drm/nouveau: request notifications for channels that have been killed

These will be used to improve error recovery behaviour.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_chan.c

@@ -45,6 +45,16 @@ MODULE_PARM_DESC(vram_pushbuf, "Create DMA push buffers in VRAM");
 int nouveau_vram_pushbuf;
 module_param_named(vram_pushbuf, nouveau_vram_pushbuf, int, 0400);
 
+static int
+nouveau_channel_killed(struct nvif_notify *ntfy)
+{
+	struct nouveau_channel *chan = container_of(ntfy, typeof(*chan), kill);
+	struct nouveau_cli *cli = (void *)chan->user.client;
+	NV_PRINTK(warn, cli, "channel %d killed!\n", chan->chid);
+	atomic_set(&chan->killed, 1);
+	return NVIF_NOTIFY_DROP;
+}
+
 int
 nouveau_channel_idle(struct nouveau_channel *chan)
 {
@@ -78,6 +88,7 @@ nouveau_channel_del(struct nouveau_channel **pchan)
 		nvif_object_fini(&chan->nvsw);
 		nvif_object_fini(&chan->gart);
 		nvif_object_fini(&chan->vram);
+		nvif_notify_fini(&chan->kill);
 		nvif_object_fini(&chan->user);
 		nvif_object_fini(&chan->push.ctxdma);
 		nouveau_bo_vma_del(chan->push.buffer, &chan->push.vma);
@@ -107,6 +118,7 @@ nouveau_channel_prep(struct nouveau_drm *drm, struct nvif_device *device,
 
 	chan->device = device;
 	chan->drm = drm;
+	atomic_set(&chan->killed, 0);
 
 	/* allocate memory for dma push buffer */
 	target = TTM_PL_FLAG_TT | TTM_PL_FLAG_UNCACHED;
@@ -301,12 +313,26 @@ nouveau_channel_init(struct nouveau_channel *chan, u32 vram, u32 gart)
 {
 	struct nvif_device *device = chan->device;
 	struct nouveau_cli *cli = (void *)chan->user.client;
+	struct nouveau_drm *drm = chan->drm;
 	struct nvkm_mmu *mmu = nvxx_mmu(device);
 	struct nv_dma_v0 args = {};
 	int ret, i;
 
 	nvif_object_map(&chan->user);
 
+	if (chan->user.oclass >= FERMI_CHANNEL_GPFIFO) {
+		ret = nvif_notify_init(&chan->user, nouveau_channel_killed,
+				       true, NV906F_V0_NTFY_KILLED,
+				       NULL, 0, 0, &chan->kill);
+		if (ret == 0)
+			ret = nvif_notify_get(&chan->kill);
+		if (ret) {
+			NV_ERROR(drm, "Failed to request channel kill "
+				      "notification: %d\n", ret);
+			return ret;
+		}
+	}
+
 	/* allocate dma objects to cover all allowed vram, and gart */
 	if (device->info.family < NV_DEVICE_INFO_V0_FERMI) {
 		if (device->info.family >= NV_DEVICE_INFO_V0_TESLA) {

drivers/gpu/drm/nouveau/nouveau_chan.h

 #ifndef __NOUVEAU_CHAN_H__
 #define __NOUVEAU_CHAN_H__
-
 #include <nvif/object.h>
+#include <nvif/notify.h>
 struct nvif_device;
 
 struct nouveau_channel {
@@ -38,6 +38,9 @@ struct nouveau_channel {
 	u32 user_put;
 
 	struct nvif_object user;
+
+	struct nvif_notify kill;
+	atomic_t killed;
 };