Merge branch 'exynos-drm-next' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos into drm-next

   This pull request adds to the rework patch series for IOMMU
   integration to support ARM64bit architecture with DMA-IOMMU
   glue code.

   With this patch series, Exynos DRM works well on Exynos5433 SoC
   with IOMMU enabled.

* 'exynos-drm-next' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos:
  drm/exynos: iommu: add support for ARM64 specific code for IOMMU glue
  drm/exynos: iommu: move ARM specific code to exynos_drm_iommu.h
  drm/exynos: iommu: remove unused entries from exynos_drm_private strcuture
  drm/exynos: iommu: add a check if all sub-devices have iommu controller
  drm/exynos: iommu: move dma_params configuration code to separate functions

drivers/gpu/drm/exynos/Kconfig

@@ -11,7 +11,7 @@ if DRM_EXYNOS
 
 config DRM_EXYNOS_IOMMU
 	bool
-	depends on EXYNOS_IOMMU && ARM_DMA_USE_IOMMU
+	depends on EXYNOS_IOMMU
 	default y
 
 comment "CRTCs"

drivers/gpu/drm/exynos/exynos_drm_drv.c

@@ -159,12 +159,7 @@ static int exynos_drm_load(struct drm_device *dev, unsigned long flags)
 	DRM_INFO("Exynos DRM: using %s device for DMA mapping operations\n",
 		 dev_name(private->dma_dev));
 
-	/*
-	 * create mapping to manage iommu table and set a pointer to iommu
-	 * mapping structure to iommu_mapping of private data.
-	 * also this iommu_mapping can be used to check if iommu is supported
-	 * or not.
-	 */
+	/* create common IOMMU mapping for all devices attached to Exynos DRM */
 	ret = drm_create_iommu_mapping(dev);
 	if (ret < 0) {
 		DRM_ERROR("failed to create iommu mapping.\n");

drivers/gpu/drm/exynos/exynos_drm_drv.h

@@ -224,8 +224,6 @@ struct exynos_drm_private {
 	struct drm_property *plane_zpos_property;
 
 	struct device *dma_dev;
-	unsigned long da_start;
-	unsigned long da_space_size;
 	void *mapping;
 
 	unsigned int pipe;

drivers/gpu/drm/exynos/exynos_drm_iommu.c

@@ -14,13 +14,27 @@
 
 #include <linux/dma-mapping.h>
 #include <linux/iommu.h>
-#include <linux/kref.h>
-
-#include <asm/dma-iommu.h>
 
 #include "exynos_drm_drv.h"
 #include "exynos_drm_iommu.h"
 
+static inline int configure_dma_max_seg_size(struct device *dev)
+{
+	if (!dev->dma_parms)
+		dev->dma_parms = kzalloc(sizeof(*dev->dma_parms), GFP_KERNEL);
+	if (!dev->dma_parms)
+		return -ENOMEM;
+
+	dma_set_max_seg_size(dev, DMA_BIT_MASK(32));
+	return 0;
+}
+
+static inline void clear_dma_max_seg_size(struct device *dev)
+{
+	kfree(dev->dma_parms);
+	dev->dma_parms = NULL;
+}
+
 /*
  * drm_create_iommu_mapping - create a mapping structure
  *
@@ -28,38 +42,22 @@
  */
 int drm_create_iommu_mapping(struct drm_device *drm_dev)
 {
-	struct dma_iommu_mapping *mapping = NULL;
 	struct exynos_drm_private *priv = drm_dev->dev_private;
 
-	if (!priv->da_start)
-		priv->da_start = EXYNOS_DEV_ADDR_START;
-	if (!priv->da_space_size)
-		priv->da_space_size = EXYNOS_DEV_ADDR_SIZE;
-
-	mapping = arm_iommu_create_mapping(&platform_bus_type, priv->da_start,
-						priv->da_space_size);
-
-	if (IS_ERR(mapping))
-		return PTR_ERR(mapping);
-
-	priv->mapping = mapping;
-
-	return 0;
+	return __exynos_iommu_create_mapping(priv, EXYNOS_DEV_ADDR_START,
+					     EXYNOS_DEV_ADDR_SIZE);
 }
 
 /*
  * drm_release_iommu_mapping - release iommu mapping structure
  *
  * @drm_dev: DRM device
- *
- * if mapping->kref becomes 0 then all things related to iommu mapping
- * will be released
  */
 void drm_release_iommu_mapping(struct drm_device *drm_dev)
 {
 	struct exynos_drm_private *priv = drm_dev->dev_private;
 
-	arm_iommu_release_mapping(priv->mapping);
+	__exynos_iommu_release_mapping(priv);
 }
 
 /*
@@ -77,25 +75,19 @@ int drm_iommu_attach_device(struct drm_device *drm_dev,
 	struct exynos_drm_private *priv = drm_dev->dev_private;
 	int ret;
 
