Re: [RFC 4/7] soc: qcom: Utilize qcom scmi vendor protocol for bus dvfs

Dmitry Baryshkov
2024-01-17T20:41:33Z

On Wed, 17 Jan 2024 at 19:36, Sibi Sankar <quic_sibis@quicinc.com> wrote:
>
> From: Shivnandan Kumar <quic_kshivnan@quicinc.com>
>
> This patch introduces a client driver that interacts with the SCMI QCOM

git grep This.patch Documentation/process/

> vendor protocol and passes on the required tuneables to start various
> features running on the SCMI controller.

Is there any word about the 'memlat'? No. Unless one reads into the
patch, one can not come up with the idea of what is being introduced.

>
> Signed-off-by: Shivnandan Kumar <quic_kshivnan@quicinc.com>
> Co-developed-by: Ramakrishna Gottimukkula <quic_rgottimu@quicinc.com>
> Signed-off-by: Ramakrishna Gottimukkula <quic_rgottimu@quicinc.com>
> Co-developed-by: Amir Vajid <avajid@quicinc.com>
> Signed-off-by: Amir Vajid <avajid@quicinc.com>
> Co-developed-by: Sibi Sankar <quic_sibis@quicinc.com>
> Signed-off-by: Sibi Sankar <quic_sibis@quicinc.com>
> ---
> drivers/soc/qcom/Kconfig | 10 +
> drivers/soc/qcom/Makefile | 1 +
> drivers/soc/qcom/qcom_scmi_client.c | 486 ++++++++++++++++++++++++++++

Should it go to drivers/firmware/arm_scmi instead? Or maybe to drivers/devfreq?

> 3 files changed, 497 insertions(+)
> create mode 100644 drivers/soc/qcom/qcom_scmi_client.c
>
> diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
> index c6ca4de42586..1530558aebfb 100644
> --- a/drivers/soc/qcom/Kconfig
> +++ b/drivers/soc/qcom/Kconfig
> @@ -264,6 +264,16 @@ config QCOM_ICC_BWMON
> the fixed bandwidth votes from cpufreq (CPU nodes) thus achieve high
> memory throughput even with lower CPU frequencies.
>
> +config QCOM_SCMI_CLIENT
> + tristate "Qualcomm Technologies Inc. SCMI client driver"
> + depends on QCOM_SCMI_VENDOR_PROTOCOL || COMPILE_TEST
> + default n
> + help
> + SCMI client driver registers for SCMI QCOM vendor protocol.
> +
> + This driver interacts with the vendor protocol and passes on the required
> + tuneables to start various features running on the SCMI controller.
> +
> config QCOM_INLINE_CRYPTO_ENGINE
> tristate
> select QCOM_SCM
> diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
> index 05b3d54e8dc9..c2a51293c886 100644
> --- a/drivers/soc/qcom/Makefile
> +++ b/drivers/soc/qcom/Makefile
> @@ -32,5 +32,6 @@ 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
> diff --git a/drivers/soc/qcom/qcom_scmi_client.c b/drivers/soc/qcom/qcom_scmi_client.c
> new file mode 100644
> index 000000000000..418aa7900496
> --- /dev/null
> +++ b/drivers/soc/qcom/qcom_scmi_client.c
> @@ -0,0 +1,486 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2024, The Linux Foundation. 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>
> +
> +#define MAX_MEMORY_TYPES 3
> +#define MEMLAT_ALGO_STR 0x74616C6D656D /* "memlat" */
> +#define INVALID_IDX 0xFF
> +#define MAX_NAME_LEN 20
> +#define MAX_MAP_ENTRIES 6
> +#define MAX_MONITOR_CNT 4
> +#define SCMI_VENDOR_MSG_START 3
> +#define SCMI_VENDOR_MSG_MODULE_START 16
> +
> +enum scmi_memlat_protocol_cmd {
> + MEMLAT_SET_LOG_LEVEL = SCMI_VENDOR_MSG_START,
> + MEMLAT_FLUSH_LOGBUF,
> + MEMLAT_SET_MEM_GROUP = SCMI_VENDOR_MSG_MODULE_START,
> + MEMLAT_SET_MONITOR,
> + MEMLAT_SET_COMMON_EV_MAP,
> + MEMLAT_SET_GRP_EV_MAP,
> + MEMLAT_ADAPTIVE_LOW_FREQ,
> + MEMLAT_ADAPTIVE_HIGH_FREQ,
> + MEMLAT_GET_ADAPTIVE_CUR_FREQ,
> + MEMLAT_IPM_CEIL,
> + MEMLAT_FE_STALL_FLOOR,
> + MEMLAT_BE_STALL_FLOOR,
> + MEMLAT_WB_PCT,
> + MEMLAT_IPM_FILTER,
> + MEMLAT_FREQ_SCALE_PCT,
> + MEMLAT_FREQ_SCALE_CEIL_MHZ,
> + MEMLAT_FREQ_SCALE_FLOOR_MHZ,
> + MEMLAT_SAMPLE_MS,
> + MEMLAT_MON_FREQ_MAP,
> + MEMLAT_SET_MIN_FREQ,
> + MEMLAT_SET_MAX_FREQ,
> + MEMLAT_GET_CUR_FREQ,
> + MEMLAT_START_TIMER,
> + MEMLAT_STOP_TIMER,
> + MEMLAT_GET_TIMESTAMP,
> + MEMLAT_MAX_MSG
> +};
> +
> +struct map_table {
> + u16 v1;
> + u16 v2;
> +};
> +

