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 ->submit_bio 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#include <linux/nospec.h>
71#include <linux/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;
101static struct bio_set pkt_bio_set;
102
103static struct class	*class_pktcdvd = NULL;    /* /sys/class/pktcdvd */
104static struct dentry	*pkt_debugfs_root = NULL; /* /sys/kernel/debug/pktcdvd */
105
106/* forward declaration */
107static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev);
108static int pkt_remove_dev(dev_t pkt_dev);
109static int pkt_seq_show(struct seq_file *m, void *p);
110
111static sector_t get_zone(sector_t sector, struct pktcdvd_device *pd)
112{
113	return (sector + pd->offset) & ~(sector_t)(pd->settings.size - 1);
114}
115
116/*
117 * create and register a pktcdvd kernel object.
118 */
119static struct pktcdvd_kobj* pkt_kobj_create(struct pktcdvd_device *pd,
120					const char* name,
121					struct kobject* parent,
122					struct kobj_type* ktype)
123{
124	struct pktcdvd_kobj *p;
125	int error;
126
127	p = kzalloc(sizeof(*p), GFP_KERNEL);
128	if (!p)
129		return NULL;
130	p->pd = pd;
131	error = kobject_init_and_add(&p->kobj, ktype, parent, "%s", name);
132	if (error) {
133		kobject_put(&p->kobj);
134		return NULL;
135	}
136	kobject_uevent(&p->kobj, KOBJ_ADD);
137	return p;
138}
139/*
140 * remove a pktcdvd kernel object.
141 */
142static void pkt_kobj_remove(struct pktcdvd_kobj *p)
143{
144	if (p)
145		kobject_put(&p->kobj);
146}
147/*
148 * default release function for pktcdvd kernel objects.
149 */
150static void pkt_kobj_release(struct kobject *kobj)
151{
152	kfree(to_pktcdvdkobj(kobj));
153}
154
155
156/**********************************************************
157 *
158 * sysfs interface for pktcdvd
159 * by (C) 2006  Thomas Maier <balagi@justmail.de>
160 *
161 **********************************************************/
162
163#define DEF_ATTR(_obj,_name,_mode) \
164	static struct attribute _obj = { .name = _name, .mode = _mode }
165
166/**********************************************************
167  /sys/class/pktcdvd/pktcdvd[0-7]/
168                     stat/reset
169                     stat/packets_started
170                     stat/packets_finished
171                     stat/kb_written
172                     stat/kb_read
173                     stat/kb_read_gather
174                     write_queue/size
175                     write_queue/congestion_off
176                     write_queue/congestion_on
177 **********************************************************/
178
179DEF_ATTR(kobj_pkt_attr_st1, "reset", 0200);
180DEF_ATTR(kobj_pkt_attr_st2, "packets_started", 0444);
181DEF_ATTR(kobj_pkt_attr_st3, "packets_finished", 0444);
182DEF_ATTR(kobj_pkt_attr_st4, "kb_written", 0444);
183DEF_ATTR(kobj_pkt_attr_st5, "kb_read", 0444);
184DEF_ATTR(kobj_pkt_attr_st6, "kb_read_gather", 0444);
185
186static struct attribute *kobj_pkt_attrs_stat[] = {
187	&kobj_pkt_attr_st1,
188	&kobj_pkt_attr_st2,
189	&kobj_pkt_attr_st3,
190	&kobj_pkt_attr_st4,
191	&kobj_pkt_attr_st5,
192	&kobj_pkt_attr_st6,
193	NULL
194};
195
196DEF_ATTR(kobj_pkt_attr_wq1, "size", 0444);
197DEF_ATTR(kobj_pkt_attr_wq2, "congestion_off", 0644);
198DEF_ATTR(kobj_pkt_attr_wq3, "congestion_on",  0644);
199
200static struct attribute *kobj_pkt_attrs_wqueue[] = {
201	&kobj_pkt_attr_wq1,
202	&kobj_pkt_attr_wq2,
203	&kobj_pkt_attr_wq3,
204	NULL
205};
206
207static ssize_t kobj_pkt_show(struct kobject *kobj,
208			struct attribute *attr, char *data)
209{
210	struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
211	int n = 0;
212	int v;
213	if (strcmp(attr->name, "packets_started") == 0) {
214		n = sprintf(data, "%lu\n", pd->stats.pkt_started);
215
216	} else if (strcmp(attr->name, "packets_finished") == 0) {
217		n = sprintf(data, "%lu\n", pd->stats.pkt_ended);
218
219	} else if (strcmp(attr->name, "kb_written") == 0) {
220		n = sprintf(data, "%lu\n", pd->stats.secs_w >> 1);
221
222	} else if (strcmp(attr->name, "kb_read") == 0) {
223		n = sprintf(data, "%lu\n", pd->stats.secs_r >> 1);
224
225	} else if (strcmp(attr->name, "kb_read_gather") == 0) {
226		n = sprintf(data, "%lu\n", pd->stats.secs_rg >> 1);
227
228	} else if (strcmp(attr->name, "size") == 0) {
229		spin_lock(&pd->lock);
230		v = pd->bio_queue_size;
231		spin_unlock(&pd->lock);
232		n = sprintf(data, "%d\n", v);
233
234	} else if (strcmp(attr->name, "congestion_off") == 0) {
235		spin_lock(&pd->lock);
236		v = pd->write_congestion_off;
237		spin_unlock(&pd->lock);
238		n = sprintf(data, "%d\n", v);
239
240	} else if (strcmp(attr->name, "congestion_on") == 0) {
241		spin_lock(&pd->lock);
242		v = pd->write_congestion_on;
243		spin_unlock(&pd->lock);
244		n = sprintf(data, "%d\n", v);
245	}
246	return n;
247}
248
249static void init_write_congestion_marks(int* lo, int* hi)
250{
251	if (*hi > 0) {
252		*hi = max(*hi, 500);
253		*hi = min(*hi, 1000000);
254		if (*lo <= 0)
255			*lo = *hi - 100;
256		else {
257			*lo = min(*lo, *hi - 100);
258			*lo = max(*lo, 100);
259		}
260	} else {
261		*hi = -1;
262		*lo = -1;
263	}
264}
265
266static ssize_t kobj_pkt_store(struct kobject *kobj,
267			struct attribute *attr,
268			const char *data, size_t len)
269{
270	struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
271	int val;
272
273	if (strcmp(attr->name, "reset") == 0 && len > 0) {
274		pd->stats.pkt_started = 0;
275		pd->stats.pkt_ended = 0;
276		pd->stats.secs_w = 0;
277		pd->stats.secs_rg = 0;
278		pd->stats.secs_r = 0;
279
280	} else if (strcmp(attr->name, "congestion_off") == 0
281		   && sscanf(data, "%d", &val) == 1) {
282		spin_lock(&pd->lock);
283		pd->write_congestion_off = val;
284		init_write_congestion_marks(&pd->write_congestion_off,
285					&pd->write_congestion_on);
286		spin_unlock(&pd->lock);
287
288	} else if (strcmp(attr->name, "congestion_on") == 0
289		   && sscanf(data, "%d", &val) == 1) {
290		spin_lock(&pd->lock);
291		pd->write_congestion_on = val;
292		init_write_congestion_marks(&pd->write_congestion_off,
293					&pd->write_congestion_on);
294		spin_unlock(&pd->lock);
295	}
296	return len;
297}
298
299static const struct sysfs_ops kobj_pkt_ops = {
300	.show = kobj_pkt_show,
301	.store = kobj_pkt_store
302};
303static struct kobj_type kobj_pkt_type_stat = {
304	.release = pkt_kobj_release,
305	.sysfs_ops = &kobj_pkt_ops,
306	.default_attrs = kobj_pkt_attrs_stat
307};
308static struct kobj_type kobj_pkt_type_wqueue = {
309	.release = pkt_kobj_release,
310	.sysfs_ops = &kobj_pkt_ops,
311	.default_attrs = kobj_pkt_attrs_wqueue
312};
313
314static void pkt_sysfs_dev_new(struct pktcdvd_device *pd)
315{
316	if (class_pktcdvd) {
