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From:   Georgi Djakov <georgi.djakov@linaro.org>
Subject: Re: [RFC PATCH 3/4] interconnect: qcom: Refactor icc rpmh support
To:     David Dai <daidavid1@codeaurora.org>, bjorn.andersson@linaro.org,
        robh+dt@kernel.org
Cc:     evgreen@google.com, sboyd@kernel.org, ilina@codeaurora.org,
        seansw@qti.qualcomm.com, elder@linaro.org,
        linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
        linux-arm-msm@vger.kernel.org, linux-pm@vger.kernel.org
References: <1571278852-8023-1-git-send-email-daidavid1@codeaurora.org>
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Date:   Mon, 28 Oct 2019 18:31:47 +0200
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Hi David,

On 17.10.19 г. 5:20 ч., David Dai wrote:
> Add bcm voter driver and add support for RPMh specific interconnect
> providers so that they may be re-used for icc-next RPMh based provider
> drivers.

For icc-next? You mean to be re-used for other RPMh based drivers?

> 
> Signed-off-by: David Dai <daidavid1@codeaurora.org>
> ---
>  drivers/interconnect/qcom/Kconfig     |   8 +
>  drivers/interconnect/qcom/Makefile    |   4 +
>  drivers/interconnect/qcom/bcm-voter.c | 355 ++++++++++++++++++++++++++++++++++
>  drivers/interconnect/qcom/bcm-voter.h |  28 +++
>  drivers/interconnect/qcom/icc-rpmh.c  | 154 +++++++++++++++
>  drivers/interconnect/qcom/icc-rpmh.h  | 150 ++++++++++++++
>  6 files changed, 699 insertions(+)
>  create mode 100644 drivers/interconnect/qcom/bcm-voter.c
>  create mode 100644 drivers/interconnect/qcom/bcm-voter.h
>  create mode 100644 drivers/interconnect/qcom/icc-rpmh.c
>  create mode 100644 drivers/interconnect/qcom/icc-rpmh.h
> 
> diff --git a/drivers/interconnect/qcom/Kconfig b/drivers/interconnect/qcom/Kconfig
> index 6ab4012..8ff255d 100644
> --- a/drivers/interconnect/qcom/Kconfig
> +++ b/drivers/interconnect/qcom/Kconfig
> @@ -18,9 +18,17 @@ config INTERCONNECT_QCOM_SDM845
>  	tristate "Qualcomm SDM845 interconnect driver"
>  	depends on INTERCONNECT_QCOM
>  	depends on (QCOM_RPMH && QCOM_COMMAND_DB && OF) || COMPILE_TEST
> +	select INTERCONNECT_QCOM_RPMH
> +	select INTERCONNECT_QCOM_BCM_VOTER
>  	help
>  	  This is a driver for the Qualcomm Network-on-Chip on sdm845-based
>  	  platforms.
>  
> +config INTERCONNECT_QCOM_BCM_VOTER
> +	tristate
> +
> +config INTERCONNECT_QCOM_RPMH
> +	tristate
> +>  config INTERCONNECT_QCOM_SMD_RPM
>  	tristate
> diff --git a/drivers/interconnect/qcom/Makefile b/drivers/interconnect/qcom/Makefile
> index 67dafb7..0f5e88d 100644
> --- a/drivers/interconnect/qcom/Makefile
> +++ b/drivers/interconnect/qcom/Makefile
> @@ -3,7 +3,11 @@
>  qnoc-qcs404-objs			:= qcs404.o
>  qnoc-sdm845-objs			:= sdm845.o
>  icc-smd-rpm-objs			:= smd-rpm.o
> +bcm-voter-objs				:= bcm-voter.o

Maybe icc-bcm-voter-objs. Does the BCM vote for stuff other than bandwidth?

