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| author | Yazen Ghannam <yazen.ghannam@amd.com> | 2020-11-09 21:06:56 +0000 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-11-19 11:43:13 +0100 |
| commit | 028c221ed1904af9ac3c5162ee98f48966de6b3d (patch) | |
| tree | 4743b2be253b1de0ed6f1144de8dd40f3442a9b0 /Documentation/x86 | |
| parent | 09162bc32c880a791c6c0668ce0745cf7958f576 (diff) | |
| download | linux-028c221ed1904af9ac3c5162ee98f48966de6b3d.tar.gz | |
x86/CPU/AMD: Save AMD NodeId as cpu_die_id
AMD systems provide a "NodeId" value that represents a global ID indicating to which "Node" a logical CPU belongs. The "Node" is a physical structure equivalent to a Die, and it should not be confused with logical structures like NUMA nodes. Logical nodes can be adjusted based on firmware or other settings whereas the physical nodes/dies are fixed based on hardware topology. The NodeId value can be used when a physical ID is needed by software. Save the AMD NodeId to struct cpuinfo_x86.cpu_die_id. Use the value from CPUID or MSR as appropriate. Default to phys_proc_id otherwise. Do so for both AMD and Hygon systems. Drop the node_id parameter from cacheinfo_*_init_llc_id() as it is no longer needed. Update the x86 topology documentation. Suggested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20201109210659.754018-2-Yazen.Ghannam@amd.com
Diffstat (limited to 'Documentation/x86')
| -rw-r--r-- | Documentation/x86/topology.rst | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/Documentation/x86/topology.rst b/Documentation/x86/topology.rst index e29739904e37..7f58010ea86a 100644 --- a/Documentation/x86/topology.rst +++ b/Documentation/x86/topology.rst @@ -41,6 +41,8 @@ Package Packages contain a number of cores plus shared resources, e.g. DRAM controller, shared caches etc. +Modern systems may also use the term 'Die' for package. + AMD nomenclature for package is 'Node'. Package-related topology information in the kernel: @@ -53,11 +55,18 @@ Package-related topology information in the kernel: The number of dies in a package. This information is retrieved via CPUID. + - cpuinfo_x86.cpu_die_id: + + The physical ID of the die. This information is retrieved via CPUID. + - cpuinfo_x86.phys_proc_id: The physical ID of the package. This information is retrieved via CPUID and deduced from the APIC IDs of the cores in the package. + Modern systems use this value for the socket. There may be multiple + packages within a socket. This value may differ from cpu_die_id. + - cpuinfo_x86.logical_proc_id: The logical ID of the package. As we do not trust BIOSes to enumerate the |