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Message-ID: <ebd7e310-d1b4-4b2e-a915-6241e04763d4@arm.com>
Date: Mon, 18 Dec 2023 10:46:18 +0000
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MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH v3 6/8] coresight-tpdm: Add timestamp control register
 support for the CMB
Content-Language: en-GB
To: Tao Zhang <quic_taozha@quicinc.com>,
 Mathieu Poirier <mathieu.poirier@linaro.org>,
 Alexander Shishkin <alexander.shishkin@linux.intel.com>,
 Konrad Dybcio <konradybcio@gmail.com>, Mike Leach <mike.leach@linaro.org>,
 Rob Herring <robh+dt@kernel.org>,
 Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
Cc: Jinlong Mao <quic_jinlmao@quicinc.com>, Leo Yan <leo.yan@linaro.org>,
 Greg Kroah-Hartman <gregkh@linuxfoundation.org>, coresight@lists.linaro.org,
 linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
 devicetree@vger.kernel.org, Tingwei Zhang <quic_tingweiz@quicinc.com>,
 Yuanfang Zhang <quic_yuanfang@quicinc.com>,
 Trilok Soni <quic_tsoni@quicinc.com>, Song Chai <quic_songchai@quicinc.com>,
 linux-arm-msm@vger.kernel.org, andersson@kernel.org
References: <1700533494-19276-1-git-send-email-quic_taozha@quicinc.com>
 <1700533494-19276-7-git-send-email-quic_taozha@quicinc.com>
From: Suzuki K Poulose <suzuki.poulose@arm.com>
In-Reply-To: <1700533494-19276-7-git-send-email-quic_taozha@quicinc.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit

On 21/11/2023 02:24, Tao Zhang wrote:
> CMB_TIER register is CMB subunit timestamp insertion enable register.
> Bit 0 is PATT_TSENAB bit. Set this bit to 1 to request a timestamp
> following a CMB interface pattern match. Bit 1 is XTRIG_TSENAB bit.
> Set this bit to 1 to request a timestamp following a CMB CTI timestamp
> request. Bit 2 is TS_ALL bit. Set this bit to 1 to request timestamp
> for all packets.
> 
> Reviewed-by: James Clark <james.clark@arm.com>
> Signed-off-by: Tao Zhang <quic_taozha@quicinc.com>
> Signed-off-by: Jinlong Mao <quic_jinlmao@quicinc.com>
> ---
>   .../testing/sysfs-bus-coresight-devices-tpdm  |  35 ++++++
>   drivers/hwtracing/coresight/coresight-tpdm.c  | 116 +++++++++++++++++-
>   drivers/hwtracing/coresight/coresight-tpdm.h  |  14 +++
>   3 files changed, 162 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
> index 53662ce7c2d0..e0b77107be13 100644
> --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
> +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
> @@ -214,3 +214,38 @@ KernelVersion	6.7
>   Contact:	Jinlong Mao (QUIC) <quic_jinlmao@quicinc.com>, Tao Zhang (QUIC) <quic_taozha@quicinc.com>
>   Description:
>   		(RW) Set/Get the mask of the pattern for the CMB subunit TPDM.
> +
> +What:		/sys/bus/coresight/devices/<tpdm-name>/cmb_patt/enable_ts
> +Date:		September 2023
> +KernelVersion	6.7
> +Contact:	Jinlong Mao (QUIC) <quic_jinlmao@quicinc.com>, Tao Zhang (QUIC) <quic_taozha@quicinc.com>
> +Description:
> +		(Write) Set the pattern timestamp of CMB tpdm. Read
> +		the pattern timestamp of CMB tpdm.
> +
> +		Accepts only one of the 2 values -  0 or 1.
> +		0 : Disable CMB pattern timestamp.
> +		1 : Enable CMB pattern timestamp.
> +
> +What:		/sys/bus/coresight/devices/<tpdm-name>/cmb_trig_ts
> +Date:		September 2023
> +KernelVersion	6.7
> +Contact:	Jinlong Mao (QUIC) <quic_jinlmao@quicinc.com>, Tao Zhang (QUIC) <quic_taozha@quicinc.com>
> +Description:
> +		(RW) Set/Get the trigger timestamp of the CMB for tpdm.
> +
> +		Accepts only one of the 2 values -  0 or 1.
> +		0 : Set the CMB trigger type to false
> +		1 : Set the CMB trigger type to true
> +
> +What:		/sys/bus/coresight/devices/<tpdm-name>/cmb_ts_all
> +Date:		September 2023
> +KernelVersion	6.7
> +Contact:	Jinlong Mao (QUIC) <quic_jinlmao@quicinc.com>, Tao Zhang (QUIC) <quic_taozha@quicinc.com>
> +Description:
> +		(RW) Read or write the status of timestamp upon all interface.
> +		Only value 0 and 1  can be written to this node. Set this node to 1 to requeset
> +		timestamp to all trace packet.
> +		Accepts only one of the 2 values -  0 or 1.
> +		0 : Disable the timestamp of all trace packets.
> +		1 : Enable the timestamp of all trace packets.
> diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
> index 894d4309f1c7..f6cda5616e84 100644
> --- a/drivers/hwtracing/coresight/coresight-tpdm.c
> +++ b/drivers/hwtracing/coresight/coresight-tpdm.c
> @@ -331,6 +331,36 @@ static void tpdm_enable_dsb(struct tpdm_drvdata *drvdata)
>   	writel_relaxed(val, drvdata->base + TPDM_DSB_CR);
>   }
>   
> +static void set_cmb_tier(struct tpdm_drvdata *drvdata)
> +{
> +	u32 val;
> +
> +	val = readl_relaxed(drvdata->base + TPDM_CMB_TIER);
> +
> +	/* Clear all relevant fields */
> +	val &= ~(TPDM_CMB_TIER_PATT_TSENAB | TPDM_CMB_TIER_TS_ALL |
> +		 TPDM_CMB_TIER_XTRIG_TSENAB);
> +
> +	/* Set pattern timestamp type and enablement */
> +	if (drvdata->cmb->patt_ts)
> +		val |= TPDM_CMB_TIER_PATT_TSENAB;

