From patchwork Fri Dec 9 10:31:22 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pierre Gondois X-Patchwork-Id: 632914 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 7B3B0C4332F for ; Fri, 9 Dec 2022 10:32:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229660AbiLIKcj (ORCPT ); Fri, 9 Dec 2022 05:32:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50842 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229735AbiLIKc3 (ORCPT ); Fri, 9 Dec 2022 05:32:29 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4CCBF6ACFC; Fri, 9 Dec 2022 02:32:28 -0800 (PST) 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 BEA1223A; Fri, 9 Dec 2022 02:32:34 -0800 (PST) Received: from pierre123.arm.com (unknown [10.57.42.27]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id CF3663F73B; Fri, 9 Dec 2022 02:32:23 -0800 (PST) From: Pierre Gondois To: linux-kernel@vger.kernel.org Cc: palmer@rivosinc.com, Ionela.Voinescu@arm.com, 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 v3 0/5] arch_topology: Build cacheinfo from primary CPU Date: Fri, 9 Dec 2022 11:31:22 +0100 Message-Id: <20221209103130.572196-1-pierre.gondois@arm.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.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 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 (5): cacheinfo: Use RISC-V's init_cache_level() as generic OF implementation cacheinfo: Return error code in init_of_cache_level() 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 | 39 +---------- drivers/acpi/pptt.c | 93 +++++++++++++++----------- drivers/base/arch_topology.c | 12 +++- drivers/base/cacheinfo.c | 119 +++++++++++++++++++++++++++++----- include/linux/cacheinfo.h | 11 +++- 6 files changed, 182 insertions(+), 103 deletions(-)