drm/exynos: use DMA_ATTR_NO_KERNEL_MAPPING attribute

Changelog v3:
just code cleanup.

Changelog v2:
fix argument to dma_mmap_attr function.
- use pages instead of kvaddr because kvaddr is 0 with
  DMA_ATTR_NO_KERNEL_MAPPING.

Changelog v1:
When gem allocation is requested, kernel space mapping isn't needed.
But if need, such as console framebuffer, the physical pages would be
mapped with kernel space though vmap function.

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

1 files changed, 17 insertions, 1 deletions

diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
index 885ef235d59..f433eb7533a 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
@@ -65,7 +65,7 @@ static int exynos_drm_fb_mmap(struct fb_info *info,
 	if (vm_size > buffer->size)
 		return -EINVAL;
 
-	ret = dma_mmap_attrs(helper->dev->dev, vma, buffer->kvaddr,
+	ret = dma_mmap_attrs(helper->dev->dev, vma, buffer->pages,
 		buffer->dma_addr, buffer->size, &buffer->dma_attrs);
 	if (ret < 0) {
 		DRM_ERROR("failed to mmap.\n");
@@ -109,6 +109,17 @@ static int exynos_drm_fbdev_update(struct drm_fb_helper *helper,
 		return -EFAULT;
 	}
 
+	/* 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,
+					pgprot_writecombine(PAGE_KERNEL));
+		if (!buffer->kvaddr) {
+			DRM_ERROR("failed to map pages to kernel space.\n");
+			return -EIO;
+		}
+	}
+
 	/* buffer count to framebuffer always is 1 at booting time. */
 	exynos_drm_fb_set_buf_cnt(fb, 1);
 
@@ -305,8 +316,13 @@ err_init:
 static void exynos_drm_fbdev_destroy(struct drm_device *dev,
 				      struct drm_fb_helper *fb_helper)
 {
+	struct exynos_drm_fbdev *exynos_fbd = to_exynos_fbdev(fb_helper);
+	struct exynos_drm_gem_obj *exynos_gem_obj = exynos_fbd->exynos_gem_obj;
 	struct drm_framebuffer *fb;
 
+	if (exynos_gem_obj->buffer->kvaddr)
+		vunmap(exynos_gem_obj->buffer->kvaddr);
+
 	/* release drm framebuffer and real buffer */
 	if (fb_helper->fb && fb_helper->fb->funcs) {
 		fb = fb_helper->fb;