[PATCH v5 0/8] xen: dma-buf support for grant device

[Boris Ostrovsky]

On 07/20/2018 05:01 AM, Oleksandr Andrushchenko wrote:
> From: Oleksandr Andrushchenko <oleksandr_andrushchenko at epam.com>
>
> This work is in response to my previous attempt to introduce Xen/DRM
> zero-copy driver [1] to enable Linux dma-buf API [2] for Xen based
> frontends/backends. There is also an existing hyper_dmabuf approach
> available [3] which, if reworked to utilize the proposed solution,
> can greatly benefit as well.


Lot of warnings on  i386 build:

In file included from
/data/upstream/linux-xen/drivers/gpu/drm/xen/xen_drm_front.c:24:
/data/upstream/linux-xen/drivers/gpu/drm/xen/xen_drm_front.h: In
function ‘xen_drm_front_fb_to_cookie’:
/data/upstream/linux-xen/drivers/gpu/drm/xen/xen_drm_front.h:129:9:
warning: cast from pointer to integer of different size
[-Wpointer-to-int-cast]
  return (u64)fb;
         ^
/data/upstream/linux-xen/drivers/gpu/drm/xen/xen_drm_front.h: In
function ‘xen_drm_front_dbuf_to_cookie’:
/data/upstream/linux-xen/drivers/gpu/drm/xen/xen_drm_front.h:134:9:
warning: cast from pointer to integer of different size
[-Wpointer-to-int-cast]
  return (u64)gem_obj;
         ^
  CC [M]  net/netfilter/ipset/ip_set_hash_ipport.o
  CC      drivers/media/rc/keymaps/rc-tango.o
  CC [M]  drivers/gpu/drm/vmwgfx/vmwgfx_fifo.o
  AR      drivers/misc/built-in.a
In file included from
/data/upstream/linux-xen/drivers/gpu/drm/xen/xen_drm_front_kms.c:20:
/data/upstream/linux-xen/drivers/gpu/drm/xen/xen_drm_front.h: In
function ‘xen_drm_front_fb_to_cookie’:
  CC [M]  drivers/gpu/drm/xen/xen_drm_front_conn.o
/data/upstream/linux-xen/drivers/gpu/drm/xen/xen_drm_front.h:129:9:
warning: cast from pointer to integer of different size
[-Wpointer-to-int-cast]
  return (u64)fb;
(and more)



and then

data/upstream/linux-xen/drivers/xen/gntdev-dmabuf.c: In function
‘gntdev_ioctl_dmabuf_exp_from_refs’:
/data/upstream/linux-xen/drivers/xen/gntdev-dmabuf.c:503:6: warning:
‘args.fd’ may be used uninitialized in this function [-Wmaybe-uninitialized]
  *fd = args.fd;
  ~~~~^~~~~~~~~
/data/upstream/linux-xen/drivers/xen/gntdev-dmabuf.c:467:35: note:
‘args.fd’ was declared here
  struct gntdev_dmabuf_export_args args;
                                   ^~~~


-boris