1/*
2 * Copyright (C) 2000 Jens Axboe <axboe@suse.de>
3 * Copyright (C) 2001-2004 Peter Osterlund <petero2@telia.com>
4 * Copyright (C) 2006 Thomas Maier <balagi@justmail.de>
5 *
6 * May be copied or modified under the terms of the GNU General Public
7 * License.  See linux/COPYING for more information.
8 *
9 * Packet writing layer for ATAPI and SCSI CD-RW, DVD+RW, DVD-RW and
10 * DVD-RAM devices.
11 *
12 * Theory of operation:
13 *
14 * At the lowest level, there is the standard driver for the CD/DVD device,
15 * typically ide-cd.c or sr.c. This driver can handle read and write requests,
16 * but it doesn't know anything about the special restrictions that apply to
17 * packet writing. One restriction is that write requests must be aligned to
18 * packet boundaries on the physical media, and the size of a write request
19 * must be equal to the packet size. Another restriction is that a
20 * GPCMD_FLUSH_CACHE command has to be issued to the drive before a read
21 * command, if the previous command was a write.
22 *
23 * The purpose of the packet writing driver is to hide these restrictions from
24 * higher layers, such as file systems, and present a block device that can be
25 * randomly read and written using 2kB-sized blocks.
26 *
27 * The lowest layer in the packet writing driver is the packet I/O scheduler.
28 * Its data is defined by the struct packet_iosched and includes two bio
29 * queues with pending read and write requests. These queues are processed
30 * by the pkt_iosched_process_queue() function. The write requests in this
31 * queue are already properly aligned and sized. This layer is responsible for
32 * issuing the flush cache commands and scheduling the I/O in a good order.
33 *
34 * The next layer transforms unaligned write requests to aligned writes. This
35 * transformation requires reading missing pieces of data from the underlying
36 * block device, assembling the pieces to full packets and queuing them to the
37 * packet I/O scheduler.
38 *
39 * At the top layer there is a custom make_request_fn function that forwards
40 * read requests directly to the iosched queue and puts write requests in the
41 * unaligned write queue. A kernel thread performs the necessary read
42 * gathering to convert the unaligned writes to aligned writes and then feeds
43 * them to the packet I/O scheduler.
44 *
45 *************************************************************************/
46
47#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
48
49#include <linux/pktcdvd.h>
50#include <linux/module.h>
51#include <linux/types.h>
52#include <linux/kernel.h>
53#include <linux/compat.h>
54#include <linux/kthread.h>
55#include <linux/errno.h>
56#include <linux/spinlock.h>
57#include <linux/file.h>
58#include <linux/proc_fs.h>
59#include <linux/seq_file.h>
60#include <linux/miscdevice.h>
61#include <linux/freezer.h>
62#include <linux/mutex.h>
63#include <linux/slab.h>
64#include <linux/backing-dev.h>
65#include <scsi/scsi_cmnd.h>
66#include <scsi/scsi_ioctl.h>
67#include <scsi/scsi.h>
68#include <linux/debugfs.h>
69#include <linux/device.h>
70
71#include <asm/uaccess.h>
72
73#define DRIVER_NAME	"pktcdvd"
74
75#define pkt_err(pd, fmt, ...)						\
76	pr_err("%s: " fmt, pd->name, ##__VA_ARGS__)
77#define pkt_notice(pd, fmt, ...)					\
78	pr_notice("%s: " fmt, pd->name, ##__VA_ARGS__)
79#define pkt_info(pd, fmt, ...)						\
80	pr_info("%s: " fmt, pd->name, ##__VA_ARGS__)
81
82#define pkt_dbg(level, pd, fmt, ...)					\
83do {									\
84	if (level == 2 && PACKET_DEBUG >= 2)				\
85		pr_notice("%s: %s():" fmt,				\
86			  pd->name, __func__, ##__VA_ARGS__);		\
87	else if (level == 1 && PACKET_DEBUG >= 1)			\
88		pr_notice("%s: " fmt, pd->name, ##__VA_ARGS__);		\
89} while (0)
90
91#define MAX_SPEED 0xffff
92
93static DEFINE_MUTEX(pktcdvd_mutex);
94static struct pktcdvd_device *pkt_devs[MAX_WRITERS];
95static struct proc_dir_entry *pkt_proc;
96static int pktdev_major;
97static int write_congestion_on  = PKT_WRITE_CONGESTION_ON;
98static int write_congestion_off = PKT_WRITE_CONGESTION_OFF;
99static struct mutex ctl_mutex;	/* Serialize open/close/setup/teardown */
100static mempool_t *psd_pool;
101
102static struct class	*class_pktcdvd = NULL;    /* /sys/class/pktcdvd */
103static struct dentry	*pkt_debugfs_root = NULL; /* /sys/kernel/debug/pktcdvd */
104
105/* forward declaration */
106static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev);
107static int pkt_remove_dev(dev_t pkt_dev);
108static int pkt_seq_show(struct seq_file *m, void *p);
109
110static sector_t get_zone(sector_t sector, struct pktcdvd_device *pd)
111{
112	return (sector + pd->offset) & ~(sector_t)(pd->settings.size - 1);
113}
114
115/*
116 * create and register a pktcdvd kernel object.
117 */
118static struct pktcdvd_kobj* pkt_kobj_create(struct pktcdvd_device *pd,
119					const char* name,
120					struct kobject* parent,
121					struct kobj_type* ktype)
122{
123	struct pktcdvd_kobj *p;
124	int error;
125
126	p = kzalloc(sizeof(*p), GFP_KERNEL);
127	if (!p)
128		return NULL;
129	p->pd = pd;
130	error = kobject_init_and_add(&p->kobj, ktype, parent, "%s", name);
131	if (error) {
132		kobject_put(&p->kobj);
133		return NULL;
134	}
135	kobject_uevent(&p->kobj, KOBJ_ADD);
136	return p;
137}
138/*
139 * remove a pktcdvd kernel object.
140 */
141static void pkt_kobj_remove(struct pktcdvd_kobj *p)
142{
143	if (p)
144		kobject_put(&p->kobj);
145}
146/*
147 * default release function for pktcdvd kernel objects.
148 */
149static void pkt_kobj_release(struct kobject *kobj)
150{
151	kfree(to_pktcdvdkobj(kobj));
152}
153
154
155/**********************************************************
156 *
157 * sysfs interface for pktcdvd
158 * by (C) 2006  Thomas Maier <balagi@justmail.de>
159 *
160 **********************************************************/
161
162#define DEF_ATTR(_obj,_name,_mode) \
163	static struct attribute _obj = { .name = _name, .mode = _mode }
164
165/**********************************************************
166  /sys/class/pktcdvd/pktcdvd[0-7]/
167                     stat/reset
168                     stat/packets_started
169                     stat/packets_finished
170                     stat/kb_written
171                     stat/kb_read
172                     stat/kb_read_gather
173                     write_queue/size
174                     write_queue/congestion_off
175                     write_queue/congestion_on
176 **********************************************************/
177
178DEF_ATTR(kobj_pkt_attr_st1, "reset", 0200);
179DEF_ATTR(kobj_pkt_attr_st2, "packets_started", 0444);
180DEF_ATTR(kobj_pkt_attr_st3, "packets_finished", 0444);
181DEF_ATTR(kobj_pkt_attr_st4, "kb_written", 0444);
182DEF_ATTR(kobj_pkt_attr_st5, "kb_read", 0444);
183DEF_ATTR(kobj_pkt_attr_st6, "kb_read_gather", 0444);
184
185static struct attribute *kobj_pkt_attrs_stat[] = {
186	&kobj_pkt_attr_st1,
187	&kobj_pkt_attr_st2,
188	&kobj_pkt_attr_st3,
189	&kobj_pkt_attr_st4,
190	&kobj_pkt_attr_st5,
191	&kobj_pkt_attr_st6,
192	NULL
193};
194
195DEF_ATTR(kobj_pkt_attr_wq1, "size", 0444);
196DEF_ATTR(kobj_pkt_attr_wq2, "congestion_off", 0644);
197DEF_ATTR(kobj_pkt_attr_wq3, "congestion_on",  0644);
198
199static struct attribute *kobj_pkt_attrs_wqueue[] = {
200	&kobj_pkt_attr_wq1,
201	&kobj_pkt_attr_wq2,
202	&kobj_pkt_attr_wq3,
203	NULL
204};
205
206static ssize_t kobj_pkt_show(struct kobject *kobj,
207			struct attribute *attr, char *data)
208{
209	struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
210	int n = 0;
211	int v;
212	if (strcmp(attr->name, "packets_started") == 0) {
213		n = sprintf(data, "%lu\n", pd->stats.pkt_started);
214
215	} else if (strcmp(attr->name, "packets_finished") == 0) {
216		n = sprintf(data, "%lu\n", pd->stats.pkt_ended);
217
218	} else if (strcmp(attr->name, "kb_written") == 0) {
219		n = sprintf(data, "%lu\n", pd->stats.secs_w >> 1);
220
221	} else if (strcmp(attr->name, "kb_read") == 0) {
222		n = sprintf(data, "%lu\n", pd->stats.secs_r >> 1);
223
224	} else if (strcmp(attr->name, "kb_read_gather") == 0) {
225		n = sprintf(data, "%lu\n", pd->stats.secs_rg >> 1);
226
227	} else if (strcmp(attr->name, "size") == 0) {
228		spin_lock(&pd->lock);
229		v = pd->bio_queue_size;
230		spin_unlock(&pd->lock);
231		n = sprintf(data, "%d\n", v);
232
233	} else if (strcmp(attr->name, "congestion_off") == 0) {
234		spin_lock(&pd->lock);
235		v = pd->write_congestion_off;
236		spin_unlock(&pd->lock);
237		n = sprintf(data, "%d\n", v);
238
239	} else if (strcmp(attr->name, "congestion_on") == 0) {
240		spin_lock(&pd->lock);
241		v = pd->write_congestion_on;
242		spin_unlock(&pd->lock);
243		n = sprintf(data, "%d\n", v);
244	}
245	return n;
246}
247
248static void init_write_congestion_marks(int* lo, int* hi)
249{
250	if (*hi > 0) {
251		*hi = max(*hi, 500);
252		*hi = min(*hi, 1000000);
253		if (*lo <= 0)
254			*lo = *hi - 100;
255		else {
256			*lo = min(*lo, *hi - 100);
257			*lo = max(*lo, 100);
258		}
259	} else {
260		*hi = -1;
261		*lo = -1;
262	}
263}
264
265static ssize_t kobj_pkt_store(struct kobject *kobj,
266			struct attribute *attr,
267			const char *data, size_t len)
268{
269	struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
270	int val;
271
272	if (strcmp(attr->name, "reset") == 0 && len > 0) {
273		pd->stats.pkt_started = 0;
274		pd->stats.pkt_ended = 0;
275		pd->stats.secs_w = 0;
276		pd->stats.secs_rg = 0;
277		pd->stats.secs_r = 0;
278
279	} else if (strcmp(attr->name, "congestion_off") == 0
280		   && sscanf(data, "%d", &val) == 1) {
281		spin_lock(&pd->lock);
282		pd->write_congestion_off = val;
283		init_write_congestion_marks(&pd->write_congestion_off,
284					&pd->write_congestion_on);
285		spin_unlock(&pd->lock);
286
287	} else if (strcmp(attr->name, "congestion_on") == 0
288		   && sscanf(data, "%d", &val) == 1) {
289		spin_lock(&pd->lock);
290		pd->write_congestion_on = val;
291		init_write_congestion_marks(&pd->write_congestion_off,
292					&pd->write_congestion_on);
293		spin_unlock(&pd->lock);
294	}
295	return len;
296}
297
298static const struct sysfs_ops kobj_pkt_ops = {
299	.show = kobj_pkt_show,
300	.store = kobj_pkt_store
301};
302static struct kobj_type kobj_pkt_type_stat = {
303	.release = pkt_kobj_release,
304	.sysfs_ops = &kobj_pkt_ops,
305	.default_attrs = kobj_pkt_attrs_stat
306};
307static struct kobj_type kobj_pkt_type_wqueue = {
308	.release = pkt_kobj_release,
309	.sysfs_ops = &kobj_pkt_ops,
310	.default_attrs = kobj_pkt_attrs_wqueue
311};
312
313static void pkt_sysfs_dev_new(struct pktcdvd_device *pd)
314{
315	if (class_pktcdvd) {
316		pd->dev = device_create(class_pktcdvd, NULL, MKDEV(0, 0), NULL,
317					"%s", pd->name);
318		if (IS_ERR(pd->dev))
319			pd->dev = NULL;
320	}
321	if (pd->dev) {
322		pd->kobj_stat = pkt_kobj_create(pd, "stat",
323					&pd->dev->kobj,
324					&kobj_pkt_type_stat);
325		pd->kobj_wqueue = pkt_kobj_create(pd, "write_queue",
326					&pd->dev->kobj,
327					&kobj_pkt_type_wqueue);
328	}
329}
330
331static void pkt_sysfs_dev_remove(struct pktcdvd_device *pd)
332{
333	pkt_kobj_remove(pd->kobj_stat);
334	pkt_kobj_remove(pd->kobj_wqueue);
335	if (class_pktcdvd)
336		device_unregister(pd->dev);
337}
338
339
340/********************************************************************
341  /sys/class/pktcdvd/
342                     add            map block device
343                     remove         unmap packet dev
344                     device_map     show mappings
345 *******************************************************************/
346
347static void class_pktcdvd_release(struct class *cls)
348{
349	kfree(cls);
350}
351static ssize_t class_pktcdvd_show_map(struct class *c,
352					struct class_attribute *attr,
353					char *data)
354{
355	int n = 0;
356	int idx;
357	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
358	for (idx = 0; idx < MAX_WRITERS; idx++) {
359		struct pktcdvd_device *pd = pkt_devs[idx];
360		if (!pd)
361			continue;
362		n += sprintf(data+n, "%s %u:%u %u:%u\n",
363			pd->name,
364			MAJOR(pd->pkt_dev), MINOR(pd->pkt_dev),
365			MAJOR(pd->bdev->bd_dev),
366			MINOR(pd->bdev->bd_dev));
367	}
368	mutex_unlock(&ctl_mutex);
369	return n;
370}
371
372static ssize_t class_pktcdvd_store_add(struct class *c,
373					struct class_attribute *attr,
374					const char *buf,
375					size_t count)
376{
377	unsigned int major, minor;
378
379	if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
380		/* pkt_setup_dev() expects caller to hold reference to self */
381		if (!try_module_get(THIS_MODULE))
382			return -ENODEV;
383
384		pkt_setup_dev(MKDEV(major, minor), NULL);
385
386		module_put(THIS_MODULE);
387
388		return count;
389	}
390
391	return -EINVAL;
392}
393
394static ssize_t class_pktcdvd_store_remove(struct class *c,
395					  struct class_attribute *attr,
396					  const char *buf,
397					size_t count)
398{
399	unsigned int major, minor;
400	if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
401		pkt_remove_dev(MKDEV(major, minor));
402		return count;
403	}
404	return -EINVAL;
405}
406
407static struct class_attribute class_pktcdvd_attrs[] = {
408 __ATTR(add,            0200, NULL, class_pktcdvd_store_add),
409 __ATTR(remove,         0200, NULL, class_pktcdvd_store_remove),
410 __ATTR(device_map,     0444, class_pktcdvd_show_map, NULL),
411 __ATTR_NULL
412};
413
414
415static int pkt_sysfs_init(void)
416{
417	int ret = 0;
418
419	/*
420	 * create control files in sysfs
421	 * /sys/class/pktcdvd/...
