[PATCH v3 5/7] drm/vmwgfx: Inline ttm_bo_mmap() into vmwgfx driver

[Thomas Zimmermann]

Hi

Am 16.04.21 um 15:51 schrieb Christian König:
> Am 16.04.21 um 15:46 schrieb Christian König:
>> Am 16.04.21 um 15:31 schrieb Thomas Zimmermann:
>>> The vmwgfx driver is the only remaining user of ttm_bo_mmap(). Inline
>>> the code. The internal helper ttm_bo_vm_lookup() is now also part of
>>> vmwgfx as vmw_bo_vm_lookup().
>>>
>>> v2:
>>>     * replace pr_err() with drm_err() (Zack)
>>>
>>> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
>>> Reviewed-by: Zack Rusin <zackr at vmware.com>
>>> ---
>>>   drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c | 56 ++++++++++++++++++++++--
>>>   1 file changed, 53 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c 
>>> b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c
>>> index cb9975889e2f..c8b6543b4e39 100644
>>> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c
>>> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c
>>> @@ -27,6 +27,32 @@
>>>     #include "vmwgfx_drv.h"
>>>   +static struct ttm_buffer_object *vmw_bo_vm_lookup(struct 
>>> ttm_device *bdev,
>>> +                          unsigned long offset,
>>> +                          unsigned long pages)
>>> +{
>>> +    struct vmw_private *dev_priv = container_of(bdev, struct 
>>> vmw_private, bdev);
>>> +    struct drm_device *drm = &dev_priv->drm;
>>> +    struct drm_vma_offset_node *node;
>>> +    struct ttm_buffer_object *bo = NULL;
>>> +
>>> +    drm_vma_offset_lock_lookup(bdev->vma_manager);
>>> +
>>> +    node = drm_vma_offset_lookup_locked(bdev->vma_manager, offset, 
>>> pages);
>>> +    if (likely(node)) {
>>> +        bo = container_of(node, 
struct ttm_buffer_object,
>>> +                  base.vma_node);
>>> +        bo = ttm_bo_get_unless_zero(bo);
>>> +    }
>>> +
>>> +    drm_vma_offset_unlock_lookup(bdev->vma_manager);
>>> +
>>> +    if (!bo)
>>> +        drm_err(drm, "Could not find buffer object to map\n");
>>> +
>>> +    return bo;
>>> +}
>>> +
>>>   int vmw_mmap(struct file *filp, struct vm_area_struct *vma)
>>>   {
>>>       static const struct vm_operations_struct vmw_vm_ops = {
>>> @@ -41,10 +67,28 @@ int vmw_mmap(struct file *filp, struct 
>>> vm_area_struct *vma)
>>>       };
>>>       struct drm_file *file_priv = filp->private_data;
>>>       struct vmw_private *dev_priv = vmw_priv(file_priv->minor->dev);
>>> -    int ret = ttm_bo_mmap(filp, vma, &dev_priv->bdev);
>>> +    struct ttm_device *bdev = &dev_priv->bdev;
>>> +    struct ttm_buffer_object *bo;
>>> +    int ret;
>>> +
>>> +    if (unlikely(vma->vm_pgoff < DRM_FILE_PAGE_OFFSET_START))
>>> +        return -EINVAL;
>>> +
>>> +    bo = vmw_bo_vm_lookup(bdev, vma->vm_pgoff, vma_pages(vma));
>>> +    if (unlikely(!bo))
>>> +        return -EINVAL;
>>>   -    if (ret)
>>> -        return ret;
>>> +    if (unlikely(!bo->bdev->funcs->verify_access)) {
>>> +        ret = -EPERM;
>>> +        goto out_unref;
>>> +    }
>>> +    ret = bo->bdev->funcs->verify_access(bo, filp);
>>
>> Is there any reason we can't call vmw_verify_access() directly here?
>>
>> Would allow us to completely nuke the verify_access callback as well 
>> as far as I can see.
> 
> Forget what I said, couldn't see the next patch in my mailbox at time of 
> writing.
> 
> Whole series is Reviewed-by: Christian König <christian.koenig at amd.com>

Thanks a lot. If I'm not mistaken, the patches at [1] need to go in 
first. So it could take a a bit until this lands.

Otherwise, this series could go through the same tree as [1] if nouveau 
and vmwgfx devs don't mind.

Best regards
Thomas

[1] https://patchwork.freedesktop.org/series/88822/

> 
> Thanks for the nice cleanup,
> Christian.
> 
>>
>> Regards,
>> Christian.
>>
>>> +    if (unlikely(ret != 0))
>>> +        goto out_unref;
>>> +
>>> +    ret = ttm_bo_mmap_obj(vma, bo);
>>> +    if (unlikely(ret != 0))
>>> +        goto out_unref;
>>>         vma->vm_ops = &vmw_vm_ops;
>>>   @@ -52,7 +96,13 @@ int vmw_mmap(struct file *filp, struct 
>>> vm_area_struct *vma)
>>>       if (!is_cow_mapping(vma->vm_flags))
>>>           vma->vm_flags = (vma->vm_flags & ~VM_MIXEDMAP) | VM_PFNMAP;
>>>   +    ttm_bo_put(bo); /* release extra ref taken 
by 
>>> ttm_bo_mmap_obj() */
>>> +
>>>       return 0;
>>> +
>>> +out_unref:
>>> +    ttm_bo_put(bo);
>>> +    return ret;
>>>   }
>>>     /* struct vmw_validation_mem callback */
>>
> 
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> dri-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer

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