xref: /linux/drivers/firmware/microchip/mpfs-auto-update.c (revision 4b660dbd9ee2059850fd30e0df420ca7a38a1856)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Microchip Polarfire SoC "Auto Update" FPGA reprogramming.
4  *
5  * Documentation of this functionality is available in the "PolarFire® FPGA and
6  * PolarFire SoC FPGA Programming" User Guide.
7  *
8  * Copyright (c) 2022-2023 Microchip Corporation. All rights reserved.
9  *
10  * Author: Conor Dooley <conor.dooley@microchip.com>
11  */
12 #include <linux/debugfs.h>
13 #include <linux/firmware.h>
14 #include <linux/math.h>
15 #include <linux/module.h>
16 #include <linux/mtd/mtd.h>
17 #include <linux/platform_device.h>
18 #include <linux/sizes.h>
19 
20 #include <soc/microchip/mpfs.h>
21 
22 #define AUTO_UPDATE_DEFAULT_MBOX_OFFSET		0u
23 #define AUTO_UPDATE_DEFAULT_RESP_OFFSET		0u
24 
25 #define AUTO_UPDATE_FEATURE_CMD_OPCODE		0x05u
26 #define AUTO_UPDATE_FEATURE_CMD_DATA_SIZE	0u
27 #define AUTO_UPDATE_FEATURE_RESP_SIZE		33u
28 #define AUTO_UPDATE_FEATURE_CMD_DATA		NULL
29 #define AUTO_UPDATE_FEATURE_ENABLED		BIT(5)
30 
31 #define AUTO_UPDATE_AUTHENTICATE_CMD_OPCODE	0x22u
32 #define AUTO_UPDATE_AUTHENTICATE_CMD_DATA_SIZE	0u
33 #define AUTO_UPDATE_AUTHENTICATE_RESP_SIZE	1u
34 #define AUTO_UPDATE_AUTHENTICATE_CMD_DATA	NULL
35 
36 #define AUTO_UPDATE_PROGRAM_CMD_OPCODE		0x46u
37 #define AUTO_UPDATE_PROGRAM_CMD_DATA_SIZE	0u
38 #define AUTO_UPDATE_PROGRAM_RESP_SIZE		1u
39 #define AUTO_UPDATE_PROGRAM_CMD_DATA		NULL
40 
41 /*
42  * SPI Flash layout example:
43  * |------------------------------| 0x0000000
44  * | 1 KiB                        |
45  * | SPI "directories"            |
46  * |------------------------------| 0x0000400
47  * | 1 MiB                        |
48  * | Reserved area                |
49  * | Used for bitstream info      |
50  * |------------------------------| 0x0100400
51  * | 20 MiB                       |
52  * | Golden Image                 |
53  * |------------------------------| 0x1500400
54  * | 20 MiB                       |
55  * | Auto Upgrade Image           |
56  * |------------------------------| 0x2900400
57  * | 20 MiB                       |
58  * | Reserved for multi-image IAP |
59  * | Unused for Auto Upgrade      |
60  * |------------------------------| 0x3D00400
61  * | ? B                          |
62  * | Unused                       |
63  * |------------------------------| 0x?
64  */
65 #define AUTO_UPDATE_DIRECTORY_BASE	0u
66 #define AUTO_UPDATE_DIRECTORY_WIDTH	4u
67 #define AUTO_UPDATE_GOLDEN_INDEX	0u
68 #define AUTO_UPDATE_UPGRADE_INDEX	1u
69 #define AUTO_UPDATE_BLANK_INDEX		2u
70 #define AUTO_UPDATE_GOLDEN_DIRECTORY	(AUTO_UPDATE_DIRECTORY_WIDTH * AUTO_UPDATE_GOLDEN_INDEX)
71 #define AUTO_UPDATE_UPGRADE_DIRECTORY	(AUTO_UPDATE_DIRECTORY_WIDTH * AUTO_UPDATE_UPGRADE_INDEX)
72 #define AUTO_UPDATE_BLANK_DIRECTORY	(AUTO_UPDATE_DIRECTORY_WIDTH * AUTO_UPDATE_BLANK_INDEX)
73 #define AUTO_UPDATE_DIRECTORY_SIZE	SZ_1K
74 #define AUTO_UPDATE_RESERVED_SIZE	SZ_1M
75 #define AUTO_UPDATE_BITSTREAM_BASE	(AUTO_UPDATE_DIRECTORY_SIZE + AUTO_UPDATE_RESERVED_SIZE)
76 
77 #define AUTO_UPDATE_TIMEOUT_MS		60000
78 
79 struct mpfs_auto_update_priv {
80 	struct mpfs_sys_controller *sys_controller;
81 	struct device *dev;
82 	struct mtd_info *flash;
83 	struct fw_upload *fw_uploader;
84 	struct completion programming_complete;
85 	size_t size_per_bitstream;
86 	bool cancel_request;
87 };
88 
89 static enum fw_upload_err mpfs_auto_update_prepare(struct fw_upload *fw_uploader, const u8 *data,
90 						   u32 size)
91 {
92 	struct mpfs_auto_update_priv *priv = fw_uploader->dd_handle;
93 	size_t erase_size = AUTO_UPDATE_DIRECTORY_SIZE;
94 
95 	/*
96 	 * Verifying the Golden Image is idealistic. It will be evaluated
97 	 * against the currently programmed image and thus may fail - due to
98 	 * either rollback protection (if its an older version than that in use)
99 	 * or if the version is the same as that of the in-use image.
