Unverified Commit c935ddfe authored by Srinivas Pandruvada's avatar Srinivas Pandruvada Committed by Ilpo Järvinen
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platform/x86: ISST: Do Not Restore SST MSRs on CPU Online Operation 



During CPU offline/online operations, the hardware retains MSR settings.
Even if all CPUs are offlined, the package does not lose its MSR
settings.

Therefore, it is unnecessary to restore MSRs which are modified during
the online operation, and this extra step can be removed.

Signed-off-by: default avatarSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Link: https://lore.kernel.org/r/20250505202722.1048675-1-srinivas.pandruvada@linux.intel.com


Reviewed-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
parent c9a20142

drivers/platform/x86/intel/speed_select_if/isst_if_common.c

+0 −21
Original line number Diff line number Diff line
@@ -198,25 +198,6 @@ void isst_resume_common(void) 
}

EXPORT_SYMBOL_GPL(isst_resume_common);



static void isst_restore_msr_local(int cpu)

{

	struct isst_cmd *sst_cmd;

	int i;



	mutex_lock(&isst_hash_lock);

	for (i = 0; i < ARRAY_SIZE(punit_msr_white_list); ++i) {

		if (!punit_msr_white_list[i])

			break;



		hash_for_each_possible(isst_hash, sst_cmd, hnode,

				       punit_msr_white_list[i]) {

			if (!sst_cmd->mbox_cmd_type && sst_cmd->cpu == cpu)

				wrmsrl_safe(sst_cmd->cmd, sst_cmd->data);

		}

	}

	mutex_unlock(&isst_hash_lock);

}



/**

 * isst_if_mbox_cmd_invalid() - Check invalid mailbox commands

 * @cmd: Pointer to the command structure to verify.
@@ -434,8 +415,6 @@ static int isst_if_cpu_online(unsigned int cpu) 
set_punit_id:

	isst_cpu_info[cpu].punit_cpu_id = data;



	isst_restore_msr_local(cpu);



	return 0;

}