all/20220720-arch_topo_fixes-v3-0-43d696288e84@arm.com/ [3] https://lore.kernel.org/all/20221107155825.1644604-1-pierre.gondois@arm.com/ [4] On an Ampere Altra, with PREEMPT_RT kernel based on v6.0.0-rc4: [ 7.560791] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46 [ 7.560794] in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 0, name: swapper/111 [ 7.560796] preempt_count: 1, expected: 0 [ 7.560797] RCU nest depth: 1, expected: 1 [ 7.560799] 3 locks held by swapper/111/0: [ 7.560800] #0: ffff403e406cae98 (&pcp->lock){+.+.}-{3:3}, at: get_page_from_freelist+0x218/0x12c8 [ 7.560811] #1: ffffc5f8ed09f8e8 (rcu_read_lock){....}-{1:3}, at: rt_spin_trylock+0x48/0xf0 [ 7.560820] #2: ffff403f400b4fd8 (&zone->lock){+.+.}-{3:3}, at: rmqueue_bulk+0x64/0xa80 [ 7.560824] irq event stamp: 0 [ 7.560825] hardirqs last enabled at (0): [<0000000000000000>] 0x0 [ 7.560827] hardirqs last disabled at (0): [] copy_process+0x5dc/0x1ab8 [ 7.560830] softirqs last enabled at (0): [] copy_process+0x5dc/0x1ab8 [ 7.560833] softirqs last disabled at (0): [<0000000000000000>] 0x0 [ 7.560834] Preemption disabled at: [ 7.560835] [] migrate_enable+0x30/0x130 [ 7.560838] CPU: 111 PID: 0 Comm: swapper/111 Tainted: G W 6.0.0-rc4-[...] [ 7.560841] Call trace: [...] [ 7.560870] __kmalloc+0xbc/0x1e8 [ 7.560873] detect_cache_attributes+0x2d4/0x5f0 [ 7.560876] update_siblings_masks+0x30/0x368 [ 7.560880] store_cpu_topology+0x78/0xb8 [ 7.560883] secondary_start_kernel+0xd0/0x198 [ 7.560885] __secondary_switched+0xb0/0xb4 Pierre Gondois (6): cacheinfo: Use RISC-V's init_cache_level() as generic OF implementation cacheinfo: Return error code in init_of_cache_level() cacheinfo: Check 'cache-unified' property to count cache leaves ACPI: PPTT: Remove acpi_find_cache_levels() ACPI: PPTT: Update acpi_find_last_cache_level() to acpi_get_cache_info() arch_topology: Build cacheinfo from primary CPU arch/arm64/kernel/cacheinfo.c | 11 ++- arch/riscv/kernel/cacheinfo.c | 42 ----------- drivers/acpi/pptt.c | 93 +++++++++++++---------- drivers/base/arch_topology.c | 12 ++- drivers/base/cacheinfo.c | 134 +++++++++++++++++++++++++++++----- include/linux/cacheinfo.h | 11 ++- 6 files changed, 196 insertions(+), 107 deletions(-)