422	 */
423	class_pktcdvd = kzalloc(sizeof(*class_pktcdvd), GFP_KERNEL);
424	if (!class_pktcdvd)
425		return -ENOMEM;
426	class_pktcdvd->name = DRIVER_NAME;
427	class_pktcdvd->owner = THIS_MODULE;
428	class_pktcdvd->class_release = class_pktcdvd_release;
429	class_pktcdvd->class_attrs = class_pktcdvd_attrs;
430	ret = class_register(class_pktcdvd);
431	if (ret) {
432		kfree(class_pktcdvd);
433		class_pktcdvd = NULL;
434		pr_err("failed to create class pktcdvd\n");
435		return ret;
436	}
437	return 0;
438}
439
440static void pkt_sysfs_cleanup(void)
441{
442	if (class_pktcdvd)
443		class_destroy(class_pktcdvd);
444	class_pktcdvd = NULL;
445}
446
447/********************************************************************
448  entries in debugfs
449
450  /sys/kernel/debug/pktcdvd[0-7]/
451			info
452
453 *******************************************************************/
454
455static int pkt_debugfs_seq_show(struct seq_file *m, void *p)
456{
457	return pkt_seq_show(m, p);
458}
459
460static int pkt_debugfs_fops_open(struct inode *inode, struct file *file)
461{
462	return single_open(file, pkt_debugfs_seq_show, inode->i_private);
463}
464
465static const struct file_operations debug_fops = {
466	.open		= pkt_debugfs_fops_open,
467	.read		= seq_read,
468	.llseek		= seq_lseek,
469	.release	= single_release,
470	.owner		= THIS_MODULE,
471};
472
473static void pkt_debugfs_dev_new(struct pktcdvd_device *pd)
474{
475	if (!pkt_debugfs_root)
476		return;
477	pd->dfs_d_root = debugfs_create_dir(pd->name, pkt_debugfs_root);
478	if (!pd->dfs_d_root)
479		return;
480
481	pd->dfs_f_info = debugfs_create_file("info", S_IRUGO,
482				pd->dfs_d_root, pd, &debug_fops);
483}
484
485static void pkt_debugfs_dev_remove(struct pktcdvd_device *pd)
486{
487	if (!pkt_debugfs_root)
488		return;
489	debugfs_remove(pd->dfs_f_info);
490	debugfs_remove(pd->dfs_d_root);
491	pd->dfs_f_info = NULL;
492	pd->dfs_d_root = NULL;
493}
494
495static void pkt_debugfs_init(void)
496{
497	pkt_debugfs_root = debugfs_create_dir(DRIVER_NAME, NULL);
498}
499
500static void pkt_debugfs_cleanup(void)
501{
502	debugfs_remove(pkt_debugfs_root);
503	pkt_debugfs_root = NULL;
504}
505
506/* ----------------------------------------------------------*/
507
508
509static void pkt_bio_finished(struct pktcdvd_device *pd)
510{
511	BUG_ON(atomic_read(&pd->cdrw.pending_bios) <= 0);
512	if (atomic_dec_and_test(&pd->cdrw.pending_bios)) {
513		pkt_dbg(2, pd, "queue empty\n");
514		atomic_set(&pd->iosched.attention, 1);
515		wake_up(&pd->wqueue);
516	}
517}
518
519/*
520 * Allocate a packet_data struct
521 */
522static struct packet_data *pkt_alloc_packet_data(int frames)
523{
524	int i;
525	struct packet_data *pkt;
526
527	pkt = kzalloc(sizeof(struct packet_data), GFP_KERNEL);
528	if (!pkt)
529		goto no_pkt;
530
531	pkt->frames = frames;
532	pkt->w_bio = bio_kmalloc(GFP_KERNEL, frames);
533	if (!pkt->w_bio)
534		goto no_bio;
535
536	for (i = 0; i < frames / FRAMES_PER_PAGE; i++) {
537		pkt->pages[i] = alloc_page(GFP_KERNEL|__GFP_ZERO);
538		if (!pkt->pages[i])
539			goto no_page;
540	}
541
542	spin_lock_init(&pkt->lock);
543	bio_list_init(&pkt->orig_bios);
544
545	for (i = 0; i < frames; i++) {
546		struct bio *bio = bio_kmalloc(GFP_KERNEL, 1);
547		if (!bio)
548			goto no_rd_bio;
549
550		pkt->r_bios[i] = bio;
551	}
552
553	return pkt;
554
555no_rd_bio:
556	for (i = 0; i < frames; i++) {
557		struct bio *bio = pkt->r_bios[i];
558		if (bio)
559			bio_put(bio);
560	}
561
562no_page:
563	for (i = 0; i < frames / FRAMES_PER_PAGE; i++)
564		if (pkt->pages[i])
565			__free_page(pkt->pages[i]);
566	bio_put(pkt->w_bio);
567no_bio:
568	kfree(pkt);
569no_pkt:
570	return NULL;
571}
572
573/*
574 * Free a packet_data struct
575 */
576static void pkt_free_packet_data(struct packet_data *pkt)
577{
578	int i;
579
580	for (i = 0; i < pkt->frames; i++) {
581		struct bio *bio = pkt->r_bios[i];
582		if (bio)
583			bio_put(bio);
584	}
585	for (i = 0; i < pkt->frames / FRAMES_PER_PAGE; i++)
586		__free_page(pkt->pages[i]);
587	bio_put(pkt->w_bio);
588	kfree(pkt);
589}
590
591static void pkt_shrink_pktlist(struct pktcdvd_device *pd)
592{
593	struct packet_data *pkt, *next;
594
595	BUG_ON(!list_empty(&pd->cdrw.pkt_active_list));
596
597	list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_free_list, list) {
598		pkt_free_packet_data(pkt);
599	}
600	INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
601}
602
603static int pkt_grow_pktlist(struct pktcdvd_device *pd, int nr_packets)
604{
605	struct packet_data *pkt;
606
607	BUG_ON(!list_empty(&pd->cdrw.pkt_free_list));
608
609	while (nr_packets > 0) {
610		pkt = pkt_alloc_packet_data(pd->settings.size >> 2);
611		if (!pkt) {
612			pkt_shrink_pktlist(pd);
613			return 0;
614		}
615		pkt->id = nr_packets;
616		pkt->pd = pd;
617		list_add(&pkt->list, &pd->cdrw.pkt_free_list);
618		nr_packets--;
619	}
620	return 1;
621}
622
623static inline struct pkt_rb_node *pkt_rbtree_next(struct pkt_rb_node *node)
624{
625	struct rb_node *n = rb_next(&node->rb_node);
626	if (!n)
627		return NULL;
628	return rb_entry(n, struct pkt_rb_node, rb_node);
629}
630
631static void pkt_rbtree_erase(struct pktcdvd_device *pd, struct pkt_rb_node *node)
632{
633	rb_erase(&node->rb_node, &pd->bio_queue);
634	mempool_free(node, pd->rb_pool);
635	pd->bio_queue_size--;
636	BUG_ON(pd->bio_queue_size < 0);
637}
638
639/*
640 * Find the first node in the pd->bio_queue rb tree with a starting sector >= s.
641 */
642static struct pkt_rb_node *pkt_rbtree_find(struct pktcdvd_device *pd, sector_t s)
643{
644	struct rb_node *n = pd->bio_queue.rb_node;
645	struct rb_node *next;
646	struct pkt_rb_node *tmp;
647
648	if (!n) {
649		BUG_ON(pd->bio_queue_size > 0);
650		return NULL;
651	}
652
653	for (;;) {
654		tmp = rb_entry(n, struct pkt_rb_node, rb_node);
655		if (s <= tmp->bio->bi_iter.bi_sector)
656			next = n->rb_left;
657		else
658			next = n->rb_right;
659		if (!next)
660			break;
661		n = next;
662	}
663
664	if (s > tmp->bio->bi_iter.bi_sector) {
665		tmp = pkt_rbtree_next(tmp);
666		if (!tmp)
667			return NULL;
668	}
669	BUG_ON(s > tmp->bio->bi_iter.bi_sector);
670	return tmp;
671}
672
673/*
674 * Insert a node into the pd->bio_queue rb tree.
675 */
676static void pkt_rbtree_insert(struct pktcdvd_device *pd, struct pkt_rb_node *node)
677{
678	struct rb_node **p = &pd->bio_queue.rb_node;
679	struct rb_node *parent = NULL;
680	sector_t s = node->bio->bi_iter.bi_sector;
681	struct pkt_rb_node *tmp;
682
683	while (*p) {
684		parent = *p;
685		tmp = rb_entry(parent, struct pkt_rb_node, rb_node);
686		if (s < tmp->bio->bi_iter.bi_sector)
687			p = &(*p)->rb_left;
688		else
689			p = &(*p)->rb_right;
690	}
691	rb_link_node(&node->rb_node, parent, p);
692	rb_insert_color(&node->rb_node, &pd->bio_queue);
693	pd->bio_queue_size++;
694}
695
696/*
697 * Send a packet_command to the underlying block device and
698 * wait for completion.
699 */
700static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *cgc)
701{
702	struct request_queue *q = bdev_get_queue(pd->bdev);
703	struct request *rq;
704	int ret = 0;
705
706	rq = blk_get_request(q, (cgc->data_direction == CGC_DATA_WRITE) ?
707			     WRITE : READ, __GFP_RECLAIM);
708	if (IS_ERR(rq))
709		return PTR_ERR(rq);
710	blk_rq_set_block_pc(rq);
711
712	if (cgc->buflen) {
713		ret = blk_rq_map_kern(q, rq, cgc->buffer, cgc->buflen,
714				      __GFP_RECLAIM);
715		if (ret)
716			goto out;
717	}
718
719	rq->cmd_len = COMMAND_SIZE(cgc->cmd[0]);
720	memcpy(rq->cmd, cgc->cmd, CDROM_PACKET_SIZE);
721
722	rq->timeout = 60*HZ;
723	if (cgc->quiet)
724		rq->cmd_flags |= REQ_QUIET;
725
726	blk_execute_rq(rq->q, pd->bdev->bd_disk, rq, 0);
727	if (rq->errors)
728		ret = -EIO;
729out:
730	blk_put_request(rq);
731	return ret;
732}
733
734static const char *sense_key_string(__u8 index)
735{
736	static const char * const info[] = {
737		"No sense", "Recovered error", "Not ready",
738		"Medium error", "Hardware error", "Illegal request",
739		"Unit attention", "Data protect", "Blank check",
740	};
741
742	return index < ARRAY_SIZE(info) ? info[index] : "INVALID";
743}
744
745/*
746 * A generic sense dump / resolve mechanism should be implemented across
747 * all ATAPI + SCSI devices.
748 */
749static void pkt_dump_sense(struct pktcdvd_device *pd,
750			   struct packet_command *cgc)
751{
752	struct request_sense *sense = cgc->sense;
753
754	if (sense)
755		pkt_err(pd, "%*ph - sense %02x.%02x.%02x (%s)\n",
756			CDROM_PACKET_SIZE, cgc->cmd,
757			sense->sense_key, sense->asc, sense->ascq,
758			sense_key_string(sense->sense_key));
759	else
760		pkt_err(pd, "%*ph - no sense\n", CDROM_PACKET_SIZE, cgc->cmd);
761}
762
763/*
764 * flush the drive cache to media
765 */
766static int pkt_flush_cache(struct pktcdvd_device *pd)
767{
768	struct packet_command cgc;
769
770	init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
771	cgc.cmd[0] = GPCMD_FLUSH_CACHE;
772	cgc.quiet = 1;
773
774	/*
775	 * the IMMED bit -- we default to not setting it, although that
776	 * would allow a much faster close, this is safer
777	 */
778#if 0
779	cgc.cmd[1] = 1 << 1;
780#endif
781	return pkt_generic_packet(pd, &cgc);
782}
783
784/*
785 * speed is given as the normal factor, e.g. 4 for 4x
786 */
787static noinline_for_stack int pkt_set_speed(struct pktcdvd_device *pd,
788				unsigned write_speed, unsigned read_speed)
789{
790	struct packet_command cgc;
791	struct request_sense sense;
792	int ret;
793
794	init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
795	cgc.sense = &sense;
796	cgc.cmd[0] = GPCMD_SET_SPEED;
797	cgc.cmd[2] = (read_speed >> 8) & 0xff;
798	cgc.cmd[3] = read_speed & 0xff;
799	cgc.cmd[4] = (write_speed >> 8) & 0xff;
800	cgc.cmd[5] = write_speed & 0xff;
801
802	if ((ret = pkt_generic_packet(pd, &cgc)))
803		pkt_dump_sense(pd, &cgc);
804
805	return ret;
806}
807
808/*
809 * Queue a bio for processing by the low-level CD device. Must be called
810 * from process context.
