xref: /openbmc/linux/drivers/dma/idxd/dma.c (revision 2cf1c348)
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 set_completion_address(struct idxd_desc *desc,
67 					  u64 *compl_addr)
68 {
69 		*compl_addr = desc->compl_dma;
70 }
71 
72 static inline void idxd_prep_desc_common(struct idxd_wq *wq,
73 					 struct dsa_hw_desc *hw, char opcode,
74 					 u64 addr_f1, u64 addr_f2, u64 len,
75 					 u64 compl, u32 flags)
76 {
77 	hw->flags = flags;
78 	hw->opcode = opcode;
79 	hw->src_addr = addr_f1;
80 	hw->dst_addr = addr_f2;
81 	hw->xfer_size = len;
82 	/*
83 	 * For dedicated WQ, this field is ignored and HW will use the WQCFG.priv
84 	 * field instead. This field should be set to 1 for kernel descriptors.
85 	 */
86 	hw->priv = 1;
87 	hw->completion_addr = compl;
88 }
89 
90 static struct dma_async_tx_descriptor *
91 idxd_dma_submit_memcpy(struct dma_chan *c, dma_addr_t dma_dest,
92 		       dma_addr_t dma_src, size_t len, unsigned long flags)
93 {
94 	struct idxd_wq *wq = to_idxd_wq(c);
95 	u32 desc_flags;
96 	struct idxd_device *idxd = wq->idxd;
97 	struct idxd_desc *desc;
98 
99 	if (wq->state != IDXD_WQ_ENABLED)
100 		return NULL;
101 
102 	if (len > idxd->max_xfer_bytes)
103 		return NULL;
104 
105 	op_flag_setup(flags, &desc_flags);
106 	desc = idxd_alloc_desc(wq, IDXD_OP_BLOCK);
107 	if (IS_ERR(desc))
108 		return NULL;
109 
110 	idxd_prep_desc_common(wq, desc->hw, DSA_OPCODE_MEMMOVE,
111 			      dma_src, dma_dest, len, desc->compl_dma,
112 			      desc_flags);
113 
114 	desc->txd.flags = flags;
115 
116 	return &desc->txd;
117 }
118 
119 static int idxd_dma_alloc_chan_resources(struct dma_chan *chan)
120 {
121 	struct idxd_wq *wq = to_idxd_wq(chan);
122 	struct device *dev = &wq->idxd->pdev->dev;
123 
124 	idxd_wq_get(wq);
125 	dev_dbg(dev, "%s: client_count: %d\n", __func__,
126 		idxd_wq_refcount(wq));
127 	return 0;
128 }
129 
130 static void idxd_dma_free_chan_resources(struct dma_chan *chan)
131 {
132 	struct idxd_wq *wq = to_idxd_wq(chan);
133 	struct device *dev = &wq->idxd->pdev->dev;
134 
135 	idxd_wq_put(wq);
136 	dev_dbg(dev, "%s: client_count: %d\n", __func__,
137 		idxd_wq_refcount(wq));
138 }
139 
140 static enum dma_status idxd_dma_tx_status(struct dma_chan *dma_chan,
141 					  dma_cookie_t cookie,
142 					  struct dma_tx_state *txstate)
143 {
144 	return DMA_OUT_OF_ORDER;
145 }
146 
147 /*
148  * issue_pending() does not need to do anything since tx_submit() does the job
149  * already.