> +icc-rpmh-obj				:= icc-rpmh.o
>  
>  obj-$(CONFIG_INTERCONNECT_QCOM_QCS404) += qnoc-qcs404.o
>  obj-$(CONFIG_INTERCONNECT_QCOM_SDM845) += qnoc-sdm845.o
>  obj-$(CONFIG_INTERCONNECT_QCOM_SMD_RPM) += icc-smd-rpm.o
> +obj-$(CONFIG_INTERCONNECT_QCOM_BCM_VOTER) += bcm-voter.o
> +obj-$(CONFIG_INTERCONNECT_QCOM_RPMH) += icc-rpmh.o
> diff --git a/drivers/interconnect/qcom/bcm-voter.c b/drivers/interconnect/qcom/bcm-voter.c
> new file mode 100644
> index 0000000..f74ae5f
> --- /dev/null
> +++ b/drivers/interconnect/qcom/bcm-voter.c
[..]
> +/**
> + * of_bcm_voter_get - gets a bcm voter handle from DT node
> + * @dev: device pointer for the consumer device
> + * @name: name for the bcm voter device
> + *
> + * This function will match a device_node pointer for the phandle
> + * specified in the device DT and return a bcm_voter handle on success.
> + *
> + * Returns bcm_voter pointer or ERR_PTR() on error. EPROBE_DEFER is returned
> + * when matching bcm voter is yet to be found.
> + */
> +struct bcm_voter *of_bcm_voter_get(struct device *dev, const char *name)
> +{
> +	struct bcm_voter *voter = ERR_PTR(-EPROBE_DEFER);
> +	struct bcm_voter *temp;
> +	struct device_node *np, *node;
> +	int idx = 0;
> +
> +	if (!dev || !dev->of_node)
> +		return ERR_PTR(-ENODEV);
> +
> +	np = dev->of_node;
> +
> +	if (name) {
> +		idx = of_property_match_string(np, "qcom,bcm-voter-names", name);
> +		if (idx < 0)
> +			return ERR_PTR(idx);
> +	}
> +
> +	node = of_parse_phandle(np, "qcom,bcm-voters", idx);
> +
> +	list_for_each_entry(temp, &bcm_voters, voter_node) {
> +		if (temp->np == node)
> +			voter = temp;
> +			break;

Missing curly braces!

> +	}
> +
> +	return voter;
> +}
> +EXPORT_SYMBOL_GPL(of_bcm_voter_get);
> +
[..]
> +++ b/drivers/interconnect/qcom/bcm-voter.h
> @@ -0,0 +1,28 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2019, The Linux Foundation. All rights reserved.
> + *
> + */
> +
> +#ifndef __DRIVERS_INTERCONNECT_QCOM_ICC_BCM_VOTER_H__
> +#define __DRIVERS_INTERCONNECT_QCOM_ICC_BCM_VOTER_H__

Doesn't match the path - icc-bcm-voter.h vs bcm-voter.h?

> +
> +#include <soc/qcom/cmd-db.h>
> +#include <soc/qcom/rpmh.h>
> +#include <soc/qcom/tcs.h>
> +
> +#include "icc-rpmh.h"
> +
> +#define DEFINE_QBCM(_name, _bcmname, _keepalive, _numnodes, ...)	\
> +		static struct qcom_icc_bcm _name = {			\
> +		.name = _bcmname,					\
> +		.keepalive = _keepalive,				\
> +		.num_nodes = _numnodes,					\
> +		.nodes = { __VA_ARGS__ },				\
> +	}
> +
> +struct bcm_voter *of_bcm_voter_get(struct device *dev, const char *name);
> +void qcom_icc_bcm_voter_add(struct bcm_voter *voter, struct qcom_icc_bcm *bcm);
> +int qcom_icc_bcm_voter_commit(struct bcm_voter *voter);
> +
> +#endif
> diff --git a/drivers/interconnect/qcom/icc-rpmh.c b/drivers/interconnect/qcom/icc-rpmh.c
> new file mode 100644
> index 0000000..abe9f1e
> --- /dev/null
> +++ b/drivers/interconnect/qcom/icc-rpmh.c
> @@ -0,0 +1,154 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2019, The Linux Foundation. All rights reserved.
> + *
> + */
> +
> +#include <asm/div64.h>
> +#include <dt-bindings/interconnect/qcom,sdm845.h>
> +#include <linux/interconnect.h>
> +#include <linux/interconnect-provider.h>
> +
> +#include "icc-rpmh.h"
> +#include "bcm-voter.h"
> +
> +/**
> + * qcom_icc_pre_aggregate - cleans up stale values from prior icc_set
> + * @node: icc node to operate on
> + */
> +void qcom_icc_pre_aggregate(struct icc_node *node)
> +{
> +	size_t i;
> +	struct qcom_icc_node *qn;
> +
> +	qn = node->data;
> +
> +	for (i = 0; i < QCOM_ICC_NUM_BUCKETS; i++) {
> +		qn->sum_avg[i] = 0;
> +		qn->max_peak[i] = 0;
> +	}
> +}
> +EXPORT_SYMBOL_GPL(qcom_icc_pre_aggregate);
> +
> +/**
> + * qcom_icc_aggregate - aggregate bw for buckets indicated by tag
> + * @node: node to aggregate
> + * @tag: tag to indicate which buckets to aggregate
> + * @avg_bw: new bw to sum aggregate
> + * @peak_bw: new bw to max aggregate
> + * @agg_avg: existing aggregate avg bw val
> + * @agg_peak: existing aggregate peak bw val
> + */
> +int qcom_icc_aggregate(struct icc_node *node, u32 tag, u32 avg_bw,
> +		       u32 peak_bw, u32 *agg_avg, u32 *agg_peak)

Nit: Please match the open parenthesis.

