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2024-04-26drivers/perf: riscv: Implement SBI PMU snapshot functionAtish Patra1-0/+8
SBI v2.0 SBI introduced PMU snapshot feature which adds the following features. 1. Read counter values directly from the shared memory instead of csr read. 2. Start multiple counters with initial values with one SBI call. These functionalities optimizes the number of traps to the higher privilege mode. If the kernel is in VS mode while the hypervisor deploy trap & emulate method, this would minimize all the hpmcounter CSR read traps. If the kernel is running in S-mode, the benefits reduced to CSR latency vs DRAM/cache latency as there is no trap involved while accessing the hpmcounter CSRs. In both modes, it does saves the number of ecalls while starting multiple counter together with an initial values. This is a likely scenario if multiple counters overflow at the same time. Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Samuel Holland <samuel.holland@sifive.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Link: https://lore.kernel.org/r/20240420151741.962500-10-atishp@rivosinc.com Signed-off-by: Anup Patel <anup@brainfault.org>
2023-08-16riscv: Prepare for user-space perf event mmap supportAlexandre Ghiti1-0/+4
Provide all the necessary bits in the generic riscv pmu driver to be able to mmap perf events in userspace: the heavy lifting lies in the driver backend, namely the legacy and sbi implementations. Note that arch_perf_update_userpage is almost a copy of arm64 code. Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com>
2023-08-16drivers: perf: Rename riscv pmu sbi driverAlexandre Ghiti1-1/+1
That's just cosmetic, no functional changes. Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com>
2023-08-16include: riscv: Fix wrong include guard in riscv_pmu.hAlexandre Ghiti1-3/+3
The current include guard prevents the inclusion of asm/perf_event.h which uses the same include guard: fix the one in riscv_pmu.h so that it matches the file name. Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com>
2023-02-07perf: RISC-V: Improve privilege mode filtering for perfAtish Patra1-0/+2
Currently, the host driver doesn't have any method to identify if the requested perf event is from kvm or bare metal. As KVM runs in HS mode, there are no separate hypervisor privilege mode to distinguish between the attributes for guest/host. Improve the privilege mode filtering by using the event specific config1 field. Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2023-02-07perf: RISC-V: Define helper functions expose hpm counter width and countAtish Patra1-0/+3
KVM module needs to know how many hardware counters and the counter width that the platform supports. Otherwise, it will not be able to show optimal value of virtual counters to the guest. The virtual hardware counters also need to have the same width as the logical hardware counters for simplicity. However, there shouldn't be mapping between virtual hardware counters and logical hardware counters. As we don't support hetergeneous harts or counters with different width as of now, the implementation relies on the counter width of the first available programmable counter. Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-09-08perf: RISC-V: exclude invalid pmu counters from SBI callsSergey Matyukevich1-1/+1
SBI firmware may not provide information for some counters in response to SBI_EXT_PMU_COUNTER_GET_INFO call. Exclude such counters from the subsequent SBI requests. For this purpose use global mask to keep track of fully specified counters. Signed-off-by: Sergey Matyukevich <sergey.matyukevich@syntacore.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Link: https://lore.kernel.org/r/20220830155306.301714-3-geomatsi@gmail.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-07-06drivers/perf: riscv_pmu: Add riscv pmu pm notifierEric Lin1-0/+4
Currently, when the CPU is doing suspend to ram, we don't save pmu counter register and its content will be lost. To ensure perf profiling is not affected by suspend to ram, this patch is based on arm_pmu CPU_PM notifier and implements riscv pmu pm notifier. In the pm notifier, we stop the counter and update the counter value before suspend and start the counter after resume. Signed-off-by: Eric Lin <eric.lin@sifive.com> Link: https://lore.kernel.org/r/20220705091920.27432-1-eric.lin@sifive.com Signed-off-by: Will Deacon <will@kernel.org>
2022-03-21RISC-V: Add sscofpmf extension supportAtish Patra1-0/+2
The sscofpmf extension allows counter overflow and filtering for programmable counters. Enable the perf driver to handle the overflow interrupt. The overflow interrupt is a hart local interrupt. Thus, per cpu overflow interrupts are setup as a child under the root INTC irq domain. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-03-21RISC-V: Add perf platform driver based on SBI PMU extensionAtish Patra1-2/+4
RISC-V SBI specification added a PMU extension that allows to configure start/stop any pmu counter. The RISC-V perf can use most of the generic perf features except interrupt overflow and event filtering based on privilege mode which will be added in future. It also allows to monitor a handful of firmware counters that can provide insights into firmware activity during a performance analysis. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-03-21RISC-V: Add a simple platform driver for RISC-V legacy perfAtish Patra1-0/+6
The old RISC-V perf implementation allowed counting of only cycle/instruction counters using perf. Restore that feature by implementing a simple platform driver under a separate config to provide backward compatibility. Any existing software stack will continue to work as it is. However, it provides an easy way out in future where we can remove the legacy driver. Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-03-21RISC-V: Add a perf core library for pmu driversAtish Patra1-0/+65
Implement a perf core library that can support all the essential perf features in future. It can also accommodate any type of PMU implementation in future. Currently, both SBI based perf driver and legacy driver implemented uses the library. Most of the common perf functionalities are kept in this core library wile PMU specific driver can implement PMU specific features. For example, the SBI specific functionality will be implemented in the SBI specific driver. Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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