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
20union 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 */
30static 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 */
48static 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
63static 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
132static 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
194static 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
241static 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 */
289int 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
356out_freeall:
357	kfree(label);
358out_nolab:
359	kfree(geo);
360out_nogeo:
361	kfree(info);
362out_exit:
363	return res;
364}
365