811 */
812static void pkt_queue_bio(struct pktcdvd_device *pd, struct bio *bio)
813{
814	spin_lock(&pd->iosched.lock);
815	if (bio_data_dir(bio) == READ)
816		bio_list_add(&pd->iosched.read_queue, bio);
817	else
818		bio_list_add(&pd->iosched.write_queue, bio);
819	spin_unlock(&pd->iosched.lock);
820
821	atomic_set(&pd->iosched.attention, 1);
822	wake_up(&pd->wqueue);
823}
824
825/*
826 * Process the queued read/write requests. This function handles special
827 * requirements for CDRW drives:
828 * - A cache flush command must be inserted before a read request if the
829 *   previous request was a write.
830 * - Switching between reading and writing is slow, so don't do it more often
831 *   than necessary.
832 * - Optimize for throughput at the expense of latency. This means that streaming
833 *   writes will never be interrupted by a read, but if the drive has to seek
834 *   before the next write, switch to reading instead if there are any pending
835 *   read requests.
836 * - Set the read speed according to current usage pattern. When only reading
837 *   from the device, it's best to use the highest possible read speed, but
838 *   when switching often between reading and writing, it's better to have the
839 *   same read and write speeds.
840 */
841static void pkt_iosched_process_queue(struct pktcdvd_device *pd)
842{
843
844	if (atomic_read(&pd->iosched.attention) == 0)
845		return;
846	atomic_set(&pd->iosched.attention, 0);
847
848	for (;;) {
849		struct bio *bio;
850		int reads_queued, writes_queued;
851
852		spin_lock(&pd->iosched.lock);
853		reads_queued = !bio_list_empty(&pd->iosched.read_queue);
854		writes_queued = !bio_list_empty(&pd->iosched.write_queue);
855		spin_unlock(&pd->iosched.lock);
856
857		if (!reads_queued && !writes_queued)
858			break;
859
860		if (pd->iosched.writing) {
861			int need_write_seek = 1;
862			spin_lock(&pd->iosched.lock);
863			bio = bio_list_peek(&pd->iosched.write_queue);
864			spin_unlock(&pd->iosched.lock);
865			if (bio && (bio->bi_iter.bi_sector ==
866				    pd->iosched.last_write))
867				need_write_seek = 0;
868			if (need_write_seek && reads_queued) {
869				if (atomic_read(&pd->cdrw.pending_bios) > 0) {
870					pkt_dbg(2, pd, "write, waiting\n");
871					break;
872				}
873				pkt_flush_cache(pd);
874				pd->iosched.writing = 0;
875			}
876		} else {
877			if (!reads_queued && writes_queued) {
878				if (atomic_read(&pd->cdrw.pending_bios) > 0) {
879					pkt_dbg(2, pd, "read, waiting\n");
880					break;
881				}
882				pd->iosched.writing = 1;
883			}
884		}
885
886		spin_lock(&pd->iosched.lock);
887		if (pd->iosched.writing)
888			bio = bio_list_pop(&pd->iosched.write_queue);
889		else
890			bio = bio_list_pop(&pd->iosched.read_queue);
891		spin_unlock(&pd->iosched.lock);
892
893		if (!bio)
894			continue;
895
896		if (bio_data_dir(bio) == READ)
897			pd->iosched.successive_reads +=
898				bio->bi_iter.bi_size >> 10;
899		else {
900			pd->iosched.successive_reads = 0;
901			pd->iosched.last_write = bio_end_sector(bio);
902		}
903		if (pd->iosched.successive_reads >= HI_SPEED_SWITCH) {
904			if (pd->read_speed == pd->write_speed) {
905				pd->read_speed = MAX_SPEED;
906				pkt_set_speed(pd, pd->write_speed, pd->read_speed);
907			}
908		} else {
909			if (pd->read_speed != pd->write_speed) {
910				pd->read_speed = pd->write_speed;
911				pkt_set_speed(pd, pd->write_speed, pd->read_speed);
912			}
913		}
914
915		atomic_inc(&pd->cdrw.pending_bios);
916		generic_make_request(bio);
917	}
918}
919
920/*
921 * Special care is needed if the underlying block device has a small
922 * max_phys_segments value.
923 */
924static int pkt_set_segment_merging(struct pktcdvd_device *pd, struct request_queue *q)
925{
926	if ((pd->settings.size << 9) / CD_FRAMESIZE
927	    <= queue_max_segments(q)) {
928		/*
929		 * The cdrom device can handle one segment/frame
930		 */
931		clear_bit(PACKET_MERGE_SEGS, &pd->flags);
932		return 0;
933	} else if ((pd->settings.size << 9) / PAGE_SIZE
934		   <= queue_max_segments(q)) {
935		/*
936		 * We can handle this case at the expense of some extra memory
937		 * copies during write operations
938		 */
939		set_bit(PACKET_MERGE_SEGS, &pd->flags);
940		return 0;
941	} else {
942		pkt_err(pd, "cdrom max_phys_segments too small\n");
943		return -EIO;
944	}
945}
946
947/*
948 * Copy all data for this packet to pkt->pages[], so that
949 * a) The number of required segments for the write bio is minimized, which
950 *    is necessary for some scsi controllers.
951 * b) The data can be used as cache to avoid read requests if we receive a
952 *    new write request for the same zone.
953 */
954static void pkt_make_local_copy(struct packet_data *pkt, struct bio_vec *bvec)
955{
956	int f, p, offs;
957
958	/* Copy all data to pkt->pages[] */
959	p = 0;
960	offs = 0;
961	for (f = 0; f < pkt->frames; f++) {
962		if (bvec[f].bv_page != pkt->pages[p]) {
963			void *vfrom = kmap_atomic(bvec[f].bv_page) + bvec[f].bv_offset;
964			void *vto = page_address(pkt->pages[p]) + offs;
965			memcpy(vto, vfrom, CD_FRAMESIZE);
966			kunmap_atomic(vfrom);
967			bvec[f].bv_page = pkt->pages[p];
968			bvec[f].bv_offset = offs;
969		} else {
970			BUG_ON(bvec[f].bv_offset != offs);
971		}
972		offs += CD_FRAMESIZE;
973		if (offs >= PAGE_SIZE) {
974			offs = 0;
975			p++;
976		}
977	}
978}
979
980static void pkt_end_io_read(struct bio *bio)
981{
982	struct packet_data *pkt = bio->bi_private;
983	struct pktcdvd_device *pd = pkt->pd;
984	BUG_ON(!pd);
985
986	pkt_dbg(2, pd, "bio=%p sec0=%llx sec=%llx err=%d\n",
987		bio, (unsigned long long)pkt->sector,
988		(unsigned long long)bio->bi_iter.bi_sector, bio->bi_error);
989
990	if (bio->bi_error)
991		atomic_inc(&pkt->io_errors);
992	if (atomic_dec_and_test(&pkt->io_wait)) {
993		atomic_inc(&pkt->run_sm);
994		wake_up(&pd->wqueue);
995	}
996	pkt_bio_finished(pd);
997}
998
999static void pkt_end_io_packet_write(struct bio *bio)
1000{
1001	struct packet_data *pkt = bio->bi_private;
1002	struct pktcdvd_device *pd = pkt->pd;
1003	BUG_ON(!pd);
1004
1005	pkt_dbg(2, pd, "id=%d, err=%d\n", pkt->id, bio->bi_error);
1006
1007	pd->stats.pkt_ended++;
1008
1009	pkt_bio_finished(pd);
1010	atomic_dec(&pkt->io_wait);
1011	atomic_inc(&pkt->run_sm);
1012	wake_up(&pd->wqueue);
1013}
1014
1015/*
1016 * Schedule reads for the holes in a packet
1017 */
1018static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1019{
1020	int frames_read = 0;
1021	struct bio *bio;
1022	int f;
1023	char written[PACKET_MAX_SIZE];
1024
1025	BUG_ON(bio_list_empty(&pkt->orig_bios));
1026
1027	atomic_set(&pkt->io_wait, 0);
1028	atomic_set(&pkt->io_errors, 0);
1029
1030	/*
1031	 * Figure out which frames we need to read before we can write.
1032	 */
1033	memset(written, 0, sizeof(written));
1034	spin_lock(&pkt->lock);
1035	bio_list_for_each(bio, &pkt->orig_bios) {
1036		int first_frame = (bio->bi_iter.bi_sector - pkt->sector) /
1037			(CD_FRAMESIZE >> 9);
1038		int num_frames = bio->bi_iter.bi_size / CD_FRAMESIZE;
1039		pd->stats.secs_w += num_frames * (CD_FRAMESIZE >> 9);
1040		BUG_ON(first_frame < 0);
1041		BUG_ON(first_frame + num_frames > pkt->frames);
1042		for (f = first_frame; f < first_frame + num_frames; f++)
1043			written[f] = 1;
1044	}
1045	spin_unlock(&pkt->lock);
1046
1047	if (pkt->cache_valid) {
1048		pkt_dbg(2, pd, "zone %llx cached\n",
1049			(unsigned long long)pkt->sector);
1050		goto out_account;
1051	}
1052
1053	/*
1054	 * Schedule reads for missing parts of the packet.
1055	 */
1056	for (f = 0; f < pkt->frames; f++) {
1057		int p, offset;
1058
1059		if (written[f])
1060			continue;
1061
1062		bio = pkt->r_bios[f];
1063		bio_reset(bio);
1064		bio->bi_iter.bi_sector = pkt->sector + f * (CD_FRAMESIZE >> 9);
1065		bio->bi_bdev = pd->bdev;
1066		bio->bi_end_io = pkt_end_io_read;
1067		bio->bi_private = pkt;
1068
1069		p = (f * CD_FRAMESIZE) / PAGE_SIZE;
1070		offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1071		pkt_dbg(2, pd, "Adding frame %d, page:%p offs:%d\n",
1072			f, pkt->pages[p], offset);
1073		if (!bio_add_page(bio, pkt->pages[p], CD_FRAMESIZE, offset))
1074			BUG();
1075
1076		atomic_inc(&pkt->io_wait);
1077		bio->bi_rw = READ;
1078		pkt_queue_bio(pd, bio);
1079		frames_read++;
1080	}
1081
1082out_account:
1083	pkt_dbg(2, pd, "need %d frames for zone %llx\n",
1084		frames_read, (unsigned long long)pkt->sector);
1085	pd->stats.pkt_started++;
1086	pd->stats.secs_rg += frames_read * (CD_FRAMESIZE >> 9);
1087}
1088
1089/*
1090 * Find a packet matching zone, or the least recently used packet if
1091 * there is no match.
1092 */
1093static struct packet_data *pkt_get_packet_data(struct pktcdvd_device *pd, int zone)
1094{
1095	struct packet_data *pkt;
1096
1097	list_for_each_entry(pkt, &pd->cdrw.pkt_free_list, list) {
1098		if (pkt->sector == zone || pkt->list.next == &pd->cdrw.pkt_free_list) {
1099			list_del_init(&pkt->list);
1100			if (pkt->sector != zone)
1101				pkt->cache_valid = 0;
1102			return pkt;
1103		}
1104	}
1105	BUG();
1106	return NULL;
1107}
1108
1109static void pkt_put_packet_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1110{
1111	if (pkt->cache_valid) {
1112		list_add(&pkt->list, &pd->cdrw.pkt_free_list);
1113	} else {
1114		list_add_tail(&pkt->list, &pd->cdrw.pkt_free_list);
1115	}
1116}
1117
1118/*
1119 * recover a failed write, query for relocation if possible
1120 *
1121 * returns 1 if recovery is possible, or 0 if not
1122 *
1123 */
1124static int pkt_start_recovery(struct packet_data *pkt)
1125{
1126	/*
1127	 * FIXME. We need help from the file system to implement
1128	 * recovery handling.
