xref: /openbmc/linux/drivers/dma/idxd/dma.c (revision dfc66bef)
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 	/*
73 	 * For dedicated WQ, this field is ignored and HW will use the WQCFG.priv
74 	 * field instead. This field should be set to 1 for kernel descriptors.
75 	 */
76 	hw->priv = 1;
77 	hw->completion_addr = compl;
78 }
79 
80 static struct dma_async_tx_descriptor *
81 idxd_dma_submit_memcpy(struct dma_chan *c, dma_addr_t dma_dest,
82 		       dma_addr_t dma_src, size_t len, unsigned long flags)
83 {
84 	struct idxd_wq *wq = to_idxd_wq(c);
85 	u32 desc_flags;
86 	struct idxd_device *idxd = wq->idxd;
87 	struct idxd_desc *desc;
88 
89 	if (wq->state != IDXD_WQ_ENABLED)
90 		return NULL;
91 
92 	if (len > idxd->max_xfer_bytes)
93 		return NULL;
94 
95 	op_flag_setup(flags, &desc_flags);
96 	desc = idxd_alloc_desc(wq, IDXD_OP_BLOCK);
97 	if (IS_ERR(desc))
98 		return NULL;
99 
100 	idxd_prep_desc_common(wq, desc->hw, DSA_OPCODE_MEMMOVE,
101 			      dma_src, dma_dest, len, desc->compl_dma,
102 			      desc_flags);
103 
104 	desc->txd.flags = flags;
105 
106 	return &desc->txd;
107 }
108 
109 static int idxd_dma_alloc_chan_resources(struct dma_chan *chan)
110 {
111 	struct idxd_wq *wq = to_idxd_wq(chan);
112 	struct device *dev = &wq->idxd->pdev->dev;
113 
114 	idxd_wq_get(wq);
115 	dev_dbg(dev, "%s: client_count: %d\n", __func__,
116 		idxd_wq_refcount(wq));
117 	return 0;
118 }
119 
120 static void idxd_dma_free_chan_resources(struct dma_chan *chan)
121 {
122 	struct idxd_wq *wq = to_idxd_wq(chan);
123 	struct device *dev = &wq->idxd->pdev->dev;
124 
125 	idxd_wq_put(wq);
126 	dev_dbg(dev, "%s: client_count: %d\n", __func__,
127 		idxd_wq_refcount(wq));
128 }
129 
130 static enum dma_status idxd_dma_tx_status(struct dma_chan *dma_chan,
131 					  dma_cookie_t cookie,
132 					  struct dma_tx_state *txstate)
133 {
134 	return DMA_OUT_OF_ORDER;
135 }
136 
137 /*
138  * issue_pending() does not need to do anything since tx_submit() does the job
139  * already.
140  */
141 static void idxd_dma_issue_pending(struct dma_chan *dma_chan)
142 {
143 }
144 
145 static dma_cookie_t idxd_dma_tx_submit(struct dma_async_tx_descriptor *tx)
146 {
147 	struct dma_chan *c = tx->chan;
148 	struct idxd_wq *wq = to_idxd_wq(c);
149 	dma_cookie_t cookie;
150 	int rc;
151 	struct idxd_desc *desc = container_of(tx, struct idxd_desc, txd);
152 
153 	cookie = dma_cookie_assign(tx);
154 
155 	rc = idxd_submit_desc(wq, desc);
156 	if (rc < 0)
157 		return rc;
158 
159 	return cookie;
160 }
161 
162 static void idxd_dma_release(struct dma_device *device)
163 {
164 	struct idxd_dma_dev *idxd_dma = container_of(device, struct idxd_dma_dev, dma);
165 
166 	kfree(idxd_dma);
167 }
168 
169 int idxd_register_dma_device(struct idxd_device *idxd)
170 {
171 	struct idxd_dma_dev *idxd_dma;
172 	struct dma_device *dma;
173 	struct device *dev = &idxd->pdev->dev;
174 	int rc;
175 
176 	idxd_dma = kzalloc_node(sizeof(*idxd_dma), GFP_KERNEL, dev_to_node(dev));
177 	if (!idxd_dma)
178 		return -ENOMEM;
179 
180 	dma = &idxd_dma->dma;
181 	INIT_LIST_HEAD(&dma->channels);
182 	dma->dev = dev;
183 
184 	dma_cap_set(DMA_PRIVATE, dma->cap_mask);
185 	dma_cap_set(DMA_COMPLETION_NO_ORDER, dma->cap_mask);
186 	dma->device_release = idxd_dma_release;
187 
188 	if (idxd->hw.opcap.bits[0] & IDXD_OPCAP_MEMMOVE) {
189 		dma_cap_set(DMA_MEMCPY, dma->cap_mask);
190 		dma->device_prep_dma_memcpy = idxd_dma_submit_memcpy;
191 	}
192 
193 	dma->device_tx_status = idxd_dma_tx_status;
194 	dma->device_issue_pending = idxd_dma_issue_pending;
195 	dma->device_alloc_chan_resources = idxd_dma_alloc_chan_resources;
196 	dma->device_free_chan_resources = idxd_dma_free_chan_resources;
197 
198 	rc = dma_async_device_register(dma);
199 	if (rc < 0) {
200 		kfree(idxd_dma);
201 		return rc;
202 	}
203 
204 	idxd_dma->idxd = idxd;
205 	/*
206 	 * This pointer is protected by the refs taken by the dma_chan. It will remain valid
207 	 * as long as there are outstanding channels.
