xref: /openbmc/linux/drivers/infiniband/hw/hfi1/eprom.c (revision 8cb5d748)
1 /*
2  * Copyright(c) 2015, 2016 Intel Corporation.
3  *
4  * This file is provided under a dual BSD/GPLv2 license.  When using or
5  * redistributing this file, you may do so under either license.
6  *
7  * GPL LICENSE SUMMARY
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of version 2 of the GNU General Public License as
11  * published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful, but
14  * WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * General Public License for more details.
17  *
18  * BSD LICENSE
19  *
20  * Redistribution and use in source and binary forms, with or without
21  * modification, are permitted provided that the following conditions
22  * are met:
23  *
24  *  - Redistributions of source code must retain the above copyright
25  *    notice, this list of conditions and the following disclaimer.
26  *  - Redistributions in binary form must reproduce the above copyright
27  *    notice, this list of conditions and the following disclaimer in
28  *    the documentation and/or other materials provided with the
29  *    distribution.
30  *  - Neither the name of Intel Corporation nor the names of its
31  *    contributors may be used to endorse or promote products derived
32  *    from this software without specific prior written permission.
33  *
34  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
35  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
36  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
37  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
38  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
39  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
40  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
41  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
42  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
43  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
44  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
45  *
46  */
47 #include <linux/delay.h>
48 #include "hfi.h"
49 #include "common.h"
50 #include "eprom.h"
51 
52 /*
53  * The EPROM is logically divided into three partitions:
54  *	partition 0: the first 128K, visible from PCI ROM BAR
55  *	partition 1: 4K config file (sector size)
56  *	partition 2: the rest
57  */
58 #define P0_SIZE (128 * 1024)
59 #define P1_SIZE   (4 * 1024)
60 #define P1_START P0_SIZE
61 #define P2_START (P0_SIZE + P1_SIZE)
62 
63 /* controller page size, in bytes */
64 #define EP_PAGE_SIZE 256
65 #define EP_PAGE_MASK (EP_PAGE_SIZE - 1)
66 #define EP_PAGE_DWORDS (EP_PAGE_SIZE / sizeof(u32))
67 
68 /* controller commands */
69 #define CMD_SHIFT 24
70 #define CMD_NOP			    (0)
71 #define CMD_READ_DATA(addr)	    ((0x03 << CMD_SHIFT) | addr)
72 #define CMD_RELEASE_POWERDOWN_NOID  ((0xab << CMD_SHIFT))
73 
74 /* controller interface speeds */
75 #define EP_SPEED_FULL 0x2	/* full speed */
76 
77 /*
78  * How long to wait for the EPROM to become available, in ms.
79  * The spec 32 Mb EPROM takes around 40s to erase then write.
80  * Double it for safety.
81  */
82 #define EPROM_TIMEOUT 80000 /* ms */
83 
84 /*
85  * Read a 256 byte (64 dword) EPROM page.
86  * All callers have verified the offset is at a page boundary.
87  */
88 static void read_page(struct hfi1_devdata *dd, u32 offset, u32 *result)
89 {
90 	int i;
91 
92 	write_csr(dd, ASIC_EEP_ADDR_CMD, CMD_READ_DATA(offset));
93 	for (i = 0; i < EP_PAGE_DWORDS; i++)
94 		result[i] = (u32)read_csr(dd, ASIC_EEP_DATA);
95 	write_csr(dd, ASIC_EEP_ADDR_CMD, CMD_NOP); /* close open page */
96 }
97 
98 /*
99  * Read length bytes starting at offset from the start of the EPROM.
100  */
101 static int read_length(struct hfi1_devdata *dd, u32 start, u32 len, void *dest)
102 {
103 	u32 buffer[EP_PAGE_DWORDS];
104 	u32 end;
105 	u32 start_offset;
106 	u32 read_start;
107 	u32 bytes;
108 
109 	if (len == 0)
110 		return 0;
111 
112 	end = start + len;
113 
114 	/*
115 	 * Make sure the read range is not outside of the controller read
116 	 * command address range.  Note that '>' is correct below - the end
117 	 * of the range is OK if it stops at the limit, but no higher.
