drm/nv44/vm: fix and enable use of "real" pciegart

Something seems to be missing in regards to flushing specific ranges of
the TLB.  For the moment, flushing the entire thing seems to make it
work alright.

Should give 39-bit DMA addressing on the relevant chipsets.

v2: allocate contig 16KiB for dummy pages, reported by mwk on irc

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/core/subdev/device/nv40.c b/drivers/gpu/drm/nouveau/core/subdev/device/nv40.c
index 320ccc4..18de4c5 100644
--- a/drivers/gpu/drm/nouveau/core/subdev/device/nv40.c
+++ b/drivers/gpu/drm/nouveau/core/subdev/device/nv40.c
@@ -218,7 +218,7 @@
 		device->oclass[NVDEV_SUBDEV_TIMER  ] = &nv04_timer_oclass;
 		device->oclass[NVDEV_SUBDEV_FB     ] = &nv40_fb_oclass;
 		device->oclass[NVDEV_SUBDEV_INSTMEM] = &nv40_instmem_oclass;
-		device->oclass[NVDEV_SUBDEV_VM     ] = &nv04_vmmgr_oclass;
+		device->oclass[NVDEV_SUBDEV_VM     ] = &nv44_vmmgr_oclass;
 		device->oclass[NVDEV_ENGINE_DMAOBJ ] = &nv04_dmaeng_oclass;
 		device->oclass[NVDEV_ENGINE_FIFO   ] = &nv40_fifo_oclass;
 		device->oclass[NVDEV_ENGINE_SW     ] = &nv10_software_oclass;
@@ -238,7 +238,7 @@
 		device->oclass[NVDEV_SUBDEV_TIMER  ] = &nv04_timer_oclass;
 		device->oclass[NVDEV_SUBDEV_FB     ] = &nv40_fb_oclass;
 		device->oclass[NVDEV_SUBDEV_INSTMEM] = &nv40_instmem_oclass;
-		device->oclass[NVDEV_SUBDEV_VM     ] = &nv04_vmmgr_oclass;
+		device->oclass[NVDEV_SUBDEV_VM     ] = &nv44_vmmgr_oclass;
 		device->oclass[NVDEV_ENGINE_DMAOBJ ] = &nv04_dmaeng_oclass;
 		device->oclass[NVDEV_ENGINE_FIFO   ] = &nv40_fifo_oclass;
 		device->oclass[NVDEV_ENGINE_SW     ] = &nv10_software_oclass;
@@ -258,7 +258,7 @@
 		device->oclass[NVDEV_SUBDEV_TIMER  ] = &nv04_timer_oclass;
 		device->oclass[NVDEV_SUBDEV_FB     ] = &nv40_fb_oclass;
 		device->oclass[NVDEV_SUBDEV_INSTMEM] = &nv40_instmem_oclass;
-		device->oclass[NVDEV_SUBDEV_VM     ] = &nv04_vmmgr_oclass;
+		device->oclass[NVDEV_SUBDEV_VM     ] = &nv44_vmmgr_oclass;
 		device->oclass[NVDEV_ENGINE_DMAOBJ ] = &nv04_dmaeng_oclass;
 		device->oclass[NVDEV_ENGINE_FIFO   ] = &nv40_fifo_oclass;
 		device->oclass[NVDEV_ENGINE_SW     ] = &nv10_software_oclass;
@@ -278,7 +278,7 @@
 		device->oclass[NVDEV_SUBDEV_TIMER  ] = &nv04_timer_oclass;
 		device->oclass[NVDEV_SUBDEV_FB     ] = &nv40_fb_oclass;
 		device->oclass[NVDEV_SUBDEV_INSTMEM] = &nv40_instmem_oclass;
