xref: /openbmc/linux/drivers/fpga/stratix10-soc.c (revision b830f94f)
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_RECONFIG_ERROR; i++)
158 		if (status & (1 << i))
159 			set_bit(i, &priv->status);
160 
161 	if (status & BIT(SVC_STATUS_RECONFIG_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_RECONFIG_REQUEST_OK,
213 				&priv->status)) {
214 		ret = -ETIMEDOUT;
215 		goto init_done;
216 	}
217 
218 	/* Allocate buffers from the service layer's pool. */
219 	for (i = 0; i < NUM_SVC_BUFS; i++) {
220 		kbuf = stratix10_svc_allocate_memory(priv->chan, SVC_BUF_SIZE);
221 		if (!kbuf) {
222 			s10_free_buffers(mgr);
223 			ret = -ENOMEM;
224 			goto init_done;
225 		}
226 
227 		priv->svc_bufs[i].buf = kbuf;
228 		priv->svc_bufs[i].lock = 0;
229 	}
230 
231 init_done:
232 	stratix10_svc_done(priv->chan);
233 	return ret;
234 }
235 
236 /*
237  * s10_send_buf - send a buffer to the service layer queue
238  * mgr: fpga manager struct
239  * buf: fpga image buffer
240  * count: size of buf in bytes
241  * Returns # of bytes transferred or -ENOBUFS if the all the buffers are in use
242  * or if the service queue is full. Never returns 0.
243  */
244 static int s10_send_buf(struct fpga_manager *mgr, const char *buf, size_t count)
245 {
246 	struct s10_priv *priv = mgr->priv;
247 	struct device *dev = priv->client.dev;
248 	void *svc_buf;
249 	size_t xfer_sz;
250 	int ret;
251 	uint i;
252 
253 	/* get/lock a buffer that that's not being used */
254 	for (i = 0; i < NUM_SVC_BUFS; i++)
255 		if (!test_and_set_bit_lock(SVC_BUF_LOCK,
256 					   &priv->svc_bufs[i].lock))
257 			break;
258 
259 	if (i == NUM_SVC_BUFS)
260 		return -ENOBUFS;
261 
262 	xfer_sz = count < SVC_BUF_SIZE ? count : SVC_BUF_SIZE;
263 
264 	svc_buf = priv->svc_bufs[i].buf;
265 	memcpy(svc_buf, buf, xfer_sz);
266 	ret = s10_svc_send_msg(priv, COMMAND_RECONFIG_DATA_SUBMIT,
267 			       svc_buf, xfer_sz);
268 	if (ret < 0) {
269 		dev_err(dev,
270 			"Error while sending data to service layer (%d)", ret);
271 		clear_bit_unlock(SVC_BUF_LOCK, &priv->svc_bufs[i].lock);
272 		return ret;
273 	}
274 
275 	return xfer_sz;
276 }
277 
278 /*
279  * Send a FPGA image to privileged layers to write to the FPGA.  When done
280  * sending, free all service layer buffers we allocated in write_init.
281  */
282 static int s10_ops_write(struct fpga_manager *mgr, const char *buf,
283 			 size_t count)
284 {
285 	struct s10_priv *priv = mgr->priv;
286 	struct device *dev = priv->client.dev;
287 	long wait_status;
288 	int sent = 0;
289 	int ret = 0;
290 
291 	/*
292 	 * Loop waiting for buffers to be returned.  When a buffer is returned,
293 	 * reuse it to send more data or free if if all data has been sent.