150  */
151 static void idxd_dma_issue_pending(struct dma_chan *dma_chan)
152 {
153 }
154 
155 static dma_cookie_t idxd_dma_tx_submit(struct dma_async_tx_descriptor *tx)
156 {
157 	struct dma_chan *c = tx->chan;
158 	struct idxd_wq *wq = to_idxd_wq(c);
159 	dma_cookie_t cookie;
160 	int rc;
161 	struct idxd_desc *desc = container_of(tx, struct idxd_desc, txd);
162 
163 	cookie = dma_cookie_assign(tx);
164 
165 	rc = idxd_submit_desc(wq, desc);
166 	if (rc < 0) {
167 		idxd_free_desc(wq, desc);
168 		return rc;
169 	}
170 
171 	return cookie;
172 }
173 
174 static void idxd_dma_release(struct dma_device *device)
175 {
176 	struct idxd_dma_dev *idxd_dma = container_of(device, struct idxd_dma_dev, dma);
177 
178 	kfree(idxd_dma);
179 }
180 
181 int idxd_register_dma_device(struct idxd_device *idxd)
182 {
183 	struct idxd_dma_dev *idxd_dma;
184 	struct dma_device *dma;
185 	struct device *dev = &idxd->pdev->dev;
186 	int rc;
187 
188 	idxd_dma = kzalloc_node(sizeof(*idxd_dma), GFP_KERNEL, dev_to_node(dev));
189 	if (!idxd_dma)
190 		return -ENOMEM;
191 
192 	dma = &idxd_dma->dma;
193 	INIT_LIST_HEAD(&dma->channels);
194 	dma->dev = dev;
195 
196 	dma_cap_set(DMA_PRIVATE, dma->cap_mask);
197 	dma_cap_set(DMA_COMPLETION_NO_ORDER, dma->cap_mask);
198 	dma->device_release = idxd_dma_release;
199 
200 	if (idxd->hw.opcap.bits[0] & IDXD_OPCAP_MEMMOVE) {
201 		dma_cap_set(DMA_MEMCPY, dma->cap_mask);
202 		dma->device_prep_dma_memcpy = idxd_dma_submit_memcpy;
203 	}
204 
205 	dma->device_tx_status = idxd_dma_tx_status;
206 	dma->device_issue_pending = idxd_dma_issue_pending;
207 	dma->device_alloc_chan_resources = idxd_dma_alloc_chan_resources;
208 	dma->device_free_chan_resources = idxd_dma_free_chan_resources;
209 
210 	rc = dma_async_device_register(dma);
211 	if (rc < 0) {
212 		kfree(idxd_dma);
213 		return rc;
214 	}
215 
216 	idxd_dma->idxd = idxd;
217 	/*
218 	 * This pointer is protected by the refs taken by the dma_chan. It will remain valid
219 	 * as long as there are outstanding channels.
220 	 */
221 	idxd->idxd_dma = idxd_dma;
222 	return 0;
223 }
224 
225 void idxd_unregister_dma_device(struct idxd_device *idxd)
226 {
227 	dma_async_device_unregister(&idxd->idxd_dma->dma);
228 }
229 
230 int idxd_register_dma_channel(struct idxd_wq *wq)
231 {
232 	struct idxd_device *idxd = wq->idxd;
233 	struct dma_device *dma = &idxd->idxd_dma->dma;
234 	struct device *dev = &idxd->pdev->dev;
235 	struct idxd_dma_chan *idxd_chan;
236 	struct dma_chan *chan;
237 	int rc, i;
238 
239 	idxd_chan = kzalloc_node(sizeof(*idxd_chan), GFP_KERNEL, dev_to_node(dev));
240 	if (!idxd_chan)
241 		return -ENOMEM;
242 
243 	chan = &idxd_chan->chan;
244 	chan->device = dma;
245 	list_add_tail(&chan->device_node, &dma->channels);
246 
247 	for (i = 0; i < wq->num_descs; i++) {
248 		struct idxd_desc *desc = wq->descs[i];
249 
250 		dma_async_tx_descriptor_init(&desc->txd, chan);
251 		desc->txd.tx_submit = idxd_dma_tx_submit;
252 	}
253 
254 	rc = dma_async_device_channel_register(dma, chan);
255 	if (rc < 0) {
