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 4C8DFC61DA4 for ; Wed, 15 Mar 2023 05:17:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231683AbjCOFRL (ORCPT ); Wed, 15 Mar 2023 01:17:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49234 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231400AbjCOFPX (ORCPT ); Wed, 15 Mar 2023 01:15:23 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id CADB42BF03; Tue, 14 Mar 2023 22:14:58 -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 BFFA32F4; Tue, 14 Mar 2023 22:15:41 -0700 (PDT) Received: from a077893.blr.arm.com (unknown [10.162.41.10]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 5192E3F67D; Tue, 14 Mar 2023 22:14:53 -0700 (PDT) From: Anshuman Khandual To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, will@kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com Cc: Anshuman Khandual , Mark Brown , James Clark , Rob Herring , Marc Zyngier , Suzuki Poulose , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , linux-perf-users@vger.kernel.org Subject: [PATCH V9 00/10] arm64/perf: Enable branch stack sampling Date: Wed, 15 Mar 2023 10:44:34 +0530 Message-Id: <20230315051444.1683170-1-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This series enables perf branch stack sampling support on arm64 platform via a new arch feature called Branch Record Buffer Extension (BRBE). All relevant register definitions could be accessed here. https://developer.arm.com/documentation/ddi0601/2021-12/AArch64-Registers This series applies on 6.3-rc1 after applying the following patch from Mark which allows enums in SysregFields blocks in sysreg tools. https://lore.kernel.org/all/20230306114836.2575432-1-mark.rutland@arm.com/ Changes in V9: - Fixed build problem with has_branch_stack() in arm64 header - BRBINF_EL1 definition has been changed from 'Sysreg' to 'SysregFields' - Renamed all BRBINF_EL1 call sites as BRBINFx_EL1 - Dropped static const char branch_filter_error_msg[] - Implemented a positive list check for BRBE supported perf branch filters - Added a comment in armv8pmu_handle_irq() - Implemented per-cpu allocation for struct branch_record records - Skipped looping through bank 1 if an invalid record is detected in bank 0 - Added comment in armv8pmu_branch_read() explaining prohibited region etc - Added comment warning about erroneously marking transactions as aborted - Replaced the first argument (perf_branch_entry) in capture_brbe_flags() - Dropped the last argument (idx) in capture_brbe_flags() - Dropped the brbcr argument from capture_brbe_flags() - Used perf_sample_save_brstack() to capture branch records for perf_sample_data - Added comment explaining rationale for setting BRBCR_EL1_FZP for user only traces - Dropped BRBE prohibited state mechanism while in armv8pmu_branch_read() - Implemented event task context based branch records save mechanism Changes in V8: https://lore.kernel.org/all/20230123125956.1350336-1-anshuman.khandual@arm.com/ - Replaced arm_pmu->features as arm_pmu->has_branch_stack, updated its helper - Added a comment and line break before arm_pmu->private element - Added WARN_ON_ONCE() in helpers i.e armv8pmu_branch_[read|valid|enable|disable]() - Dropped comments in armv8pmu_enable_event() and armv8pmu_disable_event() - Replaced open bank encoding in BRBFCR_EL1 with SYS_FIELD_PREP() - Changed brbe_hw_attr->brbe_version from 'bool' to 'int' - Updated pr_warn() as pr_warn_once() with values in brbe_get_perf_[type|priv]() - Replaced all pr_warn_once() as pr_debug_once() in armv8pmu_branch_valid() - Added a comment in branch_type_to_brbcr() for the BRBCR_EL1 privilege settings - Modified the comment related to BRBINFx_EL1.LASTFAILED in capture_brbe_flags() - Modified brbe_get_perf_entry_type() as brbe_set_perf_entry_type() - Renamed brbe_valid() as brbe_record_is_complete() - Renamed brbe_source() as brbe_record_is_source_only() - Renamed brbe_target() as brbe_record_is_target_only() - Inverted checks for !brbe_record_is_[target|source]_only() for info capture - Replaced 'fetch' with 'get' in all helpers that extract field value - Dropped 'static int brbe_current_bank' optimization in select_brbe_bank() - Dropped select_brbe_bank_index() completely, added capture_branch_entry() - Process captured branch