[PATCH v5] drm/nouveau: map pages using DMA API

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

The DMA API is the recommended way to map pages no matter what the
underlying bus is. Use the DMA functions for page mapping and remove
currently existing wrappers.

Signed-off-by: Alexandre Courbot <acourbot-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
Cc: Daniel Vetter <daniel-/w4YWyX8dFk@public.gmane.org>
---
Changes since v4:
- Patch against the Nouveau tree instead of the kernel
- Separated this patch from the rest of the series since it can be
  merged alone
- Replaced all pci_map invokations with dma_map. As Daniel pointed
  out, using the PCI API is deprecated:
Documentation/DMA-API-HOWTO.txt:

"Note that the DMA API works with any bus independent of the underlying
microprocessor architecture. You should use the DMA API rather than the
bus-specific DMA API, i.e., use the dma_map_*() interfaces rather than the
pci_map_*() interfaces."
- As a result, removed the page mapping wrappers which have become
  unneeded.

 drm/nouveau_bo.c           | 22 ++++++++++++++++------
 lib/core/os.h              |  8 ++++----
 nvkm/engine/device/base.c  | 25 -------------------------
 nvkm/include/core/device.h |  6 ------
 nvkm/subdev/fb/nv50.c      |  7 +++++--
 nvkm/subdev/fb/nvc0.c      |  7 +++++--
 6 files changed, 30 insertions(+), 45 deletions(-)

diff --git a/drm/nouveau_bo.c b/drm/nouveau_bo.c
index 4db886f9f793..e4f2071c46c3 100644
--- a/drm/nouveau_bo.c
+++ b/drm/nouveau_bo.c
@@ -1340,6 +1340,7 @@ nouveau_ttm_tt_populate(struct ttm_tt *ttm)
 	struct nouveau_drm *drm;
 	struct nouveau_device *device;
 	struct drm_device *dev;
+	struct device *pdev;
 	unsigned i;
 	int r;
 	bool slave = !!(ttm->page_flags & TTM_PAGE_FLAG_SG);
@@ -1358,6 +1359,7 @@ nouveau_ttm_tt_populate(struct ttm_tt *ttm)
 	drm = nouveau_bdev(ttm->bdev);
 	device = nv_device(drm->device);
 	dev = drm->dev;
+	pdev = nv_device_base(device);
 
 #if __OS_HAS_AGP
 	if (drm->agp.stat == ENABLED) {
@@ -1377,17 +1379,22 @@ nouveau_ttm_tt_populate(struct ttm_tt *ttm)
 	}
 
 	for (i = 0; i < ttm->num_pages; i++) {
-		ttm_dma->dma_address[i] = nv_device_map_page(device,
-							     ttm->pages[i]);
-		if (!ttm_dma->dma_address[i]) {
+		dma_addr_t addr;
+
+		addr = dma_map_page(pdev, ttm->pages[i], 0, PAGE_SIZE,
+				    DMA_BIDIRECTIONAL);
+
+		if (dma_mapping_error(pdev, addr)) {
 			while (--i) {
-				nv_device_unmap_page(device,
-						     ttm_dma->dma_address[i]);
+				dma_unmap_page(pdev, ttm_dma->dma_address[i],
+					       PAGE_SIZE, DMA_BIDIRECTIONAL);
 				ttm_dma->dma_address[i] = 0;
 			}
 			ttm_pool_unpopulate(ttm);
 			return -EFAULT;
 		}
+
+		ttm_dma->dma_address[i] = addr;
 	}
 	return 0;
 }
@@ -1399,6 +1406,7 @@ nouveau_ttm_tt_unpopulate(struct ttm_tt *ttm)
 	struct nouveau_drm *drm;
 	struct nouveau_device *device;
 	struct drm_device *dev;
+	struct device *pdev;
 	unsigned i;
 	bool slave = !!(ttm->page_flags & TTM_PAGE_FLAG_SG);
 
@@ -1408,6 +1416,7 @@ nouveau_ttm_tt_unpopulate(struct ttm_tt *ttm)
 	drm = nouveau_bdev(ttm->bdev);
 	device = nv_device(drm->device);
 	dev = drm->dev;
+	pdev = nv_device_base(device);
 
 #if __OS_HAS_AGP
 	if (drm->agp.stat == ENABLED) {
@@ -1425,7 +1434,8 @@ nouveau_ttm_tt_unpopulate(struct ttm_tt *ttm)
 
 	for (i = 0; i < ttm->num_pages; i++) {
 		if (ttm_dma->dma_address[i]) {
-			nv_device_unmap_page(device, ttm_dma->dma_address[i]);
+			dma_unmap_page(pdev, ttm_dma->dma_address[i], PAGE_SIZE,
+				       DMA_BIDIRECTIONAL);
 		}
 	}
 
diff --git a/lib/core/os.h b/lib/core/os.h
index 5f4f04fbff3d..596e083ffb36 100644
--- a/lib/core/os.h
+++ b/lib/core/os.h
@@ -644,7 +644,7 @@ dma_free_coherent(struct device *dev, size_t sz, void *vaddr, dma_addr_t bus)
  *****************************************************************************/
 #include <pciaccess.h>
 
