xref: /openbmc/linux/block/partitions/ibm.c (revision 9cfc5c90)
1 /*
2  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
3  *                  Volker Sameske <sameske@de.ibm.com>
4  * Bugreports.to..: <Linux390@de.ibm.com>
5  * Copyright IBM Corp. 1999, 2012
6  */
7 
8 #include <linux/buffer_head.h>
9 #include <linux/hdreg.h>
10 #include <linux/slab.h>
11 #include <asm/dasd.h>
12 #include <asm/ebcdic.h>
13 #include <asm/uaccess.h>
14 #include <asm/vtoc.h>
15 
16 #include "check.h"
17 #include "ibm.h"
18 
19 
20 union label_t {
21 	struct vtoc_volume_label_cdl vol;
22 	struct vtoc_volume_label_ldl lnx;
23 	struct vtoc_cms_label cms;
24 };
25 
26 /*
27  * compute the block number from a
28  * cyl-cyl-head-head structure
29  */
30 static sector_t cchh2blk(struct vtoc_cchh *ptr, struct hd_geometry *geo)
31 {
32 	sector_t cyl;
33 	__u16 head;
34 
35 	/* decode cylinder and heads for large volumes */
36 	cyl = ptr->hh & 0xFFF0;
37 	cyl <<= 12;
38 	cyl |= ptr->cc;
39 	head = ptr->hh & 0x000F;
40 	return cyl * geo->heads * geo->sectors +
41 	       head * geo->sectors;
42 }
43 
44 /*
45  * compute the block number from a
46  * cyl-cyl-head-head-block structure
47  */
48 static sector_t cchhb2blk(struct vtoc_cchhb *ptr, struct hd_geometry *geo)
49 {
50 	sector_t cyl;
51 	__u16 head;
52 
53 	/* decode cylinder and heads for large volumes */
54 	cyl = ptr->hh & 0xFFF0;
55 	cyl <<= 12;
56 	cyl |= ptr->cc;
57 	head = ptr->hh & 0x000F;
58 	return	cyl * geo->heads * geo->sectors +
59 		head * geo->sectors +
60 		ptr->b;
61 }
62 
63 static int find_label(struct parsed_partitions *state,
64 		      dasd_information2_t *info,
65 		      struct hd_geometry *geo,
66 		      int blocksize,
67 		      sector_t *labelsect,
68 		      char name[],
69 		      char type[],
70 		      union label_t *label)
71 {
72 	Sector sect;
73 	unsigned char *data;
74 	sector_t testsect[3];
75 	unsigned char temp[5];
76 	int found = 0;
77 	int i, testcount;
78 
79 	/* There a three places where we may find a valid label:
80 	 * - on an ECKD disk it's block 2
81 	 * - on an FBA disk it's block 1
82 	 * - on an CMS formatted FBA disk it is sector 1, even if the block size
83 	 *   is larger than 512 bytes (possible if the DIAG discipline is used)
84 	 * If we have a valid info structure, then we know exactly which case we
85 	 * have, otherwise we just search through all possebilities.
86 	 */
87 	if (info) {
88 		if ((info->cu_type == 0x6310 && info->dev_type == 0x9336) ||
89 		    (info->cu_type == 0x3880 && info->dev_type == 0x3370))
90 			testsect[0] = info->label_block;
91 		else
92 			testsect[0] = info->label_block * (blocksize >> 9);
93 		testcount = 1;
94 	} else {
95 		testsect[0] = 1;
96 		testsect[1] = (blocksize >> 9);
97 		testsect[2] = 2 * (blocksize >> 9);
98 		testcount = 3;
99 	}
100 	for (i = 0; i < testcount; ++i) {
101 		data = read_part_sector(state, testsect[i], &sect);
102 		if (data == NULL)
103 			continue;
104 		memcpy(label, data, sizeof(*label));
105 		memcpy(temp, data, 4);
106 		temp[4] = 0;
107 		EBCASC(temp, 4);
108 		put_dev_sector(sect);
109 		if (!strcmp(temp, "VOL1") ||
110 		    !strcmp(temp, "LNX1") ||
111 		    !strcmp(temp, "CMS1")) {
