xref: /linux/drivers/dma/idxd/dma.c (revision 0e9b70c1e3623fa110fb6be553e644524228ef60)
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 			   bool free_desc)
26 {
27 	struct idxd_device *idxd = desc->wq->idxd;
28 	struct dma_async_tx_descriptor *tx;
29 	struct dmaengine_result res;
30 	int complete = 1;
31 
32 	if (desc->completion->status == DSA_COMP_SUCCESS) {
33 		res.result = DMA_TRANS_NOERROR;
34 	} else if (desc->completion->status) {
35 		if (idxd->request_int_handles && comp_type != IDXD_COMPLETE_ABORT &&
36 		    desc->completion->status == DSA_COMP_INT_HANDLE_INVAL &&
37 		    idxd_queue_int_handle_resubmit(desc))
38 			return;
39 		res.result = DMA_TRANS_WRITE_FAILED;
40 	} else if (comp_type == IDXD_COMPLETE_ABORT) {
41 		res.result = DMA_TRANS_ABORTED;
42 	} else {
43 		complete = 0;
44 	}
45 
46 	tx = &desc->txd;
47 	if (complete && tx->cookie) {
48 		dma_cookie_complete(tx);
49 		dma_descriptor_unmap(tx);
50 		dmaengine_desc_get_callback_invoke(tx, &res);
51 		tx->callback = NULL;
52 		tx->callback_result = NULL;
53 	}
54 
55 	if (free_desc)
56 		idxd_free_desc(desc->wq, desc);
57 }
58 
59 static void op_flag_setup(unsigned long flags, u32 *desc_flags)
60 {
61 	*desc_flags = IDXD_OP_FLAG_CRAV | IDXD_OP_FLAG_RCR;
62 	if (flags & DMA_PREP_INTERRUPT)
63 		*desc_flags |= IDXD_OP_FLAG_RCI;
64 }
65 
66 static inline void idxd_prep_desc_common(struct idxd_wq *wq,
67 					 struct dsa_hw_desc *hw, char opcode,
68 					 u64 addr_f1, u64 addr_f2, u64 len,
69 					 u64 compl, u32 flags)
70 {
71 	hw->flags = flags;
72 	hw->opcode = opcode;
73 	hw->src_addr = addr_f1;
74 	hw->dst_addr = addr_f2;
75 	hw->xfer_size = len;
76 	/*
77 	 * For dedicated WQ, this field is ignored and HW will use the WQCFG.priv
78 	 * field instead. This field should be set to 1 for kernel descriptors.
79 	 */
80 	hw->priv = 1;
81 	hw->completion_addr = compl;
82 }
83 
84 static struct dma_async_tx_descriptor *
85 idxd_dma_prep_interrupt(struct dma_chan *c, unsigned long flags)
86 {
87 	struct idxd_wq *wq = to_idxd_wq(c);
88 	u32 desc_flags;
89 	struct idxd_desc *desc;
90 
91 	if (wq->state != IDXD_WQ_ENABLED)
92 		return NULL;
93 
94 	op_flag_setup(flags, &desc_flags);
95 	desc = idxd_alloc_desc(wq, IDXD_OP_BLOCK);
96 	if (IS_ERR(desc))
97 		return NULL;
98 
99 	idxd_prep_desc_common(wq, desc->hw, DSA_OPCODE_NOOP,
100 			      0, 0, 0, desc->compl_dma, desc_flags);
101 	desc->txd.flags = flags;
102 	return &desc->txd;
103 }
104 
105 static struct dma_async_tx_descriptor *
106 idxd_dma_submit_memcpy(struct dma_chan *c, dma_addr_t dma_dest,
107 		       dma_addr_t dma_src, size_t len, unsigned long flags)
108 {
109 	struct idxd_wq *wq = to_idxd_wq(c);
110 	u32 desc_flags;
111 	struct idxd_device *idxd = wq->idxd;
112 	struct idxd_desc *desc;
113 
114 	if (wq->state != IDXD_WQ_ENABLED)
115 		return NULL;
116 
117 	if (len > idxd->max_xfer_bytes)
118 		return NULL;
119 
120 	op_flag_setup(flags, &desc_flags);
121 	desc = idxd_alloc_desc(wq, IDXD_OP_BLOCK);
122 	if (IS_ERR(desc))
123 		return NULL;
124 
125 	idxd_prep_desc_common(wq, desc->hw, DSA_OPCODE_MEMMOVE,
126 			      dma_src, dma_dest, len, desc->compl_dma,
127 			      desc_flags);
128 
129 	desc->txd.flags = flags;
130 
131 	return &desc->txd;
132 }
133 
134 static int idxd_dma_alloc_chan_resources(struct dma_chan *chan)
135 {
136 	struct idxd_wq *wq = to_idxd_wq(chan);
137 	struct device *dev = &wq->idxd->pdev->dev;
138 
139 	idxd_wq_get(wq);
140 	dev_dbg(dev, "%s: client_count: %d\n", __func__,
141 		idxd_wq_refcount(wq));
142 	return 0;
143 }
144 
145 static void idxd_dma_free_chan_resources(struct dma_chan *chan)
146 {
147 	struct idxd_wq *wq = to_idxd_wq(chan);
148 	struct device *dev = &wq->idxd->pdev->dev;
149 
150 	idxd_wq_put(wq);
151 	dev_dbg(dev, "%s: client_count: %d\n", __func__,
152 		idxd_wq_refcount(wq));
153 }
154 
155 static enum dma_status idxd_dma_tx_status(struct dma_chan *dma_chan,
156 					  dma_cookie_t cookie,
157 					  struct dma_tx_state *txstate)
158 {
159 	return DMA_OUT_OF_ORDER;
160 }
161 
162 /*
163  * issue_pending() does not need to do anything since tx_submit() does the job
164  * already.
