xref: /openbmc/linux/drivers/dma/idxd/dma.c (revision 28dce2c4)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright(c) 2019 Intel Corporation. All rights rsvd. */
3 #include <linux/init.h>
4 #include <linux/kernel.h>
5 #include <linux/module.h>
6 #include <linux/pci.h>
7 #include <linux/device.h>
8 #include <linux/io-64-nonatomic-lo-hi.h>
9 #include <linux/dmaengine.h>
10 #include <uapi/linux/idxd.h>
11 #include "../dmaengine.h"
12 #include "registers.h"
13 #include "idxd.h"
14 
15 static inline struct idxd_wq *to_idxd_wq(struct dma_chan *c)
16 {
17 	struct idxd_dma_chan *idxd_chan;
18 
19 	idxd_chan = container_of(c, struct idxd_dma_chan, chan);
20 	return idxd_chan->wq;
21 }
22 
23 void idxd_dma_complete_txd(struct idxd_desc *desc,
24 			   enum idxd_complete_type comp_type)
25 {
26 	struct dma_async_tx_descriptor *tx;
27 	struct dmaengine_result res;
28 	int complete = 1;
29 
30 	if (desc->completion->status == DSA_COMP_SUCCESS)
31 		res.result = DMA_TRANS_NOERROR;
32 	else if (desc->completion->status)
33 		res.result = DMA_TRANS_WRITE_FAILED;
34 	else if (comp_type == IDXD_COMPLETE_ABORT)
35 		res.result = DMA_TRANS_ABORTED;
36 	else
37 		complete = 0;
38 
39 	tx = &desc->txd;
40 	if (complete && tx->cookie) {
41 		dma_cookie_complete(tx);
42 		dma_descriptor_unmap(tx);
43 		dmaengine_desc_get_callback_invoke(tx, &res);
44 		tx->callback = NULL;
45 		tx->callback_result = NULL;
46 	}
47 }
48 
49 static void op_flag_setup(unsigned long flags, u32 *desc_flags)
50 {
51 	*desc_flags = IDXD_OP_FLAG_CRAV | IDXD_OP_FLAG_RCR;
52 	if (flags & DMA_PREP_INTERRUPT)
53 		*desc_flags |= IDXD_OP_FLAG_RCI;
54 }
55 
56 static inline void set_completion_address(struct idxd_desc *desc,
57 					  u64 *compl_addr)
58 {
59 		*compl_addr = desc->compl_dma;
60 }
61 
62 static inline void idxd_prep_desc_common(struct idxd_wq *wq,
63 					 struct dsa_hw_desc *hw, char opcode,
64 					 u64 addr_f1, u64 addr_f2, u64 len,
65 					 u64 compl, u32 flags)
66 {
67 	hw->flags = flags;
68 	hw->opcode = opcode;
69 	hw->src_addr = addr_f1;
70 	hw->dst_addr = addr_f2;
71 	hw->xfer_size = len;
72 	hw->priv = !!(wq->type == IDXD_WQT_KERNEL);
73 	hw->completion_addr = compl;
74 }
75 
76 static struct dma_async_tx_descriptor *
77 idxd_dma_submit_memcpy(struct dma_chan *c, dma_addr_t dma_dest,
78 		       dma_addr_t dma_src, size_t len, unsigned long flags)
79 {
80 	struct idxd_wq *wq = to_idxd_wq(c);
81 	u32 desc_flags;
82 	struct idxd_device *idxd = wq->idxd;
83 	struct idxd_desc *desc;
84 
85 	if (wq->state != IDXD_WQ_ENABLED)
86 		return NULL;
87 
88 	if (len > idxd->max_xfer_bytes)
89 		return NULL;
90 
91 	op_flag_setup(flags, &desc_flags);
92 	desc = idxd_alloc_desc(wq, IDXD_OP_BLOCK);
93 	if (IS_ERR(desc))
94 		return NULL;
95 
96 	idxd_prep_desc_common(wq, desc->hw, DSA_OPCODE_MEMMOVE,
97 			      dma_src, dma_dest, len, desc->compl_dma,
98 			      desc_flags);
99 
100 	desc->txd.flags = flags;
101 
102 	return &desc->txd;
103 }
104 
105 static int idxd_dma_alloc_chan_resources(struct dma_chan *chan)
106 {
107 	struct idxd_wq *wq = to_idxd_wq(chan);
108 	struct device *dev = &wq->idxd->pdev->dev;
109 
110 	idxd_wq_get(wq);
111 	dev_dbg(dev, "%s: client_count: %d\n", __func__,
112 		idxd_wq_refcount(wq));
113 	return 0;
114 }
115 
116 static void idxd_dma_free_chan_resources(struct dma_chan *chan)
117 {
118 	struct idxd_wq *wq = to_idxd_wq(chan);
119 	struct device *dev = &wq->idxd->pdev->dev;
120 
121 	idxd_wq_put(wq);
122 	dev_dbg(dev, "%s: client_count: %d\n", __func__,
123 		idxd_wq_refcount(wq));
124 }
125 
126 static enum dma_status idxd_dma_tx_status(struct dma_chan *dma_chan,
127 					  dma_cookie_t cookie,
128 					  struct dma_tx_state *txstate)
129 {
130 	return DMA_OUT_OF_ORDER;
131 }
132 
133 /*
134  * issue_pending() does not need to do anything since tx_submit() does the job
135  * already.
