Re: [RFC V3 3/4] soc: qcom: Introduce SCMI based Memlat (Memory Latency) governor
From: Cristian Marussi
Date: Wed Jul 10 2024 - 07:37:08 EST
On Wed, Jul 03, 2024 at 12:44:39AM +0530, Sibi Sankar wrote:
> Introduce a client driver that uses the memlat algorithm string hosted
> on ARM SCMI QCOM Vendor Protocol to detect memory latency workloads and
> control frequency/level of the various memory buses (DDR/LLCC/DDR_QOS).
>
> Co-developed-by: Shivnandan Kumar <quic_kshivnan@xxxxxxxxxxx>
> Signed-off-by: Shivnandan Kumar <quic_kshivnan@xxxxxxxxxxx>
> Co-developed-by: Ramakrishna Gottimukkula <quic_rgottimu@xxxxxxxxxxx>
> Signed-off-by: Ramakrishna Gottimukkula <quic_rgottimu@xxxxxxxxxxx>
> Co-developed-by: Amir Vajid <avajid@xxxxxxxxxxx>
> Signed-off-by: Amir Vajid <avajid@xxxxxxxxxxx>
> Signed-off-by: Sibi Sankar <quic_sibis@xxxxxxxxxxx>
> ---
>
Hi Sibi,
just a few remarks down below...
> V2:
> * Make driver changes to the accommodate bindings changes. [Rob]
> * Replace explicit of_node_put with _free.
>
> drivers/soc/qcom/Kconfig | 12 +
> drivers/soc/qcom/Makefile | 1 +
> drivers/soc/qcom/qcom_scmi_client.c | 583 ++++++++++++++++++++++++++++
> 3 files changed, 596 insertions(+)
> create mode 100644 drivers/soc/qcom/qcom_scmi_client.c
>
> diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
> index 432c85bd8ad4..b253504bd386 100644
> --- a/drivers/soc/qcom/Kconfig
> +++ b/drivers/soc/qcom/Kconfig
> @@ -294,4 +294,16 @@ config QCOM_PBS
> This module provides the APIs to the client drivers that wants to send the
> PBS trigger event to the PBS RAM.
>
> +config QCOM_SCMI_CLIENT
> + tristate "Qualcomm Technologies Inc. SCMI client driver"
> + depends on ARM_SCMI_PROTOCOL_VENDOR_QCOM || COMPILE_TEST
> + default n
I think default is N by..ehm.. default...so it is implicit and not needed to be specified
> + help
> + This driver uses the memlat algorithm string hosted on QCOM SCMI
> + Vendor Protocol to detect memory latency workloads and control
> + frequency/level of the various memory buses (DDR/LLCC/DDR_QOS).
> +
> + This driver defines/documents the parameter IDs used while configuring
> + the memory buses.
> +
> endmenu
> diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
> index d3560f861085..8a2e832d1d5d 100644
> --- a/drivers/soc/qcom/Makefile
> +++ b/drivers/soc/qcom/Makefile
> @@ -35,6 +35,7 @@ obj-$(CONFIG_QCOM_APR) += apr.o
> obj-$(CONFIG_QCOM_LLCC) += llcc-qcom.o
> obj-$(CONFIG_QCOM_KRYO_L2_ACCESSORS) += kryo-l2-accessors.o
> obj-$(CONFIG_QCOM_ICC_BWMON) += icc-bwmon.o
> +obj-$(CONFIG_QCOM_SCMI_CLIENT) += qcom_scmi_client.o
> qcom_ice-objs += ice.o
> obj-$(CONFIG_QCOM_INLINE_CRYPTO_ENGINE) += qcom_ice.o
> obj-$(CONFIG_QCOM_PBS) += qcom-pbs.o
> diff --git a/drivers/soc/qcom/qcom_scmi_client.c b/drivers/soc/qcom/qcom_scmi_client.c
> new file mode 100644
> index 000000000000..8369b415c0ab
> --- /dev/null
> +++ b/drivers/soc/qcom/qcom_scmi_client.c
> @@ -0,0 +1,583 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2024, Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#include <linux/cpu.h>
> +#include <linux/err.h>
> +#include <linux/errno.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/qcom_scmi_vendor.h>
> +#include <linux/scmi_protocol.h>
> +#include <linux/units.h>
> +#include <dt-bindings/soc/qcom,scmi-vendor.h>
> +
> +#define MEMLAT_ALGO_STR 0x4D454D4C4154 /* MEMLAT */
> +#define INVALID_IDX 0xff
> +#define MAX_MEMORY_TYPES 3
> +#define MAX_MONITOR_CNT 4
> +#define MAX_NAME_LEN 20
> +#define MAX_MAP_ENTRIES 7
> +#define CPUCP_DEFAULT_SAMPLING_PERIOD_MS 4
> +#define CPUCP_DEFAULT_FREQ_METHOD 1
> +
> +/**
> + * scmi_memlat_protocol_cmd - parameter_ids supported by the "MEMLAT" algo_str hosted
> + * by the Qualcomm SCMI Vendor Protocol on the SCMI controller.
