LXR linux/drivers/gpu/drm/omapdrm/omap_gem

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) 2011 Texas Instruments Incorporated - https://www.ti.com/
   4 * Author: Rob Clark <rob.clark@linaro.org>
   5 */
   6
   7#include <linux/dma-buf.h>
   8#include <linux/highmem.h>
   9
  10#include <drm/drm_prime.h>
  11
  12#include "omap_drv.h"
  13
  14MODULE_IMPORT_NS(DMA_BUF);
  15
  16/* -----------------------------------------------------------------------------
  17 * DMABUF Export
  18 */
  19
  20static struct sg_table *omap_gem_map_dma_buf(
  21                struct dma_buf_attachment *attachment,
  22                enum dma_data_direction dir)
  23{
  24        struct drm_gem_object *obj = attachment->dmabuf->priv;
  25        struct sg_table *sg;
  26        sg = omap_gem_get_sg(obj);
  27        if (IS_ERR(sg))
  28                return sg;
  29
  30        /* this must be after omap_gem_pin() to ensure we have pages attached */
  31        omap_gem_dma_sync_buffer(obj, dir);
  32
  33        return sg;
  34}
  35
  36static void omap_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
  37                struct sg_table *sg, enum dma_data_direction dir)
  38{
  39        struct drm_gem_object *obj = attachment->dmabuf->priv;
  40        omap_gem_put_sg(obj, sg);
  41}
  42
  43static int omap_gem_dmabuf_begin_cpu_access(struct dma_buf *buffer,
  44                enum dma_data_direction dir)
  45{
  46        struct drm_gem_object *obj = buffer->priv;
  47        struct page **pages;
  48        if (omap_gem_flags(obj) & OMAP_BO_TILED_MASK) {
  49                /* TODO we would need to pin at least part of the buffer to
  50                 * get de-tiled view.  For now just reject it.
  51                 */
  52                return -ENOMEM;
  53        }
  54        /* make sure we have the pages: */
  55        return omap_gem_get_pages(obj, &pages, true);
  56}
  57
  58static int omap_gem_dmabuf_end_cpu_access(struct dma_buf *buffer,
  59                                          enum dma_data_direction dir)
  60{
  61        struct drm_gem_object *obj = buffer->priv;
  62        omap_gem_put_pages(obj);
  63        return 0;
  64}
  65
  66static int omap_gem_dmabuf_mmap(struct dma_buf *buffer,
  67                struct vm_area_struct *vma)
  68{
  69        struct drm_gem_object *obj = buffer->priv;
  70        int ret = 0;
  71
  72        ret = drm_gem_mmap_obj(obj, omap_gem_mmap_size(obj), vma);
  73        if (ret < 0)
  74                return ret;
  75
  76        return omap_gem_mmap_obj(obj, vma);
  77}
  78
  79static const struct dma_buf_ops omap_dmabuf_ops = {
  80        .map_dma_buf = omap_gem_map_dma_buf,
  81        .unmap_dma_buf = omap_gem_unmap_dma_buf,
  82        .release = drm_gem_dmabuf_release,
  83        .begin_cpu_access = omap_gem_dmabuf_begin_cpu_access,
  84        .end_cpu_access = omap_gem_dmabuf_end_cpu_access,
  85        .mmap = omap_gem_dmabuf_mmap,
  86};
  87
  88struct dma_buf *omap_gem_prime_export(struct drm_gem_object *obj, int flags)
  89{
  90        DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
  91
  92        exp_info.ops = &omap_dmabuf_ops;
  93        exp_info.size = omap_gem_mmap_size(obj);
  94        exp_info.flags = flags;
  95        exp_info.priv = obj;
  96        exp_info.resv = obj->resv;
  97
  98        return drm_gem_dmabuf_export(obj->dev, &exp_info);
  99}
 100
 101/* -----------------------------------------------------------------------------
 102 * DMABUF Import
 103 */
 104
 105struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev,
 106                                             struct dma_buf *dma_buf)
 107{
 108        struct dma_buf_attachment *attach;
 109        struct drm_gem_object *obj;
 110        struct sg_table *sgt;
 111        int ret;
 112
 113        if (dma_buf->ops == &omap_dmabuf_ops) {
 114                obj = dma_buf->priv;
 115                if (obj->dev == dev) {
 116                        /*
 117                         * Importing dmabuf exported from out own gem increases
 118                         * refcount on gem itself instead of f_count of dmabuf.
 119                         */
 120                        drm_gem_object_get(obj);
 121                        return obj;
 122                }
 123        }
 124
 125        attach = dma_buf_attach(dma_buf, dev->dev);
 126        if (IS_ERR(attach))
 127                return ERR_CAST(attach);
 128
 129        get_dma_buf(dma_buf);
 130
 131        sgt = dma_buf_map_attachment(attach, DMA_TO_DEVICE);
 132        if (IS_ERR(sgt)) {
 133                ret = PTR_ERR(sgt);
 134                goto fail_detach;
 135        }
 136
 137        obj = omap_gem_new_dmabuf(dev, dma_buf->size, sgt);
 138        if (IS_ERR(obj)) {
 139                ret = PTR_ERR(obj);
 140                goto fail_unmap;
 141        }
 142
 143        obj->import_attach = attach;
 144
 145        return obj;
 146
 147fail_unmap:
 148        dma_buf_unmap_attachment(attach, sgt, DMA_TO_DEVICE);
 149fail_detach:
 150        dma_buf_detach(dma_buf, attach);
 151        dma_buf_put(dma_buf);
 152
 153        return ERR_PTR(ret);
 154}
 155