317		pd->dev = device_create(class_pktcdvd, NULL, MKDEV(0, 0), NULL,
318					"%s", pd->name);
319		if (IS_ERR(pd->dev))
320			pd->dev = NULL;
321	}
322	if (pd->dev) {
323		pd->kobj_stat = pkt_kobj_create(pd, "stat",
324					&pd->dev->kobj,
325					&kobj_pkt_type_stat);
326		pd->kobj_wqueue = pkt_kobj_create(pd, "write_queue",
327					&pd->dev->kobj,
328					&kobj_pkt_type_wqueue);
329	}
330}
331
332static void pkt_sysfs_dev_remove(struct pktcdvd_device *pd)
333{
334	pkt_kobj_remove(pd->kobj_stat);
335	pkt_kobj_remove(pd->kobj_wqueue);
336	if (class_pktcdvd)
337		device_unregister(pd->dev);
338}
339
340
341/********************************************************************
342  /sys/class/pktcdvd/
343                     add            map block device
344                     remove         unmap packet dev
345                     device_map     show mappings
346 *******************************************************************/
347
348static void class_pktcdvd_release(struct class *cls)
349{
350	kfree(cls);
351}
352
353static ssize_t device_map_show(struct class *c, struct class_attribute *attr,
354			       char *data)
355{
356	int n = 0;
357	int idx;
358	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
359	for (idx = 0; idx < MAX_WRITERS; idx++) {
360		struct pktcdvd_device *pd = pkt_devs[idx];
361		if (!pd)
362			continue;
363		n += sprintf(data+n, "%s %u:%u %u:%u\n",
364			pd->name,
365			MAJOR(pd->pkt_dev), MINOR(pd->pkt_dev),
366			MAJOR(pd->bdev->bd_dev),
367			MINOR(pd->bdev->bd_dev));
368	}
369	mutex_unlock(&ctl_mutex);
370	return n;
371}
372static CLASS_ATTR_RO(device_map);
373
374static ssize_t add_store(struct class *c, struct class_attribute *attr,
375			 const char *buf, 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}
393static CLASS_ATTR_WO(add);
394
395static ssize_t remove_store(struct class *c, struct class_attribute *attr,
396			    const char *buf, size_t count)
397{
398	unsigned int major, minor;
399	if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
400		pkt_remove_dev(MKDEV(major, minor));
401		return count;
402	}
403	return -EINVAL;
404}
405static CLASS_ATTR_WO(remove);
406
407static struct attribute *class_pktcdvd_attrs[] = {
408	&class_attr_add.attr,
409	&class_attr_remove.attr,
410	&class_attr_device_map.attr,
411	NULL,
412};
413ATTRIBUTE_GROUPS(class_pktcdvd);
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_groups = class_pktcdvd_groups;
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", 0444,
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			     REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
708	if (IS_ERR(rq))
709		return PTR_ERR(rq);
710
711	if (cgc->buflen) {
712		ret = blk_rq_map_kern(q, rq, cgc->buffer, cgc->buflen,
713				      GFP_NOIO);
714		if (ret)
715			goto out;
716	}
717
718	scsi_req(rq)->cmd_len = COMMAND_SIZE(cgc->cmd[0]);
719	memcpy(scsi_req(rq)->cmd, cgc->cmd, CDROM_PACKET_SIZE);
720
721	rq->timeout = 60*HZ;
722	if (cgc->quiet)
723		rq->rq_flags |= RQF_QUIET;
724
725	blk_execute_rq(rq->q, pd->bdev->bd_disk, rq, 0);
726	if (scsi_req(rq)->result)
727		ret = -EIO;
728out:
729	blk_put_request(rq);
730	return ret;
731}
732
733static const char *sense_key_string(__u8 index)
734{
735	static const char * const info[] = {
736		"No sense", "Recovered error", "Not ready",
737		"Medium error", "Hardware error", "Illegal request",
738		"Unit attention", "Data protect", "Blank check",
739	};
740
741	return index < ARRAY_SIZE(info) ? info[index] : "INVALID";
742}
743
744/*
745 * A generic sense dump / resolve mechanism should be implemented across
746 * all ATAPI + SCSI devices.
747 */
748static void pkt_dump_sense(struct pktcdvd_device *pd,
749			   struct packet_command *cgc)
750{
751	struct scsi_sense_hdr *sshdr = cgc->sshdr;
752
753	if (sshdr)
754		pkt_err(pd, "%*ph - sense %02x.%02x.%02x (%s)\n",
755			CDROM_PACKET_SIZE, cgc->cmd,
756			sshdr->sense_key, sshdr->asc, sshdr->ascq,
757			sense_key_string(sshdr->sense_key));
758	else
759		pkt_err(pd, "%*ph - no sense\n", CDROM_PACKET_SIZE, cgc->cmd);
760}
761
762/*
763 * flush the drive cache to media
764 */
765static int pkt_flush_cache(struct pktcdvd_device *pd)
766{
767	struct packet_command cgc;
768
769	init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
770	cgc.cmd[0] = GPCMD_FLUSH_CACHE;
771	cgc.quiet = 1;
772
773	/*
774	 * the IMMED bit -- we default to not setting it, although that
775	 * would allow a much faster close, this is safer
776	 */
777#if 0
778	cgc.cmd[1] = 1 << 1;
779#endif
780	return pkt_generic_packet(pd, &cgc);
781}
782
783/*
784 * speed is given as the normal factor, e.g. 4 for 4x
785 */
786static noinline_for_stack int pkt_set_speed(struct pktcdvd_device *pd,
787				unsigned write_speed, unsigned read_speed)
788{
789	struct packet_command cgc;
790	struct scsi_sense_hdr sshdr;
791	int ret;
792
793	init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
794	cgc.sshdr = &sshdr;
795	cgc.cmd[0] = GPCMD_SET_SPEED;
796	cgc.cmd[2] = (read_speed >> 8) & 0xff;
797	cgc.cmd[3] = read_speed & 0xff;
798	cgc.cmd[4] = (write_speed >> 8) & 0xff;
799	cgc.cmd[5] = write_speed & 0xff;
800
801	ret = pkt_generic_packet(pd, &cgc);
802	if (ret)
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		submit_bio_noacct(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
947static void pkt_end_io_read(struct bio *bio)
948{
949	struct packet_data *pkt = bio->bi_private;
950	struct pktcdvd_device *pd = pkt->pd;
951	BUG_ON(!pd);
952
953	pkt_dbg(2, pd, "bio=%p sec0=%llx sec=%llx err=%d\n",
954		bio, (unsigned long long)pkt->sector,
955		(unsigned long long)bio->bi_iter.bi_sector, bio->bi_status);
956
957	if (bio->bi_status)
958		atomic_inc(&pkt->io_errors);
959	if (atomic_dec_and_test(&pkt->io_wait)) {
960		atomic_inc(&pkt->run_sm);
961		wake_up(&pd->wqueue);
962	}
963	pkt_bio_finished(pd);
964}
965
966static void pkt_end_io_packet_write(struct bio *bio)
967{
968	struct packet_data *pkt = bio->bi_private;
969	struct pktcdvd_device *pd = pkt->pd;
970	BUG_ON(!pd);
971
972	pkt_dbg(2, pd, "id=%d, err=%d\n", pkt->id, bio->bi_status);
973
974	pd->stats.pkt_ended++;
975
976	pkt_bio_finished(pd);
977	atomic_dec(&pkt->io_wait);
978	atomic_inc(&pkt->run_sm);
979	wake_up(&pd->wqueue);
980}
981
982/*
983 * Schedule reads for the holes in a packet
984 */
985static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt)
986{
987	int frames_read = 0;
988	struct bio *bio;
989	int f;
990	char written[PACKET_MAX_SIZE];
991
992	BUG_ON(bio_list_empty(&pkt->orig_bios));
993
994	atomic_set(&pkt->io_wait, 0);
995	atomic_set(&pkt->io_errors, 0);
996
997	/*
998	 * Figure out which frames we need to read before we can write.