> + *
> + * MEMLAT (Memory Latency) monitors the counters to detect memory latency bound workloads
> + * and scales the frequency/levels of the memory buses accordingly.
> + *
> + * @MEMLAT_SET_MEM_GROUP: initializes the frequency/level scaling functions for the memory bus.
> + * @MEMLAT_SET_MONITOR: configures the monitor to work on a specific memory bus.
> + * @MEMLAT_SET_COMMON_EV_MAP: set up common counters used to monitor the cpu frequency.
> + * @MEMLAT_SET_GRP_EV_MAP: set up any specific counters used to monitor the memory bus.
> + * @MEMLAT_IPM_CEIL: set the IPM (Instruction Per Misses) ceiling per monitor.
> + * @MEMLAT_SAMPLE_MS: set the sampling period for all the monitors.
> + * MEMLAT_MON_FREQ_MAP: setup the cpufreq to memfreq map.
> + * MEMLAT_SET_MIN_FREQ: set the max frequency of the memory bus.
> + * MEMLAT_SET_MAX_FREQ: set the min frequency of the memory bus.
> + * MEMLAT_START_TIMER: start all the monitors with the requested sampling period.
> + * MEMLAT_START_TIMER: stop all the running monitors.
> + * MEMLAT_SET_EFFECTIVE_FREQ_METHOD: set the method used to determine cpu frequency.
> + */
> +enum scmi_memlat_protocol_cmd {
> + MEMLAT_SET_MEM_GROUP = 16,
> + MEMLAT_SET_MONITOR,
> + MEMLAT_SET_COMMON_EV_MAP,
> + MEMLAT_SET_GRP_EV_MAP,
> + MEMLAT_IPM_CEIL = 23,
> + MEMLAT_SAMPLE_MS = 31,
> + MEMLAT_MON_FREQ_MAP,
> + MEMLAT_SET_MIN_FREQ,
> + MEMLAT_SET_MAX_FREQ,
> + MEMLAT_START_TIMER = 36,
> + MEMLAT_STOP_TIMER,
> + MEMLAT_SET_EFFECTIVE_FREQ_METHOD = 39,
> +};
> +
> +struct map_table {
> + u16 v1;
> + u16 v2;
> +};
> +
> +struct map_param_msg {
> + u32 hw_type;
> + u32 mon_idx;
> + u32 nr_rows;
> + struct map_table tbl[MAX_MAP_ENTRIES];
> +} __packed;
> +
> +struct node_msg {
> + u32 cpumask;
> + u32 hw_type;
> + u32 mon_type;
> + u32 mon_idx;
> + char mon_name[MAX_NAME_LEN];
> +};
> +
> +struct scalar_param_msg {
> + u32 hw_type;
> + u32 mon_idx;
> + u32 val;
> +};
...just reiterating that all of these message payload descriptors
completely ignore endianity....but if it is fine for you I wont complain :D
> +
> +enum common_ev_idx {
> + INST_IDX,
> + CYC_IDX,
> + CONST_CYC_IDX,
> + FE_STALL_IDX,
> + BE_STALL_IDX,
> + NUM_COMMON_EVS
> +};
> +
> +enum grp_ev_idx {
> + MISS_IDX,
> + WB_IDX,
> + ACC_IDX,
> + NUM_GRP_EVS
> +};
> +
> +#define EV_CPU_CYCLES 0
> +#define EV_INST_RETIRED 2
> +#define EV_L2_D_RFILL 5
> +
> +struct ev_map_msg {
> + u32 num_evs;
> + u32 hw_type;
> + u32 cid[NUM_COMMON_EVS];
> +};
> +
> +struct cpufreq_memfreq_map {
> + unsigned int cpufreq_mhz;
> + unsigned int memfreq_khz;
