xref: /openbmc/linux/drivers/fpga/stratix10-soc.c (revision 3a83e4e6)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * FPGA Manager Driver for Intel Stratix10 SoC
4  *
5  *  Copyright (C) 2018 Intel Corporation
6  */
7 #include <linux/completion.h>
8 #include <linux/fpga/fpga-mgr.h>
9 #include <linux/firmware/intel/stratix10-svc-client.h>
10 #include <linux/module.h>
11 #include <linux/of.h>
12 #include <linux/of_platform.h>
13 
14 /*
15  * FPGA programming requires a higher level of privilege (EL3), per the SoC
16  * design.
17  */
18 #define NUM_SVC_BUFS	4
19 #define SVC_BUF_SIZE	SZ_512K
20 
21 /* Indicates buffer is in use if set */
22 #define SVC_BUF_LOCK	0
23 
24 #define S10_BUFFER_TIMEOUT (msecs_to_jiffies(SVC_RECONFIG_BUFFER_TIMEOUT_MS))
25 #define S10_RECONFIG_TIMEOUT (msecs_to_jiffies(SVC_RECONFIG_REQUEST_TIMEOUT_MS))
26 
27 /*
28  * struct s10_svc_buf
29  * buf:  virtual address of buf provided by service layer
30  * lock: locked if buffer is in use
31  */
32 struct s10_svc_buf {
33 	char *buf;
34 	unsigned long lock;
35 };
36 
37 struct s10_priv {
38 	struct stratix10_svc_chan *chan;
39 	struct stratix10_svc_client client;
40 	struct completion status_return_completion;
41 	struct s10_svc_buf svc_bufs[NUM_SVC_BUFS];
42 	unsigned long status;
43 };
44 
45 static int s10_svc_send_msg(struct s10_priv *priv,
46 			    enum stratix10_svc_command_code command,
47 			    void *payload, u32 payload_length)
48 {
49 	struct stratix10_svc_chan *chan = priv->chan;
50 	struct device *dev = priv->client.dev;
51 	struct stratix10_svc_client_msg msg;
52 	int ret;
53 
54 	dev_dbg(dev, "%s cmd=%d payload=%p length=%d\n",
55 		__func__, command, payload, payload_length);
56 
57 	msg.command = command;
58 	msg.payload = payload;
59 	msg.payload_length = payload_length;
60 
61 	ret = stratix10_svc_send(chan, &msg);
62 	dev_dbg(dev, "stratix10_svc_send returned status %d\n", ret);
63 
64 	return ret;
65 }
66 
67 /*
68  * Free buffers allocated from the service layer's pool that are not in use.
69  * Return true when all buffers are freed.
70  */
71 static bool s10_free_buffers(struct fpga_manager *mgr)
72 {
73 	struct s10_priv *priv = mgr->priv;
74 	uint num_free = 0;
75 	uint i;
76 
77 	for (i = 0; i < NUM_SVC_BUFS; i++) {
78 		if (!priv->svc_bufs[i].buf) {
79 			num_free++;
80 			continue;
81 		}
82 
83 		if (!test_and_set_bit_lock(SVC_BUF_LOCK,
84 					   &priv->svc_bufs[i].lock)) {
85 			stratix10_svc_free_memory(priv->chan,
86 						  priv->svc_bufs[i].buf);
87 			priv->svc_bufs[i].buf = NULL;
88 			num_free++;
89 		}
90 	}
91 
92 	return num_free == NUM_SVC_BUFS;
93 }
94 
95 /*
96  * Returns count of how many buffers are not in use.
97  */
98 static uint s10_free_buffer_count(struct fpga_manager *mgr)
99 {
100 	struct s10_priv *priv = mgr->priv;
101 	uint num_free = 0;
102 	uint i;
103 
104 	for (i = 0; i < NUM_SVC_BUFS; i++)
105 		if (!priv->svc_bufs[i].buf)
106 			num_free++;
107 
108 	return num_free;
109 }
110 
111 /*
112  * s10_unlock_bufs
113  * Given the returned buffer address, match that address to our buffer struct
114  * and unlock that buffer.  This marks it as available to be refilled and sent
115  * (or freed).
116  * priv: private data
117  * kaddr: kernel address of buffer that was returned from service layer
118  */
119 static void s10_unlock_bufs(struct s10_priv *priv, void *kaddr)
120 {
121 	uint i;
122 
123 	if (!kaddr)
124 		return;
125 
126 	for (i = 0; i < NUM_SVC_BUFS; i++)
127 		if (priv->svc_bufs[i].buf == kaddr) {
128 			clear_bit_unlock(SVC_BUF_LOCK,
129 					 &priv->svc_bufs[i].lock);
130 			return;
131 		}
132 
133 	WARN(1, "Unknown buffer returned from service layer %p\n", kaddr);
134 }
135 
136 /*
137  * s10_receive_callback - callback for service layer to use to provide client
138  * (this driver) messages received through the mailbox.