entries in two separate loops one for each BRBE bank - Moved branch_records_alloc() inside armv8pmu_probe_pmu() - Added a forward declaration for the helper has_branch_stack() - Added new callbacks armv8pmu_private_alloc() and armv8pmu_private_free() - Updated armv8pmu_probe_pmu() to allocate the private structure before SMP call Changes in V7: https://lore.kernel.org/all/20230105031039.207972-1-anshuman.khandual@arm.com/ - Folded [PATCH 7/7] into [PATCH 3/7] which enables branch stack sampling event - Defined BRBFCR_EL1_BRANCH_FILTERS, BRBCR_EL1_DEFAULT_CONFIG in the header - Defined BRBFCR_EL1_DEFAULT_CONFIG in the header - Updated BRBCR_EL1_DEFAULT_CONFIG with BRBCR_EL1_FZP - Defined BRBCR_EL1_DEFAULT_TS in the header - Updated BRBCR_EL1_DEFAULT_CONFIG with BRBCR_EL1_DEFAULT_TS - Moved BRBCR_EL1_DEFAULT_CONFIG check inside branch_type_to_brbcr() - Moved down BRBCR_EL1_CC, BRBCR_EL1_MPRED later in branch_type_to_brbcr() - Also set BRBE in paused state in armv8pmu_branch_disable() - Dropped brbe_paused(), set_brbe_paused() helpers - Extracted error string via branch_filter_error_msg[] for armv8pmu_branch_valid() - Replaced brbe_v1p1 with brbe_version in struct brbe_hw_attr - Added valid_brbe_[cc, format, version]() helpers - Split a separate brbe_attributes_probe() from armv8pmu_branch_probe() - Capture event->attr.branch_sample_type earlier in armv8pmu_branch_valid() - Defined enum brbe_bank_idx with possible values for BRBE bank indices - Changed armpmu->hw_attr into armpmu->private - Added missing space in stub definition for armv8pmu_branch_valid() - Replaced both kmalloc() with kzalloc() - Added BRBE_BANK_MAX_ENTRIES - Updated comment for capture_brbe_flags() - Updated comment for struct brbe_hw_attr - Dropped space after type cast in couple of places - Replaced inverse with negation for testing BRBCR_EL1_FZP in armv8pmu_branch_read() - Captured cpuc->branches->branch_entries[idx] in a local variable - Dropped saved_priv from armv8pmu_branch_read() - Reorganize PERF_SAMPLE_BRANCH_NO_[CYCLES|NO_FLAGS] related configuration - Replaced with FIELD_GET() and FIELD_PREP() wherever applicable - Replaced BRBCR_EL1_TS_PHYSICAL with BRBCR_EL1_TS_VIRTUAL - Moved valid_brbe_nr(), valid_brbe_cc(), valid_brbe_format(), valid_brbe_version() select_brbe_bank(), select_brbe_bank_index() helpers inside the C implementation - Reorganized brbe_valid_nr() and dropped the pr_warn() message - Changed probe sequence in brbe_attributes_probe() - Added 'brbcr' argument into capture_brbe_flags() to ascertain correct state - Disable BRBE before disabling the PMU event counter - Enable PERF_SAMPLE_BRANCH_HV filters when is_kernel_in_hyp_mode() - Guard armv8pmu_reset() & armv8pmu_sched_task() with arm_pmu_branch_stack_supported() Changes in V6: https://lore.kernel.org/linux-arm-kernel/20221208084402.863310-1-anshuman.khandual@arm.com/ - Restore the exception level privilege after reading the branch records - Unpause the buffer after reading the branch records - Decouple BRBCR_EL1_EXCEPTION/ERTN from perf event privilege level - Reworked BRBE implementation and branch stack sampling support on arm pmu - BRBE implementation is now part of overall ARMV8 PMU implementation - BRBE implementation moved from drivers/perf/ to inside arch/arm64/kernel/ - CONFIG_ARM_BRBE_PMU renamed as CONFIG_ARM64_BRBE in arch/arm64/Kconfig - File moved - drivers/perf/arm_pmu_brbe.c -> arch/arm64/kernel/brbe.c - File moved - drivers/perf/arm_pmu_brbe.h -> arch/arm64/kernel/brbe.h - BRBE name has been dropped from struct arm_pmu and struct hw_pmu_events - BRBE name has been abstracted out as 'branches' in arm_pmu and hw_pmu_events - BRBE name has been abstracted out as 'branches' in ARMV8 PMU implementation - Added sched_task() callback into struct arm_pmu - Added 'hw_attr' into struct arm_pmu encapsulating possible PMU HW attributes - Dropped explicit attributes brbe_(v1p1, nr, cc, format) from struct arm_pmu - Dropped brbfcr, brbcr, registers scratch area from struct hw_pmu_events - Dropped brbe_users, brbe_context tracking in struct hw_pmu_events - Added 'features' tracking into struct arm_pmu with ARM_PMU_BRANCH_STACK flag - armpmu->hw_attr maps into 'struct brbe_hw_attr' inside BRBE implementation - Set ARM_PMU_BRANCH_STACK in 'arm_pmu->features' after