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/device.h>
7 #include <linux/dmaengine.h>
8 #include <crypto/scatterwalk.h>
9 
10 #include "dma.h"
11 
12 static void qce_dma_release(void *data)
13 {
14 	struct qce_dma_data *dma = data;
15 
16 	dma_release_channel(dma->txchan);
17 	dma_release_channel(dma->rxchan);
18 	kfree(dma->result_buf);
19 }
20 
21 int devm_qce_dma_request(struct device *dev, struct qce_dma_data *dma)
22 {
23 	int ret;
24 
25 	dma->txchan = dma_request_chan(dev, "tx");
26 	if (IS_ERR(dma->txchan))
27 		return PTR_ERR(dma->txchan);
28 
29 	dma->rxchan = dma_request_chan(dev, "rx");
30 	if (IS_ERR(dma->rxchan)) {
31 		ret = PTR_ERR(dma->rxchan);
32 		goto error_rx;
33 	}
34 
35 	dma->result_buf = kmalloc(QCE_RESULT_BUF_SZ + QCE_IGNORE_BUF_SZ,
36 				  GFP_KERNEL);
37 	if (!dma->result_buf) {
38 		ret = -ENOMEM;
39 		goto error_nomem;
40 	}
41 
42 	dma->ignore_buf = dma->result_buf + QCE_RESULT_BUF_SZ;
43 
44 	return devm_add_action_or_reset(dev, qce_dma_release, dma);
45 
46 error_nomem:
47 	dma_release_channel(dma->rxchan);
48 error_rx:
49 	dma_release_channel(dma->txchan);
50 	return ret;
51 }
52 
53 struct scatterlist *
54 qce_sgtable_add(struct sg_table *sgt, struct scatterlist *new_sgl,
55 		unsigned int max_len)
56 {
57 	struct scatterlist *sg = sgt->sgl, *sg_last = NULL;
58 	unsigned int new_len;
59 
60 	while (sg) {
61 		if (!sg_page(sg))
62 			break;
63 		sg = sg_next(sg);
64 	}
65 
66 	if (!sg)
67 		return ERR_PTR(-EINVAL);
68 
69 	while (new_sgl && sg && max_len) {
70 		new_len = new_sgl->length > max_len ? max_len : new_sgl->length;
71 		sg_set_page(sg, sg_page(new_sgl), new_len, new_sgl->offset);
72 		sg_last = sg;
73 		sg = sg_next(sg);
74 		new_sgl = sg_next(new_sgl);
75 		max_len -= new_len;
76 	}
77 
78 	return sg_last;
79 }
80 
81 static int qce_dma_prep_sg(struct dma_chan *chan, struct scatterlist *sg,
82 			   int nents, unsigned long flags,
83 			   enum dma_transfer_direction dir,
84 			   dma_async_tx_callback cb, void *cb_param)
85 {
86 	struct dma_async_tx_descriptor *desc;
87 	dma_cookie_t cookie;
88 
89 	if (!sg || !nents)
90 		return -EINVAL;
91 
92 	desc = dmaengine_prep_slave_sg(chan, sg, nents, dir, flags);
93 	if (!desc)
94 		return -EINVAL;
95 
96 	desc->callback = cb;
97 	desc->callback_param = cb_param;
98 	cookie = dmaengine_submit(desc);
99 
100 	return dma_submit_error(cookie);
101 }
102 
103 int qce_dma_prep_sgs(struct qce_dma_data *dma, struct scatterlist *rx_sg,
104 		     int rx_nents, struct scatterlist *tx_sg, int tx_nents,
105 		     dma_async_tx_callback cb, void *cb_param)
106 {
107 	struct dma_chan *rxchan = dma->rxchan;
108 	struct dma_chan *txchan = dma->txchan;
109 	unsigned long flags = DMA_PREP_INTERRUPT | DMA_CTRL_ACK;
110 	int ret;
111 
112 	ret = qce_dma_prep_sg(rxchan, rx_sg, rx_nents, flags, DMA_MEM_TO_DEV,
113 			     NULL, NULL);
114 	if (ret)
115 		return ret;
116 
117 	return qce_dma_prep_sg(txchan, tx_sg, tx_nents, flags, DMA_DEV_TO_MEM,
118 			       cb, cb_param);
119 }
120 
121 void qce_dma_issue_pending(struct qce_dma_data *dma)
122 {
123 	dma_async_issue_pending(dma->rxchan);
124 	dma_async_issue_pending(dma->txchan);
125 }
126 
127 int qce_dma_terminate_all(struct qce_dma_data *dma)
128 {
129 	int ret;
130 
131 	ret = dmaengine_terminate_all(dma->rxchan);
132 	return ret ?: dmaengine_terminate_all(dma->txchan);
133 }
134