Hi Mike,
Thanks for your suggestion.
After discussion with Eric, I know there is a function named
IsCpuFeatureSupported() to do the feature valid/invalid check.
User should do IsCpuFeatureSupported() check first and then
RegisterCpuFeature().
So there is no need to add any code to do the same work, I will roll back the
patch which has been checked in before.
Best Regards,
Bell Song
> -----Original Message-----
> From: Kinney, Michael D
> Sent: Tuesday, December 19, 2017 7:21 AM
> To: Song, BinX <binx.s...@intel.com>; edk2-devel@lists.01.org; Kinney,
> Michael D <michael.d.kin...@intel.com>
> Cc: Dong, Eric <eric.d...@intel.com>; ler...@redhat.com; Ni, Ruiyu
> <ruiyu...@intel.com>
> Subject: RE: [PATCH V2] UefiCpuPkg: Keep library class header file definition
> independent
>
> This still does not work because a library instance that
> registers a new CPU feature may want to use a new feature
> bit larger than MAX. This change moves the define
> from the RegisterCpuFeaturesLib library class to the
> implementation of the RegisterCpuFeaturesLibs.
>
> The components that know the maximum bit number are the
> NULL lib instances that register CPU features (e.g.
> CpuCommonFeaturesLib) and the platform developer that
> that provides the set of NULL lib instances in a platform
> DSC file and the associated PCDs. For example, the
> following DSC fragment only specifies a single NULL lib
> instance that registers CPU features. However, it is
> legal to provide additional NULL lib instances from
> Si packages.
>
> UefiCpuPkg/CpuFeatures/CpuFeaturesDxe.inf {
> <LibraryClasses>
>
> NULL|UefiCpuPkg/Library/CpuCommonFeaturesLib/CpuCommonFeaturesLib
> .inf
> }
>
> The maximum size of the bitmask for CPU features is known
> by the size of the PCD called PcdCpuFeaturesSupport that
> has a DEC default value based on CpuCommonFeaturesLib but
> can be set to a larger size based on the maximum bit used
> by all the NULL lib instances.
>
> So maybe the valid check should just verify that the bit
> number passed in is < PcdGetSize (PcdCpuFeaturesSupport) * 8.
> This eliminates the use of the #define value and uses an
> existing PCD.
>
> Thanks,
>
> Mike
>
> > -----Original Message-----
> > From: Song, BinX
> > Sent: Sunday, December 17, 2017 9:37 PM
> > To: edk2-devel@lists.01.org
> > Cc: Dong, Eric <eric.d...@intel.com>;
> > ler...@redhat.com; Ni, Ruiyu <ruiyu...@intel.com>;
> > Kinney, Michael D <michael.d.kin...@intel.com>
> > Subject: [PATCH V2] UefiCpuPkg: Keep library class
> > header file definition independent
> >
> > V2:
> > Move CPU_FEATURE_MAX definition from header file to C
> > file.
> > V1:
> > Keep library class header file definition independent
> >
> > Cc: Eric Dong <eric.d...@intel.com>
> > Cc: Laszlo Ersek <ler...@redhat.com>
> > Contributed-under: TianoCore Contribution Agreement 1.1
> > Signed-off-by: Bell Song <binx.s...@intel.com>
> > ---
> > UefiCpuPkg/Include/Library/RegisterCpuFeaturesLib.h
> > | 5 -----
> >
> > .../Library/RegisterCpuFeaturesLib/RegisterCpuFeaturesL
> > ib.c | 11 ++++++-----
> > 2 files changed, 6 insertions(+), 10 deletions(-)
> >
> > diff --git
> > a/UefiCpuPkg/Include/Library/RegisterCpuFeaturesLib.h
> > b/UefiCpuPkg/Include/Library/RegisterCpuFeaturesLib.h
> > index fc3ccda..9331e49 100644
> > ---
> > a/UefiCpuPkg/Include/Library/RegisterCpuFeaturesLib.h
> > +++
> > b/UefiCpuPkg/Include/Library/RegisterCpuFeaturesLib.h
> > @@ -71,11 +71,6 @@
> > #define CPU_FEATURE_APIC_TPR_UPDATE_MESSAGE
> > (32+9)
> > #define CPU_FEATURE_ENERGY_PERFORMANCE_BIAS
> > (32+10)
> > #define CPU_FEATURE_PPIN
> > (32+11)
> > -//
> > -// Currently, CPU_FEATURE_PROC_TRACE is the MAX
> > feature we support.
> > -// If you define a feature bigger than it, please also
> > replace it
> > -// in RegisterCpuFeatureLibIsFeatureValid function.
> > -//
> > #define CPU_FEATURE_PROC_TRACE
> > (32+12)
> >
> > #define CPU_FEATURE_BEFORE_ALL
> > BIT27
> > diff --git
> > a/UefiCpuPkg/Library/RegisterCpuFeaturesLib/RegisterCpu
> > FeaturesLib.c
> > b/UefiCpuPkg/Library/RegisterCpuFeaturesLib/RegisterCpu
> > FeaturesLib.c
> > index 6ec26e1..afc424c 100644
> > ---
> > a/UefiCpuPkg/Library/RegisterCpuFeaturesLib/RegisterCpu
> > FeaturesLib.c
> > +++
> > b/UefiCpuPkg/Library/RegisterCpuFeaturesLib/RegisterCpu
> > FeaturesLib.c
> > @@ -13,6 +13,10 @@
> > **/
> >
> > #include "RegisterCpuFeatures.h"
> > +//
> > +// Please keep CPU_FEATURE_MAX as the max CPU feature
> > +//
> > +#define CPU_FEATURE_MAX (32+12)
> >
> > /**
> > Checks if two CPU feature bit masks are equal.
> > @@ -97,11 +101,8 @@ RegisterCpuFeatureLibIsFeatureValid
> > (
> >
> > Data = Feature;
> > Data &= ~(CPU_FEATURE_BEFORE | CPU_FEATURE_AFTER |
> > CPU_FEATURE_BEFORE_ALL | CPU_FEATURE_AFTER_ALL);
> > - //
> > - // Currently, CPU_FEATURE_PROC_TRACE is the MAX
> > feature we support.
> > - // If you define a feature bigger than it, please
> > replace it at below.
> > - //
> > - if (Data > CPU_FEATURE_PROC_TRACE) {
> > +
> > + if (Data > CPU_FEATURE_MAX) {
> > DEBUG ((DEBUG_ERROR, "Invalid CPU feature: 0x%x ",
> > Feature));
> > return FALSE;
> > }
> > --
> > 2.10.2.windows.1
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