100 	 * Extracting the information as to why a failure occurred is not
101 	 * currently possible due to limitations of the system controller
102 	 * driver. If those are fixed, verification of the Golden Image should
103 	 * be added here.
104 	 */
105 
106 	priv->flash = mpfs_sys_controller_get_flash(priv->sys_controller);
107 	if (!priv->flash)
108 		return FW_UPLOAD_ERR_HW_ERROR;
109 
110 	erase_size = round_up(erase_size, (u64)priv->flash->erasesize);
111 
112 	/*
113 	 * We need to calculate if we have enough space in the flash for the
114 	 * new image.
115 	 * First, chop off the first 1 KiB as it's reserved for the directory.
116 	 * The 1 MiB reserved for design info needs to be ignored also.
117 	 * All that remains is carved into 3 & rounded down to the erasesize.
118 	 * If this is smaller than the image size, we abort.
119 	 * There's also no need to consume more than 20 MiB per image.
120 	 */
121 	priv->size_per_bitstream = priv->flash->size - SZ_1K - SZ_1M;
122 	priv->size_per_bitstream = round_down(priv->size_per_bitstream / 3, erase_size);
123 	if (priv->size_per_bitstream > 20 * SZ_1M)
124 		priv->size_per_bitstream = 20 * SZ_1M;
125 
126 	if (priv->size_per_bitstream < size) {
127 		dev_err(priv->dev,
128 			"flash device has insufficient capacity to store this bitstream\n");
129 		return FW_UPLOAD_ERR_INVALID_SIZE;
130 	}
131 
132 	priv->cancel_request = false;
133 
134 	return FW_UPLOAD_ERR_NONE;
135 }
136 
137 static void mpfs_auto_update_cancel(struct fw_upload *fw_uploader)
138 {
139 	struct mpfs_auto_update_priv *priv = fw_uploader->dd_handle;
140 
141 	priv->cancel_request = true;
142 }
143 
144 static enum fw_upload_err mpfs_auto_update_poll_complete(struct fw_upload *fw_uploader)
145 {
146 	struct mpfs_auto_update_priv *priv = fw_uploader->dd_handle;
147 	int ret;
148 
149 	/*
150 	 * There is no meaningful way to get the status of the programming while
151 	 * it is in progress, so attempting anything other than waiting for it
152 	 * to complete would be misplaced.
153 	 */
154 	ret = wait_for_completion_timeout(&priv->programming_complete,
155 					  msecs_to_jiffies(AUTO_UPDATE_TIMEOUT_MS));
156 	if (ret)
157 		return FW_UPLOAD_ERR_TIMEOUT;
158 
159 	return FW_UPLOAD_ERR_NONE;
160 }
161 
162 static int mpfs_auto_update_verify_image(struct fw_upload *fw_uploader)
163 {
164 	struct mpfs_auto_update_priv *priv = fw_uploader->dd_handle;
165 	struct mpfs_mss_response *response;
166 	struct mpfs_mss_msg *message;
167 	u32 *response_msg;
168 	int ret;
169 
170 	response_msg = devm_kzalloc(priv->dev, AUTO_UPDATE_FEATURE_RESP_SIZE * sizeof(*response_msg),
171 				    GFP_KERNEL);
172 	if (!response_msg)
173 		return -ENOMEM;
174 
175 	response = devm_kzalloc(priv->dev, sizeof(struct mpfs_mss_response), GFP_KERNEL);
176 	if (!response) {
177 		ret = -ENOMEM;
178 		goto free_response_msg;
179 	}
180 
181 	message = devm_kzalloc(priv->dev, sizeof(struct mpfs_mss_msg), GFP_KERNEL);
182 	if (!message) {
183 		ret = -ENOMEM;
184 		goto free_response;
185 	}
186 
187 	/*
188 	 * The system controller can verify that an image in the flash is valid.
