drm/nouveau/kms/nv50-: implement proper push buffer control logic

We had a, what was supposed to be temporary, hack in the KMS code where we'd
completely drain an EVO/NVD channel's push buffer when wrapping to the start
again, instead of treating it as a ring buffer.

Let's fix that, finally.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

9 files changed, 21 insertions, 8 deletions

diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/channv50.h b/drivers/gpu/drm/nouveau/nvkm/engine/disp/channv50.h
index e55054b7329f..9cf2cfe2010c 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/channv50.h
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/channv50.h
@@ -21,6 +21,8 @@ struct nv50_disp_chan {
 
 	struct nvkm_memory *memory;
 	u64 push;
+
+	u32 suspend_put;
 };
 
 struct nv50_disp_chan_func {
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/coregf119.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/coregf119.c
index d162b9cf4eac..689e3cdd959a 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/coregf119.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/coregf119.c
@@ -182,6 +182,8 @@ gf119_disp_core_fini(struct nv50_disp_chan *chan)
 		nvkm_error(subdev, "core fini: %08x\n",
 			   nvkm_rd32(device, 0x610490));
 	}
+
+	chan->suspend_put = nvkm_rd32(device, 0x640000);
 }
 
 static int
@@ -195,7 +197,7 @@ gf119_disp_core_init(struct nv50_disp_chan *chan)
 	nvkm_wr32(device, 0x610498, 0x00010000);
 	nvkm_wr32(device, 0x61049c, 0x00000001);
 	nvkm_mask(device, 0x610490, 0x00000010, 0x00000010);
-	nvkm_wr32(device, 0x640000, 0x00000000);
+	nvkm_wr32(device, 0x640000, chan->suspend_put);
 	nvkm_wr32(device, 0x610490, 0x01000013);
 
 	/* wait for it to go inactive */
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/coregp102.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/coregp102.c
index 5b7f993c73c7..1b435beef3bf 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/coregp102.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/coregp102.c
@@ -36,7 +36,7 @@ gp102_disp_core_init(struct nv50_disp_chan *chan)
 	nvkm_wr32(device, 0x611498, 0x00010000);
 	nvkm_wr32(device, 0x61149c, 0x00000001);
 	nvkm_mask(device, 0x610490, 0x00000010, 0x00000010);
-	nvkm_wr32(device, 0x640000, 0x00000000);
+	nvkm_wr32(device, 0x640000, chan->suspend_put);
 	nvkm_wr32(device, 0x610490, 0x01000013);
 
 	/* wait for it to go inactive */
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/coregv100.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/coregv100.c
index 4592d0e69fec..e20a48f201f6 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/coregv100.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/coregv100.c
@@ -167,6 +167,7 @@ gv100_disp_core_fini(struct nv50_disp_chan *chan)
 	nvkm_mask(device, 0x6104e0, 0x00000010, 0x00000000);
 	gv100_disp_core_idle(chan);
 	nvkm_mask(device, 0x6104e0, 0x00000002, 0x00000000);
+	chan->suspend_put = nvkm_rd32(device, 0x680000);
 }
 
 static int
@@ -181,7 +182,7 @@ gv100_disp_core_init(struct nv50_disp_chan *chan)
 	nvkm_wr32(device, 0x610b2c, 0x00000040);
 
 	nvkm_mask(device, 0x6104e0, 0x00000010, 0x00000010);
-	nvkm_wr32(device, 0x680000, 0x00000000);
+	nvkm_wr32(device, 0x680000, chan->suspend_put);
 	nvkm_wr32(device, 0x6104e0, 0x00000013);
 	return gv100_disp_core_idle(chan);
 }
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/corenv50.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/corenv50.c
index 55db9a22b4be..660310b27f9c 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/corenv50.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/corenv50.c
@@ -179,6 +179,8 @@ nv50_disp_core_fini(struct nv50_disp_chan *chan)
 		nvkm_error(subdev, "core fini: %08x\n",
 			   nvkm_rd32(device, 0x610200));
 	}
+
+	chan->suspend_put = nvkm_rd32(device, 0x640000);
 }
 
 static int
@@ -198,7 +200,7 @@ nv50_disp_core_init(struct nv50_disp_chan *chan)
 	nvkm_wr32(device, 0x610208, 0x00010000);
 	nvkm_wr32(device, 0x61020c, 0x00000000);
 	nvkm_mask(device, 0x610200, 0x00000010, 0x00000010);
-	nvkm_wr32(device, 0x640000, 0x00000000);
+	nvkm_wr32(device, 0x640000, chan->suspend_put);
 	nvkm_wr32(device, 0x610200, 0x01000013);
 