> +};
> +
> +struct scmi_monitor_info {
> + struct cpufreq_memfreq_map *freq_map;
> + char mon_name[MAX_NAME_LEN];
> + u32 mon_idx;
> + u32 mon_type;
> + u32 ipm_ceil;
> + u32 mask;
> + u32 freq_map_len;
> +};
> +
> +struct scmi_memory_info {
> + struct scmi_monitor_info *monitor[MAX_MONITOR_CNT];
> + u32 hw_type;
> + int monitor_cnt;
> + u32 min_freq;
> + u32 max_freq;
> +};
> +
> +struct scmi_memlat_info {
> + struct scmi_protocol_handle *ph;
> + const struct qcom_scmi_vendor_ops *ops;
> + struct scmi_memory_info *memory[MAX_MEMORY_TYPES];
> + u32 cluster_info[NR_CPUS];
> + int memory_cnt;
> +};
> +
> +static int populate_cluster_info(u32 *cluster_info)
> +{
> + char name[MAX_NAME_LEN];
> + int i = 0;
> +
> + struct device_node *cn __free(device_node) = of_find_node_by_path("/cpus");
> + if (!cn)
> + return -ENODEV;
> +
> + struct device_node *map __free(device_node) = of_get_child_by_name(cn, "cpu-map");
> + if (!map)
> + return -ENODEV;
> +
> + do {
> + snprintf(name, sizeof(name), "cluster%d", i);
> + struct device_node *c __free(device_node) = of_get_child_by_name(map, name);
> + if (!c)
> + break;
> +
> + *(cluster_info + i) = of_get_child_count(c);
> + i++;
> + } while (1);
> +
> + return 0;
> +}
> +
> +static int populate_physical_mask(struct device_node *np, u32 *mask, u32 *cluster_info)
> +{
> + struct device_node *dev_phandle;
> + int cpu, i = 0, physical_id;
> +
> + do {
> + dev_phandle = of_parse_phandle(np, "cpus", i++);
Shouldn't dev_phandle ...
> + cpu = of_cpu_node_to_id(dev_phandle);
and cpu be of_put somewhere in this loop ? (explicitly or by __free magic)
> + if (cpu != -ENODEV) {
> + physical_id = topology_core_id(cpu);
> + for (int j = 0; j < topology_cluster_id(cpu); j++)
> + physical_id += *(cluster_info + j);
> + *mask |= BIT(physical_id);
> + }
> + } while (dev_phandle);
> +
> + return 0;
> +}
> +
> +static struct cpufreq_memfreq_map *init_cpufreq_memfreq_map(struct device *dev,
> + struct scmi_memory_info *memory,
> + struct device_node *of_node,
> + u32 *cnt)
> +{
> + struct device_node *tbl_np, *opp_np;
> + struct cpufreq_memfreq_map *tbl;
> + int ret, i = 0;
> + u32 level, len;
> + u64 rate;
> +
> + tbl_np = of_parse_phandle(of_node, "operating-points-v2", 0);
> + if (!tbl_np)
> + return ERR_PTR(-ENODEV);
> +
> + len = min(of_get_available_child_count(tbl_np), MAX_MAP_ENTRIES);
> + if (len == 0)
> + return ERR_PTR(-ENODEV);
of_put or __free magic ?
> +
> + tbl = devm_kzalloc(dev, (len + 1) * sizeof(struct cpufreq_memfreq_map),
> + GFP_KERNEL);
> + if (!tbl)
of_put or __free magic ?