999	 */
1000	memset(written, 0, sizeof(written));
1001	spin_lock(&pkt->lock);
1002	bio_list_for_each(bio, &pkt->orig_bios) {
1003		int first_frame = (bio->bi_iter.bi_sector - pkt->sector) /
1004			(CD_FRAMESIZE >> 9);
1005		int num_frames = bio->bi_iter.bi_size / CD_FRAMESIZE;
1006		pd->stats.secs_w += num_frames * (CD_FRAMESIZE >> 9);
1007		BUG_ON(first_frame < 0);
1008		BUG_ON(first_frame + num_frames > pkt->frames);
1009		for (f = first_frame; f < first_frame + num_frames; f++)
1010			written[f] = 1;
1011	}
1012	spin_unlock(&pkt->lock);
1013
1014	if (pkt->cache_valid) {
1015		pkt_dbg(2, pd, "zone %llx cached\n",
1016			(unsigned long long)pkt->sector);
1017		goto out_account;
1018	}
1019
1020	/*
1021	 * Schedule reads for missing parts of the packet.
1022	 */
1023	for (f = 0; f < pkt->frames; f++) {
1024		int p, offset;
1025
1026		if (written[f])
1027			continue;
1028
1029		bio = pkt->r_bios[f];
1030		bio_reset(bio);
1031		bio->bi_iter.bi_sector = pkt->sector + f * (CD_FRAMESIZE >> 9);
1032		bio_set_dev(bio, pd->bdev);
1033		bio->bi_end_io = pkt_end_io_read;
1034		bio->bi_private = pkt;
1035
1036		p = (f * CD_FRAMESIZE) / PAGE_SIZE;
1037		offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1038		pkt_dbg(2, pd, "Adding frame %d, page:%p offs:%d\n",
1039			f, pkt->pages[p], offset);
1040		if (!bio_add_page(bio, pkt->pages[p], CD_FRAMESIZE, offset))
1041			BUG();
1042
1043		atomic_inc(&pkt->io_wait);
1044		bio_set_op_attrs(bio, REQ_OP_READ, 0);
1045		pkt_queue_bio(pd, bio);
1046		frames_read++;
1047	}
1048
1049out_account:
1050	pkt_dbg(2, pd, "need %d frames for zone %llx\n",
1051		frames_read, (unsigned long long)pkt->sector);
1052	pd->stats.pkt_started++;
1053	pd->stats.secs_rg += frames_read * (CD_FRAMESIZE >> 9);
1054}
1055
1056/*
1057 * Find a packet matching zone, or the least recently used packet if
1058 * there is no match.
1059 */
1060static struct packet_data *pkt_get_packet_data(struct pktcdvd_device *pd, int zone)
1061{
1062	struct packet_data *pkt;
1063
1064	list_for_each_entry(pkt, &pd->cdrw.pkt_free_list, list) {
1065		if (pkt->sector == zone || pkt->list.next == &pd->cdrw.pkt_free_list) {
1066			list_del_init(&pkt->list);
1067			if (pkt->sector != zone)
1068				pkt->cache_valid = 0;
1069			return pkt;
1070		}
1071	}
1072	BUG();
1073	return NULL;
1074}
1075
1076static void pkt_put_packet_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1077{
1078	if (pkt->cache_valid) {
1079		list_add(&pkt->list, &pd->cdrw.pkt_free_list);
1080	} else {
1081		list_add_tail(&pkt->list, &pd->cdrw.pkt_free_list);
1082	}
1083}
1084
1085static inline void pkt_set_state(struct packet_data *pkt, enum packet_data_state state)
1086{
1087#if PACKET_DEBUG > 1
1088	static const char *state_name[] = {
1089		"IDLE", "WAITING", "READ_WAIT", "WRITE_WAIT", "RECOVERY", "FINISHED"
1090	};
1091	enum packet_data_state old_state = pkt->state;
1092	pkt_dbg(2, pd, "pkt %2d : s=%6llx %s -> %s\n",
1093		pkt->id, (unsigned long long)pkt->sector,
1094		state_name[old_state], state_name[state]);
1095#endif
1096	pkt->state = state;
1097}
1098
1099/*
1100 * Scan the work queue to see if we can start a new packet.
1101 * returns non-zero if any work was done.
1102 */
1103static int pkt_handle_queue(struct pktcdvd_device *pd)
1104{
1105	struct packet_data *pkt, *p;
1106	struct bio *bio = NULL;
1107	sector_t zone = 0; /* Suppress gcc warning */
1108	struct pkt_rb_node *node, *first_node;
1109	struct rb_node *n;
1110	int wakeup;
1111
1112	atomic_set(&pd->scan_queue, 0);
1113
1114	if (list_empty(&pd->cdrw.pkt_free_list)) {
1115		pkt_dbg(2, pd, "no pkt\n");
1116		return 0;
1117	}
1118
1119	/*
1120	 * Try to find a zone we are not already working on.
1121	 */
1122	spin_lock(&pd->lock);
1123	first_node = pkt_rbtree_find(pd, pd->current_sector);
1124	if (!first_node) {
1125		n = rb_first(&pd->bio_queue);
1126		if (n)
1127			first_node = rb_entry(n, struct pkt_rb_node, rb_node);
1128	}
1129	node = first_node;
1130	while (node) {
1131		bio = node->bio;
1132		zone = get_zone(bio->bi_iter.bi_sector, pd);
1133		list_for_each_entry(p, &pd->cdrw.pkt_active_list, list) {
1134			if (p->sector == zone) {
1135				bio = NULL;
1136				goto try_next_bio;
1137			}
1138		}
1139		break;
1140try_next_bio:
1141		node = pkt_rbtree_next(node);
1142		if (!node) {
1143			n = rb_first(&pd->bio_queue);
1144			if (n)
1145				node = rb_entry(n, struct pkt_rb_node, rb_node);
1146		}
1147		if (node == first_node)
1148			node = NULL;
1149	}
1150	spin_unlock(&pd->lock);
1151	if (!bio) {
1152		pkt_dbg(2, pd, "no bio\n");
1153		return 0;
1154	}
1155
1156	pkt = pkt_get_packet_data(pd, zone);
1157
1158	pd->current_sector = zone + pd->settings.size;
1159	pkt->sector = zone;
1160	BUG_ON(pkt->frames != pd->settings.size >> 2);
1161	pkt->write_size = 0;
1162
1163	/*
1164	 * Scan work queue for bios in the same zone and link them
1165	 * to this packet.
1166	 */
1167	spin_lock(&pd->lock);
1168	pkt_dbg(2, pd, "looking for zone %llx\n", (unsigned long long)zone);
1169	while ((node = pkt_rbtree_find(pd, zone)) != NULL) {
1170		bio = node->bio;
1171		pkt_dbg(2, pd, "found zone=%llx\n", (unsigned long long)
1172			get_zone(bio->bi_iter.bi_sector, pd));
1173		if (get_zone(bio->bi_iter.bi_sector, pd) != zone)
1174			break;
1175		pkt_rbtree_erase(pd, node);
1176		spin_lock(&pkt->lock);
1177		bio_list_add(&pkt->orig_bios, bio);
1178		pkt->write_size += bio->bi_iter.bi_size / CD_FRAMESIZE;
1179		spin_unlock(&pkt->lock);
1180	}
1181	/* check write congestion marks, and if bio_queue_size is
1182	   below, wake up any waiters */
1183	wakeup = (pd->write_congestion_on > 0
1184	 		&& pd->bio_queue_size <= pd->write_congestion_off);
1185	spin_unlock(&pd->lock);
1186	if (wakeup) {
1187		clear_bdi_congested(pd->disk->queue->backing_dev_info,
1188					BLK_RW_ASYNC);
1189	}
1190
1191	pkt->sleep_time = max(PACKET_WAIT_TIME, 1);
1192	pkt_set_state(pkt, PACKET_WAITING_STATE);
1193	atomic_set(&pkt->run_sm, 1);
1194
1195	spin_lock(&pd->cdrw.active_list_lock);
1196	list_add(&pkt->list, &pd->cdrw.pkt_active_list);
1197	spin_unlock(&pd->cdrw.active_list_lock);
1198
1199	return 1;
1200}
1201
1202/*
1203 * Assemble a bio to write one packet and queue the bio for processing
1204 * by the underlying block device.
