[PATCH RFC v7 1/9] firmware: arm_scmi: Add QCOM Generic Vendor Protocol documentation
Pragnesh Papaniya <[email protected]>
| Newsgroups | org.kernel.vger.arm-scmi,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-arm-msm,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-kernel,org.kernel.vger.linux-pm,org.kernel.vger.linux-tegra |
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From: Sibi Sankar <[email protected]> Add QCOM System Control Management Interface (SCMI) Generic Vendor Extensions Protocol documentation. It exposes Qualcomm SoC-specific features through (algorithm string, param_id) pairs carried over a small set of generic SET/GET/START/STOP commands, alongside the standard PROTOCOL_VERSION / _ATTRIBUTES / _MESSAGE_ATTRIBUTES handshake required by the Arm SCMI specification. Document the protocol so that drivers targeting it have a stable reference for command ids, payload layouts and status code semantics. The first algorithm covered is MEMLAT (memory latency governor), including its memory-group model (DDR, LLCC, DDR_QOS), event-map programming and per- monitor frequency voting tables. Signed-off-by: Sibi Sankar <[email protected]> Co-developed-by: Pragnesh Papaniya <[email protected]> Signed-off-by: Pragnesh Papaniya <[email protected]> --- .../arm_scmi/vendors/qcom/qcom_generic.rst | 647 +++++++++++++++++++++ 1 file changed, 647 insertions(+) diff --git a/drivers/firmware/arm_scmi/vendors/qcom/qcom_generic.rst b/drivers/firmware/arm_scmi/vendors/qcom/qcom_generic.rst new file mode 100644 index 000000000000..ba0c64729790 --- /dev/null +++ b/drivers/firmware/arm_scmi/vendors/qcom/qcom_generic.rst @@ -0,0 +1,647 @@ +.. SPDX-License-Identifier: GPL-2.0 +.. include:: <isonum.txt> + +=============================================================================== +QCOM System Control and Management Interface(SCMI) Vendor Protocols Extension +=============================================================================== + +:Copyright: |copy| Qualcomm Technologies, Inc. and/or its subsidiaries. + +:Author: + - Sibi Sankar <[email protected]> + - Pragnesh Papaniya <[email protected]> + +SCMI_GENERIC: System Control and Management Interface QCOM Generic Vendor Protocol +================================================================================== + +This protocol is intended as a generic way of exposing a number of Qualcomm +SoC specific features through a mixture of pre-determined algorithm string and +param_id pairs hosted on the SCMI controller. It implements an interface compliant +with the Arm SCMI Specification with additional vendor specific commands as +detailed below. + +Supported algorithm strings are documented in their own sections after the +generic commands (currently: MEMLAT, see below). + +Commands: +_________ + +PROTOCOL_VERSION +~~~~~~~~~~~~~~~~ + +message_id: 0x0 +protocol_id: 0x80 + ++---------------+--------------------------------------------------------------+ +|Return values | ++---------------+--------------------------------------------------------------+ +|Name |Description | ++---------------+--------------------------------------------------------------+ +|int32 status |See ARM SCMI Specification for status code definitions. | ++---------------+--------------------------------------------------------------+ +|uint32 version |For this revision of the specification, this value must be | +| |0x10000. | ++---------------+--------------------------------------------------------------+ + +PROTOCOL_ATTRIBUTES +~~~~~~~~~~~~~~~~~~~ + +message_id: 0x1 +protocol_id: 0x80 + ++------------------+-----------------------------------------------------------+ +|Return values | ++------------------+-----------------------------------------------------------+ +|Name |Description | ++------------------+-----------------------------------------------------------+ +|int32 status |See ARM SCMI Specification for status code definitions. | ++------------------+-----------------------------------------------------------+ +|uint32 attributes |Bits[31:16] Reserved, must be set to 0. | +| |Bits[15:8] Number of agents in the system. Must match the | +| |value reported by the standard BASE protocol's | +| |PROTOCOL_ATTRIBUTES response. | +| |Bits[7:0] Number of algorithmic strings supported by the | +| |system. Only "MEMLAT" is currently supported hence it | +| |returns 1. | ++------------------+-----------------------------------------------------------+ + +PROTOCOL_MESSAGE_ATTRIBUTES +~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +message_id: 0x2 +protocol_id: 0x80 + ++------------------+-----------------------------------------------------------+ +|Return values | ++------------------+-----------------------------------------------------------+ +|Name |Description | ++------------------+-----------------------------------------------------------+ +|int32 status |See ARM SCMI Specification for status code definitions. | ++------------------+-----------------------------------------------------------+ +|uint32 attributes |For all message IDs the parameter has a value of 0. | ++------------------+-----------------------------------------------------------+ + +QCOM_SCMI_SET_PARAM +~~~~~~~~~~~~~~~~~~~ + +message_id: 0x10 +protocol_id: 0x80 + ++------------------+-----------------------------------------------------------+ +|Parameters | ++------------------+-----------------------------------------------------------+ +|Name |Description | ++------------------+-----------------------------------------------------------+ +|uint32 ext_id |Reserved, must be zero. | ++------------------+-----------------------------------------------------------+ +|uint32 algo_low |Lower 32-bit value of the algorithm string. | ++------------------+-----------------------------------------------------------+ +|uint32 algo_high |Upper 32-bit value of the algorithm string. | ++------------------+-----------------------------------------------------------+ +|uint32 param_id |Serves as the token message id for the algorithm string | +| |and is used to set various parameters supported by it. | ++------------------+-----------------------------------------------------------+ +|uint32 buf[] |Serves as the payload for the specified param_id and | +| |algorithm string pair. The payload size depends on the | +| |(algorithm string, param_id) pair; see the per-algorithm | +| |sections below. | ++------------------+-----------------------------------------------------------+ +|Return values | ++------------------+-----------------------------------------------------------+ +|Name |Description | ++------------------+-----------------------------------------------------------+ +|int32 status |SUCCESS: if the param_id and buf[] is parsed successfully | +| |by the chosen algorithm string. | +| |NOT_SUPPORTED: if the algorithm string does not have any | +| |matches. | +| |INVALID_PARAMETERS: if the param_id and the buf[] passed | +| |is rejected by the algorithm string. | ++------------------+-----------------------------------------------------------+ + +QCOM_SCMI_GET_PARAM +~~~~~~~~~~~~~~~~~~~ + +message_id: 0x11 +protocol_id: 0x80 + ++------------------+-----------------------------------------------------------+ +|Parameters | ++------------------+-----------------------------------------------------------+ +|Name |Description | ++------------------+-----------------------------------------------------------+ +|uint32 ext_id |Reserved, must be zero. | ++------------------+-----------------------------------------------------------+ +|uint32 algo_low |Lower 32-bit value of the algorithm string. | ++------------------+-----------------------------------------------------------+ +|uint32 algo_high |Upper 32-bit value of the algorithm string. | ++------------------+-----------------------------------------------------------+ +|uint32 param_id |Serves as the token message id for the algorithm string. | ++------------------+-----------------------------------------------------------+ +|uint32 buf[] |Serves as the payload and store of value for the specified | +| |param_id and algorithm string pair. The payload size | +| |depends on the (algorithm string, param_id) pair; see the | +| |per-algorithm sections below. The response payload is | +| |returned in the same buffer, overwriting the request | +| |contents on success. | ++------------------+-----------------------------------------------------------+ +|Return values | ++------------------+-----------------------------------------------------------+ +|Name |Description | ++------------------+-----------------------------------------------------------+ +|int32 status |SUCCESS: if the param_id and buf[] is parsed successfully | +| |by the chosen algorithm string and the result is copied | +| |into buf[]. | +| |NOT_SUPPORTED: if the algorithm string does not have any | +| |matches. | +| |INVALID_PARAMETERS: if the param_id and the buf[] passed | +| |is rejected by the algorithm string. | ++------------------+-----------------------------------------------------------+ +|uint32 buf[] |Holds the payload of the result of the query, returned in | +| |the same buffer used to send the request. Size depends on | +| |the (algorithm