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
19int 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;
43error_nomem:
44	dma_release_channel(dma->rxchan);
45error_rx:
46	dma_release_channel(dma->txchan);
47	return ret;
48}
49
50void 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
57int 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
78void 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
90int 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
109struct scatterlist *
110qce_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
134static 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
156int 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
174void 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
180int 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}
187