  -- cut --
> +	else
> +		val &= ~TPDM_CMB_TIER_PATT_TSENAB;


All the else cases in this function are superfluous. Please remove all
of them.

> +
> +	/* Set trigger timestamp */
> +	if (drvdata->cmb->trig_ts)
> +		val |= TPDM_CMB_TIER_XTRIG_TSENAB;
> +	else
> +		val &= ~TPDM_CMB_TIER_XTRIG_TSENAB;
> +
> +	/* Set all timestamp enablement*/
> +	if (drvdata->cmb->ts_all)
> +		val |= TPDM_CMB_TIER_TS_ALL;
> +	else
> +		val &= ~TPDM_CMB_TIER_TS_ALL;
> +	writel_relaxed(val, drvdata->base + TPDM_CMB_TIER);
> +}
> +
>   static void tpdm_enable_cmb(struct tpdm_drvdata *drvdata)
>   {
>   	u32 val, i;
> @@ -347,6 +377,8 @@ static void tpdm_enable_cmb(struct tpdm_drvdata *drvdata)
>   			    drvdata->base + TPDM_CMB_XPMR(i));
>   	}
>   
> +	set_cmb_tier(drvdata);
> +
>   	val = readl_relaxed(drvdata->base + TPDM_CMB_CR);
>   	/*
>   	 * Set to 0 for continuous CMB collection mode,
> @@ -695,9 +727,17 @@ static ssize_t enable_ts_show(struct device *dev,
>   			      char *buf)
>   {
>   	struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
> +	ssize_t size = 0;
>   
> -	return sysfs_emit(buf, "%u\n",
> -			 (unsigned int)drvdata->dsb->patt_ts);
> +	if (tpdm_has_dsb_dataset(drvdata))
> +		size = sysfs_emit(buf, "%u\n",
> +				 (unsigned int)drvdata->dsb->patt_ts);
> +
> +	if (tpdm_has_cmb_dataset(drvdata))
> +		size = sysfs_emit(buf, "%u\n",
> +				 (unsigned int)drvdata->cmb->patt_ts);

Why does this need to show two values ? This must only show ONE value.
How you deduce that might be based on the availability of the feature
set. Or store the TS value in the drvdata and use that instead for
controlling CMB/DSB.

Also, the sysfs documentation needs update, if this is going to
control the CMB.

