Message-ID: <ae24703de33d4049c451dd4a331f7a5f@codeaurora.org>
Date:   Fri, 06 Sep 2019 18:21:54 +0530
From:   ppvk@...eaurora.org
To:     adrian.hunter@...el.com, ulf.hansson@...aro.org,
        robh+dt@...nel.org, georgi.djakov@...aro.org
Cc:     asutoshd@...eaurora.org, vbadigan@...eaurora.org,
        stummala@...eaurora.org, sayalil@...eaurora.org,
        rampraka@...eaurora.org, linux-mmc@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-arm-msm@...r.kernel.org,
        devicetree@...r.kernel.org,
        Subhash Jadavani <subhashj@...eaurora.org>,
        Andy Gross <agross@...nel.org>
Subject: Re: [RFC 1/2] mmc: sdhci-msm: Add support for bus bandwidth voting

+Georgi Djakov

On 2019-09-06 18:17, Pradeep P V K wrote:
> Vote for the MSM bus bandwidth required by SDHC driver
> based on the clock frequency and bus width of the card.
> Otherwise,the system clocks may run at minimum clock speed
> and thus affecting the performance.
> 
> This change is based on Georgi Djakov [RFC]
> (https://lkml.org/lkml/2018/10/11/499)
> 
> Signed-off-by: Sahitya Tummala <stummala@...eaurora.org>
> Signed-off-by: Subhash Jadavani <subhashj@...eaurora.org>
> Signed-off-by: Veerabhadrarao Badiganti <vbadigan@...eaurora.org>
> Signed-off-by: Pradeep P V K <ppvk@...eaurora.org>
> ---
>  drivers/mmc/host/sdhci-msm.c | 393 
> ++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 390 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-msm.c 
> b/drivers/mmc/host/sdhci-msm.c
> index b75c82d..71515ca 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -11,6 +11,7 @@
>  #include <linux/mmc/mmc.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/slab.h>
> +#include <linux/interconnect.h>
>  #include <linux/iopoll.h>
>  #include <linux/regulator/consumer.h>
> 
> @@ -122,6 +123,9 @@
>  #define msm_host_writel(msm_host, val, host, offset) \
>  	msm_host->var_ops->msm_writel_relaxed(val, host, offset)
> 
> +#define SDHC_DDR "sdhc-ddr"
> +#define CPU_SDHC "cpu-sdhc"
> +
>  struct sdhci_msm_offset {
>  	u32 core_hc_mode;
>  	u32 core_mci_data_cnt;
> @@ -228,6 +232,31 @@ struct sdhci_msm_variant_info {
>  	const struct sdhci_msm_offset *offset;
>  };
> 
> +struct msm_bus_vectors {
> +	uint64_t ab;
> +	uint64_t ib;
> +};
> +
> +struct msm_bus_path {
> +	unsigned int num_paths;
> +	struct msm_bus_vectors *vec;
> +};
> +
> +struct sdhci_msm_bus_vote_data {
> +	const char *name;
> +	unsigned int num_usecase;
> +	struct msm_bus_path *usecase;
> +
> +	unsigned int *bw_vecs;
> +	unsigned int bw_vecs_size;
> +
> +	struct icc_path *sdhc_ddr;
> +	struct icc_path *cpu_sdhc;
> +
> +	uint32_t curr_vote;
> +
> +};
> +
>  struct sdhci_msm_host {
>  	struct platform_device *pdev;
>  	void __iomem *core_mem;	/* MSM SDCC mapped address */
> @@ -253,8 +282,13 @@ struct sdhci_msm_host {
>  	const struct sdhci_msm_offset *offset;
>  	bool use_cdr;
>  	u32 transfer_mode;
> +	bool skip_bus_bw_voting;
> +	struct sdhci_msm_bus_vote_data *bus_vote_data;
> +	struct delayed_work bus_vote_work;
>  };
> 
> +static void sdhci_msm_bus_voting(struct sdhci_host *host, u32 enable);
> +
>  static const struct sdhci_msm_offset *sdhci_priv_msm_offset(struct
> sdhci_host *host)
>  {
>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> @@ -1557,6 +1591,8 @@ static void sdhci_msm_set_clock(struct
> sdhci_host *host, unsigned int clock)
> 
