Messages in this thread Patch in this message | | | Date | Thu, 15 Aug 2019 10:21:59 -0700 | From | "Luck, Tony" <> | Subject | Re: [PATCH] MAINTAINERS, x86/CPU: Tony Luck will maintain asm/intel-family.h |
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On Thu, Aug 15, 2019 at 09:58:22AM +0200, Borislav Petkov wrote: > On Wed, Aug 14, 2019 at 04:40:30PM -0700, Tony Luck wrote: > > There are a few different subsystems in the kernel that depend on > > model specific behaviour (perf, EDAC, power, ...). Easier for just > > one person to have the task to get new model numbers included instead > > of having these groups trip over each other to do it. > > > > Signed-off-by: Tony Luck <tony.luck@intel.com> > > --- > > MAINTAINERS | 6 ++++++ > > 1 file changed, 6 insertions(+) > > Applied, thanks. > > As a first order of business, pls sum up the naming scheme convention > you guys are going to adhere to so that it is clear to everybody: > > https://lkml.kernel.org/r/91eefbe4-e32b-d762-be4d-672ff915db47@intel.com > > in a patch form. :)
Like this?
From 364e337ec2008442a8a77cf919fbf499b297b3f4 Mon Sep 17 00:00:00 2001 From: Tony Luck <tony.luck@intel.com> Date: Thu, 15 Aug 2019 10:04:18 -0700 Subject: [PATCH] Documentation: x86: Explain Intel model naming convention
This was written in an e-mail by Dave Hansen, but not everybody reads the entire LKML archive before posting a patch.
https://lkml.kernel.org/r/91eefbe4-e32b-d762-be4d-672ff915db47@intel.com
Signed-off-by: Tony Luck <tony.luck@intel.com> --- Documentation/x86/index.rst | 1 + Documentation/x86/intel-cpu-models.rst | 37 ++++++++++++++++++++++++++ 2 files changed, 38 insertions(+) create mode 100644 Documentation/x86/intel-cpu-models.rst
diff --git a/Documentation/x86/index.rst b/Documentation/x86/index.rst index af64c4bb4447..6ba9e9cc5938 100644 --- a/Documentation/x86/index.rst +++ b/Documentation/x86/index.rst @@ -19,6 +19,7 @@ x86-specific Documentation tlb mtrr pat + intel-cpu-models intel_mpx intel-iommu intel_txt diff --git a/Documentation/x86/intel-cpu-models.rst b/Documentation/x86/intel-cpu-models.rst new file mode 100644 index 000000000000..75b5267a5354 --- /dev/null +++ b/Documentation/x86/intel-cpu-models.rst @@ -0,0 +1,37 @@ +.. SPDX-License-Identifier: GPL-2.0 + +======================= +Intel CPU model numbers +======================= + +The CPU model number on a running system can be found by executing +the CPUID(EAX=0) instruction to find the vendor, family, model +and stepping. The model number is found by concatenating two bit +fields from the EAX return value. Bits 19:16 (extended model number) +and 7:4 (model number). + +Inside the Linux kernel the vendor, family, model and stepping are +stored in the cpuinfo_x86 structure. Model specific code typically +uses x86_match_cpu() to determine if it is running on any of some +list of CPU models. + +There are several subsystems that need model specific handling on +Intel CPUs. For code legibility it is better to assign names for +the various model numbers in the include file <asm/intel-family.h> + +Currently all interesting Intel CPU models are in family 6. + +HOWTO Build an INTEL_FAM6_ definition: + +1. Start with INTEL_FAM6_ +2. If not Core-family, add a note about it, like "ATOM". There are only + two options for this (Xeon Phi and Atom). It is exceedingly unlikely + that you are adding a cpu which needs a new option here. +3. Add the processor microarchitecture, not the platform name +4. Add a short differentiator if necessary. Add an _X to differentiate + Server from Client. +5. Add an optional comment with the platform name(s) + +It should end up looking like this: + +INTEL_FAM6_<ATOM?>_<MICROARCH>_<SHORT...> /* Platform Name */ -- 2.20.1
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