Suzuki


> +
> +	return size;
>   }
>   
>   /*
> @@ -715,8 +755,13 @@ static ssize_t enable_ts_store(struct device *dev,
>   		return -EINVAL;
>   
>   	spin_lock(&drvdata->spinlock);
> -	drvdata->dsb->patt_ts = !!val;
> +	if (tpdm_has_dsb_dataset(drvdata))
> +		drvdata->dsb->patt_ts = !!val;
> +
> +	if (tpdm_has_cmb_dataset(drvdata))
> +		drvdata->cmb->patt_ts = !!val;
>   	spin_unlock(&drvdata->spinlock);
> +
>   	return size;
>   }
>   static DEVICE_ATTR_RW(enable_ts);
> @@ -851,6 +896,68 @@ static ssize_t cmb_mode_store(struct device *dev,
>   }
>   static DEVICE_ATTR_RW(cmb_mode);
>   
> +static ssize_t cmb_ts_all_show(struct device *dev,
> +			       struct device_attribute *attr,
> +			       char *buf)
> +{
> +	struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
> +
> +	return sysfs_emit(buf, "%u\n",
> +			  (unsigned int)drvdata->cmb->ts_all);
> +}
> +
> +static ssize_t cmb_ts_all_store(struct device *dev,
> +				struct device_attribute *attr,
> +				const char *buf,
> +				size_t size)
> +{
> +	struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
> +	unsigned long val;
> +
> +	if ((kstrtoul(buf, 0, &val)) || (val & ~1UL))
> +		return -EINVAL;
> +
> +	spin_lock(&drvdata->spinlock);
> +	if (val)
> +		drvdata->cmb->ts_all = true;
> +	else
> +		drvdata->cmb->ts_all = false;
> +	spin_unlock(&drvdata->spinlock);
> +	return size;
> +}
> +static DEVICE_ATTR_RW(cmb_ts_all);
> +
> +static ssize_t cmb_trig_ts_show(struct device *dev,
> +				struct device_attribute *attr,
> +				char *buf)
> +{
> +	struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
> +
> +	return sysfs_emit(buf, "%u\n",
> +			  (unsigned int)drvdata->cmb->trig_ts);
> +}
> +
> +static ssize_t cmb_trig_ts_store(struct device *dev,
> +				 struct device_attribute *attr,
> +				 const char *buf,
> +				 size_t size)
> +{
> +	struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
> +	unsigned long val;
> +
> +	if ((kstrtoul(buf, 0, &val)) || (val & ~1UL))
> +		return -EINVAL;
> +
> +	spin_lock(&drvdata->spinlock);
> +	if (val)
> +		drvdata->cmb->trig_ts = true;
> +	else
> +		drvdata->cmb->trig_ts = false;
> +	spin_unlock(&drvdata->spinlock);
> +	return size;
> +}
> +static DEVICE_ATTR_RW(cmb_trig_ts);
> +
>   static struct attribute *tpdm_dsb_edge_attrs[] = {
>   	&dev_attr_ctrl_idx.attr,
>   	&dev_attr_ctrl_val.attr,
> @@ -973,6 +1080,7 @@ static struct attribute *tpdm_cmb_patt_attrs[] = {
>   	CMB_PATT_ATTR(1),
>   	CMB_PATT_MASK_ATTR(0),
>   	CMB_PATT_MASK_ATTR(1),
> +	&dev_attr_enable_ts.attr,
>   	NULL,
>   };
>   
> @@ -985,6 +1093,8 @@ static struct attribute *tpdm_dsb_attrs[] = {
>   
>   static struct attribute *tpdm_cmb_attrs[] = {
>   	&dev_attr_cmb_mode.attr,
> +	&dev_attr_cmb_ts_all.attr,
> +	&dev_attr_cmb_trig_ts.attr,
>   	NULL,
>   };
>   
> diff --git a/drivers/hwtracing/coresight/coresight-tpdm.h b/drivers/hwtracing/coresight/coresight-tpdm.h
> index e90d008c1cb2..65b7ca6c4077 100644
> --- a/drivers/hwtracing/coresight/coresight-tpdm.h
> +++ b/drivers/hwtracing/coresight/coresight-tpdm.h
> @@ -11,6 +11,8 @@
>   
>   /* CMB Subunit Registers */
>   #define TPDM_CMB_CR		(0xA00)
> +/*CMB subunit timestamp insertion enable register*/
> +#define TPDM_CMB_TIER		(0xA04)
>   /*CMB subunit timestamp pattern registers*/
>   #define TPDM_CMB_TPR(n)		(0xA08 + (n * 4))
>   /*CMB subunit timestamp pattern mask registers*/
> @@ -24,6 +26,12 @@
>   #define TPDM_CMB_CR_ENA		BIT(0)
>   /* Trace collection mode for CMB subunit */
>   #define TPDM_CMB_CR_MODE	BIT(1)
> +/* Timestamp control for pattern match */
> +#define TPDM_CMB_TIER_PATT_TSENAB	BIT(0)
> +/* CMB CTI timestamp request */
> +#define TPDM_CMB_TIER_XTRIG_TSENAB	BIT(1)
> +/* For timestamp fo all trace */
> +#define TPDM_CMB_TIER_TS_ALL		BIT(2)
>   
>   /*Patten register number*/
>   #define TPDM_CMB_MAX_PATT		2
> @@ -217,6 +225,9 @@ struct dsb_dataset {
>    * @patt_mask:        Save value for pattern mask
>    * @trig_patt:        Save value for trigger pattern
>    * @trig_patt_mask:   Save value for trigger pattern mask
> + * @patt_ts:          Indicates if pattern match for timestamp is enabled.
> + * @trig_ts:          Indicates if CTI trigger for timestamp is enabled.
> + * @ts_all:           Indicates if timestamp is enabled for all packets.
>    */
>   struct cmb_dataset {
>   	u32			trace_mode;
> @@ -224,6 +235,9 @@ struct cmb_dataset {
>   	u32			patt_mask[TPDM_CMB_MAX_PATT];
>   	u32			trig_patt[TPDM_CMB_MAX_PATT];
>   	u32			trig_patt_mask[TPDM_CMB_MAX_PATT];
> +	bool			patt_ts;
> +	bool			trig_ts;
> +	bool			ts_all;
>   };
>   
>   /**