165  */
166 static void idxd_dma_issue_pending(struct dma_chan *dma_chan)
167 {
168 }
169 
170 static dma_cookie_t idxd_dma_tx_submit(struct dma_async_tx_descriptor *tx)
171 {
172 	struct dma_chan *c = tx->chan;
173 	struct idxd_wq *wq = to_idxd_wq(c);
174 	dma_cookie_t cookie;
175 	int rc;
176 	struct idxd_desc *desc = container_of(tx, struct idxd_desc, txd);
177 
178 	cookie = dma_cookie_assign(tx);
179 
180 	rc = idxd_submit_desc(wq, desc);
181 	if (rc < 0) {
182 		idxd_free_desc(wq, desc);
183 		return rc;
184 	}
185 
186 	return cookie;
187 }
188 
189 static void idxd_dma_release(struct dma_device *device)
190 {
191 	struct idxd_dma_dev *idxd_dma = container_of(device, struct idxd_dma_dev, dma);
192 
193 	kfree(idxd_dma);
194 }
195 
196 int idxd_register_dma_device(struct idxd_device *idxd)
197 {
198 	struct idxd_dma_dev *idxd_dma;
199 	struct dma_device *dma;
200 	struct device *dev = &idxd->pdev->dev;
201 	int rc;
202 
203 	idxd_dma = kzalloc_node(sizeof(*idxd_dma), GFP_KERNEL, dev_to_node(dev));
204 	if (!idxd_dma)
205 		return -ENOMEM;
206 
207 	dma = &idxd_dma->dma;
208 	INIT_LIST_HEAD(&dma->channels);
209 	dma->dev = dev;
210 
211 	dma_cap_set(DMA_INTERRUPT, dma->cap_mask);
212 	dma_cap_set(DMA_PRIVATE, dma->cap_mask);
213 	dma_cap_set(DMA_COMPLETION_NO_ORDER, dma->cap_mask);
214 	dma->device_release = idxd_dma_release;
215 
216 	dma->device_prep_dma_interrupt = idxd_dma_prep_interrupt;
217 	if (idxd->hw.opcap.bits[0] & IDXD_OPCAP_MEMMOVE) {
218 		dma_cap_set(DMA_MEMCPY, dma->cap_mask);
219 		dma->device_prep_dma_memcpy = idxd_dma_submit_memcpy;
220 	}
221 
222 	dma->device_tx_status = idxd_dma_tx_status;
223 	dma->device_issue_pending = idxd_dma_issue_pending;
224 	dma->device_alloc_chan_resources = idxd_dma_alloc_chan_resources;
225 	dma->device_free_chan_resources = idxd_dma_free_chan_resources;
226 
227 	rc = dma_async_device_register(dma);
228 	if (rc < 0) {
229 		kfree(idxd_dma);
230 		return rc;
231 	}
232 
233 	idxd_dma->idxd = idxd;
234 	/*
235 	 * This pointer is protected by the refs taken by the dma_chan. It will remain valid
236 	 * as long as there are outstanding channels.