> + return ERR_PTR(-ENOMEM);
> +
> + for_each_available_child_of_node(tbl_np, opp_np) {
> + ret = of_property_read_u64_index(opp_np, "opp-hz", 0, &rate);
> + if (ret < 0)
same
> + return ERR_PTR(ret);
> +
> + tbl[i].cpufreq_mhz = rate / HZ_PER_MHZ;
> +
> + if (memory->hw_type != QCOM_MEM_TYPE_DDR_QOS) {
> + ret = of_property_read_u64_index(opp_np, "opp-hz", 1, &rate);
> + if (ret < 0)
> + return ERR_PTR(ret);
> +
> + tbl[i].memfreq_khz = rate / HZ_PER_KHZ;
> + } else {
> + ret = of_property_read_u32(opp_np, "opp-level", &level);
> + if (ret < 0)
> + return ERR_PTR(ret);
> +
> + tbl[i].memfreq_khz = level;
> + }
> +
> + dev_dbg(dev, "Entry%d CPU:%u, Mem:%u\n", i, tbl[i].cpufreq_mhz, tbl[i].memfreq_khz);
> + i++;
> + }
> + *cnt = len;
> + tbl[i].cpufreq_mhz = 0;
> +
> + return tbl;
> +}
> +
> +static int process_scmi_memlat_of_node(struct scmi_device *sdev, struct scmi_memlat_info *info)
> +{
> + struct scmi_monitor_info *monitor;
> + struct scmi_memory_info *memory;
> + char name[MAX_NAME_LEN];
> + u64 memfreq[2];
> + int ret;
> +
> + ret = populate_cluster_info(info->cluster_info);
> + if (ret < 0) {
> + dev_err_probe(&sdev->dev, ret, "failed to populate cluster info\n");
> + goto err;
> + }
> +
> + of_node_get(sdev->handle->dev->of_node);
>From your DT bindings it seems to me that all of your vendor DT props
are (correctly) nested inside your own protocol@80 node right ?
So why you are getting and walking the entire firmware/scmi top node
with sdev->handle->dev->of_node ?
...it should be enough to get and walk sdev->dev.of_node which is the
device built around your protocol@80 node ...
> + do {
> + snprintf(name, sizeof(name), "memory-%d", info->memory_cnt);
> + struct device_node *memory_np __free(device_node) =
> + of_find_node_by_name(sdev->handle->dev->of_node, name);
same here
of_find_by_name(sdev->dev.of_node);
... am I missing something ?
> +
> + if (!memory_np)
> + break;
> +
> + memory = devm_kzalloc(&sdev->dev, sizeof(*memory), GFP_KERNEL);
> + if (!memory) {
> + ret = -ENOMEM;
> + goto err;
> + }
> +
> + ret = of_property_read_u32(memory_np, "qcom,memory-type", &memory->hw_type);
> + if (ret) {
> + dev_err_probe(&sdev->dev, ret, "failed to read memory type\n");
> + goto err;
> + }
> +
> + ret = of_property_read_u64_array(memory_np, "freq-table-hz", memfreq, 2);
> + if (ret && (ret != -EINVAL)) {
> + dev_err_probe(&sdev->dev, ret, "failed to read min/max freq\n");
> + goto err;
> + }
> +
> + if (memory->hw_type != QCOM_MEM_TYPE_DDR_QOS) {
> + memory->min_freq = memfreq[0] / HZ_PER_KHZ;
> + memory->max_freq = memfreq[1] / HZ_PER_KHZ;
> + } else {
> + memory->min_freq = memfreq[0];
> + memory->max_freq = memfreq[1];
> + }
> + info->memory[info->memory_cnt++] = memory;
> +
> + do {
> + snprintf(name, sizeof(name), "monitor-%d", memory->monitor_cnt);
> + struct device_node *monitor_np __free(device_node) =
> + of_get_child_by_name(memory_np, name);
> +
> + if (!monitor_np)
> + break;
> +
> + monitor = devm_kzalloc(&sdev->dev, sizeof(*monitor), GFP_KERNEL);
> + if (!monitor) {
> + ret = -ENOMEM;
> + goto err;
> + }
> +
> + monitor->mon_type = of_property_read_bool(monitor_np, "qcom,compute-type");
> + if (!monitor->mon_type) {
> + ret = of_property_read_u32(monitor_np, "qcom,ipm-ceil",
> + &monitor->ipm_ceil);
> + if (ret) {
> + dev_err_probe(&sdev->dev, ret,
> + "failed to read IPM ceiling\n");
> + goto err;
> + }
> + }
> +
> + /*
> + * Variants of the SoC having reduced number of cpus operate
> + * with the same number of logical cpus but the physical
> + * cpu disabled will differ between parts. Calculate the
> + * physical cpu number using cluster information instead.
