Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
/*
 * Copyright(c) 2015, 2016 Intel Corporation.
 *
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * BSD LICENSE
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  - Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  - Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *  - Neither the name of Intel Corporation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */
#include <linux/delay.h>
#include "hfi.h"
#include "common.h"
#include "eprom.h"

/*
 * The EPROM is logically divided into three partitions:
 *	partition 0: the first 128K, visible from PCI ROM BAR
 *	partition 1: 4K config file (sector size)
 *	partition 2: the rest
 */
#define P0_SIZE (128 * 1024)
#define P1_SIZE   (4 * 1024)
#define P1_START P0_SIZE
#define P2_START (P0_SIZE + P1_SIZE)

/* controller page size, in bytes */
#define EP_PAGE_SIZE 256
#define EP_PAGE_MASK (EP_PAGE_SIZE - 1)
#define EP_PAGE_DWORDS (EP_PAGE_SIZE / sizeof(u32))

/* controller commands */
#define CMD_SHIFT 24
#define CMD_NOP			    (0)
#define CMD_READ_DATA(addr)	    ((0x03 << CMD_SHIFT) | addr)
#define CMD_RELEASE_POWERDOWN_NOID  ((0xab << CMD_SHIFT))

/* controller interface speeds */
#define EP_SPEED_FULL 0x2	/* full speed */

/*
 * How long to wait for the EPROM to become available, in ms.
 * The spec 32 Mb EPROM takes around 40s to erase then write.
 * Double it for safety.
 */
#define EPROM_TIMEOUT 80000 /* ms */

/*
 * Read a 256 byte (64 dword) EPROM page.
 * All callers have verified the offset is at a page boundary.
 */
static void read_page(struct hfi1_devdata *dd, u32 offset, u32 *result)
{
	int i;

	write_csr(dd, ASIC_EEP_ADDR_CMD, CMD_READ_DATA(offset));
	for (i = 0; i < EP_PAGE_DWORDS; i++)
		result[i] = (u32)read_csr(dd, ASIC_EEP_DATA);
	write_csr(dd, ASIC_EEP_ADDR_CMD, CMD_NOP); /* close open page */
}

/*
 * Read length bytes starting at offset from the start of the EPROM.
 */
static int read_length(struct hfi1_devdata *dd, u32 start, u32 len, void *dest)
{
	u32 buffer[EP_PAGE_DWORDS];
	u32 end;
	u32 start_offset;
	u32 read_start;
	u32 bytes;

	if (len == 0)
		return 0;

	end = start + len;

	/*
	 * Make sure the read range is not outside of the controller read
	 * command address range.  Note that '>' is correct below - the end
	 * of the range is OK if it stops at the limit, but no higher.
	 */
	if (end > (1 << CMD_SHIFT))
		return -EINVAL;

	/* read the first partial page */
	start_offset = start & EP_PAGE_MASK;
	if (start_offset) {
		/* partial starting page */

		/* align and read the page that contains the start */
		read_start = start & ~EP_PAGE_MASK;
		read_page(dd, read_start, buffer);

		/* the rest of the page is available data */
		bytes = EP_PAGE_SIZE - start_offset;

		if (len <= bytes) {
			/* end is within this page */
			memcpy(dest, (u8 *)buffer + start_offset, len);
			return 0;
		}

		memcpy(dest, (u8 *)buffer + start_offset, bytes);

		start += bytes;
		len -= bytes;
		dest += bytes;
	}
	/* start is now page aligned */

	/* read whole pages */
	while (len >= EP_PAGE_SIZE) {
		read_page(dd, start, buffer);
		memcpy(dest, buffer, EP_PAGE_SIZE);

		start += EP_PAGE_SIZE;
		len -= EP_PAGE_SIZE;
		dest += EP_PAGE_SIZE;
	}

	/* read the last partial page */
	if (len) {
		read_page(dd, start, buffer);
		memcpy(dest, buffer, len);
	}

	return 0;
}

/*
 * Initialize the EPROM handler.
 */
int eprom_init(struct hfi1_devdata *dd)
{
	int ret = 0;

	/* only the discrete chip has an EPROM */
	if (dd->pcidev->device != PCI_DEVICE_ID_INTEL0)
		return 0;

	/*
	 * It is OK if both HFIs reset the EPROM as long as they don't
	 * do it at the same time.
	 */
	ret = acquire_chip_resource(dd, CR_EPROM, EPROM_TIMEOUT);
	if (ret) {
		dd_dev_err(dd,
			   "%s: unable to acquire EPROM resource, no EPROM support\n",
			   __func__);
		goto done_asic;
	}

