1// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
2/*
3 * Copyright(c) 2015, 2016 Intel Corporation.
4 */
5
6#include <linux/delay.h>
7#include "hfi.h"
8#include "common.h"
9#include "eprom.h"
10
11/*
12 * The EPROM is logically divided into three partitions:
13 * partition 0: the first 128K, visible from PCI ROM BAR
14 * partition 1: 4K config file (sector size)
15 * partition 2: the rest
16 */
17#define P0_SIZE (128 * 1024)
18#define P1_SIZE (4 * 1024)
19#define P1_START P0_SIZE
20#define P2_START (P0_SIZE + P1_SIZE)
21
22/* controller page size, in bytes */
23#define EP_PAGE_SIZE 256
24#define EP_PAGE_MASK (EP_PAGE_SIZE - 1)
25#define EP_PAGE_DWORDS (EP_PAGE_SIZE / sizeof(u32))
26
27/* controller commands */
28#define CMD_SHIFT 24
29#define CMD_NOP (0)
30#define CMD_READ_DATA(addr) ((0x03 << CMD_SHIFT) | addr)
31#define CMD_RELEASE_POWERDOWN_NOID ((0xab << CMD_SHIFT))
32
33/* controller interface speeds */
34#define EP_SPEED_FULL 0x2 /* full speed */
35
36/*
37 * How long to wait for the EPROM to become available, in ms.
38 * The spec 32 Mb EPROM takes around 40s to erase then write.
39 * Double it for safety.
40 */
41#define EPROM_TIMEOUT 80000 /* ms */
42
43/*
44 * Read a 256 byte (64 dword) EPROM page.
45 * All callers have verified the offset is at a page boundary.
46 */
47static void read_page(struct hfi1_devdata *dd, u32 offset, u32 *result)
48{
49 int i;
50
51 write_csr(dd, ASIC_EEP_ADDR_CMD, CMD_READ_DATA(offset));
52 for (i = 0; i < EP_PAGE_DWORDS; i++)
53 result[i] = (u32)read_csr(dd, ASIC_EEP_DATA);
54 write_csr(dd, ASIC_EEP_ADDR_CMD, CMD_NOP); /* close open page */
55}
56
57/*
58 * Read length bytes starting at offset from the start of the EPROM.
59 */
60static int read_length(struct hfi1_devdata *dd, u32 start, u32 len, void *dest)
61{
62 u32 buffer[EP_PAGE_DWORDS];
63 u32 end;
64 u32 start_offset;
65 u32 read_start;
66 u32 bytes;
67
68 if (len == 0)
69 return 0;
70
71 end = start + len;
72
73 /*
74 * Make sure the read range is not outside of the controller read
75 * command address range. Note that '>' is correct below - the end
76 * of the range is OK if it stops at the limit, but no higher.
77 */
78 if (end > (1 << CMD_SHIFT))
79 return -EINVAL;
80
81 /* read the first partial page */
82 start_offset = start & EP_PAGE_MASK;
83 if (start_offset) {
84 /* partial starting page */
85
86 /* align and read the page that contains the start */
87 read_start = start & ~EP_PAGE_MASK;
88 read_page(dd, offset: read_start, result: buffer);
89
90 /* the rest of the page is available data */
91 bytes = EP_PAGE_SIZE - start_offset;
92
93 if (len <= bytes) {
94 /* end is within this page */
95 memcpy(dest, (u8 *)buffer + start_offset, len);
96 return 0;
97 }
98
99 memcpy(dest, (u8 *)buffer + start_offset, bytes);
100
101 start += bytes;
102 len -= bytes;
103 dest += bytes;
104 }
105 /* start is now page aligned */
106
107 /* read whole pages */
108 while (len >= EP_PAGE_SIZE) {
109 read_page(dd, offset: start, result: buffer);
110 memcpy(dest, buffer, EP_PAGE_SIZE);
111
112 start += EP_PAGE_SIZE;
113 len -= EP_PAGE_SIZE;
114 dest += EP_PAGE_SIZE;
115 }
116
117 /* read the last partial page */
118 if (len) {
119 read_page(dd, offset: start, result: buffer);
120 memcpy(dest, buffer, len);
121 }
122
123 return 0;
124}
125
126/*
127 * Initialize the EPROM handler.
