Re: [edk2-devel] [Patch 1/4] UefiCpuPkg/RegisterCpuFeaturesLib: Add "detect before set" Micros.

["Laszlo Ersek" <lersek@redhat.com>]

On 08/12/19 09:46, Dong, Eric wrote:
> Hi Laszlo,
> 
>> -----Original Message-----
>> From: devel@edk2.groups.io [mailto:devel@edk2.groups.io] On Behalf Of
>> Laszlo Ersek
>> Sent: Friday, August 9, 2019 11:14 PM
>> To: Dong, Eric <eric.dong@intel.com>; devel@edk2.groups.io
>> Cc: Ni, Ray <ray.ni@intel.com>
>> Subject: Re: [edk2-devel] [Patch 1/4] UefiCpuPkg/RegisterCpuFeaturesLib:
>> Add "detect before set" Micros.
>>
>> On 08/09/19 08:11, Eric Dong wrote:
>>> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2040
>>>
>>> Add below new micros which test the current value before set the new
>>> value. Only set new value when current value not same as new value.
>>>   CPU_REGISTER_TABLE_TEST_THEN_WRITE32
>>>   CPU_REGISTER_TABLE_TEST_THEN_WRITE64
>>>   CPU_REGISTER_TABLE_TEST_THEN_WRITE_FIELD
>>>
>>> Signed-off-by: Eric Dong <eric.dong@intel.com>
>>> Cc: Ray Ni <ray.ni@intel.com>
>>> Cc: Laszlo Ersek <lersek@redhat.com>
>>> ---
>>>  UefiCpuPkg/Include/AcpiCpuData.h              |  1 +
>>>  .../Include/Library/RegisterCpuFeaturesLib.h  | 77 +++++++++++++++++--
>>>  .../RegisterCpuFeaturesLib.c                  | 14 +++-
>>>  3 files changed, 80 insertions(+), 12 deletions(-)
>>
>> (1) When you format your patch sets, can you please use the following two
>> options:
>>
>>  --stat=1000 --stat-graph-width=20
>>
>> Otherwise the diffstats are truncated (on the left) and hard to understand.
>>
> 
> 1. I use TortoiseGit to create patch, do you know how to enable these setting in TortoiseGit?

Sorry, no clue :(

>  
>>>
>>> diff --git a/UefiCpuPkg/Include/AcpiCpuData.h
>>> b/UefiCpuPkg/Include/AcpiCpuData.h
>>> index b963a2f592..c764e209cf 100644
>>> --- a/UefiCpuPkg/Include/AcpiCpuData.h
>>> +++ b/UefiCpuPkg/Include/AcpiCpuData.h
>>> @@ -81,6 +81,7 @@ typedef struct {
>>>    UINT16         Reserved;              // offset 10 - 11
>>>    UINT32         HighIndex;             // offset 12-15, only valid for
>> MemoryMapped
>>>    UINT64         Value;                 // offset 16-23
>>> +  UINT8          DetectIt;              // 0ffset 24
>>>  } CPU_REGISTER_TABLE_ENTRY;
>>
>> (2) Another quite generic comment -- "DetectIt" does not look helpful.
>> Somehow the verb "detect" does not communicate the right action to me.
>>
>> How about using a more established name, such as:
>>
>> - CompareAndSwap
>> - CompareAndSet
>> - TestAndSet
>>
>> ?
>>
>> If you agree, then I suggest updating the parameter names, and their
>> comments too, below.
> 
> 2.  Yes, I change from "TestIt" to "DetectIt" because I think it's better. Seems like this is not a correct change. 
> I will use "TestThenWrite" as the new name which align our new macro " CPU_REGISTER_TABLE_TEST_THEN_WRITE****". What do you think?

Sounds good, thanks.

Laszlo