successful BRBE probe - Added armv8pmu_branch_reset() inside armv8pmu_branch_enable() - Dropped brbe_supported() as events will be rejected via ARM_PMU_BRANCH_STACK - Dropped set_brbe_disabled() as well - Reformated armv8pmu_branch_valid() warnings while rejecting unsupported events Changes in V5: https://lore.kernel.org/linux-arm-kernel/20221107062514.2851047-1-anshuman.khandual@arm.com/ - Changed BRBCR_EL1.VIRTUAL from 0b1 to 0b01 - Changed BRBFCR_EL1.EnL into BRBFCR_EL1.EnI - Changed config ARM_BRBE_PMU from 'tristate' to 'bool' Changes in V4: https://lore.kernel.org/all/20221017055713.451092-1-anshuman.khandual@arm.com/ - Changed ../tools/sysreg declarations as suggested - Set PERF_SAMPLE_BRANCH_STACK in data.sample_flags - Dropped perfmon_capable() check in armpmu_event_init() - s/pr_warn_once/pr_info in armpmu_event_init() - Added brbe_format element into struct pmu_hw_events - Changed v1p1 as brbe_v1p1 in struct pmu_hw_events - Dropped pr_info() from arm64_pmu_brbe_probe(), solved LOCKDEP warning Changes in V3: https://lore.kernel.org/all/20220929075857.158358-1-anshuman.khandual@arm.com/ - Moved brbe_stack from the stack and now dynamically allocated - Return PERF_BR_PRIV_UNKNOWN instead of -1 in brbe_fetch_perf_priv() - Moved BRBIDR0, BRBCR, BRBFCR registers and fields into tools/sysreg - Created dummy BRBINF_EL1 field definitions in tools/sysreg - Dropped ARMPMU_EVT_PRIV framework which cached perfmon_capable() - Both exception and exception return branche records are now captured only if the event has PERF_SAMPLE_BRANCH_KERNEL which would already been checked in generic perf via perf_allow_kernel() Changes in V2: https://lore.kernel.org/all/20220908051046.465307-1-anshuman.khandual@arm.com/ - Dropped branch sample filter helpers consolidation patch from this series - Added new hw_perf_event.flags element ARMPMU_EVT_PRIV to cache perfmon_capable() - Use cached perfmon_capable() while configuring BRBE branch record filters Changes in V1: https://lore.kernel.org/linux-arm-kernel/20220613100119.684673-1-anshuman.khandual@arm.com/ - Added CONFIG_PERF_EVENTS wrapper for all branch sample filter helpers - Process new perf branch types via PERF_BR_EXTEND_ABI Changes in RFC V2: https://lore.kernel.org/linux-arm-kernel/20220412115455.293119-1-anshuman.khandual@arm.com/ - Added branch_sample_priv() while consolidating other branch sample filter helpers - Changed all SYS_BRBXXXN_EL1 register definition encodings per Marc - Changed the BRBE driver as per proposed BRBE related perf ABI changes (V5) - Added documentation for struct arm_pmu changes, updated commit message - Updated commit message for BRBE detection infrastructure patch - PERF_SAMPLE_BRANCH_KERNEL gets checked during arm event init (outside the driver) - Branch privilege state capture mechanism has now moved inside the driver Changes in RFC V1: https://lore.kernel.org/all/1642998653-21377-1-git-send-email-anshuman.khandual@arm.com/ Cc: Catalin Marinas Cc: Will Deacon Cc: Mark Rutland Cc: Mark Brown Cc: James Clark Cc: Rob Herring Cc: Marc Zyngier Cc: Suzuki Poulose Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Cc: linux-kernel@vger.kernel.org Anshuman Khandual (10): drivers: perf: arm_pmu: Add new sched_task() callback arm64/perf: Add BRBE registers and fields arm64/perf: Add branch stack support in struct arm_pmu arm64/perf: Add branch stack support in struct pmu_hw_events arm64/perf: Add branch stack support in ARMV8 PMU arm64/perf: Enable branch stack events via FEAT_BRBE arm64/perf: Add PERF_ATTACH_TASK_DATA to events with has_branch_stack() arm64/perf: Add struct brbe_regset helper functions arm64/perf: Implement branch records save on task sched out arm64/perf: Implement branch records save on PMU IRQ arch/arm64/Kconfig | 11 + arch/arm64/include/asm/perf_event.h | 46 ++ arch/arm64/include/asm/sysreg.h | 103 ++++ arch/arm64/kernel/Makefile | 1 + arch/arm64/kernel/brbe.c | 758 ++++++++++++++++++++++++++++ arch/arm64/kernel/brbe.h | 270 ++++++++++ arch/arm64/kernel/perf_event.c | 106 +++- arch/arm64/tools/sysreg | 159 ++++++ drivers/perf/arm_pmu.c | 12 +- include/linux/perf/arm_pmu.h | 22 +- 10 files changed, 1462 insertions(+), 26 deletions(-) create mode 100644 arch/arm64/kernel/brbe.c create mode 100644 arch/arm64/kernel/brbe.h -- 2.25.1