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>

4 files changed, 17 insertions, 19 deletions

diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
index fb49443..4cfb39d 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
@@ -52,7 +52,7 @@ static int exynos_drm_fb_mmap(struct fb_info *info,
 
 	ret = dma_mmap_attrs(to_dma_dev(helper->dev), vma, exynos_gem->cookie,
 			     exynos_gem->dma_addr, exynos_gem->size,
-			     &exynos_gem->dma_attrs);
+			     exynos_gem->dma_attrs);
 	if (ret < 0) {
 		DRM_ERROR("failed to mmap.\n");
 		return ret;
diff --git a/drivers/gpu/drm/exynos/exynos_drm_g2d.c b/drivers/gpu/drm/exynos/exynos_drm_g2d.c
index 8564c3d..4bf00f5 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_g2d.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_g2d.c
@@ -17,7 +17,6 @@
 #include <linux/slab.h>
 #include <linux/workqueue.h>
 #include <linux/dma-mapping.h>
-#include <linux/dma-attrs.h>
 #include <linux/of.h>
 
 #include <drm/drmP.h>
@@ -235,7 +234,7 @@ struct g2d_data {
 	struct mutex			cmdlist_mutex;
 	dma_addr_t			cmdlist_pool;
 	void				*cmdlist_pool_virt;
-	struct dma_attrs		cmdlist_dma_attrs;
+	unsigned long			cmdlist_dma_attrs;
 
 	/* runqueue*/
 	struct g2d_runqueue_node	*runqueue_node;
@@ -256,13 +255,12 @@ static int g2d_init_cmdlist(struct g2d_data *g2d)
 	int ret;
 	struct g2d_buf_info *buf_info;
 
-	init_dma_attrs(&g2d->cmdlist_dma_attrs);
-	dma_set_attr(DMA_ATTR_WRITE_COMBINE, &g2d->cmdlist_dma_attrs);
+	g2d->cmdlist_dma_attrs = DMA_ATTR_WRITE_COMBINE;
 
 	g2d->cmdlist_pool_virt = dma_alloc_attrs(to_dma_dev(subdrv->drm_dev),
 						G2D_CMDLIST_POOL_SIZE,
 						&g2d->cmdlist_pool, GFP_KERNEL,
-						&g2d->cmdlist_dma_attrs);
+						g2d->cmdlist_dma_attrs);
 	if (!g2d->cmdlist_pool_virt) {
 		dev_err(dev, "failed to allocate dma memory\n");
 		return -ENOMEM;
@@ -295,7 +293,7 @@ static int g2d_init_cmdlist(struct g2d_data *g2d)
 err:
 	dma_free_attrs(to_dma_dev(subdrv->drm_dev), G2D_CMDLIST_POOL_SIZE,
 			g2d->cmdlist_pool_virt,
-			g2d->cmdlist_pool, &g2d->cmdlist_dma_attrs);
+			g2d->cmdlist_pool, g2d->cmdlist_dma_attrs);
 	return ret;
 }
 
@@ -309,7 +307,7 @@ static void g2d_fini_cmdlist(struct g2d_data *g2d)
 		dma_free_attrs(to_dma_dev(subdrv->drm_dev),
 				G2D_CMDLIST_POOL_SIZE,
 				g2d->cmdlist_pool_virt,
-				g2d->cmdlist_pool, &g2d->cmdlist_dma_attrs);
+				g2d->cmdlist_pool, g2d->cmdlist_dma_attrs);
 	}
 }
 
diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c
index cdf9f1a..f2ae72b 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_gem.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
@@ -24,7 +24,7 @@
 static int exynos_drm_alloc_buf(struct exynos_drm_gem *exynos_gem)
 {
 	struct drm_device *dev = exynos_gem->base.dev;
-	enum dma_attr attr;
+	unsigned long attr;
 	unsigned int nr_pages;
 	struct sg_table sgt;
 	int ret = -ENOMEM;
@@ -34,7 +34,7 @@ static int exynos_drm_alloc_buf(struct exynos_drm_gem *exynos_gem)
 		return 0;
 	}
 
-	init_dma_attrs(&exynos_gem->dma_attrs);
+	exynos_gem->dma_attrs = 0;
 