189 	 * Rather than duplicate the check in this driver, call the relevant
190 	 * service from the system controller instead.
191 	 * This service has no command data and no response data. It overloads
192 	 * mbox_offset with the image index in the flash's SPI directory where
193 	 * the bitstream is located.
194 	 */
195 	response->resp_msg = response_msg;
196 	response->resp_size = AUTO_UPDATE_AUTHENTICATE_RESP_SIZE;
197 	message->cmd_opcode = AUTO_UPDATE_AUTHENTICATE_CMD_OPCODE;
198 	message->cmd_data_size = AUTO_UPDATE_AUTHENTICATE_CMD_DATA_SIZE;
199 	message->response = response;
200 	message->cmd_data = AUTO_UPDATE_AUTHENTICATE_CMD_DATA;
201 	message->mbox_offset = AUTO_UPDATE_UPGRADE_INDEX;
202 	message->resp_offset = AUTO_UPDATE_DEFAULT_RESP_OFFSET;
203 
204 	dev_info(priv->dev, "Running verification of Upgrade Image\n");
205 	ret = mpfs_blocking_transaction(priv->sys_controller, message);
206 	if (ret | response->resp_status) {
207 		dev_warn(priv->dev, "Verification of Upgrade Image failed!\n");
208 		ret = ret ? ret : -EBADMSG;
209 	}
210 
211 	dev_info(priv->dev, "Verification of Upgrade Image passed!\n");
212 
213 	devm_kfree(priv->dev, message);
214 free_response:
215 	devm_kfree(priv->dev, response);
216 free_response_msg:
217 	devm_kfree(priv->dev, response_msg);
218 
219 	return ret;
220 }
221 
222 static int mpfs_auto_update_set_image_address(struct mpfs_auto_update_priv *priv, char *buffer,
223 					      u32 image_address, loff_t directory_address)
224 {
225 	struct erase_info erase;
226 	size_t erase_size = AUTO_UPDATE_DIRECTORY_SIZE;
227 	size_t bytes_written = 0, bytes_read = 0;
228 	int ret;
229 
230 	erase_size = round_up(erase_size, (u64)priv->flash->erasesize);
231 
232 	erase.addr = AUTO_UPDATE_DIRECTORY_BASE;
233 	erase.len = erase_size;
234 
235 	/*
236 	 * We need to write the "SPI DIRECTORY" to the first 1 KiB, telling
237 	 * the system controller where to find the actual bitstream. Since
238 	 * this is spi-nor, we have to read the first eraseblock, erase that
239 	 * portion of the flash, modify the data and then write it back.
240 	 * There's no need to do this though if things are already the way they
241 	 * should be, so check and save the write in that case.
242 	 */
243 	ret = mtd_read(priv->flash, AUTO_UPDATE_DIRECTORY_BASE, erase_size, &bytes_read,
244 		       (u_char *)buffer);
245 	if (ret)
246 		return ret;
247 
248 	if (bytes_read != erase_size)
249 		return -EIO;
250 
251 	if ((*(u32 *)(buffer + AUTO_UPDATE_UPGRADE_DIRECTORY) == image_address) &&
252 	    !(*(u32 *)(buffer + AUTO_UPDATE_BLANK_DIRECTORY)))
253 		return 0;
254 
255 	ret = mtd_erase(priv->flash, &erase);
256 	if (ret)
257 		return ret;
258 
259 	/*
260 	 * Populate the image address and then zero out the next directory so
261 	 * that the system controller doesn't complain if in "Single Image"
262 	 * mode.