string, param_id) pair. | ++------------------+-----------------------------------------------------------+ + +QCOM_SCMI_START_ACTIVITY +~~~~~~~~~~~~~~~~~~~~~~~~ + +message_id: 0x12 +protocol_id: 0x80 + +The activity to be started is defined by the algorithm string; see the +per-algorithm sections (e.g. MEMLAT_START_TIMER) for valid param_ids. + ++------------------+-----------------------------------------------------------+ +|Parameters | ++------------------+-----------------------------------------------------------+ +|Name |Description | ++------------------+-----------------------------------------------------------+ +|uint32 ext_id |Reserved, must be zero. | ++------------------+-----------------------------------------------------------+ +|uint32 algo_low |Lower 32-bit value of the algorithm string. | ++------------------+-----------------------------------------------------------+ +|uint32 algo_high |Upper 32-bit value of the algorithm string. | ++------------------+-----------------------------------------------------------+ +|uint32 param_id |Serves as the token message id for the algorithm string | +| |and is generally used to start the activity performed by | +| |the algorithm string. | ++------------------+-----------------------------------------------------------+ +|uint32 buf[] |Serves as the payload for the specified param_id and | +| |algorithm string pair. The payload size depends on the | +| |(algorithm string, param_id) pair; see the per-algorithm | +| |sections below. | ++------------------+-----------------------------------------------------------+ +|Return values | ++------------------+-----------------------------------------------------------+ +|Name |Description | ++------------------+-----------------------------------------------------------+ +|int32 status |SUCCESS: if the activity performed by the algorithm string | +| |starts successfully, or if it was already running. | +| |NOT_SUPPORTED: if the algorithm string does not have any | +| |matches. | ++------------------+-----------------------------------------------------------+ + +QCOM_SCMI_STOP_ACTIVITY +~~~~~~~~~~~~~~~~~~~~~~~ + +message_id: 0x13 +protocol_id: 0x80 + +The activity to be stopped is defined by the algorithm string; see the +per-algorithm sections (e.g. MEMLAT_STOP_TIMER) for valid param_ids. + ++------------------+-----------------------------------------------------------+ +|Parameters | ++------------------+-----------------------------------------------------------+ +|Name |Description | ++------------------+-----------------------------------------------------------+ +|uint32 ext_id |Reserved, must be zero. | ++------------------+-----------------------------------------------------------+ +|uint32 algo_low |Lower 32-bit value of the algorithm string. | ++------------------+-----------------------------------------------------------+ +|uint32 algo_high |Upper 32-bit value of the algorithm string. | ++------------------+-----------------------------------------------------------+ +|uint32 param_id |Serves as the token message id for the algorithm string | +| |and is generally used to stop the activity performed by | +| |the algorithm string. | ++------------------+-----------------------------------------------------------+ +|uint32 buf[] |Serves as the payload for the specified param_id and | +| |algorithm string pair. The payload size depends on the | +| |(algorithm string, param_id) pair; see the per-algorithm | +| |sections below. | ++------------------+-----------------------------------------------------------+ +|Return values | ++------------------+-----------------------------------------------------------+ +|Name |Description | ++------------------+-----------------------------------------------------------+ +|int32 status |SUCCESS: if the activity performed by the algorithm string | +| |stops successfully, or if it was not running. | +| |NOT_SUPPORTED: if the algorithm string does not have any | +| |matches. | ++------------------+-----------------------------------------------------------+ + +MEMLAT: Memory Latency algorithm +================================ + +The MEMLAT algorithm string (0x4D454D4C4154, ASCII "MEMLAT") is hosted on +the Qualcomm Generic Vendor Protocol and runs on the CPUCP firmware. The +6-byte value is treated as a 64-bit algorithm string and split into two +uint32 fields on the wire: algo_low carries its lower 32 bits and algo_high +its upper 32 bits. +It samples per-CPU performance counters at a configurable period, computes +per memory-group statistics (Instructions-Per-Miss, back-end