Any documentation for these structures? It won't bite you, but it will
help reviewers and other developers.

> +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;
> +};
> +
> +enum common_ev_idx {
> + INST_IDX,
> + 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];
> + int memory_cnt;
> +};
> +
> +static int get_mask(struct device_node *np, u32 *mask)
> +{
> + struct device_node *dev_phandle;
> + struct device *cpu_dev;
> + int cpu, i = 0;
> + int ret = -ENODEV;
> +
> + dev_phandle = of_parse_phandle(np, "qcom,cpulist", i++);
> + while (dev_phandle) {
> + for_each_possible_cpu(cpu) {
> + cpu_dev = get_cpu_device(cpu);
> + if (cpu_dev && cpu_dev->of_node == dev_phandle) {
> + *mask |= BIT(cpu);
> + ret = 0;
> + break;
> + }
> + }

There is of_cpu_node_to_id(). No need to reinvent it.

> + dev_phandle = of_parse_phandle(np, "qcom,cpulist", i++);
> + }
> +
> + return ret;
> +}
> +
> +static struct cpufreq_memfreq_map *init_cpufreq_memfreq_map(struct device *dev,
> + struct device_node *of_node,
> + u32 *cnt)
> +{
> + int len, nf, i, j;
> + u32 data;
> + struct cpufreq_memfreq_map *tbl;
> + int ret;
> +
> + if (!of_find_property(of_node, "qcom,cpufreq-memfreq-tbl", &len))
> + return NULL;
> + len /= sizeof(data);
> +
> + if (len % 2 || len == 0)
> + return NULL;
> + nf = len / 2;
> +
> + tbl = devm_kzalloc(dev, (nf + 1) * sizeof(struct cpufreq_memfreq_map),
> + GFP_KERNEL);
> + if (!tbl)
> + return NULL;
> +
> + for (i = 0, j = 0; i < nf; i++, j += 2) {
> + ret = of_property_read_u32_index(of_node, "qcom,cpufreq-memfreq-tbl",
> + j, &data);
> + if (ret < 0)
> + return NULL;
> + tbl[i].cpufreq_mhz = data / 1000;
> +
> + ret = of_property_read_u32_index(of_node, "qcom,cpufreq-memfreq-tbl",
> + j + 1, &data);
> + if (ret < 0)
> + return NULL;
> +
> + tbl[i].memfreq_khz = data;
> + pr_debug("Entry%d CPU:%u, Mem:%u\n", i, tbl[i].cpufreq_mhz,
> + tbl[i].memfreq_khz);
> + }
> + *cnt = nf;
> + tbl[i].cpufreq_mhz = 0;

This looks like a lame version of the OPP table.

> +
> + return tbl;
> +}
> +
> +static int process_scmi_memlat_of_node(struct scmi_device *sdev, struct scmi_memlat_info *info)
> +{
> + struct device_node *memlat_np, *memory_np, *monitor_np;
> + struct scmi_memory_info *memory;
> + struct scmi_monitor_info *monitor;
> + int ret = 0, i = 0, j;
> + u32 memfreq[2];
> +
> + of_node_get(sdev->handle->dev->of_node);
> + memlat_np = of_find_node_by_name(sdev->handle->dev->of_node, "memlat");
> +
> + info->memory_cnt = of_get_child_count(memlat_np);
> + if (info->memory_cnt <= 0)
> + pr_err("No memory nodes present\n");
> +
> + for_each_child_of_node(memlat_np, memory_np) {
> + memory = devm_kzalloc(&sdev->dev, sizeof(*memory), GFP_KERNEL);
> + if (!memory) {
> + ret = -ENOMEM;
> + goto err;
> + }
> +
> + ret = of_property_read_u32(memory_np, "reg", &memory->hw_type);
> + if (ret) {
> + pr_err("Failed to read memory type\n");
> + goto err;
> + }
> +
> + memory->monitor_cnt = of_get_child_count(memory_np);
> + if (memory->monitor_cnt <= 0) {
> + pr_err("No monitor nodes present\n");
> + ret = -EINVAL;
> + goto err;
> + }
> +
> + ret = of_property_read_u32_array(memory_np, "freq-table-khz", memfreq, 2);
> + if (ret && (ret != -EINVAL)) {
> + pr_err("Failed to read min/max freq %d\n", ret);
> + goto err;
> + }

foo-min-frequency and foo-max-frequency please.