	/* reset EPROM to be sure it is in a good state */

	/* set reset */
	write_csr(dd, ASIC_EEP_CTL_STAT, ASIC_EEP_CTL_STAT_EP_RESET_SMASK);
	/* clear reset, set speed */
	write_csr(dd, ASIC_EEP_CTL_STAT,
		  EP_SPEED_FULL << ASIC_EEP_CTL_STAT_RATE_SPI_SHIFT);

	/* wake the device with command "release powerdown NoID" */
	write_csr(dd, ASIC_EEP_ADDR_CMD, CMD_RELEASE_POWERDOWN_NOID);

	dd->eprom_available = true;
	release_chip_resource(dd, CR_EPROM);
done_asic:
	return ret;
}

/* magic character sequence that trails an image */
#define IMAGE_TRAIL_MAGIC "egamiAPO"

/* EPROM file types */
#define HFI1_EFT_PLATFORM_CONFIG 2

/* segment size - 128 KiB */
#define SEG_SIZE (128 * 1024)

struct hfi1_eprom_footer {
	u32 oprom_size;		/* size of the oprom, in bytes */
	u16 num_table_entries;
	u16 version;		/* version of this footer */
	u32 magic;		/* must be last */
};

struct hfi1_eprom_table_entry {
	u32 type;		/* file type */
	u32 offset;		/* file offset from start of EPROM */
	u32 size;		/* file size, in bytes */
};

/*
 * Calculate the max number of table entries that will fit within a directory
 * buffer of size 'dir_size'.
 */
#define MAX_TABLE_ENTRIES(dir_size) \
	(((dir_size) - sizeof(struct hfi1_eprom_footer)) / \
		sizeof(struct hfi1_eprom_table_entry))

#define DIRECTORY_SIZE(n) (sizeof(struct hfi1_eprom_footer) + \
	(sizeof(struct hfi1_eprom_table_entry) * (n)))

#define MAGIC4(a, b, c, d) ((d) << 24 | (c) << 16 | (b) << 8 | (a))
#define FOOTER_MAGIC MAGIC4('e', 'p', 'r', 'm')
#define FOOTER_VERSION 1

/*
 * Read all of partition 1.  The actual file is at the front.  Adjust
 * the returned size if a trailing image magic is found.
 */
static int read_partition_platform_config(struct hfi1_devdata *dd, void **data,
					  u32 *size)
{
	void *buffer;
	void *p;
	u32 length;
	int ret;

	buffer = kmalloc(P1_SIZE, GFP_KERNEL);
	if (!buffer)
		return -ENOMEM;

	ret = read_length(dd, P1_START, P1_SIZE, buffer);
	if (ret) {
		kfree(buffer);
		return ret;
	}

	/* scan for image magic that may trail the actual data */
	p = strnstr(buffer, IMAGE_TRAIL_MAGIC, P1_SIZE);
	if (p)
		length = p - buffer;
	else
		length = P1_SIZE;

	*data = buffer;
	*size = length;
	return 0;
}

/*
 * The segment magic has been checked.  There is a footer and table of
 * contents present.
 *
 * directory is a u32 aligned buffer of size EP_PAGE_SIZE.
 */
static int read_segment_platform_config(struct hfi1_devdata *dd,
					void *directory, void **data, u32 *size)
{
	struct hfi1_eprom_footer *footer;
	struct hfi1_eprom_table_entry *table;
	struct hfi1_eprom_table_entry *entry;
	void *buffer = NULL;
	void *table_buffer = NULL;
	int ret, i;
	u32 directory_size;
	u32 seg_base, seg_offset;
	u32 bytes_available, ncopied, to_copy;

	/* the footer is at the end of the directory */
	footer = (struct hfi1_eprom_footer *)
			(directory + EP_PAGE_SIZE - sizeof(*footer));

	/* make sure the structure version is supported */
	if (footer->version != FOOTER_VERSION)
		return -EINVAL;

	/* oprom size cannot be larger than a segment */
	if (footer->oprom_size >= SEG_SIZE)
		return -EINVAL;

	/* the file table must fit in a segment with the oprom */
	if (footer->num_table_entries >
			MAX_TABLE_ENTRIES(SEG_SIZE - footer->oprom_size))
		return -EINVAL;

	/* find the file table start, which precedes the footer */
	directory_size = DIRECTORY_SIZE(footer->num_table_entries);
	if (directory_size <= EP_PAGE_SIZE) {
		/* the file table fits into the directory buffer handed in */
		table = (struct hfi1_eprom_table_entry *)
				(directory + EP_PAGE_SIZE - directory_size);
	} else {
		/* need to allocate and read more */
		table_buffer = kmalloc(directory_size, GFP_KERNEL);
		if (!table_buffer)
			return -ENOMEM;
		ret = read_length(dd, SEG_SIZE - directory_size,
				  directory_size, table_buffer);
		if (ret)
			goto done;
		table = table_buffer;
	}

