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Message-ID: <0d4e2aa7-23e3-4851-bc43-80e7737f3a1a@quicinc.com>
Date: Wed, 20 Dec 2023 16:56:42 +0800
From: Tao Zhang <quic_taozha@...cinc.com>
To: Suzuki K Poulose <suzuki.poulose@....com>,
Mathieu Poirier
<mathieu.poirier@...aro.org>,
Alexander Shishkin
<alexander.shishkin@...ux.intel.com>,
Konrad Dybcio <konradybcio@...il.com>,
Mike Leach <mike.leach@...aro.org>, Rob Herring <robh+dt@...nel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>
CC: Jinlong Mao <quic_jinlmao@...cinc.com>, Leo Yan <leo.yan@...aro.org>,
"Greg Kroah-Hartman" <gregkh@...uxfoundation.org>,
<coresight@...ts.linaro.org>, <linux-arm-kernel@...ts.infradead.org>,
<linux-kernel@...r.kernel.org>, <devicetree@...r.kernel.org>,
Tingwei Zhang
<quic_tingweiz@...cinc.com>,
Yuanfang Zhang <quic_yuanfang@...cinc.com>,
Trilok Soni <quic_tsoni@...cinc.com>,
Song Chai <quic_songchai@...cinc.com>, <linux-arm-msm@...r.kernel.org>,
<andersson@...nel.org>
Subject: Re: [PATCH v3 3/8] coresight-tpdm: Add CMB dataset support
On 12/19/2023 9:56 PM, Suzuki K Poulose wrote:
> On 19/12/2023 09:22, Tao Zhang wrote:
>>
>> On 12/18/2023 6:34 PM, Suzuki K Poulose wrote:
>>> On 21/11/2023 02:24, Tao Zhang wrote:
>>>> CMB (continuous multi-bit) is one of TPDM's dataset type. CMB subunit
>>>> can be enabled for data collection by writing 1 to the first bit of
>>>> CMB_CR register. This change is to add enable/disable function for
>>>> CMB dataset by writing CMB_CR register.
>>>>
>>>> Reviewed-by: James Clark <james.clark@....com>
>>>> Signed-off-by: Tao Zhang <quic_taozha@...cinc.com>
>>>> Signed-off-by: Jinlong Mao <quic_jinlmao@...cinc.com>
>>>> ---
>>>> drivers/hwtracing/coresight/coresight-tpdm.c | 31
>>>> ++++++++++++++++++++
>>>> drivers/hwtracing/coresight/coresight-tpdm.h | 8 +++++
>>>> 2 files changed, 39 insertions(+)
>>>>
>>>> diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c
>>>> b/drivers/hwtracing/coresight/coresight-tpdm.c
>>>> index 97654aa4b772..c8bb38822e08 100644
>>>> --- a/drivers/hwtracing/coresight/coresight-tpdm.c
>>>> +++ b/drivers/hwtracing/coresight/coresight-tpdm.c
>>>> @@ -131,6 +131,11 @@ static bool tpdm_has_dsb_dataset(struct
>>>> tpdm_drvdata *drvdata)
>>>> return (drvdata->datasets & TPDM_PIDR0_DS_DSB);
>>>> }
>>>> +static bool tpdm_has_cmb_dataset(struct tpdm_drvdata *drvdata)
>>>> +{
>>>> + return (drvdata->datasets & TPDM_PIDR0_DS_CMB);
>>>> +}
>>>> +
>>>> static umode_t tpdm_dsb_is_visible(struct kobject *kobj,
>>>> struct attribute *attr, int n)
>>>> {
>>>> @@ -267,6 +272,17 @@ static void tpdm_enable_dsb(struct
>>>> tpdm_drvdata *drvdata)
>>>> writel_relaxed(val, drvdata->base + TPDM_DSB_CR);
>>>> }
>>>> +static void tpdm_enable_cmb(struct tpdm_drvdata *drvdata)
>>>> +{
>>>> + u32 val;
>>>> +
>>>> + val = readl_relaxed(drvdata->base + TPDM_CMB_CR);
>>>> + val |= TPDM_CMB_CR_ENA;
>>>> +
>>>> + /* Set the enable bit of CMB control register to 1 */
>>>> + writel_relaxed(val, drvdata->base + TPDM_CMB_CR);
>>>> +}
>>>> +
>>>> /*
>>>> * TPDM enable operations
>>>> * The TPDM or Monitor serves as data collection component for
>>>> various
>>>> @@ -281,6 +297,8 @@ static void __tpdm_enable(struct tpdm_drvdata
>>>> *drvdata)
>>>> if (tpdm_has_dsb_dataset(drvdata))
>>>> tpdm_enable_dsb(drvdata);
>>>> + if (tpdm_has_cmb_dataset(drvdata))
>>>> + tpdm_enable_cmb(drvdata);
>>>
>>> Don't we need to add this check in the "property read" section ?
>>> Otherwise, we could generate warnings unnecessarily ?
>>>
>>> i.e, if (tpdm_has_cmb_..())
>>> rc |= fwnode_..read_property(cmb-elem-size...)
>>>
>>> Similarly for DSB.
>>
>> TPDM and TPDA are two independent hardware. If you want to modify
>> them in this way, the
>>
>
> You don't have to, as long as the header files are included ?
>
> Read my response in the other patch, where it applies.
Got it. I will update in the next patch series.
