Add the interfaces that architectures shall implement to convey the data
to support IPC classes.
arch_update_ipcc() updates the IPC classification of the current task as
given by hardware.
arch_get_ipcc_score() provides a performance score for a given IPC class
when placed on a specific CPU. Higher scores indicate higher performance.
The number of classes and the score of each class of task are determined
by hardware.
Cc: Ben Segall <bsegall@xxxxxxxxxx>
Cc: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>
Cc: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
Cc: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
Cc: Len Brown <len.brown@xxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Cc: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Tim C. Chen <tim.c.chen@xxxxxxxxx>
Cc: Valentin Schneider <vschneid@xxxxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: linux-pm@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@xxxxxxxxxxxxxxx>
---
Changes since v1:
* Shortened the names of the IPCC interfaces (PeterZ):
sched_task_classes_enabled >> sched_ipcc_enabled
arch_has_task_classes >> arch_has_ipc_classes
arch_update_task_class >> arch_update_ipcc
arch_get_task_class_score >> arch_get_ipcc_score
* Removed smt_siblings_idle argument from arch_update_ipcc(). (PeterZ)
---
kernel/sched/sched.h | 60 +++++++++++++++++++++++++++++++++++++++++
kernel/sched/topology.c | 8 ++++++
2 files changed, 68 insertions(+)
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index b1d338a740e5..75e22baa2622 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -2531,6 +2531,66 @@ void arch_scale_freq_tick(void)
}
#endif
+#ifdef CONFIG_IPC_CLASSES
+DECLARE_STATIC_KEY_FALSE(sched_ipcc);
+
+static inline bool sched_ipcc_enabled(void)
+{
+ return static_branch_unlikely(&sched_ipcc);
+}
+
+#ifndef arch_has_ipc_classes
+/**
+ * arch_has_ipc_classes() - Check whether hardware supports IPC classes of tasks
+ *
+ * Returns: true of IPC classes of tasks are supported.
+ */
+static __always_inline
+bool arch_has_ipc_classes(void)
+{
+ return false;
+}
+#endif
+
+#ifndef arch_update_ipcc
+/**
+ * arch_update_ipcc() - Update the IPC class of the current task
+ * @curr: The current task
+ *
+ * Request that the IPC classification of @curr is updated.
+ *
+ * Returns: none
+ */
+static __always_inline
+void arch_update_ipcc(struct task_struct *curr)
+{
+}
+#endif
+
+#ifndef arch_get_ipcc_score
+/**
+ * arch_get_ipcc_score() - Get the IPC score of a class of task
+ * @ipcc: The IPC class
+ * @cpu: A CPU number
+ *
+ * Returns the performance score of an IPC class when running on @cpu.
+ * Error when either @class or @cpu are invalid.
+ */
+static __always_inline
+int arch_get_ipcc_score(unsigned short ipcc, int cpu)
+{
+ return 1;
+}
+#endif