cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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dma.c (2931B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Copyright (c) 2012-2014, The Linux Foundation. All rights reserved.
      4 */
      5
      6#include <linux/dmaengine.h>
      7#include <crypto/scatterwalk.h>
      8
      9#include "dma.h"
     10
     11int qce_dma_request(struct device *dev, struct qce_dma_data *dma)
     12{
     13	int ret;
     14
     15	dma->txchan = dma_request_chan(dev, "tx");
     16	if (IS_ERR(dma->txchan))
     17		return PTR_ERR(dma->txchan);
     18
     19	dma->rxchan = dma_request_chan(dev, "rx");
     20	if (IS_ERR(dma->rxchan)) {
     21		ret = PTR_ERR(dma->rxchan);
     22		goto error_rx;
     23	}
     24
     25	dma->result_buf = kmalloc(QCE_RESULT_BUF_SZ + QCE_IGNORE_BUF_SZ,
     26				  GFP_KERNEL);
     27	if (!dma->result_buf) {
     28		ret = -ENOMEM;
     29		goto error_nomem;
     30	}
     31
     32	dma->ignore_buf = dma->result_buf + QCE_RESULT_BUF_SZ;
     33
     34	return 0;
     35error_nomem:
     36	dma_release_channel(dma->rxchan);
     37error_rx:
     38	dma_release_channel(dma->txchan);
     39	return ret;
     40}
     41
     42void qce_dma_release(struct qce_dma_data *dma)
     43{
     44	dma_release_channel(dma->txchan);
     45	dma_release_channel(dma->rxchan);
     46	kfree(dma->result_buf);
     47}
     48
     49struct scatterlist *
     50qce_sgtable_add(struct sg_table *sgt, struct scatterlist *new_sgl,
     51		unsigned int max_len)
     52{
     53	struct scatterlist *sg = sgt->sgl, *sg_last = NULL;
     54	unsigned int new_len;
     55
     56	while (sg) {
     57		if (!sg_page(sg))
     58			break;
     59		sg = sg_next(sg);
     60	}
     61
     62	if (!sg)
     63		return ERR_PTR(-EINVAL);
     64
     65	while (new_sgl && sg && max_len) {
     66		new_len = new_sgl->length > max_len ? max_len : new_sgl->length;
     67		sg_set_page(sg, sg_page(new_sgl), new_len, new_sgl->offset);
     68		sg_last = sg;
     69		sg = sg_next(sg);
     70		new_sgl = sg_next(new_sgl);
     71		max_len -= new_len;
     72	}
     73
     74	return sg_last;
     75}
     76
     77static int qce_dma_prep_sg(struct dma_chan *chan, struct scatterlist *sg,
     78			   int nents, unsigned long flags,
     79			   enum dma_transfer_direction dir,
     80			   dma_async_tx_callback cb, void *cb_param)
     81{
     82	struct dma_async_tx_descriptor *desc;
     83	dma_cookie_t cookie;
     84
     85	if (!sg || !nents)
     86		return -EINVAL;
     87
     88	desc = dmaengine_prep_slave_sg(chan, sg, nents, dir, flags);
     89	if (!desc)
     90		return -EINVAL;
     91
     92	desc->callback = cb;
     93	desc->callback_param = cb_param;
     94	cookie = dmaengine_submit(desc);
     95
     96	return dma_submit_error(cookie);
     97}
     98
     99int qce_dma_prep_sgs(struct qce_dma_data *dma, struct scatterlist *rx_sg,
    100		     int rx_nents, struct scatterlist *tx_sg, int tx_nents,
    101		     dma_async_tx_callback cb, void *cb_param)
    102{
    103	struct dma_chan *rxchan = dma->rxchan;
    104	struct dma_chan *txchan = dma->txchan;
    105	unsigned long flags = DMA_PREP_INTERRUPT | DMA_CTRL_ACK;
    106	int ret;
    107
    108	ret = qce_dma_prep_sg(rxchan, rx_sg, rx_nents, flags, DMA_MEM_TO_DEV,
    109			     NULL, NULL);
    110	if (ret)
    111		return ret;
    112
    113	return qce_dma_prep_sg(txchan, tx_sg, tx_nents, flags, DMA_DEV_TO_MEM,
    114			       cb, cb_param);
    115}
    116
    117void qce_dma_issue_pending(struct qce_dma_data *dma)
    118{
    119	dma_async_issue_pending(dma->rxchan);
    120	dma_async_issue_pending(dma->txchan);
    121}
    122
    123int qce_dma_terminate_all(struct qce_dma_data *dma)
    124{
    125	int ret;
    126
    127	ret = dmaengine_terminate_all(dma->rxchan);
    128	return ret ?: dmaengine_terminate_all(dma->txchan);
    129}