Re: [PATCH v3 1/7] coresight: Convert tag clear function to take a struct cs_access

[Suzuki K Poulose <suzuki.poulose@arm.com>]

On 21/03/2025 11:02, Suzuki K Poulose wrote:
> On 20/03/2025 14:34, James Clark wrote:
>> The self hosted claim tag will be reset on device probe in a later
>> commit. We'll want to do this before coresight_register() is called so
>> won't have a coresight_device and have to use cs_access instead.
>>
>> Also make them public and create locked and unlocked versions for
>> later use.
>>
>> These look functions look like they set the whole tags register as one
>> value, but they only set and clear the self hosted bit using a SET/CLR
>> bits mechanism so also rename the functions to reflect this better.
>>
>> Reviewed-by: Leo Yan <leo.yan@arm.com>
>> Signed-off-by: James Clark <james.clark@linaro.org>
>> ---
>>   drivers/hwtracing/coresight/coresight-core.c | 27 ++++++++++++++++++ 
>> +--------
>>   include/linux/coresight.h                    |  3 ++-
>>   2 files changed, 21 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/ 
>> hwtracing/coresight/coresight-core.c
>> index fb43ef6a3b1f..8471aefeac76 100644
>> --- a/drivers/hwtracing/coresight/coresight-core.c
>> +++ b/drivers/hwtracing/coresight/coresight-core.c
>> @@ -144,19 +144,30 @@ static inline bool 
>> coresight_is_claimed_any(struct coresight_device *csdev)
>>       return coresight_read_claim_tags(csdev) != 0;
>>   }
>> -static inline void coresight_set_claim_tags(struct coresight_device 
>> *csdev)
>> +static inline void coresight_set_self_claim_tag(struct 
>> coresight_device *csdev)
> 
> nit: For consistency, this should be renamed to _unlocked ?
> 

minor nit on the subject;

s/cs_access/csdev_access/

Suzuki


> 

Rest looks fine to me
> 
> Suzuki
> 
> 
>>   {
>>       csdev_access_relaxed_write32(&csdev->access, 
>> CORESIGHT_CLAIM_SELF_HOSTED,
>>                        CORESIGHT_CLAIMSET);
>>       isb();
>>   }
>> -static inline void coresight_clear_claim_tags(struct coresight_device 
>> *csdev)
>> +void coresight_clear_self_claim_tag(struct csdev_access *csa)
>>   {
>> -    csdev_access_relaxed_write32(&csdev->access, 
>> CORESIGHT_CLAIM_SELF_HOSTED,
>> +    if (csa->io_mem)
>> +        CS_UNLOCK(csa->base);
>> +    coresight_clear_self_claim_tag_unlocked(csa);
>> +    if (csa->io_mem)
>> +        CS_LOCK(csa->base);
>> +}
>> +EXPORT_SYMBOL_GPL(coresight_clear_self_claim_tag);
>> +
>> +void coresight_clear_self_claim_tag_unlocked(struct csdev_access *csa)
>> +{
>> +    csdev_access_relaxed_write32(csa, CORESIGHT_CLAIM_SELF_HOSTED,
>>                        CORESIGHT_CLAIMCLR);
>>       isb();
>>   }
>> +EXPORT_SYMBOL_GPL(coresight_clear_self_claim_tag_unlocked);
>>   /*
>>    * coresight_claim_device_unlocked : Claim the device for self- 
>> hosted usage
>> @@ -176,11 +187,11 @@ int coresight_claim_device_unlocked(struct 
>> coresight_device *csdev)
>>       if (coresight_is_claimed_any(csdev))
>>           return -EBUSY;
>> -    coresight_set_claim_tags(csdev);
>> +    coresight_set_self_claim_tag(csdev);
>>       if (coresight_is_claimed_self_hosted(csdev))
>>           return 0;
>> -    /* There was a race setting the tags, clean up and fail */
>> -    coresight_clear_claim_tags(csdev);
>> +    /* There was a race setting the tag, clean up and fail */
>> +    coresight_clear_self_claim_tag_unlocked(&csdev->access);
>>       return -EBUSY;
>>   }
>>   EXPORT_SYMBOL_GPL(coresight_claim_device_unlocked);
>> @@ -201,7 +212,7 @@ int coresight_claim_device(struct coresight_device 
>> *csdev)
>>   EXPORT_SYMBOL_GPL(coresight_claim_device);
>>   /*
>> - * coresight_disclaim_device_unlocked : Clear the claim tags for the 
>> device.
>> + * coresight_disclaim_device_unlocked : Clear the claim tag for the 
>> device.
>>    * Called with CS_UNLOCKed for the component.
>>    */
>>   void coresight_disclaim_device_unlocked(struct coresight_device *csdev)
>> @@ -211,7 +222,7 @@ void coresight_disclaim_device_unlocked(struct 
>> coresight_device *csdev)
>>           return;
>>       if (coresight_is_claimed_self_hosted(csdev))
>> -        coresight_clear_claim_tags(csdev);
>> +        coresight_clear_self_claim_tag_unlocked(&csdev->access);
>>       else
>>           /*
>>            * The external agent may have not honoured our claim
>> diff --git a/include/linux/coresight.h b/include/linux/coresight.h
>> index d79a242b271d..00134a80d358 100644
>> --- a/include/linux/coresight.h
>> +++ b/include/linux/coresight.h
>> @@ -685,7 +685,8 @@ extern int coresight_timeout_action(struct 
>> csdev_access *csa, u32 offset,
>>   extern int coresight_claim_device(struct coresight_device *csdev);
>>   extern int coresight_claim_device_unlocked(struct coresight_device 
>> *csdev);
>> -
>> +void coresight_clear_self_claim_tag(struct csdev_access *csa);
>> +void coresight_clear_self_claim_tag_unlocked(struct csdev_access *csa);
>>   extern void coresight_disclaim_device(struct coresight_device *csdev);
>>   extern void coresight_disclaim_device_unlocked(struct 
>> coresight_device *csdev);
>>   extern char *coresight_alloc_device_name(struct coresight_dev_list 
>> *devs,
>>
>