263 	 */
264 	memcpy(buffer + AUTO_UPDATE_UPGRADE_DIRECTORY, &image_address,
265 	       AUTO_UPDATE_DIRECTORY_WIDTH);
266 	memset(buffer + AUTO_UPDATE_BLANK_DIRECTORY, 0x0, AUTO_UPDATE_DIRECTORY_WIDTH);
267 
268 	dev_info(priv->dev, "Writing the image address (%x) to the flash directory (%llx)\n",
269 		 image_address, directory_address);
270 
271 	ret = mtd_write(priv->flash, 0x0, erase_size, &bytes_written, (u_char *)buffer);
272 	if (ret)
273 		return ret;
274 
275 	if (bytes_written != erase_size)
276 		return ret;
277 
278 	return 0;
279 }
280 
281 static int mpfs_auto_update_write_bitstream(struct fw_upload *fw_uploader, const u8 *data,
282 					    u32 offset, u32 size, u32 *written)
283 {
284 	struct mpfs_auto_update_priv *priv = fw_uploader->dd_handle;
285 	struct erase_info erase;
286 	char *buffer;
287 	loff_t directory_address = AUTO_UPDATE_UPGRADE_DIRECTORY;
288 	size_t erase_size = AUTO_UPDATE_DIRECTORY_SIZE;
289 	size_t bytes_written = 0;
290 	u32 image_address;
291 	int ret;
292 
293 	erase_size = round_up(erase_size, (u64)priv->flash->erasesize);
294 
295 	image_address = AUTO_UPDATE_BITSTREAM_BASE +
296 		AUTO_UPDATE_UPGRADE_INDEX * priv->size_per_bitstream;
297 
298 	buffer = devm_kzalloc(priv->dev, erase_size, GFP_KERNEL);
299 	if (!buffer)
300 		return -ENOMEM;
301 
302 	ret = mpfs_auto_update_set_image_address(priv, buffer, image_address, directory_address);
303 	if (ret) {
304 		dev_err(priv->dev, "failed to set image address in the SPI directory: %d\n", ret);
305 		goto out;
306 	}
307 
308 	/*
309 	 * Now the .spi image itself can be written to the flash. Preservation
310 	 * of contents here is not important here, unlike the spi "directory"
311 	 * which must be RMWed.
312 	 */
313 	erase.len = round_up(size, (size_t)priv->flash->erasesize);
314 	erase.addr = image_address;
315 
316 	dev_info(priv->dev, "Erasing the flash at address (%x)\n", image_address);
317 	ret = mtd_erase(priv->flash, &erase);
318 	if (ret)
319 		goto out;
320 
321 	/*
322 	 * No parsing etc of the bitstream is required. The system controller
323 	 * will do all of that itself - including verifying that the bitstream
324 	 * is valid.
325 	 */
326 	dev_info(priv->dev, "Writing the image to the flash at address (%x)\n", image_address);
327 	ret = mtd_write(priv->flash, (loff_t)image_address, size, &bytes_written, data);
328 	if (ret)
329 		goto out;
330 
331 	if (bytes_written != size) {
332 		ret = -EIO;
333 		goto out;
334 	}
335 
336 	*written = bytes_written;
337 
338 out:
339 	devm_kfree(priv->dev, buffer);
340 	return ret;
341 }
342 
343 static enum fw_upload_err mpfs_auto_update_write(struct fw_upload *fw_uploader, const u8 *data,
344 						 u32 offset, u32 size, u32 *written)
345 {
346 	struct mpfs_auto_update_priv *priv = fw_uploader->dd_handle;
347 	enum fw_upload_err err = FW_UPLOAD_ERR_NONE;
348 	int ret;
349 
350 	reinit_completion(&priv->programming_complete);
351 
352 	ret = mpfs_auto_update_write_bitstream(fw_uploader, data, offset, size, written);
353 	if (ret) {
354 		err = FW_UPLOAD_ERR_RW_ERROR;
355 		goto out;
356 	}
357 
358 	if (priv->cancel_request) {
359 		err = FW_UPLOAD_ERR_CANCELED;
360 		goto out;
361 	}
362 
363 	ret = mpfs_auto_update_verify_image(fw_uploader);
364 	if (ret)
365 		err = FW_UPLOAD_ERR_FW_INVALID;
366 
367 out:
368 	complete(&priv->programming_complete);
369 
370 	return err;
371 }
372 
373 static const struct fw_upload_ops mpfs_auto_update_ops = {
374 	.prepare = mpfs_auto_update_prepare,
375 	.write = mpfs_auto_update_write,
376 	.poll_complete = mpfs_auto_update_poll_complete,
377 	.cancel = mpfs_auto_update_cancel,
378 };
379 
380 static int mpfs_auto_update_available(struct mpfs_auto_update_priv *priv)
381 {
382 	struct mpfs_mss_response *response;
383 	struct mpfs_mss_msg *message;
384 	u32 *response_msg;
385 	int ret;
386 
387 	response_msg = devm_kzalloc(priv->dev,
388 				    AUTO_UPDATE_FEATURE_RESP_SIZE * sizeof(*response_msg),
389 				    GFP_KERNEL);
390 	if (!response_msg)
391 		return -ENOMEM;
392 
393 	response = devm_kzalloc(priv->dev, sizeof(struct mpfs_mss_response), GFP_KERNEL);
394 	if (!response)
395 		return -ENOMEM;
396 
397 	message = devm_kzalloc(priv->dev, sizeof(struct mpfs_mss_msg), GFP_KERNEL);
398 	if (!message)
399 		return -ENOMEM;
400 
401 	/*
402 	 * To verify that Auto Update is possible, the "Query Security Service
403 	 * Request" is performed.