> + */
> + ret = populate_physical_mask(monitor_np, &monitor->mask,
> + info->cluster_info);
> + if (ret < 0) {
> + dev_err_probe(&sdev->dev, ret, "failed to populate cpu mask\n");
> + goto err;
> + }
> +
> + monitor->freq_map = init_cpufreq_memfreq_map(&sdev->dev, memory, monitor_np,
> + &monitor->freq_map_len);
> + if (IS_ERR(monitor->freq_map)) {
> + dev_err_probe(&sdev->dev, PTR_ERR(monitor->freq_map),
> + "failed to populate cpufreq-memfreq map\n");
> + goto err;
> + }
> +
> + strscpy(monitor->mon_name, name, sizeof(monitor->mon_name));
> + monitor->mon_idx = memory->monitor_cnt;
> +
> + memory->monitor[memory->monitor_cnt++] = monitor;
> + } while (1);
> +
> + if (!memory->monitor_cnt) {
> + ret = -EINVAL;
> + dev_err_probe(&sdev->dev, ret, "failed to find monitor nodes\n");
> + goto err;
> + }
> + } while (1);
> +
> + if (!info->memory_cnt) {
> + ret = -EINVAL;
> + dev_err_probe(&sdev->dev, ret, "failed to find memory nodes\n");
> + }
> +
> +err:
> + of_node_put(sdev->handle->dev->of_node);
> +
> + return ret;
> +}
> +
> +static int configure_cpucp_common_events(struct scmi_memlat_info *info)
> +{
> + const struct qcom_scmi_vendor_ops *ops = info->ops;
> + u8 ev_map[NUM_COMMON_EVS];
> + struct ev_map_msg msg;
> + int ret;
> +
> + memset(ev_map, 0xFF, NUM_COMMON_EVS);
> +
> + msg.num_evs = NUM_COMMON_EVS;
> + msg.hw_type = INVALID_IDX;
> + msg.cid[INST_IDX] = EV_INST_RETIRED;
> + msg.cid[CYC_IDX] = EV_CPU_CYCLES;
> + msg.cid[CONST_CYC_IDX] = INVALID_IDX;
> + msg.cid[FE_STALL_IDX] = INVALID_IDX;
> + msg.cid[BE_STALL_IDX] = INVALID_IDX;
> +
> + ret = ops->set_param(info->ph, &msg, MEMLAT_ALGO_STR, MEMLAT_SET_COMMON_EV_MAP,
> + sizeof(msg));
return ops->set_param(...
> + return ret;
> +}
> +
> +static int configure_cpucp_grp(struct device *dev, struct scmi_memlat_info *info, int memory_index)
> +{
> + const struct qcom_scmi_vendor_ops *ops = info->ops;
> + struct scmi_memory_info *memory = info->memory[memory_index];
> + struct ev_map_msg ev_msg;
> + u8 ev_map[NUM_GRP_EVS];
> + struct node_msg msg;
> + int ret;
> +
> + msg.cpumask = 0;
> + msg.hw_type = memory->hw_type;
> + msg.mon_type = 0;
> + msg.mon_idx = 0;
> + ret = ops->set_param(info->ph, &msg, MEMLAT_ALGO_STR, MEMLAT_SET_MEM_GROUP, sizeof(msg));
> + if (ret < 0) {
> + dev_err_probe(dev, ret, "failed to configure mem type %d\n", memory->hw_type);
> + return ret;
return dev_err_probe(...