	/* look for the platform configuration file in the table */
	for (entry = NULL, i = 0; i < footer->num_table_entries; i++) {
		if (table[i].type == HFI1_EFT_PLATFORM_CONFIG) {
			entry = &table[i];
			break;
		}
	}
	if (!entry) {
		ret = -ENOENT;
		goto done;
	}

	/*
	 * Sanity check on the configuration file size - it should never
	 * be larger than 4 KiB.
	 */
	if (entry->size > (4 * 1024)) {
		dd_dev_err(dd, "Bad configuration file size 0x%x\n",
			   entry->size);
		ret = -EINVAL;
		goto done;
	}

	/* check for bogus offset and size that wrap when added together */
	if (entry->offset + entry->size < entry->offset) {
		dd_dev_err(dd,
			   "Bad configuration file start + size 0x%x+0x%x\n",
			   entry->offset, entry->size);
		ret = -EINVAL;
		goto done;
	}

	/* allocate the buffer to return */
	buffer = kmalloc(entry->size, GFP_KERNEL);
	if (!buffer) {
		ret = -ENOMEM;
		goto done;
	}

	/*
	 * Extract the file by looping over segments until it is fully read.
	 */
	seg_offset = entry->offset % SEG_SIZE;
	seg_base = entry->offset - seg_offset;
	ncopied = 0;
	while (ncopied < entry->size) {
		/* calculate data bytes available in this segment */

		/* start with the bytes from the current offset to the end */
		bytes_available = SEG_SIZE - seg_offset;
		/* subtract off footer and table from segment 0 */
		if (seg_base == 0) {
			/*
			 * Sanity check: should not have a starting point
			 * at or within the directory.
			 */
			if (bytes_available <= directory_size) {
				dd_dev_err(dd,
					   "Bad configuration file - offset 0x%x within footer+table\n",
					   entry->offset);
				ret = -EINVAL;
				goto done;
			}
			bytes_available -= directory_size;
		}

		/* calculate bytes wanted */
		to_copy = entry->size - ncopied;

		/* max out at the available bytes in this segment */
		if (to_copy > bytes_available)
			to_copy = bytes_available;

		/*
		 * Read from the EPROM.
		 *
		 * The sanity check for entry->offset is done in read_length().
		 * The EPROM offset is validated against what the hardware
		 * addressing supports.  In addition, if the offset is larger
		 * than the actual EPROM, it silently wraps.  It will work
		 * fine, though the reader may not get what they expected
		 * from the EPROM.
		 */
		ret = read_length(dd, seg_base + seg_offset, to_copy,
				  buffer + ncopied);
		if (ret)
			goto done;

		ncopied += to_copy;

		/* set up for next segment */
		seg_offset = footer->oprom_size;
		seg_base += SEG_SIZE;
	}

	/* success */
	ret = 0;
	*data = buffer;
	*size = entry->size;

done:
	kfree(table_buffer);
	if (ret)
		kfree(buffer);
	return ret;
}

/*
 * Read the platform configuration file from the EPROM.
 *
 * On success, an allocated buffer containing the data and its size are
 * returned.  It is up to the caller to free this buffer.
 *
 * Return value:
 *   0	      - success
 *   -ENXIO   - no EPROM is available
 *   -EBUSY   - not able to acquire access to the EPROM
 *   -ENOENT  - no recognizable file written
 *   -ENOMEM  - buffer could not be allocated
 *   -EINVAL  - invalid EPROM contentents found
 */
int eprom_read_platform_config(struct hfi1_devdata *dd, void **data, u32 *size)
{
	u32 directory[EP_PAGE_DWORDS]; /* aligned buffer */
	int ret;

	if (!dd->eprom_available)
		return -ENXIO;

	ret = acquire_chip_resource(dd, CR_EPROM, EPROM_TIMEOUT);
	if (ret)
		return -EBUSY;

	/* read the last page of the segment for the EPROM format magic */
	ret = read_length(dd, SEG_SIZE - EP_PAGE_SIZE, EP_PAGE_SIZE, directory);
	if (ret)
		goto done;

	/* last dword of the segment contains a magic value */
	if (directory[EP_PAGE_DWORDS - 1] == FOOTER_MAGIC) {
		/* segment format */
		ret = read_segment_platform_config(dd, directory, data, size);
	} else {
		/* partition format */
		ret = read_partition_platform_config(dd, data, size);
	}

done:
	release_chip_resource(dd, CR_EPROM);
	return ret;
}