drivers/gpu/drm/xen/xen_drm_front_shbuf.h

   1 /* SPDX-License-Identifier: GPL-2.0 OR MIT */
   2
   3 /*
   4  *  Xen para-virtual DRM device
   5  *
   6  * Copyright (C) 2016-2018 EPAM Systems Inc.
   7  *
   8  * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
   9  */
  10
  11 #ifndef __XEN_DRM_FRONT_SHBUF_H_
  12 #define __XEN_DRM_FRONT_SHBUF_H_
  13
  14 #include <linux/kernel.h>
  15 #include <linux/scatterlist.h>
  16
  17 #include <xen/grant_table.h>
  18
  19 struct xen_drm_front_shbuf {
  20         /*
  21          * number of references granted for the backend use:
  22          *  - for allocated/imported dma-buf's this holds number of grant
  23          *    references for the page directory and pages of the buffer
  24          *  - for the buffer provided by the backend this holds number of
  25          *    grant references for the page directory as grant references for
  26          *    the buffer will be provided by the backend
  27          */
  28         int num_grefs;
  29         grant_ref_t *grefs;
  30         unsigned char *directory;
  31
  32         int num_pages;
  33         struct page **pages;
  34
  35         struct xenbus_device *xb_dev;
  36
  37         /* these are the ops used internally depending on be_alloc mode */
  38         const struct xen_drm_front_shbuf_ops *ops;
  39
  40         /* Xen map handles for the buffer allocated by the backend */
  41         grant_handle_t *backend_map_handles;
  42 };
  43
  44 struct xen_drm_front_shbuf_cfg {
  45         struct xenbus_device *xb_dev;
  46         size_t size;
  47         struct page **pages;
  48         bool be_alloc;
  49 };
  50
  51 struct xen_drm_front_shbuf *
  52 xen_drm_front_shbuf_alloc(struct xen_drm_front_shbuf_cfg *cfg);
  53
  54 grant_ref_t xen_drm_front_shbuf_get_dir_start(struct xen_drm_front_shbuf *buf);
  55
  56 int xen_drm_front_shbuf_map(struct xen_drm_front_shbuf *buf);
  57
  58 int xen_drm_front_shbuf_unmap(struct xen_drm_front_shbuf *buf);
  59
  60 void xen_drm_front_shbuf_flush(struct xen_drm_front_shbuf *buf);
  61
  62 void xen_drm_front_shbuf_free(struct xen_drm_front_shbuf *buf);
  63
  64 #endif /* __XEN_DRM_FRONT_SHBUF_H_ */