stall, etc.), +and votes the resulting target frequency to the bus interconnect for DDR, +LLCC and DDR_QOS. Userspace control of the algorithm is exposed via +parameter IDs issued through QCOM_SCMI_SET_PARAM and QCOM_SCMI_GET_PARAM. + +The hw_type field carried in most payloads identifies the memory group: + ++----------+--------------------------------------------------------------+ +|hw_type |Group | ++----------+--------------------------------------------------------------+ +|0 |DDR | ++----------+--------------------------------------------------------------+ +|1 |LLCC | ++----------+--------------------------------------------------------------+ +|2 |DDR_QOS | ++----------+--------------------------------------------------------------+ + +All multi-byte fields below are little-endian, in line with the SCMI +specification. mon_idx selects a monitor within the group (0-based, less +than the firmware-supported maximum). All SET commands return the SCMI +status word; on success it carries SUCCESS, on lookup failure +INVALID_PARAMETERS, and on an unknown param_id NOT_SUPPORTED. + +Frequency units differ per command: MEMLAT_SET_MIN_FREQ and +MEMLAT_SET_MAX_FREQ take kHz for DDR/LLCC, whereas MEMLAT_MON_FREQ_MAP +expresses the resulting vote (v2) in MHz for DDR/LLCC. For DDR_QOS all of +these carry a raw level index (0 / 1) rather than a frequency. + +MEMLAT_SET_MEM_GROUP +~~~~~~~~~~~~~~~~~~~~ + +param_id: 0x10 (16) +command: QCOM_SCMI_SET_PARAM + +Allocates a new memory group on the firmware side and binds it to the +underlying interconnect path (DDR / LLCC / DDR_QOS). + ++------------------+-----------------------------------------------------------+ +|Parameters | ++------------------+-----------------------------------------------------------+ +|Name |Description | ++------------------+-----------------------------------------------------------+ +|uint32 cpumask |Bitmask of HW CPU IDs that contribute counters to this | +| |group (limited to 32 CPUs). | ++------------------+-----------------------------------------------------------+ +|uint32 hw_type |Memory group identifier (0 = DDR, 1 = LLCC, 2 = DDR_QOS). | ++------------------+-----------------------------------------------------------+ +|uint32 mon_type |Reserved for SET_MEM_GROUP (set to 0; populated only on | +| |SET_MONITOR). | ++------------------+-----------------------------------------------------------+ +|uint32 mon_idx |Reserved for SET_MEM_GROUP (set to 0). | ++------------------+-----------------------------------------------------------+ +|char mon_name[20] |Reserved for SET_MEM_GROUP (zero-filled). | ++------------------+-----------------------------------------------------------+ +|Return values | ++------------------+-----------------------------------------------------------+ +|int32 status |SUCCESS: group allocated. | +| |BUSY: no free memory group slot (the firmware-supported | +| |maximum number of groups is already configured). | ++------------------+-----------------------------------------------------------+ + +MEMLAT_SET_MONITOR +~~~~~~~~~~~~~~~~~~ + +param_id: 0x11 (17) +command: QCOM_SCMI_SET_PARAM + +Adds a monitor (a CPU subset that votes within an already-configured +group). + ++------------------+-----------------------------------------------------------+ +|Parameters | ++------------------+-----------------------------------------------------------+ +|Name |Description | ++------------------+-----------------------------------------------------------+ +|uint32 cpumask |Bitmask of HW CPU IDs assigned to this monitor (must be a | +| |subset of the group's cpumask; limited to 32 CPUs). | ++------------------+-----------------------------------------------------------+ +|uint32 hw_type |Memory group identifier the monitor belongs to. | ++------------------+-----------------------------------------------------------+ +|uint32 mon_type |0 = IPM-based latency monitor, 1 = compute (stall-only) | +| |monitor. | ++------------------+-----------------------------------------------------------+ +|uint32 mon_idx |Index of the monitor within the group. | ++------------------+-----------------------------------------------------------+ +|char mon_name[20] |Human-readable monitor name (NUL-terminated, used in | +| |firmware log lines). | ++------------------+-----------------------------------------------------------+ +|Return values | ++------------------+-----------------------------------------------------------+ +|int32 status |SUCCESS: monitor created. | +| |NOT_FOUND: hw_type does not match any configured group, or | +| |the firmware-supported maximum number