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@samsung.com] Sent: Saturday, April 14, 2012 8:52 PM To: dri-devel@lists.freedesktop.org; linaro-mm-sig@lists.linaro.org Cc: inki.dae@samsung.com; subash.rp@samsung.com; prashanth.g@samsung.com; sunilm@samsung.com; prathyush.k@samsung.com 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@samsung.com
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