1129	 */
1130	return 0;
1131#if 0
1132	struct request *rq = pkt->rq;
1133	struct pktcdvd_device *pd = rq->rq_disk->private_data;
1134	struct block_device *pkt_bdev;
1135	struct super_block *sb = NULL;
1136	unsigned long old_block, new_block;
1137	sector_t new_sector;
1138
1139	pkt_bdev = bdget(kdev_t_to_nr(pd->pkt_dev));
1140	if (pkt_bdev) {
1141		sb = get_super(pkt_bdev);
1142		bdput(pkt_bdev);
1143	}
1144
1145	if (!sb)
1146		return 0;
1147
1148	if (!sb->s_op->relocate_blocks)
1149		goto out;
1150
1151	old_block = pkt->sector / (CD_FRAMESIZE >> 9);
1152	if (sb->s_op->relocate_blocks(sb, old_block, &new_block))
1153		goto out;
1154
1155	new_sector = new_block * (CD_FRAMESIZE >> 9);
1156	pkt->sector = new_sector;
1157
1158	bio_reset(pkt->bio);
1159	pkt->bio->bi_bdev = pd->bdev;
1160	pkt->bio->bi_rw = REQ_WRITE;
1161	pkt->bio->bi_iter.bi_sector = new_sector;
1162	pkt->bio->bi_iter.bi_size = pkt->frames * CD_FRAMESIZE;
1163	pkt->bio->bi_vcnt = pkt->frames;
1164
1165	pkt->bio->bi_end_io = pkt_end_io_packet_write;
1166	pkt->bio->bi_private = pkt;
1167
1168	drop_super(sb);
1169	return 1;
1170
1171out:
1172	drop_super(sb);
1173	return 0;
1174#endif
1175}
1176
1177static inline void pkt_set_state(struct packet_data *pkt, enum packet_data_state state)
1178{
1179#if PACKET_DEBUG > 1
1180	static const char *state_name[] = {
1181		"IDLE", "WAITING", "READ_WAIT", "WRITE_WAIT", "RECOVERY", "FINISHED"
1182	};
1183	enum packet_data_state old_state = pkt->state;
1184	pkt_dbg(2, pd, "pkt %2d : s=%6llx %s -> %s\n",
1185		pkt->id, (unsigned long long)pkt->sector,
1186		state_name[old_state], state_name[state]);
1187#endif
1188	pkt->state = state;
1189}
1190
1191/*
1192 * Scan the work queue to see if we can start a new packet.
1193 * returns non-zero if any work was done.
1194 */
1195static int pkt_handle_queue(struct pktcdvd_device *pd)
1196{
1197	struct packet_data *pkt, *p;
1198	struct bio *bio = NULL;
1199	sector_t zone = 0; /* Suppress gcc warning */
1200	struct pkt_rb_node *node, *first_node;
1201	struct rb_node *n;
1202	int wakeup;
1203
1204	atomic_set(&pd->scan_queue, 0);
1205
1206	if (list_empty(&pd->cdrw.pkt_free_list)) {
1207		pkt_dbg(2, pd, "no pkt\n");
1208		return 0;
1209	}
1210
1211	/*
1212	 * Try to find a zone we are not already working on.
1213	 */
1214	spin_lock(&pd->lock);
1215	first_node = pkt_rbtree_find(pd, pd->current_sector);
1216	if (!first_node) {
1217		n = rb_first(&pd->bio_queue);
1218		if (n)
1219			first_node = rb_entry(n, struct pkt_rb_node, rb_node);
1220	}
1221	node = first_node;
1222	while (node) {
1223		bio = node->bio;
1224		zone = get_zone(bio->bi_iter.bi_sector, pd);
1225		list_for_each_entry(p, &pd->cdrw.pkt_active_list, list) {
1226			if (p->sector == zone) {
1227				bio = NULL;
1228				goto try_next_bio;
1229			}
1230		}
1231		break;
1232try_next_bio:
1233		node = pkt_rbtree_next(node);
1234		if (!node) {
1235			n = rb_first(&pd->bio_queue);
1236			if (n)
1237				node = rb_entry(n, struct pkt_rb_node, rb_node);
1238		}
1239		if (node == first_node)
1240			node = NULL;
1241	}
1242	spin_unlock(&pd->lock);
1243	if (!bio) {
1244		pkt_dbg(2, pd, "no bio\n");
1245		return 0;
1246	}
1247
1248	pkt = pkt_get_packet_data(pd, zone);
1249
1250	pd->current_sector = zone + pd->settings.size;
1251	pkt->sector = zone;
1252	BUG_ON(pkt->frames != pd->settings.size >> 2);
1253	pkt->write_size = 0;
1254
1255	/*
1256	 * Scan work queue for bios in the same zone and link them
1257	 * to this packet.
1258	 */
1259	spin_lock(&pd->lock);
1260	pkt_dbg(2, pd, "looking for zone %llx\n", (unsigned long long)zone);
1261	while ((node = pkt_rbtree_find(pd, zone)) != NULL) {
1262		bio = node->bio;
1263		pkt_dbg(2, pd, "found zone=%llx\n", (unsigned long long)
1264			get_zone(bio->bi_iter.bi_sector, pd));
1265		if (get_zone(bio->bi_iter.bi_sector, pd) != zone)
1266			break;
1267		pkt_rbtree_erase(pd, node);
1268		spin_lock(&pkt->lock);
1269		bio_list_add(&pkt->orig_bios, bio);
1270		pkt->write_size += bio->bi_iter.bi_size / CD_FRAMESIZE;
1271		spin_unlock(&pkt->lock);
1272	}
1273	/* check write congestion marks, and if bio_queue_size is
1274	   below, wake up any waiters */
1275	wakeup = (pd->write_congestion_on > 0
1276	 		&& pd->bio_queue_size <= pd->write_congestion_off);
1277	spin_unlock(&pd->lock);
1278	if (wakeup) {
1279		clear_bdi_congested(&pd->disk->queue->backing_dev_info,
1280					BLK_RW_ASYNC);
1281	}
1282
1283	pkt->sleep_time = max(PACKET_WAIT_TIME, 1);
1284	pkt_set_state(pkt, PACKET_WAITING_STATE);
1285	atomic_set(&pkt->run_sm, 1);
1286
1287	spin_lock(&pd->cdrw.active_list_lock);
1288	list_add(&pkt->list, &pd->cdrw.pkt_active_list);
1289	spin_unlock(&pd->cdrw.active_list_lock);
1290
1291	return 1;
1292}
1293
1294/*
1295 * Assemble a bio to write one packet and queue the bio for processing
1296 * by the underlying block device.
1297 */
1298static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
1299{
1300	int f;
1301	struct bio_vec *bvec = pkt->w_bio->bi_io_vec;
1302
1303	bio_reset(pkt->w_bio);
1304	pkt->w_bio->bi_iter.bi_sector = pkt->sector;
1305	pkt->w_bio->bi_bdev = pd->bdev;
1306	pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
1307	pkt->w_bio->bi_private = pkt;
1308
1309	/* XXX: locking? */
1310	for (f = 0; f < pkt->frames; f++) {
1311		bvec[f].bv_page = pkt->pages[(f * CD_FRAMESIZE) / PAGE_SIZE];
1312		bvec[f].bv_offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1313		if (!bio_add_page(pkt->w_bio, bvec[f].bv_page, CD_FRAMESIZE, bvec[f].bv_offset))
1314			BUG();
1315	}
1316	pkt_dbg(2, pd, "vcnt=%d\n", pkt->w_bio->bi_vcnt);
1317
1318	/*
1319	 * Fill-in bvec with data from orig_bios.
1320	 */
1321	spin_lock(&pkt->lock);
1322	bio_copy_data(pkt->w_bio, pkt->orig_bios.head);
1323
1324	pkt_set_state(pkt, PACKET_WRITE_WAIT_STATE);
1325	spin_unlock(&pkt->lock);
1326
1327	pkt_dbg(2, pd, "Writing %d frames for zone %llx\n",
1328		pkt->write_size, (unsigned long long)pkt->sector);
1329
1330	if (test_bit(PACKET_MERGE_SEGS, &pd->flags) || (pkt->write_size < pkt->frames)) {
1331		pkt_make_local_copy(pkt, bvec);
1332		pkt->cache_valid = 1;
1333	} else {
1334		pkt->cache_valid = 0;
1335	}
1336
1337	/* Start the write request */
1338	atomic_set(&pkt->io_wait, 1);
1339	pkt->w_bio->bi_rw = WRITE;
1340	pkt_queue_bio(pd, pkt->w_bio);
1341}
1342
1343static void pkt_finish_packet(struct packet_data *pkt, int error)
1344{
1345	struct bio *bio;
1346
1347	if (error)
1348		pkt->cache_valid = 0;
1349
1350	/* Finish all bios corresponding to this packet */
1351	while ((bio = bio_list_pop(&pkt->orig_bios))) {
1352		bio->bi_error = error;
1353		bio_endio(bio);
1354	}
1355}
1356
1357static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data *pkt)
1358{
1359	pkt_dbg(2, pd, "pkt %d\n", pkt->id);
1360
1361	for (;;) {
1362		switch (pkt->state) {
1363		case PACKET_WAITING_STATE:
1364			if ((pkt->write_size < pkt->frames) && (pkt->sleep_time > 0))
1365				return;
1366
1367			pkt->sleep_time = 0;
1368			pkt_gather_data(pd, pkt);
1369			pkt_set_state(pkt, PACKET_READ_WAIT_STATE);
1370			break;
1371
1372		case PACKET_READ_WAIT_STATE:
1373			if (atomic_read(&pkt->io_wait) > 0)
1374				return;
1375
1376			if (atomic_read(&pkt->io_errors) > 0) {
1377				pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1378			} else {
1379				pkt_start_write(pd, pkt);
1380			}
1381			break;
1382
1383		case PACKET_WRITE_WAIT_STATE:
1384			if (atomic_read(&pkt->io_wait) > 0)
1385				return;
1386
1387			if (!pkt->w_bio->bi_error) {
1388				pkt_set_state(pkt, PACKET_FINISHED_STATE);
1389			} else {
1390				pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1391			}
1392			break;
1393
1394		case PACKET_RECOVERY_STATE:
1395			if (pkt_start_recovery(pkt)) {
1396				pkt_start_write(pd, pkt);
1397			} else {
1398				pkt_dbg(2, pd, "No recovery possible\n");
1399				pkt_set_state(pkt, PACKET_FINISHED_STATE);
1400			}
1401			break;
1402
1403		case PACKET_FINISHED_STATE:
1404			pkt_finish_packet(pkt, pkt->w_bio->bi_error);
1405			return;
1406
1407		default:
1408			BUG();
1409			break;
1410		}
1411	}
1412}
1413
1414static void pkt_handle_packets(struct pktcdvd_device *pd)
1415{
1416	struct packet_data *pkt, *next;
1417
1418	/*
1419	 * Run state machine for active packets
1420	 */
1421	list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1422		if (atomic_read(&pkt->run_sm) > 0) {
1423			atomic_set(&pkt->run_sm, 0);
1424			pkt_run_state_machine(pd, pkt);
1425		}
1426	}
1427
1428	/*
1429	 * Move no longer active packets to the free list
1430	 */
1431	spin_lock(&pd->cdrw.active_list_lock);
1432	list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_active_list, list) {
1433		if (pkt->state == PACKET_FINISHED_STATE) {
1434			list_del(&pkt->list);
1435			pkt_put_packet_data(pd, pkt);
1436			pkt_set_state(pkt, PACKET_IDLE_STATE);
1437			atomic_set(&pd->scan_queue, 1);
1438		}
1439	}
1440	spin_unlock(&pd->cdrw.active_list_lock);
1441}
1442
1443static void pkt_count_states(struct pktcdvd_device *pd, int *states)
1444{
1445	struct packet_data *pkt;
1446	int i;
1447
1448	for (i = 0; i < PACKET_NUM_STATES; i++)
1449		states[i] = 0;
1450
1451	spin_lock(&pd->cdrw.active_list_lock);
1452	list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1453		states[pkt->state]++;
1454	}
1455	spin_unlock(&pd->cdrw.active_list_lock);
1456}
1457
1458/*
1459 * kcdrwd is woken up when writes have been queued for one of our
1460 * registered devices
1461 */
1462static int kcdrwd(void *foobar)
1463{
1464	struct pktcdvd_device *pd = foobar;
1465	struct packet_data *pkt;
1466	long min_sleep_time, residue;
1467
1468	set_user_nice(current, MIN_NICE);
1469	set_freezable();
1470
1471	for (;;) {
1472		DECLARE_WAITQUEUE(wait, current);
1473
1474		/*
1475		 * Wait until there is something to do
1476		 */
1477		add_wait_queue(&pd->wqueue, &wait);
1478		for (;;) {
1479			set_current_state(TASK_INTERRUPTIBLE);
1480
1481			/* Check if we need to run pkt_handle_queue */
1482			if (atomic_read(&pd->scan_queue) > 0)
1483				goto work_to_do;
1484
1485			/* Check if we need to run the state machine for some packet */
1486			list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1487				if (atomic_read(&pkt->run_sm) > 0)
1488					goto work_to_do;
1489			}
1490
1491			/* Check if we need to process the iosched queues */
1492			if (atomic_read(&pd->iosched.attention) != 0)
1493				goto work_to_do;
1494
1495			/* Otherwise, go to sleep */
1496			if (PACKET_DEBUG > 1) {
1497				int states[PACKET_NUM_STATES];
1498				pkt_count_states(pd, states);
1499				pkt_dbg(2, pd, "i:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
1500					states[0], states[1], states[2],
1501					states[3], states[4], states[5]);
1502			}
1503
1504			min_sleep_time = MAX_SCHEDULE_TIMEOUT;
1505			list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1506				if (pkt->sleep_time && pkt->sleep_time < min_sleep_time)
1507					min_sleep_time = pkt->sleep_time;
1508			}
1509
1510			pkt_dbg(2, pd, "sleeping\n");
1511			residue = schedule_timeout(min_sleep_time);
1512			pkt_dbg(2, pd, "wake up\n");
1513
1514			/* make swsusp happy with our thread */
1515			try_to_freeze();
1516
1517			list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1518				if (!pkt->sleep_time)
1519					continue;
1520				pkt->sleep_time -= min_sleep_time - residue;
1521				if (pkt->sleep_time <= 0) {
1522					pkt->sleep_time = 0;
1523					atomic_inc(&pkt->run_sm);
1524				}
1525			}
1526
1527			if (kthread_should_stop())
1528				break;
1529		}
1530work_to_do:
1531		set_current_state(TASK_RUNNING);
1532		remove_wait_queue(&pd->wqueue, &wait);
1533
1534		if (kthread_should_stop())
1535			break;
1536
1537		/*
1538		 * if pkt_handle_queue returns true, we can queue
1539		 * another request.