118 	 */
119 	if (end > (1 << CMD_SHIFT))
120 		return -EINVAL;
121 
122 	/* read the first partial page */
123 	start_offset = start & EP_PAGE_MASK;
124 	if (start_offset) {
125 		/* partial starting page */
126 
127 		/* align and read the page that contains the start */
128 		read_start = start & ~EP_PAGE_MASK;
129 		read_page(dd, read_start, buffer);
130 
131 		/* the rest of the page is available data */
132 		bytes = EP_PAGE_SIZE - start_offset;
133 
134 		if (len <= bytes) {
135 			/* end is within this page */
136 			memcpy(dest, (u8 *)buffer + start_offset, len);
137 			return 0;
138 		}
139 
140 		memcpy(dest, (u8 *)buffer + start_offset, bytes);
141 
142 		start += bytes;
143 		len -= bytes;
144 		dest += bytes;
145 	}
146 	/* start is now page aligned */
147 
148 	/* read whole pages */
149 	while (len >= EP_PAGE_SIZE) {
150 		read_page(dd, start, buffer);
151 		memcpy(dest, buffer, EP_PAGE_SIZE);
152 
153 		start += EP_PAGE_SIZE;
154 		len -= EP_PAGE_SIZE;
155 		dest += EP_PAGE_SIZE;
156 	}
157 
158 	/* read the last partial page */
159 	if (len) {
160 		read_page(dd, start, buffer);
161 		memcpy(dest, buffer, len);
162 	}
163 
164 	return 0;
165 }
166 
167 /*
168  * Initialize the EPROM handler.
169  */
170 int eprom_init(struct hfi1_devdata *dd)
171 {
172 	int ret = 0;
173 
174 	/* only the discrete chip has an EPROM */
175 	if (dd->pcidev->device != PCI_DEVICE_ID_INTEL0)
176 		return 0;
177 
178 	/*
179 	 * It is OK if both HFIs reset the EPROM as long as they don't
180 	 * do it at the same time.
181 	 */
182 	ret = acquire_chip_resource(dd, CR_EPROM, EPROM_TIMEOUT);
183 	if (ret) {
184 		dd_dev_err(dd,
185 			   "%s: unable to acquire EPROM resource, no EPROM support\n",
186 			   __func__);
187 		goto done_asic;
188 	}
189 
190 	/* reset EPROM to be sure it is in a good state */
191 
192 	/* set reset */
193 	write_csr(dd, ASIC_EEP_CTL_STAT, ASIC_EEP_CTL_STAT_EP_RESET_SMASK);
194 	/* clear reset, set speed */
195 	write_csr(dd, ASIC_EEP_CTL_STAT,
196 		  EP_SPEED_FULL << ASIC_EEP_CTL_STAT_RATE_SPI_SHIFT);
197 
198 	/* wake the device with command "release powerdown NoID" */
199 	write_csr(dd, ASIC_EEP_ADDR_CMD, CMD_RELEASE_POWERDOWN_NOID);
200 
201 	dd->eprom_available = true;
202 	release_chip_resource(dd, CR_EPROM);
203 done_asic:
204 	return ret;
205 }
206 
207 /* magic character sequence that begins an image */
208 #define IMAGE_START_MAGIC "APO="
209 
210 /* magic character sequence that might trail an image */
211 #define IMAGE_TRAIL_MAGIC "egamiAPO"
212 
213 /* EPROM file types */
214 #define HFI1_EFT_PLATFORM_CONFIG 2
215 
216 /* segment size - 128 KiB */
217 #define SEG_SIZE (128 * 1024)
218 
219 struct hfi1_eprom_footer {
220 	u32 oprom_size;		/* size of the oprom, in bytes */
221 	u16 num_table_entries;
222 	u16 version;		/* version of this footer */
223 	u32 magic;		/* must be last */
224 };
225 
226 struct hfi1_eprom_table_entry {
227 	u32 type;		/* file type */
228 	u32 offset;		/* file offset from start of EPROM */
229 	u32 size;		/* file size, in bytes */
230 };
231 
232 /*
233  * Calculate the max number of table entries that will fit within a directory
234  * buffer of size 'dir_size'.
235  */
236 #define MAX_TABLE_ENTRIES(dir_size) \
237 	(((dir_size) - sizeof(struct hfi1_eprom_footer)) / \
238 		sizeof(struct hfi1_eprom_table_entry))
239 
240 #define DIRECTORY_SIZE(n) (sizeof(struct hfi1_eprom_footer) + \
241 	(sizeof(struct hfi1_eprom_table_entry) * (n)))
242 
243 #define MAGIC4(a, b, c, d) ((d) << 24 | (c) << 16 | (b) << 8 | (a))
244 #define FOOTER_MAGIC MAGIC4('e', 'p', 'r', 'm')
245 #define FOOTER_VERSION 1
246 
247 /*
248  * Read all of partition 1.  The actual file is at the front.  Adjust
249  * the returned size if a trailing image magic is found.
