#define OPAL_SLW_SET_REG 100 int64_t opal_slw_set_reg(uint64_t cpu_pir, uint64_t sprn, uint64_t val);
OPAL_SLW_SET_REG is used to inform low-level firmware to restore a given value of SPR when there is a state loss. The actual set of SPRs that are supported is platform dependent.
In Power 8, it uses p8_pore_gen_cpufreq_fixed(), api provided by pore engine, to inform the spr with their corresponding values with which they must be restored.
In Power 9, it uses p9_stop_save_cpureg(), api provided by self restore code, to inform the spr with their corresponding values with which they must be restored.
This parameter specifies the pir of the cpu for which the call is being made.
This parameter specifies the spr number as mentioned in p9_stop_api.H for Power9 and p8_pore_table_gen_api.H for Power8.
This parameter specifices value with which the spr should be restored.