of monitors already | +| |exist for the group. | ++------------------+-----------------------------------------------------------+ + +MEMLAT_SET_COMMON_EV_MAP +~~~~~~~~~~~~~~~~~~~~~~~~ + +param_id: 0x12 (18) +command: QCOM_SCMI_SET_PARAM + +Configures the common counter IDs (instructions, cycles, stall, etc.) +that the firmware reads on every sample for every CPU. + ++------------------+-----------------------------------------------------------+ +|Parameters | ++------------------+-----------------------------------------------------------+ +|Name |Description | ++------------------+-----------------------------------------------------------+ +|uint32 num_evs |Number of valid entries in cid[]. | ++------------------+-----------------------------------------------------------+ +|uint32 hw_type |Set to 0xFF (sentinel for the common-events case). | ++------------------+-----------------------------------------------------------+ +|uint8 cid[] |Array of CPUCP counter IDs indexed by INST/CYC/CONST_CYC/ | +| |FE_STALL/BE_STALL. 0xFF marks an unused slot. | ++------------------+-----------------------------------------------------------+ +|Return values | ++------------------+-----------------------------------------------------------+ +|int32 status |SUCCESS / INVALID_PARAMETERS if num_evs exceeds the | +| |firmware-supported maximum. | ++------------------+-----------------------------------------------------------+ + +MEMLAT_SET_GRP_EV_MAP +~~~~~~~~~~~~~~~~~~~~~ + +param_id: 0x13 (19) +command: QCOM_SCMI_SET_PARAM + +Configures the per-group event IDs (cache miss / writeback / access) +used by the IPM and write-back computations for the selected hw_type. + ++------------------+-----------------------------------------------------------+ +|Parameters | ++------------------+-----------------------------------------------------------+ +|Name |Description | ++------------------+-----------------------------------------------------------+ +|uint32 num_evs |Number of valid entries in cid[]. | ++------------------+-----------------------------------------------------------+ +|uint32 hw_type |Memory group identifier. | ++------------------+-----------------------------------------------------------+ +|uint8 cid[] |Array of CPUCP counter IDs indexed by MISS/WB/ACC. 0xFF | +| |marks an unused slot. | ++------------------+-----------------------------------------------------------+ +|Return values | ++------------------+-----------------------------------------------------------+ +|int32 status |SUCCESS / INVALID_PARAMETERS if hw_type is unknown or | +| |num_evs exceeds the firmware-supported maximum. | ++------------------+-----------------------------------------------------------+ + +MEMLAT_IPM_CEIL +~~~~~~~~~~~~~~~ + +param_id: 0x17 (23) +command: QCOM_SCMI_SET_PARAM + +Sets the IPM (Instructions-Per-Miss) ceiling for a monitor. CPUs whose +IPM falls at or below this ceiling are considered memory-bound and +contribute their cpufreq into the monitor's voting pool. + ++------------------+-----------------------------------------------------------+ +|Parameters | ++------------------+-----------------------------------------------------------+ +|Name |Description | ++------------------+-----------------------------------------------------------+ +|uint32 hw_type |Memory group identifier. | ++------------------+-----------------------------------------------------------+ +|uint32 mon_idx |Monitor index within the group. | ++------------------+-----------------------------------------------------------+ +|uint32 val |IPM ceiling (instructions per cache miss). | ++------------------+-----------------------------------------------------------+ +|Return values | ++------------------+-----------------------------------------------------------+ +|int32 status |SUCCESS / INVALID_PARAMETERS if (hw_type, mon_idx) does | +| |not match a registered monitor. | ++------------------+-----------------------------------------------------------+ + +MEMLAT_BE_STALL_FLOOR +~~~~~~~~~~~~~~~~~~~~~ + +param_id: 0x19 (25) +command: QCOM_SCMI_SET_PARAM + +Sets the back-end stall floor (in milli-percent: 100000 = 100%) for a +monitor. CPUs whose back-end stall is at or above this floor are +eligible to contribute their cpufreq even if their IPM is above the +ceiling. + ++------------------+-----------------------------------------------------------+ +|Parameters | ++------------------+-----------------------------------------------------------+ +|Name |Description | ++------------------+-----------------------------------------------------------+ +|uint32 hw_type |Memory