128 */
129int eprom_init(struct hfi1_devdata *dd)
130{
131 int ret = 0;
132
133 /* only the discrete chip has an EPROM */
134 if (dd->pcidev->device != PCI_DEVICE_ID_INTEL0)
135 return 0;
136
137 /*
138 * It is OK if both HFIs reset the EPROM as long as they don't
139 * do it at the same time.
140 */
141 ret = acquire_chip_resource(dd, CR_EPROM, EPROM_TIMEOUT);
142 if (ret) {
143 dd_dev_err(dd,
144 "%s: unable to acquire EPROM resource, no EPROM support\n",
145 __func__);
146 goto done_asic;
147 }
148
149 /* reset EPROM to be sure it is in a good state */
150
151 /* set reset */
152 write_csr(dd, ASIC_EEP_CTL_STAT, ASIC_EEP_CTL_STAT_EP_RESET_SMASK);
153 /* clear reset, set speed */
154 write_csr(dd, ASIC_EEP_CTL_STAT,
155 EP_SPEED_FULL << ASIC_EEP_CTL_STAT_RATE_SPI_SHIFT);
156
157 /* wake the device with command "release powerdown NoID" */
158 write_csr(dd, ASIC_EEP_ADDR_CMD, CMD_RELEASE_POWERDOWN_NOID);
159
160 dd->eprom_available = true;
161 release_chip_resource(dd, CR_EPROM);
162done_asic:
163 return ret;
164}
165
166/* magic character sequence that begins an image */
167#define IMAGE_START_MAGIC "APO="
168
169/* magic character sequence that might trail an image */
170#define IMAGE_TRAIL_MAGIC "egamiAPO"
171
172/* EPROM file types */
173#define HFI1_EFT_PLATFORM_CONFIG 2
174
175/* segment size - 128 KiB */
176#define SEG_SIZE (128 * 1024)
177
178struct hfi1_eprom_footer {
179 u32 oprom_size; /* size of the oprom, in bytes */
180 u16 num_table_entries;
181 u16 version; /* version of this footer */
182 u32 magic; /* must be last */
183};
184
185struct hfi1_eprom_table_entry {
186 u32 type; /* file type */
187 u32 offset; /* file offset from start of EPROM */
188 u32 size; /* file size, in bytes */
189};
190
191/*
192 * Calculate the max number of table entries that will fit within a directory
193 * buffer of size 'dir_size'.
194 */
195#define MAX_TABLE_ENTRIES(dir_size) \
196 (((dir_size) - sizeof(struct hfi1_eprom_footer)) / \
197 sizeof(struct hfi1_eprom_table_entry))
198
199#define DIRECTORY_SIZE(n) (sizeof(struct hfi1_eprom_footer) + \
200 (sizeof(struct hfi1_eprom_table_entry) * (n)))
201
202#define MAGIC4(a, b, c, d) ((d) << 24 | (c) << 16 | (b) << 8 | (a))
203#define FOOTER_MAGIC MAGIC4('e', 'p', 'r', 'm')
204#define FOOTER_VERSION 1
205
206/*
207 * Read all of partition 1. The actual file is at the front. Adjust
208 * the returned size if a trailing image magic is found.
