dma-mapping: use unsigned long for dma_attrs

The dma-mapping core and the implementations do not change the DMA
attributes passed by pointer.  Thus the pointer can point to const data.
However the attributes do not have to be a bitfield.  Instead unsigned
long will do fine:

1. This is just simpler.  Both in terms of reading the code and setting
   attributes.  Instead of initializing local attributes on the stack
   and passing pointer to it to dma_set_attr(), just set the bits.

2. It brings safeness and checking for const correctness because the
   attributes are passed by value.

Semantic patches for this change (at least most of them):

    virtual patch
    virtual context

    @r@
    identifier f, attrs;

    @@
    f(...,
    - struct dma_attrs *attrs
    + unsigned long attrs
    , ...)
    {
    ...
    }

    @@
    identifier r.f;
    @@
    f(...,
    - NULL
    + 0
     )

and

    // Options: --all-includes
    virtual patch
    virtual context

    @r@
    identifier f, attrs;
    type t;

    @@
    t f(..., struct dma_attrs *attrs);

    @@
    identifier r.f;
    @@
    f(...,
    - NULL
    + 0
     )

Link: http://lkml.kernel.org/r/1468399300-5399-2-git-send-email-k.kozlowski@samsung.com
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no>
Acked-by: Mark Salter <msalter@redhat.com> [c6x]
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> [cris]
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> [drm]
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Acked-by: Joerg Roedel <jroedel@suse.de> [iommu]
Acked-by: Fabien Dessenne <fabien.dessenne@st.com> [bdisp]
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com> [vb2-core]
Acked-by: David Vrabel <david.vrabel@citrix.com> [xen]
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> [xen swiotlb]
Acked-by: Joerg Roedel <jroedel@suse.de> [iommu]
Acked-by: Richard Kuo <rkuo@codeaurora.org> [hexagon]
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k]
Acked-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> [s390]
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no> [avr32]
Acked-by: Vineet Gupta <vgupta@synopsys.com> [arc]
Acked-by: Robin Murphy <robin.murphy@arm.com> [arm64 and dma-iommu]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 14 insertions, 14 deletions

diff --git a/arch/powerpc/platforms/cell/iommu.c b/arch/powerpc/platforms/cell/iommu.c
index 9027d7c48507..f7d1a4953ea0 100644
--- a/arch/powerpc/platforms/cell/iommu.c
+++ b/arch/powerpc/platforms/cell/iommu.c
@@ -166,7 +166,7 @@ static void invalidate_tce_cache(struct cbe_iommu *iommu, unsigned long *pte,
 
 static int tce_build_cell(struct iommu_table *tbl, long index, long npages,
 		unsigned long uaddr, enum dma_data_direction direction,
-		struct dma_attrs *attrs)
+		unsigned long attrs)
 {
 	int i;
 	unsigned long *io_pte, base_pte;
@@ -193,7 +193,7 @@ static int tce_build_cell(struct iommu_table *tbl, long index, long npages,
 	base_pte = CBE_IOPTE_PP_W | CBE_IOPTE_PP_R | CBE_IOPTE_M |
 		CBE_IOPTE_SO_RW | (window->ioid & CBE_IOPTE_IOID_Mask);
 #endif
-	if (unlikely(dma_get_attr(DMA_ATTR_WEAK_ORDERING, attrs)))
+	if (unlikely(attrs & DMA_ATTR_WEAK_ORDERING))
 		base_pte &= ~CBE_IOPTE_SO_RW;
 
 	io_pte = (unsigned long *)tbl->it_base + (index - tbl->it_offset);
@@ -526,7 +526,7 @@ cell_iommu_setup_window(struct cbe_iommu *iommu, struct device_node *np,
 
