ACPI: cpufreq: Add highest perf change notification

Platform firmware sends notify 0x85 to inform the OS that the highest
performance of a CPU has changed.

This will be used by the AMD P-state driver to update the ranking of
preferred cores and set the priority of cores accordingly.

Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Perry Yuan <perry.yuan@amd.com>
Signed-off-by: Meng Li <li.meng@amd.com>
Link: https://uefi.org/specs/ACPI/6.5/05_ACPI_Software_Programming_Model.html#processor-device-notification-values
[ rjw: New subject, changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index 4bd16b3..67db60e 100644 (file)
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -27,6 +27,7 @@
 #define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
 #define ACPI_PROCESSOR_NOTIFY_POWER    0x81
 #define ACPI_PROCESSOR_NOTIFY_THROTTLING       0x82
+#define ACPI_PROCESSOR_NOTIFY_HIGEST_PERF_CHANGED      0x85
 
 MODULE_AUTHOR("Paul Diefenbaugh");
 MODULE_DESCRIPTION("ACPI Processor Driver");
@@ -83,6 +84,11 @@ static void acpi_processor_notify(acpi_handle handle, u32 event, void *data)
                acpi_bus_generate_netlink_event(device->pnp.device_class,
                                                  dev_name(&device->dev), event, 0);
                break;
+       case ACPI_PROCESSOR_NOTIFY_HIGEST_PERF_CHANGED:
+               cpufreq_update_limits(pr->id);
+               acpi_bus_generate_netlink_event(device->pnp.device_class,
+                                                 dev_name(&device->dev), event, 0);
+               break;
        default:
                acpi_handle_debug(handle, "Unsupported event [0x%x]\n", event);
                break;

diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index afda5f2..9bebeec 100644 (file)
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -263,6 +263,7 @@ static inline bool cpufreq_supports_freq_invariance(void)
        return false;
 }
 static inline void disable_cpufreq(void) { }
+static inline void cpufreq_update_limits(unsigned int cpu) { }
 #endif
 
 #ifdef CONFIG_CPU_FREQ_STAT