1540		 */
1541		while (pkt_handle_queue(pd))
1542			;
1543
1544		/*
1545		 * Handle packet state machine
1546		 */
1547		pkt_handle_packets(pd);
1548
1549		/*
1550		 * Handle iosched queues
1551		 */
1552		pkt_iosched_process_queue(pd);
1553	}
1554
1555	return 0;
1556}
1557
1558static void pkt_print_settings(struct pktcdvd_device *pd)
1559{
1560	pkt_info(pd, "%s packets, %u blocks, Mode-%c disc\n",
1561		 pd->settings.fp ? "Fixed" : "Variable",
1562		 pd->settings.size >> 2,
1563		 pd->settings.block_mode == 8 ? '1' : '2');
1564}
1565
1566static int pkt_mode_sense(struct pktcdvd_device *pd, struct packet_command *cgc, int page_code, int page_control)
1567{
1568	memset(cgc->cmd, 0, sizeof(cgc->cmd));
1569
1570	cgc->cmd[0] = GPCMD_MODE_SENSE_10;
1571	cgc->cmd[2] = page_code | (page_control << 6);
1572	cgc->cmd[7] = cgc->buflen >> 8;
1573	cgc->cmd[8] = cgc->buflen & 0xff;
1574	cgc->data_direction = CGC_DATA_READ;
1575	return pkt_generic_packet(pd, cgc);
1576}
1577
1578static int pkt_mode_select(struct pktcdvd_device *pd, struct packet_command *cgc)
1579{
1580	memset(cgc->cmd, 0, sizeof(cgc->cmd));
1581	memset(cgc->buffer, 0, 2);
1582	cgc->cmd[0] = GPCMD_MODE_SELECT_10;
1583	cgc->cmd[1] = 0x10;		/* PF */
1584	cgc->cmd[7] = cgc->buflen >> 8;
1585	cgc->cmd[8] = cgc->buflen & 0xff;
1586	cgc->data_direction = CGC_DATA_WRITE;
1587	return pkt_generic_packet(pd, cgc);
1588}
1589
1590static int pkt_get_disc_info(struct pktcdvd_device *pd, disc_information *di)
1591{
1592	struct packet_command cgc;
1593	int ret;
1594
1595	/* set up command and get the disc info */
1596	init_cdrom_command(&cgc, di, sizeof(*di), CGC_DATA_READ);
1597	cgc.cmd[0] = GPCMD_READ_DISC_INFO;
1598	cgc.cmd[8] = cgc.buflen = 2;
1599	cgc.quiet = 1;
1600
1601	if ((ret = pkt_generic_packet(pd, &cgc)))
1602		return ret;
1603
1604	/* not all drives have the same disc_info length, so requeue
1605	 * packet with the length the drive tells us it can supply
1606	 */
1607	cgc.buflen = be16_to_cpu(di->disc_information_length) +
1608		     sizeof(di->disc_information_length);
1609
1610	if (cgc.buflen > sizeof(disc_information))
1611		cgc.buflen = sizeof(disc_information);
1612
1613	cgc.cmd[8] = cgc.buflen;
1614	return pkt_generic_packet(pd, &cgc);
1615}
1616
1617static int pkt_get_track_info(struct pktcdvd_device *pd, __u16 track, __u8 type, track_information *ti)
1618{
1619	struct packet_command cgc;
1620	int ret;
1621
1622	init_cdrom_command(&cgc, ti, 8, CGC_DATA_READ);
1623	cgc.cmd[0] = GPCMD_READ_TRACK_RZONE_INFO;
1624	cgc.cmd[1] = type & 3;
1625	cgc.cmd[4] = (track & 0xff00) >> 8;
1626	cgc.cmd[5] = track & 0xff;
1627	cgc.cmd[8] = 8;
1628	cgc.quiet = 1;
1629
1630	if ((ret = pkt_generic_packet(pd, &cgc)))
1631		return ret;
1632
1633	cgc.buflen = be16_to_cpu(ti->track_information_length) +
1634		     sizeof(ti->track_information_length);
1635
1636	if (cgc.buflen > sizeof(track_information))
1637		cgc.buflen = sizeof(track_information);
1638
1639	cgc.cmd[8] = cgc.buflen;
1640	return pkt_generic_packet(pd, &cgc);
1641}
1642
1643static noinline_for_stack int pkt_get_last_written(struct pktcdvd_device *pd,
1644						long *last_written)
1645{
1646	disc_information di;
1647	track_information ti;
1648	__u32 last_track;
1649	int ret = -1;
1650
1651	if ((ret = pkt_get_disc_info(pd, &di)))
1652		return ret;
1653
1654	last_track = (di.last_track_msb << 8) | di.last_track_lsb;
1655	if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1656		return ret;
1657
1658	/* if this track is blank, try the previous. */
1659	if (ti.blank) {
1660		last_track--;
1661		if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1662			return ret;
1663	}
1664
1665	/* if last recorded field is valid, return it. */
1666	if (ti.lra_v) {
1667		*last_written = be32_to_cpu(ti.last_rec_address);
1668	} else {
1669		/* make it up instead */
1670		*last_written = be32_to_cpu(ti.track_start) +
1671				be32_to_cpu(ti.track_size);
1672		if (ti.free_blocks)
1673			*last_written -= (be32_to_cpu(ti.free_blocks) + 7);
1674	}
1675	return 0;
1676}
1677
1678/*
1679 * write mode select package based on pd->settings
1680 */
1681static noinline_for_stack int pkt_set_write_settings(struct pktcdvd_device *pd)
1682{
1683	struct packet_command cgc;
1684	struct request_sense sense;
1685	write_param_page *wp;
1686	char buffer[128];
1687	int ret, size;
1688
1689	/* doesn't apply to DVD+RW or DVD-RAM */
1690	if ((pd->mmc3_profile == 0x1a) || (pd->mmc3_profile == 0x12))
1691		return 0;
1692
1693	memset(buffer, 0, sizeof(buffer));
1694	init_cdrom_command(&cgc, buffer, sizeof(*wp), CGC_DATA_READ);
1695	cgc.sense = &sense;
1696	if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1697		pkt_dump_sense(pd, &cgc);
1698		return ret;
1699	}
1700
1701	size = 2 + ((buffer[0] << 8) | (buffer[1] & 0xff));
1702	pd->mode_offset = (buffer[6] << 8) | (buffer[7] & 0xff);
1703	if (size > sizeof(buffer))
1704		size = sizeof(buffer);
1705
1706	/*
1707	 * now get it all
1708	 */
1709	init_cdrom_command(&cgc, buffer, size, CGC_DATA_READ);
1710	cgc.sense = &sense;
1711	if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1712		pkt_dump_sense(pd, &cgc);
1713		return ret;
1714	}
1715
1716	/*
1717	 * write page is offset header + block descriptor length
1718	 */
1719	wp = (write_param_page *) &buffer[sizeof(struct mode_page_header) + pd->mode_offset];
1720
1721	wp->fp = pd->settings.fp;
1722	wp->track_mode = pd->settings.track_mode;
1723	wp->write_type = pd->settings.write_type;
1724	wp->data_block_type = pd->settings.block_mode;
1725
1726	wp->multi_session = 0;
1727
1728#ifdef PACKET_USE_LS
1729	wp->link_size = 7;
1730	wp->ls_v = 1;
1731#endif
1732
1733	if (wp->data_block_type == PACKET_BLOCK_MODE1) {
1734		wp->session_format = 0;
1735		wp->subhdr2 = 0x20;
1736	} else if (wp->data_block_type == PACKET_BLOCK_MODE2) {
1737		wp->session_format = 0x20;
1738		wp->subhdr2 = 8;
1739#if 0
1740		wp->mcn[0] = 0x80;
1741		memcpy(&wp->mcn[1], PACKET_MCN, sizeof(wp->mcn) - 1);
1742#endif
1743	} else {
1744		/*
1745		 * paranoia
1746		 */
1747		pkt_err(pd, "write mode wrong %d\n", wp->data_block_type);
1748		return 1;
1749	}
1750	wp->packet_size = cpu_to_be32(pd->settings.size >> 2);
1751
1752	cgc.buflen = cgc.cmd[8] = size;
1753	if ((ret = pkt_mode_select(pd, &cgc))) {
1754		pkt_dump_sense(pd, &cgc);
1755		return ret;
1756	}
1757
1758	pkt_print_settings(pd);
1759	return 0;
1760}
1761
1762/*
1763 * 1 -- we can write to this track, 0 -- we can't
1764 */
1765static int pkt_writable_track(struct pktcdvd_device *pd, track_information *ti)
1766{
1767	switch (pd->mmc3_profile) {
1768		case 0x1a: /* DVD+RW */
1769		case 0x12: /* DVD-RAM */
1770			/* The track is always writable on DVD+RW/DVD-RAM */
1771			return 1;
1772		default:
1773			break;
1774	}
1775
1776	if (!ti->packet || !ti->fp)
1777		return 0;
1778
1779	/*
1780	 * "good" settings as per Mt Fuji.
1781	 */
1782	if (ti->rt == 0 && ti->blank == 0)
1783		return 1;
1784
1785	if (ti->rt == 0 && ti->blank == 1)
1786		return 1;
1787
1788	if (ti->rt == 1 && ti->blank == 0)
1789		return 1;
1790
1791	pkt_err(pd, "bad state %d-%d-%d\n", ti->rt, ti->blank, ti->packet);
1792	return 0;
1793}
1794
1795/*
1796 * 1 -- we can write to this disc, 0 -- we can't
1797 */
1798static int pkt_writable_disc(struct pktcdvd_device *pd, disc_information *di)
1799{
1800	switch (pd->mmc3_profile) {
1801		case 0x0a: /* CD-RW */
1802		case 0xffff: /* MMC3 not supported */
1803			break;
1804		case 0x1a: /* DVD+RW */
1805		case 0x13: /* DVD-RW */
1806		case 0x12: /* DVD-RAM */
1807			return 1;
1808		default:
1809			pkt_dbg(2, pd, "Wrong disc profile (%x)\n",
1810				pd->mmc3_profile);
1811			return 0;
1812	}
1813
1814	/*
1815	 * for disc type 0xff we should probably reserve a new track.
1816	 * but i'm not sure, should we leave this to user apps? probably.
1817	 */
1818	if (di->disc_type == 0xff) {
1819		pkt_notice(pd, "unknown disc - no track?\n");
1820		return 0;
1821	}
1822
1823	if (di->disc_type != 0x20 && di->disc_type != 0) {
1824		pkt_err(pd, "wrong disc type (%x)\n", di->disc_type);
1825		return 0;
1826	}
1827
1828	if (di->erasable == 0) {
1829		pkt_notice(pd, "disc not erasable\n");
1830		return 0;
1831	}
1832
1833	if (di->border_status == PACKET_SESSION_RESERVED) {
1834		pkt_err(pd, "can't write to last track (reserved)\n");
1835		return 0;
1836	}
1837
1838	return 1;
1839}
1840
1841static noinline_for_stack int pkt_probe_settings(struct pktcdvd_device *pd)
1842{
1843	struct packet_command cgc;
1844	unsigned char buf[12];
1845	disc_information di;
1846	track_information ti;
1847	int ret, track;
1848
1849	init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1850	cgc.cmd[0] = GPCMD_GET_CONFIGURATION;
1851	cgc.cmd[8] = 8;
1852	ret = pkt_generic_packet(pd, &cgc);
1853	pd->mmc3_profile = ret ? 0xffff : buf[6] << 8 | buf[7];
1854
1855	memset(&di, 0, sizeof(disc_information));
1856	memset(&ti, 0, sizeof(track_information));
1857
1858	if ((ret = pkt_get_disc_info(pd, &di))) {
1859		pkt_err(pd, "failed get_disc\n");
1860		return ret;
1861	}
1862
1863	if (!pkt_writable_disc(pd, &di))
1864		return -EROFS;
1865
1866	pd->type = di.erasable ? PACKET_CDRW : PACKET_CDR;
1867
1868	track = 1; /* (di.last_track_msb << 8) | di.last_track_lsb; */
1869	if ((ret = pkt_get_track_info(pd, track, 1, &ti))) {
1870		pkt_err(pd, "failed get_track\n");
1871		return ret;
1872	}
1873
1874	if (!pkt_writable_track(pd, &ti)) {
1875		pkt_err(pd, "can't write to this track\n");
1876		return -EROFS;
1877	}
1878
1879	/*
1880	 * we keep packet size in 512 byte units, makes it easier to
1881	 * deal with request calculations.
1882	 */
1883	pd->settings.size = be32_to_cpu(ti.fixed_packet_size) << 2;
1884	if (pd->settings.size == 0) {
1885		pkt_notice(pd, "detected zero packet size!\n");
1886		return -ENXIO;
1887	}
1888	if (pd->settings.size > PACKET_MAX_SECTORS) {
1889		pkt_err(pd, "packet size is too big\n");
1890		return -EROFS;
1891	}
1892	pd->settings.fp = ti.fp;
1893	pd->offset = (be32_to_cpu(ti.track_start) << 2) & (pd->settings.size - 1);
1894
1895	if (ti.nwa_v) {
1896		pd->nwa = be32_to_cpu(ti.next_writable);
1897		set_bit(PACKET_NWA_VALID, &pd->flags);
1898	}
1899
1900	/*
1901	 * in theory we could use lra on -RW media as well and just zero
1902	 * blocks that haven't been written yet, but in practice that
1903	 * is just a no-go. we'll use that for -R, naturally.