>  	msm_set_clock_rate_for_bus_mode(host, clock);
>  out:
> +	if (!msm_host->skip_bus_bw_voting)
> +		sdhci_msm_bus_voting(host, !!clock);
>  	__sdhci_msm_set_clock(host, clock);
>  }
> 
> @@ -1678,6 +1714,341 @@ static void
> sdhci_msm_set_regulator_caps(struct sdhci_msm_host *msm_host)
>  	pr_debug("%s: supported caps: 0x%08x\n", mmc_hostname(mmc), caps);
>  }
> 
> +static int sdhci_msm_dt_get_array(struct device *dev, const char 
> *prop_name,
> +				 u32 **bw_vecs, int *len, u32 size)
> +{
> +	int ret = 0;
> +	struct device_node *np = dev->of_node;
> +	size_t sz;
> +	u32 *arr = NULL;
> +
> +	if (!of_get_property(np, prop_name, len)) {
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +	sz = *len = *len / sizeof(*arr);
> +	if (sz <= 0 || (size > 0 && (sz > size))) {
> +		dev_err(dev, "%s invalid size\n", prop_name);
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	arr = devm_kzalloc(dev, sz * sizeof(*arr), GFP_KERNEL);
> +	if (!arr) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +
> +	ret = of_property_read_u32_array(np, prop_name, arr, sz);
> +	if (ret < 0) {
> +		dev_err(dev, "%s failed reading array %d\n", prop_name, ret);
> +		goto out;
> +	}
> +	*bw_vecs = arr;
> +out:
> +	if (ret)
> +		*len = 0;
> +	return ret;
> +}
> +
> +/* Returns required bandwidth in Bytes per Sec */
> +static unsigned long sdhci_get_bw_required(struct sdhci_host *host,
> +					struct mmc_ios *ios)
> +{
> +	unsigned long bw;
> +	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
> +
> +	bw = msm_host->clk_rate;
> +
> +	if (ios->bus_width == MMC_BUS_WIDTH_4)
> +		bw /= 2;
> +	else if (ios->bus_width == MMC_BUS_WIDTH_1)
> +		bw /= 8;
> +
> +	return bw;
> +}
> +
> +static int sdhci_msm_bus_get_vote_for_bw(struct sdhci_msm_host *host,
> +					   unsigned int bw)
> +{
> +	struct sdhci_msm_bus_vote_data *bvd = host->bus_vote_data;
> +
> +	unsigned int *table = bvd->bw_vecs;
> +	unsigned int size = bvd->bw_vecs_size;
> +	int i;
> +
> +	for (i = 0; i < size; i++) {
> +		if (bw <= table[i])
> +			break;
> +	}
> +
> +	if (i && (i == size))
> +		i--;
> +
> +	return i;
> +}
> +
> +/*
> + * This function must be called with host lock acquired.
> + * Caller of this function should also ensure that msm bus client
> + * handle is not null.
> + */
> +static inline int sdhci_msm_bus_set_vote(struct sdhci_msm_host 
> *msm_host,
> +					     int vote,
> +					     unsigned long *flags)
> +{
> +	struct sdhci_host *host =  platform_get_drvdata(msm_host->pdev);
> +	struct sdhci_msm_bus_vote_data *bvd = msm_host->bus_vote_data;
> +	struct msm_bus_path *usecase = bvd->usecase;
> +	struct msm_bus_vectors *vec = usecase[vote].vec;
> +	int ddr_rc = 0, cpu_rc = 0;
> +
> +	if (vote != bvd->curr_vote) {
> +		spin_unlock_irqrestore(&host->lock, *flags);
> +		pr_debug("%s: vote:%d sdhc_ddr ab:%llu ib:%llu cpu_sdhc ab:%llu 
> ib:%llu\n",
> +				mmc_hostname(host->mmc), vote, vec[0].ab,
> +				vec[0].ib, vec[1].ab, vec[1].ib);
> +		ddr_rc = icc_set_bw(bvd->sdhc_ddr, vec[0].ab, vec[0].ib);
> +		cpu_rc = icc_set_bw(bvd->cpu_sdhc, vec[1].ab, vec[1].ib);
> +		spin_lock_irqsave(&host->lock, *flags);
> +		if (ddr_rc || cpu_rc) {
> +			pr_err("%s: icc_set() failed\n",
> +				mmc_hostname(host->mmc));
> +			goto out;
> +		}
> +		bvd->curr_vote = vote;
> +	}
> +out:
> +	return cpu_rc;
> +}
> +
> +/*
> + * Internal work. Work to set 0 bandwidth for msm bus.