1205 */
1206static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
1207{
1208	int f;
1209
1210	bio_reset(pkt->w_bio);
1211	pkt->w_bio->bi_iter.bi_sector = pkt->sector;
1212	bio_set_dev(pkt->w_bio, pd->bdev);
1213	pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
1214	pkt->w_bio->bi_private = pkt;
1215
1216	/* XXX: locking? */
1217	for (f = 0; f < pkt->frames; f++) {
1218		struct page *page = pkt->pages[(f * CD_FRAMESIZE) / PAGE_SIZE];
1219		unsigned offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1220
1221		if (!bio_add_page(pkt->w_bio, page, CD_FRAMESIZE, offset))
1222			BUG();
1223	}
1224	pkt_dbg(2, pd, "vcnt=%d\n", pkt->w_bio->bi_vcnt);
1225
1226	/*
1227	 * Fill-in bvec with data from orig_bios.
1228	 */
1229	spin_lock(&pkt->lock);
1230	bio_list_copy_data(pkt->w_bio, pkt->orig_bios.head);
1231
1232	pkt_set_state(pkt, PACKET_WRITE_WAIT_STATE);
1233	spin_unlock(&pkt->lock);
1234
1235	pkt_dbg(2, pd, "Writing %d frames for zone %llx\n",
1236		pkt->write_size, (unsigned long long)pkt->sector);
1237
1238	if (test_bit(PACKET_MERGE_SEGS, &pd->flags) || (pkt->write_size < pkt->frames))
1239		pkt->cache_valid = 1;
1240	else
1241		pkt->cache_valid = 0;
1242
1243	/* Start the write request */
1244	atomic_set(&pkt->io_wait, 1);
1245	bio_set_op_attrs(pkt->w_bio, REQ_OP_WRITE, 0);
1246	pkt_queue_bio(pd, pkt->w_bio);
1247}
1248
1249static void pkt_finish_packet(struct packet_data *pkt, blk_status_t status)
1250{
1251	struct bio *bio;
1252
1253	if (status)
1254		pkt->cache_valid = 0;
1255
1256	/* Finish all bios corresponding to this packet */
1257	while ((bio = bio_list_pop(&pkt->orig_bios))) {
1258		bio->bi_status = status;
1259		bio_endio(bio);
1260	}
1261}
1262
1263static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data *pkt)
1264{
1265	pkt_dbg(2, pd, "pkt %d\n", pkt->id);
1266
1267	for (;;) {
1268		switch (pkt->state) {
1269		case PACKET_WAITING_STATE:
1270			if ((pkt->write_size < pkt->frames) && (pkt->sleep_time > 0))
1271				return;
1272
1273			pkt->sleep_time = 0;
1274			pkt_gather_data(pd, pkt);
1275			pkt_set_state(pkt, PACKET_READ_WAIT_STATE);
1276			break;
1277
1278		case PACKET_READ_WAIT_STATE:
1279			if (atomic_read(&pkt->io_wait) > 0)
1280				return;
1281
1282			if (atomic_read(&pkt->io_errors) > 0) {
1283				pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1284			} else {
1285				pkt_start_write(pd, pkt);
1286			}
1287			break;
1288
1289		case PACKET_WRITE_WAIT_STATE:
1290			if (atomic_read(&pkt->io_wait) > 0)
1291				return;
1292
1293			if (!pkt->w_bio->bi_status) {
1294				pkt_set_state(pkt, PACKET_FINISHED_STATE);
1295			} else {
1296				pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1297			}
1298			break;
1299
1300		case PACKET_RECOVERY_STATE:
1301			pkt_dbg(2, pd, "No recovery possible\n");
1302			pkt_set_state(pkt, PACKET_FINISHED_STATE);
1303			break;
1304
1305		case PACKET_FINISHED_STATE:
1306			pkt_finish_packet(pkt, pkt->w_bio->bi_status);
1307			return;
1308
1309		default:
1310			BUG();
1311			break;
1312		}
1313	}
1314}
1315
1316static void pkt_handle_packets(struct pktcdvd_device *pd)
1317{
1318	struct packet_data *pkt, *next;
1319
1320	/*
1321	 * Run state machine for active packets
1322	 */
1323	list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1324		if (atomic_read(&pkt->run_sm) > 0) {
1325			atomic_set(&pkt->run_sm, 0);
1326			pkt_run_state_machine(pd, pkt);
1327		}
1328	}
1329
1330	/*
1331	 * Move no longer active packets to the free list
1332	 */
1333	spin_lock(&pd->cdrw.active_list_lock);
1334	list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_active_list, list) {
1335		if (pkt->state == PACKET_FINISHED_STATE) {
1336			list_del(&pkt->list);
1337			pkt_put_packet_data(pd, pkt);
1338			pkt_set_state(pkt, PACKET_IDLE_STATE);
1339			atomic_set(&pd->scan_queue, 1);
1340		}
1341	}
1342	spin_unlock(&pd->cdrw.active_list_lock);
1343}
1344
1345static void pkt_count_states(struct pktcdvd_device *pd, int *states)
1346{
1347	struct packet_data *pkt;
1348	int i;
1349
1350	for (i = 0; i < PACKET_NUM_STATES; i++)
1351		states[i] = 0;
1352
1353	spin_lock(&pd->cdrw.active_list_lock);
1354	list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1355		states[pkt->state]++;
1356	}
1357	spin_unlock(&pd->cdrw.active_list_lock);
1358}
1359
1360/*
1361 * kcdrwd is woken up when writes have been queued for one of our
1362 * registered devices
1363 */
1364static int kcdrwd(void *foobar)
1365{
1366	struct pktcdvd_device *pd = foobar;
1367	struct packet_data *pkt;
1368	long min_sleep_time, residue;
1369
1370	set_user_nice(current, MIN_NICE);
1371	set_freezable();
1372
1373	for (;;) {
1374		DECLARE_WAITQUEUE(wait, current);
1375
1376		/*
1377		 * Wait until there is something to do
1378		 */
1379		add_wait_queue(&pd->wqueue, &wait);
1380		for (;;) {
1381			set_current_state(TASK_INTERRUPTIBLE);
1382
1383			/* Check if we need to run pkt_handle_queue */
1384			if (atomic_read(&pd->scan_queue) > 0)
1385				goto work_to_do;
1386
1387			/* Check if we need to run the state machine for some packet */
1388			list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1389				if (atomic_read(&pkt->run_sm) > 0)
1390					goto work_to_do;
1391			}
1392
1393			/* Check if we need to process the iosched queues */
1394			if (atomic_read(&pd->iosched.attention) != 0)
1395				goto work_to_do;
1396
1397			/* Otherwise, go to sleep */
1398			if (PACKET_DEBUG > 1) {
1399				int states[PACKET_NUM_STATES];
1400				pkt_count_states(pd, states);
1401				pkt_dbg(2, pd, "i:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
1402					states[0], states[1], states[2],
1403					states[3], states[4], states[5]);
1404			}
1405
1406			min_sleep_time = MAX_SCHEDULE_TIMEOUT;
1407			list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1408				if (pkt->sleep_time && pkt->sleep_time < min_sleep_time)
1409					min_sleep_time = pkt->sleep_time;
1410			}
1411
1412			pkt_dbg(2, pd, "sleeping\n");
1413			residue = schedule_timeout(min_sleep_time);
1414			pkt_dbg(2, pd, "wake up\n");
1415
1416			/* make swsusp happy with our thread */
1417			try_to_freeze();
1418
1419			list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1420				if (!pkt->sleep_time)
1421					continue;
1422				pkt->sleep_time -= min_sleep_time - residue;
1423				if (pkt->sleep_time <= 0) {
1424					pkt->sleep_time = 0;
1425					atomic_inc(&pkt->run_sm);
1426				}
1427			}
1428
1429			if (kthread_should_stop())
1430				break;
1431		}
1432work_to_do:
1433		set_current_state(TASK_RUNNING);
1434		remove_wait_queue(&pd->wqueue, &wait);
1435
1436		if (kthread_should_stop())
1437			break;
1438
1439		/*
1440		 * if pkt_handle_queue returns true, we can queue
1441		 * another request.