256 		kfree(idxd_chan);
257 		return rc;
258 	}
259 
260 	wq->idxd_chan = idxd_chan;
261 	idxd_chan->wq = wq;
262 	get_device(wq_confdev(wq));
263 
264 	return 0;
265 }
266 
267 void idxd_unregister_dma_channel(struct idxd_wq *wq)
268 {
269 	struct idxd_dma_chan *idxd_chan = wq->idxd_chan;
270 	struct dma_chan *chan = &idxd_chan->chan;
271 	struct idxd_dma_dev *idxd_dma = wq->idxd->idxd_dma;
272 
273 	dma_async_device_channel_unregister(&idxd_dma->dma, chan);
274 	list_del(&chan->device_node);
275 	kfree(wq->idxd_chan);
276 	wq->idxd_chan = NULL;
277 	put_device(wq_confdev(wq));
278 }
279 
280 static int idxd_dmaengine_drv_probe(struct idxd_dev *idxd_dev)
281 {
282 	struct device *dev = &idxd_dev->conf_dev;
283 	struct idxd_wq *wq = idxd_dev_to_wq(idxd_dev);
284 	struct idxd_device *idxd = wq->idxd;
285 	int rc;
286 
287 	if (idxd->state != IDXD_DEV_ENABLED)
288 		return -ENXIO;
289 
290 	mutex_lock(&wq->wq_lock);
291 	wq->type = IDXD_WQT_KERNEL;
292 
293 	rc = idxd_wq_request_irq(wq);
294 	if (rc < 0) {
295 		idxd->cmd_status = IDXD_SCMD_WQ_IRQ_ERR;
296 		dev_dbg(dev, "WQ %d irq setup failed: %d\n", wq->id, rc);
297 		goto err_irq;
298 	}
299 
300 	rc = __drv_enable_wq(wq);
301 	if (rc < 0) {
302 		dev_dbg(dev, "Enable wq %d failed: %d\n", wq->id, rc);
303 		rc = -ENXIO;
304 		goto err;
305 	}
306 
307 	rc = idxd_wq_alloc_resources(wq);
308 	if (rc < 0) {
309 		idxd->cmd_status = IDXD_SCMD_WQ_RES_ALLOC_ERR;
310 		dev_dbg(dev, "WQ resource alloc failed\n");
311 		goto err_res_alloc;
312 	}
313 
314 	rc = idxd_wq_init_percpu_ref(wq);
315 	if (rc < 0) {
316 		idxd->cmd_status = IDXD_SCMD_PERCPU_ERR;
317 		dev_dbg(dev, "percpu_ref setup failed\n");
318 		goto err_ref;
319 	}
320 
321 	rc = idxd_register_dma_channel(wq);
322 	if (rc < 0) {
323 		idxd->cmd_status = IDXD_SCMD_DMA_CHAN_ERR;
324 		dev_dbg(dev, "Failed to register dma channel\n");
325 		goto err_dma;
326 	}
327 
328 	idxd->cmd_status = 0;
329 	mutex_unlock(&wq->wq_lock);
330 	return 0;
331 
332 err_dma:
333 	__idxd_wq_quiesce(wq);
334 	percpu_ref_exit(&wq->wq_active);
335 err_ref:
336 	idxd_wq_free_resources(wq);
337 err_res_alloc:
338 	__drv_disable_wq(wq);
339 err:
340 	idxd_wq_free_irq(wq);
341 err_irq:
342 	wq->type = IDXD_WQT_NONE;
343 	mutex_unlock(&wq->wq_lock);
344 	return rc;
345 }
346 
347 static void idxd_dmaengine_drv_remove(struct idxd_dev *idxd_dev)
348 {
349 	struct idxd_wq *wq = idxd_dev_to_wq(idxd_dev);
350 
351 	mutex_lock(&wq->wq_lock);
352 	__idxd_wq_quiesce(wq);
353 	idxd_unregister_dma_channel(wq);
354 	idxd_wq_free_resources(wq);
355 	__drv_disable_wq(wq);
356 	percpu_ref_exit(&wq->wq_active);
357 	idxd_wq_free_irq(wq);
358 	wq->type = IDXD_WQT_NONE;
359 	mutex_unlock(&wq->wq_lock);
360 }
361 
362 static enum idxd_dev_type dev_types[] = {
363 	IDXD_DEV_WQ,
364 	IDXD_DEV_NONE,
365 };
366 
367 struct idxd_device_driver idxd_dmaengine_drv = {
368 	.probe = idxd_dmaengine_drv_probe,
369 	.remove = idxd_dmaengine_drv_remove,
370 	.name = "dmaengine",
371 	.type = dev_types,
372 };
373 EXPORT_SYMBOL_GPL(idxd_dmaengine_drv);
374