237 	 */
238 	idxd->idxd_dma = idxd_dma;
239 	return 0;
240 }
241 
242 void idxd_unregister_dma_device(struct idxd_device *idxd)
243 {
244 	dma_async_device_unregister(&idxd->idxd_dma->dma);
245 }
246 
247 static int idxd_register_dma_channel(struct idxd_wq *wq)
248 {
249 	struct idxd_device *idxd = wq->idxd;
250 	struct dma_device *dma = &idxd->idxd_dma->dma;
251 	struct device *dev = &idxd->pdev->dev;
252 	struct idxd_dma_chan *idxd_chan;
253 	struct dma_chan *chan;
254 	int rc, i;
255 
256 	idxd_chan = kzalloc_node(sizeof(*idxd_chan), GFP_KERNEL, dev_to_node(dev));
257 	if (!idxd_chan)
258 		return -ENOMEM;
259 
260 	chan = &idxd_chan->chan;
261 	chan->device = dma;
262 	list_add_tail(&chan->device_node, &dma->channels);
263 
264 	for (i = 0; i < wq->num_descs; i++) {
265 		struct idxd_desc *desc = wq->descs[i];
266 
267 		dma_async_tx_descriptor_init(&desc->txd, chan);
268 		desc->txd.tx_submit = idxd_dma_tx_submit;
269 	}
270 
271 	rc = dma_async_device_channel_register(dma, chan);
272 	if (rc < 0) {
273 		kfree(idxd_chan);
274 		return rc;
275 	}
276 
277 	wq->idxd_chan = idxd_chan;
278 	idxd_chan->wq = wq;
279 	get_device(wq_confdev(wq));
280 
281 	return 0;
282 }
283 
284 static void idxd_unregister_dma_channel(struct idxd_wq *wq)
285 {
286 	struct idxd_dma_chan *idxd_chan = wq->idxd_chan;
287 	struct dma_chan *chan = &idxd_chan->chan;
288 	struct idxd_dma_dev *idxd_dma = wq->idxd->idxd_dma;
289 
290 	dma_async_device_channel_unregister(&idxd_dma->dma, chan);
291 	list_del(&chan->device_node);
292 	kfree(wq->idxd_chan);
293 	wq->idxd_chan = NULL;
294 	put_device(wq_confdev(wq));
295 }
296 
297 static int idxd_dmaengine_drv_probe(struct idxd_dev *idxd_dev)
298 {
299 	struct device *dev = &idxd_dev->conf_dev;
300 	struct idxd_wq *wq = idxd_dev_to_wq(idxd_dev);
301 	struct idxd_device *idxd = wq->idxd;
302 	int rc;
303 
304 	if (idxd->state != IDXD_DEV_ENABLED)
305 		return -ENXIO;
306 
307 	mutex_lock(&wq->wq_lock);
308 	wq->type = IDXD_WQT_KERNEL;
309 
310 	rc = drv_enable_wq(wq);
311 	if (rc < 0) {
312 		dev_dbg(dev, "Enable wq %d failed: %d\n", wq->id, rc);
313 		rc = -ENXIO;
314 		goto err;
315 	}
316 
317 	rc = idxd_register_dma_channel(wq);
318 	if (rc < 0) {
319 		idxd->cmd_status = IDXD_SCMD_DMA_CHAN_ERR;
320 		dev_dbg(dev, "Failed to register dma channel\n");
321 		goto err_dma;
322 	}
323 
324 	idxd->cmd_status = 0;
325 	mutex_unlock(&wq->wq_lock);
326 	return 0;
327 
328 err_dma:
329 	drv_disable_wq(wq);
330 err:
331 	wq->type = IDXD_WQT_NONE;
332 	mutex_unlock(&wq->wq_lock);
333 	return rc;
334 }
335 
336 static void idxd_dmaengine_drv_remove(struct idxd_dev *idxd_dev)
337 {
338 	struct idxd_wq *wq = idxd_dev_to_wq(idxd_dev);
339 
340 	mutex_lock(&wq->wq_lock);
341 	__idxd_wq_quiesce(wq);
342 	idxd_unregister_dma_channel(wq);
343 	drv_disable_wq(wq);
344 	mutex_unlock(&wq->wq_lock);
345 }
346 
347 static enum idxd_dev_type dev_types[] = {
348 	IDXD_DEV_WQ,
349 	IDXD_DEV_NONE,
350 };
351 
352 struct idxd_device_driver idxd_dmaengine_drv = {
353 	.probe = idxd_dmaengine_drv_probe,
354 	.remove = idxd_dmaengine_drv_remove,
355 	.name = "dmaengine",
356 	.type = dev_types,
357 };
358 EXPORT_SYMBOL_GPL(idxd_dmaengine_drv);
359