drm/nouveau/gr/gf100-: call FECS WFI_GOLDEN_SAVE method

This won't work on Ampere, and, it's questionable whether we should have
been using our FW's method of storing the golden context image with NV's
firmware to begin with.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>

drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgf100.c

@@ -1496,6 +1496,7 @@ gf100_grctx_generate(struct gf100_gr *gr, struct gf100_gr_chan *chan, struct nvk
 
 	grctx->main(chan);
 
+	if (!gr->firmware) {
 		/* Trigger a context unload by unsetting the "next channel valid" bit
 		 * and faking a context switch interrupt.
 		 */
@@ -1508,6 +1509,13 @@ gf100_grctx_generate(struct gf100_gr *gr, struct gf100_gr_chan *chan, struct nvk
 			ret = -EBUSY;
 			goto done_inst;
 		}
+	} else {
+		ret = gf100_gr_fecs_wfi_golden_save(gr, 0x80000000 | addr);
+		if (ret)
+			goto done_inst;
+
+		nvkm_mask(device, 0x409b00, 0x80000000, 0x00000000);
+	}
 
 	gr->data = kmalloc(gr->size, GFP_KERNEL);
 	if (gr->data) {

drivers/gpu/drm/nouveau/nvkm/engine/gr/gf100.c

@@ -796,6 +796,25 @@ gf100_gr_fecs_stop_ctxsw(struct nvkm_gr *base)
 	return ret;
 }
 
+int
+gf100_gr_fecs_wfi_golden_save(struct gf100_gr *gr, u32 inst)
+{
+	struct nvkm_device *device = gr->base.engine.subdev.device;
+
+	nvkm_mask(device, 0x409800, 0x00000003, 0x00000000);
+	nvkm_wr32(device, 0x409500, inst);
+	nvkm_wr32(device, 0x409504, 0x00000009);
+	nvkm_msec(device, 2000,
+		u32 stat = nvkm_rd32(device, 0x409800);
+		if (stat & 0x00000002)
+			return -EIO;
+		if (stat & 0x00000001)
+			return 0;
+	);
+
+	return -ETIMEDOUT;
+}
+
 int
 gf100_gr_fecs_bind_pointer(struct gf100_gr *gr, u32 inst)
 {

drivers/gpu/drm/nouveau/nvkm/engine/gr/gf100.h

@@ -129,6 +129,7 @@ struct gf100_gr {
 };
 
 int gf100_gr_fecs_bind_pointer(struct gf100_gr *, u32 inst);
+int gf100_gr_fecs_wfi_golden_save(struct gf100_gr *, u32 inst);
 
 struct gf100_gr_func_zbc {
 	void (*clear_color)(struct gf100_gr *, int zbc);