Hi, This is also patch set based on old version and the feature below has already been merged to mainline. Prathyush, please DO WORK patch set based on latest drm-next for new feature and drm-fixes for bug fixes from next time and also include me as Maintainer. Thanks, Inki Dae. > -----Original Message----- > From: Prathyush [mailto:prathyush.k@xxxxxxxxxxx] > Sent: Saturday, April 14, 2012 8:52 PM > To: dri-devel@xxxxxxxxxxxxxxxxxxxxx; linaro-mm-sig@xxxxxxxxxxxxxxxx > Cc: inki.dae@xxxxxxxxxxx; subash.rp@xxxxxxxxxxx; prashanth.g@xxxxxxxxxxx; > sunilm@xxxxxxxxxxx; prathyush.k@xxxxxxxxxxx > Subject: [PATCH 2/4] [RFC] drm/exynos: Mapping of gem objects uses > dma_mmap_writecombine > > GEM objects get mapped to user space in two ways - DIRECT and > INDIRECT mapping. DIRECT mapping is by calling an ioctl and it > maps all the pages to user space by calling remap-pfn-range. > Indirect mapping is done by calling 'mmap'. The actual mapping > is done when a page fault gets generated and is handled by > exynos_drm_gem_fault function where the required page is mapped. > Both the methods assume contiguous memory. > > With this change, the mapping is done by dma_mmap_writecombine > which will support mapping of non-contiguous memory to user space. > > This works similar to the previous approach for the case of > DIRECT mapping. But in the case of mapping when a page fault > occurs, dma_mmap_writecombine will map all the pages and not just > one page. > > Signed-off-by: Prathyush K <prathyush.k@xxxxxxxxxxx> > --- > drivers/gpu/drm/exynos/exynos_drm_gem.c | 70 ++++++++++++++------------- > --- > 1 files changed, 33 insertions(+), 37 deletions(-) > > diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c > b/drivers/gpu/drm/exynos/exynos_drm_gem.c > index 807143e..a57a83a 100755 > --- a/drivers/gpu/drm/exynos/exynos_drm_gem.c > +++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c > @@ -200,40 +200,27 @@ static int exynos_drm_gem_mmap_buffer(struct file > *filp, > { > struct drm_gem_object *obj = filp->private_data; > struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj); > - struct exynos_drm_gem_buf *buffer; > - unsigned long pfn, vm_size; > - > - DRM_DEBUG_KMS("%s\n", __FILE__); > + void *kva; > + dma_addr_t dma_address; > + unsigned long ret; > > - vma->vm_flags |= (VM_IO | VM_RESERVED); > + kva = exynos_gem_obj->buffer->kvaddr; > > - /* in case of direct mapping, always having non-cachable attribute > */ > - vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); > - vma->vm_file = filp; > - > - vm_size = vma->vm_end - vma->vm_start; > - /* > - * a buffer contains information to physically continuous memory > - * allocated by user request or at framebuffer creation. > - */ > - buffer = exynos_gem_obj->buffer; > - > - /* check if user-requested size is valid. */ > - if (vm_size > buffer->size) > - return -EINVAL; > + if (kva == NULL) { > + DRM_ERROR("No KVA Found\n"); > + return -EAGAIN; > + } > > - /* > - * get page frame number to physical memory to be mapped > - * to user space. > - */ > - pfn = ((unsigned long)exynos_gem_obj->buffer->dma_addr) >> > PAGE_SHIFT; > + dma_address = exynos_gem_obj->buffer->dma_addr; > + vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED; > + vma->vm_pgoff = 0; > > - DRM_DEBUG_KMS("pfn = 0x%lx\n", pfn); > + ret = dma_mmap_writecombine(obj->dev->dev, vma, kva, > + dma_address, vma->vm_end - vma->vm_start); > > - if (remap_pfn_range(vma, vma->vm_start, pfn, vm_size, > - vma->vm_page_prot)) { > - DRM_ERROR("failed to remap pfn range.\n"); > - return -EAGAIN; > + if (ret) { > + DRM_ERROR("Remapping memory failed, error: %ld\n", ret); > + return ret; > } > > return 0; > @@ -433,19 +420,29 @@ int exynos_drm_gem_fault(struct vm_area_struct *vma, > struct vm_fault *vmf) > struct drm_gem_object *obj = vma->vm_private_data; > struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj); > struct drm_device *dev = obj->dev; > - unsigned long pfn; > - pgoff_t page_offset; > + void *kva; > + dma_addr_t dma_address; > int ret; > > - page_offset = ((unsigned long)vmf->virtual_address - > - vma->vm_start) >> PAGE_SHIFT; > + kva = exynos_gem_obj->buffer->kvaddr; > + > + if (kva == NULL) { > + DRM_ERROR("No KVA Found\n"); > + return -EAGAIN; > + } > > mutex_lock(&dev->struct_mutex); > > - pfn = (((unsigned long)exynos_gem_obj->buffer->dma_addr) >> > - PAGE_SHIFT) + page_offset; > > - ret = vm_insert_mixed(vma, (unsigned long)vmf->virtual_address, > pfn); > + dma_address = exynos_gem_obj->buffer->dma_addr; > + vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED; > + vma->vm_pgoff = 0; > + > + ret = dma_mmap_writecombine(obj->dev->dev, vma, kva, > + dma_address, vma->vm_end - vma->vm_start); > + > + if (ret) > + DRM_ERROR("Remapping memory failed, error: %d\n", ret); > > mutex_unlock(&dev->struct_mutex); > > @@ -457,7 +454,6 @@ int exynos_drm_gem_mmap(struct file *filp, struct > vm_area_struct *vma) > int ret; > > DRM_DEBUG_KMS("%s\n", __FILE__); > - > /* set vm_area_struct. */ > ret = drm_gem_mmap(filp, vma); > if (ret < 0) { > -- > 1.7.0.4 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