139  * client: service layer client struct
140  * data: message from service layer
141  */
142 static void s10_receive_callback(struct stratix10_svc_client *client,
143 				 struct stratix10_svc_cb_data *data)
144 {
145 	struct s10_priv *priv = client->priv;
146 	u32 status;
147 	int i;
148 
149 	WARN_ONCE(!data, "%s: stratix10_svc_rc_data = NULL", __func__);
150 
151 	status = data->status;
152 
153 	/*
154 	 * Here we set status bits as we receive them.  Elsewhere, we always use
155 	 * test_and_clear_bit() to check status in priv->status
156 	 */
157 	for (i = 0; i <= SVC_STATUS_ERROR; i++)
158 		if (status & (1 << i))
159 			set_bit(i, &priv->status);
160 
161 	if (status & BIT(SVC_STATUS_BUFFER_DONE)) {
162 		s10_unlock_bufs(priv, data->kaddr1);
163 		s10_unlock_bufs(priv, data->kaddr2);
164 		s10_unlock_bufs(priv, data->kaddr3);
165 	}
166 
167 	complete(&priv->status_return_completion);
168 }
169 
170 /*
171  * s10_ops_write_init - prepare for FPGA reconfiguration by requesting
172  * partial reconfig and allocating buffers from the service layer.
173  */
174 static int s10_ops_write_init(struct fpga_manager *mgr,
175 			      struct fpga_image_info *info,
176 			      const char *buf, size_t count)
177 {
178 	struct s10_priv *priv = mgr->priv;
179 	struct device *dev = priv->client.dev;
180 	struct stratix10_svc_command_config_type ctype;
181 	char *kbuf;
182 	uint i;
183 	int ret;
184 
185 	ctype.flags = 0;
186 	if (info->flags & FPGA_MGR_PARTIAL_RECONFIG) {
187 		dev_dbg(dev, "Requesting partial reconfiguration.\n");
188 		ctype.flags |= BIT(COMMAND_RECONFIG_FLAG_PARTIAL);
189 	} else {
190 		dev_dbg(dev, "Requesting full reconfiguration.\n");
191 	}
192 
193 	reinit_completion(&priv->status_return_completion);
194 	ret = s10_svc_send_msg(priv, COMMAND_RECONFIG,
195 			       &ctype, sizeof(ctype));
196 	if (ret < 0)
197 		goto init_done;
198 
199 	ret = wait_for_completion_interruptible_timeout(
200 		&priv->status_return_completion, S10_RECONFIG_TIMEOUT);
201 	if (!ret) {
202 		dev_err(dev, "timeout waiting for RECONFIG_REQUEST\n");
203 		ret = -ETIMEDOUT;
204 		goto init_done;
205 	}
206 	if (ret < 0) {
207 		dev_err(dev, "error (%d) waiting for RECONFIG_REQUEST\n", ret);
208 		goto init_done;
209 	}
210 
211 	ret = 0;
212 	if (!test_and_clear_bit(SVC_STATUS_OK, &priv->status)) {
213 		ret = -ETIMEDOUT;
214 		goto init_done;
215 	}
216 
217 	/* Allocate buffers from the service layer's pool. */
218 	for (i = 0; i < NUM_SVC_BUFS; i++) {
219 		kbuf = stratix10_svc_allocate_memory(priv->chan, SVC_BUF_SIZE);
220 		if (!kbuf) {
221 			s10_free_buffers(mgr);
222 			ret = -ENOMEM;
223 			goto init_done;
224 		}
225 
226 		priv->svc_bufs[i].buf = kbuf;
227 		priv->svc_bufs[i].lock = 0;
228 	}
229 
230 init_done:
231 	stratix10_svc_done(priv->chan);
232 	return ret;
233 }
234 
235 /*
236  * s10_send_buf - send a buffer to the service layer queue
237  * mgr: fpga manager struct
238  * buf: fpga image buffer
239  * count: size of buf in bytes
240  * Returns # of bytes transferred or -ENOBUFS if the all the buffers are in use
241  * or if the service queue is full. Never returns 0.
