kernel/linux.git/drivers/perf/arm_pmuv3.c, branch linux-7.1.y

Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

2025-12-03T01:03:55+00:00

Pull arm64 updates from Catalin Marinas: "These are the arm64 updates for 6.19. The biggest part is the Arm MPAM driver under drivers/resctrl/. There's a patch touching mm/ to handle spurious faults for huge pmd (similar to the pte version). The corresponding arm64 part allows us to avoid the TLB maintenance if a (huge) page is reused after a write fault. There's EFI refactoring to allow runtime services with preemption enabled and the rest is the usual perf/PMU updates and several cleanups/typos. Summary: Core features: - Basic Arm MPAM (Memory system resource Partitioning And Monitoring) driver under drivers/resctrl/ which makes use of the fs/rectrl/ API Perf and PMU: - Avoid cycle counter on multi-threaded CPUs - Extend CSPMU device probing and add additional filtering support for NVIDIA implementations - Add support for the PMUs on the NoC S3 interconnect - Add additional compatible strings for new Cortex and C1 CPUs - Add support for data source filtering to the SPE driver - Add support for i.MX8QM and "DB" PMU in the imx PMU driver Memory managemennt: - Avoid broadcast TLBI if page reused in write fault - Elide TLB invalidation if the old PTE was not valid - Drop redundant cpu_set_*_tcr_t0sz() macros - Propagate pgtable_alloc() errors outside of __create_pgd_mapping() - Propagate return value from __change_memory_common() ACPI and EFI: - Call EFI runtime services without disabling preemption - Remove unused ACPI function Miscellaneous: - ptrace support to disable streaming on SME-only systems - Improve sysreg generation to include a 'Prefix' descriptor - Replace __ASSEMBLY__ with __ASSEMBLER__ - Align register dumps in the kselftest zt-test - Remove some no longer used macros/functions - Various spelling corrections" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (94 commits) arm64/mm: Document why linear map split failure upon vm_reset_perms is not problematic arm64/pageattr: Propagate return value from __change_memory_common arm64/sysreg: Remove unused define ARM64_FEATURE_FIELD_BITS KVM: arm64: selftests: Consider all 7 possible levels of cache KVM: arm64: selftests: Remove ARM64_FEATURE_FIELD_BITS and its last user arm64: atomics: lse: Remove unused parameters from ATOMIC_FETCH_OP_AND macros Documentation/arm64: Fix the typo of register names ACPI: GTDT: Get rid of acpi_arch_timer_mem_init() perf: arm_spe: Add support for filtering on data source perf: Add perf_event_attr::config4 perf/imx_ddr: Add support for PMU in DB (system interconnects) perf/imx_ddr: Get and enable optional clks perf/imx_ddr: Move ida_alloc() from ddr_perf_init() to ddr_perf_probe() dt-bindings: perf: fsl-imx-ddr: Add compatible string for i.MX8QM, i.MX8QXP and i.MX8DXL arm64: remove duplicate ARCH_HAS_MEM_ENCRYPT arm64: mm: use untagged address to calculate page index MAINTAINERS: new entry for MPAM Driver arm_mpam: Add kunit tests for props_mismatch() arm_mpam: Add kunit test for bitmap reset arm_mpam: Add helper to reset saved mbwu state ...

perf: arm_pmuv3: Add new Cortex and C1 CPU PMUs

2025-11-03T14:21:55+00:00

Add CPU PMU compatible strings for Cortex-A320, Cortex-A520AE, Cortex-A720AE, and C1 Nano/Premium/Pro/Ultra. Signed-off-by: Rob Herring (Arm) Signed-off-by: Will Deacon

perf: arm_pmuv3: Don't use PMCCNTR_EL0 on SMT cores

2025-11-03T13:28:48+00:00

CPU_CYCLES is expected to count the logical CPU (PE) clock. Currently it's preferred to use PMCCNTR_EL0 for counting CPU_CYCLES, but it'll count processor clock rather than the PE clock (ARM DDI0487 L.b D13.1.3) if one of the SMT siblings is not idle on a multi-threaded implementation. So don't use it on SMT cores. Introduce topology_core_has_smt() for knowing the SMT implementation and cached it in arm_pmu::has_smt during allocation. When counting cycles on SMT CPU 2-3 and CPU 3 is idle, without this patch we'll get: [root@client1 tmp]# perf stat -e cycles -A -C 2-3 -- stress-ng -c 1 --taskset 2 --timeout 1 [...] Performance counter stats for 'CPU(s) 2-3': CPU2 2880457316 cycles CPU3 2880459810 cycles 1.254688470 seconds time elapsed With this patch the idle state of CPU3 is observed as expected: [root@client1 ~]# perf stat -e cycles -A -C 2-3 -- stress-ng -c 1 --taskset 2 --timeout 1 [...] Performance counter stats for 'CPU(s) 2-3': CPU2 2558580492 cycles CPU3 305749 cycles 1.113626410 seconds time elapsed Signed-off-by: Yicong Yang Signed-off-by: Will Deacon

perf: arm_pmu: Kill last use of per-CPU cpu_armpmu pointer

2025-10-27T16:16:37+00:00

Having removed the use of the cpu_armpmu per-CPU variable from the interrupt handling, the only user left is the BRBE scheduler hook. It is easy to drop the use of this variable by following the pointer to the generic PMU structure, and get the arm_pmu structure from there. Perform the conversion and kill cpu_armpmu altogether. Suggested-by: Will Deacon Signed-off-by: Marc Zyngier Signed-off-by: Thomas Gleixner Tested-by: Will Deacon Link: https://patch.msgid.link/20251020122944.3074811-27-maz@kernel.org

perf: arm_pmuv3: Factor out PMCCNTR_EL0 use conditions

2025-09-18T13:35:54+00:00

PMCCNTR_EL0 is preferred for counting CPU_CYCLES under certain conditions. Factor out the condition check to a separate function for further extension. Add documents for better understanding. No functional changes intended. Reviewed-by: James Clark Acked-by: Mark Rutland Signed-off-by: Yicong Yang Signed-off-by: Will Deacon

perf: arm_pmuv3: Add support for the Branch Record Buffer Extension (BRBE)