112 			if (!strcmp(temp, "VOL1")) {
113 				strncpy(type, label->vol.vollbl, 4);
114 				strncpy(name, label->vol.volid, 6);
115 			} else {
116 				strncpy(type, label->lnx.vollbl, 4);
117 				strncpy(name, label->lnx.volid, 6);
118 			}
119 			EBCASC(type, 4);
120 			EBCASC(name, 6);
121 			*labelsect = testsect[i];
122 			found = 1;
123 			break;
124 		}
125 	}
126 	if (!found)
127 		memset(label, 0, sizeof(*label));
128 
129 	return found;
130 }
131 
132 static int find_vol1_partitions(struct parsed_partitions *state,
133 				struct hd_geometry *geo,
134 				int blocksize,
135 				char name[],
136 				union label_t *label)
137 {
138 	sector_t blk;
139 	int counter;
140 	char tmp[64];
141 	Sector sect;
142 	unsigned char *data;
143 	loff_t offset, size;
144 	struct vtoc_format1_label f1;
145 	int secperblk;
146 
147 	snprintf(tmp, sizeof(tmp), "VOL1/%8s:", name);
148 	strlcat(state->pp_buf, tmp, PAGE_SIZE);
149 	/*
150 	 * get start of VTOC from the disk label and then search for format1
151 	 * and format8 labels
152 	 */
153 	secperblk = blocksize >> 9;
154 	blk = cchhb2blk(&label->vol.vtoc, geo) + 1;
155 	counter = 0;
156 	data = read_part_sector(state, blk * secperblk, &sect);
157 	while (data != NULL) {
158 		memcpy(&f1, data, sizeof(struct vtoc_format1_label));
159 		put_dev_sector(sect);
160 		/* skip FMT4 / FMT5 / FMT7 labels */
161 		if (f1.DS1FMTID == _ascebc['4']
162 		    || f1.DS1FMTID == _ascebc['5']
163 		    || f1.DS1FMTID == _ascebc['7']
164 		    || f1.DS1FMTID == _ascebc['9']) {
165 			blk++;
166 			data = read_part_sector(state, blk * secperblk, &sect);
167 			continue;
168 		}
169 		/* only FMT1 and 8 labels valid at this point */
170 		if (f1.DS1FMTID != _ascebc['1'] &&
171 		    f1.DS1FMTID != _ascebc['8'])
172 			break;
173 		/* OK, we got valid partition data */
174 		offset = cchh2blk(&f1.DS1EXT1.llimit, geo);
175 		size  = cchh2blk(&f1.DS1EXT1.ulimit, geo) -
176 			offset + geo->sectors;
177 		offset *= secperblk;
178 		size *= secperblk;
179 		if (counter >= state->limit)
180 			break;
181 		put_partition(state, counter + 1, offset, size);
182 		counter++;
183 		blk++;
184 		data = read_part_sector(state, blk * secperblk, &sect);
185 	}
186 	strlcat(state->pp_buf, "\n", PAGE_SIZE);
187 
188 	if (!data)
189 		return -1;
190 
191 	return 1;
192 }
193 
194 static int find_lnx1_partitions(struct parsed_partitions *state,
195 				struct hd_geometry *geo,
196 				int blocksize,
197 				char name[],
198 				union label_t *label,
199 				sector_t labelsect,
200 				loff_t i_size,
201 				dasd_information2_t *info)
202 {
203 	loff_t offset, geo_size, size;
204 	char tmp[64];
205 	int secperblk;
206 
207 	snprintf(tmp, sizeof(tmp), "LNX1/%8s:", name);
208 	strlcat(state->pp_buf, tmp, PAGE_SIZE);
209 	secperblk = blocksize >> 9;
210 	if (label->lnx.ldl_version == 0xf2) {
211 		size = label->lnx.formatted_blocks * secperblk;
212 	} else {
213 		/*
214 		 * Formated w/o large volume support. If the sanity check
215 		 * 'size based on geo == size based on i_size' is true, then
216 		 * we can safely assume that we know the formatted size of
217 		 * the disk, otherwise we need additional information
218 		 * that we can only get from a real DASD device.
