drm/nouveau: prepare for enabling svm with existing userspace interfaces

For a channel to make use of SVM features, it requires a different GPU MMU
configuration than we would normally use, which is not desirable to switch
to unless a client is actively going to use SVM.

In order to supporting SVM without more extensive changes to the userspace
interfaces, the SVM_INIT ioctl needs to replace the previous configuration
safely.

The only way we can currently do this safely, accounting for some unlikely
failure conditions, is to allocate the new VMM without destroying the last
one, and prioritising the SVM-enabled configuration in the code that cares.

This will get cleaned up again further down the track.

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

1 files changed, 11 insertions, 12 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_chan.c b/drivers/gpu/drm/nouveau/nouveau_chan.c
index 668afbc29c3e..5160a0a9c77d 100644
--- a/drivers/gpu/drm/nouveau/nouveau_chan.c
+++ b/drivers/gpu/drm/nouveau/nouveau_chan.c
@@ -130,6 +130,7 @@ nouveau_channel_prep(struct nouveau_drm *drm, struct nvif_device *device,
 
 	chan->device = device;
 	chan->drm = drm;
+	chan->vmm = cli->svm.cli ? &cli->svm : &cli->vmm;
 	atomic_set(&chan->killed, 0);
 
 	/* allocate memory for dma push buffer */
@@ -157,7 +158,7 @@ nouveau_channel_prep(struct nouveau_drm *drm, struct nvif_device *device,
 	chan->push.addr = chan->push.buffer->bo.offset;
 
 	if (device->info.family >= NV_DEVICE_INFO_V0_TESLA) {
-		ret = nouveau_vma_new(chan->push.buffer, &cli->vmm,
+		ret = nouveau_vma_new(chan->push.buffer, chan->vmm,
 				      &chan->push.vma);
 		if (ret) {
 			nouveau_channel_del(pchan);
@@ -172,7 +173,7 @@ nouveau_channel_prep(struct nouveau_drm *drm, struct nvif_device *device,
 		args.target = NV_DMA_V0_TARGET_VM;
 		args.access = NV_DMA_V0_ACCESS_VM;
 		args.start = 0;
-		args.limit = cli->vmm.vmm.limit - 1;
+		args.limit = chan->vmm->vmm.limit - 1;
 	} else
 	if (chan->push.buffer->bo.mem.mem_type == TTM_PL_VRAM) {
 		if (device->info.family == NV_DEVICE_INFO_V0_TNT) {
@@ -202,7 +203,7 @@ nouveau_channel_prep(struct nouveau_drm *drm, struct nvif_device *device,
 			args.target = NV_DMA_V0_TARGET_VM;
 			args.access = NV_DMA_V0_ACCESS_RDWR;
 			args.start = 0;
-			args.limit = cli->vmm.vmm.limit - 1;
+			args.limit = chan->vmm->vmm.limit - 1;
 		}
 	}
 
@@ -220,7 +221,6 @@ static int
 nouveau_channel_ind(struct nouveau_drm *drm, struct nvif_device *device,
 		    u64 runlist, bool priv, struct nouveau_channel **pchan)
 {
-	struct nouveau_cli *cli = (void *)device->object.client;
 	static const u16 oclasses[] = { TURING_CHANNEL_GPFIFO_A,
 					VOLTA_CHANNEL_GPFIFO_A,
 					PASCAL_CHANNEL_GPFIFO_A,
@@ -255,7 +255,7 @@ nouveau_channel_ind(struct nouveau_drm *drm, struct nvif_device *device,
 			args.volta.ilength = 0x02000;
 			args.volta.ioffset = 0x10000 + chan->push.addr;
 			args.volta.runlist = runlist;
-			args.volta.vmm = nvif_handle(&cli->vmm.vmm.object);
+			args.volta.vmm = nvif_handle(&chan->vmm->vmm.object);
 			args.volta.priv = priv;
 			size = sizeof(args.volta);
 		} else
@@ -264,7 +264,7 @@ nouveau_channel_ind(struct nouveau_drm *drm, struct nvif_device *device,
 			args.kepler.ilength = 0x02000;
 			args.kepler.ioffset = 0x10000 + chan->push.addr;
 			args.kepler.runlist = runlist;
-			args.kepler.vmm = nvif_handle(&cli->vmm.vmm.object);
+			args.kepler.vmm = nvif_handle(&chan->vmm->vmm.object);
 			args.kepler.priv = priv;
 			size = sizeof(args.kepler);
 		} else
@@ -272,14 +272,14 @@ nouveau_channel_ind(struct nouveau_drm *drm, struct nvif_device *device,
 			args.fermi.version = 0;
 			args.fermi.ilength = 0x02000;
 			args.fermi.ioffset = 0x10000 + chan->push.addr;
-			args.fermi.vmm = nvif_handle(&cli->vmm.vmm.object);
+			args.fermi.vmm = nvif_handle(&chan->vmm->vmm.object);
 			size = sizeof(args.fermi);
 		} else {
 			args.nv50.version = 0;
 			args.nv50.ilength = 0x02000;
 			args.nv50.ioffset = 0x10000 + chan->push.addr;
 			args.nv50.pushbuf = nvif_handle(&chan->push.ctxdma);
-			args.nv50.vmm = nvif_handle(&cli->vmm.vmm.object);
+			args.nv50.vmm = nvif_handle(&chan->vmm->vmm.object);
 			size = sizeof(args.nv50);
 		}
 
@@ -350,7 +350,6 @@ static int
 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 nv_dma_v0 args = {};
 	int ret, i;
@@ -376,7 +375,7 @@ nouveau_channel_init(struct nouveau_channel *chan, u32 vram, u32 gart)
 			args.target = NV_DMA_V0_TARGET_VM;
 			args.access = NV_DMA_V0_ACCESS_VM;
 			args.start = 0;
-			args.limit = cli->vmm.vmm.limit - 1;
+			args.limit = chan->vmm->vmm.limit - 1;
 		} else {
 			args.target = NV_DMA_V0_TARGET_VRAM;
 			args.access = NV_DMA_V0_ACCESS_RDWR;
@@ -393,7 +392,7 @@ nouveau_channel_init(struct nouveau_channel *chan, u32 vram, u32 gart)
 			args.target = NV_DMA_V0_TARGET_VM;
 			args.access = NV_DMA_V0_ACCESS_VM;
 			args.start = 0;
-			args.limit = cli->vmm.vmm.limit - 1;
+			args.limit = chan->vmm->vmm.limit - 1;
 		} else
 		if (chan->drm->agp.bridge) {
 			args.target = NV_DMA_V0_TARGET_AGP;
@@ -405,7 +404,7 @@ nouveau_channel_init(struct nouveau_channel *chan, u32 vram, u32 gart)
 			args.target = NV_DMA_V0_TARGET_VM;
 			args.access = NV_DMA_V0_ACCESS_RDWR;
 			args.start = 0;
-			args.limit = cli->vmm.vmm.limit - 1;
+			args.limit = chan->vmm->vmm.limit - 1;
 		}
 
 		ret = nvif_object_init(&chan->user, gart, NV_DMA_IN_MEMORY,