1442		 */
1443		while (pkt_handle_queue(pd))
1444			;
1445
1446		/*
1447		 * Handle packet state machine
1448		 */
1449		pkt_handle_packets(pd);
1450
1451		/*
1452		 * Handle iosched queues
1453		 */
1454		pkt_iosched_process_queue(pd);
1455	}
1456
1457	return 0;
1458}
1459
1460static void pkt_print_settings(struct pktcdvd_device *pd)
1461{
1462	pkt_info(pd, "%s packets, %u blocks, Mode-%c disc\n",
1463		 pd->settings.fp ? "Fixed" : "Variable",
1464		 pd->settings.size >> 2,
1465		 pd->settings.block_mode == 8 ? '1' : '2');
1466}
1467
1468static int pkt_mode_sense(struct pktcdvd_device *pd, struct packet_command *cgc, int page_code, int page_control)
1469{
1470	memset(cgc->cmd, 0, sizeof(cgc->cmd));
1471
1472	cgc->cmd[0] = GPCMD_MODE_SENSE_10;
1473	cgc->cmd[2] = page_code | (page_control << 6);
1474	cgc->cmd[7] = cgc->buflen >> 8;
1475	cgc->cmd[8] = cgc->buflen & 0xff;
1476	cgc->data_direction = CGC_DATA_READ;
1477	return pkt_generic_packet(pd, cgc);
1478}
1479
1480static int pkt_mode_select(struct pktcdvd_device *pd, struct packet_command *cgc)
1481{
1482	memset(cgc->cmd, 0, sizeof(cgc->cmd));
1483	memset(cgc->buffer, 0, 2);
1484	cgc->cmd[0] = GPCMD_MODE_SELECT_10;
1485	cgc->cmd[1] = 0x10;		/* PF */
1486	cgc->cmd[7] = cgc->buflen >> 8;
1487	cgc->cmd[8] = cgc->buflen & 0xff;
1488	cgc->data_direction = CGC_DATA_WRITE;
1489	return pkt_generic_packet(pd, cgc);
1490}
1491
1492static int pkt_get_disc_info(struct pktcdvd_device *pd, disc_information *di)
1493{
1494	struct packet_command cgc;
1495	int ret;
1496
1497	/* set up command and get the disc info */
1498	init_cdrom_command(&cgc, di, sizeof(*di), CGC_DATA_READ);
1499	cgc.cmd[0] = GPCMD_READ_DISC_INFO;
1500	cgc.cmd[8] = cgc.buflen = 2;
1501	cgc.quiet = 1;
1502
1503	ret = pkt_generic_packet(pd, &cgc);
1504	if (ret)
1505		return ret;
1506
1507	/* not all drives have the same disc_info length, so requeue
1508	 * packet with the length the drive tells us it can supply
1509	 */
1510	cgc.buflen = be16_to_cpu(di->disc_information_length) +
1511		     sizeof(di->disc_information_length);
1512
1513	if (cgc.buflen > sizeof(disc_information))
1514		cgc.buflen = sizeof(disc_information);
1515
1516	cgc.cmd[8] = cgc.buflen;
1517	return pkt_generic_packet(pd, &cgc);
1518}
1519
1520static int pkt_get_track_info(struct pktcdvd_device *pd, __u16 track, __u8 type, track_information *ti)
1521{
1522	struct packet_command cgc;
1523	int ret;
1524
1525	init_cdrom_command(&cgc, ti, 8, CGC_DATA_READ);
1526	cgc.cmd[0] = GPCMD_READ_TRACK_RZONE_INFO;
1527	cgc.cmd[1] = type & 3;
1528	cgc.cmd[4] = (track & 0xff00) >> 8;
1529	cgc.cmd[5] = track & 0xff;
1530	cgc.cmd[8] = 8;
1531	cgc.quiet = 1;
1532
1533	ret = pkt_generic_packet(pd, &cgc);
1534	if (ret)
1535		return ret;
1536
1537	cgc.buflen = be16_to_cpu(ti->track_information_length) +
1538		     sizeof(ti->track_information_length);
1539
1540	if (cgc.buflen > sizeof(track_information))
1541		cgc.buflen = sizeof(track_information);
1542
1543	cgc.cmd[8] = cgc.buflen;
1544	return pkt_generic_packet(pd, &cgc);
1545}
1546
1547static noinline_for_stack int pkt_get_last_written(struct pktcdvd_device *pd,
1548						long *last_written)
1549{
1550	disc_information di;
1551	track_information ti;
1552	__u32 last_track;
1553	int ret;
1554
1555	ret = pkt_get_disc_info(pd, &di);
1556	if (ret)
1557		return ret;
1558
1559	last_track = (di.last_track_msb << 8) | di.last_track_lsb;
1560	ret = pkt_get_track_info(pd, last_track, 1, &ti);
1561	if (ret)
1562		return ret;
1563
1564	/* if this track is blank, try the previous. */
1565	if (ti.blank) {
1566		last_track--;
1567		ret = pkt_get_track_info(pd, last_track, 1, &ti);
1568		if (ret)
1569			return ret;
1570	}
1571
1572	/* if last recorded field is valid, return it. */
1573	if (ti.lra_v) {
1574		*last_written = be32_to_cpu(ti.last_rec_address);
1575	} else {
1576		/* make it up instead */
1577		*last_written = be32_to_cpu(ti.track_start) +
1578				be32_to_cpu(ti.track_size);
1579		if (ti.free_blocks)
1580			*last_written -= (be32_to_cpu(ti.free_blocks) + 7);
1581	}
1582	return 0;
1583}
1584
1585/*
1586 * write mode select package based on pd->settings
1587 */
1588static noinline_for_stack int pkt_set_write_settings(struct pktcdvd_device *pd)
1589{
1590	struct packet_command cgc;
1591	struct scsi_sense_hdr sshdr;
1592	write_param_page *wp;
1593	char buffer[128];
1594	int ret, size;
1595
1596	/* doesn't apply to DVD+RW or DVD-RAM */
1597	if ((pd->mmc3_profile == 0x1a) || (pd->mmc3_profile == 0x12))
1598		return 0;
1599
1600	memset(buffer, 0, sizeof(buffer));
1601	init_cdrom_command(&cgc, buffer, sizeof(*wp), CGC_DATA_READ);
1602	cgc.sshdr = &sshdr;
1603	ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0);
1604	if (ret) {
1605		pkt_dump_sense(pd, &cgc);
1606		return ret;
1607	}
1608
1609	size = 2 + ((buffer[0] << 8) | (buffer[1] & 0xff));
1610	pd->mode_offset = (buffer[6] << 8) | (buffer[7] & 0xff);
1611	if (size > sizeof(buffer))
1612		size = sizeof(buffer);
1613
1614	/*
1615	 * now get it all
1616	 */
1617	init_cdrom_command(&cgc, buffer, size, CGC_DATA_READ);
1618	cgc.sshdr = &sshdr;
1619	ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0);
1620	if (ret) {
1621		pkt_dump_sense(pd, &cgc);
1622		return ret;
1623	}
1624
1625	/*
1626	 * write page is offset header + block descriptor length
1627	 */
1628	wp = (write_param_page *) &buffer[sizeof(struct mode_page_header) + pd->mode_offset];
1629
1630	wp->fp = pd->settings.fp;
1631	wp->track_mode = pd->settings.track_mode;
1632	wp->write_type = pd->settings.write_type;
1633	wp->data_block_type = pd->settings.block_mode;
1634
1635	wp->multi_session = 0;
1636
1637#ifdef PACKET_USE_LS
1638	wp->link_size = 7;
1639	wp->ls_v = 1;
1640#endif
1641
1642	if (wp->data_block_type == PACKET_BLOCK_MODE1) {
1643		wp->session_format = 0;
1644		wp->subhdr2 = 0x20;
1645	} else if (wp->data_block_type == PACKET_BLOCK_MODE2) {
1646		wp->session_format = 0x20;
1647		wp->subhdr2 = 8;
1648#if 0
1649		wp->mcn[0] = 0x80;
1650		memcpy(&wp->mcn[1], PACKET_MCN, sizeof(wp->mcn) - 1);
1651#endif
1652	} else {
1653		/*
1654		 * paranoia
1655		 */
1656		pkt_err(pd, "write mode wrong %d\n", wp->data_block_type);
1657		return 1;
1658	}
1659	wp->packet_size = cpu_to_be32(pd->settings.size >> 2);
1660
1661	cgc.buflen = cgc.cmd[8] = size;
1662	ret = pkt_mode_select(pd, &cgc);
1663	if (ret) {
1664		pkt_dump_sense(pd, &cgc);
1665		return ret;
1666	}
1667
1668	pkt_print_settings(pd);
1669	return 0;
1670}
1671
1672/*
1673 * 1 -- we can write to this track, 0 -- we can't
1674 */
1675static int pkt_writable_track(struct pktcdvd_device *pd, track_information *ti)
1676{
1677	switch (pd->mmc3_profile) {
1678		case 0x1a: /* DVD+RW */
1679		case 0x12: /* DVD-RAM */
1680			/* The track is always writable on DVD+RW/DVD-RAM */
1681			return 1;
1682		default:
1683			break;
1684	}
1685
1686	if (!ti->packet || !ti->fp)
1687		return 0;
1688
1689	/*
1690	 * "good" settings as per Mt Fuji.
