Changelog v3:
Passing the actual buffer size instead of vm_size to dma_mmap_attrs.
Changelog v2:
Extracting the private data from fb_info structure to obtain the exynos gem buffer structure. Now, dma address is obtained from the exynos gem buffer structure and not from smem_start. Also calling dma_mmap_attrs (instead of dma_mmap_writecombine) with the same attributes used during allocation.
Changelog v1:
This patch adds a exynos drm specific implementation of fb_mmap which supports mapping a non-contiguous buffer to user space.
This new function does not assume that the frame buffer is contiguous and calls dma_mmap_writecombine for mapping the buffer to user space. dma_mmap_writecombine will be able to map a contiguous buffer as well as non-contig buffer depending on whether an IOMMU mapping is created for drm or not.
Signed-off-by: Prathyush K prathyush.k@samsung.com --- drivers/gpu/drm/exynos/exynos_drm_fbdev.c | 30 +++++++++++++++++++++++++++++ 1 files changed, 30 insertions(+), 0 deletions(-)
diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c index 67eb6ba..a6f8cc2 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c +++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c @@ -46,8 +46,38 @@ struct exynos_drm_fbdev { struct exynos_drm_gem_obj *exynos_gem_obj; };
+static int exynos_drm_fb_mmap(struct fb_info *info, + struct vm_area_struct *vma) +{ + struct drm_fb_helper *helper = info->par; + struct exynos_drm_fbdev *exynos_fbd = to_exynos_fbdev(helper); + struct exynos_drm_gem_obj *exynos_gem_obj = exynos_fbd->exynos_gem_obj; + struct exynos_drm_gem_buf *buffer = exynos_gem_obj->buffer; + unsigned long vm_size; + int ret; + + DRM_DEBUG_KMS("%s\n", __func__); + + vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP; + + vm_size = vma->vm_end - vma->vm_start; + + if (vm_size > buffer->size) + return -EINVAL; + + ret = dma_mmap_attrs(helper->dev->dev, vma, buffer->kvaddr, + buffer->dma_addr, buffer->size, &buffer->dma_attrs); + if (ret < 0) { + DRM_ERROR("failed to mmap.\n"); + return ret; + } + + return 0; +} + static struct fb_ops exynos_drm_fb_ops = { .owner = THIS_MODULE, + .fb_mmap = exynos_drm_fb_mmap, .fb_fillrect = cfb_fillrect, .fb_copyarea = cfb_copyarea, .fb_imageblit = cfb_imageblit,