[PATCH v2] drm/exynos: consider no iommu support to console framebuffer

[Inki Dae]

This patch considers no iommu support to kernel space mapping
of console framebuffer.

Without iommu, we get physical address instead of device address
after dma_alloc_attrs function is called. So we should consider
the case without iommu when it maps console framebuffer with
kernel space.

Changelog v2:
- calll vunmap function only with iommu support.

Signed-off-by: Inki Dae <inki.dae at samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>
---
 drivers/gpu/drm/exynos/exynos_drm_fbdev.c |   22 ++++++++++++++++++----
 1 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
index f433eb7..eae064a 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
@@ -34,6 +34,7 @@
 #include "exynos_drm_drv.h"
 #include "exynos_drm_fb.h"
 #include "exynos_drm_gem.h"
+#include "exynos_drm_iommu.h"
 
 #define MAX_CONNECTOR		4
 #define PREFERRED_BPP		32
@@ -111,9 +112,18 @@ static int exynos_drm_fbdev_update(struct drm_fb_helper *helper,
 
 	/* map pages with kernel virtual space. */
 	if (!buffer->kvaddr) {
-		unsigned int nr_pages = buffer->size >> PAGE_SHIFT;
-		buffer->kvaddr = vmap(buffer->pages, nr_pages, VM_MAP,
+		if (is_drm_iommu_supported(dev)) {
+			unsigned int nr_pages = buffer->size >> PAGE_SHIFT;
+
+			buffer->kvaddr = vmap(buffer->pages, nr_pages, VM_MAP,
 					pgprot_writecombine(PAGE_KERNEL));
+		} else {
+			phys_addr_t dma_addr = buffer->dma_addr;
+			if (dma_addr)
+				buffer->kvaddr = phys_to_virt(dma_addr);
+			else
+				buffer->kvaddr = (void __iomem *)NULL;
+		}
 		if (!buffer->kvaddr) {
 			DRM_ERROR("failed to map pages to kernel space.\n");
 			return -EIO;
@@ -128,8 +138,12 @@ static int exynos_drm_fbdev_update(struct drm_fb_helper *helper,
 
 	dev->mode_config.fb_base = (resource_size_t)buffer->dma_addr;
 	fbi->screen_base = buffer->kvaddr + offset;
-	fbi->fix.smem_start = (unsigned long)
+	if (is_drm_iommu_supported(dev))
+		fbi->fix.smem_start = (unsigned long)
 			(page_to_phys(sg_page(buffer->sgt->sgl)) + offset);
+	else
+		fbi->fix.smem_start = (unsigned long)buffer->dma_addr;
+
 	fbi->screen_size = size;
 	fbi->fix.smem_len = size;
 
@@ -320,7 +334,7 @@ static void exynos_drm_fbdev_destroy(struct drm_device *dev,
 	struct exynos_drm_gem_obj *exynos_gem_obj = exynos_fbd->exynos_gem_obj;
 	struct drm_framebuffer *fb;
 
-	if (exynos_gem_obj->buffer->kvaddr)
+	if (is_drm_iommu_supported(dev) && exynos_gem_obj->buffer->kvaddr)
 		vunmap(exynos_gem_obj->buffer->kvaddr);
 
 	/* release drm framebuffer and real buffer */
-- 
1.7.4.1