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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
4 * Volker Sameske <sameske@de.ibm.com>
5 * Bugreports.to..: <Linux390@de.ibm.com>
6 * Copyright IBM Corp. 1999, 2012
7 */
8
9#include <linux/buffer_head.h>
10#include <linux/hdreg.h>
11#include <linux/slab.h>
12#include <asm/dasd.h>
13#include <asm/ebcdic.h>
14#include <linux/uaccess.h>
15#include <asm/vtoc.h>
16#include <linux/module.h>
17#include <linux/dasd_mod.h>
18
19#include "check.h"
20
21union label_t {
22 struct vtoc_volume_label_cdl vol;
23 struct vtoc_volume_label_ldl lnx;
24 struct vtoc_cms_label cms;
25};
26
27/*
28 * compute the block number from a
29 * cyl-cyl-head-head structure
30 */
31static sector_t cchh2blk(struct vtoc_cchh *ptr, struct hd_geometry *geo)
32{
33 sector_t cyl;
34 __u16 head;
35
36 /* decode cylinder and heads for large volumes */
37 cyl = ptr->hh & 0xFFF0;
38 cyl <<= 12;
39 cyl |= ptr->cc;
40 head = ptr->hh & 0x000F;
41 return cyl * geo->heads * geo->sectors +
42 head * geo->sectors;
43}
44
45/*
46 * compute the block number from a
47 * cyl-cyl-head-head-block structure
48 */
49static sector_t cchhb2blk(struct vtoc_cchhb *ptr, struct hd_geometry *geo)
50{
51 sector_t cyl;
52 __u16 head;
53
54 /* decode cylinder and heads for large volumes */
55 cyl = ptr->hh & 0xFFF0;
56 cyl <<= 12;
57 cyl |= ptr->cc;
58 head = ptr->hh & 0x000F;
59 return cyl * geo->heads * geo->sectors +
60 head * geo->sectors +
61 ptr->b;
62}
63
64/* Volume Label Type/ID Length */
65#define DASD_VOL_TYPE_LEN 4
66#define DASD_VOL_ID_LEN 6
67
68/* Volume Label Types */
69#define DASD_VOLLBL_TYPE_VOL1 0
70#define DASD_VOLLBL_TYPE_LNX1 1
71#define DASD_VOLLBL_TYPE_CMS1 2
72
73struct dasd_vollabel {
74 char *type;
75 int idx;
76};
77
78static struct dasd_vollabel dasd_vollabels[] = {
79 [DASD_VOLLBL_TYPE_VOL1] = {
80 .type = "VOL1",
81 .idx = DASD_VOLLBL_TYPE_VOL1,
82 },
83 [DASD_VOLLBL_TYPE_LNX1] = {
84 .type = "LNX1",
85 .idx = DASD_VOLLBL_TYPE_LNX1,
86 },
87 [DASD_VOLLBL_TYPE_CMS1] = {
88 .type = "CMS1",
89 .idx = DASD_VOLLBL_TYPE_CMS1,
90 },
91};
92
93static int get_label_by_type(const char *type)
94{
95 int i;
96
97 for (i = 0; i < ARRAY_SIZE(dasd_vollabels); i++) {
98 if (!memcmp(p: type, q: dasd_vollabels[i].type, DASD_VOL_TYPE_LEN))
99 return dasd_vollabels[i].idx;
100 }
101
102 return -1;
103}
104
105static int find_label(struct parsed_partitions *state,
106 dasd_information2_t *info,
107 struct hd_geometry *geo,
108 int blocksize,
109 sector_t *labelsect,
110 char name[],
111 char type[],
112 union label_t *label)
113{
114 sector_t testsect[3];
115 int i, testcount;
116 Sector sect;
117 void *data;
118
119 /* There a three places where we may find a valid label:
120 * - on an ECKD disk it's block 2
121 * - on an FBA disk it's block 1
122 * - on an CMS formatted FBA disk it is sector 1, even if the block size
123 * is larger than 512 bytes (possible if the DIAG discipline is used)
124 * If we have a valid info structure, then we know exactly which case we
125 * have, otherwise we just search through all possebilities.