-		device->oclass[NVDEV_SUBDEV_VM     ] = &nv04_vmmgr_oclass;
+		device->oclass[NVDEV_SUBDEV_VM     ] = &nv44_vmmgr_oclass;
 		device->oclass[NVDEV_ENGINE_DMAOBJ ] = &nv04_dmaeng_oclass;
 		device->oclass[NVDEV_ENGINE_FIFO   ] = &nv40_fifo_oclass;
 		device->oclass[NVDEV_ENGINE_SW     ] = &nv10_software_oclass;
@@ -298,7 +298,7 @@
 		device->oclass[NVDEV_SUBDEV_TIMER  ] = &nv04_timer_oclass;
 		device->oclass[NVDEV_SUBDEV_FB     ] = &nv40_fb_oclass;
 		device->oclass[NVDEV_SUBDEV_INSTMEM] = &nv40_instmem_oclass;
-		device->oclass[NVDEV_SUBDEV_VM     ] = &nv04_vmmgr_oclass;
+		device->oclass[NVDEV_SUBDEV_VM     ] = &nv44_vmmgr_oclass;
 		device->oclass[NVDEV_ENGINE_DMAOBJ ] = &nv04_dmaeng_oclass;
 		device->oclass[NVDEV_ENGINE_FIFO   ] = &nv40_fifo_oclass;
 		device->oclass[NVDEV_ENGINE_SW     ] = &nv10_software_oclass;
@@ -318,7 +318,7 @@
 		device->oclass[NVDEV_SUBDEV_TIMER  ] = &nv04_timer_oclass;
 		device->oclass[NVDEV_SUBDEV_FB     ] = &nv40_fb_oclass;
 		device->oclass[NVDEV_SUBDEV_INSTMEM] = &nv40_instmem_oclass;
-		device->oclass[NVDEV_SUBDEV_VM     ] = &nv04_vmmgr_oclass;
+		device->oclass[NVDEV_SUBDEV_VM     ] = &nv44_vmmgr_oclass;
 		device->oclass[NVDEV_ENGINE_DMAOBJ ] = &nv04_dmaeng_oclass;
 		device->oclass[NVDEV_ENGINE_FIFO   ] = &nv40_fifo_oclass;
 		device->oclass[NVDEV_ENGINE_SW     ] = &nv10_software_oclass;
@@ -338,7 +338,7 @@
 		device->oclass[NVDEV_SUBDEV_TIMER  ] = &nv04_timer_oclass;
 		device->oclass[NVDEV_SUBDEV_FB     ] = &nv40_fb_oclass;
 		device->oclass[NVDEV_SUBDEV_INSTMEM] = &nv40_instmem_oclass;
-		device->oclass[NVDEV_SUBDEV_VM     ] = &nv04_vmmgr_oclass;
+		device->oclass[NVDEV_SUBDEV_VM     ] = &nv44_vmmgr_oclass;
 		device->oclass[NVDEV_ENGINE_DMAOBJ ] = &nv04_dmaeng_oclass;
 		device->oclass[NVDEV_ENGINE_FIFO   ] = &nv40_fifo_oclass;
 		device->oclass[NVDEV_ENGINE_SW     ] = &nv10_software_oclass;
@@ -358,7 +358,7 @@
 		device->oclass[NVDEV_SUBDEV_TIMER  ] = &nv04_timer_oclass;
 		device->oclass[NVDEV_SUBDEV_FB     ] = &nv40_fb_oclass;
 		device->oclass[NVDEV_SUBDEV_INSTMEM] = &nv40_instmem_oclass;
-		device->oclass[NVDEV_SUBDEV_VM     ] = &nv04_vmmgr_oclass;
+		device->oclass[NVDEV_SUBDEV_VM     ] = &nv44_vmmgr_oclass;
 		device->oclass[NVDEV_ENGINE_DMAOBJ ] = &nv04_dmaeng_oclass;
 		device->oclass[NVDEV_ENGINE_FIFO   ] = &nv40_fifo_oclass;
 		device->oclass[NVDEV_ENGINE_SW     ] = &nv10_software_oclass;