Re: [PATCH v2] perf: add missing MODULE_DESCRIPTION() macros

[Jeff Johnson <quic_jjohnson@quicinc.com>]

On 7/1/2024 7:05 AM, Will Deacon wrote:
> On Thu, Jun 20, 2024 at 06:46:09PM -0700, Jeff Johnson wrote:
>> With ARCH=x86, make allmodconfig && make W=1 C=1 reports:
>> WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/perf/arm-ccn.o
>> WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/perf/fsl_imx8_ddr_perf.o
>> WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/perf/marvell_cn10k_ddr_pmu.o
>> WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/perf/arm_cspmu/arm_cspmu_module.o
>> WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/perf/arm_cspmu/nvidia_cspmu.o
>> WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/perf/arm_cspmu/ampere_cspmu.o
>> WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/perf/cxl_pmu.o
>>
>> Add the missing invocation of the MODULE_DESCRIPTION() macro to all
>> files which have a MODULE_LICENSE().
>>
>> This includes drivers/perf/hisilicon/hisi_uncore_pmu.c which, although
>> it did not produce a warning with the x86 allmodconfig configuration,
>> may cause this warning with arm64 configurations.
>>
>> Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
>> ---
>> Changes in v2:
>> - Updated hisi_uncore_pmu.c description per Yicong Yang
>> - Link to v1: https://lore.kernel.org/r/20240611-md-drivers-perf-v1-1-c001bae6da5c@quicinc.com
>> ---
>>  drivers/perf/arm-ccn.c                   | 1 +
>>  drivers/perf/arm_cspmu/ampere_cspmu.c    | 1 +
>>  drivers/perf/arm_cspmu/arm_cspmu.c       | 1 +
>>  drivers/perf/arm_cspmu/nvidia_cspmu.c    | 1 +
>>  drivers/perf/cxl_pmu.c                   | 1 +
>>  drivers/perf/fsl_imx8_ddr_perf.c         | 1 +
>>  drivers/perf/hisilicon/hisi_uncore_pmu.c | 1 +
>>  drivers/perf/marvell_cn10k_ddr_pmu.c     | 1 +
>>  8 files changed, 8 insertions(+)
>>
>> diff --git a/drivers/perf/arm-ccn.c b/drivers/perf/arm-ccn.c
>> index 86ef31ac7503..65f4882531db 100644
>> --- a/drivers/perf/arm-ccn.c
>> +++ b/drivers/perf/arm-ccn.c
>> @@ -1561,4 +1561,5 @@ module_init(arm_ccn_init);
>>  module_exit(arm_ccn_exit);
>>  
>>  MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
>> +MODULE_DESCRIPTION("ARM CCN (Cache Coherent Network) driver support");
>>  MODULE_LICENSE("GPL v2");
>> diff --git a/drivers/perf/arm_cspmu/ampere_cspmu.c b/drivers/perf/arm_cspmu/ampere_cspmu.c
>> index f146a455e838..426b3cfcb52e 100644
>> --- a/drivers/perf/arm_cspmu/ampere_cspmu.c
>> +++ b/drivers/perf/arm_cspmu/ampere_cspmu.c
>> @@ -269,4 +269,5 @@ static void __exit ampere_cspmu_exit(void)
>>  module_init(ampere_cspmu_init);
>>  module_exit(ampere_cspmu_exit);
>>  
>> +MODULE_DESCRIPTION("Ampere SoC PMU (Performance Monitor Unit) driver");
> 
> Curious: why do you expand the PMU acronym here, but not for any of the
> other drivers? If we're going to add these strings to all the drivers in
> one go, then it would good to be consistent.

Since I'm modifying hundreds of files treewide, I'm not spending much time on
individual files. In most cases I've taken these descriptions directly from
code comments, Kconfig descriptions, or git logs.

This description was derived from the prologue comment in ampere_cspmu.c (I
added "driver"):
/*
 * Ampere SoC PMU (Performance Monitor Unit)
 *
 * Copyright (c) 2023, Ampere Computing LLC
 */


> 
>>  MODULE_LICENSE("GPL");
>> diff --git a/drivers/perf/arm_cspmu/arm_cspmu.c b/drivers/perf/arm_cspmu/arm_cspmu.c
>> index c318dc909767..c21c564840d6 100644
>> --- a/drivers/perf/arm_cspmu/arm_cspmu.c
>> +++ b/drivers/perf/arm_cspmu/arm_cspmu.c
>> @@ -1427,4 +1427,5 @@ EXPORT_SYMBOL_GPL(arm_cspmu_impl_unregister);
>>  module_init(arm_cspmu_init);
>>  module_exit(arm_cspmu_exit);
>>  
>> +MODULE_DESCRIPTION("ARM CoreSight Architecture PMU driver");

compare to prologue for this file:
/*
 * ARM CoreSight Architecture PMU driver.
 *

>>  MODULE_LICENSE("GPL v2");
>> diff --git a/drivers/perf/arm_cspmu/nvidia_cspmu.c b/drivers/perf/arm_cspmu/nvidia_cspmu.c
>> index 5b84b701ad62..0dea47e48ac5 100644
>> --- a/drivers/perf/arm_cspmu/nvidia_cspmu.c
>> +++ b/drivers/perf/arm_cspmu/nvidia_cspmu.c
>> @@ -417,4 +417,5 @@ static void __exit nvidia_cspmu_exit(void)
>>  module_init(nvidia_cspmu_init);
>>  module_exit(nvidia_cspmu_exit);
>>  
>> +MODULE_DESCRIPTION("NVIDIA Coresight Architecture PMU driver");
>>  MODULE_LICENSE("GPL v2");
>> diff --git a/drivers/perf/cxl_pmu.c b/drivers/perf/cxl_pmu.c
>> index 1f93a66eff5b..8b6ce9ea5a55 100644
>> --- a/drivers/perf/cxl_pmu.c
>> +++ b/drivers/perf/cxl_pmu.c
>> @@ -972,6 +972,7 @@ static __exit void cxl_pmu_exit(void)
>>  	cpuhp_remove_multi_state(cxl_pmu_cpuhp_state_num);
>>  }
>>  
>> +MODULE_DESCRIPTION("CXL Performance Monitoring Unit driver");
> 
> Similarly here, we now have a conflicting expansion of the acronym.

I'll make them consistent in the MODULE_DESCRIPTION()s.
Do you have a preference for expanding or not expanding?

/jeff