126 */
127 if (info) {
128 if ((info->cu_type == 0x6310 && info->dev_type == 0x9336) ||
129 (info->cu_type == 0x3880 && info->dev_type == 0x3370))
130 testsect[0] = info->label_block;
131 else
132 testsect[0] = info->label_block * (blocksize >> 9);
133 testcount = 1;
134 } else {
135 testsect[0] = 1;
136 testsect[1] = (blocksize >> 9);
137 testsect[2] = 2 * (blocksize >> 9);
138 testcount = 3;
139 }
140 for (i = 0; i < testcount; ++i) {
141 data = read_part_sector(state, n: testsect[i], p: &sect);
142 if (data == NULL)
143 continue;
144 memcpy(label, data, sizeof(*label));
145 memcpy(type, data, DASD_VOL_TYPE_LEN);
146 EBCASC(type, DASD_VOL_TYPE_LEN);
147 put_dev_sector(p: sect);
148 switch (get_label_by_type(type)) {
149 case DASD_VOLLBL_TYPE_VOL1:
150 memcpy(name, label->vol.volid, DASD_VOL_ID_LEN);
151 EBCASC(name, DASD_VOL_ID_LEN);
152 *labelsect = testsect[i];
153 return 1;
154 case DASD_VOLLBL_TYPE_LNX1:
155 case DASD_VOLLBL_TYPE_CMS1:
156 memcpy(name, label->lnx.volid, DASD_VOL_ID_LEN);
157 EBCASC(name, DASD_VOL_ID_LEN);
158 *labelsect = testsect[i];
159 return 1;
160 default:
161 break;
162 }
163 }
164
165 return 0;
166}
167
168static int find_vol1_partitions(struct parsed_partitions *state,
169 struct hd_geometry *geo,
170 int blocksize,
171 char name[],
172 union label_t *label)
173{
174 sector_t blk;
175 int counter;
176 char tmp[64];
177 Sector sect;
178 unsigned char *data;
179 loff_t offset, size;
180 struct vtoc_format1_label f1;
181 int secperblk;
182
183 snprintf(buf: tmp, size: sizeof(tmp), fmt: "VOL1/%8s:", name);
184 strlcat(p: state->pp_buf, q: tmp, PAGE_SIZE);
185 /*
186 * get start of VTOC from the disk label and then search for format1
187 * and format8 labels
188 */
189 secperblk = blocksize >> 9;
190 blk = cchhb2blk(ptr: &label->vol.vtoc, geo) + 1;
191 counter = 0;
192 data = read_part_sector(state, n: blk * secperblk, p: &sect);
193 while (data != NULL) {
194 memcpy(&f1, data, sizeof(struct vtoc_format1_label));
195 put_dev_sector(p: sect);
196 /* skip FMT4 / FMT5 / FMT7 labels */
197 if (f1.DS1FMTID == _ascebc['4']
198 || f1.DS1FMTID == _ascebc['5']
199 || f1.DS1FMTID == _ascebc['7']
200 || f1.DS1FMTID == _ascebc['9']) {
201 blk++;
202 data = read_part_sector(state, n: blk * secperblk, p: &sect);
203 continue;
204 }
205 /* only FMT1 and 8 labels valid at this point */
206 if (f1.DS1FMTID != _ascebc['1'] &&
207 f1.DS1FMTID != _ascebc['8'])
208 break;
209 /* OK, we got valid partition data */
210 offset = cchh2blk(ptr: &f1.DS1EXT1.llimit, geo);
211 size = cchh2blk(ptr: &f1.DS1EXT1.ulimit, geo) -
212 offset + geo->sectors;
213 offset *= secperblk;
214 size *= secperblk;
215 if (counter >= state->limit)
216 break;
217 put_partition(p: state, n: counter + 1, from: offset, size);
218 counter++;
219 blk++;
220 data = read_part_sector(state, n: blk * secperblk, p: &sect);
221 }
222 strlcat(p: state->pp_buf, q: "\n", PAGE_SIZE);
223
224 if (!data)
225 return -1;
226
227 return 1;
228}
229
230static int find_lnx1_partitions(struct parsed_partitions *state,
231 struct hd_geometry *geo,
232 int blocksize,
233 char name[],
234 union label_t *label,
235 sector_t labelsect,
236 sector_t nr_sectors,
237 dasd_information2_t *info)
238{
239 loff_t offset, geo_size, size;
240 char tmp[64];
241 int secperblk;
242
243 snprintf(buf: tmp, size: sizeof(tmp), fmt: "LNX1/%8s:", name);
244 strlcat(p: state->pp_buf, q: tmp, PAGE_SIZE);
245 secperblk = blocksize >> 9;
246 if (label->lnx.ldl_version == 0xf2) {
247 size = label->lnx.formatted_blocks * secperblk;
248 } else {
249 /*
250 * Formated w/o large volume support. If the sanity check
251 * 'size based on geo == size based on nr_sectors' is true, then
252 * we can safely assume that we know the formatted size of
253 * the disk, otherwise we need additional information
254 * that we can only get from a real DASD device.
