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 int qce_mapsg(struct device *dev, struct scatterlist *sg, int nents,
  58               enum dma_data_direction dir, bool chained)
  59 {
  60         int err;
  61
  62         if (chained) {
  63                 while (sg) {
  64                         err = dma_map_sg(dev, sg, 1, dir);
  65                         if (!err)
  66                                 return -EFAULT;
  67                         sg = sg_next(sg);
  68                 }
  69         } else {
  70                 err = dma_map_sg(dev, sg, nents, dir);
  71                 if (!err)
  72                         return -EFAULT;
  73         }
  74
  75         return nents;
  76 }
  77
  78 void qce_unmapsg(struct device *dev, struct scatterlist *sg, int nents,
  79                  enum dma_data_direction dir, bool chained)
  80 {
  81         if (chained)
  82                 while (sg) {
  83                         dma_unmap_sg(dev, sg, 1, dir);
  84                         sg = sg_next(sg);
  85                 }
  86         else
  87                 dma_unmap_sg(dev, sg, nents, dir);
  88 }
  89
  90 int qce_countsg(struct scatterlist *sglist, int nbytes, bool *chained)
  91 {
  92         struct scatterlist *sg = sglist;
  93         int nents = 0;
  94
  95         if (chained)
  96                 *chained = false;
  97
  98         while (nbytes > 0 && sg) {
  99                 nents++;
 100                 nbytes -= sg->length;
 101                 if (!sg_is_last(sg) && (sg + 1)->length == 0 && chained)
 102                         *chained = true;
 103                 sg = sg_next(sg);
 104         }
 105
 106         return nents;
 107 }
 108
 109 struct scatterlist *
 110 qce_sgtable_add(struct sg_table *sgt, struct scatterlist *new_sgl)
 111 {
 112         struct scatterlist *sg = sgt->sgl, *sg_last = NULL;
 113
 114         while (sg) {
 115                 if (!sg_page(sg))
 116                         break;
 117                 sg = sg_next(sg);
 118         }
 119
 120         if (!sg)
 121                 return ERR_PTR(-EINVAL);
 122
 123         while (new_sgl && sg) {
 124                 sg_set_page(sg, sg_page(new_sgl), new_sgl->length,
 125                             new_sgl->offset);
 126                 sg_last = sg;
 127                 sg = sg_next(sg);
 128                 new_sgl = sg_next(new_sgl);
 129         }
 130
 131         return sg_last;
 132 }
 133
 134 static int qce_dma_prep_sg(struct dma_chan *chan, struct scatterlist *sg,
 135                            int nents, unsigned long flags,
 136                            enum dma_transfer_direction dir,
 137                            dma_async_tx_callback cb, void *cb_param)
 138 {
 139         struct dma_async_tx_descriptor *desc;
 140         dma_cookie_t cookie;
 141
 142         if (!sg || !nents)
 143                 return -EINVAL;
 144
 145         desc = dmaengine_prep_slave_sg(chan, sg, nents, dir, flags);
 146         if (!desc)
 147                 return -EINVAL;
 148
 149         desc->callback = cb;
 150         desc->callback_param = cb_param;
 151         cookie = dmaengine_submit(desc);
 152
 153         return dma_submit_error(cookie);
 154 }
 155
 156 int qce_dma_prep_sgs(struct qce_dma_data *dma, struct scatterlist *rx_sg,
 157                      int rx_nents, struct scatterlist *tx_sg, int tx_nents,
 158                      dma_async_tx_callback cb, void *cb_param)
 159 {
 160         struct dma_chan *rxchan = dma->rxchan;
 161         struct dma_chan *txchan = dma->txchan;
 162         unsigned long flags = DMA_PREP_INTERRUPT | DMA_CTRL_ACK;
 163         int ret;
 164
 165         ret = qce_dma_prep_sg(rxchan, rx_sg, rx_nents, flags, DMA_MEM_TO_DEV,
 166                              NULL, NULL);
 167         if (ret)
 168                 return ret;
 169
 170         return qce_dma_prep_sg(txchan, tx_sg, tx_nents, flags, DMA_DEV_TO_MEM,
 171                                cb, cb_param);
 172 }
 173
 174 void qce_dma_issue_pending(struct qce_dma_data *dma)
 175 {
 176         dma_async_issue_pending(dma->rxchan);
 177         dma_async_issue_pending(dma->txchan);
 178 }
 179
 180 int qce_dma_terminate_all(struct qce_dma_data *dma)
 181 {
 182         int ret;
 183
 184         ret = dmaengine_terminate_all(dma->rxchan);
 185         return ret ?: dmaengine_terminate_all(dma->txchan);
 186 }