Re: [PATCH] drm/rockchip: use drm_gem_mmap helpers

[Mark yao <mark.yao@rock-chips.com>]

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On 2015年07月07日 20:04, Daniel Vetter wrote:
> On Tue, Jul 07, 2015 at 05:03:36PM +0800, Daniel Kurtz wrote:
>> Rather than (incompletely [0]) re-implementing drm_gem_mmap() and
>> drm_gem_mmap_obj() helpers, call them directly from the rockchip mmap
>> routines.
>>
>> Once the core functions return successfully, the rockchip mmap routines
>> can still use dma_mmap_attrs() to simply mmap the entire buffer.
>>
>> [0] Previously, we were performing the mmap() without first taking a
>> reference on the underlying gem buffer.  This could leak ptes if the gem
>> object is destroyed while userspace is still holding the mapping.
>>
>> Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
>> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
>> Cc: stable@vger.kernel.org
> Applied to topic/drm-fixes to make sure it won't get lost, but I expect
> rockchip maintainers to pick this one up.
> -Daniel
I try to pick this patch up, but found it conflicts with patch [0].  Can 
you fix it?

[0]https://patchwork.kernel.org/patch/6226591/

-Mark
>> ---
>>   drivers/gpu/drm/rockchip/rockchip_drm_gem.c | 67 +++++++++++++++--------------
>>   1 file changed, 34 insertions(+), 33 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
>> index eb2282c..eba5f8a 100644
>> --- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
>> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
>> @@ -54,55 +54,56 @@ static void rockchip_gem_free_buf(struct rockchip_gem_object *rk_obj)
>>   		       &rk_obj->dma_attrs);
>>   }
>>   
>> -int rockchip_gem_mmap_buf(struct drm_gem_object *obj,
>> -			  struct vm_area_struct *vma)
>> +static int rockchip_drm_gem_object_mmap(struct drm_gem_object *obj,
>> +					struct vm_area_struct *vma)
>> +
>>   {
>> +	int ret;
>>   	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
>>   	struct drm_device *drm = obj->dev;
>> -	unsigned long vm_size;
>>   
>> -	vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
>> -	vm_size = vma->vm_end - vma->vm_start;
>> -
>> -	if (vm_size > obj->size)
>> -		return -EINVAL;
>> +	/*
>> +	 * dma_alloc_attrs() allocated a struct page table for rk_obj, so clear
>> +	 * VM_PFNMAP flag that was set by drm_gem_mmap_obj()/drm_gem_mmap().
>> +	 */
>> +	vma->vm_flags &= ~VM_PFNMAP;
>>   
>> -	return dma_mmap_attrs(drm->dev, vma, rk_obj->kvaddr, rk_obj->dma_addr,
>> +	ret = dma_mmap_attrs(drm->dev, vma, rk_obj->kvaddr, rk_obj->dma_addr,
>>   			     obj->size, &rk_obj->dma_attrs);
>> +	if (ret)
>> +		drm_gem_vm_close(vma);
>> +
>> +	return ret;
>>   }
>>   
>> -/* drm driver mmap file operations */
>> -int rockchip_gem_mmap(struct file *filp, struct vm_area_struct *vma)
>> +int rockchip_gem_mmap_buf(struct drm_gem_object *obj,
>> +			  struct vm_area_struct *vma)
>>   {
>> -	struct drm_file *priv = filp->private_data;
>> -	struct drm_device *dev = priv->minor->dev;
>> -	struct drm_gem_object *obj;
>> -	struct drm_vma_offset_node *node;
>> +	struct drm_device *drm = obj->dev;
>>   	int ret;
>>   
>> -	if (drm_device_is_unplugged(dev))
>> -		return -ENODEV;
>> +	mutex_lock(&drm->struct_mutex);
>> +	ret = drm_gem_mmap_obj(obj, obj->size, vma);
>> +	mutex_unlock(&drm->struct_mutex);
>> +	if (ret)
>> +		return ret;
>>   
>> -	mutex_lock(&dev->struct_mutex);
>> +	return rockchip_drm_gem_object_mmap(obj, vma);
>> +}
>>   
>> -	node = drm_vma_offset_exact_lookup(dev->vma_offset_manager,
>> -					   vma->vm_pgoff,
>> -					   vma_pages(vma));
>> -	if (!node) {
>> -		mutex_unlock(&dev->struct_mutex);
>> -		DRM_ERROR("failed to find vma node.\n");
>> -		return -EINVAL;
>> -	} else if (!drm_vma_node_is_allowed(node, filp)) {
>> -		mutex_unlock(&dev->struct_mutex);
>> -		return -EACCES;
>> -	}
>> +/* drm driver mmap file operations */
>> +int rockchip_gem_mmap(struct file *filp, struct vm_area_struct *vma)
>> +{
>> +	struct drm_gem_object *obj;
>> +	int ret;
>>   
>> -	obj = container_of(node, struct drm_gem_object, vma_node);
>> -	ret = rockchip_gem_mmap_buf(obj, vma);
>> +	ret = drm_gem_mmap(filp, vma);
>> +	if (ret)
>> +		return ret;
>>   
>> -	mutex_unlock(&dev->struct_mutex);
>> +	obj = vma->vm_private_data;
>>   
>> -	return ret;
>> +	return rockchip_drm_gem_object_mmap(obj, vma);
>>   }
>>   
>>   struct rockchip_gem_object *
>> -- 
>> 2.4.3.573.g4eafbef
>>


-- 
Ｍark


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