> + }
> +
> + memset(ev_map, 0xFF, NUM_GRP_EVS);
> + ev_msg.num_evs = NUM_GRP_EVS;
> + ev_msg.hw_type = memory->hw_type;
> + ev_msg.cid[MISS_IDX] = EV_L2_D_RFILL;
> + ev_msg.cid[WB_IDX] = INVALID_IDX;
> + ev_msg.cid[ACC_IDX] = INVALID_IDX;
> + ret = ops->set_param(info->ph, &ev_msg, MEMLAT_ALGO_STR, MEMLAT_SET_GRP_EV_MAP,
> + sizeof(ev_msg));
> + if (ret < 0) {
> + dev_err_probe(dev, ret,
> + "failed to configure event map for mem type %d\n", memory->hw_type);
> + return ret;
return dev_err_probe(...
> + }
> +
> + return ret;
> +}
> +
> +static int configure_cpucp_mon(struct device *dev, struct scmi_memlat_info *info,
> + int memory_index, int monitor_index)
> +{
> + const struct qcom_scmi_vendor_ops *ops = info->ops;
> + struct scmi_memory_info *memory = info->memory[memory_index];
> + struct scmi_monitor_info *monitor = memory->monitor[monitor_index];
> + struct scalar_param_msg scalar_msg;
> + struct map_param_msg map_msg;
> + struct node_msg msg;
> + int ret;
> + int i;
> +
> + msg.cpumask = monitor->mask;
> + msg.hw_type = memory->hw_type;
> + msg.mon_type = monitor->mon_type;
> + msg.mon_idx = monitor->mon_idx;
> + strscpy(msg.mon_name, monitor->mon_name, sizeof(msg.mon_name));
> + ret = ops->set_param(info->ph, &msg, MEMLAT_ALGO_STR, MEMLAT_SET_MONITOR, sizeof(msg));
> + if (ret < 0) {
> + dev_err_probe(dev, ret, "failed to configure monitor %s\n", monitor->mon_name);
> + return ret;
return dev_err_probe(...
> + }
> +
> + scalar_msg.hw_type = memory->hw_type;
> + scalar_msg.mon_idx = monitor->mon_idx;
> + scalar_msg.val = monitor->ipm_ceil;
> + ret = ops->set_param(info->ph, &scalar_msg, MEMLAT_ALGO_STR, MEMLAT_IPM_CEIL,
> + sizeof(scalar_msg));
> + if (ret < 0) {
> + dev_err_probe(dev, ret, "failed to set ipm ceil for %s\n", monitor->mon_name);
> + return ret;
return dev_err_probe(...
> + }
> +
> + map_msg.hw_type = memory->hw_type;
> + map_msg.mon_idx = monitor->mon_idx;
> + map_msg.nr_rows = monitor->freq_map_len;
> + for (i = 0; i < monitor->freq_map_len; i++) {
> + map_msg.tbl[i].v1 = monitor->freq_map[i].cpufreq_mhz;
> + map_msg.tbl[i].v2 = monitor->freq_map[i].memfreq_khz;
> + }
> + ret = ops->set_param(info->ph, &map_msg, MEMLAT_ALGO_STR, MEMLAT_MON_FREQ_MAP,
> + sizeof(map_msg));
> + if (ret < 0) {
> + dev_err_probe(dev, ret, "failed to configure freq_map for %s\n", monitor->mon_name);
> + return ret;
return dev_err_probe(...
> + }
> +
> + scalar_msg.hw_type = memory->hw_type;
> + scalar_msg.mon_idx = monitor->mon_idx;
> + scalar_msg.val = memory->min_freq;
> + ret = ops->set_param(info->ph, &scalar_msg, MEMLAT_ALGO_STR, MEMLAT_SET_MIN_FREQ,
> + sizeof(scalar_msg));
> + if (ret < 0) {
> + dev_err_probe(dev, ret, "failed to set min_freq for %s\n", monitor->mon_name);
> + return ret;
return dev_err_probe(...
