From bdd43cb39f1b1e897c5d7992d05d0b9f0dd786d1 Mon Sep 17 00:00:00 2001
From: Michal Nazarewicz <mina86@mina86.com>
Date: Wed, 5 Sep 2012 07:50:41 +0200
Subject: drivers: dma-contiguous: refactor dma_alloc_from_contiguous()

The dma_alloc_from_contiguous() function returns either a valid pointer
to a page structure or NULL, the error code set when pageno >= cma->count
is not used at all and can be safely removed.

This commit also changes the function to avoid goto and have only one exit
path and one place where mutex is unlocked.

Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
[fixed compilation break caused by missing semicolon]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
index 34d94c7..9a14694 100644
--- a/drivers/base/dma-contiguous.c
+++ b/drivers/base/dma-contiguous.c
@@ -315,6 +315,7 @@ struct page *dma_alloc_from_contiguous(struct device *dev, int count,
 {
 	unsigned long mask, pfn, pageno, start = 0;
 	struct cma *cma = dev_get_cma_area(dev);
+	struct page *page = NULL;
 	int ret;
 
 	if (!cma || !cma->count)
@@ -336,18 +337,17 @@ struct page *dma_alloc_from_contiguous(struct device *dev, int count,
 	for (;;) {
 		pageno = bitmap_find_next_zero_area(cma->bitmap, cma->count,
 						    start, count, mask);
-		if (pageno >= cma->count) {
-			ret = -ENOMEM;
-			goto error;
-		}
+		if (pageno >= cma->count)
+			break;
 
 		pfn = cma->base_pfn + pageno;
 		ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA);
 		if (ret == 0) {
 			bitmap_set(cma->bitmap, pageno, count);
+			page = pfn_to_page(pfn);
 			break;
 		} else if (ret != -EBUSY) {
-			goto error;
+			break;
 		}
 		pr_debug("%s(): memory range at %p is busy, retrying\n",
 			 __func__, pfn_to_page(pfn));
@@ -356,12 +356,8 @@ struct page *dma_alloc_from_contiguous(struct device *dev, int count,
 	}
 
 	mutex_unlock(&cma_mutex);
-
-	pr_debug("%s(): returned %p\n", __func__, pfn_to_page(pfn));
-	return pfn_to_page(pfn);
-error:
-	mutex_unlock(&cma_mutex);
-	return NULL;
+	pr_debug("%s(): returned %p\n", __func__, page);
+	return page;
 }
 
 /**
-- 
cgit v0.10.2


From 5a796eeb7bbacc628044b12a2d000167ddbabec8 Mon Sep 17 00:00:00 2001
From: Hiroshi Doyu <hdoyu@nvidia.com>
Date: Tue, 11 Sep 2012 07:39:39 +0200
Subject: ARM: dma-mapping: Small logical clean up

Skip unnecessary operations if order == 0. A little bit easier to
read.

Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 13f555d..c390cea 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1012,11 +1012,12 @@ static struct page **__iommu_alloc_buffer(struct device *dev, size_t size, gfp_t
 		if (!pages[i])
 			goto error;
 
-		if (order)
+		if (order) {
 			split_page(pages[i], order);
-		j = 1 << order;
-		while (--j)
-			pages[i + j] = pages[i] + j;
+			j = 1 << order;
+			while (--j)
+				pages[i + j] = pages[i] + j;
+		}
 
 		__dma_clear_buffer(pages[i], PAGE_SIZE << order);
 		i += 1 << order;
-- 
cgit v0.10.2


From 75c5971614932ca53009cbbdfd6c8f96eab9e46f Mon Sep 17 00:00:00 2001
From: Hiroshi Doyu <hdoyu@nvidia.com>
Date: Tue, 11 Sep 2012 07:39:48 +0200
Subject: ARM: dma-mapping: Refrain noisy console message

With many IOMMU'able devices, console gets noisy.

Tegra30 has a few dozen of IOMMU'able devices.

Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index c390cea..3819f02 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1666,7 +1666,7 @@ int arm_iommu_attach_device(struct device *dev,
 	dev->archdata.mapping = mapping;
 	set_dma_ops(dev, &iommu_ops);
 
-	pr_info("Attached IOMMU controller to %s device.\n", dev_name(dev));
+	pr_debug("Attached IOMMU controller to %s device.\n", dev_name(dev));
 	return 0;
 }
 
-- 
cgit v0.10.2