From: "Rafael J. Wysocki" rafael.j.wysocki@intel.com
mainline inclusion from mainline-v5.6-rc1 commit 9f3d6daf61e5156139cd05643f7f1c2a9b7b49b0 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I47H3V CVE: NA
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commit 9f3d6daf61e5156139cd05643f7f1c2a9b7b49b0 upstream
Move the C-state verification and checks from intel_idle_cpuidle_driver_init() to a separate function, intel_idle_verify_cstate(), and make the former call it after checking the CPUIDLE_FLAG_UNUSABLE state flag.
Also combine the drv->states[] updates with the incrementation of drv->state_count.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: yjia yingbao.jia@intel.com Signed-off-by: Jackie Liu liuyun01@kylinos.cn Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Reviewed-by: Hanjun Guo guohanjun@huawei.com Reviewed-by: Xie XiuQi xiexiuqi@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- drivers/idle/intel_idle.c | 49 ++++++++++++++++++++------------------- 1 file changed, 25 insertions(+), 24 deletions(-)
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index c4bb67ed8da3..4bb1fc966c95 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -956,6 +956,22 @@ static void intel_idle_s2idle(struct cpuidle_device *dev, mwait_idle_with_hints(eax, ecx); }
+static bool intel_idle_verify_cstate(unsigned int mwait_hint) +{ + unsigned int mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint) + 1; + unsigned int num_substates = (mwait_substates >> mwait_cstate * 4) & + MWAIT_SUBSTATE_MASK; + + /* Ignore the C-state if there are NO sub-states in CPUID for it. */ + if (num_substates == 0) + return false; + + if (mwait_cstate > 2 && !boot_cpu_has(X86_FEATURE_NONSTOP_TSC)) + mark_tsc_unstable("TSC halts in idle states deeper than C2"); + + return true; +} + static void __setup_broadcast_timer(bool on) { if (on) @@ -1346,10 +1362,10 @@ static void __init intel_idle_cpuidle_driver_init(void) drv->state_count = 1;
for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) { - int num_substates, mwait_hint, mwait_cstate; + unsigned int mwait_hint;
- if ((cpuidle_state_table[cstate].enter == NULL) && - (cpuidle_state_table[cstate].enter_s2idle == NULL)) + if (!cpuidle_state_table[cstate].enter && + !cpuidle_state_table[cstate].enter_s2idle) break;
if (cstate + 1 > max_cstate) { @@ -1357,34 +1373,19 @@ static void __init intel_idle_cpuidle_driver_init(void) break; }
- mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags); - mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint); - - /* number of sub-states for this state in CPUID.MWAIT */ - num_substates = (mwait_substates >> ((mwait_cstate + 1) * 4)) - & MWAIT_SUBSTATE_MASK; - - /* if NO sub-states for this state in CPUID, skip it */ - if (num_substates == 0) - continue; - - /* if state marked as disabled, skip it */ + /* If marked as unusable, skip this state. */ if (cpuidle_state_table[cstate].disabled != 0) { pr_debug("state %s is disabled\n", cpuidle_state_table[cstate].name); continue; }
+ mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags); + if (!intel_idle_verify_cstate(mwait_hint)) + continue;
- if (((mwait_cstate + 1) > 2) && - !boot_cpu_has(X86_FEATURE_NONSTOP_TSC)) - mark_tsc_unstable("TSC halts in idle" - " states deeper than C2"); - - drv->states[drv->state_count] = /* structure copy */ - cpuidle_state_table[cstate]; - - drv->state_count += 1; + /* Structure copy. */ + drv->states[drv->state_count++] = cpuidle_state_table[cstate]; }
if (icpu->byt_auto_demotion_disable_flag) {