Revert "drm/nouveau: set DMA mask before creating the flush page"

This reverts commit ebe755605082eddff80eafe0c50915b1366ee98f.

Tested the latest kernel on my GB203 and this seems to break it somehow.

Nov 09 04:16:14 bighp kernel: nouveau 0000:02:00.0: gsp: GSP-FMC boot failed (mbox: 0x0000000b)
Nov 09 04:16:14 bighp kernel: nouveau 0000:02:00.0: gsp: init failed, -5
Nov 09 04:16:14 bighp kernel: nouveau 0000:02:00.0: init failed with -5
Nov 09 04:16:14 bighp kernel: nouveau: drm:00000000:00000080: init failed with -5
Nov 09 04:16:14 bighp kernel: nouveau 0000:02:00.0: drm: Device allocation failed: -5
Nov 09 04:16:14 bighp kernel: nouveau 0000:02:00.0: probe with driver nouveau failed with error -5

Not sure why, I went over the patch and thought it should have worked, but there must be some
32-bit problem maybe in the FMC boot path.

Signed-off-by: Dave Airlie <[e-mail]>

drivers/gpu/drm/nouveau/nvkm/engine/device/pci.c

···
 	*pdevice = &pdev->device;
 	pdev->pdev = pci_dev;
 
-	/* Set DMA mask based on capabilities reported by the MMU subdev. */
-	if (pdev->device.mmu && !pdev->device.pci->agp.bridge)
-		bits = pdev->device.mmu->dma_bits;
-	else
-		bits = 32;
-
-	ret = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(bits));
-	if (ret && bits != 32) {
-		dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(32));
-		pdev->device.mmu->dma_bits = 32;
-	}
-
 	ret = nvkm_device_ctor(&nvkm_device_pci_func, quirk, &pci_dev->dev,
 			       pci_is_pcie(pci_dev) ? NVKM_DEVICE_PCIE :
 			       pci_find_capability(pci_dev, PCI_CAP_ID_AGP) ?
···
 
 	if (ret)
 		return ret;
+
+	/* Set DMA mask based on capabilities reported by the MMU subdev. */
+	if (pdev->device.mmu && !pdev->device.pci->agp.bridge)
+		bits = pdev->device.mmu->dma_bits;
+	else
+		bits = 32;
+
+	ret = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(bits));
+	if (ret && bits != 32) {
+		dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(32));
+		pdev->device.mmu->dma_bits = 32;
+	}
 
 	return 0;
 }