136  */
137 static void idxd_dma_issue_pending(struct dma_chan *dma_chan)
138 {
139 }
140 
141 static dma_cookie_t idxd_dma_tx_submit(struct dma_async_tx_descriptor *tx)
142 {
143 	struct dma_chan *c = tx->chan;
144 	struct idxd_wq *wq = to_idxd_wq(c);
145 	dma_cookie_t cookie;
146 	int rc;
147 	struct idxd_desc *desc = container_of(tx, struct idxd_desc, txd);
148 
149 	cookie = dma_cookie_assign(tx);
150 
151 	rc = idxd_submit_desc(wq, desc);
152 	if (rc < 0) {
153 		idxd_free_desc(wq, desc);
154 		return rc;
155 	}
156 
157 	return cookie;
158 }
159 
160 static void idxd_dma_release(struct dma_device *device)
161 {
162 	struct idxd_dma_dev *idxd_dma = container_of(device, struct idxd_dma_dev, dma);
163 
164 	kfree(idxd_dma);
165 }
166 
167 int idxd_register_dma_device(struct idxd_device *idxd)
168 {
169 	struct idxd_dma_dev *idxd_dma;
170 	struct dma_device *dma;
171 	struct device *dev = &idxd->pdev->dev;
172 	int rc;
173 
174 	idxd_dma = kzalloc_node(sizeof(*idxd_dma), GFP_KERNEL, dev_to_node(dev));
175 	if (!idxd_dma)
176 		return -ENOMEM;
177 
178 	dma = &idxd_dma->dma;
179 	INIT_LIST_HEAD(&dma->channels);
180 	dma->dev = dev;
181 
182 	dma_cap_set(DMA_PRIVATE, dma->cap_mask);
183 	dma_cap_set(DMA_COMPLETION_NO_ORDER, dma->cap_mask);
184 	dma->device_release = idxd_dma_release;
185 
186 	if (idxd->hw.opcap.bits[0] & IDXD_OPCAP_MEMMOVE) {
187 		dma_cap_set(DMA_MEMCPY, dma->cap_mask);
188 		dma->device_prep_dma_memcpy = idxd_dma_submit_memcpy;
189 	}
190 
191 	dma->device_tx_status = idxd_dma_tx_status;
192 	dma->device_issue_pending = idxd_dma_issue_pending;
193 	dma->device_alloc_chan_resources = idxd_dma_alloc_chan_resources;
194 	dma->device_free_chan_resources = idxd_dma_free_chan_resources;
195 
196 	rc = dma_async_device_register(dma);
197 	if (rc < 0) {
198 		kfree(idxd_dma);
199 		return rc;
200 	}
201 
202 	idxd_dma->idxd = idxd;
203 	/*
204 	 * This pointer is protected by the refs taken by the dma_chan. It will remain valid
205 	 * as long as there are outstanding channels.
206 	 */
207 	idxd->idxd_dma = idxd_dma;
208 	return 0;
209 }
210 
211 void idxd_unregister_dma_device(struct idxd_device *idxd)
212 {
213 	dma_async_device_unregister(&idxd->idxd_dma->dma);
214 }
215 
216 int idxd_register_dma_channel(struct idxd_wq *wq)
217 {
218 	struct idxd_device *idxd = wq->idxd;
219 	struct dma_device *dma = &idxd->idxd_dma->dma;
220 	struct device *dev = &idxd->pdev->dev;
221 	struct idxd_dma_chan *idxd_chan;
222 	struct dma_chan *chan;
223 	int rc, i;
224 
225 	idxd_chan = kzalloc_node(sizeof(*idxd_chan), GFP_KERNEL, dev_to_node(dev));
226 	if (!idxd_chan)
227 		return -ENOMEM;
228 
229 	chan = &idxd_chan->chan;
230 	chan->device = dma;
231 	list_add_tail(&chan->device_node, &dma->channels);
232 
233 	for (i = 0; i < wq->num_descs; i++) {
234 		struct idxd_desc *desc = wq->descs[i];
235 
236 		dma_async_tx_descriptor_init(&desc->txd, chan);
237 		desc->txd.tx_submit = idxd_dma_tx_submit;
238 	}
239 
240 	rc = dma_async_device_channel_register(dma, chan);
241 	if (rc < 0) {
242 		kfree(idxd_chan);
243 		return rc;
244 	}
245 
246 	wq->idxd_chan = idxd_chan;
247 	idxd_chan->wq = wq;
248 	get_device(&wq->conf_dev);
249 
250 	return 0;
251 }
252 
253 void idxd_unregister_dma_channel(struct idxd_wq *wq)
254 {
255 	struct idxd_dma_chan *idxd_chan = wq->idxd_chan;
256 	struct dma_chan *chan = &idxd_chan->chan;
257 	struct idxd_dma_dev *idxd_dma = wq->idxd->idxd_dma;
258 
259 	dma_async_device_channel_unregister(&idxd_dma->dma, chan);
260 	list_del(&chan->device_node);
261 	kfree(wq->idxd_chan);
262 	wq->idxd_chan = NULL;
263 	put_device(&wq->conf_dev);
264 }
265