arm: dma-mapping: remove order parameter from arm_iommu_create_mapping()

The 'order' parameter for IOMMU-aware dma-mapping implementation was
introduced mainly as a hack to reduce size of the bitmap used for
tracking IO virtual address space. Since now it is possible to dynamically
resize the bitmap, this hack is not needed and can be removed without any
impact on the client devices. This way the parameters for
arm_iommu_create_mapping() becomes much easier to understand. 'size'
parameter now means the maximum supported IO address space size.

The code will allocate (resize) bitmap in chunks, ensuring that a single
chunk is not larger than a single memory page to avoid unreliable
allocations of size larger than PAGE_SIZE in atomic context.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

4 files changed, 3 insertions, 8 deletions

diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.h b/drivers/gpu/drm/exynos/exynos_drm_drv.h
index 0eaf5a2..a8f9dba 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_drv.h
+++ b/drivers/gpu/drm/exynos/exynos_drm_drv.h
@@ -237,7 +237,6 @@ struct drm_exynos_file_private {
  *	otherwise default one.
  * @da_space_size: size of device address space.
  *	if 0 then default value is used for it.
- * @da_space_order: order to device address space.
  */
 struct exynos_drm_private {
 	struct drm_fb_helper *fb_helper;
@@ -255,7 +254,6 @@ struct exynos_drm_private {
 
 	unsigned long da_start;
 	unsigned long da_space_size;
-	unsigned long da_space_order;
 };
 
 /*
diff --git a/drivers/gpu/drm/exynos/exynos_drm_iommu.c b/drivers/gpu/drm/exynos/exynos_drm_iommu.c
index fb8db03..b32b291 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_iommu.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_iommu.c
@@ -36,12 +36,10 @@ int drm_create_iommu_mapping(struct drm_device *drm_dev)
 		priv->da_start = EXYNOS_DEV_ADDR_START;
 	if (!priv->da_space_size)
 		priv->da_space_size = EXYNOS_DEV_ADDR_SIZE;
-	if (!priv->da_space_order)
-		priv->da_space_order = EXYNOS_DEV_ADDR_ORDER;
 
 	mapping = arm_iommu_create_mapping(&platform_bus_type, priv->da_start,
-						priv->da_space_size,
-						priv->da_space_order);
+						priv->da_space_size);
+
 	if (IS_ERR(mapping))
 		return PTR_ERR(mapping);
 
diff --git a/drivers/gpu/drm/exynos/exynos_drm_iommu.h b/drivers/gpu/drm/exynos/exynos_drm_iommu.h
index 598e60f..72376d4 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_iommu.h
+++ b/drivers/gpu/drm/exynos/exynos_drm_iommu.h
@@ -14,7 +14,6 @@
 
 #define EXYNOS_DEV_ADDR_START	0x20000000
 #define EXYNOS_DEV_ADDR_SIZE	0x40000000
-#define EXYNOS_DEV_ADDR_ORDER	0x0
 
 #ifdef CONFIG_DRM_EXYNOS_IOMMU
 
diff --git a/drivers/iommu/shmobile-iommu.c b/drivers/iommu/shmobile-iommu.c
index 7a3b928..464acda 100644
--- a/drivers/iommu/shmobile-iommu.c
+++ b/drivers/iommu/shmobile-iommu.c
@@ -343,7 +343,7 @@ static int shmobile_iommu_add_device(struct device *dev)
 	mapping = archdata->iommu_mapping;
 	if (!mapping) {
 		mapping = arm_iommu_create_mapping(&platform_bus_type, 0,
-						   L1_LEN << 20, 0);
+						   L1_LEN << 20);
 		if (IS_ERR(mapping))
 			return PTR_ERR(mapping);
 		archdata->iommu_mapping = mapping;