208 	 */
209 	idxd->idxd_dma = idxd_dma;
210 	return 0;
211 }
212 
213 void idxd_unregister_dma_device(struct idxd_device *idxd)
214 {
215 	dma_async_device_unregister(&idxd->idxd_dma->dma);
216 }
217 
218 int idxd_register_dma_channel(struct idxd_wq *wq)
219 {
220 	struct idxd_device *idxd = wq->idxd;
221 	struct dma_device *dma = &idxd->idxd_dma->dma;
222 	struct device *dev = &idxd->pdev->dev;
223 	struct idxd_dma_chan *idxd_chan;
224 	struct dma_chan *chan;
225 	int rc, i;
226 
227 	idxd_chan = kzalloc_node(sizeof(*idxd_chan), GFP_KERNEL, dev_to_node(dev));
228 	if (!idxd_chan)
229 		return -ENOMEM;
230 
231 	chan = &idxd_chan->chan;
232 	chan->device = dma;
233 	list_add_tail(&chan->device_node, &dma->channels);
234 
235 	for (i = 0; i < wq->num_descs; i++) {
236 		struct idxd_desc *desc = wq->descs[i];
237 
238 		dma_async_tx_descriptor_init(&desc->txd, chan);
239 		desc->txd.tx_submit = idxd_dma_tx_submit;
240 	}
241 
242 	rc = dma_async_device_channel_register(dma, chan);
243 	if (rc < 0) {
244 		kfree(idxd_chan);
245 		return rc;
246 	}
247 
248 	wq->idxd_chan = idxd_chan;
249 	idxd_chan->wq = wq;
250 	get_device(wq_confdev(wq));
251 
252 	return 0;
253 }
254 
255 void idxd_unregister_dma_channel(struct idxd_wq *wq)
256 {
257 	struct idxd_dma_chan *idxd_chan = wq->idxd_chan;
258 	struct dma_chan *chan = &idxd_chan->chan;
259 	struct idxd_dma_dev *idxd_dma = wq->idxd->idxd_dma;
260 
261 	dma_async_device_channel_unregister(&idxd_dma->dma, chan);
262 	list_del(&chan->device_node);
263 	kfree(wq->idxd_chan);
264 	wq->idxd_chan = NULL;
265 	put_device(wq_confdev(wq));
266 }
267 
268 static int idxd_dmaengine_drv_probe(struct idxd_dev *idxd_dev)
269 {
270 	struct device *dev = &idxd_dev->conf_dev;
271 	struct idxd_wq *wq = idxd_dev_to_wq(idxd_dev);
272 	struct idxd_device *idxd = wq->idxd;
273 	int rc;
274 
275 	if (idxd->state != IDXD_DEV_ENABLED)
276 		return -ENXIO;
277 
278 	mutex_lock(&wq->wq_lock);
279 	wq->type = IDXD_WQT_KERNEL;
280 	rc = __drv_enable_wq(wq);
281 	if (rc < 0) {
282 		dev_dbg(dev, "Enable wq %d failed: %d\n", wq->id, rc);
283 		rc = -ENXIO;
284 		goto err;
285 	}
286 
287 	rc = idxd_wq_alloc_resources(wq);
288 	if (rc < 0) {
289 		idxd->cmd_status = IDXD_SCMD_WQ_RES_ALLOC_ERR;
290 		dev_dbg(dev, "WQ resource alloc failed\n");
291 		goto err_res_alloc;
292 	}
293 
294 	rc = idxd_wq_init_percpu_ref(wq);
295 	if (rc < 0) {
296 		idxd->cmd_status = IDXD_SCMD_PERCPU_ERR;
297 		dev_dbg(dev, "percpu_ref setup failed\n");
298 		goto err_ref;
299 	}
300 
301 	rc = idxd_register_dma_channel(wq);
302 	if (rc < 0) {
303 		idxd->cmd_status = IDXD_SCMD_DMA_CHAN_ERR;
304 		dev_dbg(dev, "Failed to register dma channel\n");
305 		goto err_dma;
306 	}
307 
308 	idxd->cmd_status = 0;
309 	mutex_unlock(&wq->wq_lock);
310 	return 0;
311 
312 err_dma:
313 	idxd_wq_quiesce(wq);
314 	percpu_ref_exit(&wq->wq_active);
315 err_ref:
316 	idxd_wq_free_resources(wq);
317 err_res_alloc:
318 	__drv_disable_wq(wq);
319 err:
320 	wq->type = IDXD_WQT_NONE;
321 	mutex_unlock(&wq->wq_lock);
322 	return rc;
323 }
324 
325 static void idxd_dmaengine_drv_remove(struct idxd_dev *idxd_dev)
326 {
327 	struct idxd_wq *wq = idxd_dev_to_wq(idxd_dev);
328 
329 	mutex_lock(&wq->wq_lock);
330 	idxd_wq_quiesce(wq);
331 	idxd_unregister_dma_channel(wq);
332 	idxd_wq_free_resources(wq);
333 	__drv_disable_wq(wq);
334 	percpu_ref_exit(&wq->wq_active);
335 	mutex_unlock(&wq->wq_lock);
336 }
337 
338 static enum idxd_dev_type dev_types[] = {
339 	IDXD_DEV_WQ,
340 	IDXD_DEV_NONE,
341 };
342 
343 struct idxd_device_driver idxd_dmaengine_drv = {
344 	.probe = idxd_dmaengine_drv_probe,
345 	.remove = idxd_dmaengine_drv_remove,
346 	.name = "dmaengine",
347 	.type = dev_types,
348 };
349 EXPORT_SYMBOL_GPL(idxd_dmaengine_drv);
350