LXR linux/drivers/gpu/drm/i915/i915

   1/*
   2 * SPDX-License-Identifier: MIT
   3 *
   4 * Copyright © 2016 Intel Corporation
   5 */
   6
   7#include "i915_scatterlist.h"
   8
   9bool i915_sg_trim(struct sg_table *orig_st)
  10{
  11        struct sg_table new_st;
  12        struct scatterlist *sg, *new_sg;
  13        unsigned int i;
  14
  15        if (orig_st->nents == orig_st->orig_nents)
  16                return false;
  17
  18        if (sg_alloc_table(&new_st, orig_st->nents, GFP_KERNEL | __GFP_NOWARN))
  19                return false;
  20
  21        new_sg = new_st.sgl;
  22        for_each_sg(orig_st->sgl, sg, orig_st->nents, i) {
  23                sg_set_page(new_sg, sg_page(sg), sg->length, 0);
  24                sg_dma_address(new_sg) = sg_dma_address(sg);
  25                sg_dma_len(new_sg) = sg_dma_len(sg);
  26
  27                new_sg = sg_next(new_sg);
  28        }
  29        GEM_BUG_ON(new_sg); /* Should walk exactly nents and hit the end */
  30
  31        sg_free_table(orig_st);
  32
  33        *orig_st = new_st;
  34        return true;
  35}
  36
  37#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
  38#include "selftests/scatterlist.c"
  39#endif
  40