> +{
> +	size_t i;
> +	struct qcom_icc_node *qn;
> +	struct qcom_icc_provider *qp;
> +
> +	qn = node->data;
> +	qp = to_qcom_provider(node->provider);
> +
> +	if (!tag)
> +		tag = QCOM_ICC_TAG_ALWAYS;
> +
> +	for (i = 0; i < QCOM_ICC_NUM_BUCKETS; i++) {
> +		if (tag & BIT(i)) {
> +			qn->sum_avg[i] += avg_bw;
> +			qn->max_peak[i] = max_t(u32, qn->max_peak[i], peak_bw);
> +		}
> +	}
> +
> +	*agg_avg += avg_bw;
> +	*agg_peak = max_t(u32, *agg_peak, peak_bw);
> +
> +	for (i = 0; i < qn->num_bcms; i++)
> +		qcom_icc_bcm_voter_add(qp->voter, qn->bcms[i]);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(qcom_icc_aggregate);
> +
> +/**
> + * qcom_icc_set - set the constraints based on path
> + * @src: source node for the path to set constraints on
> + * @dst: destination node for the path to set constraints on
> + *
> + * Return: 0 on success, or an error code otherwise
> + */
> +int qcom_icc_set(struct icc_node *src, struct icc_node *dst)
> +{
> +	struct qcom_icc_provider *qp;
> +	struct icc_node *node;
> +	int ret = 0;
> +
> +	if (!src)
> +		pr_err("src(%d)\n", 0);
> +	else
> +		pr_err("src(%d)\n", src->id);

pr_err?

> +
> +	if (!src)
> +		node = dst;
> +	else
> +		node = src;
> +
> +	qp = to_qcom_provider(node->provider);
> +
> +	qcom_icc_bcm_voter_commit(qp->voter);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(qcom_icc_set);
[..]
> +++ b/drivers/interconnect/qcom/icc-rpmh.h
> @@ -0,0 +1,150 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2019, The Linux Foundation. All rights reserved.
> + *
> + */
> +
> +#ifndef __DRIVERS_INTERCONNECT_QCOM_ICC_RPMH_H__
> +#define __DRIVERS_INTERCONNECT_QCOM_ICC_RPMH_H__
> +
> +#define to_qcom_provider(_provider) \
> +	container_of(_provider, struct qcom_icc_provider, provider)
> +
> +/**
> + * struct qcom_icc_provider - Qualcomm specific interconnect provider
> + * @dev: reference to the NoC device
> + * @bcms: list of bcms that maps to the provider
> + * @num_bcms: number of @bcms
> + * @voter: bcm voter targeted by this provider
> + */
> +struct qcom_icc_provider {
> +	struct icc_provider provider;
> +	struct device *dev;
> +	struct qcom_icc_bcm **bcms;
> +	size_t num_bcms;
> +	struct bcm_voter *voter;
> +};
> +
> +/**
> + * struct bcm_db - Auxiliary data pertaining to each Bus Clock Manager (BCM)
> + * @unit: divisor used to convert bytes/sec bw value to an RPMh msg
> + * @width: multiplier used to convert bytes/sec bw value to an RPMh msg
> + * @vcd: virtual clock domain that this bcm belongs to
> + * @reserved: reserved field
> + */
> +struct bcm_db {
> +	__le32 unit;
> +	__le16 width;
> +	u8 vcd;
> +	u8 reserved;
> +};

The same also exists in clk-rpmh.c. Should we move it to some common place?