-#define PCI_DMA_BIDIRECTIONAL 1
+#define DMA_BIDIRECTIONAL 1
 
 #define PCI_CAP_ID_AGP 0x02
 
@@ -688,7 +688,7 @@ pci_resource_len(struct pci_dev *pdev, int bar)
 }
 
 static inline dma_addr_t
-pci_map_page(struct pci_dev *pdev, struct page *page, int offset,
+dma_map_page(struct device *pdev, struct page *page, int offset,
 	     int length, unsigned flags)
 {
 	return 0;
@@ -696,13 +696,13 @@ pci_map_page(struct pci_dev *pdev, struct page *page, int offset,
 
 
 static inline bool
-pci_dma_mapping_error(struct pci_dev *pdev, dma_addr_t addr)
+dma_mapping_error(struct device *pdev, dma_addr_t addr)
 {
 	return true;
 }
 
 static inline void
-pci_unmap_page(struct pci_dev *pdev, dma_addr_t addr, int size, unsigned flags)
+dma_unmap_page(struct device *pdev, dma_addr_t addr, int size, unsigned flags)
 {
 }
 
diff --git a/nvkm/engine/device/base.c b/nvkm/engine/device/base.c
index 466dda2f7a3a..6c16dabe13b3 100644
--- a/nvkm/engine/device/base.c
+++ b/nvkm/engine/device/base.c
@@ -487,31 +487,6 @@ nv_device_resource_len(struct nouveau_device *device, unsigned int bar)
 	}
 }
 
-dma_addr_t
-nv_device_map_page(struct nouveau_device *device, struct page *page)
-{
-	dma_addr_t ret;
-
-	if (nv_device_is_pci(device)) {
-		ret = pci_map_page(device->pdev, page, 0, PAGE_SIZE,
-				   PCI_DMA_BIDIRECTIONAL);
-		if (pci_dma_mapping_error(device->pdev, ret))
-			ret = 0;
-	} else {
-		ret = page_to_phys(page);
-	}
-
-	return ret;
-}
-
-void
-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);
-}
-
 int
 nv_device_get_irq(struct nouveau_device *device, bool stall)
 {
diff --git a/nvkm/include/core/device.h b/nvkm/include/core/device.h
index 9ce2ee9aa32e..03c039dcc61f 100644
--- a/nvkm/include/core/device.h
+++ b/nvkm/include/core/device.h
@@ -174,12 +174,6 @@ nv_device_resource_start(struct nouveau_device *device, unsigned int bar);
 resource_size_t
 nv_device_resource_len(struct nouveau_device *device, unsigned int bar);
 
-dma_addr_t
-nv_device_map_page(struct nouveau_device *device, struct page *page);
-
-void
-nv_device_unmap_page(struct nouveau_device *device, dma_addr_t addr);
-
 int
 nv_device_get_irq(struct nouveau_device *device, bool stall);
 
diff --git a/nvkm/subdev/fb/nv50.c b/nvkm/subdev/fb/nv50.c
index 1fc55c1e91a1..7d88e17fa927 100644
--- a/nvkm/subdev/fb/nv50.c
+++ b/nvkm/subdev/fb/nv50.c
@@ -250,7 +250,9 @@ nv50_fb_ctor(struct nouveau_object *parent, struct nouveau_object *engine,
 
 	priv->r100c08_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
 	if (priv->r100c08_page) {
-		priv->r100c08 = nv_device_map_page(device, priv->r100c08_page);
+		priv->r100c08 = dma_map_page(nv_device_base(device),
+					     priv->r100c08_page, 0, PAGE_SIZE,
+					     DMA_BIDIRECTIONAL);
 		if (!priv->r100c08)
 			nv_warn(priv, "failed 0x100c08 page map\n");
 	} else {
@@ -268,7 +270,8 @@ nv50_fb_dtor(struct nouveau_object *object)
 	struct nv50_fb_priv *priv = (void *)object;
 
 	if (priv->r100c08_page) {
-		nv_device_unmap_page(device, priv->r100c08);
+		dma_unmap_page(nv_device_base(device), priv->r100c08, PAGE_SIZE,
+			       DMA_BIDIRECTIONAL);
 		__free_page(priv->r100c08_page);
 	}
 
diff --git a/nvkm/subdev/fb/nvc0.c b/nvkm/subdev/fb/nvc0.c
index 0670ae33ee45..9f5f3ac8d4c6 100644
--- a/nvkm/subdev/fb/nvc0.c
+++ b/nvkm/subdev/fb/nvc0.c
@@ -70,7 +70,8 @@ nvc0_fb_dtor(struct nouveau_object *object)
 	struct nvc0_fb_priv *priv = (void *)object;
 
 	if (priv->r100c10_page) {
-		nv_device_unmap_page(device, priv->r100c10);
+		dma_unmap_page(nv_device_base(device), priv->r100c10, PAGE_SIZE,
+			       DMA_BIDIRECTIONAL);
 		__free_page(priv->r100c10_page);
 	}
 
@@ -93,7 +94,9 @@ nvc0_fb_ctor(struct nouveau_object *parent, struct nouveau_object *engine,
 
 	priv->r100c10_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
 	if (priv->r100c10_page) {
-		priv->r100c10 = nv_device_map_page(device, priv->r100c10_page);
+		priv->r100c10 = dma_map_page(nv_device_base(device),
+					     priv->r100c10_page, 0, PAGE_SIZE,
+					     DMA_BIDIRECTIONAL);
 		if (!priv->r100c10)
 			return -EFAULT;
 	}
-- 
2.0.3