group identifier. | ++------------------+-----------------------------------------------------------+ +|uint32 mon_idx |Monitor index within the group. | ++------------------+-----------------------------------------------------------+ +|uint32 val |Back-end stall floor in milli-percent (0..100000). | ++------------------+-----------------------------------------------------------+ +|Return values | ++------------------+-----------------------------------------------------------+ +|int32 status |SUCCESS / INVALID_PARAMETERS if (hw_type, mon_idx) does | +| |not match a registered monitor. | ++------------------+-----------------------------------------------------------+ + +MEMLAT_SAMPLE_MS +~~~~~~~~~~~~~~~~ + +param_id: 0x1F (31) +command: QCOM_SCMI_SET_PARAM + +Sets the sampling period (in milliseconds) used by the firmware update +loop. + ++------------------+-----------------------------------------------------------+ +|Parameters | ++------------------+-----------------------------------------------------------+ +|Name |Description | ++------------------+-----------------------------------------------------------+ +|int32 sample_ms |Sampling period in milliseconds. | ++------------------+-----------------------------------------------------------+ +|Return values | ++------------------+-----------------------------------------------------------+ +|int32 status |SUCCESS. | ++------------------+-----------------------------------------------------------+ + +MEMLAT_MON_FREQ_MAP +~~~~~~~~~~~~~~~~~~~ + +param_id: 0x20 (32) +command: QCOM_SCMI_SET_PARAM + +Programs the cpufreq to memfreq voting table for a single monitor. + ++------------------+-----------------------------------------------------------+ +|Parameters | ++------------------+-----------------------------------------------------------+ +|Name |Description | ++------------------+-----------------------------------------------------------+ +|uint32 hw_type |Memory group identifier. | ++------------------+-----------------------------------------------------------+ +|uint32 mon_idx |Monitor index within the group. | ++------------------+-----------------------------------------------------------+ +|uint32 nr_rows |Number of valid rows in tbl[] (must not exceed the | +| |firmware-supported maximum). | ++------------------+-----------------------------------------------------------+ +|struct { |Per-row mapping. v1 is the cpufreq trigger in MHz; v2 is | +| uint16 v1; |the resulting memfreq vote (MHz for DDR/LLCC, a level | +| uint16 v2; |index 0/1 for DDR_QOS). | +|} tbl[] | | ++------------------+-----------------------------------------------------------+ +|Return values | ++------------------+-----------------------------------------------------------+ +|int32 status |SUCCESS / INVALID_PARAMETERS if (hw_type, mon_idx) is | +| |unknown / OUT_OF_RANGE if nr_rows exceeds the | +| |firmware-supported maximum. | ++------------------+-----------------------------------------------------------+ + +MEMLAT_SET_MIN_FREQ +~~~~~~~~~~~~~~~~~~~ + +param_id: 0x21 (33) +command: QCOM_SCMI_SET_PARAM + +Clamps a monitor's vote to a minimum value. Units are kHz for DDR/LLCC and +raw level index for DDR_QOS. + ++------------------+-----------------------------------------------------------+ +|Parameters | ++------------------+-----------------------------------------------------------+ +|Name |Description | ++------------------+-----------------------------------------------------------+ +|uint32 hw_type |Memory group identifier. | ++------------------+-----------------------------------------------------------+ +|uint32 mon_idx |Monitor index within the group. | ++------------------+-----------------------------------------------------------+ +|uint32 val |Minimum frequency: kHz for DDR/LLCC, level for DDR_QOS. | ++------------------+-----------------------------------------------------------+ +|Return values | ++------------------+-----------------------------------------------------------+ +|int32 status |SUCCESS / INVALID_PARAMETERS if (hw_type, mon_idx) does | +| |not match a registered monitor. | ++------------------+-----------------------------------------------------------+ + +MEMLAT_SET_MAX_FREQ +~~~~~~~~~~~~~~~~~~~ + +param_id: 0x22 (34) +command: QCOM_SCMI_SET_PARAM + +Clamps a monitor's vote to a maximum value. Units identical to +MEMLAT_SET_MIN_FREQ. + ++------------------+-----------------------------------------------------------+ +|Parameters | ++------------------+-----------------------------------------------------------+ +|Name |Description | ++------------------+-----------------------------------------------------------+ +|uint32 hw_type |Memory group identifier. | ++------------------+-----------------------------------------------------------+ +|uint32 mon_idx |Monitor index within the group. | ++------------------+-----------------------------------------------------------+ +|uint32 val |Maximum frequency: kHz for DDR/LLCC, level for DDR_QOS. | ++------------------+-----------------------------------------------------------+ +|Return values | ++------------------+-----------------------------------------------------------+ +|int32 status |SUCCESS / INVALID_PARAMETERS if (hw_type, mon_idx) does | +| |not match a registered monitor. | ++------------------+-----------------------------------------------------------+ + +MEMLAT_GET_CUR_FREQ +~~~~~~~~~~~~~~~~~~~ + +param_id: 0x23 (35) +command: QCOM_SCMI_GET_PARAM + +Reads the current target frequency that the firmware is voting for the +selected (hw_type, mon_idx) tuple. The response payload is returned in +the same buffer used to send the request, overwriting it on success. + ++------------------+-----------------------------------------------------------+ +|Parameters | ++------------------+-----------------------------------------------------------+ +|Name |Description | ++------------------+-----------------------------------------------------------+ +|uint32 hw_type |Memory group identifier. | ++------------------+-----------------------------------------------------------+ +|uint32 mon_idx |Monitor index within the group. | ++------------------+-----------------------------------------------------------+ +|Return values | ++------------------+-----------------------------------------------------------+ +|int32 status |SUCCESS / INVALID_PARAMETERS if (hw_type, mon_idx) does | +| |not match a registered monitor. | ++------------------+-----------------------------------------------------------+ +|uint32 cur_freq |Current target frequency in kHz for DDR/LLCC; raw level | +| |(0/1) for DDR_QOS. | ++------------------+-----------------------------------------------------------+ + +MEMLAT_START_TIMER +~~~~~~~~~~~~~~~~~~ + +param_id: 0x24 (36) +command: QCOM_SCMI_START_ACTIVITY + +Starts the firmware sampling and voting loop at the configured +sample_ms interval. Has no payload beyond the QCOM_SCMI_START_ACTIVITY +header. + ++------------------+-----------------------------------------------------------+ +|Return values | ++------------------+-----------------------------------------------------------+ +|int32 status |SUCCESS: timer started (or was already running). | +| |GENERIC_ERROR: events not yet initialized | +| |(MEMLAT_SET_GRP_EV_MAP not called for any group). | +| |NOT_SUPPORTED: invalid param_id under START_ACTIVITY. | ++------------------+-----------------------------------------------------------+ + +MEMLAT_STOP_TIMER +~~~~~~~~~~~~~~~~~ + +param_id: 0x25 (37) +command: QCOM_SCMI_STOP_ACTIVITY + +Suspends the firmware sampling and voting loop. Has no payload beyond +the QCOM_SCMI_STOP_ACTIVITY header. The configured monitors and freq +maps are retained, so a subsequent MEMLAT_START_TIMER resumes voting +without re-programming. + ++------------------+-----------------------------------------------------------+ +|Return values | ++------------------+-----------------------------------------------------------+ +|int32 status |SUCCESS: timer stopped (or was already stopped). | +| |NOT_SUPPORTED: invalid param_id under STOP_ACTIVITY. | ++------------------+-----------------------------------------------------------+ + +MEMLAT_SET_EFFECTIVE_FREQ_METHOD +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +param_id: 0x27 (39) +command: QCOM_SCMI_SET_PARAM + +Selects the algorithm used to derive the per-CPU effective frequency +from the cycle counters. + ++------------------+-----------------------------------------------------------+ +|Parameters | ++------------------+-----------------------------------------------------------+ +|Name |Description | ++------------------+-----------------------------------------------------------+ +|int32 method |0: const-cycles method (CPU cycles / const-cycles, scaled | +| |by the cluster's max frequency). | +| |1: legacy method (CPU cycles / sampling-window time). | ++------------------+-----------------------------------------------------------+ +|Return values | ++------------------+-----------------------------------------------------------+ +|int32 status |SUCCESS / INVALID_PARAMETERS if method is not 0 or 1. | ++------------------+-----------------------------------------------------------+ -- 2.34.1