> + */
> +static void sdhci_msm_bus_work(struct work_struct *work)
> +{
> +	struct sdhci_msm_host *msm_host;
> +	struct sdhci_host *host;
> +	unsigned long flags;
> +
> +	msm_host = container_of(work, struct sdhci_msm_host,
> +				bus_vote_work.work);
> +	host =  platform_get_drvdata(msm_host->pdev);
> +
> +	/* Check handle and return */
> +	if (!msm_host->bus_vote_data->sdhc_ddr ||
> +			!msm_host->bus_vote_data->cpu_sdhc)
> +		return;
> +	spin_lock_irqsave(&host->lock, flags);
> +	/* don't vote for 0 bandwidth if any request is in progress */
> +	if (!host->mmc->ongoing_mrq)
> +		sdhci_msm_bus_set_vote(msm_host, 0, &flags);
> +	else
> +		pr_warn("Transfer in progress.Skipping bus voting to 0\n");
> +	spin_unlock_irqrestore(&host->lock, flags);
> +}
> +
> +/*
> + * This function cancels any scheduled delayed work and sets the bus
> + * vote based on bw (bandwidth) argument.
> + */
> +static void sdhci_msm_bus_cancel_work_and_set_vote(struct sdhci_host 
> *host,
> +						unsigned int bw)
> +{
> +	int vote;
> +	unsigned long flags;
> +	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
> +
> +	cancel_delayed_work_sync(&msm_host->bus_vote_work);
> +	spin_lock_irqsave(&host->lock, flags);
> +	vote = sdhci_msm_bus_get_vote_for_bw(msm_host, bw);
> +	sdhci_msm_bus_set_vote(msm_host, vote, &flags);
> +	spin_unlock_irqrestore(&host->lock, flags);
> +}
> +
> +
> +#define MSM_MMC_BUS_VOTING_DELAY	200 /* msecs */
> +#define VOTE_ZERO  0
> +
> +/* This function queues a work which will set the bandwidth requiement 
> to 0 */
> +static void sdhci_msm_bus_queue_work(struct sdhci_host *host)
> +{
> +	unsigned long flags;
> +	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
> +
> +	spin_lock_irqsave(&host->lock, flags);
> +	if (msm_host->bus_vote_data->curr_vote != VOTE_ZERO)
> +		queue_delayed_work(system_wq,
> +				   &msm_host->bus_vote_work,
> +				   msecs_to_jiffies(MSM_MMC_BUS_VOTING_DELAY));
> +	spin_unlock_irqrestore(&host->lock, flags);
> +}
> +
> +static struct sdhci_msm_bus_vote_data
> *sdhci_msm_get_bus_vote_data(struct device
> +				       *dev, struct sdhci_msm_host *host)
> +
> +{
> +	struct platform_device *pdev = to_platform_device(dev);
> +	struct device_node *of_node = dev->of_node;
> +	struct sdhci_msm_bus_vote_data *bvd = NULL;
> +	struct msm_bus_path *usecase = NULL;
> +	int ret = 0, i = 0, j, k, num_paths, len;
> +	const uint32_t *vec_arr = NULL;
> +	bool mem_err = false;
> +
> +	if (!pdev) {
> +		dev_err(dev, "Null platform device!\n");
> +		return NULL;
> +	}
> +
> +	bvd = devm_kzalloc(dev, sizeof(struct sdhci_msm_bus_vote_data),
> +				GFP_KERNEL);
> +	if (!bvd) {
> +		ret = -ENOMEM;
> +		dev_err(dev, "No sufficient memory!\n");
> +		return bvd;
> +	}
> +	ret = sdhci_msm_dt_get_array(dev, "qcom,bus-bw-vectors-bps",
> +				&bvd->bw_vecs, &bvd->bw_vecs_size, 0);
> +	if (ret) {
> +		dev_info(dev, "No dt property of bus bw. voting defined!\n");
> +		dev_info(dev, "Skipping Bus BW voting now!!\n");
> +		host->skip_bus_bw_voting = true;
