[PATCH 2/3] drm/exynos: add dmabuf mmap function

[Cooper Yuan]

implement mmap function of dma_buf_ops.

Signed-off-by: Cooper Yuan <cooperyuan at gmail.com>
---
 drivers/gpu/drm/exynos/exynos_drm_dmabuf.c |   38 ++++++++++++++++++++++++++++
 1 files changed, 38 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
b/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
index e4eeb0b..913a23e 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
@@ -164,6 +164,43 @@ static void exynos_gem_dmabuf_kunmap(struct
dma_buf *dma_buf,
        /* TODO */
 }

+static int exynos_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct
vm_area_struct *vma)
+{
+       struct exynos_drm_gem_obj *exynos_gem_obj = dma_buf->priv;
+       struct drm_device *dev = exynos_gem_obj->base.dev;
+       struct exynos_drm_gem_buf *buf = exynos_gem_obj->buffer;
+       int ret = 0;
+       if (WARN_ON(!exynos_gem_obj->base.filp))
+               return -EINVAL;
+
+       /* Check for valid size. */
+       if (buf->size < vma->vm_end - vma->vm_start) {
+               ret = -EINVAL;
+               goto out_unlock;
+       }
+
+       if (!dev->driver->gem_vm_ops) {
+               ret = -EINVAL;
+               goto out_unlock;
+       }
+
+       vma->vm_flags |= VM_RESERVED | VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
+       vma->vm_ops = dev->driver->gem_vm_ops;
+       vma->vm_private_data = exynos_gem_obj;
+       vma->vm_page_prot =  
pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
+
+       /* Take a ref for this mapping of the object, so that the fault
+        * handler can dereference the mmap offset's pointer to the object.
+        * This reference is cleaned up by the corresponding vm_close
+        * (which should happen whether the vma was created by this call, or
+        * by a vm_open due to mremap or partial unmap or whatever).
+        */
+       vma->vm_ops->open(vma);
+
+out_unlock:
+       return ret;
+}
+
 static struct dma_buf_ops exynos_dmabuf_ops = {
        .map_dma_buf            = exynos_gem_map_dma_buf,
        .unmap_dma_buf          = exynos_gem_unmap_dma_buf,
@@ -172,6 +209,7 @@ static struct dma_buf_ops exynos_dmabuf_ops = {
        .kunmap                 = exynos_gem_dmabuf_kunmap,
        .kunmap_atomic          = exynos_gem_dmabuf_kunmap_atomic,
        .release                = exynos_dmabuf_release,
+       .mmap                   = exynos_gem_dmabuf_mmap,
 };

 struct dma_buf *exynos_dmabuf_prime_export(struct drm_device *drm_dev,
-- 
1.7.0.4