xref: /openbmc/linux/drivers/crypto/qce/dma.c (revision ebd09753)
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 }
135