 	/*
 	 * if EXYNOS_BO_CONTIG, fully physically contiguous memory
@@ -42,7 +42,7 @@ static int exynos_drm_alloc_buf(struct exynos_drm_gem *exynos_gem)
 	 * as possible.
 	 */
 	if (!(exynos_gem->flags & EXYNOS_BO_NONCONTIG))
-		dma_set_attr(DMA_ATTR_FORCE_CONTIGUOUS, &exynos_gem->dma_attrs);
+		exynos_gem->dma_attrs |= DMA_ATTR_FORCE_CONTIGUOUS;
 
 	/*
 	 * if EXYNOS_BO_WC or EXYNOS_BO_NONCACHABLE, writecombine mapping
@@ -54,8 +54,8 @@ static int exynos_drm_alloc_buf(struct exynos_drm_gem *exynos_gem)
 	else
 		attr = DMA_ATTR_NON_CONSISTENT;
 
-	dma_set_attr(attr, &exynos_gem->dma_attrs);
-	dma_set_attr(DMA_ATTR_NO_KERNEL_MAPPING, &exynos_gem->dma_attrs);
+	exynos_gem->dma_attrs |= attr;
+	exynos_gem->dma_attrs |= DMA_ATTR_NO_KERNEL_MAPPING;
 
 	nr_pages = exynos_gem->size >> PAGE_SHIFT;
 
@@ -67,7 +67,7 @@ static int exynos_drm_alloc_buf(struct exynos_drm_gem *exynos_gem)
 
 	exynos_gem->cookie = dma_alloc_attrs(to_dma_dev(dev), exynos_gem->size,
 					     &exynos_gem->dma_addr, GFP_KERNEL,
-					     &exynos_gem->dma_attrs);
+					     exynos_gem->dma_attrs);
 	if (!exynos_gem->cookie) {
 		DRM_ERROR("failed to allocate buffer.\n");
 		goto err_free;
@@ -75,7 +75,7 @@ static int exynos_drm_alloc_buf(struct exynos_drm_gem *exynos_gem)
 
 	ret = dma_get_sgtable_attrs(to_dma_dev(dev), &sgt, exynos_gem->cookie,
 				    exynos_gem->dma_addr, exynos_gem->size,
-				    &exynos_gem->dma_attrs);
+				    exynos_gem->dma_attrs);
 	if (ret < 0) {
 		DRM_ERROR("failed to get sgtable.\n");
 		goto err_dma_free;
@@ -99,7 +99,7 @@ err_sgt_free:
 	sg_free_table(&sgt);
 err_dma_free:
 	dma_free_attrs(to_dma_dev(dev), exynos_gem->size, exynos_gem->cookie,
-		       exynos_gem->dma_addr, &exynos_gem->dma_attrs);
+		       exynos_gem->dma_addr, exynos_gem->dma_attrs);
 err_free:
 	drm_free_large(exynos_gem->pages);
 
@@ -120,7 +120,7 @@ static void exynos_drm_free_buf(struct exynos_drm_gem *exynos_gem)
 
 	dma_free_attrs(to_dma_dev(dev), exynos_gem->size, exynos_gem->cookie,
 			(dma_addr_t)exynos_gem->dma_addr,
-			&exynos_gem->dma_attrs);
+			exynos_gem->dma_attrs);
 
 	drm_free_large(exynos_gem->pages);
 }
@@ -346,7 +346,7 @@ static int exynos_drm_gem_mmap_buffer(struct exynos_drm_gem *exynos_gem,
 
 	ret = dma_mmap_attrs(to_dma_dev(drm_dev), vma, exynos_gem->cookie,
 			     exynos_gem->dma_addr, exynos_gem->size,
-			     &exynos_gem->dma_attrs);
+			     exynos_gem->dma_attrs);
 	if (ret < 0) {
 		DRM_ERROR("failed to mmap.\n");
 		return ret;
diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.h b/drivers/gpu/drm/exynos/exynos_drm_gem.h
index 7810074..df7c543 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_gem.h
+++ b/drivers/gpu/drm/exynos/exynos_drm_gem.h
@@ -50,7 +50,7 @@ struct exynos_drm_gem {
 	void			*cookie;
 	void __iomem		*kvaddr;
 	dma_addr_t		dma_addr;
-	struct dma_attrs	dma_attrs;
+	unsigned long		dma_attrs;
 	struct page		**pages;
 	struct sg_table		*sgt;
 };