From: Doug Smythies <doug.smythies@xxxxxxxxx>
[ Upstream commit d9a7e9df731670acdc69e81748941ad338f47fab ]
If HWP has been already been enabled by BIOS, it may be
necessary to override some kernel command line parameters.
Once it has been enabled it requires a reset to be disabled.
Suggested-by: Rafael J. Wysocki <rafael@xxxxxxxxxx>
Signed-off-by: Doug Smythies <dsmythies@xxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++--------
1 file changed, 14 insertions(+), 8 deletions(-)
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index bb4549959b11..e7cd3882bda4 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -3251,11 +3251,15 @@ static int __init intel_pstate_init(void)
if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
return -ENODEV;
- if (no_load)
- return -ENODEV;
-
id = x86_match_cpu(hwp_support_ids);
if (id) {
+ bool hwp_forced = intel_pstate_hwp_is_enabled();
+
+ if (hwp_forced)
+ pr_info("HWP enabled by BIOS\n");
+ else if (no_load)
+ return -ENODEV;
+
copy_cpu_funcs(&core_funcs);
/*
* Avoid enabling HWP for processors without EPP support,
@@ -3265,8 +3269,7 @@ static int __init intel_pstate_init(void)
* If HWP is enabled already, though, there is no choice but to
* deal with it.
*/
- if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) ||
- intel_pstate_hwp_is_enabled()) {
+ if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) || hwp_forced) {
hwp_active++;
hwp_mode_bdw = id->driver_data;
intel_pstate.attr = hwp_cpufreq_attrs;
@@ -3278,7 +3281,11 @@ static int __init intel_pstate_init(void)
goto hwp_cpu_matched;
}
+ pr_info("HWP not enabled\n");
} else {
+ if (no_load)
+ return -ENODEV;
+
id = x86_match_cpu(intel_pstate_cpu_ids);
if (!id) {
pr_info("CPU model not supported\n");
@@ -3357,10 +3364,9 @@ static int __init intel_pstate_setup(char *str)
else if (!strcmp(str, "passive"))
default_driver = &intel_cpufreq;
- if (!strcmp(str, "no_hwp")) {
- pr_info("HWP disabled\n");
+ if (!strcmp(str, "no_hwp"))
no_hwp = 1;
- }
+
if (!strcmp(str, "force"))
force_load = 1;
if (!strcmp(str, "hwp_only"))
--
2.33.0
