[PATCH 1/7] drm/exynos: create common IOMMU mapping for DRM

[Prathyush K]

This patch creates an IOMMU mapping during drm init. This is used by
all the drm devices including the exynos drm virtual device. This
ensures that when drm creates a buffer using the dma-mapping framework,
this buffer is accessible by all the drm devices like hdmi/fimd.

Signed-off-by: Prathyush K <prathyush.k at samsung.com>
---
 drivers/gpu/drm/exynos/exynos_drm_core.c |    3 +++
 drivers/gpu/drm/exynos/exynos_drm_drv.c  |   21 +++++++++++++++++++++
 drivers/gpu/drm/exynos/exynos_drm_drv.h  |   10 ++++++++++
 3 files changed, 34 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_core.c b/drivers/gpu/drm/exynos/exynos_drm_core.c
index eaf630d..13ecca6 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_core.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_core.c
@@ -34,6 +34,9 @@
 
 static LIST_HEAD(exynos_drm_subdrv_list);
 static struct drm_device *drm_dev;
+#ifdef CONFIG_EXYNOS_IOMMU
+struct dma_iommu_mapping *exynos_drm_common_mapping;
+#endif
 
 static int exynos_drm_subdrv_probe(struct drm_device *dev,
 					struct exynos_drm_subdrv *subdrv)
diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.c b/drivers/gpu/drm/exynos/exynos_drm_drv.c
index d6de2e0..c3ad87e 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_drv.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_drv.c
@@ -307,6 +307,18 @@ static int __init exynos_drm_init(void)
 
 	DRM_DEBUG_DRIVER("%s\n", __FILE__);
 
+#ifdef CONFIG_EXYNOS_IOMMU
+	exynos_drm_common_mapping = arm_iommu_create_mapping(&platform_bus_type,
+					EXYNOS_DRM_DMA_ADDR,
+					EXYNOS_DRM_IOMMU_SIZE,
+					EXYNOS_DRM_IOMMU_ORDER);
+	if (IS_ERR_OR_NULL(exynos_drm_common_mapping)) {
+		DRM_ERROR("failed to created IOMMU mapping\n");
+		ret = PTR_ERR(exynos_drm_common_mapping);
+		goto out_iommu;
+	}
+#endif
+
 #ifdef CONFIG_DRM_EXYNOS_FIMD
 	ret = platform_driver_register(&fimd_driver);
 	if (ret < 0)
@@ -367,6 +379,11 @@ out_hdmi:
 	platform_driver_unregister(&fimd_driver);
 out_fimd:
 #endif
+#ifdef CONFIG_EXYNOS_IOMMU
+	arm_iommu_release_mapping(exynos_drm_common_mapping);
+	exynos_drm_common_mapping = NULL;
+out_iommu:
+#endif
 	return ret;
 }
 
@@ -393,6 +410,10 @@ static void __exit exynos_drm_exit(void)
 #ifdef CONFIG_DRM_EXYNOS_FIMD
 	platform_driver_unregister(&fimd_driver);
 #endif
+#ifdef CONFIG_EXYNOS_IOMMU
+	arm_iommu_release_mapping(exynos_drm_common_mapping);
+	exynos_drm_common_mapping = NULL;
+#endif
 }
 
 module_init(exynos_drm_init);
diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.h b/drivers/gpu/drm/exynos/exynos_drm_drv.h
index c82c90c..bd12ee2 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_drv.h
+++ b/drivers/gpu/drm/exynos/exynos_drm_drv.h
@@ -31,11 +31,18 @@
 
 #include <linux/module.h>
 #include "drm.h"
+#ifdef CONFIG_EXYNOS_IOMMU
+#include <asm/dma-iommu.h>
+#include <mach/sysmmu.h>
+#endif
 
 #define MAX_CRTC	3
 #define MAX_PLANE	5
 #define MAX_FB_BUFFER	4
 #define DEFAULT_ZPOS	-1
+#define EXYNOS_DRM_DMA_ADDR	0x20000000
+#define EXYNOS_DRM_IOMMU_SIZE	SZ_128M
+#define EXYNOS_DRM_IOMMU_ORDER	4
 
 struct drm_device;
 struct exynos_drm_overlay;
@@ -304,4 +311,7 @@ extern struct platform_driver mixer_driver;
 extern struct platform_driver exynos_drm_common_hdmi_driver;
 extern struct platform_driver vidi_driver;
 extern struct platform_driver g2d_driver;
+#ifdef CONFIG_EXYNOS_IOMMU
+extern struct dma_iommu_mapping *exynos_drm_common_mapping;
+#endif
 #endif
-- 
1.7.0.4