294 	 */
295 	while (count > 0 || s10_free_buffer_count(mgr) != NUM_SVC_BUFS) {
296 		reinit_completion(&priv->status_return_completion);
297 
298 		if (count > 0) {
299 			sent = s10_send_buf(mgr, buf, count);
300 			if (sent < 0)
301 				continue;
302 
303 			count -= sent;
304 			buf += sent;
305 		} else {
306 			if (s10_free_buffers(mgr))
307 				return 0;
308 
309 			ret = s10_svc_send_msg(
310 				priv, COMMAND_RECONFIG_DATA_CLAIM,
311 				NULL, 0);
312 			if (ret < 0)
313 				break;
314 		}
315 
316 		/*
317 		 * If callback hasn't already happened, wait for buffers to be
318 		 * returned from service layer
319 		 */
320 		wait_status = 1; /* not timed out */
321 		if (!priv->status)
322 			wait_status = wait_for_completion_interruptible_timeout(
323 				&priv->status_return_completion,
324 				S10_BUFFER_TIMEOUT);
325 
326 		if (test_and_clear_bit(SVC_STATUS_RECONFIG_BUFFER_DONE,
327 				       &priv->status) ||
328 		    test_and_clear_bit(SVC_STATUS_RECONFIG_BUFFER_SUBMITTED,
329 				       &priv->status)) {
330 			ret = 0;
331 			continue;
332 		}
333 
334 		if (test_and_clear_bit(SVC_STATUS_RECONFIG_ERROR,
335 				       &priv->status)) {
336 			dev_err(dev, "ERROR - giving up - SVC_STATUS_RECONFIG_ERROR\n");
337 			ret = -EFAULT;
338 			break;
339 		}
340 
341 		if (!wait_status) {
342 			dev_err(dev, "timeout waiting for svc layer buffers\n");
343 			ret = -ETIMEDOUT;
344 			break;
345 		}
346 		if (wait_status < 0) {
347 			ret = wait_status;
348 			dev_err(dev,
349 				"error (%d) waiting for svc layer buffers\n",
350 				ret);
351 			break;
352 		}
353 	}
354 
355 	if (!s10_free_buffers(mgr))
356 		dev_err(dev, "%s not all buffers were freed\n", __func__);
357 
358 	return ret;
359 }
360 
361 static int s10_ops_write_complete(struct fpga_manager *mgr,
362 				  struct fpga_image_info *info)
363 {
364 	struct s10_priv *priv = mgr->priv;
365 	struct device *dev = priv->client.dev;
366 	unsigned long timeout;
367 	int ret;
368 
369 	timeout = usecs_to_jiffies(info->config_complete_timeout_us);
370 
371 	do {
372 		reinit_completion(&priv->status_return_completion);
373 
374 		ret = s10_svc_send_msg(priv, COMMAND_RECONFIG_STATUS, NULL, 0);
375 		if (ret < 0)
376 			break;
377 
378 		ret = wait_for_completion_interruptible_timeout(
379 			&priv->status_return_completion, timeout);
380 		if (!ret) {
381 			dev_err(dev,
382 				"timeout waiting for RECONFIG_COMPLETED\n");
383 			ret = -ETIMEDOUT;
384 			break;
385 		}
386 		if (ret < 0) {
387 			dev_err(dev,
388 				"error (%d) waiting for RECONFIG_COMPLETED\n",
389 				ret);
390 			break;
391 		}
392 		/* Not error or timeout, so ret is # of jiffies until timeout */
393 		timeout = ret;
394 		ret = 0;
395 
396 		if (test_and_clear_bit(SVC_STATUS_RECONFIG_COMPLETED,
397 				       &priv->status))
398 			break;
399 
400 		if (test_and_clear_bit(SVC_STATUS_RECONFIG_ERROR,
401 				       &priv->status)) {
402 			dev_err(dev, "ERROR - giving up - SVC_STATUS_RECONFIG_ERROR\n");
403 			ret = -EFAULT;
404 			break;
405 		}
406 	} while (1);
407 
408 	stratix10_svc_done(priv->chan);
409 
410 	return ret;
411 }
412 