 	__set_bit(0, window->table.it_map);
 	tce_build_cell(&window->table, window->table.it_offset, 1,
-		       (unsigned long)iommu->pad_page, DMA_TO_DEVICE, NULL);
+		       (unsigned long)iommu->pad_page, DMA_TO_DEVICE, 0);
 
 	return window;
 }
@@ -572,7 +572,7 @@ static struct iommu_table *cell_get_iommu_table(struct device *dev)
 
 static void *dma_fixed_alloc_coherent(struct device *dev, size_t size,
 				      dma_addr_t *dma_handle, gfp_t flag,
-				      struct dma_attrs *attrs)
+				      unsigned long attrs)
 {
 	if (iommu_fixed_is_weak)
 		return iommu_alloc_coherent(dev, cell_get_iommu_table(dev),
@@ -586,7 +586,7 @@ static void *dma_fixed_alloc_coherent(struct device *dev, size_t size,
 
 static void dma_fixed_free_coherent(struct device *dev, size_t size,
 				    void *vaddr, dma_addr_t dma_handle,
-				    struct dma_attrs *attrs)
+				    unsigned long attrs)
 {
 	if (iommu_fixed_is_weak)
 		iommu_free_coherent(cell_get_iommu_table(dev), size, vaddr,
@@ -598,9 +598,9 @@ static void dma_fixed_free_coherent(struct device *dev, size_t size,
 static dma_addr_t dma_fixed_map_page(struct device *dev, struct page *page,
 				     unsigned long offset, size_t size,
 				     enum dma_data_direction direction,
-				     struct dma_attrs *attrs)
+				     unsigned long attrs)
 {
-	if (iommu_fixed_is_weak == dma_get_attr(DMA_ATTR_WEAK_ORDERING, attrs))
+	if (iommu_fixed_is_weak == (attrs & DMA_ATTR_WEAK_ORDERING))
 		return dma_direct_ops.map_page(dev, page, offset, size,
 					       direction, attrs);
 	else
@@ -611,9 +611,9 @@ static dma_addr_t dma_fixed_map_page(struct device *dev, struct page *page,
 
 static void dma_fixed_unmap_page(struct device *dev, dma_addr_t dma_addr,
 				 size_t size, enum dma_data_direction direction,
-				 struct dma_attrs *attrs)
+				 unsigned long attrs)
 {
-	if (iommu_fixed_is_weak == dma_get_attr(DMA_ATTR_WEAK_ORDERING, attrs))
+	if (iommu_fixed_is_weak == (attrs & DMA_ATTR_WEAK_ORDERING))
 		dma_direct_ops.unmap_page(dev, dma_addr, size, direction,
 					  attrs);
 	else
@@ -623,9 +623,9 @@ static void dma_fixed_unmap_page(struct device *dev, dma_addr_t dma_addr,
 
 static int dma_fixed_map_sg(struct device *dev, struct scatterlist *sg,
 			   int nents, enum dma_data_direction direction,
-			   struct dma_attrs *attrs)
+			   unsigned long attrs)
 {
-	if (iommu_fixed_is_weak == dma_get_attr(DMA_ATTR_WEAK_ORDERING, attrs))
+	if (iommu_fixed_is_weak == (attrs & DMA_ATTR_WEAK_ORDERING))
 		return dma_direct_ops.map_sg(dev, sg, nents, direction, attrs);
 	else
 		return ppc_iommu_map_sg(dev, cell_get_iommu_table(dev), sg,
@@ -635,9 +635,9 @@ static int dma_fixed_map_sg(struct device *dev, struct scatterlist *sg,
 
 static void dma_fixed_unmap_sg(struct device *dev, struct scatterlist *sg,
 			       int nents, enum dma_data_direction direction,
-			       struct dma_attrs *attrs)
+			       unsigned long attrs)
 {
-	if (iommu_fixed_is_weak == dma_get_attr(DMA_ATTR_WEAK_ORDERING, attrs))
+	if (iommu_fixed_is_weak == (attrs & DMA_ATTR_WEAK_ORDERING))
 		dma_direct_ops.unmap_sg(dev, sg, nents, direction, attrs);
 	else
 		ppc_iommu_unmap_sg(cell_get_iommu_table(dev), sg, nents,
@@ -1162,7 +1162,7 @@ static int __init setup_iommu_fixed(char *str)
 	pciep = of_find_node_by_type(NULL, "pcie-endpoint");
 
 	if (strcmp(str, "weak") == 0 || (pciep && strcmp(str, "strong") != 0))
-		iommu_fixed_is_weak = 1;
+		iommu_fixed_is_weak = DMA_ATTR_WEAK_ORDERING;
 
 	of_node_put(pciep);