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

2012/7/10, Cooper Yuan cooperyuan@gmail.com:

implement mmap function of dma_buf_ops.

please, add more comments and reveal the source of funding. I think the source of this patch is omap drm driver.

Signed-off-by: Cooper Yuan cooperyuan@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;

leave a space.

• 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));

exynos drm driver supports cache attributes, non-cachable or cachable so the cache attribute should also be considered. please set proper cache attribute checking current gem object.

• /* 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,

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