1691	 */
1692	if (ti->rt == 0 && ti->blank == 0)
1693		return 1;
1694
1695	if (ti->rt == 0 && ti->blank == 1)
1696		return 1;
1697
1698	if (ti->rt == 1 && ti->blank == 0)
1699		return 1;
1700
1701	pkt_err(pd, "bad state %d-%d-%d\n", ti->rt, ti->blank, ti->packet);
1702	return 0;
1703}
1704
1705/*
1706 * 1 -- we can write to this disc, 0 -- we can't
1707 */
1708static int pkt_writable_disc(struct pktcdvd_device *pd, disc_information *di)
1709{
1710	switch (pd->mmc3_profile) {
1711		case 0x0a: /* CD-RW */
1712		case 0xffff: /* MMC3 not supported */
1713			break;
1714		case 0x1a: /* DVD+RW */
1715		case 0x13: /* DVD-RW */
1716		case 0x12: /* DVD-RAM */
1717			return 1;
1718		default:
1719			pkt_dbg(2, pd, "Wrong disc profile (%x)\n",
1720				pd->mmc3_profile);
1721			return 0;
1722	}
1723
1724	/*
1725	 * for disc type 0xff we should probably reserve a new track.
1726	 * but i'm not sure, should we leave this to user apps? probably.
1727	 */
1728	if (di->disc_type == 0xff) {
1729		pkt_notice(pd, "unknown disc - no track?\n");
1730		return 0;
1731	}
1732
1733	if (di->disc_type != 0x20 && di->disc_type != 0) {
1734		pkt_err(pd, "wrong disc type (%x)\n", di->disc_type);
1735		return 0;
1736	}
1737
1738	if (di->erasable == 0) {
1739		pkt_notice(pd, "disc not erasable\n");
1740		return 0;
1741	}
1742
1743	if (di->border_status == PACKET_SESSION_RESERVED) {
1744		pkt_err(pd, "can't write to last track (reserved)\n");
1745		return 0;
1746	}
1747
1748	return 1;
1749}
1750
1751static noinline_for_stack int pkt_probe_settings(struct pktcdvd_device *pd)
1752{
1753	struct packet_command cgc;
1754	unsigned char buf[12];
1755	disc_information di;
1756	track_information ti;
1757	int ret, track;
1758
1759	init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1760	cgc.cmd[0] = GPCMD_GET_CONFIGURATION;
1761	cgc.cmd[8] = 8;
1762	ret = pkt_generic_packet(pd, &cgc);
1763	pd->mmc3_profile = ret ? 0xffff : buf[6] << 8 | buf[7];
1764
1765	memset(&di, 0, sizeof(disc_information));
1766	memset(&ti, 0, sizeof(track_information));
1767
1768	ret = pkt_get_disc_info(pd, &di);
1769	if (ret) {
1770		pkt_err(pd, "failed get_disc\n");
1771		return ret;
1772	}
1773
1774	if (!pkt_writable_disc(pd, &di))
1775		return -EROFS;
1776
1777	pd->type = di.erasable ? PACKET_CDRW : PACKET_CDR;
1778
1779	track = 1; /* (di.last_track_msb << 8) | di.last_track_lsb; */
1780	ret = pkt_get_track_info(pd, track, 1, &ti);
1781	if (ret) {
1782		pkt_err(pd, "failed get_track\n");
1783		return ret;
1784	}
1785
1786	if (!pkt_writable_track(pd, &ti)) {
1787		pkt_err(pd, "can't write to this track\n");
1788		return -EROFS;
1789	}
1790
1791	/*
1792	 * we keep packet size in 512 byte units, makes it easier to
1793	 * deal with request calculations.
1794	 */
1795	pd->settings.size = be32_to_cpu(ti.fixed_packet_size) << 2;
1796	if (pd->settings.size == 0) {
1797		pkt_notice(pd, "detected zero packet size!\n");
1798		return -ENXIO;
1799	}
1800	if (pd->settings.size > PACKET_MAX_SECTORS) {
1801		pkt_err(pd, "packet size is too big\n");
1802		return -EROFS;
1803	}
1804	pd->settings.fp = ti.fp;
1805	pd->offset = (be32_to_cpu(ti.track_start) << 2) & (pd->settings.size - 1);
1806
1807	if (ti.nwa_v) {
1808		pd->nwa = be32_to_cpu(ti.next_writable);
1809		set_bit(PACKET_NWA_VALID, &pd->flags);
1810	}
1811
1812	/*
1813	 * in theory we could use lra on -RW media as well and just zero
1814	 * blocks that haven't been written yet, but in practice that
1815	 * is just a no-go. we'll use that for -R, naturally.
1816	 */
1817	if (ti.lra_v) {
1818		pd->lra = be32_to_cpu(ti.last_rec_address);
1819		set_bit(PACKET_LRA_VALID, &pd->flags);
1820	} else {
1821		pd->lra = 0xffffffff;
1822		set_bit(PACKET_LRA_VALID, &pd->flags);
1823	}
1824
1825	/*
1826	 * fine for now
1827	 */
1828	pd->settings.link_loss = 7;
1829	pd->settings.write_type = 0;	/* packet */
1830	pd->settings.track_mode = ti.track_mode;
1831
1832	/*
1833	 * mode1 or mode2 disc
1834	 */
1835	switch (ti.data_mode) {
1836		case PACKET_MODE1:
1837			pd->settings.block_mode = PACKET_BLOCK_MODE1;
1838			break;
1839		case PACKET_MODE2:
1840			pd->settings.block_mode = PACKET_BLOCK_MODE2;
1841			break;
1842		default:
1843			pkt_err(pd, "unknown data mode\n");
1844			return -EROFS;
1845	}
1846	return 0;
1847}
1848
1849/*
1850 * enable/disable write caching on drive
1851 */
1852static noinline_for_stack int pkt_write_caching(struct pktcdvd_device *pd,
1853						int set)
1854{
1855	struct packet_command cgc;
1856	struct scsi_sense_hdr sshdr;
1857	unsigned char buf[64];
1858	int ret;
1859
1860	init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1861	cgc.sshdr = &sshdr;
1862	cgc.buflen = pd->mode_offset + 12;
1863
1864	/*
1865	 * caching mode page might not be there, so quiet this command
1866	 */
1867	cgc.quiet = 1;
1868
1869	ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0);
1870	if (ret)
1871		return ret;
1872
1873	buf[pd->mode_offset + 10] |= (!!set << 2);
1874
1875	cgc.buflen = cgc.cmd[8] = 2 + ((buf[0] << 8) | (buf[1] & 0xff));
1876	ret = pkt_mode_select(pd, &cgc);
1877	if (ret) {
1878		pkt_err(pd, "write caching control failed\n");
1879		pkt_dump_sense(pd, &cgc);
1880	} else if (!ret && set)
1881		pkt_notice(pd, "enabled write caching\n");
1882	return ret;
1883}
1884
1885static int pkt_lock_door(struct pktcdvd_device *pd, int lockflag)
1886{
1887	struct packet_command cgc;
1888
1889	init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
1890	cgc.cmd[0] = GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL;
1891	cgc.cmd[4] = lockflag ? 1 : 0;
1892	return pkt_generic_packet(pd, &cgc);
1893}
1894
1895/*
1896 * Returns drive maximum write speed
1897 */
1898static noinline_for_stack int pkt_get_max_speed(struct pktcdvd_device *pd,
1899						unsigned *write_speed)
1900{
1901	struct packet_command cgc;
1902	struct scsi_sense_hdr sshdr;
1903	unsigned char buf[256+18];
1904	unsigned char *cap_buf;
1905	int ret, offset;
1906
1907	cap_buf = &buf[sizeof(struct mode_page_header) + pd->mode_offset];
1908	init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_UNKNOWN);
1909	cgc.sshdr = &sshdr;
1910
1911	ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1912	if (ret) {
1913		cgc.buflen = pd->mode_offset + cap_buf[1] + 2 +
1914			     sizeof(struct mode_page_header);
1915		ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1916		if (ret) {
1917			pkt_dump_sense(pd, &cgc);
1918			return ret;