> + }
> +
> + scalar_msg.hw_type = memory->hw_type;
> + scalar_msg.mon_idx = monitor->mon_idx;
> + scalar_msg.val = memory->max_freq;
> + ret = ops->set_param(info->ph, &scalar_msg, MEMLAT_ALGO_STR, MEMLAT_SET_MAX_FREQ,
> + sizeof(scalar_msg));
> + if (ret < 0)
> + dev_err_probe(dev, ret, "failed to set max_freq for %s\n", monitor->mon_name);
> +
> + return ret;
> +}
> +
> +static int cpucp_memlat_init(struct scmi_device *sdev)
> +{
> + const struct scmi_handle *handle = sdev->handle;
> + const struct qcom_scmi_vendor_ops *ops;
> + struct scmi_protocol_handle *ph;
> + struct scmi_memlat_info *info;
> + u32 cpucp_freq_method = CPUCP_DEFAULT_FREQ_METHOD;
> + u32 cpucp_sample_ms = CPUCP_DEFAULT_SAMPLING_PERIOD_MS;
> + int ret, i, j;
> +
> + if (!handle)
> + return -ENODEV;
> +
> + ops = handle->devm_protocol_get(sdev, QCOM_SCMI_VENDOR_PROTOCOL, &ph);
> + if (IS_ERR(ops))
> + return PTR_ERR(ops);
> +
> + info = devm_kzalloc(&sdev->dev, sizeof(*info), GFP_KERNEL);
> + if (!info)
> + return -ENOMEM;
> +
> + ret = process_scmi_memlat_of_node(sdev, info);
> + if (ret)
> + return ret;
> +
> + info->ph = ph;
> + info->ops = ops;
> +
> + /* Configure common events ids */
> + ret = configure_cpucp_common_events(info);
> + if (ret < 0) {
> + dev_err_probe(&sdev->dev, ret, "failed to configure common events\n");
> + return ret;
return dev_err_probe(...
> + }
> +
> + for (i = 0; i < info->memory_cnt; i++) {
> + /* Configure per group parameters */
> + ret = configure_cpucp_grp(&sdev->dev, info, i);
> + if (ret < 0)
> + return ret;
> +
> + for (j = 0; j < info->memory[i]->monitor_cnt; j++) {
> + /* Configure per monitor parameters */
> + ret = configure_cpucp_mon(&sdev->dev, info, i, j);
> + if (ret < 0)
> + return ret;
> + }
> + }
> +
> + /* Set loop sampling time */
> + ret = ops->set_param(ph, &cpucp_sample_ms, MEMLAT_ALGO_STR, MEMLAT_SAMPLE_MS,
> + sizeof(cpucp_sample_ms));
> + if (ret < 0) {
> + dev_err_probe(&sdev->dev, ret, "failed to set sample_ms\n");
> + return ret;
return dev_err_probe(...
> + }
> +
> + /* Set the effective cpu frequency calculation method */
> + ret = ops->set_param(ph, &cpucp_freq_method, MEMLAT_ALGO_STR,
> + MEMLAT_SET_EFFECTIVE_FREQ_METHOD, sizeof(cpucp_freq_method));
> + if (ret < 0) {
> + dev_err_probe(&sdev->dev, ret, "failed to set effective frequency calc method\n");
> + return ret;
return dev_err_probe(...
> + }
> +
> + /* Start sampling and voting timer */
> + ret = ops->start_activity(ph, NULL, MEMLAT_ALGO_STR, MEMLAT_START_TIMER, 0);
> + if (ret < 0)
> + dev_err_probe(&sdev->dev, ret, "failed to start memory group timer\n");
> +
> + return ret;
> +}
> +
> +static int scmi_client_probe(struct scmi_device *sdev)
> +{
> + return cpucp_memlat_init(sdev);
> +}
> +
> +static const struct scmi_device_id scmi_id_table[] = {
> + { .protocol_id = QCOM_SCMI_VENDOR_PROTOCOL, .name = "qcom_scmi_vendor_protocol" },
> + { },
> +};
> +MODULE_DEVICE_TABLE(scmi, scmi_id_table);
> +
> +static struct scmi_driver qcom_scmi_client_drv = {
> + .name = "qcom-scmi-driver",
> + .probe = scmi_client_probe,
> + .id_table = scmi_id_table,
> +};
> +module_scmi_driver(qcom_scmi_client_drv);
> +
> +MODULE_DESCRIPTION("QTI SCMI client driver");
> +MODULE_LICENSE("GPL");
Thanks,
Cristian