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, dir);
  27        if (IS_ERR(sg))
  28                return sg;
  29
  30        return sg;
  31}
  32
  33static void omap_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
  34                struct sg_table *sg, enum dma_data_direction dir)
  35{
  36        struct drm_gem_object *obj = attachment->dmabuf->priv;
  37        omap_gem_put_sg(obj, sg);
  38}
  39
  40static int omap_gem_dmabuf_begin_cpu_access(struct dma_buf *buffer,
  41                enum dma_data_direction dir)
  42{
  43        struct drm_gem_object *obj = buffer->priv;
  44        struct page **pages;
  45        if (omap_gem_flags(obj) & OMAP_BO_TILED_MASK) {
  46                /* TODO we would need to pin at least part of the buffer to
  47                 * get de-tiled view.  For now just reject it.
  48                 */
  49                return -ENOMEM;
  50        }
  51        /* make sure we have the pages: */
  52        return omap_gem_get_pages(obj, &pages, true);
  53}
  54
  55static int omap_gem_dmabuf_end_cpu_access(struct dma_buf *buffer,
  56                                          enum dma_data_direction dir)
  57{
  58        struct drm_gem_object *obj = buffer->priv;
  59        omap_gem_put_pages(obj);
  60        return 0;
  61}
  62
  63static int omap_gem_dmabuf_mmap(struct dma_buf *buffer,
  64                struct vm_area_struct *vma)
  65{
  66        struct drm_gem_object *obj = buffer->priv;
  67        int ret = 0;
  68
  69        ret = drm_gem_mmap_obj(obj, omap_gem_mmap_size(obj), vma);
  70        if (ret < 0)
  71                return ret;
  72
  73        return omap_gem_mmap_obj(obj, vma);
  74}
  75
  76static const struct dma_buf_ops omap_dmabuf_ops = {
  77        .map_dma_buf = omap_gem_map_dma_buf,
  78        .unmap_dma_buf = omap_gem_unmap_dma_buf,
  79        .release = drm_gem_dmabuf_release,
  80        .begin_cpu_access = omap_gem_dmabuf_begin_cpu_access,
  81        .end_cpu_access = omap_gem_dmabuf_end_cpu_access,
  82        .mmap = omap_gem_dmabuf_mmap,
  83};
  84
  85struct dma_buf *omap_gem_prime_export(struct drm_gem_object *obj, int flags)
  86{
  87        DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
  88
  89        exp_info.ops = &omap_dmabuf_ops;
  90        exp_info.size = omap_gem_mmap_size(obj);
  91        exp_info.flags = flags;
  92        exp_info.priv = obj;
  93        exp_info.resv = obj->resv;
  94
  95        return drm_gem_dmabuf_export(obj->dev, &exp_info);
  96}
  97
  98/* -----------------------------------------------------------------------------
  99 * DMABUF Import
 100 */
 101
 102struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev,
 103                                             struct dma_buf *dma_buf)
 104{
 105        struct dma_buf_attachment *attach;
 106        struct drm_gem_object *obj;
 107        struct sg_table *sgt;
 108        int ret;
 109
 110        if (dma_buf->ops == &omap_dmabuf_ops) {
 111                obj = dma_buf->priv;
 112                if (obj->dev == dev) {
 113                        /*
 114                         * Importing dmabuf exported from out own gem increases
 115                         * refcount on gem itself instead of f_count of dmabuf.
 116                         */
 117                        drm_gem_object_get(obj);
 118                        return obj;
 119                }
 120        }
 121
 122        attach = dma_buf_attach(dma_buf, dev->dev);
 123        if (IS_ERR(attach))
 124                return ERR_CAST(attach);
 125
 126        get_dma_buf(dma_buf);
 127
 128        sgt = dma_buf_map_attachment(attach, DMA_TO_DEVICE);
 129        if (IS_ERR(sgt)) {
 130                ret = PTR_ERR(sgt);
 131                goto fail_detach;
 132        }
 133
 134        obj = omap_gem_new_dmabuf(dev, dma_buf->size, sgt);
 135        if (IS_ERR(obj)) {
 136                ret = PTR_ERR(obj);
 137                goto fail_unmap;
 138        }
 139
 140        obj->import_attach = attach;
 141
 142        return obj;
 143
 144fail_unmap:
 145        dma_buf_unmap_attachment(attach, sgt, DMA_TO_DEVICE);
 146fail_detach:
 147        dma_buf_detach(dma_buf, attach);
 148        dma_buf_put(dma_buf);
 149
 150        return ERR_PTR(ret);
 151}
 152