1904	 */
1905	if (ti.lra_v) {
1906		pd->lra = be32_to_cpu(ti.last_rec_address);
1907		set_bit(PACKET_LRA_VALID, &pd->flags);
1908	} else {
1909		pd->lra = 0xffffffff;
1910		set_bit(PACKET_LRA_VALID, &pd->flags);
1911	}
1912
1913	/*
1914	 * fine for now
1915	 */
1916	pd->settings.link_loss = 7;
1917	pd->settings.write_type = 0;	/* packet */
1918	pd->settings.track_mode = ti.track_mode;
1919
1920	/*
1921	 * mode1 or mode2 disc
1922	 */
1923	switch (ti.data_mode) {
1924		case PACKET_MODE1:
1925			pd->settings.block_mode = PACKET_BLOCK_MODE1;
1926			break;
1927		case PACKET_MODE2:
1928			pd->settings.block_mode = PACKET_BLOCK_MODE2;
1929			break;
1930		default:
1931			pkt_err(pd, "unknown data mode\n");
1932			return -EROFS;
1933	}
1934	return 0;
1935}
1936
1937/*
1938 * enable/disable write caching on drive
1939 */
1940static noinline_for_stack int pkt_write_caching(struct pktcdvd_device *pd,
1941						int set)
1942{
1943	struct packet_command cgc;
1944	struct request_sense sense;
1945	unsigned char buf[64];
1946	int ret;
1947
1948	init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1949	cgc.sense = &sense;
1950	cgc.buflen = pd->mode_offset + 12;
1951
1952	/*
1953	 * caching mode page might not be there, so quiet this command
1954	 */
1955	cgc.quiet = 1;
1956
1957	if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0)))
1958		return ret;
1959
1960	buf[pd->mode_offset + 10] |= (!!set << 2);
1961
1962	cgc.buflen = cgc.cmd[8] = 2 + ((buf[0] << 8) | (buf[1] & 0xff));
1963	ret = pkt_mode_select(pd, &cgc);
1964	if (ret) {
1965		pkt_err(pd, "write caching control failed\n");
1966		pkt_dump_sense(pd, &cgc);
1967	} else if (!ret && set)
1968		pkt_notice(pd, "enabled write caching\n");
1969	return ret;
1970}
1971
1972static int pkt_lock_door(struct pktcdvd_device *pd, int lockflag)
1973{
1974	struct packet_command cgc;
1975
1976	init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
1977	cgc.cmd[0] = GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL;
1978	cgc.cmd[4] = lockflag ? 1 : 0;
1979	return pkt_generic_packet(pd, &cgc);
1980}
1981
1982/*
1983 * Returns drive maximum write speed
1984 */
1985static noinline_for_stack int pkt_get_max_speed(struct pktcdvd_device *pd,
1986						unsigned *write_speed)
1987{
1988	struct packet_command cgc;
1989	struct request_sense sense;
1990	unsigned char buf[256+18];
1991	unsigned char *cap_buf;
1992	int ret, offset;
1993
1994	cap_buf = &buf[sizeof(struct mode_page_header) + pd->mode_offset];
1995	init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_UNKNOWN);
1996	cgc.sense = &sense;
1997
1998	ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1999	if (ret) {
2000		cgc.buflen = pd->mode_offset + cap_buf[1] + 2 +
2001			     sizeof(struct mode_page_header);
2002		ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
2003		if (ret) {
2004			pkt_dump_sense(pd, &cgc);
2005			return ret;
2006		}
2007	}
2008
2009	offset = 20;			    /* Obsoleted field, used by older drives */
2010	if (cap_buf[1] >= 28)
2011		offset = 28;		    /* Current write speed selected */
2012	if (cap_buf[1] >= 30) {
2013		/* If the drive reports at least one "Logical Unit Write
2014		 * Speed Performance Descriptor Block", use the information
2015		 * in the first block. (contains the highest speed)
2016		 */
2017		int num_spdb = (cap_buf[30] << 8) + cap_buf[31];
2018		if (num_spdb > 0)
2019			offset = 34;
2020	}
2021
2022	*write_speed = (cap_buf[offset] << 8) | cap_buf[offset + 1];
2023	return 0;
2024}
2025
2026/* These tables from cdrecord - I don't have orange book */
2027/* standard speed CD-RW (1-4x) */
2028static char clv_to_speed[16] = {
2029	/* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2030	   0, 2, 4, 6, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2031};
2032/* high speed CD-RW (-10x) */
2033static char hs_clv_to_speed[16] = {
2034	/* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2035	   0, 2, 4, 6, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2036};
2037/* ultra high speed CD-RW */
2038static char us_clv_to_speed[16] = {
2039	/* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2040	   0, 2, 4, 8, 0, 0,16, 0,24,32,40,48, 0, 0, 0, 0
2041};
2042
2043/*
2044 * reads the maximum media speed from ATIP
2045 */
2046static noinline_for_stack int pkt_media_speed(struct pktcdvd_device *pd,
2047						unsigned *speed)
2048{
2049	struct packet_command cgc;
2050	struct request_sense sense;
2051	unsigned char buf[64];
2052	unsigned int size, st, sp;
2053	int ret;
2054
2055	init_cdrom_command(&cgc, buf, 2, CGC_DATA_READ);
2056	cgc.sense = &sense;
2057	cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2058	cgc.cmd[1] = 2;
2059	cgc.cmd[2] = 4; /* READ ATIP */
2060	cgc.cmd[8] = 2;
2061	ret = pkt_generic_packet(pd, &cgc);
2062	if (ret) {
2063		pkt_dump_sense(pd, &cgc);
2064		return ret;
2065	}
2066	size = ((unsigned int) buf[0]<<8) + buf[1] + 2;
2067	if (size > sizeof(buf))
2068		size = sizeof(buf);
2069
2070	init_cdrom_command(&cgc, buf, size, CGC_DATA_READ);
2071	cgc.sense = &sense;
2072	cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2073	cgc.cmd[1] = 2;
2074	cgc.cmd[2] = 4;
2075	cgc.cmd[8] = size;
2076	ret = pkt_generic_packet(pd, &cgc);
2077	if (ret) {
2078		pkt_dump_sense(pd, &cgc);
2079		return ret;
2080	}
2081
2082	if (!(buf[6] & 0x40)) {
2083		pkt_notice(pd, "disc type is not CD-RW\n");
2084		return 1;
2085	}
2086	if (!(buf[6] & 0x4)) {
2087		pkt_notice(pd, "A1 values on media are not valid, maybe not CDRW?\n");
2088		return 1;
2089	}
2090
2091	st = (buf[6] >> 3) & 0x7; /* disc sub-type */
2092
2093	sp = buf[16] & 0xf; /* max speed from ATIP A1 field */
2094
2095	/* Info from cdrecord */
2096	switch (st) {
2097		case 0: /* standard speed */
2098			*speed = clv_to_speed[sp];
2099			break;
2100		case 1: /* high speed */
2101			*speed = hs_clv_to_speed[sp];
2102			break;
2103		case 2: /* ultra high speed */
2104			*speed = us_clv_to_speed[sp];
2105			break;
2106		default:
2107			pkt_notice(pd, "unknown disc sub-type %d\n", st);
2108			return 1;
2109	}
2110	if (*speed) {
2111		pkt_info(pd, "maximum media speed: %d\n", *speed);
2112		return 0;
2113	} else {
2114		pkt_notice(pd, "unknown speed %d for sub-type %d\n", sp, st);
2115		return 1;
2116	}
2117}
2118
2119static noinline_for_stack int pkt_perform_opc(struct pktcdvd_device *pd)
2120{
2121	struct packet_command cgc;
2122	struct request_sense sense;
2123	int ret;
2124
2125	pkt_dbg(2, pd, "Performing OPC\n");
2126
2127	init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2128	cgc.sense = &sense;
2129	cgc.timeout = 60*HZ;
2130	cgc.cmd[0] = GPCMD_SEND_OPC;
2131	cgc.cmd[1] = 1;
2132	if ((ret = pkt_generic_packet(pd, &cgc)))
2133		pkt_dump_sense(pd, &cgc);
2134	return ret;
2135}
2136
2137static int pkt_open_write(struct pktcdvd_device *pd)
2138{
2139	int ret;
2140	unsigned int write_speed, media_write_speed, read_speed;
2141
2142	if ((ret = pkt_probe_settings(pd))) {
2143		pkt_dbg(2, pd, "failed probe\n");
2144		return ret;
2145	}
2146
2147	if ((ret = pkt_set_write_settings(pd))) {
2148		pkt_dbg(1, pd, "failed saving write settings\n");
2149		return -EIO;
2150	}
2151
2152	pkt_write_caching(pd, USE_WCACHING);
2153
2154	if ((ret = pkt_get_max_speed(pd, &write_speed)))
2155		write_speed = 16 * 177;
2156	switch (pd->mmc3_profile) {
2157		case 0x13: /* DVD-RW */
2158		case 0x1a: /* DVD+RW */
2159		case 0x12: /* DVD-RAM */
2160			pkt_dbg(1, pd, "write speed %ukB/s\n", write_speed);
2161			break;
2162		default:
2163			if ((ret = pkt_media_speed(pd, &media_write_speed)))
2164				media_write_speed = 16;
2165			write_speed = min(write_speed, media_write_speed * 177);
2166			pkt_dbg(1, pd, "write speed %ux\n", write_speed / 176);
2167			break;
2168	}
2169	read_speed = write_speed;
2170
2171	if ((ret = pkt_set_speed(pd, write_speed, read_speed))) {
2172		pkt_dbg(1, pd, "couldn't set write speed\n");
2173		return -EIO;
2174	}
2175	pd->write_speed = write_speed;
2176	pd->read_speed = read_speed;
2177
2178	if ((ret = pkt_perform_opc(pd))) {
2179		pkt_dbg(1, pd, "Optimum Power Calibration failed\n");
2180	}
2181
2182	return 0;
2183}
2184
2185/*
2186 * called at open time.
2187 */
2188static int pkt_open_dev(struct pktcdvd_device *pd, fmode_t write)
2189{
2190	int ret;
2191	long lba;
2192	struct request_queue *q;
2193
2194	/*
2195	 * We need to re-open the cdrom device without O_NONBLOCK to be able
2196	 * to read/write from/to it. It is already opened in O_NONBLOCK mode
2197	 * so bdget() can't fail.
2198	 */
2199	bdget(pd->bdev->bd_dev);
2200	if ((ret = blkdev_get(pd->bdev, FMODE_READ | FMODE_EXCL, pd)))
2201		goto out;
2202
2203	if ((ret = pkt_get_last_written(pd, &lba))) {
2204		pkt_err(pd, "pkt_get_last_written failed\n");
2205		goto out_putdev;
2206	}
2207
2208	set_capacity(pd->disk, lba << 2);
2209	set_capacity(pd->bdev->bd_disk, lba << 2);
2210	bd_set_size(pd->bdev, (loff_t)lba << 11);
2211
2212	q = bdev_get_queue(pd->bdev);
2213	if (write) {
2214		if ((ret = pkt_open_write(pd)))
2215			goto out_putdev;
2216		/*
2217		 * Some CDRW drives can not handle writes larger than one packet,
2218		 * even if the size is a multiple of the packet size.
2219		 */
2220		spin_lock_irq(q->queue_lock);
2221		blk_queue_max_hw_sectors(q, pd->settings.size);
2222		spin_unlock_irq(q->queue_lock);
2223		set_bit(PACKET_WRITABLE, &pd->flags);
2224	} else {
2225		pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2226		clear_bit(PACKET_WRITABLE, &pd->flags);
2227	}
2228
2229	if ((ret = pkt_set_segment_merging(pd, q)))
2230		goto out_putdev;
2231
2232	if (write) {
2233		if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
2234			pkt_err(pd, "not enough memory for buffers\n");
2235			ret = -ENOMEM;
2236			goto out_putdev;
2237		}
2238		pkt_info(pd, "%lukB available on disc\n", lba << 1);
2239	}
2240
2241	return 0;
2242
2243out_putdev:
2244	blkdev_put(pd->bdev, FMODE_READ | FMODE_EXCL);
2245out:
2246	return ret;
2247}
2248
2249/*
2250 * called when the device is closed. makes sure that the device flushes
2251 * the internal cache before we close.