242  */
243 static int s10_send_buf(struct fpga_manager *mgr, const char *buf, size_t count)
244 {
245 	struct s10_priv *priv = mgr->priv;
246 	struct device *dev = priv->client.dev;
247 	void *svc_buf;
248 	size_t xfer_sz;
249 	int ret;
250 	uint i;
251 
252 	/* get/lock a buffer that that's not being used */
253 	for (i = 0; i < NUM_SVC_BUFS; i++)
254 		if (!test_and_set_bit_lock(SVC_BUF_LOCK,
255 					   &priv->svc_bufs[i].lock))
256 			break;
257 
258 	if (i == NUM_SVC_BUFS)
259 		return -ENOBUFS;
260 
261 	xfer_sz = count < SVC_BUF_SIZE ? count : SVC_BUF_SIZE;
262 
263 	svc_buf = priv->svc_bufs[i].buf;
264 	memcpy(svc_buf, buf, xfer_sz);
265 	ret = s10_svc_send_msg(priv, COMMAND_RECONFIG_DATA_SUBMIT,
266 			       svc_buf, xfer_sz);
267 	if (ret < 0) {
268 		dev_err(dev,
269 			"Error while sending data to service layer (%d)", ret);
270 		clear_bit_unlock(SVC_BUF_LOCK, &priv->svc_bufs[i].lock);
271 		return ret;
272 	}
273 
274 	return xfer_sz;
275 }
276 
277 /*
278  * Send a FPGA image to privileged layers to write to the FPGA.  When done
279  * sending, free all service layer buffers we allocated in write_init.
280  */
281 static int s10_ops_write(struct fpga_manager *mgr, const char *buf,
282 			 size_t count)
283 {
284 	struct s10_priv *priv = mgr->priv;
285 	struct device *dev = priv->client.dev;
286 	long wait_status;
287 	int sent = 0;
288 	int ret = 0;
289 
290 	/*
291 	 * Loop waiting for buffers to be returned.  When a buffer is returned,
292 	 * reuse it to send more data or free if if all data has been sent.
293 	 */
294 	while (count > 0 || s10_free_buffer_count(mgr) != NUM_SVC_BUFS) {
295 		reinit_completion(&priv->status_return_completion);
296 
297 		if (count > 0) {
298 			sent = s10_send_buf(mgr, buf, count);
299 			if (sent < 0)
300 				continue;
301 
302 			count -= sent;
303 			buf += sent;
304 		} else {
305 			if (s10_free_buffers(mgr))
306 				return 0;
307 
308 			ret = s10_svc_send_msg(
309 				priv, COMMAND_RECONFIG_DATA_CLAIM,
310 				NULL, 0);
311 			if (ret < 0)
312 				break;
313 		}
314 
315 		/*
316 		 * If callback hasn't already happened, wait for buffers to be
317 		 * returned from service layer
318 		 */
319 		wait_status = 1; /* not timed out */
320 		if (!priv->status)
321 			wait_status = wait_for_completion_interruptible_timeout(
322 				&priv->status_return_completion,
323 				S10_BUFFER_TIMEOUT);
324 
325 		if (test_and_clear_bit(SVC_STATUS_BUFFER_DONE, &priv->status) ||
326 		    test_and_clear_bit(SVC_STATUS_BUFFER_SUBMITTED,
327 				       &priv->status)) {
328 			ret = 0;
329 			continue;
330 		}
331 
332 		if (test_and_clear_bit(SVC_STATUS_ERROR, &priv->status)) {
333 			dev_err(dev, "ERROR - giving up - SVC_STATUS_ERROR\n");
334 			ret = -EFAULT;
335 			break;
336 		}
337 
338 		if (!wait_status) {
339 			dev_err(dev, "timeout waiting for svc layer buffers\n");
340 			ret = -ETIMEDOUT;
341 			break;
342 		}
343 		if (wait_status < 0) {
344 			ret = wait_status;
345 			dev_err(dev,
346 				"error (%d) waiting for svc layer buffers\n",
347 				ret);
348 			break;
349 		}
350 	}
351 
352 	if (!s10_free_buffers(mgr))
353 		dev_err(dev, "%s not all buffers were freed\n", __func__);
354 
355 	return ret;
356 }
357 
358 static int s10_ops_write_complete(struct fpga_manager *mgr,
359 				  struct fpga_image_info *info)
360 {
361 	struct s10_priv *priv = mgr->priv;
362 	struct device *dev = priv->client.dev;
363 	unsigned long timeout;
364 	int ret;
365 
366 	timeout = usecs_to_jiffies(info->config_complete_timeout_us);
367 
368 	do {
369 		reinit_completion(&priv->status_return_completion);
370 
371 		ret = s10_svc_send_msg(priv, COMMAND_RECONFIG_STATUS, NULL, 0);
372 		if (ret < 0)
373 			break;
374 
375 		ret = wait_for_completion_interruptible_timeout(
376 			&priv->status_return_completion, timeout);
377 		if (!ret) {
378 			dev_err(dev,
