[TF-A] How does SPM impact PSCI functions?

Hi,

I just find that secondary CA53 CPUs boot fail with error -95(as below definition and log) in the kernel after enabling SPM with option: SPD=spmd SPMD_SPM_AT_SEL2=0. How does SPM impact PSCI functions? Or which code lines should I check to debug this?

#define EOPNOTSUPP 95 /* Operation not supported on transport endpoint */

[ 0.066970] smp: Bringing up secondary CPUs ... [ 0.071681] psci: failed to boot CPU1 (-95) [ 0.075454] CPU1: failed to boot: -95 [ 0.079591] psci: failed to boot CPU2 (-95) [ 0.083308] CPU2: failed to boot: -95

Regards, Jun