> +		if (ret != -EINVAL && ret != -ENOMEM)
> +			goto free;
> +		goto err;
> +	}
> +
> +	ret = of_property_read_string(of_node, "qcom,msm-bus,name", 
> &bvd->name);
> +	if (ret) {
> +		dev_err(dev, "Error: (%d) Bus name missing!\n", ret);
> +		goto err;
> +	}
> +
> +	ret = of_property_read_u32(of_node, "qcom,msm-bus,num-cases",
> +		&bvd->num_usecase);
> +	if (ret) {
> +		dev_err(dev, "Error: num-usecases not found\n");
> +		goto err;
> +	}
> +
> +	usecase = devm_kzalloc(dev, (sizeof(struct msm_bus_path) *
> +				   bvd->num_usecase), GFP_KERNEL);
> +	if (!usecase)
> +		goto err;
> +
> +	ret = of_property_read_u32(of_node, "qcom,msm-bus,num-paths",
> +				   &num_paths);
> +	if (ret) {
> +		dev_err(dev, "Error: num_paths not found\n");
> +		goto out;
> +	}
> +
> +	vec_arr = of_get_property(of_node, "qcom,msm-bus,vectors-KBps", 
> &len);
> +	if (vec_arr == NULL) {
> +		dev_err(dev, "Error: Vector array not found\n");
> +		goto out;
> +	}
> +
> +	for (i = 0; i < bvd->num_usecase; i++) {
> +		usecase[i].num_paths = num_paths;
> +		usecase[i].vec = devm_kzalloc(dev, num_paths *
> +					      sizeof(struct msm_bus_vectors),
> +					      GFP_KERNEL);
> +		if (!usecase[i].vec) {
> +			mem_err = true;
> +			dev_err(dev, "Error: Failed to alloc mem for vectors\n");
> +			goto out;
> +		}
> +		for (j = 0; j < num_paths; j++) {
> +			int idx = ((i * num_paths) + j) * 2;
> +
> +			usecase[i].vec[j].ab = (uint64_t)
> +				be32_to_cpu(vec_arr[idx]);
> +			usecase[i].vec[j].ib = (uint64_t)
> +				be32_to_cpu(vec_arr[idx + 1]);
> +		}
> +	}
> +
> +	bvd->usecase = usecase;
> +	return bvd;
> +out:
> +	if (mem_err) {
> +		for (k = i - 1; k >= 0; k--)
> +			devm_kfree(dev, usecase[k].vec);
> +	}
> +	devm_kfree(dev, usecase);
> +free:
> +	devm_kfree(dev, bvd->bw_vecs);
> +err:
> +	devm_kfree(dev, bvd);
> +	bvd = NULL;
> +	return bvd;
> +}
> +
> +static int sdhci_msm_bus_register(struct sdhci_msm_host *host,
> +				struct platform_device *pdev)
> +{
> +	struct sdhci_msm_bus_vote_data *bsd;
> +	struct device *dev = &pdev->dev;
> +
> +	bsd = sdhci_msm_get_bus_vote_data(dev, host);
> +	if (!bsd) {
> +		dev_err(&pdev->dev, "Failed: getting bus_scale data\n");
> +		return PTR_ERR(bsd);
> +	}
> +	host->bus_vote_data = bsd;
> +
> +	bsd->sdhc_ddr = of_icc_get(&pdev->dev, SDHC_DDR);
> +	if (IS_ERR(bsd->sdhc_ddr)) {
> +		dev_err(&pdev->dev, "Error: (%ld) failed getting %s path\n",
> +			PTR_ERR(bsd->sdhc_ddr), SDHC_DDR);
> +		return PTR_ERR(bsd->sdhc_ddr);
> +	}
> +
> +	bsd->cpu_sdhc = of_icc_get(&pdev->dev, CPU_SDHC);
> +	if (IS_ERR(bsd->cpu_sdhc)) {
> +		dev_err(&pdev->dev, "Error: (%ld) failed getting %s path\n",
> +			PTR_ERR(bsd->cpu_sdhc), CPU_SDHC);
> +		return PTR_ERR(bsd->cpu_sdhc);
> +	}
> +
> +	INIT_DELAYED_WORK(&host->bus_vote_work, sdhci_msm_bus_work);
> +
> +	return 0;
> +}
> +
> +static void sdhci_msm_bus_unregister(struct device *dev,
> +				struct sdhci_msm_host *host)
> +{
> +	struct sdhci_msm_bus_vote_data *bsd = host->bus_vote_data;
> +	int i;
> +
> +	icc_put(bsd->sdhc_ddr);
