x86/cpu/topology: Add support for the AMD 0x80000026 leaf

x86/cpu/topology: Add support for the AMD 0x80000026 leaf

On AMD processors that support extended CPUID leaf 0x80000026, use the
extended leaf to parse the topology information. In case of a failure,
fall back to parsing the information from CPUID leaf 0xb.

CPUID leaf 0x80000026 exposes the "CCX" and "CCD (Die)" information on
AMD processors which have been mapped to TOPO_TILE_DOMAIN and
TOPO_DIE_DOMAIN respectively.

Since this information was previously not available via CPUID leaf 0xb
or 0x8000001e, the "die_id", "logical_die_id", "max_die_per_pkg",
"die_cpus", and "die_cpus_list" will differ with this addition on
AMD processors that support extended CPUID leaf 0x80000026 and contain
more than one "CCD (Die)" on the package.

For example, following are the changes in the values reported by
"/sys/kernel/debug/x86/topo/cpus/16" after applying this patch on a 4th
Generation AMD EPYC System (1 x 128C/256T):

  (CPU16 is the first CPU of the second CCD on the package)

		   tip:x86/apic      tip:x86/apic
				     + this patch

  online:              1                  1
  initial_apicid:      80                 80
  apicid:              80                 80
  pkg_id:              0                  0
  die_id:              0                  4       *
  cu_id:               255                255
  core_id:             64                 64
  logical_pkg_id:      0                  0
  logical_die_id:      0                  4       *
  llc_id:              8                  8
  l2c_id:              65535              65535
  amd_node_id:         0                  0
  amd_nodes_per_pkg:   1                  1
  num_threads:         256                256
  num_cores:           128                128
  max_dies_per_pkg:    1                  8       *
  max_threads_per_core:2                  2

[ prateek: commit log, updated comment in topoext_amd.c, changed has_0xb
  to has_topoext, rebased the changes on tip:x86/apic, tested the
  changes on 4th Gen AMD EPYC system ]

[ mingo: tidy up the changelog a bit more ]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240314050432.1710-1-kprateek.nayak@amd.com