-	if (!priv->mapping)
-		return 0;
-
-	subdrv_dev->dma_parms = devm_kzalloc(subdrv_dev,
-					sizeof(*subdrv_dev->dma_parms),
-					GFP_KERNEL);
-	if (!subdrv_dev->dma_parms)
-		return -ENOMEM;
-
-	dma_set_max_seg_size(subdrv_dev, 0xffffffffu);
-
-	if (subdrv_dev->archdata.mapping)
-		arm_iommu_detach_device(subdrv_dev);
+	if (get_dma_ops(priv->dma_dev) != get_dma_ops(subdrv_dev)) {
+		DRM_ERROR("Device %s lacks support for IOMMU\n",
+			  dev_name(subdrv_dev));
+		return -EINVAL;
+	}
 
-	ret = arm_iommu_attach_device(subdrv_dev, priv->mapping);
-	if (ret < 0) {
-		DRM_DEBUG_KMS("failed iommu attach.\n");
+	ret = configure_dma_max_seg_size(subdrv_dev);
+	if (ret)
 		return ret;
-	}
+
+	ret = __exynos_iommu_attach(priv, subdrv_dev);
+	if (ret)
+		clear_dma_max_seg_size(subdrv_dev);
 
 	return 0;
 }
@@ -113,10 +105,7 @@ void drm_iommu_detach_device(struct drm_device *drm_dev,
 				struct device *subdrv_dev)
 {
 	struct exynos_drm_private *priv = drm_dev->dev_private;
-	struct dma_iommu_mapping *mapping = priv->mapping;
-
-	if (!mapping || !mapping->domain)
-		return;
 
-	arm_iommu_detach_device(subdrv_dev);
+	__exynos_iommu_detach(priv, subdrv_dev);
+	clear_dma_max_seg_size(subdrv_dev);
 }

drivers/gpu/drm/exynos/exynos_drm_iommu.h

@@ -17,6 +17,97 @@
 
 #ifdef CONFIG_DRM_EXYNOS_IOMMU
 
+#if defined(CONFIG_ARM_DMA_USE_IOMMU)
+#include <asm/dma-iommu.h>
+
+static inline int __exynos_iommu_create_mapping(struct exynos_drm_private *priv,
+					unsigned long start, unsigned long size)
+{
+	priv->mapping = arm_iommu_create_mapping(&platform_bus_type, start,
+						 size);
+	return IS_ERR(priv->mapping);
+}
+
+static inline void
+__exynos_iommu_release_mapping(struct exynos_drm_private *priv)
+{
+	arm_iommu_release_mapping(priv->mapping);
+}
+
+static inline int __exynos_iommu_attach(struct exynos_drm_private *priv,
+					struct device *dev)
+{
+	if (dev->archdata.mapping)
+		arm_iommu_detach_device(dev);
+
+	return arm_iommu_attach_device(dev, priv->mapping);
+}
+
+static inline void __exynos_iommu_detach(struct exynos_drm_private *priv,
+					 struct device *dev)
+{
+	arm_iommu_detach_device(dev);
+}
+
+#elif defined(CONFIG_IOMMU_DMA)
+#include <linux/dma-iommu.h>
+
+static inline int __exynos_iommu_create_mapping(struct exynos_drm_private *priv,
+					unsigned long start, unsigned long size)
+{
+	struct iommu_domain *domain;
+	int ret;
+
+	domain = iommu_domain_alloc(priv->dma_dev->bus);
+	if (!domain)
+		return -ENOMEM;
+
+	ret = iommu_get_dma_cookie(domain);
+	if (ret)
+		goto free_domain;
+
+	ret = iommu_dma_init_domain(domain, start, size);
+	if (ret)
+		goto put_cookie;
+
+	priv->mapping = domain;
+	return 0;
+
+put_cookie:
+	iommu_put_dma_cookie(domain);
+free_domain:
+	iommu_domain_free(domain);
+	return ret;
+}
+
+static inline void __exynos_iommu_release_mapping(struct exynos_drm_private *priv)
+{
+	struct iommu_domain *domain = priv->mapping;
+
+	iommu_put_dma_cookie(domain);
+	iommu_domain_free(domain);
+	priv->mapping = NULL;
+}
+
+static inline int __exynos_iommu_attach(struct exynos_drm_private *priv,
+					struct device *dev)
+{
+	struct iommu_domain *domain = priv->mapping;
+
+	return iommu_attach_device(domain, dev);
+}
+
+static inline void __exynos_iommu_detach(struct exynos_drm_private *priv,
+					 struct device *dev)
+{
+	struct iommu_domain *domain = priv->mapping;
+
+	iommu_detach_device(domain, dev);
+}
+#else
+#error Unsupported architecture and IOMMU/DMA-mapping glue code
+#endif
+
 int drm_create_iommu_mapping(struct drm_device *drm_dev);
 
 void drm_release_iommu_mapping(struct drm_device *drm_dev);