2252 */
2253static void pkt_release_dev(struct pktcdvd_device *pd, int flush)
2254{
2255	if (flush && pkt_flush_cache(pd))
2256		pkt_dbg(1, pd, "not flushing cache\n");
2257
2258	pkt_lock_door(pd, 0);
2259
2260	pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2261	blkdev_put(pd->bdev, FMODE_READ | FMODE_EXCL);
2262
2263	pkt_shrink_pktlist(pd);
2264}
2265
2266static struct pktcdvd_device *pkt_find_dev_from_minor(unsigned int dev_minor)
2267{
2268	if (dev_minor >= MAX_WRITERS)
2269		return NULL;
2270	return pkt_devs[dev_minor];
2271}
2272
2273static int pkt_open(struct block_device *bdev, fmode_t mode)
2274{
2275	struct pktcdvd_device *pd = NULL;
2276	int ret;
2277
2278	mutex_lock(&pktcdvd_mutex);
2279	mutex_lock(&ctl_mutex);
2280	pd = pkt_find_dev_from_minor(MINOR(bdev->bd_dev));
2281	if (!pd) {
2282		ret = -ENODEV;
2283		goto out;
2284	}
2285	BUG_ON(pd->refcnt < 0);
2286
2287	pd->refcnt++;
2288	if (pd->refcnt > 1) {
2289		if ((mode & FMODE_WRITE) &&
2290		    !test_bit(PACKET_WRITABLE, &pd->flags)) {
2291			ret = -EBUSY;
2292			goto out_dec;
2293		}
2294	} else {
2295		ret = pkt_open_dev(pd, mode & FMODE_WRITE);
2296		if (ret)
2297			goto out_dec;
2298		/*
2299		 * needed here as well, since ext2 (among others) may change
2300		 * the blocksize at mount time
2301		 */
2302		set_blocksize(bdev, CD_FRAMESIZE);
2303	}
2304
2305	mutex_unlock(&ctl_mutex);
2306	mutex_unlock(&pktcdvd_mutex);
2307	return 0;
2308
2309out_dec:
2310	pd->refcnt--;
2311out:
2312	mutex_unlock(&ctl_mutex);
2313	mutex_unlock(&pktcdvd_mutex);
2314	return ret;
2315}
2316
2317static void pkt_close(struct gendisk *disk, fmode_t mode)
2318{
2319	struct pktcdvd_device *pd = disk->private_data;
2320
2321	mutex_lock(&pktcdvd_mutex);
2322	mutex_lock(&ctl_mutex);
2323	pd->refcnt--;
2324	BUG_ON(pd->refcnt < 0);
2325	if (pd->refcnt == 0) {
2326		int flush = test_bit(PACKET_WRITABLE, &pd->flags);
2327		pkt_release_dev(pd, flush);
2328	}
2329	mutex_unlock(&ctl_mutex);
2330	mutex_unlock(&pktcdvd_mutex);
2331}
2332
2333
2334static void pkt_end_io_read_cloned(struct bio *bio)
2335{
2336	struct packet_stacked_data *psd = bio->bi_private;
2337	struct pktcdvd_device *pd = psd->pd;
2338
2339	psd->bio->bi_error = bio->bi_error;
2340	bio_put(bio);
2341	bio_endio(psd->bio);
2342	mempool_free(psd, psd_pool);
2343	pkt_bio_finished(pd);
2344}
2345
2346static void pkt_make_request_read(struct pktcdvd_device *pd, struct bio *bio)
2347{
2348	struct bio *cloned_bio = bio_clone(bio, GFP_NOIO);
2349	struct packet_stacked_data *psd = mempool_alloc(psd_pool, GFP_NOIO);
2350
2351	psd->pd = pd;
2352	psd->bio = bio;
2353	cloned_bio->bi_bdev = pd->bdev;
2354	cloned_bio->bi_private = psd;
2355	cloned_bio->bi_end_io = pkt_end_io_read_cloned;
2356	pd->stats.secs_r += bio_sectors(bio);
2357	pkt_queue_bio(pd, cloned_bio);
2358}
2359
2360static void pkt_make_request_write(struct request_queue *q, struct bio *bio)
2361{
2362	struct pktcdvd_device *pd = q->queuedata;
2363	sector_t zone;
2364	struct packet_data *pkt;
2365	int was_empty, blocked_bio;
2366	struct pkt_rb_node *node;
2367
2368	zone = get_zone(bio->bi_iter.bi_sector, pd);
2369
2370	/*
2371	 * If we find a matching packet in state WAITING or READ_WAIT, we can
2372	 * just append this bio to that packet.
2373	 */
2374	spin_lock(&pd->cdrw.active_list_lock);
2375	blocked_bio = 0;
2376	list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
2377		if (pkt->sector == zone) {
2378			spin_lock(&pkt->lock);
2379			if ((pkt->state == PACKET_WAITING_STATE) ||
2380			    (pkt->state == PACKET_READ_WAIT_STATE)) {
2381				bio_list_add(&pkt->orig_bios, bio);
2382				pkt->write_size +=
2383					bio->bi_iter.bi_size / CD_FRAMESIZE;
2384				if ((pkt->write_size >= pkt->frames) &&
2385				    (pkt->state == PACKET_WAITING_STATE)) {
2386					atomic_inc(&pkt->run_sm);
2387					wake_up(&pd->wqueue);
2388				}
2389				spin_unlock(&pkt->lock);
2390				spin_unlock(&pd->cdrw.active_list_lock);
2391				return;
2392			} else {
2393				blocked_bio = 1;
2394			}
2395			spin_unlock(&pkt->lock);
2396		}
2397	}
2398	spin_unlock(&pd->cdrw.active_list_lock);
2399
2400 	/*
2401	 * Test if there is enough room left in the bio work queue
2402	 * (queue size >= congestion on mark).
2403	 * If not, wait till the work queue size is below the congestion off mark.
2404	 */
2405	spin_lock(&pd->lock);
2406	if (pd->write_congestion_on > 0
2407	    && pd->bio_queue_size >= pd->write_congestion_on) {
2408		set_bdi_congested(&q->backing_dev_info, BLK_RW_ASYNC);
2409		do {
2410			spin_unlock(&pd->lock);
2411			congestion_wait(BLK_RW_ASYNC, HZ);
2412			spin_lock(&pd->lock);
2413		} while(pd->bio_queue_size > pd->write_congestion_off);
2414	}
2415	spin_unlock(&pd->lock);
2416
2417	/*
2418	 * No matching packet found. Store the bio in the work queue.
2419	 */
2420	node = mempool_alloc(pd->rb_pool, GFP_NOIO);
2421	node->bio = bio;
2422	spin_lock(&pd->lock);
2423	BUG_ON(pd->bio_queue_size < 0);
2424	was_empty = (pd->bio_queue_size == 0);
2425	pkt_rbtree_insert(pd, node);
2426	spin_unlock(&pd->lock);
2427
2428	/*
2429	 * Wake up the worker thread.
2430	 */
2431	atomic_set(&pd->scan_queue, 1);
2432	if (was_empty) {
2433		/* This wake_up is required for correct operation */
2434		wake_up(&pd->wqueue);
2435	} else if (!list_empty(&pd->cdrw.pkt_free_list) && !blocked_bio) {
2436		/*
2437		 * This wake up is not required for correct operation,
2438		 * but improves performance in some cases.
2439		 */
2440		wake_up(&pd->wqueue);
2441	}
2442}
2443
2444static blk_qc_t pkt_make_request(struct request_queue *q, struct bio *bio)
2445{
2446	struct pktcdvd_device *pd;
2447	char b[BDEVNAME_SIZE];
2448	struct bio *split;
2449
2450	blk_queue_bounce(q, &bio);
2451
2452	blk_queue_split(q, &bio, q->bio_split);
2453
2454	pd = q->queuedata;
2455	if (!pd) {
2456		pr_err("%s incorrect request queue\n",
2457		       bdevname(bio->bi_bdev, b));
2458		goto end_io;
2459	}
2460
2461	pkt_dbg(2, pd, "start = %6llx stop = %6llx\n",
2462		(unsigned long long)bio->bi_iter.bi_sector,
2463		(unsigned long long)bio_end_sector(bio));
2464
2465	/*
2466	 * Clone READ bios so we can have our own bi_end_io callback.
2467	 */
2468	if (bio_data_dir(bio) == READ) {
2469		pkt_make_request_read(pd, bio);
2470		return BLK_QC_T_NONE;
2471	}
2472
2473	if (!test_bit(PACKET_WRITABLE, &pd->flags)) {
2474		pkt_notice(pd, "WRITE for ro device (%llu)\n",
2475			   (unsigned long long)bio->bi_iter.bi_sector);
2476		goto end_io;
2477	}
2478
2479	if (!bio->bi_iter.bi_size || (bio->bi_iter.bi_size % CD_FRAMESIZE)) {
2480		pkt_err(pd, "wrong bio size\n");
2481		goto end_io;
2482	}
2483
2484	do {
2485		sector_t zone = get_zone(bio->bi_iter.bi_sector, pd);
2486		sector_t last_zone = get_zone(bio_end_sector(bio) - 1, pd);
2487
2488		if (last_zone != zone) {
2489			BUG_ON(last_zone != zone + pd->settings.size);
2490
2491			split = bio_split(bio, last_zone -
2492					  bio->bi_iter.bi_sector,
2493					  GFP_NOIO, fs_bio_set);
2494			bio_chain(split, bio);
2495		} else {
2496			split = bio;
2497		}
2498
2499		pkt_make_request_write(q, split);
2500	} while (split != bio);
2501
2502	return BLK_QC_T_NONE;
2503end_io:
2504	bio_io_error(bio);
2505	return BLK_QC_T_NONE;
2506}
2507
2508static void pkt_init_queue(struct pktcdvd_device *pd)
2509{
2510	struct request_queue *q = pd->disk->queue;
2511
2512	blk_queue_make_request(q, pkt_make_request);
2513	blk_queue_logical_block_size(q, CD_FRAMESIZE);
2514	blk_queue_max_hw_sectors(q, PACKET_MAX_SECTORS);
2515	q->queuedata = pd;
2516}
2517
2518static int pkt_seq_show(struct seq_file *m, void *p)
2519{
2520	struct pktcdvd_device *pd = m->private;
2521	char *msg;
2522	char bdev_buf[BDEVNAME_SIZE];
2523	int states[PACKET_NUM_STATES];
2524
2525	seq_printf(m, "Writer %s mapped to %s:\n", pd->name,
2526		   bdevname(pd->bdev, bdev_buf));
2527
2528	seq_printf(m, "\nSettings:\n");
2529	seq_printf(m, "\tpacket size:\t\t%dkB\n", pd->settings.size / 2);
2530
2531	if (pd->settings.write_type == 0)
2532		msg = "Packet";
2533	else
2534		msg = "Unknown";
2535	seq_printf(m, "\twrite type:\t\t%s\n", msg);
2536
2537	seq_printf(m, "\tpacket type:\t\t%s\n", pd->settings.fp ? "Fixed" : "Variable");
2538	seq_printf(m, "\tlink loss:\t\t%d\n", pd->settings.link_loss);
2539
2540	seq_printf(m, "\ttrack mode:\t\t%d\n", pd->settings.track_mode);
2541
2542	if (pd->settings.block_mode == PACKET_BLOCK_MODE1)
2543		msg = "Mode 1";
2544	else if (pd->settings.block_mode == PACKET_BLOCK_MODE2)
2545		msg = "Mode 2";
2546	else
2547		msg = "Unknown";
2548	seq_printf(m, "\tblock mode:\t\t%s\n", msg);
2549
2550	seq_printf(m, "\nStatistics:\n");
2551	seq_printf(m, "\tpackets started:\t%lu\n", pd->stats.pkt_started);
2552	seq_printf(m, "\tpackets ended:\t\t%lu\n", pd->stats.pkt_ended);
2553	seq_printf(m, "\twritten:\t\t%lukB\n", pd->stats.secs_w >> 1);
2554	seq_printf(m, "\tread gather:\t\t%lukB\n", pd->stats.secs_rg >> 1);
2555	seq_printf(m, "\tread:\t\t\t%lukB\n", pd->stats.secs_r >> 1);
2556
2557	seq_printf(m, "\nMisc:\n");
2558	seq_printf(m, "\treference count:\t%d\n", pd->refcnt);
2559	seq_printf(m, "\tflags:\t\t\t0x%lx\n", pd->flags);
2560	seq_printf(m, "\tread speed:\t\t%ukB/s\n", pd->read_speed);
2561	seq_printf(m, "\twrite speed:\t\t%ukB/s\n", pd->write_speed);
2562	seq_printf(m, "\tstart offset:\t\t%lu\n", pd->offset);
2563	seq_printf(m, "\tmode page offset:\t%u\n", pd->mode_offset);
2564
2565	seq_printf(m, "\nQueue state:\n");
2566	seq_printf(m, "\tbios queued:\t\t%d\n", pd->bio_queue_size);
2567	seq_printf(m, "\tbios pending:\t\t%d\n", atomic_read(&pd->cdrw.pending_bios));
2568	seq_printf(m, "\tcurrent sector:\t\t0x%llx\n", (unsigned long long)pd->current_sector);
2569
2570	pkt_count_states(pd, states);
2571	seq_printf(m, "\tstate:\t\t\ti:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
2572		   states[0], states[1], states[2], states[3], states[4], states[5]);
2573
2574	seq_printf(m, "\twrite congestion marks:\toff=%d on=%d\n",
2575			pd->write_congestion_off,
2576			pd->write_congestion_on);
2577	return 0;
2578}
2579
2580static int pkt_seq_open(struct inode *inode, struct file *file)
2581{
2582	return single_open(file, pkt_seq_show, PDE_DATA(inode));
2583}
2584
2585static const struct file_operations pkt_proc_fops = {
2586	.open	= pkt_seq_open,
2587	.read	= seq_read,
2588	.llseek	= seq_lseek,
2589	.release = single_release
2590};
2591
2592static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
2593{
2594	int i;
2595	int ret = 0;
2596	char b[BDEVNAME_SIZE];
2597	struct block_device *bdev;
2598
2599	if (pd->pkt_dev == dev) {
2600		pkt_err(pd, "recursive setup not allowed\n");
2601		return -EBUSY;
2602	}
2603	for (i = 0; i < MAX_WRITERS; i++) {
2604		struct pktcdvd_device *pd2 = pkt_devs[i];
2605		if (!pd2)
2606			continue;
2607		if (pd2->bdev->bd_dev == dev) {
2608			pkt_err(pd, "%s already setup\n",
2609				bdevname(pd2->bdev, b));
2610			return -EBUSY;
2611		}
2612		if (pd2->pkt_dev == dev) {
2613			pkt_err(pd, "can't chain pktcdvd devices\n");
2614			return -EBUSY;
2615		}
2616	}
2617
2618	bdev = bdget(dev);
2619	if (!bdev)
2620		return -ENOMEM;
2621	ret = blkdev_get(bdev, FMODE_READ | FMODE_NDELAY, NULL);
2622	if (ret)
2623		return ret;
2624
2625	/* This is safe, since we have a reference from open(). */
2626	__module_get(THIS_MODULE);
2627
2628	pd->bdev = bdev;
2629	set_blocksize(bdev, CD_FRAMESIZE);
2630
2631	pkt_init_queue(pd);
2632
2633	atomic_set(&pd->cdrw.pending_bios, 0);
2634	pd->cdrw.thread = kthread_run(kcdrwd, pd, "%s", pd->name);
2635	if (IS_ERR(pd->cdrw.thread)) {
2636		pkt_err(pd, "can't start kernel thread\n");
2637		ret = -ENOMEM;
2638		goto out_mem;
2639	}
2640
2641	proc_create_data(pd->name, 0, pkt_proc, &pkt_proc_fops, pd);
2642	pkt_dbg(1, pd, "writer mapped to %s\n", bdevname(bdev, b));
2643	return 0;
2644
2645out_mem:
2646	blkdev_put(bdev, FMODE_READ | FMODE_NDELAY);
2647	/* This is safe: open() is still holding a reference. */
2648	module_put(THIS_MODULE);
2649	return ret;
2650}
2651
2652static int pkt_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg)
2653{
2654	struct pktcdvd_device *pd = bdev->bd_disk->private_data;
2655	int ret;
2656
2657	pkt_dbg(2, pd, "cmd %x, dev %d:%d\n",
2658		cmd, MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev));
2659
2660	mutex_lock(&pktcdvd_mutex);
2661	switch (cmd) {
2662	case CDROMEJECT:
2663		/*
2664		 * The door gets locked when the device is opened, so we
2665		 * have to unlock it or else the eject command fails.