379 				"timeout waiting for RECONFIG_COMPLETED\n");
380 			ret = -ETIMEDOUT;
381 			break;
382 		}
383 		if (ret < 0) {
384 			dev_err(dev,
385 				"error (%d) waiting for RECONFIG_COMPLETED\n",
386 				ret);
387 			break;
388 		}
389 		/* Not error or timeout, so ret is # of jiffies until timeout */
390 		timeout = ret;
391 		ret = 0;
392 
393 		if (test_and_clear_bit(SVC_STATUS_COMPLETED, &priv->status))
394 			break;
395 
396 		if (test_and_clear_bit(SVC_STATUS_ERROR, &priv->status)) {
397 			dev_err(dev, "ERROR - giving up - SVC_STATUS_ERROR\n");
398 			ret = -EFAULT;
399 			break;
400 		}
401 	} while (1);
402 
403 	stratix10_svc_done(priv->chan);
404 
405 	return ret;
406 }
407 
408 static enum fpga_mgr_states s10_ops_state(struct fpga_manager *mgr)
409 {
410 	return FPGA_MGR_STATE_UNKNOWN;
411 }
412 
413 static const struct fpga_manager_ops s10_ops = {
414 	.state = s10_ops_state,
415 	.write_init = s10_ops_write_init,
416 	.write = s10_ops_write,
417 	.write_complete = s10_ops_write_complete,
418 };
419 
420 static int s10_probe(struct platform_device *pdev)
421 {
422 	struct device *dev = &pdev->dev;
423 	struct s10_priv *priv;
424 	struct fpga_manager *mgr;
425 	int ret;
426 
427 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
428 	if (!priv)
429 		return -ENOMEM;
430 
431 	priv->client.dev = dev;
432 	priv->client.receive_cb = s10_receive_callback;
433 	priv->client.priv = priv;
434 
435 	priv->chan = stratix10_svc_request_channel_byname(&priv->client,
436 							  SVC_CLIENT_FPGA);
437 	if (IS_ERR(priv->chan)) {
438 		dev_err(dev, "couldn't get service channel (%s)\n",
439 			SVC_CLIENT_FPGA);
440 		return PTR_ERR(priv->chan);
441 	}
442 
443 	init_completion(&priv->status_return_completion);
444 
445 	mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
446 			      &s10_ops, priv);
447 	if (!mgr) {
448 		dev_err(dev, "unable to create FPGA manager\n");
449 		ret = -ENOMEM;
450 		goto probe_err;
451 	}
452 
453 	ret = fpga_mgr_register(mgr);
454 	if (ret) {
455 		dev_err(dev, "unable to register FPGA manager\n");
456 		fpga_mgr_free(mgr);
457 		goto probe_err;
458 	}
459 
460 	platform_set_drvdata(pdev, mgr);
461 	return ret;
462 
463 probe_err:
464 	stratix10_svc_free_channel(priv->chan);
465 	return ret;
466 }
467 
468 static int s10_remove(struct platform_device *pdev)
469 {
470 	struct fpga_manager *mgr = platform_get_drvdata(pdev);
471 	struct s10_priv *priv = mgr->priv;
472 
473 	fpga_mgr_unregister(mgr);
474 	stratix10_svc_free_channel(priv->chan);
475 
476 	return 0;
477 }
478 
479 static const struct of_device_id s10_of_match[] = {
480 	{.compatible = "intel,stratix10-soc-fpga-mgr"},
481 	{.compatible = "intel,agilex-soc-fpga-mgr"},
482 	{},
483 };
484 
485 MODULE_DEVICE_TABLE(of, s10_of_match);
486 
487 static struct platform_driver s10_driver = {
488 	.probe = s10_probe,
489 	.remove = s10_remove,
490 	.driver = {
491 		.name	= "Stratix10 SoC FPGA manager",
492 		.of_match_table = of_match_ptr(s10_of_match),
493 	},
494 };
495 
496 static int __init s10_init(void)
497 {
498 	struct device_node *fw_np;
499 	struct device_node *np;
500 	int ret;
501 
502 	fw_np = of_find_node_by_name(NULL, "svc");
503 	if (!fw_np)
504 		return -ENODEV;
505 
506 	of_node_get(fw_np);
507 	np = of_find_matching_node(fw_np, s10_of_match);
508 	if (!np) {
509 		of_node_put(fw_np);
510 		return -ENODEV;
511 	}
512 
513 	of_node_put(np);
514 	ret = of_platform_populate(fw_np, s10_of_match, NULL, NULL);
515 	of_node_put(fw_np);
516 	if (ret)
517 		return ret;
518 
519 	return platform_driver_register(&s10_driver);
520 }
521 
522 static void __exit s10_exit(void)
523 {
524 	return platform_driver_unregister(&s10_driver);
525 }
526 
527 module_init(s10_init);
528 module_exit(s10_exit);
529 
530 MODULE_AUTHOR("Alan Tull <atull@kernel.org>");
531 MODULE_DESCRIPTION("Intel Stratix 10 SOC FPGA Manager");
532 MODULE_LICENSE("GPL v2");
533