Best,
Tao
>
> Suzuki
>
>> two independent drivers will be coupled to each other. At the same
>> time, this configuration
>>
>> is manually set in the devicetree by the users, and this check cannot
>> avoid manual setting errors.
>>
>> Even if the configuration is wrong, it will not cause the driver to
>> stop working, it will only cause
>>
>> the data to be lost from the TPDM.
>>
>>>
>>>> CS_LOCK(drvdata->base);
>>>> }
>>>> @@ -314,6 +332,17 @@ static void tpdm_disable_dsb(struct
>>>> tpdm_drvdata *drvdata)
>>>> writel_relaxed(val, drvdata->base + TPDM_DSB_CR);
>>>> }
>>>> +static void tpdm_disable_cmb(struct tpdm_drvdata *drvdata)
>>>> +{
>>>> + u32 val;
>>>> +
>>>> + val = readl_relaxed(drvdata->base + TPDM_CMB_CR);
>>>> + val &= ~TPDM_CMB_CR_ENA;
>>>> +
>>>> + /* Set the enable bit of CMB control register to 0 */
>>>> + writel_relaxed(val, drvdata->base + TPDM_CMB_CR);
>>>> +}
>>>> +
>>>> /* TPDM disable operations */
>>>> static void __tpdm_disable(struct tpdm_drvdata *drvdata)
>>>> {
>>>> @@ -321,6 +350,8 @@ static void __tpdm_disable(struct tpdm_drvdata
>>>> *drvdata)
>>>> if (tpdm_has_dsb_dataset(drvdata))
>>>> tpdm_disable_dsb(drvdata);
>>>> + if (tpdm_has_cmb_dataset(drvdata))
>>>> + tpdm_disable_cmb(drvdata);
>>>
>>> minor nit: Instead of having these :
>>>
>>> if (tpdm_has_XY_()
>>> tpdm_{enable/disable}_XY_()
>>> I prefer :
>>>
>>> tpdm_{enable/disable}_XY_
>>>
>>> and the helper take care of returning early if the feature is
>>> not present.
>> Does the following sample modification meet your expectation?
>> static void tpdm_disable_dsb(struct tpdm_drvdata *drvdata)
>> {
>> u32 val;
>>
>> if (tpdm_has_dsb_dataset(drvdata)) {
>> /* Set the enable bit of DSB control register to 0 */
>> val = readl_relaxed(drvdata->base + TPDM_DSB_CR);
>> val &= ~TPDM_DSB_CR_ENA;
>> writel_relaxed(val, drvdata->base + TPDM_DSB_CR);
>> }
>> }
>>
>> static void tpdm_disable_cmb(struct tpdm_drvdata *drvdata)
>> {
>> u32 val;
>>
>> if (tpdm_has_cmb_dataset(drvdata)) {
>> val = readl_relaxed(drvdata->base + TPDM_CMB_CR);
>> val &= ~TPDM_CMB_CR_ENA;
>>
>> /* Set the enable bit of CMB control register to 0 */
>> writel_relaxed(val, drvdata->base + TPDM_CMB_CR);
>> }
>> }
>>
>> /* TPDM disable operations */
>> static void __tpdm_disable(struct tpdm_drvdata *drvdata)
>> {
>> CS_UNLOCK(drvdata->base);
>>
>> tpdm_disable_dsb(drvdata);
>> tpdm_disable_cmb(drvdata);
>>
>
> Yes, thats exactly I was looking for.
Got it. I will update in the next patch series.
Best,
Tao
>
>> CS_LOCK(drvdata->base);
>>
>> }
>>
>>
>> Best,
>>
>> Tao
>>
>>>
>>>
>>> Suzuki
>>>
>>>
>>>> CS_LOCK(drvdata->base);
>>>> }
>>>> diff --git a/drivers/hwtracing/coresight/coresight-tpdm.h
>>>> b/drivers/hwtracing/coresight/coresight-tpdm.h
>>>> index 4115b2a17b8d..0098c58dfdd6 100644
>>>> --- a/drivers/hwtracing/coresight/coresight-tpdm.h
>>>> +++ b/drivers/hwtracing/coresight/coresight-tpdm.h
>>>> @@ -9,6 +9,12 @@
>>>> /* The max number of the datasets that TPDM supports */
>>>> #define TPDM_DATASETS 7
>>>> +/* CMB Subunit Registers */
>>>> +#define TPDM_CMB_CR (0xA00)
>>>> +
>>>> +/* Enable bit for CMB subunit */
>>>> +#define TPDM_CMB_CR_ENA BIT(0)
>>>> +
>>>> /* DSB Subunit Registers */
>>>> #define TPDM_DSB_CR (0x780)
>>>> #define TPDM_DSB_TIER (0x784)
>>>> @@ -79,10 +85,12 @@
>>>> *
>>>> * PERIPHIDR0[0] : Fix to 1 if ImplDef subunit present, else 0
>>>> * PERIPHIDR0[1] : Fix to 1 if DSB subunit present, else 0
>>>> + * PERIPHIDR0[2] : Fix to 1 if CMB subunit present, else 0
>>>> */
>>>> #define TPDM_PIDR0_DS_IMPDEF BIT(0)
>>>> #define TPDM_PIDR0_DS_DSB BIT(1)
>>>> +#define TPDM_PIDR0_DS_CMB BIT(2)
>>>> #define TPDM_DSB_MAX_LINES 256
>>>> /* MAX number of EDCR registers */
>>>
>
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