drm/nouveau: Add support for basic clockgating on Kepler1

This adds support for enabling automatic clockgating on nvidia GPUs for
Kepler1. While this is not technically a clockgating level, it does
enable clockgating using the clockgating values initially set by the
vbios (which should be safe to use).

This introduces two therm helpers for controlling basic clockgating:
	nvkm_therm_clkgate_enable() - enables clockgating through
	CG_CTRL, done after initializing the GPU fully
	nvkm_therm_clkgate_fini() - prepares clockgating for suspend or
	driver unload

A lot of this code was originally going to be based off of fermi;
however it turns out that while Fermi's the first line of GPUs that
introduced this kind of power saving, Fermi requires more fine tuned
control of the CG_CTRL registers from the driver while reclocking that
we don't entirely understand yet.

For the simple parts we will be sharing with Fermi for certain however,
we at least add those into a new subdev/therm/gf100.h header.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Martin Peres <martin.peres@free.fr>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 50 insertions, 8 deletions

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/therm/base.c b/drivers/gpu/drm/nouveau/nvkm/subdev/therm/base.c
index f27fc6d0d4c6..cf1d5af30f5f 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/therm/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/therm/base.c
@@ -21,6 +21,7 @@
  *
  * Authors: Martin Peres
  */
+#include <nvkm/core/option.h>
 #include "priv.h"
 
 int
@@ -297,6 +298,38 @@ nvkm_therm_attr_set(struct nvkm_therm *therm,
 	return -EINVAL;
 }
 
+void
+nvkm_therm_clkgate_enable(struct nvkm_therm *therm)
+{
+	if (!therm->func->clkgate_enable || !therm->clkgating_enabled)
+		return;
+
+	nvkm_debug(&therm->subdev,
+		   "Enabling clockgating\n");
+	therm->func->clkgate_enable(therm);
+}
+
+void
+nvkm_therm_clkgate_fini(struct nvkm_therm *therm, bool suspend)
+{
+	if (!therm->func->clkgate_fini || !therm->clkgating_enabled)
+		return;
+
+	nvkm_debug(&therm->subdev,
+		   "Preparing clockgating for %s\n",
+		   suspend ? "suspend" : "fini");
+	therm->func->clkgate_fini(therm, suspend);
+}
+
+static void
+nvkm_therm_clkgate_oneinit(struct nvkm_therm *therm)
+{
+	if (!therm->func->clkgate_enable || !therm->clkgating_enabled)
+		return;
+
+	nvkm_info(&therm->subdev, "Clockgating enabled\n");
+}
+
 static void
 nvkm_therm_intr(struct nvkm_subdev *subdev)
 {
@@ -333,6 +366,7 @@ nvkm_therm_oneinit(struct nvkm_subdev *subdev)
 	nvkm_therm_fan_ctor(therm);
 	nvkm_therm_fan_mode(therm, NVKM_THERM_CTRL_AUTO);
 	nvkm_therm_sensor_preinit(therm);
+	nvkm_therm_clkgate_oneinit(therm);
 	return 0;
 }
 
@@ -374,15 +408,10 @@ nvkm_therm = {
 	.intr = nvkm_therm_intr,
 };
 
-int
-nvkm_therm_new_(const struct nvkm_therm_func *func, struct nvkm_device *device,
-		int index, struct nvkm_therm **ptherm)
+void
+nvkm_therm_ctor(struct nvkm_therm *therm, struct nvkm_device *device,
+		int index, const struct nvkm_therm_func *func)
 {
-	struct nvkm_therm *therm;
-
-	if (!(therm = *ptherm = kzalloc(sizeof(*therm), GFP_KERNEL)))
-		return -ENOMEM;
-
 	nvkm_subdev_ctor(&nvkm_therm, device, index, &therm->subdev);
 	therm->func = func;
 
@@ -395,5 +424,18 @@ nvkm_therm_new_(const struct nvkm_therm_func *func, struct nvkm_device *device,
 	therm->attr_get = nvkm_therm_attr_get;
 	therm->attr_set = nvkm_therm_attr_set;
 	therm->mode = therm->suspend = -1; /* undefined */
+	therm->clkgating_enabled = false;
+}
+
+int
+nvkm_therm_new_(const struct nvkm_therm_func *func, struct nvkm_device *device,
+		int index, struct nvkm_therm **ptherm)
+{
+	struct nvkm_therm *therm;
+
+	if (!(therm = *ptherm = kzalloc(sizeof(*therm), GFP_KERNEL)))
+		return -ENOMEM;
+
+	nvkm_therm_ctor(therm, device, index, func);
 	return 0;
 }