250  */
251 static int read_partition_platform_config(struct hfi1_devdata *dd, void **data,
252 					  u32 *size)
253 {
254 	void *buffer;
255 	void *p;
256 	u32 length;
257 	int ret;
258 
259 	buffer = kmalloc(P1_SIZE, GFP_KERNEL);
260 	if (!buffer)
261 		return -ENOMEM;
262 
263 	ret = read_length(dd, P1_START, P1_SIZE, buffer);
264 	if (ret) {
265 		kfree(buffer);
266 		return ret;
267 	}
268 
269 	/* config partition is valid only if it starts with IMAGE_START_MAGIC */
270 	if (memcmp(buffer, IMAGE_START_MAGIC, strlen(IMAGE_START_MAGIC))) {
271 		kfree(buffer);
272 		return -ENOENT;
273 	}
274 
275 	/* scan for image magic that may trail the actual data */
276 	p = strnstr(buffer, IMAGE_TRAIL_MAGIC, P1_SIZE);
277 	if (p)
278 		length = p - buffer;
279 	else
280 		length = P1_SIZE;
281 
282 	*data = buffer;
283 	*size = length;
284 	return 0;
285 }
286 
287 /*
288  * The segment magic has been checked.  There is a footer and table of
289  * contents present.
290  *
291  * directory is a u32 aligned buffer of size EP_PAGE_SIZE.
292  */
293 static int read_segment_platform_config(struct hfi1_devdata *dd,
294 					void *directory, void **data, u32 *size)
295 {
296 	struct hfi1_eprom_footer *footer;
297 	struct hfi1_eprom_table_entry *table;
298 	struct hfi1_eprom_table_entry *entry;
299 	void *buffer = NULL;
300 	void *table_buffer = NULL;
301 	int ret, i;
302 	u32 directory_size;
303 	u32 seg_base, seg_offset;
304 	u32 bytes_available, ncopied, to_copy;
305 
306 	/* the footer is at the end of the directory */
307 	footer = (struct hfi1_eprom_footer *)
308 			(directory + EP_PAGE_SIZE - sizeof(*footer));
309 
310 	/* make sure the structure version is supported */
311 	if (footer->version != FOOTER_VERSION)
312 		return -EINVAL;
313 
314 	/* oprom size cannot be larger than a segment */
315 	if (footer->oprom_size >= SEG_SIZE)
316 		return -EINVAL;
317 
318 	/* the file table must fit in a segment with the oprom */
319 	if (footer->num_table_entries >
320 			MAX_TABLE_ENTRIES(SEG_SIZE - footer->oprom_size))
321 		return -EINVAL;
322 
323 	/* find the file table start, which precedes the footer */
324 	directory_size = DIRECTORY_SIZE(footer->num_table_entries);
325 	if (directory_size <= EP_PAGE_SIZE) {
326 		/* the file table fits into the directory buffer handed in */
327 		table = (struct hfi1_eprom_table_entry *)
328 				(directory + EP_PAGE_SIZE - directory_size);
329 	} else {
330 		/* need to allocate and read more */
331 		table_buffer = kmalloc(directory_size, GFP_KERNEL);
332 		if (!table_buffer)
333 			return -ENOMEM;
334 		ret = read_length(dd, SEG_SIZE - directory_size,
335 				  directory_size, table_buffer);
336 		if (ret)
337 			goto done;
338 		table = table_buffer;
339 	}
340 
341 	/* look for the platform configuration file in the table */
342 	for (entry = NULL, i = 0; i < footer->num_table_entries; i++) {
343 		if (table[i].type == HFI1_EFT_PLATFORM_CONFIG) {
344 			entry = &table[i];
345 			break;
346 		}
347 	}
348 	if (!entry) {
349 		ret = -ENOENT;
350 		goto done;
351 	}
352 
353 	/*
354 	 * Sanity check on the configuration file size - it should never
355 	 * be larger than 4 KiB.