> +
> +#define MAX_LINKS		128
> +#define MAX_BCMS		64
> +#define MAX_BCM_PER_NODE	3
> +#define MAX_VCD			10
> +
> +/*
> + * The AMC bucket denotes constraints that are applied to hardware when
> + * icc_set_bw() completes, whereas the WAKE and SLEEP constraints are applied
> + * when the execution environment transitions between active and low power mode.
> + */
> +#define QCOM_ICC_BUCKET_AMC		0
> +#define QCOM_ICC_BUCKET_WAKE		1
> +#define QCOM_ICC_BUCKET_SLEEP		2
> +#define QCOM_ICC_NUM_BUCKETS		3
> +#define QCOM_ICC_TAG_AMC		BIT(QCOM_ICC_BUCKET_AMC)
> +#define QCOM_ICC_TAG_WAKE		BIT(QCOM_ICC_BUCKET_WAKE)
> +#define QCOM_ICC_TAG_SLEEP		BIT(QCOM_ICC_BUCKET_SLEEP)
> +#define QCOM_ICC_TAG_ACTIVE_ONLY	(QCOM_ICC_TAG_AMC | QCOM_ICC_TAG_WAKE)
> +#define QCOM_ICC_TAG_ALWAYS		(QCOM_ICC_TAG_AMC | QCOM_ICC_TAG_WAKE |\
> +					 QCOM_ICC_TAG_SLEEP)
> +
> +/**
> + * struct qcom_icc_node - Qualcomm specific interconnect nodes
> + * @name: the node name used in debugfs
> + * @links: an array of nodes where we can go next while traversing
> + * @id: a unique node identifier
> + * @num_links: the total number of @links
> + * @channels: num of channels at this node
> + * @buswidth: width of the interconnect between a node and the bus
> + * @sum_avg: current sum aggregate value of all avg bw requests
> + * @max_peak: current max aggregate value of all peak bw requests
> + * @bcms: list of bcms associated with this logical node
> + * @num_bcms: num of @bcms
> + */
> +struct qcom_icc_node {
> +	const char *name;
> +	u16 links[MAX_LINKS];
> +	u16 id;
> +	u16 num_links;
> +	u16 channels;
> +	u16 buswidth;
> +	u64 sum_avg[QCOM_ICC_NUM_BUCKETS];
> +	u64 max_peak[QCOM_ICC_NUM_BUCKETS];
> +	struct qcom_icc_bcm *bcms[MAX_BCM_PER_NODE];
> +	size_t num_bcms;
> +};
> +
> +/**
> + * struct qcom_icc_bcm - Qualcomm specific hardware accelerator nodes
> + * known as Bus Clock Manager (BCM)
> + * @name: the bcm node name used to fetch BCM data from command db
> + * @type: latency or bandwidth bcm
> + * @addr: address offsets used when voting to RPMH
> + * @vote_x: aggregated threshold values, represents sum_bw when @type is bw bcm
> + * @vote_y: aggregated threshold values, represents peak_bw when @type is bw bcm
> + * @dirty: flag used to indicate whether the bcm needs to be committed
> + * @keepalive: flag used to indicate whether a keepalive is required
> + * @aux_data: auxiliary data used when calculating threshold values and
> + * communicating with RPMh
> + * @list: used to link to other bcms when compiling lists for commit
> + * @ws_list: used to keep track of bcms that may transition between wake/sleep
> + * @num_nodes: total number of @num_nodes
> + * @nodes: list of qcom_icc_nodes that this BCM encapsulates
> + */
> +struct qcom_icc_bcm {
> +	const char *name;
> +	u32 type;
> +	u32 addr;
> +	u64 vote_x[QCOM_ICC_NUM_BUCKETS];
> +	u64 vote_y[QCOM_ICC_NUM_BUCKETS];
> +	bool dirty;
> +	bool keepalive;
> +	struct bcm_db aux_data;
> +	struct list_head list;
> +	struct list_head ws_list;
> +	size_t num_nodes;
> +	struct qcom_icc_node *nodes[];
> +};
> +
> +struct qcom_icc_fabric {
> +	struct qcom_icc_node **nodes;
> +	size_t num_nodes;
> +};

Is this used?

> +
> +struct qcom_icc_desc {
> +	struct qcom_icc_node **nodes;
> +	size_t num_nodes;
> +	struct qcom_icc_bcm **bcms;
> +	size_t num_bcms;
> +};
> +
> +#define DEFINE_QNODE(_name, _id, _channels, _buswidth,			\
> +			_numlinks, ...)					\
> +		static struct qcom_icc_node _name = {			\
> +		.id = _id,						\
> +		.name = #_name,						\
> +		.channels = _channels,					\
> +		.buswidth = _buswidth,					\
> +		.num_links = _numlinks,					\
> +		.links = { __VA_ARGS__ },				\
> +	}
> +
> +int qcom_icc_aggregate(struct icc_node *node, u32 tag, u32 avg_bw,
> +			      u32 peak_bw, u32 *agg_avg, u32 *agg_peak);
> +int qcom_icc_set(struct icc_node *src, struct icc_node *dst);
> +int qcom_icc_bcm_init(struct qcom_icc_bcm *bcm, struct device *dev);
> +void qcom_icc_pre_aggregate(struct icc_node *node);
> +
> +#endif

Thanks for working on this!

BR,
Georgi