Re: [RESEND PATCH V1] accel/amdxdna: Call dma_buf_vmap_unlocked() for imported object

[Lizhi Hou]

On 9/16/25 08:55, Falkowski, Maciej wrote:
> On 9/15/2025 6:10 PM, Lizhi Hou wrote:
>
> > In amdxdna_gem_obj_vmap(), calling dma_buf_vmap() triggers a kernel
> > warning if LOCKDEP is enabled. So for imported object, use
> > dma_buf_vmap_unlocked(). Then, use drm_gem_vmap() for other objects.
> > The similar change applies to vunmap code.
> >
> > Fixes: bd72d4acda10 ("accel/amdxdna: Support user space allocated 
> > buffer")
> > Signed-off-by: Lizhi Hou <lizhi.hou@xxxxxxx>
> > ---
> >   drivers/accel/amdxdna/amdxdna_gem.c | 38 +++++++++++------------------
> >   1 file changed, 14 insertions(+), 24 deletions(-)
> >
> > diff --git a/drivers/accel/amdxdna/amdxdna_gem.c 
> > b/drivers/accel/amdxdna/amdxdna_gem.c
> > index d407a36eb412..50950be189ae 100644
> > --- a/drivers/accel/amdxdna/amdxdna_gem.c
> > +++ b/drivers/accel/amdxdna/amdxdna_gem.c
> > @@ -392,35 +392,25 @@ static const struct dma_buf_ops 
> > amdxdna_dmabuf_ops = {
> >       .vunmap = drm_gem_dmabuf_vunmap,
> >   };
> >   -static int amdxdna_gem_obj_vmap(struct drm_gem_object *obj, struct 
> > iosys_map *map)
> > +static int amdxdna_gem_obj_vmap(struct amdxdna_gem_obj *abo, struct 
> > iosys_map *map)
> >   {
> > -    struct amdxdna_gem_obj *abo = to_xdna_obj(obj);
> > -
> >       iosys_map_clear(map);
> >   -    dma_resv_assert_held(obj->resv);
> > -
> >       if (is_import_bo(abo))
> > -        dma_buf_vmap(abo->dma_buf, map);
> > -    else
> > -        drm_gem_shmem_object_vmap(obj, map);
> > -
> > -    if (!map->vaddr)
> > -        return -ENOMEM;
> > +        return dma_buf_vmap_unlocked(abo->dma_buf, map);
> Hi,
>
> The dma_buf_vmap_unlocked() will call iosys_map_clear at its start so 
> that
> in this case it will be called twice. Probably it will be optimize 
> out, but maybe
> its something to better omit.
Ok. I will remove iosys_map_clear. The caller uses cleared map even 
drm_gem_vmap might not clear it.
> >   -    return 0;
> > +    return drm_gem_vmap(to_gobj(abo), map);
> >   }
> >   -static void amdxdna_gem_obj_vunmap(struct drm_gem_object *obj, 
> > struct iosys_map *map)
> > +static void amdxdna_gem_obj_vunmap(struct amdxdna_gem_obj *abo, 
> > struct iosys_map *map)
> >   {
> > -    struct amdxdna_gem_obj *abo = to_xdna_obj(obj);
> > -
> > -    dma_resv_assert_held(obj->resv);
> > +    if (iosys_map_is_null(map))
> > +        return;
> >         if (is_import_bo(abo))
> > -        dma_buf_vunmap(abo->dma_buf, map);
> > -    else
> > -        drm_gem_shmem_object_vunmap(obj, map);
> > +        return dma_buf_vunmap_unlocked(abo->dma_buf, map);
> I do also wonder what is the convention here on clearing iosys_map 
> when returning.
> The function drm_gem_vunmap will clear the map for callers while the 
> other not.
> I think at least comment explaining the logic will be necessary.

The input map will not be re-used, so it does not mater if it is cleared 
or not when returning. I will add a comment.

Thanks,

Lizhi

> Best regards,
> Maciej
>
> > +
> > +    return drm_gem_vunmap(to_gobj(abo), map);
> >   }
> >     static struct dma_buf *amdxdna_gem_prime_export(struct 
> > drm_gem_object *gobj, int flags)
> > @@ -468,7 +458,7 @@ static void amdxdna_gem_obj_free(struct 
> > drm_gem_object *gobj)
> >       if (abo->type == AMDXDNA_BO_DEV_HEAP)
> >           drm_mm_takedown(&abo->mm);
> >   -    drm_gem_vunmap(gobj, &map);
> > +    amdxdna_gem_obj_vunmap(abo, &map);
> >       mutex_destroy(&abo->lock);
> >         if (is_import_bo(abo)) {
> > @@ -489,8 +479,8 @@ static const struct drm_gem_object_funcs 
> > amdxdna_gem_shmem_funcs = {
> >       .pin = drm_gem_shmem_object_pin,
> >       .unpin = drm_gem_shmem_object_unpin,
> >       .get_sg_table = drm_gem_shmem_object_get_sg_table,
> > -    .vmap = amdxdna_gem_obj_vmap,
> > -    .vunmap = amdxdna_gem_obj_vunmap,
> > +    .vmap = drm_gem_shmem_object_vmap,
> > +    .vunmap = drm_gem_shmem_object_vunmap,
> >       .mmap = amdxdna_gem_obj_mmap,
> >       .vm_ops = &drm_gem_shmem_vm_ops,
> >       .export = amdxdna_gem_prime_export,
> > @@ -692,7 +682,7 @@ amdxdna_drm_create_dev_heap(struct drm_device *dev,
> >       abo->mem.dev_addr = client->xdna->dev_info->dev_mem_base;
> >       drm_mm_init(&abo->mm, abo->mem.dev_addr, abo->mem.size);
> >   -    ret = drm_gem_vmap(to_gobj(abo), &map);
> > +    ret = amdxdna_gem_obj_vmap(abo, &map);
> >       if (ret) {
> >           XDNA_ERR(xdna, "Vmap heap bo failed, ret %d", ret);
> >           goto release_obj;
> > @@ -770,7 +760,7 @@ amdxdna_drm_create_cmd_bo(struct drm_device *dev,
> >       abo->type = AMDXDNA_BO_CMD;
> >       abo->client = filp->driver_priv;
> >   -    ret = drm_gem_vmap(to_gobj(abo), &map);
> > +    ret = amdxdna_gem_obj_vmap(abo, &map);
> >       if (ret) {
> >           XDNA_ERR(xdna, "Vmap cmd bo failed, ret %d", ret);
> >           goto release_obj;