219 		 */
220 		geo_size = geo->cylinders * geo->heads
221 			* geo->sectors * secperblk;
222 		size = i_size >> 9;
223 		if (size != geo_size) {
224 			if (!info) {
225 				strlcat(state->pp_buf, "\n", PAGE_SIZE);
226 				return 1;
227 			}
228 			if (!strcmp(info->type, "ECKD"))
229 				if (geo_size < size)
230 					size = geo_size;
231 			/* else keep size based on i_size */
232 		}
233 	}
234 	/* first and only partition starts in the first block after the label */
235 	offset = labelsect + secperblk;
236 	put_partition(state, 1, offset, size - offset);
237 	strlcat(state->pp_buf, "\n", PAGE_SIZE);
238 	return 1;
239 }
240 
241 static int find_cms1_partitions(struct parsed_partitions *state,
242 				struct hd_geometry *geo,
243 				int blocksize,
244 				char name[],
245 				union label_t *label,
246 				sector_t labelsect)
247 {
248 	loff_t offset, size;
249 	char tmp[64];
250 	int secperblk;
251 
252 	/*
253 	 * VM style CMS1 labeled disk
254 	 */
255 	blocksize = label->cms.block_size;
256 	secperblk = blocksize >> 9;
257 	if (label->cms.disk_offset != 0) {
258 		snprintf(tmp, sizeof(tmp), "CMS1/%8s(MDSK):", name);
259 		strlcat(state->pp_buf, tmp, PAGE_SIZE);
260 		/* disk is reserved minidisk */
261 		offset = label->cms.disk_offset * secperblk;
262 		size = (label->cms.block_count - 1) * secperblk;
263 	} else {
264 		snprintf(tmp, sizeof(tmp), "CMS1/%8s:", name);
265 		strlcat(state->pp_buf, tmp, PAGE_SIZE);
266 		/*
267 		 * Special case for FBA devices:
268 		 * If an FBA device is CMS formatted with blocksize > 512 byte
269 		 * and the DIAG discipline is used, then the CMS label is found
270 		 * in sector 1 instead of block 1. However, the partition is
271 		 * still supposed to start in block 2.
272 		 */
273 		if (labelsect == 1)
274 			offset = 2 * secperblk;
275 		else
276 			offset = labelsect + secperblk;
277 		size = label->cms.block_count * secperblk;
278 	}
279 
280 	put_partition(state, 1, offset, size-offset);
281 	strlcat(state->pp_buf, "\n", PAGE_SIZE);
282 	return 1;
283 }
284 
285 
286 /*
287  * This is the main function, called by check.c
288  */
289 int ibm_partition(struct parsed_partitions *state)
290 {
291 	struct block_device *bdev = state->bdev;
292 	int blocksize, res;
293 	loff_t i_size, offset, size;
294 	dasd_information2_t *info;
295 	struct hd_geometry *geo;
296 	char type[5] = {0,};
297 	char name[7] = {0,};
298 	sector_t labelsect;
299 	union label_t *label;
300 
301 	res = 0;
302 	blocksize = bdev_logical_block_size(bdev);
303 	if (blocksize <= 0)
304 		goto out_exit;
305 	i_size = i_size_read(bdev->bd_inode);
306 	if (i_size == 0)
307 		goto out_exit;
308 	info = kmalloc(sizeof(dasd_information2_t), GFP_KERNEL);
309 	if (info == NULL)
310 		goto out_exit;
311 	geo = kmalloc(sizeof(struct hd_geometry), GFP_KERNEL);
312 	if (geo == NULL)
313 		goto out_nogeo;
314 	label = kmalloc(sizeof(union label_t), GFP_KERNEL);
315 	if (label == NULL)
316 		goto out_nolab;
317 	if (ioctl_by_bdev(bdev, HDIO_GETGEO, (unsigned long)geo) != 0)
318 		goto out_freeall;
319 	if (ioctl_by_bdev(bdev, BIODASDINFO2, (unsigned long)info) != 0) {
320 		kfree(info);
321 		info = NULL;
322 	}
323 
324 	if (find_label(state, info, geo, blocksize, &labelsect, name, type,
325 		       label)) {
326 		if (!strncmp(type, "VOL1", 4)) {
327 			res = find_vol1_partitions(state, geo, blocksize, name,
328 						   label);
329 		} else if (!strncmp(type, "LNX1", 4)) {
330 			res = find_lnx1_partitions(state, geo, blocksize, name,
331 						   label, labelsect, i_size,
332 						   info);
333 		} else if (!strncmp(type, "CMS1", 4)) {
334 			res = find_cms1_partitions(state, geo, blocksize, name,
335 						   label, labelsect);
336 		}
337 	} else if (info) {
338 		/*
339 		 * ugly but needed for backward compatibility:
340 		 * If the block device is a DASD (i.e. BIODASDINFO2 works),
341 		 * then we claim it in any case, even though it has no valid
342 		 * label. If it has the LDL format, then we simply define a
343 		 * partition as if it had an LNX1 label.
344 		 */
345 		res = 1;
346 		if (info->format == DASD_FORMAT_LDL) {
347 			strlcat(state->pp_buf, "(nonl)", PAGE_SIZE);
348 			size = i_size >> 9;
349 			offset = (info->label_block + 1) * (blocksize >> 9);
350 			put_partition(state, 1, offset, size-offset);
351 			strlcat(state->pp_buf, "\n", PAGE_SIZE);
352 		}
353 	} else
354 		res = 0;
355 
356 out_freeall:
357 	kfree(label);
358 out_nolab:
359 	kfree(geo);
360 out_nogeo:
361 	kfree(info);
362 out_exit:
363 	return res;
364 }
365