drm/nv40: attempt to reserve just enough vram for all 32 channels

This also makes the fact we're giving 512MiB of GART space to all PCIE
boards explicit, although the vast majority (if not all) of them will
now have a ramin_rsvd_vram larger than 2MiB anyway.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_mem.c

@@ -424,14 +424,32 @@ nouveau_mem_vram_init(struct drm_device *dev)
 	}
 
 	/* reserve space at end of VRAM for PRAMIN */
-	if (dev_priv->chipset == 0x40 || dev_priv->chipset == 0x47 ||
-	    dev_priv->chipset == 0x49 || dev_priv->chipset == 0x4b)
-		dev_priv->ramin_rsvd_vram = (2 * 1024 * 1024);
-	else
-	if (dev_priv->card_type >= NV_40)
-		dev_priv->ramin_rsvd_vram = (1 * 1024 * 1024);
-	else
-		dev_priv->ramin_rsvd_vram = (512 * 1024);
+	if (dev_priv->card_type >= NV_50) {
+		dev_priv->ramin_rsvd_vram = 1 * 1024 * 1024;
+	} else
+	if (dev_priv->card_type >= NV_40) {
+		u32 vs = hweight8((nv_rd32(dev, 0x001540) & 0x0000ff00) >> 8);
+		u32 rsvd;
+
+		/* estimate grctx size, the magics come from nv40_grctx.c */
+		if      (dev_priv->chipset == 0x40) rsvd = 0x6aa0 * vs;
+		else if (dev_priv->chipset  < 0x43) rsvd = 0x4f00 * vs;
+		else if (nv44_graph_class(dev))	    rsvd = 0x4980 * vs;
+		else				    rsvd = 0x4a40 * vs;
+		rsvd += 16 * 1024;
+		rsvd *= dev_priv->engine.fifo.channels;
+
+		/* pciegart table */
+		if (drm_pci_device_is_pcie(dev))
+			rsvd += 512 * 1024;
+
+		/* object storage */
+		rsvd += 512 * 1024;
+
+		dev_priv->ramin_rsvd_vram = round_up(rsvd, 4096);
+	} else {
+		dev_priv->ramin_rsvd_vram = 512 * 1024;
+	}
 
 	ret = dev_priv->engine.vram.init(dev);
 	if (ret)

drivers/gpu/drm/nouveau/nouveau_sgdma.c

@@ -427,8 +427,7 @@ nouveau_sgdma_init(struct drm_device *dev)
 	u32 aper_size, align;
 	int ret;
 
-	if (dev_priv->card_type >= NV_50 ||
-	    dev_priv->ramin_rsvd_vram >= 2 * 1024 * 1024)
+	if (dev_priv->card_type >= NV_50 || drm_pci_device_is_pcie(dev))
 		aper_size = 512 * 1024 * 1024;
 	else
 		aper_size = 64 * 1024 * 1024;