404 	 * This service has no command data & does not overload mbox_offset.
405 	 */
406 	response->resp_msg = response_msg;
407 	response->resp_size = AUTO_UPDATE_FEATURE_RESP_SIZE;
408 	message->cmd_opcode = AUTO_UPDATE_FEATURE_CMD_OPCODE;
409 	message->cmd_data_size = AUTO_UPDATE_FEATURE_CMD_DATA_SIZE;
410 	message->response = response;
411 	message->cmd_data = AUTO_UPDATE_FEATURE_CMD_DATA;
412 	message->mbox_offset = AUTO_UPDATE_DEFAULT_MBOX_OFFSET;
413 	message->resp_offset = AUTO_UPDATE_DEFAULT_RESP_OFFSET;
414 
415 	ret = mpfs_blocking_transaction(priv->sys_controller, message);
416 	if (ret)
417 		return ret;
418 
419 	/*
420 	 * Currently, the system controller's firmware does not generate any
421 	 * interrupts for failed services, so mpfs_blocking_transaction() should
422 	 * time out & therefore return an error.
423 	 * Hitting this check is highly unlikely at present, but if the system
424 	 * controller's behaviour changes so that it does generate interrupts
425 	 * for failed services, it will be required.
426 	 */
427 	if (response->resp_status)
428 		return -EIO;
429 
430 	/*
431 	 * Bit 5 of byte 1 is "UL_Auto Update" & if it is set, Auto Update is
432 	 * not possible.
433 	 */
434 	if (response_msg[1] & AUTO_UPDATE_FEATURE_ENABLED)
435 		return -EPERM;
436 
437 	return 0;
438 }
439 
440 static int mpfs_auto_update_probe(struct platform_device *pdev)
441 {
442 	struct device *dev = &pdev->dev;
443 	struct mpfs_auto_update_priv *priv;
444 	struct fw_upload *fw_uploader;
445 	int ret;
446 
447 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
448 	if (!priv)
449 		return -ENOMEM;
450 
451 	priv->sys_controller = mpfs_sys_controller_get(dev);
452 	if (IS_ERR(priv->sys_controller))
453 		return dev_err_probe(dev, PTR_ERR(priv->sys_controller),
454 				     "Could not register as a sub device of the system controller\n");
455 
456 	priv->dev = dev;
457 	platform_set_drvdata(pdev, priv);
458 
459 	ret = mpfs_auto_update_available(priv);
460 	if (ret)
461 		return dev_err_probe(dev, ret,
462 				     "The current bitstream does not support auto-update\n");
463 
464 	init_completion(&priv->programming_complete);
465 
466 	fw_uploader = firmware_upload_register(THIS_MODULE, dev, "mpfs-auto-update",
467 					       &mpfs_auto_update_ops, priv);
468 	if (IS_ERR(fw_uploader))
469 		return dev_err_probe(dev, PTR_ERR(fw_uploader),
470 				     "Failed to register the bitstream uploader\n");
471 
472 	priv->fw_uploader = fw_uploader;
473 
474 	return 0;
475 }
476 
477 static void mpfs_auto_update_remove(struct platform_device *pdev)
478 {
479 	struct mpfs_auto_update_priv *priv = platform_get_drvdata(pdev);
480 
481 	firmware_upload_unregister(priv->fw_uploader);
482 }
483 
484 static struct platform_driver mpfs_auto_update_driver = {
485 	.driver = {
486 		.name = "mpfs-auto-update",
487 	},
488 	.probe = mpfs_auto_update_probe,
489 	.remove_new = mpfs_auto_update_remove,
490 };
491 module_platform_driver(mpfs_auto_update_driver);
492 
493 MODULE_LICENSE("GPL");
494 MODULE_AUTHOR("Conor Dooley <conor.dooley@microchip.com>");
495 MODULE_DESCRIPTION("PolarFire SoC Auto Update FPGA reprogramming");
496