1919		}
1920	}
1921
1922	offset = 20;			    /* Obsoleted field, used by older drives */
1923	if (cap_buf[1] >= 28)
1924		offset = 28;		    /* Current write speed selected */
1925	if (cap_buf[1] >= 30) {
1926		/* If the drive reports at least one "Logical Unit Write
1927		 * Speed Performance Descriptor Block", use the information
1928		 * in the first block. (contains the highest speed)
1929		 */
1930		int num_spdb = (cap_buf[30] << 8) + cap_buf[31];
1931		if (num_spdb > 0)
1932			offset = 34;
1933	}
1934
1935	*write_speed = (cap_buf[offset] << 8) | cap_buf[offset + 1];
1936	return 0;
1937}
1938
1939/* These tables from cdrecord - I don't have orange book */
1940/* standard speed CD-RW (1-4x) */
1941static char clv_to_speed[16] = {
1942	/* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
1943	   0, 2, 4, 6, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
1944};
1945/* high speed CD-RW (-10x) */
1946static char hs_clv_to_speed[16] = {
1947	/* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
1948	   0, 2, 4, 6, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
1949};
1950/* ultra high speed CD-RW */
1951static char us_clv_to_speed[16] = {
1952	/* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
1953	   0, 2, 4, 8, 0, 0,16, 0,24,32,40,48, 0, 0, 0, 0
1954};
1955
1956/*
1957 * reads the maximum media speed from ATIP
1958 */
1959static noinline_for_stack int pkt_media_speed(struct pktcdvd_device *pd,
1960						unsigned *speed)
1961{
1962	struct packet_command cgc;
1963	struct scsi_sense_hdr sshdr;
1964	unsigned char buf[64];
1965	unsigned int size, st, sp;
1966	int ret;
1967
1968	init_cdrom_command(&cgc, buf, 2, CGC_DATA_READ);
1969	cgc.sshdr = &sshdr;
1970	cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
1971	cgc.cmd[1] = 2;
1972	cgc.cmd[2] = 4; /* READ ATIP */
1973	cgc.cmd[8] = 2;
1974	ret = pkt_generic_packet(pd, &cgc);
1975	if (ret) {
1976		pkt_dump_sense(pd, &cgc);
1977		return ret;
1978	}
1979	size = ((unsigned int) buf[0]<<8) + buf[1] + 2;
1980	if (size > sizeof(buf))
1981		size = sizeof(buf);
1982
1983	init_cdrom_command(&cgc, buf, size, CGC_DATA_READ);
1984	cgc.sshdr = &sshdr;
1985	cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
1986	cgc.cmd[1] = 2;
1987	cgc.cmd[2] = 4;
1988	cgc.cmd[8] = size;
1989	ret = pkt_generic_packet(pd, &cgc);
1990	if (ret) {
1991		pkt_dump_sense(pd, &cgc);
1992		return ret;
1993	}
1994
1995	if (!(buf[6] & 0x40)) {
1996		pkt_notice(pd, "disc type is not CD-RW\n");
1997		return 1;
1998	}
1999	if (!(buf[6] & 0x4)) {
2000		pkt_notice(pd, "A1 values on media are not valid, maybe not CDRW?\n");
2001		return 1;
2002	}
2003
2004	st = (buf[6] >> 3) & 0x7; /* disc sub-type */
2005
2006	sp = buf[16] & 0xf; /* max speed from ATIP A1 field */
2007
2008	/* Info from cdrecord */
2009	switch (st) {
2010		case 0: /* standard speed */
2011			*speed = clv_to_speed[sp];
2012			break;
2013		case 1: /* high speed */
2014			*speed = hs_clv_to_speed[sp];
2015			break;
2016		case 2: /* ultra high speed */
2017			*speed = us_clv_to_speed[sp];
2018			break;
2019		default:
2020			pkt_notice(pd, "unknown disc sub-type %d\n", st);
2021			return 1;
2022	}
2023	if (*speed) {
2024		pkt_info(pd, "maximum media speed: %d\n", *speed);
2025		return 0;
2026	} else {
2027		pkt_notice(pd, "unknown speed %d for sub-type %d\n", sp, st);
2028		return 1;
2029	}
2030}
2031
2032static noinline_for_stack int pkt_perform_opc(struct pktcdvd_device *pd)
2033{
2034	struct packet_command cgc;
2035	struct scsi_sense_hdr sshdr;
2036	int ret;
2037
2038	pkt_dbg(2, pd, "Performing OPC\n");
2039
2040	init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2041	cgc.sshdr = &sshdr;
2042	cgc.timeout = 60*HZ;
2043	cgc.cmd[0] = GPCMD_SEND_OPC;
2044	cgc.cmd[1] = 1;
2045	ret = pkt_generic_packet(pd, &cgc);
2046	if (ret)
2047		pkt_dump_sense(pd, &cgc);
2048	return ret;
2049}
2050
2051static int pkt_open_write(struct pktcdvd_device *pd)
2052{
2053	int ret;
2054	unsigned int write_speed, media_write_speed, read_speed;
2055
2056	ret = pkt_probe_settings(pd);
2057	if (ret) {
2058		pkt_dbg(2, pd, "failed probe\n");
2059		return ret;
2060	}
2061
2062	ret = pkt_set_write_settings(pd);
2063	if (ret) {
2064		pkt_dbg(1, pd, "failed saving write settings\n");
2065		return -EIO;
2066	}
2067
2068	pkt_write_caching(pd, USE_WCACHING);
2069
2070	ret = pkt_get_max_speed(pd, &write_speed);
2071	if (ret)
2072		write_speed = 16 * 177;
2073	switch (pd->mmc3_profile) {
2074		case 0x13: /* DVD-RW */
2075		case 0x1a: /* DVD+RW */
2076		case 0x12: /* DVD-RAM */
2077			pkt_dbg(1, pd, "write speed %ukB/s\n", write_speed);
2078			break;
2079		default:
2080			ret = pkt_media_speed(pd, &media_write_speed);
2081			if (ret)
2082				media_write_speed = 16;
2083			write_speed = min(write_speed, media_write_speed * 177);
2084			pkt_dbg(1, pd, "write speed %ux\n", write_speed / 176);
2085			break;
2086	}
2087	read_speed = write_speed;
2088
2089	ret = pkt_set_speed(pd, write_speed, read_speed);
2090	if (ret) {
2091		pkt_dbg(1, pd, "couldn't set write speed\n");
2092		return -EIO;
2093	}
2094	pd->write_speed = write_speed;
2095	pd->read_speed = read_speed;
2096
2097	ret = pkt_perform_opc(pd);
2098	if (ret) {
2099		pkt_dbg(1, pd, "Optimum Power Calibration failed\n");
2100	}
2101
2102	return 0;
2103}
2104
2105/*
2106 * called at open time.
2107 */
2108static int pkt_open_dev(struct pktcdvd_device *pd, fmode_t write)
2109{
2110	int ret;
2111	long lba;
2112	struct request_queue *q;
2113	struct block_device *bdev;
2114
2115	/*
2116	 * We need to re-open the cdrom device without O_NONBLOCK to be able
2117	 * to read/write from/to it. It is already opened in O_NONBLOCK mode
2118	 * so open should not fail.
2119	 */
2120	bdev = blkdev_get_by_dev(pd->bdev->bd_dev, FMODE_READ | FMODE_EXCL, pd);
2121	if (IS_ERR(bdev)) {
2122		ret = PTR_ERR(bdev);
2123		goto out;
2124	}
2125
2126	ret = pkt_get_last_written(pd, &lba);
2127	if (ret) {
2128		pkt_err(pd, "pkt_get_last_written failed\n");
2129		goto out_putdev;
2130	}
2131
2132	set_capacity(pd->disk, lba << 2);
2133	set_capacity(pd->bdev->bd_disk, lba << 2);
2134	bd_set_nr_sectors(pd->bdev, lba << 2);
2135
2136	q = bdev_get_queue(pd->bdev);
2137	if (write) {
2138		ret = pkt_open_write(pd);
2139		if (ret)
2140			goto out_putdev;
2141		/*
2142		 * Some CDRW drives can not handle writes larger than one packet,
2143		 * even if the size is a multiple of the packet size.