2025-07-08T16:58:49+00:00

The ARMv9.2 architecture introduces the optional Branch Record Buffer Extension (BRBE), which records information about branches as they are executed into set of branch record registers. BRBE is similar to x86's Last Branch Record (LBR) and PowerPC's Branch History Rolling Buffer (BHRB). BRBE supports filtering by exception level and can filter just the source or target address if excluded to avoid leaking privileged addresses. The h/w filter would be sufficient except when there are multiple events with disjoint filtering requirements. In this case, BRBE is configured with a union of all the events' desired branches, and then the recorded branches are filtered based on each event's filter. For example, with one event capturing kernel events and another event capturing user events, BRBE will be configured to capture both kernel and user branches. When handling event overflow, the branch records have to be filtered by software to only include kernel or user branch addresses for that event. In contrast, x86 simply configures LBR using the last installed event which seems broken. It is possible on x86 to configure branch filter such that no branches are ever recorded (e.g. -j save_type). For BRBE, events with a configuration that will result in no samples are rejected. Recording branches in KVM guests is not supported like x86. However, perf on x86 allows requesting branch recording in guests. The guest events are recorded, but the resulting branches are all from the host. For BRBE, events with branch recording and "exclude_host" set are rejected. Requiring "exclude_guest" to be set did not work. The default for the perf tool does set "exclude_guest" if no exception level options are specified. However, specifying kernel or user events defaults to including both host and guest. In this case, only host branches are recorded. BRBE can support some additional exception branch types compared to x86. On x86, all exceptions other than syscalls are recorded as IRQ. With BRBE, it is possible to better categorize these exceptions. One limitation relative to x86 is we cannot distinguish a syscall return from other exception returns. So all exception returns are recorded as ERET type. The FIQ branch type is omitted as the only FIQ user is Apple platforms which don't support BRBE. The debug branch types are omitted as there is no clear need for them. BRBE records are invalidated whenever events are reconfigured, a new task is scheduled in, or after recording is paused (and the records have been recorded for the event). The architecture allows branch records to be invalidated by the PE under implementation defined conditions. It is expected that these conditions are rare. Cc: Catalin Marinas Co-developed-by: Anshuman Khandual Signed-off-by: Anshuman Khandual Co-developed-by: Mark Rutland Signed-off-by: Mark Rutland Tested-by: James Clark Signed-off-by: Rob Herring (Arm) tested-by: Adam Young Acked-by: Mark Rutland Link: https://lore.kernel.org/r/20250611-arm-brbe-v19-v23-4-e7775563036e@kernel.org [will: Fix sparse warnings about mixed declarations and code. Fix C99 comment syntax.] Signed-off-by: Will Deacon

perf/arm: Remove driver-specific throttle support

2025-05-21T11:57:44+00:00

The throttle support has been added in the generic code. Remove the driver-specific throttle support. Besides the throttle, perf_event_overflow may return true because of event_limit. It already does an inatomic event disable. The pmu->stop is not required either. Signed-off-by: Kan Liang Signed-off-by: Peter Zijlstra (Intel) Tested-by: Leo Yan Link: https://lore.kernel.org/r/20250520181644.2673067-9-kan.liang@linux.intel.com

perf: arm_pmuv3: Don't disable counter in armv8pmu_enable_event()

2025-03-01T05:08:10+00:00

Currently armv8pmu_enable_event() starts by disabling the event counter it has been asked to enable. This should not be necessary as the counter (and the PMU as a whole) should not be active when armv8pmu_enable_event() is called. Remove the redundant call to armv8pmu_disable_event_counter(). At the same time, remove the comment immeditately above as everything it says is obvious from the function names below. Signed-off-by: Mark Rutland Signed-off-by: Rob Herring (Arm) Reviewed-by: Anshuman Khandual Tested-by: James Clark Link: https://lore.kernel.org/r/20250218-arm-brbe-v19-v20-3-4e9922fc2e8e@kernel.org Signed-off-by: Will Deacon

perf: arm_pmuv3: Call kvm_vcpu_pmu_resync_el0() before enabling counters

2025-03-01T05:08:10+00:00

Counting events related to setup of the PMU is not desired, but kvm_vcpu_pmu_resync_el0() is called just after the PMU counters have been enabled. Move the call to before enabling the counters. Signed-off-by: Rob Herring (Arm) Reviewed-by: Anshuman Khandual Tested-by: James Clark Link: https://lore.kernel.org/r/20250218-arm-brbe-v19-v20-1-4e9922fc2e8e@kernel.org Signed-off-by: Will Deacon

perf: arm_pmuv3: Add support for ARM Rainier PMU

2025-02-28T01:31:21+00:00

Add support for the ARM Rainier CPU core PMU. Signed-off-by: Vincenzo Frascino Reviewed-by: Linus Walleij Link: https://lore.kernel.org/r/20250221180349.1413089-7-vincenzo.frascino@arm.com Signed-off-by: Will Deacon