209 */
210static int read_partition_platform_config(struct hfi1_devdata *dd, void **data,
211 u32 *size)
212{
213 void *buffer;
214 void *p;
215 u32 length;
216 int ret;
217
218 buffer = kmalloc(P1_SIZE, GFP_KERNEL);
219 if (!buffer)
220 return -ENOMEM;
221
222 ret = read_length(dd, P1_START, P1_SIZE, dest: buffer);
223 if (ret) {
224 kfree(objp: buffer);
225 return ret;
226 }
227
228 /* config partition is valid only if it starts with IMAGE_START_MAGIC */
229 if (memcmp(p: buffer, IMAGE_START_MAGIC, strlen(IMAGE_START_MAGIC))) {
230 kfree(objp: buffer);
231 return -ENOENT;
232 }
233
234 /* scan for image magic that may trail the actual data */
235 p = strnstr(buffer, IMAGE_TRAIL_MAGIC, P1_SIZE);
236 if (p)
237 length = p - buffer;
238 else
239 length = P1_SIZE;
240
241 *data = buffer;
242 *size = length;
243 return 0;
244}
245
246/*
247 * The segment magic has been checked. There is a footer and table of
248 * contents present.
249 *
250 * directory is a u32 aligned buffer of size EP_PAGE_SIZE.
251 */
252static int read_segment_platform_config(struct hfi1_devdata *dd,
253 void *directory, void **data, u32 *size)
254{
255 struct hfi1_eprom_footer *footer;
256 struct hfi1_eprom_table_entry *table;
257 struct hfi1_eprom_table_entry *entry;
258 void *buffer = NULL;
259 void *table_buffer = NULL;
260 int ret, i;
261 u32 directory_size;
262 u32 seg_base, seg_offset;
263 u32 bytes_available, ncopied, to_copy;
264
265 /* the footer is at the end of the directory */
266 footer = (struct hfi1_eprom_footer *)
267 (directory + EP_PAGE_SIZE - sizeof(*footer));
268
269 /* make sure the structure version is supported */
270 if (footer->version != FOOTER_VERSION)
271 return -EINVAL;
272
273 /* oprom size cannot be larger than a segment */
274 if (footer->oprom_size >= SEG_SIZE)
275 return -EINVAL;
276
277 /* the file table must fit in a segment with the oprom */
278 if (footer->num_table_entries >
279 MAX_TABLE_ENTRIES(SEG_SIZE - footer->oprom_size))
280 return -EINVAL;
281
282 /* find the file table start, which precedes the footer */
283 directory_size = DIRECTORY_SIZE(footer->num_table_entries);
284 if (directory_size <= EP_PAGE_SIZE) {
285 /* the file table fits into the directory buffer handed in */
286 table = (struct hfi1_eprom_table_entry *)
287 (directory + EP_PAGE_SIZE - directory_size);
288 } else {
289 /* need to allocate and read more */
290 table_buffer = kmalloc(size: directory_size, GFP_KERNEL);
291 if (!table_buffer)
292 return -ENOMEM;
293 ret = read_length(dd, SEG_SIZE - directory_size,
294 len: directory_size, dest: table_buffer);
295 if (ret)
296 goto done;
297 table = table_buffer;
298 }
299
300 /* look for the platform configuration file in the table */
301 for (entry = NULL, i = 0; i < footer->num_table_entries; i++) {
302 if (table[i].type == HFI1_EFT_PLATFORM_CONFIG) {
303 entry = &table[i];
304 break;
305 }
306 }
307 if (!entry) {
308 ret = -ENOENT;
309 goto done;
310 }
311
312 /*
313 * Sanity check on the configuration file size - it should never
314 * be larger than 4 KiB.
315 */
316 if (entry->size > (4 * 1024)) {
317 dd_dev_err(dd, "Bad configuration file size 0x%x\n",
318 entry->size);
319 ret = -EINVAL;
320 goto done;
321 }
322
323 /* check for bogus offset and size that wrap when added together */
324 if (entry->offset + entry->size < entry->offset) {
325 dd_dev_err(dd,
326 "Bad configuration file start + size 0x%x+0x%x\n",
327 entry->offset, entry->size);
328 ret = -EINVAL;
329 goto done;
330 }
331
332 /* allocate the buffer to return */
333 buffer = kmalloc(size: entry->size, GFP_KERNEL);
334 if (!buffer) {
335 ret = -ENOMEM;
336 goto done;
337 }
338
339 /*
340 * Extract the file by looping over segments until it is fully read.
