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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2025-06-05 17:07:31 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2025-06-07 14:23:22 +0200
commitf694481b1d3177144fcac4242eb750cfcb9f7bd5 (patch)
treeb17d80635abfb1d8ff2b8430023665b4be34fbe3
parenta430c11f401589a0f4f57fd398271a5d85142c7a (diff)
ACPI: processor: Rescan "dead" SMT siblings during initialization
Make acpi_processor_driver_init() call arch_cpu_rescan_dead_smt_siblings(), via a new wrapper function called acpi_idle_rescan_dead_smt_siblings(), after successfully initializing the driver, to allow the "dead" SMT siblings to go into deep idle states, which is necessary for the processor to be able to reach deep package C-states (like PC10) going forward, so that power can be reduced sufficiently in suspend-to-idle, among other things. However, do it only if the ACPI idle driver is the current cpuidle driver (otherwise it is assumed that another cpuidle driver will take care of this) and avoid doing it on architectures other than x86. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Link: https://patch.msgid.link/2005721.PYKUYFuaPT@rjwysocki.net
-rw-r--r--drivers/acpi/internal.h6
-rw-r--r--drivers/acpi/processor_driver.c3
-rw-r--r--drivers/acpi/processor_idle.c8
3 files changed, 17 insertions, 0 deletions
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index 00910ccd7eda..e2781864fdce 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -175,6 +175,12 @@ bool processor_physically_present(acpi_handle handle);
static inline void acpi_early_processor_control_setup(void) {}
#endif
+#ifdef CONFIG_ACPI_PROCESSOR_CSTATE
+void acpi_idle_rescan_dead_smt_siblings(void);
+#else
+static inline void acpi_idle_rescan_dead_smt_siblings(void) {}
+#endif
+
/* --------------------------------------------------------------------------
Embedded Controller
-------------------------------------------------------------------------- */
diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index 3b281bc1e73c..65e779be64ff 100644
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -279,6 +279,9 @@ static int __init acpi_processor_driver_init(void)
* after acpi_cppc_processor_probe() has been called for all online CPUs
*/
acpi_processor_init_invariance_cppc();
+
+ acpi_idle_rescan_dead_smt_siblings();
+
return 0;
err:
driver_unregister(&acpi_processor_driver);
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index e2febca2ec13..2c2dc559e0f8 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -24,6 +24,8 @@
#include <acpi/processor.h>
#include <linux/context_tracking.h>
+#include "internal.h"
+
/*
* Include the apic definitions for x86 to have the APIC timer related defines
* available also for UP (on SMP it gets magically included via linux/smp.h).
@@ -55,6 +57,12 @@ struct cpuidle_driver acpi_idle_driver = {
};
#ifdef CONFIG_ACPI_PROCESSOR_CSTATE
+void acpi_idle_rescan_dead_smt_siblings(void)
+{
+ if (cpuidle_get_driver() == &acpi_idle_driver)
+ arch_cpu_rescan_dead_smt_siblings();
+}
+
static
DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);