drivers/crypto/qce/dma.c

   1 /*
   2  * Copyright (c) 2012-2014, The Linux Foundation. All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 and
   6  * only version 2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include <linux/dmaengine.h>
  15 #include <crypto/scatterwalk.h>
  16
  17 #include "dma.h"
  18
  19 int qce_dma_request(struct device *dev, struct qce_dma_data *dma)
  20 {
  21         int ret;
  22
  23         dma->txchan = dma_request_slave_channel_reason(dev, "tx");
  24         if (IS_ERR(dma->txchan))
  25                 return PTR_ERR(dma->txchan);
  26
  27         dma->rxchan = dma_request_slave_channel_reason(dev, "rx");
  28         if (IS_ERR(dma->rxchan)) {
  29                 ret = PTR_ERR(dma->rxchan);
  30                 goto error_rx;
  31         }
  32
  33         dma->result_buf = kmalloc(QCE_RESULT_BUF_SZ + QCE_IGNORE_BUF_SZ,
  34                                   GFP_KERNEL);
  35         if (!dma->result_buf) {
  36                 ret = -ENOMEM;
  37                 goto error_nomem;
  38         }
  39
  40         dma->ignore_buf = dma->result_buf + QCE_RESULT_BUF_SZ;
  41
  42         return 0;
  43 error_nomem:
  44         dma_release_channel(dma->rxchan);
  45 error_rx:
  46         dma_release_channel(dma->txchan);
  47         return ret;
  48 }
  49
  50 void qce_dma_release(struct qce_dma_data *dma)
  51 {
  52         dma_release_channel(dma->txchan);
  53         dma_release_channel(dma->rxchan);
  54         kfree(dma->result_buf);
  55 }
  56
  57 struct scatterlist *
  58 qce_sgtable_add(struct sg_table *sgt, struct scatterlist *new_sgl)
  59 {
  60         struct scatterlist *sg = sgt->sgl, *sg_last = NULL;
  61
  62         while (sg) {
  63                 if (!sg_page(sg))
  64                         break;
  65                 sg = sg_next(sg);
  66         }
  67
  68         if (!sg)
  69                 return ERR_PTR(-EINVAL);
  70
  71         while (new_sgl && sg) {
  72                 sg_set_page(sg, sg_page(new_sgl), new_sgl->length,
  73                             new_sgl->offset);
  74                 sg_last = sg;
  75                 sg = sg_next(sg);
  76                 new_sgl = sg_next(new_sgl);
  77         }
  78
  79         return sg_last;
  80 }
  81
  82 static int qce_dma_prep_sg(struct dma_chan *chan, struct scatterlist *sg,
  83                            int nents, unsigned long flags,
  84                            enum dma_transfer_direction dir,
  85                            dma_async_tx_callback cb, void *cb_param)
  86 {
  87         struct dma_async_tx_descriptor *desc;
  88         dma_cookie_t cookie;
  89
  90         if (!sg || !nents)
  91                 return -EINVAL;
  92
  93         desc = dmaengine_prep_slave_sg(chan, sg, nents, dir, flags);
  94         if (!desc)
  95                 return -EINVAL;
  96
  97         desc->callback = cb;
  98         desc->callback_param = cb_param;
  99         cookie = dmaengine_submit(desc);
 100
 101         return dma_submit_error(cookie);
 102 }
 103
 104 int qce_dma_prep_sgs(struct qce_dma_data *dma, struct scatterlist *rx_sg,
 105                      int rx_nents, struct scatterlist *tx_sg, int tx_nents,
 106                      dma_async_tx_callback cb, void *cb_param)
 107 {
 108         struct dma_chan *rxchan = dma->rxchan;
 109         struct dma_chan *txchan = dma->txchan;
 110         unsigned long flags = DMA_PREP_INTERRUPT | DMA_CTRL_ACK;
 111         int ret;
 112
 113         ret = qce_dma_prep_sg(rxchan, rx_sg, rx_nents, flags, DMA_MEM_TO_DEV,
 114                              NULL, NULL);
 115         if (ret)
 116                 return ret;
 117
 118         return qce_dma_prep_sg(txchan, tx_sg, tx_nents, flags, DMA_DEV_TO_MEM,
 119                                cb, cb_param);
 120 }
 121
 122 void qce_dma_issue_pending(struct qce_dma_data *dma)
 123 {
 124         dma_async_issue_pending(dma->rxchan);
 125         dma_async_issue_pending(dma->txchan);
 126 }
 127
 128 int qce_dma_terminate_all(struct qce_dma_data *dma)
 129 {
 130         int ret;
 131
 132         ret = dmaengine_terminate_all(dma->rxchan);
 133         return ret ?: dmaengine_terminate_all(dma->txchan);
 134 }