drm/exynos: add iommu support for exynos drm framework

Changelog v4:
- fix condition to drm_iommu_detach_device funtion.

Changelog v3:
- add dma_parms->max_segment_size setting of drm_device->dev.
- use devm_kzalloc instead of kzalloc.

Changelog v2:
- fix iommu attach condition.
  . check archdata.dma_ops of drm device instead of
    subdrv device's one.
- code clean to exynos_drm_iommu.c file.
  . remove '#ifdef CONFIG_ARM_DMA_USE_IOMMU' from exynos_drm_iommu.c
    and add it to driver/gpu/drm/exynos/Kconfig.

Changelog v1:
This patch adds iommu support for exynos drm framework with dma mapping
api. In this patch, we used dma mapping api to allocate physical memory
and maps it with iommu table and removed some existing codes and added
new some codes for iommu support.

GEM allocation requires one device object to use dma mapping api so
this patch uses one iommu mapping for all sub drivers. In other words,
all sub drivers have same iommu mapping.

Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>

1 files changed, 51 insertions, 1 deletions

diff --git a/drivers/gpu/drm/exynos/exynos_drm_fb.c b/drivers/gpu/drm/exynos/exynos_drm_fb.c
index 4ef4cd3f993..7190b64a368 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_fb.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_fb.c
@@ -30,10 +30,12 @@
 #include <drm/drm_crtc.h>
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_fb_helper.h>
+#include <uapi/drm/exynos_drm.h>
 
 #include "exynos_drm_drv.h"
 #include "exynos_drm_fb.h"
 #include "exynos_drm_gem.h"
+#include "exynos_drm_iommu.h"
 
 #define to_exynos_fb(x)	container_of(x, struct exynos_drm_fb, fb)
 
@@ -50,6 +52,32 @@ struct exynos_drm_fb {
 	struct exynos_drm_gem_obj	*exynos_gem_obj[MAX_FB_BUFFER];
 };
 
+static int check_fb_gem_memory_type(struct drm_device *drm_dev,
+				struct exynos_drm_gem_obj *exynos_gem_obj)
+{
+	unsigned int flags;
+
+	/*
+	 * if exynos drm driver supports iommu then framebuffer can use
+	 * all the buffer types.
+	 */
+	if (is_drm_iommu_supported(drm_dev))
+		return 0;
+
+	flags = exynos_gem_obj->flags;
+
+	/*
+	 * without iommu support, not support physically non-continuous memory
+	 * for framebuffer.
+	 */
+	if (IS_NONCONTIG_BUFFER(flags)) {
+		DRM_ERROR("cannot use this gem memory type for fb.\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static void exynos_drm_fb_destroy(struct drm_framebuffer *fb)
 {
 	struct exynos_drm_fb *exynos_fb = to_exynos_fb(fb);
@@ -128,14 +156,25 @@ exynos_drm_framebuffer_init(struct drm_device *dev,
 			    struct drm_gem_object *obj)
 {
 	struct exynos_drm_fb *exynos_fb;
+	struct exynos_drm_gem_obj *exynos_gem_obj;
 	int ret;
 
+	exynos_gem_obj = to_exynos_gem_obj(obj);
+
+	ret = check_fb_gem_memory_type(dev, exynos_gem_obj);
+	if (ret < 0) {
+		DRM_ERROR("cannot use this gem memory type for fb.\n");
+		return ERR_PTR(-EINVAL);
+	}
+
 	exynos_fb = kzalloc(sizeof(*exynos_fb), GFP_KERNEL);
 	if (!exynos_fb) {
 		DRM_ERROR("failed to allocate exynos drm framebuffer\n");
 		return ERR_PTR(-ENOMEM);
 	}
 
+	exynos_fb->exynos_gem_obj[0] = exynos_gem_obj;
+
 	ret = drm_framebuffer_init(dev, &exynos_fb->fb, &exynos_drm_fb_funcs);
 	if (ret) {
 		DRM_ERROR("failed to initialize framebuffer\n");
@@ -143,7 +182,6 @@ exynos_drm_framebuffer_init(struct drm_device *dev,
 	}
 
 	drm_helper_mode_fill_fb_struct(&exynos_fb->fb, mode_cmd);
-	exynos_fb->exynos_gem_obj[0] = to_exynos_gem_obj(obj);
 
 	return &exynos_fb->fb;
 }
@@ -214,6 +252,9 @@ exynos_user_fb_create(struct drm_device *dev, struct drm_file *file_priv,
 	DRM_DEBUG_KMS("buf_cnt = %d\n", exynos_fb->buf_cnt);
 
 	for (i = 1; i < exynos_fb->buf_cnt; i++) {
+		struct exynos_drm_gem_obj *exynos_gem_obj;
+		int ret;
+
 		obj = drm_gem_object_lookup(dev, file_priv,
 				mode_cmd->handles[i]);
 		if (!obj) {
@@ -222,6 +263,15 @@ exynos_user_fb_create(struct drm_device *dev, struct drm_file *file_priv,
 			return ERR_PTR(-ENOENT);
 		}
 
+		exynos_gem_obj = to_exynos_gem_obj(obj);
+
+		ret = check_fb_gem_memory_type(dev, exynos_gem_obj);
+		if (ret < 0) {
+			DRM_ERROR("cannot use this gem memory type for fb.\n");
+			exynos_drm_fb_destroy(fb);
+			return ERR_PTR(ret);
+		}
+
 		exynos_fb->exynos_gem_obj[i] = to_exynos_gem_obj(obj);
 	}