356 	 */
357 	if (entry->size > (4 * 1024)) {
358 		dd_dev_err(dd, "Bad configuration file size 0x%x\n",
359 			   entry->size);
360 		ret = -EINVAL;
361 		goto done;
362 	}
363 
364 	/* check for bogus offset and size that wrap when added together */
365 	if (entry->offset + entry->size < entry->offset) {
366 		dd_dev_err(dd,
367 			   "Bad configuration file start + size 0x%x+0x%x\n",
368 			   entry->offset, entry->size);
369 		ret = -EINVAL;
370 		goto done;
371 	}
372 
373 	/* allocate the buffer to return */
374 	buffer = kmalloc(entry->size, GFP_KERNEL);
375 	if (!buffer) {
376 		ret = -ENOMEM;
377 		goto done;
378 	}
379 
380 	/*
381 	 * Extract the file by looping over segments until it is fully read.
382 	 */
383 	seg_offset = entry->offset % SEG_SIZE;
384 	seg_base = entry->offset - seg_offset;
385 	ncopied = 0;
386 	while (ncopied < entry->size) {
387 		/* calculate data bytes available in this segment */
388 
389 		/* start with the bytes from the current offset to the end */
390 		bytes_available = SEG_SIZE - seg_offset;
391 		/* subtract off footer and table from segment 0 */
392 		if (seg_base == 0) {
393 			/*
394 			 * Sanity check: should not have a starting point
395 			 * at or within the directory.
396 			 */
397 			if (bytes_available <= directory_size) {
398 				dd_dev_err(dd,
399 					   "Bad configuration file - offset 0x%x within footer+table\n",
400 					   entry->offset);
401 				ret = -EINVAL;
402 				goto done;
403 			}
404 			bytes_available -= directory_size;
405 		}
406 
407 		/* calculate bytes wanted */
408 		to_copy = entry->size - ncopied;
409 
410 		/* max out at the available bytes in this segment */
411 		if (to_copy > bytes_available)
412 			to_copy = bytes_available;
413 
414 		/*
415 		 * Read from the EPROM.
416 		 *
417 		 * The sanity check for entry->offset is done in read_length().
418 		 * The EPROM offset is validated against what the hardware
419 		 * addressing supports.  In addition, if the offset is larger
420 		 * than the actual EPROM, it silently wraps.  It will work
421 		 * fine, though the reader may not get what they expected
422 		 * from the EPROM.
423 		 */
424 		ret = read_length(dd, seg_base + seg_offset, to_copy,
425 				  buffer + ncopied);
426 		if (ret)
427 			goto done;
428 
429 		ncopied += to_copy;
430 
431 		/* set up for next segment */
432 		seg_offset = footer->oprom_size;
433 		seg_base += SEG_SIZE;
434 	}
435 
436 	/* success */
437 	ret = 0;
438 	*data = buffer;
439 	*size = entry->size;
440 
441 done:
442 	kfree(table_buffer);
443 	if (ret)
444 		kfree(buffer);
445 	return ret;
446 }
447 
448 /*
449  * Read the platform configuration file from the EPROM.
450  *
451  * On success, an allocated buffer containing the data and its size are
452  * returned.  It is up to the caller to free this buffer.
453  *
454  * Return value:
455  *   0	      - success
456  *   -ENXIO   - no EPROM is available
457  *   -EBUSY   - not able to acquire access to the EPROM
458  *   -ENOENT  - no recognizable file written
459  *   -ENOMEM  - buffer could not be allocated
460  *   -EINVAL  - invalid EPROM contentents found
461  */
462 int eprom_read_platform_config(struct hfi1_devdata *dd, void **data, u32 *size)
463 {
464 	u32 directory[EP_PAGE_DWORDS]; /* aligned buffer */
465 	int ret;
466 
467 	if (!dd->eprom_available)
468 		return -ENXIO;
469 
470 	ret = acquire_chip_resource(dd, CR_EPROM, EPROM_TIMEOUT);
471 	if (ret)
472 		return -EBUSY;
473 
474 	/* read the last page of the segment for the EPROM format magic */
475 	ret = read_length(dd, SEG_SIZE - EP_PAGE_SIZE, EP_PAGE_SIZE, directory);
476 	if (ret)
477 		goto done;
478 
479 	/* last dword of the segment contains a magic value */
480 	if (directory[EP_PAGE_DWORDS - 1] == FOOTER_MAGIC) {
481 		/* segment format */
482 		ret = read_segment_platform_config(dd, directory, data, size);
483 	} else {
484 		/* partition format */
485 		ret = read_partition_platform_config(dd, data, size);
486 	}
487 
488 done:
489 	release_chip_resource(dd, CR_EPROM);
490 	return ret;
491 }
492