1 files changed, 122 insertions, 0 deletions
diff --git a/drivers/gpu/arm/utgard/platform/arm/arm_core_scaling.c b/drivers/gpu/arm/utgard/platform/arm/arm_core_scaling.c
new file mode 100644
index 000000000000..2c24742eb4de
--- /dev/null
+++ b/drivers/gpu/arm/utgard/platform/arm/arm_core_scaling.c
@@ -0,0 +1,122 @@
+/*
+ * Copyright (C) 2013-2015 ARM Limited. All rights reserved.
+ * 
+ * This program is free software and is provided to you under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation, and any use by you of this program is subject to the terms of such GNU licence.
+ * 
+ * A copy of the licence is included with the program, and can also be obtained from Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+/**
+ * @file arm_core_scaling.c
+ * Example core scaling policy.
+ */
+
+#include "arm_core_scaling.h"
+
+#include <linux/mali/mali_utgard.h>
+#include "mali_kernel_common.h"
+
+#include <linux/workqueue.h>
+
+static int num_cores_total;
+static int num_cores_enabled;
+
+static struct work_struct wq_work;
+
+static void set_num_cores(struct work_struct *work)
+{
+	int err = mali_perf_set_num_pp_cores(num_cores_enabled);
+	MALI_DEBUG_ASSERT(0 == err);
+	MALI_IGNORE(err);
+}
+
+static void enable_one_core(void)
+{
+	if (num_cores_enabled < num_cores_total) {
+		++num_cores_enabled;
+		schedule_work(&wq_work);
+		MALI_DEBUG_PRINT(3, ("Core scaling: Enabling one more core\n"));
+	}
+
+	MALI_DEBUG_ASSERT(1 <= num_cores_enabled);
+	MALI_DEBUG_ASSERT(num_cores_total >= num_cores_enabled);
+}
+
+static void disable_one_core(void)
+{
+	if (1 < num_cores_enabled) {
+		--num_cores_enabled;
+		schedule_work(&wq_work);
+		MALI_DEBUG_PRINT(3, ("Core scaling: Disabling one core\n"));
+	}
+
+	MALI_DEBUG_ASSERT(1 <= num_cores_enabled);
+	MALI_DEBUG_ASSERT(num_cores_total >= num_cores_enabled);
+}
+
+static void enable_max_num_cores(void)
+{
+	if (num_cores_enabled < num_cores_total) {
+		num_cores_enabled = num_cores_total;
+		schedule_work(&wq_work);
+		MALI_DEBUG_PRINT(3, ("Core scaling: Enabling maximum number of cores\n"));
+	}
+
+	MALI_DEBUG_ASSERT(num_cores_total == num_cores_enabled);
+}
+
+void mali_core_scaling_init(int num_pp_cores)
+{
+	INIT_WORK(&wq_work, set_num_cores);
+
+	num_cores_total   = num_pp_cores;
+	num_cores_enabled = num_pp_cores;
+
+	/* NOTE: Mali is not fully initialized at this point. */
+}
+
+void mali_core_scaling_sync(int num_cores)
+{
+	num_cores_enabled = num_cores;
+}
+
+void mali_core_scaling_term(void)
+{
+	flush_scheduled_work();
+}
+
+#define PERCENT_OF(percent, max) ((int) ((percent)*(max)/100.0 + 0.5))
+
+void mali_core_scaling_update(struct mali_gpu_utilization_data *data)
+{
+	/*
+	 * This function implements a very trivial PP core scaling algorithm.
+	 *
+	 * It is _NOT_ of production quality.
+	 * The only intention behind this algorithm is to exercise and test the
+	 * core scaling functionality of the driver.
+	 * It is _NOT_ tuned for neither power saving nor performance!
+	 *
+	 * Other metrics than PP utilization need to be considered as well
+	 * in order to make a good core scaling algorithm.
+	 */
+
+	MALI_DEBUG_PRINT(3, ("Utilization: (%3d, %3d, %3d), cores enabled: %d/%d\n", data->utilization_gpu, data->utilization_gp, data->utilization_pp, num_cores_enabled, num_cores_total));
+
+	/* NOTE: this function is normally called directly from the utilization callback which is in
+	 * timer context. */
+
+	if (PERCENT_OF(90, 256) < data->utilization_pp) {
+		enable_max_num_cores();
+	} else if (PERCENT_OF(50, 256) < data->utilization_pp) {
+		enable_one_core();
+	} else if (PERCENT_OF(40, 256) < data->utilization_pp) {
+		/* do nothing */
+	} else if (PERCENT_OF(0, 256) < data->utilization_pp) {
+		disable_one_core();
+	} else {
+		/* do nothing */
+	}
+}