From c935ddfe65da020f5896fa58746fc7a57a876df3 Mon Sep 17 00:00:00 2001 From: Srinivas Pandruvada Date: Mon, 5 May 2025 13:27:22 -0700 Subject: [PATCH] platform/x86: ISST: Do Not Restore SST MSRs on CPU Online Operation MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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: Srinivas Pandruvada Link: https://lore.kernel.org/r/20250505202722.1048675-1-srinivas.pandruvada@linux.intel.com Reviewed-by: Ilpo Järvinen Signed-off-by: Ilpo Järvinen --- .../intel/speed_select_if/isst_if_common.c | 21 ------------------- 1 file changed, 21 deletions(-) diff --git a/drivers/platform/x86/intel/speed_select_if/isst_if_common.c b/drivers/platform/x86/intel/speed_select_if/isst_if_common.c index 31239a93dd71..3c4198ce17f2 100644 --- a/drivers/platform/x86/intel/speed_select_if/isst_if_common.c +++ b/drivers/platform/x86/intel/speed_select_if/isst_if_common.c @@ -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; } -- 2.50.1