cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

omap_gem_dmabuf.c (3577B)

      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}