On my test system, I see SMN accesses from:
amd_pmf_probe() - read
amd_pmc_probe() - read
acp_acp70_audio_probe() - write

Jason Andryuk (2):
  x86/amd_node: Remove smn_exclusive
  x86/amd_node: Avoid divide by zero on virtualized systems

 arch/x86/kernel/amd_node.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

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2.55.0