2666		 */
2667		if (pd->refcnt == 1)
2668			pkt_lock_door(pd, 0);
2669		/* fallthru */
2670	/*
2671	 * forward selected CDROM ioctls to CD-ROM, for UDF
2672	 */
2673	case CDROMMULTISESSION:
2674	case CDROMREADTOCENTRY:
2675	case CDROM_LAST_WRITTEN:
2676	case CDROM_SEND_PACKET:
2677	case SCSI_IOCTL_SEND_COMMAND:
2678		ret = __blkdev_driver_ioctl(pd->bdev, mode, cmd, arg);
2679		break;
2680
2681	default:
2682		pkt_dbg(2, pd, "Unknown ioctl (%x)\n", cmd);
2683		ret = -ENOTTY;
2684	}
2685	mutex_unlock(&pktcdvd_mutex);
2686
2687	return ret;
2688}
2689
2690static unsigned int pkt_check_events(struct gendisk *disk,
2691				     unsigned int clearing)
2692{
2693	struct pktcdvd_device *pd = disk->private_data;
2694	struct gendisk *attached_disk;
2695
2696	if (!pd)
2697		return 0;
2698	if (!pd->bdev)
2699		return 0;
2700	attached_disk = pd->bdev->bd_disk;
2701	if (!attached_disk || !attached_disk->fops->check_events)
2702		return 0;
2703	return attached_disk->fops->check_events(attached_disk, clearing);
2704}
2705
2706static const struct block_device_operations pktcdvd_ops = {
2707	.owner =		THIS_MODULE,
2708	.open =			pkt_open,
2709	.release =		pkt_close,
2710	.ioctl =		pkt_ioctl,
2711	.check_events =		pkt_check_events,
2712};
2713
2714static char *pktcdvd_devnode(struct gendisk *gd, umode_t *mode)
2715{
2716	return kasprintf(GFP_KERNEL, "pktcdvd/%s", gd->disk_name);
2717}
2718
2719/*
2720 * Set up mapping from pktcdvd device to CD-ROM device.
2721 */
2722static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
2723{
2724	int idx;
2725	int ret = -ENOMEM;
2726	struct pktcdvd_device *pd;
2727	struct gendisk *disk;
2728
2729	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2730
2731	for (idx = 0; idx < MAX_WRITERS; idx++)
2732		if (!pkt_devs[idx])
2733			break;
2734	if (idx == MAX_WRITERS) {
2735		pr_err("max %d writers supported\n", MAX_WRITERS);
2736		ret = -EBUSY;
2737		goto out_mutex;
2738	}
2739
2740	pd = kzalloc(sizeof(struct pktcdvd_device), GFP_KERNEL);
2741	if (!pd)
2742		goto out_mutex;
2743
2744	pd->rb_pool = mempool_create_kmalloc_pool(PKT_RB_POOL_SIZE,
2745						  sizeof(struct pkt_rb_node));
2746	if (!pd->rb_pool)
2747		goto out_mem;
2748
2749	INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
2750	INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
2751	spin_lock_init(&pd->cdrw.active_list_lock);
2752
2753	spin_lock_init(&pd->lock);
2754	spin_lock_init(&pd->iosched.lock);
2755	bio_list_init(&pd->iosched.read_queue);
2756	bio_list_init(&pd->iosched.write_queue);
2757	sprintf(pd->name, DRIVER_NAME"%d", idx);
2758	init_waitqueue_head(&pd->wqueue);
2759	pd->bio_queue = RB_ROOT;
2760
2761	pd->write_congestion_on  = write_congestion_on;
2762	pd->write_congestion_off = write_congestion_off;
2763
2764	disk = alloc_disk(1);
2765	if (!disk)
2766		goto out_mem;
2767	pd->disk = disk;
2768	disk->major = pktdev_major;
2769	disk->first_minor = idx;
2770	disk->fops = &pktcdvd_ops;
2771	disk->flags = GENHD_FL_REMOVABLE;
2772	strcpy(disk->disk_name, pd->name);
2773	disk->devnode = pktcdvd_devnode;
2774	disk->private_data = pd;
2775	disk->queue = blk_alloc_queue(GFP_KERNEL);
2776	if (!disk->queue)
2777		goto out_mem2;
2778
2779	pd->pkt_dev = MKDEV(pktdev_major, idx);
2780	ret = pkt_new_dev(pd, dev);
2781	if (ret)
2782		goto out_new_dev;
2783
2784	/* inherit events of the host device */
2785	disk->events = pd->bdev->bd_disk->events;
2786	disk->async_events = pd->bdev->bd_disk->async_events;
2787
2788	add_disk(disk);
2789
2790	pkt_sysfs_dev_new(pd);
2791	pkt_debugfs_dev_new(pd);
2792
2793	pkt_devs[idx] = pd;
2794	if (pkt_dev)
2795		*pkt_dev = pd->pkt_dev;
2796
2797	mutex_unlock(&ctl_mutex);
2798	return 0;
2799
2800out_new_dev:
2801	blk_cleanup_queue(disk->queue);
2802out_mem2:
2803	put_disk(disk);
2804out_mem:
2805	mempool_destroy(pd->rb_pool);
2806	kfree(pd);
2807out_mutex:
2808	mutex_unlock(&ctl_mutex);
2809	pr_err("setup of pktcdvd device failed\n");
2810	return ret;
2811}
2812
2813/*
2814 * Tear down mapping from pktcdvd device to CD-ROM device.
2815 */
2816static int pkt_remove_dev(dev_t pkt_dev)
2817{
2818	struct pktcdvd_device *pd;
2819	int idx;
2820	int ret = 0;
2821
2822	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2823
2824	for (idx = 0; idx < MAX_WRITERS; idx++) {
2825		pd = pkt_devs[idx];
2826		if (pd && (pd->pkt_dev == pkt_dev))
2827			break;
2828	}
2829	if (idx == MAX_WRITERS) {
2830		pr_debug("dev not setup\n");
2831		ret = -ENXIO;
2832		goto out;
2833	}
2834
2835	if (pd->refcnt > 0) {
2836		ret = -EBUSY;
2837		goto out;
2838	}
2839	if (!IS_ERR(pd->cdrw.thread))
2840		kthread_stop(pd->cdrw.thread);
2841
2842	pkt_devs[idx] = NULL;
2843
2844	pkt_debugfs_dev_remove(pd);
2845	pkt_sysfs_dev_remove(pd);
2846
2847	blkdev_put(pd->bdev, FMODE_READ | FMODE_NDELAY);
2848
2849	remove_proc_entry(pd->name, pkt_proc);
2850	pkt_dbg(1, pd, "writer unmapped\n");
2851
2852	del_gendisk(pd->disk);
2853	blk_cleanup_queue(pd->disk->queue);
2854	put_disk(pd->disk);
2855
2856	mempool_destroy(pd->rb_pool);
2857	kfree(pd);
2858
2859	/* This is safe: open() is still holding a reference. */
2860	module_put(THIS_MODULE);
2861
2862out:
2863	mutex_unlock(&ctl_mutex);
2864	return ret;
2865}
2866
2867static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
2868{
2869	struct pktcdvd_device *pd;
2870
2871	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2872
2873	pd = pkt_find_dev_from_minor(ctrl_cmd->dev_index);
2874	if (pd) {
2875		ctrl_cmd->dev = new_encode_dev(pd->bdev->bd_dev);
2876		ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
2877	} else {
2878		ctrl_cmd->dev = 0;
2879		ctrl_cmd->pkt_dev = 0;
2880	}
2881	ctrl_cmd->num_devices = MAX_WRITERS;
2882
2883	mutex_unlock(&ctl_mutex);
2884}
2885
2886static long pkt_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2887{
2888	void __user *argp = (void __user *)arg;
2889	struct pkt_ctrl_command ctrl_cmd;
2890	int ret = 0;
2891	dev_t pkt_dev = 0;
2892
2893	if (cmd != PACKET_CTRL_CMD)
2894		return -ENOTTY;
2895
2896	if (copy_from_user(&ctrl_cmd, argp, sizeof(struct pkt_ctrl_command)))
2897		return -EFAULT;
2898
2899	switch (ctrl_cmd.command) {
2900	case PKT_CTRL_CMD_SETUP:
2901		if (!capable(CAP_SYS_ADMIN))
2902			return -EPERM;
2903		ret = pkt_setup_dev(new_decode_dev(ctrl_cmd.dev), &pkt_dev);
2904		ctrl_cmd.pkt_dev = new_encode_dev(pkt_dev);
2905		break;
2906	case PKT_CTRL_CMD_TEARDOWN:
2907		if (!capable(CAP_SYS_ADMIN))
2908			return -EPERM;
2909		ret = pkt_remove_dev(new_decode_dev(ctrl_cmd.pkt_dev));
2910		break;
2911	case PKT_CTRL_CMD_STATUS:
2912		pkt_get_status(&ctrl_cmd);
2913		break;
2914	default:
2915		return -ENOTTY;
2916	}
2917
2918	if (copy_to_user(argp, &ctrl_cmd, sizeof(struct pkt_ctrl_command)))
2919		return -EFAULT;
2920	return ret;
2921}
2922
2923#ifdef CONFIG_COMPAT
2924static long pkt_ctl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2925{
2926	return pkt_ctl_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
2927}
2928#endif
2929
2930static const struct file_operations pkt_ctl_fops = {
2931	.open		= nonseekable_open,
2932	.unlocked_ioctl	= pkt_ctl_ioctl,
2933#ifdef CONFIG_COMPAT
2934	.compat_ioctl	= pkt_ctl_compat_ioctl,
2935#endif
2936	.owner		= THIS_MODULE,
2937	.llseek		= no_llseek,
2938};
2939
2940static struct miscdevice pkt_misc = {
2941	.minor 		= MISC_DYNAMIC_MINOR,
2942	.name  		= DRIVER_NAME,
2943	.nodename	= "pktcdvd/control",
2944	.fops  		= &pkt_ctl_fops
2945};
2946
2947static int __init pkt_init(void)
2948{
2949	int ret;
2950
2951	mutex_init(&ctl_mutex);
2952
2953	psd_pool = mempool_create_kmalloc_pool(PSD_POOL_SIZE,
2954					sizeof(struct packet_stacked_data));
2955	if (!psd_pool)
2956		return -ENOMEM;
2957
2958	ret = register_blkdev(pktdev_major, DRIVER_NAME);
2959	if (ret < 0) {
2960		pr_err("unable to register block device\n");
2961		goto out2;
2962	}
2963	if (!pktdev_major)
2964		pktdev_major = ret;
2965
2966	ret = pkt_sysfs_init();
2967	if (ret)
2968		goto out;
2969
2970	pkt_debugfs_init();
2971
2972	ret = misc_register(&pkt_misc);
2973	if (ret) {
2974		pr_err("unable to register misc device\n");
2975		goto out_misc;
2976	}
2977
2978	pkt_proc = proc_mkdir("driver/"DRIVER_NAME, NULL);
2979
2980	return 0;
2981
2982out_misc:
2983	pkt_debugfs_cleanup();
2984	pkt_sysfs_cleanup();
2985out:
2986	unregister_blkdev(pktdev_major, DRIVER_NAME);
2987out2:
2988	mempool_destroy(psd_pool);
2989	return ret;
2990}
2991
2992static void __exit pkt_exit(void)
2993{
2994	remove_proc_entry("driver/"DRIVER_NAME, NULL);
2995	misc_deregister(&pkt_misc);
2996
2997	pkt_debugfs_cleanup();
2998	pkt_sysfs_cleanup();
2999
3000	unregister_blkdev(pktdev_major, DRIVER_NAME);
3001	mempool_destroy(psd_pool);
3002}
3003
3004MODULE_DESCRIPTION("Packet writing layer for CD/DVD drives");
3005MODULE_AUTHOR("Jens Axboe <axboe@suse.de>");
3006MODULE_LICENSE("GPL");
3007
3008module_init(pkt_init);
3009module_exit(pkt_exit);
3010