[Nouveau] [PATCH v4 27/37] clk: make pstate a pointer to nvkm_pstate

[Karol Herbst]

we will access the current set cstate at least every second and this safes us
some CPU cycles looking them up every second.

Signed-off-by: Karol Herbst <nouveau at karolherbst.de>
---
 drm/nouveau/include/nvkm/subdev/clk.h |  2 +-
 drm/nouveau/nvkm/engine/device/ctrl.c |  5 ++++-
 drm/nouveau/nvkm/subdev/clk/base.c    | 12 ++++++++----
 drm/nouveau/nvkm/subdev/pmu/gk20a.c   | 23 +++++++----------------
 4 files changed, 20 insertions(+), 22 deletions(-)

diff --git a/drm/nouveau/include/nvkm/subdev/clk.h b/drm/nouveau/include/nvkm/subdev/clk.h
index db52e65..4fb2c1b 100644
--- a/drm/nouveau/include/nvkm/subdev/clk.h
+++ b/drm/nouveau/include/nvkm/subdev/clk.h
@@ -91,7 +91,7 @@ struct nvkm_clk {
 
 	struct nvkm_notify pwrsrc_ntfy;
 	int pwrsrc;
-	int pstate; /* current */
+	struct nvkm_pstate *pstate; /* current */
 	int ustate_ac; /* user-requested (-1 disabled, -2 perfmon) */
 	int ustate_dc; /* user-requested (-1 disabled, -2 perfmon) */
 	int astate; /* perfmon adjustment (base) */
diff --git a/drm/nouveau/nvkm/engine/device/ctrl.c b/drm/nouveau/nvkm/engine/device/ctrl.c
index 039e8a4..cb85266 100644
--- a/drm/nouveau/nvkm/engine/device/ctrl.c
+++ b/drm/nouveau/nvkm/engine/device/ctrl.c
@@ -52,7 +52,10 @@ nvkm_control_mthd_pstate_info(struct nvkm_control *ctrl, void *data, u32 size)
 		args->v0.ustate_ac = clk->ustate_ac;
 		args->v0.ustate_dc = clk->ustate_dc;
 		args->v0.pwrsrc = clk->pwrsrc;
-		args->v0.pstate = clk->pstate;
+		if (clk->pstate)
+			args->v0.pstate = clk->pstate->pstate;
+		else
+			args->v0.pstate = -1;
 	} else {
 		args->v0.count = 0;
 		args->v0.ustate_ac = NVIF_CONTROL_PSTATE_INFO_V0_USTATE_DISABLE;
diff --git a/drm/nouveau/nvkm/subdev/clk/base.c b/drm/nouveau/nvkm/subdev/clk/base.c
index 3867ab7..762dfe2 100644
--- a/drm/nouveau/nvkm/subdev/clk/base.c
+++ b/drm/nouveau/nvkm/subdev/clk/base.c
@@ -288,7 +288,7 @@ nvkm_pstate_prog(struct nvkm_clk *clk, int pstatei)
 	}
 
 	nvkm_debug(subdev, "setting performance state %d\n", pstatei);
-	clk->pstate = pstatei;
+	clk->pstate = pstate;
 
 	nvkm_pcie_set_link(pci, pstate->pcie_speed, pstate->pcie_width);
 
@@ -317,15 +317,19 @@ nvkm_clk_update_work(struct work_struct *work)
 		return;
 	clk->pwrsrc = power_supply_is_system_supplied();
 
+	if (clk->pstate)
+		pstate = clk->pstate->pstate;
+	else
+		pstate = -1;
 	nvkm_trace(subdev, "P %d PWR %d U(AC) %d U(DC) %d A %d\n",
-		   clk->pstate, clk->pwrsrc, clk->ustate_ac, clk->ustate_dc,
+		   pstate, clk->pwrsrc, clk->ustate_ac, clk->ustate_dc,
 		   clk->astate);
 
 	pstate = clk->pwrsrc ? clk->ustate_ac : clk->ustate_dc;
 	if (clk->state_nr && pstate != -1) {
 		pstate = (pstate < 0) ? clk->astate : pstate;
 	} else {
-		pstate = clk->pstate = -1;
+		pstate = -1;
 	}
 
 	nvkm_trace(subdev, "-> %d\n", pstate);
@@ -609,7 +613,7 @@ nvkm_clk_init(struct nvkm_subdev *subdev)
 		return clk->func->init(clk);
 
 	clk->astate = clk->state_nr - 1;
-	clk->pstate = -1;
+	clk->pstate = NULL;
 	nvkm_clk_update(clk, true);
 	return 0;
 }
diff --git a/drm/nouveau/nvkm/subdev/pmu/gk20a.c b/drm/nouveau/nvkm/subdev/pmu/gk20a.c
index f996d90..6f0d290 100644
--- a/drm/nouveau/nvkm/subdev/pmu/gk20a.c
+++ b/drm/nouveau/nvkm/subdev/pmu/gk20a.c
@@ -57,24 +57,21 @@ gk20a_pmu_dvfs_target(struct gk20a_pmu *pmu, int *state)
 }
 
 static int
-gk20a_pmu_dvfs_get_cur_state(struct gk20a_pmu *pmu, int *state)
-{
-	struct nvkm_clk *clk = pmu->base.subdev.device->clk;
-
-	*state = clk->pstate;
-	return 0;
-}
-
-static int
 gk20a_pmu_dvfs_get_target_state(struct gk20a_pmu *pmu,
 				int *state, int load)
 {
 	struct gk20a_pmu_dvfs_data *data = pmu->data;
 	struct nvkm_clk *clk = pmu->base.subdev.device->clk;
+	struct nvkm_pstate *pstate = clk->pstate;
 	int cur_level, level;
 
+	if (!pstate) {
+		*state = 0;
+		return 1;
+	}
+
 	/* For GK20A, the performance level is directly mapped to pstate */
-	level = cur_level = clk->pstate;
+	level = cur_level = clk->pstate->pstate;
 
 	if (load > data->p_load_max) {
 		level = min(clk->state_nr - 1, level + (clk->state_nr / 3));
@@ -150,12 +147,6 @@ gk20a_pmu_dvfs_work(struct nvkm_alarm *alarm)
 	nvkm_trace(subdev, "utilization = %d %%, avg_load = %d %%\n",
 		   utilization, data->avg_load);
 
-	ret = gk20a_pmu_dvfs_get_cur_state(pmu, &state);
-	if (ret) {
-		nvkm_warn(subdev, "failed to get current state\n");
-		goto resched;
-	}
-
 	if (gk20a_pmu_dvfs_get_target_state(pmu, &state, data->avg_load)) {
 		nvkm_trace(subdev, "set new state to %d\n", state);
 		gk20a_pmu_dvfs_target(pmu, &state);
-- 
2.8.1