 	/* wait for it to go inactive */
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dmacgf119.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dmacgf119.c
index edf7dd0d931d..76425e8586da 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dmacgf119.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dmacgf119.c
@@ -53,6 +53,8 @@ gf119_disp_dmac_fini(struct nv50_disp_chan *chan)
 		nvkm_error(subdev, "ch %d fini: %08x\n", user,
 			   nvkm_rd32(device, 0x610490 + (ctrl * 0x10)));
 	}
+
+	chan->suspend_put = nvkm_rd32(device, 0x640000 + (ctrl * 0x1000));
 }
 
 static int
@@ -68,7 +70,7 @@ gf119_disp_dmac_init(struct nv50_disp_chan *chan)
 	nvkm_wr32(device, 0x610498 + (ctrl * 0x0010), 0x00010000);
 	nvkm_wr32(device, 0x61049c + (ctrl * 0x0010), 0x00000001);
 	nvkm_mask(device, 0x610490 + (ctrl * 0x0010), 0x00000010, 0x00000010);
-	nvkm_wr32(device, 0x640000 + (ctrl * 0x1000), 0x00000000);
+	nvkm_wr32(device, 0x640000 + (ctrl * 0x1000), chan->suspend_put);
 	nvkm_wr32(device, 0x610490 + (ctrl * 0x0010), 0x00000013);
 
 	/* wait for it to go inactive */
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dmacgp102.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dmacgp102.c
index f21a433199aa..da258df268d7 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dmacgp102.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dmacgp102.c
@@ -38,7 +38,7 @@ gp102_disp_dmac_init(struct nv50_disp_chan *chan)
 	nvkm_wr32(device, 0x611498 + (ctrl * 0x0010), 0x00010000);
 	nvkm_wr32(device, 0x61149c + (ctrl * 0x0010), 0x00000001);
 	nvkm_mask(device, 0x610490 + (ctrl * 0x0010), 0x00000010, 0x00000010);
-	nvkm_wr32(device, 0x640000 + (ctrl * 0x1000), 0x00000000);
+	nvkm_wr32(device, 0x640000 + (ctrl * 0x1000), chan->suspend_put);
 	nvkm_wr32(device, 0x610490 + (ctrl * 0x0010), 0x00000013);
 
 	/* wait for it to go inactive */
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dmacgv100.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dmacgv100.c
index eac0e42da354..fdb624ac6b87 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dmacgv100.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dmacgv100.c
@@ -50,10 +50,12 @@ void
 gv100_disp_dmac_fini(struct nv50_disp_chan *chan)
 {
 	struct nvkm_device *device = chan->disp->base.engine.subdev.device;
+	const u32 uoff = (chan->chid.ctrl - 1) * 0x1000;
 	const u32 coff = chan->chid.ctrl * 0x04;
 	nvkm_mask(device, 0x6104e0 + coff, 0x00000010, 0x00000000);
 	gv100_disp_dmac_idle(chan);
 	nvkm_mask(device, 0x6104e0 + coff, 0x00000002, 0x00000000);
+	chan->suspend_put = nvkm_rd32(device, 0x690000 + uoff);
 }
 
 int
@@ -71,7 +73,7 @@ gv100_disp_dmac_init(struct nv50_disp_chan *chan)
 	nvkm_wr32(device, 0x610b2c + poff, 0x00000040);
 
 	nvkm_mask(device, 0x6104e0 + coff, 0x00000010, 0x00000010);
-	nvkm_wr32(device, 0x690000 + uoff, 0x00000000);
+	nvkm_wr32(device, 0x690000 + uoff, chan->suspend_put);
 	nvkm_wr32(device, 0x6104e0 + coff, 0x00000013);
 	return gv100_disp_dmac_idle(chan);
 }
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dmacnv50.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dmacnv50.c
index 9e8a9d7a9b68..d0a7da96d62b 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dmacnv50.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dmacnv50.c
@@ -94,6 +94,8 @@ nv50_disp_dmac_fini(struct nv50_disp_chan *chan)
 		nvkm_error(subdev, "ch %d fini timeout, %08x\n", user,
 			   nvkm_rd32(device, 0x610200 + (ctrl * 0x10)));
 	}
+
+	chan->suspend_put = nvkm_rd32(device, 0x640000 + (ctrl * 0x1000));
 }
 
 static int
@@ -109,7 +111,7 @@ nv50_disp_dmac_init(struct nv50_disp_chan *chan)
 	nvkm_wr32(device, 0x610208 + (ctrl * 0x0010), 0x00010000);
 	nvkm_wr32(device, 0x61020c + (ctrl * 0x0010), ctrl);
 	nvkm_mask(device, 0x610200 + (ctrl * 0x0010), 0x00000010, 0x00000010);
-	nvkm_wr32(device, 0x640000 + (ctrl * 0x1000), 0x00000000);
+	nvkm_wr32(device, 0x640000 + (ctrl * 0x1000), chan->suspend_put);
 	nvkm_wr32(device, 0x610200 + (ctrl * 0x0010), 0x00000013);
 
 	/* wait for it to go inactive */