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 <prathyus...@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
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