Re: [RFC 03/10] platform/x86/intel/ifs: Add driver for In-Field Scan

["Raj, Ashok" <ashok.raj@intel.com>]

On Wed, Mar 02, 2022 at 03:24:47PM -0800, Dan Williams wrote:
> On Tue, 2022-03-01 at 11:54 -0800, Jithu Joseph wrote:
> > In-Field Scan (IFS) provides hardware hooks to perform core tests and
> > report failures for portions of silicon that lack error detection
> > capabilities, which will be available in some server SKUs starting with
> > Sapphire Rapids. It offers infrastructure to specific users such as cloud
> > providers or OEMs to schedule tests and find in-field failures due to aging
> > in silicon that might not necessarily be reported with normal machine
> > checks.
> >
> > Add basic parts of the IFS module (initialization and check IFS capability
> > support in a processor).
> >
> > MSR IA32_CORE_CAPABILITY is a feature-enumerating MSR, bit 2 of which
> > reports MSR_INTEGRITY_CAPABILITIES. Processor that supports IFS
> > should reports the MSR_INTEGRITY_CAPABILITIES enabled.
> >
> > Please check the latest Intel 64 and IA-32 Architectures Software
> > Developer's Manual for more detailed information on the MSR and the
> > MSR_INTEGRITY_CAPABILITIES.
> >
> > Originally-by: Kyung Min Park <kyung.min.park@intel.com>
> > Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
> > Reviewed-by: Ashok Raj <ashok.raj@intel.com>
> > Reviewed-by: Tony Luck <tony.luck@intel.com>
> > ---
> >  MAINTAINERS                             |  7 ++++
> >  drivers/platform/x86/intel/Kconfig      |  1 +
> >  drivers/platform/x86/intel/Makefile     |  1 +
> >  drivers/platform/x86/intel/ifs/Kconfig  |  9 +++++
> >  drivers/platform/x86/intel/ifs/Makefile |  7 ++++
> >  drivers/platform/x86/intel/ifs/core.c   | 49 +++++++++++++++++++++++++
> >  drivers/platform/x86/intel/ifs/ifs.h    | 14 +++++++
> >  7 files changed, 88 insertions(+)
> >  create mode 100644 drivers/platform/x86/intel/ifs/Kconfig
> >  create mode 100644 drivers/platform/x86/intel/ifs/Makefile
> >  create mode 100644 drivers/platform/x86/intel/ifs/core.c
> >  create mode 100644 drivers/platform/x86/intel/ifs/ifs.h
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 777cd6fa2b3d..4c9912c0d725 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -9685,6 +9685,13 @@ B:       https://bugzilla.kernel.org
> >  T:     git git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux.git
> >  F:     drivers/idle/intel_idle.c
> >
> > +INTEL IN FIELD SCAN (IFS) DRIVER
> > +M:     Jithu Joseph <jithu.joseph@intel.com>
> > +R:     Ashok Raj <ashok.raj@intel.com>
> > +R:     Tony Luck <tony.luck@intel.com>
> > +S:     Maintained
> > +F:     drivers/platform/x86/intel/ifs
> > +
> >  INTEL INTEGRATED SENSOR HUB DRIVER
> >  M:     Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
> >  M:     Jiri Kosina <jikos@kernel.org>
> > diff --git a/drivers/platform/x86/intel/Kconfig b/drivers/platform/x86/intel/Kconfig
> > index 8e65086bb6c8..7339e7daf0a1 100644
> > --- a/drivers/platform/x86/intel/Kconfig
> > +++ b/drivers/platform/x86/intel/Kconfig
> > @@ -4,6 +4,7 @@
> >  #
> >
> >  source "drivers/platform/x86/intel/atomisp2/Kconfig"
> > +source "drivers/platform/x86/intel/ifs/Kconfig"
> >  source "drivers/platform/x86/intel/int1092/Kconfig"
> >  source "drivers/platform/x86/intel/int33fe/Kconfig"
> >  source "drivers/platform/x86/intel/int3472/Kconfig"
> > diff --git a/drivers/platform/x86/intel/Makefile b/drivers/platform/x86/intel/Makefile
> > index 35f2066578b2..bd7f2ef5e767 100644
> > --- a/drivers/platform/x86/intel/Makefile
> > +++ b/drivers/platform/x86/intel/Makefile
> > @@ -5,6 +5,7 @@
> >  #
> >
> >  obj-$(CONFIG_INTEL_ATOMISP2_PDX86)     += atomisp2/
> > +obj-$(CONFIG_INTEL_IFS)                        += ifs/
> >  obj-$(CONFIG_INTEL_SAR_INT1092)                += int1092/
> >  obj-$(CONFIG_INTEL_CHT_INT33FE)                += int33fe/
> >  obj-$(CONFIG_INTEL_SKL_INT3472)                += int3472/
> > diff --git a/drivers/platform/x86/intel/ifs/Kconfig b/drivers/platform/x86/intel/ifs/Kconfig
> > new file mode 100644
> > index 000000000000..88e3d4fa1759
> > --- /dev/null
> > +++ b/drivers/platform/x86/intel/ifs/Kconfig
> > @@ -0,0 +1,9 @@
> > +config INTEL_IFS
> > +       tristate "Intel In Field Scan"
> > +       depends on X86 && 64BIT && SMP
> 
> Are there actual CONFIG_SMP and CONFIG_64BIT compilation dependencies
> in this driver? It looks like this could compile without those config
> dependencies.

Don't think this is anything specific to compile dependencies. 

This is a server feature and only targetted and validated in those configs,
untested and unsupported in 32bit configs.