> +	icc_put(bsd->cpu_sdhc);
> +
> +	for (i = 0; i < bsd->num_usecase; i++)
> +		devm_kfree(dev, bsd->usecase[i].vec);
> +	devm_kfree(dev, bsd->usecase);
> +	devm_kfree(dev, bsd->bw_vecs);
> +	devm_kfree(dev, bsd);
> +}
> +
> +static void sdhci_msm_bus_voting(struct sdhci_host *host, u32 enable)
> +{
> +	struct mmc_ios *ios = &host->mmc->ios;
> +	unsigned int bw;
> +
> +	bw = sdhci_get_bw_required(host, ios);
> +	if (enable)
> +		sdhci_msm_bus_cancel_work_and_set_vote(host, bw);
> +	else
> +		sdhci_msm_bus_queue_work(host);
> +}
> +
>  static const struct sdhci_msm_variant_ops mci_var_ops = {
>  	.msm_readl_relaxed = sdhci_msm_mci_variant_readl_relaxed,
>  	.msm_writel_relaxed = sdhci_msm_mci_variant_writel_relaxed,
> @@ -1839,6 +2210,13 @@ static int sdhci_msm_probe(struct 
> platform_device *pdev)
>  		dev_warn(&pdev->dev, "TCXO clk not present (%d)\n", ret);
>  	}
> 
> +	ret = sdhci_msm_bus_register(msm_host, pdev);
> +	if (ret && !msm_host->skip_bus_bw_voting)
> +		goto clk_disable;
> +
> +	if (!msm_host->skip_bus_bw_voting)
> +		sdhci_msm_bus_voting(host, 1);
> +
>  	if (!msm_host->mci_removed) {
>  		core_memres = platform_get_resource(pdev, IORESOURCE_MEM, 1);
>  		msm_host->core_mem = devm_ioremap_resource(&pdev->dev,
> @@ -1846,7 +2224,7 @@ static int sdhci_msm_probe(struct platform_device 
> *pdev)
> 
>  		if (IS_ERR(msm_host->core_mem)) {
>  			ret = PTR_ERR(msm_host->core_mem);
> -			goto clk_disable;
> +			goto bus_unregister;
>  		}
>  	}
> 
> @@ -1918,7 +2296,7 @@ static int sdhci_msm_probe(struct platform_device 
> *pdev)
>  	msm_host->pwr_irq = platform_get_irq_byname(pdev, "pwr_irq");
>  	if (msm_host->pwr_irq < 0) {
>  		ret = msm_host->pwr_irq;
> -		goto clk_disable;
> +		goto bus_unregister;
>  	}
> 
>  	sdhci_msm_init_pwr_irq_wait(msm_host);
> @@ -1931,7 +2309,7 @@ static int sdhci_msm_probe(struct platform_device 
> *pdev)
>  					dev_name(&pdev->dev), host);
>  	if (ret) {
>  		dev_err(&pdev->dev, "Request IRQ failed (%d)\n", ret);
> -		goto clk_disable;
> +		goto bus_unregister;
>  	}
> 
>  	pm_runtime_get_noresume(&pdev->dev);
> @@ -1956,6 +2334,11 @@ static int sdhci_msm_probe(struct 
> platform_device *pdev)
>  	pm_runtime_disable(&pdev->dev);
>  	pm_runtime_set_suspended(&pdev->dev);
>  	pm_runtime_put_noidle(&pdev->dev);
> +bus_unregister:
> +	if (!msm_host->skip_bus_bw_voting) {
> +		sdhci_msm_bus_cancel_work_and_set_vote(host, 0);
> +		sdhci_msm_bus_unregister(&pdev->dev, msm_host);
> +	}
>  clk_disable:
>  	clk_bulk_disable_unprepare(ARRAY_SIZE(msm_host->bulk_clks),
>  				   msm_host->bulk_clks);
> @@ -1985,6 +2368,10 @@ static int sdhci_msm_remove(struct 
> platform_device *pdev)
>  				   msm_host->bulk_clks);
>  	if (!IS_ERR(msm_host->bus_clk))
>  		clk_disable_unprepare(msm_host->bus_clk);
> +	if (!msm_host->skip_bus_bw_voting) {
> +		sdhci_msm_bus_cancel_work_and_set_vote(host, 0);
> +		sdhci_msm_bus_unregister(&pdev->dev, msm_host);
> +	}
>  	sdhci_pltfm_free(pdev);
>  	return 0;
>  }

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