[PATCH v4 2/6] drm/nouveau: map pages using DMA API on platform devices

[Alexandre Courbot <acourbot-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>]

page_to_phys() is not the correct way to obtain the DMA address of a
buffer on a non-PCI system. Use the DMA API functions for this, which
are portable and will allow us to use other DMA API functions for
buffer synchronization.

Signed-off-by: Alexandre Courbot <acourbot-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
---
 drivers/gpu/drm/nouveau/core/engine/device/base.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/core/engine/device/base.c b/drivers/gpu/drm/nouveau/core/engine/device/base.c
index 18c8c7245b73..e4e9e64988fe 100644
--- a/drivers/gpu/drm/nouveau/core/engine/device/base.c
+++ b/drivers/gpu/drm/nouveau/core/engine/device/base.c
@@ -489,7 +489,10 @@ nv_device_map_page(struct nouveau_device *device, struct page *page)
 		if (pci_dma_mapping_error(device->pdev, ret))
 			ret = 0;
 	} else {
-		ret = page_to_phys(page);
+		ret = dma_map_page(&device->platformdev->dev, page, 0,
+				   PAGE_SIZE, DMA_BIDIRECTIONAL);
+		if (dma_mapping_error(&device->platformdev->dev, ret))
+			ret = 0;
 	}
 
 	return ret;
@@ -501,6 +504,9 @@ nv_device_unmap_page(struct nouveau_device *device, dma_addr_t addr)
 	if (nv_device_is_pci(device))
 		pci_unmap_page(device->pdev, addr, PAGE_SIZE,
 			       PCI_DMA_BIDIRECTIONAL);
+	else
+		dma_unmap_page(&device->platformdev->dev, addr,
+			       PAGE_SIZE, DMA_BIDIRECTIONAL);
 }
 
 int
-- 
2.0.0