341 */
342 seg_offset = entry->offset % SEG_SIZE;
343 seg_base = entry->offset - seg_offset;
344 ncopied = 0;
345 while (ncopied < entry->size) {
346 /* calculate data bytes available in this segment */
347
348 /* start with the bytes from the current offset to the end */
349 bytes_available = SEG_SIZE - seg_offset;
350 /* subtract off footer and table from segment 0 */
351 if (seg_base == 0) {
352 /*
353 * Sanity check: should not have a starting point
354 * at or within the directory.
355 */
356 if (bytes_available <= directory_size) {
357 dd_dev_err(dd,
358 "Bad configuration file - offset 0x%x within footer+table\n",
359 entry->offset);
360 ret = -EINVAL;
361 goto done;
362 }
363 bytes_available -= directory_size;
364 }
365
366 /* calculate bytes wanted */
367 to_copy = entry->size - ncopied;
368
369 /* max out at the available bytes in this segment */
370 if (to_copy > bytes_available)
371 to_copy = bytes_available;
372
373 /*
374 * Read from the EPROM.
375 *
376 * The sanity check for entry->offset is done in read_length().
377 * The EPROM offset is validated against what the hardware
378 * addressing supports. In addition, if the offset is larger
379 * than the actual EPROM, it silently wraps. It will work
380 * fine, though the reader may not get what they expected
381 * from the EPROM.
382 */
383 ret = read_length(dd, start: seg_base + seg_offset, len: to_copy,
384 dest: buffer + ncopied);
385 if (ret)
386 goto done;
387
388 ncopied += to_copy;
389
390 /* set up for next segment */
391 seg_offset = footer->oprom_size;
392 seg_base += SEG_SIZE;
393 }
394
395 /* success */
396 ret = 0;
397 *data = buffer;
398 *size = entry->size;
399
400done:
401 kfree(objp: table_buffer);
402 if (ret)
403 kfree(objp: buffer);
404 return ret;
405}
406
407/*
408 * Read the platform configuration file from the EPROM.
409 *
410 * On success, an allocated buffer containing the data and its size are
411 * returned. It is up to the caller to free this buffer.
412 *
413 * Return value:
414 * 0 - success
415 * -ENXIO - no EPROM is available
416 * -EBUSY - not able to acquire access to the EPROM
417 * -ENOENT - no recognizable file written
418 * -ENOMEM - buffer could not be allocated
419 * -EINVAL - invalid EPROM contentents found
420 */
421int eprom_read_platform_config(struct hfi1_devdata *dd, void **data, u32 *size)
422{
423 u32 directory[EP_PAGE_DWORDS]; /* aligned buffer */
424 int ret;
425
426 if (!dd->eprom_available)
427 return -ENXIO;
428
429 ret = acquire_chip_resource(dd, CR_EPROM, EPROM_TIMEOUT);
430 if (ret)
431 return -EBUSY;
432
433 /* read the last page of the segment for the EPROM format magic */
434 ret = read_length(dd, SEG_SIZE - EP_PAGE_SIZE, EP_PAGE_SIZE, dest: directory);
435 if (ret)
436 goto done;
437
438 /* last dword of the segment contains a magic value */
439 if (directory[EP_PAGE_DWORDS - 1] == FOOTER_MAGIC) {
440 /* segment format */
441 ret = read_segment_platform_config(dd, directory, data, size);
442 } else {
443 /* partition format */
444 ret = read_partition_platform_config(dd, data, size);
445 }
446
447done:
448 release_chip_resource(dd, CR_EPROM);
449 return ret;
450}
451

source code of linux/drivers/infiniband/hw/hfi1/eprom.c