413 static enum fpga_mgr_states s10_ops_state(struct fpga_manager *mgr)
414 {
415 	return FPGA_MGR_STATE_UNKNOWN;
416 }
417 
418 static const struct fpga_manager_ops s10_ops = {
419 	.state = s10_ops_state,
420 	.write_init = s10_ops_write_init,
421 	.write = s10_ops_write,
422 	.write_complete = s10_ops_write_complete,
423 };
424 
425 static int s10_probe(struct platform_device *pdev)
426 {
427 	struct device *dev = &pdev->dev;
428 	struct s10_priv *priv;
429 	struct fpga_manager *mgr;
430 	int ret;
431 
432 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
433 	if (!priv)
434 		return -ENOMEM;
435 
436 	priv->client.dev = dev;
437 	priv->client.receive_cb = s10_receive_callback;
438 	priv->client.priv = priv;
439 
440 	priv->chan = stratix10_svc_request_channel_byname(&priv->client,
441 							  SVC_CLIENT_FPGA);
442 	if (IS_ERR(priv->chan)) {
443 		dev_err(dev, "couldn't get service channel (%s)\n",
444 			SVC_CLIENT_FPGA);
445 		return PTR_ERR(priv->chan);
446 	}
447 
448 	init_completion(&priv->status_return_completion);
449 
450 	mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
451 			      &s10_ops, priv);
452 	if (!mgr) {
453 		dev_err(dev, "unable to create FPGA manager\n");
454 		ret = -ENOMEM;
455 		goto probe_err;
456 	}
457 
458 	ret = fpga_mgr_register(mgr);
459 	if (ret) {
460 		dev_err(dev, "unable to register FPGA manager\n");
461 		fpga_mgr_free(mgr);
462 		goto probe_err;
463 	}
464 
465 	platform_set_drvdata(pdev, mgr);
466 	return ret;
467 
468 probe_err:
469 	stratix10_svc_free_channel(priv->chan);
470 	return ret;
471 }
472 
473 static int s10_remove(struct platform_device *pdev)
474 {
475 	struct fpga_manager *mgr = platform_get_drvdata(pdev);
476 	struct s10_priv *priv = mgr->priv;
477 
478 	fpga_mgr_unregister(mgr);
479 	stratix10_svc_free_channel(priv->chan);
480 
481 	return 0;
482 }
483 
484 static const struct of_device_id s10_of_match[] = {
485 	{ .compatible = "intel,stratix10-soc-fpga-mgr", },
486 	{},
487 };
488 
489 MODULE_DEVICE_TABLE(of, s10_of_match);
490 
491 static struct platform_driver s10_driver = {
492 	.probe = s10_probe,
493 	.remove = s10_remove,
494 	.driver = {
495 		.name	= "Stratix10 SoC FPGA manager",
496 		.of_match_table = of_match_ptr(s10_of_match),
497 	},
498 };
499 
500 static int __init s10_init(void)
501 {
502 	struct device_node *fw_np;
503 	struct device_node *np;
504 	int ret;
505 
506 	fw_np = of_find_node_by_name(NULL, "svc");
507 	if (!fw_np)
508 		return -ENODEV;
509 
510 	of_node_get(fw_np);
511 	np = of_find_matching_node(fw_np, s10_of_match);
512 	if (!np) {
513 		of_node_put(fw_np);
514 		return -ENODEV;
515 	}
516 
517 	of_node_put(np);
518 	ret = of_platform_populate(fw_np, s10_of_match, NULL, NULL);
519 	of_node_put(fw_np);
520 	if (ret)
521 		return ret;
522 
523 	return platform_driver_register(&s10_driver);
524 }
525 
526 static void __exit s10_exit(void)
527 {
528 	return platform_driver_unregister(&s10_driver);
529 }
530 
531 module_init(s10_init);
532 module_exit(s10_exit);
533 
534 MODULE_AUTHOR("Alan Tull <atull@kernel.org>");
535 MODULE_DESCRIPTION("Intel Stratix 10 SOC FPGA Manager");
536 MODULE_LICENSE("GPL v2");
537