255 */
256 geo_size = geo->cylinders * geo->heads
257 * geo->sectors * secperblk;
258 size = nr_sectors;
259 if (size != geo_size) {
260 if (!info) {
261 strlcat(p: state->pp_buf, q: "\n", PAGE_SIZE);
262 return 1;
263 }
264 if (!strcmp(info->type, "ECKD"))
265 if (geo_size < size)
266 size = geo_size;
267 /* else keep size based on nr_sectors */
268 }
269 }
270 /* first and only partition starts in the first block after the label */
271 offset = labelsect + secperblk;
272 put_partition(p: state, n: 1, from: offset, size: size - offset);
273 strlcat(p: state->pp_buf, q: "\n", PAGE_SIZE);
274 return 1;
275}
276
277static int find_cms1_partitions(struct parsed_partitions *state,
278 struct hd_geometry *geo,
279 int blocksize,
280 char name[],
281 union label_t *label,
282 sector_t labelsect)
283{
284 loff_t offset, size;
285 char tmp[64];
286 int secperblk;
287
288 /*
289 * VM style CMS1 labeled disk
290 */
291 blocksize = label->cms.block_size;
292 secperblk = blocksize >> 9;
293 if (label->cms.disk_offset != 0) {
294 snprintf(buf: tmp, size: sizeof(tmp), fmt: "CMS1/%8s(MDSK):", name);
295 strlcat(p: state->pp_buf, q: tmp, PAGE_SIZE);
296 /* disk is reserved minidisk */
297 offset = label->cms.disk_offset * secperblk;
298 size = (label->cms.block_count - 1) * secperblk;
299 } else {
300 snprintf(buf: tmp, size: sizeof(tmp), fmt: "CMS1/%8s:", name);
301 strlcat(p: state->pp_buf, q: tmp, PAGE_SIZE);
302 /*
303 * Special case for FBA devices:
304 * If an FBA device is CMS formatted with blocksize > 512 byte
305 * and the DIAG discipline is used, then the CMS label is found
306 * in sector 1 instead of block 1. However, the partition is
307 * still supposed to start in block 2.
308 */
309 if (labelsect == 1)
310 offset = 2 * secperblk;
311 else
312 offset = labelsect + secperblk;
313 size = label->cms.block_count * secperblk;
314 }
315
316 put_partition(p: state, n: 1, from: offset, size: size-offset);
317 strlcat(p: state->pp_buf, q: "\n", PAGE_SIZE);
318 return 1;
319}
320
321
322/*
323 * This is the main function, called by check.c
324 */
325int ibm_partition(struct parsed_partitions *state)
326{
327 int (*fn)(struct gendisk *disk, dasd_information2_t *info);
328 struct gendisk *disk = state->disk;
329 struct block_device *bdev = disk->part0;
330 int blocksize, res;
331 loff_t offset, size;
332 sector_t nr_sectors;
333 dasd_information2_t *info;
334 struct hd_geometry *geo;
335 char type[DASD_VOL_TYPE_LEN + 1] = "";
336 char name[DASD_VOL_ID_LEN + 1] = "";
337 sector_t labelsect;
338 union label_t *label;
339
340 res = 0;
341 if (!disk->fops->getgeo)
342 goto out_exit;
343 fn = symbol_get(dasd_biodasdinfo);
344 blocksize = bdev_logical_block_size(bdev);
345 if (blocksize <= 0)
346 goto out_symbol;
347 nr_sectors = bdev_nr_sectors(bdev);
348 if (nr_sectors == 0)
349 goto out_symbol;
350 info = kmalloc(sizeof(dasd_information2_t), GFP_KERNEL);
351 if (info == NULL)
352 goto out_symbol;
353 geo = kmalloc(sizeof(struct hd_geometry), GFP_KERNEL);
354 if (geo == NULL)
355 goto out_nogeo;
356 label = kmalloc(sizeof(union label_t), GFP_KERNEL);
357 if (label == NULL)
358 goto out_nolab;
359 /* set start if not filled by getgeo function e.g. virtblk */
360 geo->start = get_start_sect(bdev);
361 if (disk->fops->getgeo(disk, geo))
362 goto out_freeall;
363 if (!fn || fn(disk, info)) {
364 kfree(objp: info);
365 info = NULL;
366 }
367
368 if (find_label(state, info, geo, blocksize, &labelsect, name, type, label)) {
369 switch (get_label_by_type(type)) {
370 case DASD_VOLLBL_TYPE_VOL1:
371 res = find_vol1_partitions(state, geo, blocksize, name,
372 label);
373 break;
374 case DASD_VOLLBL_TYPE_LNX1:
375 res = find_lnx1_partitions(state, geo, blocksize, name,
376 label, labelsect, nr_sectors,
377 info);
378 break;
379 case DASD_VOLLBL_TYPE_CMS1:
380 res = find_cms1_partitions(state, geo, blocksize, name,
381 label, labelsect);
382 break;
383 }
384 } else if (info) {
385 /*
386 * ugly but needed for backward compatibility:
387 * If the block device is a DASD (i.e. BIODASDINFO2 works),
388 * then we claim it in any case, even though it has no valid
389 * label. If it has the LDL format, then we simply define a
390 * partition as if it had an LNX1 label.
391 */
392 res = 1;
393 if (info->format == DASD_FORMAT_LDL) {
394 strlcat(p: state->pp_buf, q: "(nonl)", PAGE_SIZE);
395 size = nr_sectors;
396 offset = (info->label_block + 1) * (blocksize >> 9);
397 put_partition(p: state, n: 1, from: offset, size: size-offset);
398 strlcat(p: state->pp_buf, q: "\n", PAGE_SIZE);
399 }
400 } else
401 res = 0;
402
403out_freeall:
404 kfree(objp: label);
405out_nolab:
406 kfree(objp: geo);
407out_nogeo:
408 kfree(objp: info);
409out_symbol:
410 if (fn)
411 symbol_put(dasd_biodasdinfo);
412out_exit:
413 return res;
414}
415

source code of linux/block/partitions/ibm.c