psr: occ: Add support to change power-shifting-ratio

Add support to set the CPU-GPU power shifting ratio which is used by
the OCC power capping algorithm. PSR value of 100 takes all power away
from CPU first and a PSR value of 0 caps GPU first.

Documentation enhanced by Stewart Smith.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

1 files changed, 42 insertions, 0 deletions

diff --git a/core/psr.c b/core/psr.c
new file mode 100644
index 0000000..d3ff6ac
--- /dev/null
+++ b/core/psr.c
@@ -0,0 +1,42 @@
+/* Copyright 2017 IBM Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *	http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <psr.h>
+
+static int opal_get_power_shift_ratio(u32 handle, int token __unused,
+				      u32 *ratio)
+{
+	if (!ratio || !opal_addr_valid(ratio))
+		return OPAL_PARAMETER;
+
+	if (psr_get_class(handle) == PSR_CLASS_OCC)
+		return occ_get_psr(handle, ratio);
+
+	return OPAL_UNSUPPORTED;
+};
+
+opal_call(OPAL_GET_POWER_SHIFT_RATIO, opal_get_power_shift_ratio, 3);
+
+static int opal_set_power_shift_ratio(u32 handle, int token,
+				      u32 ratio)
+{
+	if (psr_get_class(handle) == PSR_CLASS_OCC)
+		return occ_set_psr(handle, token, ratio);
+
+	return OPAL_UNSUPPORTED;
+};
+
+opal_call(OPAL_SET_POWER_SHIFT_RATIO, opal_set_power_shift_ratio, 3);