Changelog v3: use drm_file's file object instead of gem object's - gem object's file represents the shmem storage so process-unique file object should be used instead.
Changelog v2: call mutex_lock before drm_vm_open_locked is called.
Changelog v1: This patch makes it takes a reference to gem object when specific gem mmap is requested. For this, it sets dev->driver->gem_vm_ops to vma->vm_ops.
And this patch is based on exynos-drm-next-iommu branch of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos
Signed-off-by: Inki Dae inki.dae@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com --- drivers/gpu/drm/exynos/exynos_drm_gem.c | 75 ++++++++++++++++++++++++++++-- 1 files changed, 70 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c index 50d73f1..fdabb0f 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_gem.c +++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c @@ -365,17 +365,53 @@ int exynos_drm_gem_map_offset_ioctl(struct drm_device *dev, void *data, &args->offset); }
+static struct drm_file *exynos_drm_find_drm_file(struct drm_device *drm_dev, + struct file *filp) +{ + struct drm_file *file_priv; + + mutex_lock(&drm_dev->struct_mutex); + + /* find current process's drm_file from filelist. */ + list_for_each_entry(file_priv, &drm_dev->filelist, lhead) { + if (file_priv->filp == filp) { + mutex_unlock(&drm_dev->struct_mutex); + return file_priv; + } + } + + mutex_unlock(&drm_dev->struct_mutex); + WARN_ON(1); + + return ERR_PTR(-EFAULT); +} + static int exynos_drm_gem_mmap_buffer(struct file *filp, struct vm_area_struct *vma) { struct drm_gem_object *obj = filp->private_data; struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj); + struct drm_device *drm_dev = obj->dev; struct exynos_drm_gem_buf *buffer; + struct drm_file *file_priv; unsigned long vm_size; + int ret;
DRM_DEBUG_KMS("%s\n", __FILE__);
vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP; + vma->vm_private_data = obj; + vma->vm_ops = drm_dev->driver->gem_vm_ops; + + /* restore it to driver's fops. */ + filp->f_op = fops_get(drm_dev->driver->fops); + + file_priv = exynos_drm_find_drm_file(drm_dev, filp); + if (IS_ERR(file_priv)) + return PTR_ERR(file_priv); + + /* restore it to drm_file. */ + filp->private_data = file_priv;
update_vm_cache_attr(exynos_gem_obj, vma);
@@ -391,9 +427,25 @@ static int exynos_drm_gem_mmap_buffer(struct file *filp, if (vm_size > buffer->size) return -EINVAL;
- return dma_mmap_attrs(obj->dev->dev, vma, buffer->kvaddr, + ret = dma_mmap_attrs(drm_dev->dev, vma, buffer->kvaddr, buffer->dma_addr, buffer->size, &buffer->dma_attrs); + if (ret < 0) { + DRM_ERROR("failed to mmap.\n"); + return ret; + } + + /* + * take a reference to this mapping of the object. And this reference + * is unreferenced by the corresponding vm_close call. + */ + drm_gem_object_reference(obj); + + mutex_lock(&drm_dev->struct_mutex); + drm_vm_open_locked(drm_dev, vma); + mutex_unlock(&drm_dev->struct_mutex); + + return 0; }
static const struct file_operations exynos_drm_gem_fops = { @@ -420,16 +472,29 @@ int exynos_drm_gem_mmap_ioctl(struct drm_device *dev, void *data, return -EINVAL; }
- obj->filp->f_op = &exynos_drm_gem_fops; - obj->filp->private_data = obj; + /* + * Set specific mmper's fops. And it will be restored by + * exynos_drm_gem_mmap_buffer to dev->driver->fops. + * This is used to call specific mapper temporarily. + */ + file_priv->filp->f_op = &exynos_drm_gem_fops;
- addr = vm_mmap(obj->filp, 0, args->size, + /* + * Set gem object to private_data so that specific mmaper + * can get the gem object. And it will be restored by + * exynos_drm_gem_mmap_buffer to drm_file. + */ + file_priv->filp->private_data = obj; + + addr = vm_mmap(file_priv->filp, 0, args->size, PROT_READ | PROT_WRITE, MAP_SHARED, 0);
drm_gem_object_unreference_unlocked(obj);
- if (IS_ERR((void *)addr)) + if (IS_ERR((void *)addr)) { + file_priv->filp->private_data = file_priv; return PTR_ERR((void *)addr); + }
args->mapped = addr;