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diff --git a/Documentation/devicetree/bindings/perf/riscv,pmu.yaml b/Documentation/devicetree/bindings/perf/riscv,pmu.yaml new file mode 100644 index 000000000000..d01c677ad3c7 --- /dev/null +++ b/Documentation/devicetree/bindings/perf/riscv,pmu.yaml @@ -0,0 +1,160 @@ +# SPDX-License-Identifier: BSD-2-Clause +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/perf/riscv,pmu.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: RISC-V SBI PMU events + +maintainers: + - Atish Patra <atishp@rivosinc.com> + +description: | + The SBI PMU extension allows supervisor software to configure, start and + stop any performance counter at anytime. Thus, a user can leverage all + capabilities of performance analysis tools, such as perf, if the SBI PMU + extension is enabled. The following constraints apply: + + The platform must provide information about PMU event to counter mappings + either via device tree or another way, specific to the platform. + Without the event to counter mappings, the SBI PMU extension cannot be used. + + Platforms should provide information about the PMU event selector values + that should be encoded in the expected value of MHPMEVENTx while configuring + MHPMCOUNTERx for that specific event. The can either be done via device tree + or another way, specific to the platform. + The exact value to be written to MHPMEVENTx is completely dependent on the + platform. + + For information on the SBI specification see the section "Performance + Monitoring Unit Extension" of: + https://github.com/riscv-non-isa/riscv-sbi-doc/blob/master/riscv-sbi.adoc + +properties: + compatible: + const: riscv,pmu + + riscv,event-to-mhpmevent: + $ref: /schemas/types.yaml#/definitions/uint32-matrix + description: + Represents an ONE-to-ONE mapping between a PMU event and the event + selector value that the platform expects to be written to the MHPMEVENTx + CSR for that event. + The mapping is encoded in an matrix format where each element represents + an event. + This property shouldn't encode any raw hardware event. + items: + items: + - description: event_idx, a 20-bit wide encoding of the event type and + code. Refer to the SBI specification for a complete description of + the event types and codes. + - description: upper 32 bits of the event selector value for MHPMEVENTx + - description: lower 32 bits of the event selector value for MHPMEVENTx + + riscv,event-to-mhpmcounters: + $ref: /schemas/types.yaml#/definitions/uint32-matrix + description: + Represents a MANY-to-MANY mapping between a range of events and all the + MHPMCOUNTERx in a bitmap format that can be used to monitor these range + of events. The information is encoded in an matrix format where each + element represents a certain range of events and corresponding counters. + This property shouldn't encode any raw event. + items: + items: + - description: first event_idx of the range of events + - description: last event_idx of the range of events + - description: bitmap of MHPMCOUNTERx for this event + + riscv,raw-event-to-mhpmcounters: + $ref: /schemas/types.yaml#/definitions/uint32-matrix + description: + Represents an ONE-to-MANY or MANY-to-MANY mapping between the rawevent(s) + and all the MHPMCOUNTERx in a bitmap format that can be used to monitor + that raw event. + The encoding of the raw events are platform specific. The information is + encoded in a matrix format where each element represents the specific raw + event(s). + If a platform directly encodes each raw PMU event as a unique ID, the + value of variant must be 0xffffffff_ffffffff. + items: + items: + - description: + upper 32 invariant bits for the range of events + - description: + lower 32 invariant bits for the range of events + - description: + upper 32 bits of the variant bit mask for the range of events + - description: + lower 32 bits of the variant bit mask for the range of events + - description: + bitmap of all MHPMCOUNTERx that can monitor the range of events + +dependencies: + riscv,event-to-mhpmevent: [ "riscv,event-to-mhpmcounters" ] + +required: + - compatible + +additionalProperties: false + +examples: + - | + pmu { + compatible = "riscv,pmu"; + riscv,event-to-mhpmevent = <0x0000B 0x0000 0x0001>; + riscv,event-to-mhpmcounters = <0x00001 0x00001 0x00000001>, + <0x00002 0x00002 0x00000004>, + <0x00003 0x0000A 0x00000ff8>, + <0x10000 0x10033 0x000ff000>; + riscv,raw-event-to-mhpmcounters = + /* For event ID 0x0002 */ + <0x0000 0x0002 0xffffffff 0xffffffff 0x00000f8>, + /* For event ID 0-4 */ + <0x0 0x0 0xffffffff 0xfffffff0 0x00000ff0>, + /* For event ID 0xffffffff0000000f - 0xffffffff000000ff */ + <0xffffffff 0x0 0xffffffff 0xffffff0f 0x00000ff0>; + }; + + - | + /* + * For HiFive Unmatched board the encodings can be found here + * https://sifive.cdn.prismic.io/sifive/1a82e600-1f93-4f41-b2d8-86ed8b16acba_fu740-c000-manual-v1p6.pdf + * + * This example also binds standard SBI PMU hardware IDs to U74 PMU event + * codes, U74 uses a bitfield for events encoding, so several U74 events + * can be bound to a single perf ID. + * See SBI PMU hardware IDs in arch/riscv/include/asm/sbi.h + */ + pmu { + compatible = "riscv,pmu"; + riscv,event-to-mhpmevent = + /* SBI_PMU_HW_CACHE_REFERENCES -> Instruction or Data cache/ITIM busy */ + <0x00003 0x00000000 0x1801>, + /* SBI_PMU_HW_CACHE_MISSES -> Instruction or Data cache miss or MMIO access */ + <0x00004 0x00000000 0x0302>, + /* SBI_PMU_HW_BRANCH_INSTRUCTIONS -> Conditional branch retired */ + <0x00005 0x00000000 0x4000>, + /* SBI_PMU_HW_BRANCH_MISSES -> Branch or jump misprediction */ + <0x00006 0x00000000 0x6001>, + /* L1D_READ_MISS -> Data cache miss or MMIO access */ + <0x10001 0x00000000 0x0202>, + /* L1D_WRITE_ACCESS -> Data cache write-back */ + <0x10002 0x00000000 0x0402>, + /* L1I_READ_ACCESS -> Instruction cache miss */ + <0x10009 0x00000000 0x0102>, + /* LL_READ_MISS -> UTLB miss */ + <0x10011 0x00000000 0x2002>, + /* DTLB_READ_MISS -> Data TLB miss */ + <0x10019 0x00000000 0x1002>, + /* ITLB_READ_MISS-> Instruction TLB miss */ + <0x10021 0x00000000 0x0802>; + riscv,event-to-mhpmcounters = <0x00003 0x00006 0x18>, + <0x10001 0x10002 0x18>, + <0x10009 0x10009 0x18>, + <0x10011 0x10011 0x18>, + <0x10019 0x10019 0x18>, + <0x10021 0x10021 0x18>; + riscv,raw-event-to-mhpmcounters = <0x0 0x0 0xffffffff 0xfc0000ff 0x18>, + <0x0 0x1 0xffffffff 0xfff800ff 0x18>, + <0x0 0x2 0xffffffff 0xffffe0ff 0x18>; + }; |