soc/intel/xeon_sp/spr: Add comments for get_thread_count
Add comments to clarify the usage of logical core count instead of
physical core count.
TEST=Build and boot on intel/archercity CRB
Change-Id: I2bc94391f060cec9de91183021da03bc5c7438c0
Signed-off-by: Shuo Liu <shuo.liu@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/82097
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/soc/intel/xeon_sp/spr/cpu.c b/src/soc/intel/xeon_sp/spr/cpu.c
index c9ed8e1..15cb846 100644
--- a/src/soc/intel/xeon_sp/spr/cpu.c
+++ b/src/soc/intel/xeon_sp/spr/cpu.c
@@ -224,6 +224,12 @@
{
unsigned int num_phys = 0, num_virts = 0;
+ /*
+ * This call calculates the thread count which is corresponding to num_virts
+ * (logical cores), while num_phys is corresponding to physical cores (in SMT
+ * system, one physical core has multiple threads, a.k.a. logical cores).
+ * Hence num_phys is not actually used.
+ */
cpu_read_topology(&num_phys, &num_virts);
printk(BIOS_SPEW, "Detected %u cores and %u threads\n", num_phys, num_virts);
return num_virts * soc_get_num_cpus();