Re: [Patch 1/2] UefiCpuPkg: Add comments for PCDs definition.

["Kinney, Michael D" <michael.d.kinney@intel.com>]

Eric,

For the PCD PcdCpuProcTraceOutputScheme, the description of "Invalid scheme"
does not seem like a good description for disable.

Do we really need the value 0x02 for PcdCpuProcTraceOutputScheme at all?
Can we use PcdCpuFeaturesSetting set to 0x10 ProcTraceMemDisable
to know that the feature is disabled, and only look at 
PcdCpuProcTraceOutputScheme if PcdCpuFeaturesSetting is set to a value
where the memory size is > 0?

Also, when looking at where these PCD values are used in
UefiCpuPkg\Library\CpuCommonFeaturesLib\ProcTrace.c, I see use of BITxx
to modify the MSR_IA32_RTIT_CTL values.  Please use the bit fields in
the MSR_IA32_RTIT_CTL_REGISTER structure instead.  You can work on this
change as a separate patch.

Thanks,

Mike


> -----Original Message-----
> From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On
> Behalf Of Eric Dong
> Sent: Monday, August 14, 2017 12:23 AM
> To: edk2-devel@lists.01.org
> Cc: Ni, Ruiyu <ruiyu.ni@intel.com>; Kinney, Michael D
> <michael.d.kinney@intel.com>; Gao, Liming <liming.gao@intel.com>
> Subject: [edk2] [Patch 1/2] UefiCpuPkg: Add comments for PCDs
> definition.
> 
> Add valid/default values for PCD PcdCpuProcTraceMemSize and
> PcdCpuProcTraceOutputScheme in the comment part.
> 
> Cc: Liming Gao <liming.gao@intel.com>
> Cc: Ruiyu Ni <ruiyu.ni@intel.com>
> Cc: Michael D Kinney <michael.d.kinney@intel.com>
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Eric Dong <eric.dong@intel.com>
> ---
>  UefiCpuPkg/UefiCpuPkg.dec | 28 ++++++++++++++++++++++++++--
>  1 file changed, 26 insertions(+), 2 deletions(-)
> 
> diff --git a/UefiCpuPkg/UefiCpuPkg.dec
> b/UefiCpuPkg/UefiCpuPkg.dec
> index 2ddeab4..b4e099d 100644
> --- a/UefiCpuPkg/UefiCpuPkg.dec
> +++ b/UefiCpuPkg/UefiCpuPkg.dec
> @@ -285,12 +285,36 @@
>    # @ValidList   0x80000001 | 0
>    gUefiCpuPkgTokenSpaceGuid.PcdCpuFeaturesSetting|{0x00, 0x00,
> 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}|VOID*|0x00000019
> 
> -  ## Contains the size of memory required when CPU processor
> trace is enabled.
> +  ## Contains the size of memory required when CPU processor
> trace is enabled.<BR><BR>
> +  #  Default value is 0x10 which disables the processor
> trace.<BR>
> +  #  0x0  -  4K.<BR>
> +  #  0x1  -  8K.<BR>
> +  #  0x2  -  16K.<BR>
> +  #  0x3  -  32K.<BR>
> +  #  0x4  -  64K.<BR>
> +  #  0x5  -  128K.<BR>
> +  #  0x6  -  256K.<BR>
> +  #  0x7  -  512K.<BR>
> +  #  0x8  -  1M.<BR>
> +  #  0x9  -  2M.<BR>
> +  #  0xA  -  4M.<BR>
> +  #  0xB  -  8M.<BR>
> +  #  0xC  -  16M.<BR>
> +  #  0xD  -  32M.<BR>
> +  #  0xE  -  64M.<BR>
> +  #  0xF  -  128M.<BR>
> +  #  0x10 -  ProcTraceMemDisable.<BR>
>    # @Prompt The memory size used for processor trace.
> +  # @ValidRange  0x80000001 | 0 - 0x10
> 
> gUefiCpuPkgTokenSpaceGuid.PcdCpuProcTraceMemSize|0x10|UINT32|0x6
> 0000012
> 
> -  ## Contains the processor trace output scheme when CPU
> processor trace is enabled.
> +  ## Contains the processor trace output scheme when CPU
> processor trace is enabled.<BR><BR>
> +  #  Default value is 2 which disables the processor trace.<BR>
> +  #  0 - Single Range output scheme.<BR>
> +  #  1 - ToPA(Table of physical address) scheme.<BR>
> +  #  2 - Invalid scheme.<BR>
>    # @Prompt The processor trace output scheme.
> +  # @ValidRange  0x80000001 | 0 - 2
> 
> gUefiCpuPkgTokenSpaceGuid.PcdCpuProcTraceOutputScheme|0x2|UINT8|
> 0x60000015
> 
>  [UserExtensions.TianoCore."ExtraFiles"]
> --
> 2.7.0.windows.1
> 
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