[PATCH 4/9] drm/exynos: split buffer allocation using DMA mapping API on non-iommu

[Joonyoung Shim]

This introduces new functions to allocate/free buffer using DMA mapping
API. Now already exynos-drm uses DMA mapping API to allocate/free buffer
but it is used on both iommu and non-iommu, so split it. It will be
added new buffer allocation not to use DMA mapping API later.

Signed-off-by: Joonyoung Shim <jy0922.shim at samsung.com>
---
 drivers/gpu/drm/exynos/exynos_drm_gem.c | 90 +++++++++++++++++++++++----------
 1 file changed, 64 insertions(+), 26 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c
index d5951f75c774..88196edd4ade 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_gem.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
@@ -20,6 +20,63 @@
 #include "exynos_drm_gem.h"
 #include "exynos_drm_iommu.h"
 
+static int exynos_drm_alloc_dma(struct exynos_drm_gem *exynos_gem)
+{
+	struct drm_device *dev = exynos_gem->base.dev;
+	unsigned int nr_pages;
+	unsigned int i;
+	dma_addr_t addr;
+
+	init_dma_attrs(&exynos_gem->dma_attrs);
+
+	if (exynos_gem->flags & EXYNOS_BO_WC ||
+			!(exynos_gem->flags & EXYNOS_BO_CACHABLE))
+		dma_set_attr(DMA_ATTR_WRITE_COMBINE, &exynos_gem->dma_attrs);
+
+	dma_set_attr(DMA_ATTR_NO_KERNEL_MAPPING, &exynos_gem->dma_attrs);
+
+	nr_pages = exynos_gem->size >> PAGE_SHIFT;
+
+	exynos_gem->pages = drm_calloc_large(nr_pages, sizeof(struct page *));
+	if (!exynos_gem->pages) {
+		DRM_ERROR("failed to allocate pages\n");
+		return -ENOMEM;
+	}
+
+	exynos_gem->cookie = dma_alloc_attrs(dev->dev, exynos_gem->size,
+					     &exynos_gem->dma_addr, GFP_KERNEL,
+					     &exynos_gem->dma_attrs);
+	if (!exynos_gem->cookie) {
+		DRM_ERROR("failed to allocate buffer\n");
+		drm_free_large(exynos_gem->pages);
+		return -ENOMEM;
+	}
+
+	addr = exynos_gem->dma_addr;
+	for (i = 0; i < nr_pages; i++) {
+		exynos_gem->pages[i] =
+			pfn_to_page(dma_to_pfn(dev->dev, addr));
+		addr += PAGE_SIZE;
+	}
+
+	DRM_DEBUG_KMS("dma_addr(0x%lx), size(0x%lx)\n",
+			(unsigned long)exynos_gem->dma_addr, exynos_gem->size);
+
+	return 0;
+}
+
+static void exynos_drm_free_dma(struct exynos_drm_gem *exynos_gem)
+{
+	struct drm_device *dev = exynos_gem->base.dev;
+
+	DRM_DEBUG_KMS("dma_addr(0x%lx), size(0x%lx)\n",
+			(unsigned long)exynos_gem->dma_addr, exynos_gem->size);
+
+	dma_free_attrs(dev->dev, exynos_gem->size, exynos_gem->cookie,
+			exynos_gem->dma_addr, &exynos_gem->dma_attrs);
+	drm_free_large(exynos_gem->pages);
+}
+
 static int exynos_drm_alloc_buf(struct exynos_drm_gem *exynos_gem)
 {
 	struct drm_device *dev = exynos_gem->base.dev;
@@ -31,6 +88,9 @@ static int exynos_drm_alloc_buf(struct exynos_drm_gem *exynos_gem)
 		return 0;
 	}
 
+	if (!is_drm_iommu_supported(dev))
+		return exynos_drm_alloc_dma(exynos_gem);
+
 	init_dma_attrs(&exynos_gem->dma_attrs);
 
 	/*
@@ -51,15 +111,6 @@ static int exynos_drm_alloc_buf(struct exynos_drm_gem *exynos_gem)
 
 	nr_pages = exynos_gem->size >> PAGE_SHIFT;
 
-	if (!is_drm_iommu_supported(dev)) {
-		exynos_gem->pages = drm_calloc_large(nr_pages,
-						     sizeof(struct page *));
-		if (!exynos_gem->pages) {
-			DRM_ERROR("failed to allocate pages.\n");
-			return -ENOMEM;
-		}
-	}
-
 	exynos_gem->cookie = dma_alloc_attrs(dev->dev, exynos_gem->size,
 					     &exynos_gem->dma_addr, GFP_KERNEL,
 					     &exynos_gem->dma_attrs);
@@ -70,20 +121,7 @@ static int exynos_drm_alloc_buf(struct exynos_drm_gem *exynos_gem)
 		return -ENOMEM;
 	}
 
-	if (exynos_gem->pages) {
-		dma_addr_t start_addr;
-		unsigned int i = 0;
-
-		start_addr = exynos_gem->dma_addr;
-		while (i < nr_pages) {
-			exynos_gem->pages[i] =
-				pfn_to_page(dma_to_pfn(dev->dev, start_addr));
-			start_addr += PAGE_SIZE;
-			i++;
-		}
-	} else {
-		exynos_gem->pages = exynos_gem->cookie;
-	}
+	exynos_gem->pages = exynos_gem->cookie;
 
 	DRM_DEBUG_KMS("dma_addr(0x%lx), size(0x%lx)\n",
 			(unsigned long)exynos_gem->dma_addr, exynos_gem->size);
@@ -100,15 +138,15 @@ static void exynos_drm_free_buf(struct exynos_drm_gem *exynos_gem)
 		return;
 	}
 
+	if (!is_drm_iommu_supported(dev))
+		return exynos_drm_free_dma(exynos_gem);
+
 	DRM_DEBUG_KMS("dma_addr(0x%lx), size(0x%lx)\n",
 			(unsigned long)exynos_gem->dma_addr, exynos_gem->size);
 
 	dma_free_attrs(dev->dev, exynos_gem->size, exynos_gem->cookie,
 			(dma_addr_t)exynos_gem->dma_addr,
 			&exynos_gem->dma_attrs);
-
-	if (!is_drm_iommu_supported(dev))
-		drm_free_large(exynos_gem->pages);
 }
 
 static int exynos_drm_gem_handle_create(struct drm_gem_object *obj,
-- 
1.9.1