> +
> + memory->min_freq = memfreq[0];
> + memory->max_freq = memfreq[1];
> + info->memory[i] = memory;
> + j = 0;
> + i++;
> +
> + for_each_child_of_node(memory_np, monitor_np) {
> + 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-mon")) ? 1 : 0;
> + monitor->ipm_ceil = (of_property_read_bool(monitor_np, "qcom,compute-mon")) ? 0 : 20000000;

Huh?

> +
> + if (get_mask(monitor_np, &monitor->mask)) {
> + pr_err("Failed to populate cpu mask %d\n", ret);
> + goto err;
> + }
> +
> + monitor->freq_map = init_cpufreq_memfreq_map(&sdev->dev, monitor_np,
> + &monitor->freq_map_len);
> + snprintf(monitor->mon_name, MAX_NAME_LEN, "monitor-%d", j);
> + monitor->mon_idx = j;
> +
> + memory->monitor[j] = monitor;
> + j++;
> + }
> + }
> +
> + return 0;
> +
> +err:
> + of_node_put(memlat_np);
> +
> + 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[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 ret;
> +}
> +
> +static int configure_cpucp_grp(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) {
> + pr_err("Failed to configure mem type %d\n", memory->hw_type);
> + return ret;
> + }
> +
> + 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) {
> + pr_err("Failed to configure event map for mem type %d\n", memory->hw_type);
> + return ret;
> + }
> +
> + return ret;
> +}
> +
> +static int configure_cpucp_mon(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) {
> + pr_err("Failed to configure monitor %s\n", monitor->mon_name);
> + return ret;
> + }
> +
> + 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) {
> + pr_err("Failed to set ipm ceil for %s\n", monitor->mon_name);
> + return ret;
> + }
> +
> + 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 / 1000;
> + }

So this table goes 1:1 to the firmware? Is it going to be the same for
all versions of the SoC? If so, it might be better to turn it into the
static data inside the driver. If it doesn't change, there is no need
to put it to DT.

> + ret = ops->set_param(info->ph, &map_msg, MEMLAT_ALGO_STR, MEMLAT_MON_FREQ_MAP,
> + sizeof(map_msg));
> + if (ret < 0) {
> + pr_err("Failed to configure freq_map for %s\n", monitor->mon_name);
> + return ret;
> + }
> +
> + 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) {
> + pr_err("Failed to set min_freq for %s\n", monitor->mon_name);
> + return ret;
> + }
> +
> + 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)
> + pr_err("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_sample_ms = 8;
> + 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)
> + pr_err("Failed to configure common events: %d\n", ret);
> +
> + info->ph = ph;
> + info->ops = ops;
> +
> + ret = configure_cpucp_common_events(info);
> + if (ret < 0)
> + pr_err("Failed to configure common events: %d\n", ret);
> +
> + for (i = 0; i < info->memory_cnt; i++) {
> + ret = configure_cpucp_grp(info, i);
> + if (ret < 0)
> + pr_err("Failed to configure mem group: %d\n", ret);
> +
> + for (j = 0; j < info->memory[i]->monitor_cnt; j++) {
> + /* Configure per monitor parameters */
> + ret = configure_cpucp_mon(info, i, j);
> + if (ret < 0)
> + pr_err("Failed to configure monitor: %d\n", ret);
> + }
> + }
> +
> + ret = ops->set_param(ph, &cpucp_sample_ms, MEMLAT_ALGO_STR, MEMLAT_SAMPLE_MS,
> + sizeof(cpucp_sample_ms));
> + if (ret < 0)
> + pr_err("Failed to set cpucp sample_ms ret = %d\n", ret);
> +
> + /* Start sampling and voting timer */
> + ret = ops->start_activity(ph, NULL, MEMLAT_ALGO_STR, MEMLAT_START_TIMER, 0);
> + if (ret < 0)
> + pr_err("Error in starting the mem group timer %d\n", ret);
> +
> + dev_set_drvdata(&sdev->dev, info);
> +
> + return ret;
> +}
> +
> +static int scmi_client_probe(struct scmi_device *sdev)
> +{
> + cpucp_memlat_init(sdev);
> +
> + return 0;
> +}
> +
> +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");
> --
> 2.34.1
>
>

--
With best wishes
Dmitry