2144		 */
2145		blk_queue_max_hw_sectors(q, pd->settings.size);
2146		set_bit(PACKET_WRITABLE, &pd->flags);
2147	} else {
2148		pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2149		clear_bit(PACKET_WRITABLE, &pd->flags);
2150	}
2151
2152	ret = pkt_set_segment_merging(pd, q);
2153	if (ret)
2154		goto out_putdev;
2155
2156	if (write) {
2157		if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
2158			pkt_err(pd, "not enough memory for buffers\n");
2159			ret = -ENOMEM;
2160			goto out_putdev;
2161		}
2162		pkt_info(pd, "%lukB available on disc\n", lba << 1);
2163	}
2164
2165	return 0;
2166
2167out_putdev:
2168	blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
2169out:
2170	return ret;
2171}
2172
2173/*
2174 * called when the device is closed. makes sure that the device flushes
2175 * the internal cache before we close.
2176 */
2177static void pkt_release_dev(struct pktcdvd_device *pd, int flush)
2178{
2179	if (flush && pkt_flush_cache(pd))
2180		pkt_dbg(1, pd, "not flushing cache\n");
2181
2182	pkt_lock_door(pd, 0);
2183
2184	pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2185	blkdev_put(pd->bdev, FMODE_READ | FMODE_EXCL);
2186
2187	pkt_shrink_pktlist(pd);
2188}
2189
2190static struct pktcdvd_device *pkt_find_dev_from_minor(unsigned int dev_minor)
2191{
2192	if (dev_minor >= MAX_WRITERS)
2193		return NULL;
2194
2195	dev_minor = array_index_nospec(dev_minor, MAX_WRITERS);
2196	return pkt_devs[dev_minor];
2197}
2198
2199static int pkt_open(struct block_device *bdev, fmode_t mode)
2200{
2201	struct pktcdvd_device *pd = NULL;
2202	int ret;
2203
2204	mutex_lock(&pktcdvd_mutex);
2205	mutex_lock(&ctl_mutex);
2206	pd = pkt_find_dev_from_minor(MINOR(bdev->bd_dev));
2207	if (!pd) {
2208		ret = -ENODEV;
2209		goto out;
2210	}
2211	BUG_ON(pd->refcnt < 0);
2212
2213	pd->refcnt++;
2214	if (pd->refcnt > 1) {
2215		if ((mode & FMODE_WRITE) &&
2216		    !test_bit(PACKET_WRITABLE, &pd->flags)) {
2217			ret = -EBUSY;
2218			goto out_dec;
2219		}
2220	} else {
2221		ret = pkt_open_dev(pd, mode & FMODE_WRITE);
2222		if (ret)
2223			goto out_dec;
2224		/*
2225		 * needed here as well, since ext2 (among others) may change
2226		 * the blocksize at mount time
2227		 */
2228		set_blocksize(bdev, CD_FRAMESIZE);
2229	}
2230
2231	mutex_unlock(&ctl_mutex);
2232	mutex_unlock(&pktcdvd_mutex);
2233	return 0;
2234
2235out_dec:
2236	pd->refcnt--;
2237out:
2238	mutex_unlock(&ctl_mutex);
2239	mutex_unlock(&pktcdvd_mutex);
2240	return ret;
2241}
2242
2243static void pkt_close(struct gendisk *disk, fmode_t mode)
2244{
2245	struct pktcdvd_device *pd = disk->private_data;
2246
2247	mutex_lock(&pktcdvd_mutex);
2248	mutex_lock(&ctl_mutex);
2249	pd->refcnt--;
2250	BUG_ON(pd->refcnt < 0);
2251	if (pd->refcnt == 0) {
2252		int flush = test_bit(PACKET_WRITABLE, &pd->flags);
2253		pkt_release_dev(pd, flush);
2254	}
2255	mutex_unlock(&ctl_mutex);
2256	mutex_unlock(&pktcdvd_mutex);
2257}
2258
2259
2260static void pkt_end_io_read_cloned(struct bio *bio)
2261{
2262	struct packet_stacked_data *psd = bio->bi_private;
2263	struct pktcdvd_device *pd = psd->pd;
2264
2265	psd->bio->bi_status = bio->bi_status;
2266	bio_put(bio);
2267	bio_endio(psd->bio);
2268	mempool_free(psd, &psd_pool);
2269	pkt_bio_finished(pd);
2270}
2271
2272static void pkt_make_request_read(struct pktcdvd_device *pd, struct bio *bio)
2273{
2274	struct bio *cloned_bio = bio_clone_fast(bio, GFP_NOIO, &pkt_bio_set);
2275	struct packet_stacked_data *psd = mempool_alloc(&psd_pool, GFP_NOIO);
2276
2277	psd->pd = pd;
2278	psd->bio = bio;
2279	bio_set_dev(cloned_bio, pd->bdev);
2280	cloned_bio->bi_private = psd;
2281	cloned_bio->bi_end_io = pkt_end_io_read_cloned;
2282	pd->stats.secs_r += bio_sectors(bio);
2283	pkt_queue_bio(pd, cloned_bio);
2284}
2285
2286static void pkt_make_request_write(struct request_queue *q, struct bio *bio)
2287{
2288	struct pktcdvd_device *pd = q->queuedata;
2289	sector_t zone;
2290	struct packet_data *pkt;
2291	int was_empty, blocked_bio;
2292	struct pkt_rb_node *node;
2293
2294	zone = get_zone(bio->bi_iter.bi_sector, pd);
2295
2296	/*
2297	 * If we find a matching packet in state WAITING or READ_WAIT, we can
2298	 * just append this bio to that packet.
2299	 */
2300	spin_lock(&pd->cdrw.active_list_lock);
2301	blocked_bio = 0;
2302	list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
2303		if (pkt->sector == zone) {
2304			spin_lock(&pkt->lock);
2305			if ((pkt->state == PACKET_WAITING_STATE) ||
2306			    (pkt->state == PACKET_READ_WAIT_STATE)) {
2307				bio_list_add(&pkt->orig_bios, bio);
2308				pkt->write_size +=
2309					bio->bi_iter.bi_size / CD_FRAMESIZE;
2310				if ((pkt->write_size >= pkt->frames) &&
2311				    (pkt->state == PACKET_WAITING_STATE)) {
2312					atomic_inc(&pkt->run_sm);
2313					wake_up(&pd->wqueue);
2314				}
2315				spin_unlock(&pkt->lock);
2316				spin_unlock(&pd->cdrw.active_list_lock);
2317				return;
2318			} else {
2319				blocked_bio = 1;
2320			}
2321			spin_unlock(&pkt->lock);
2322		}
2323	}
2324	spin_unlock(&pd->cdrw.active_list_lock);
2325
2326 	/*
2327	 * Test if there is enough room left in the bio work queue
2328	 * (queue size >= congestion on mark).
2329	 * If not, wait till the work queue size is below the congestion off mark.
2330	 */
2331	spin_lock(&pd->lock);
2332	if (pd->write_congestion_on > 0
2333	    && pd->bio_queue_size >= pd->write_congestion_on) {
2334		set_bdi_congested(q->backing_dev_info, BLK_RW_ASYNC);
2335		do {
2336			spin_unlock(&pd->lock);
2337			congestion_wait(BLK_RW_ASYNC, HZ);
2338			spin_lock(&pd->lock);
2339		} while(pd->bio_queue_size > pd->write_congestion_off);
2340	}
2341	spin_unlock(&pd->lock);
2342
2343	/*
2344	 * No matching packet found. Store the bio in the work queue.
2345	 */
2346	node = mempool_alloc(&pd->rb_pool, GFP_NOIO);
2347	node->bio = bio;
2348	spin_lock(&pd->lock);
2349	BUG_ON(pd->bio_queue_size < 0);
2350	was_empty = (pd->bio_queue_size == 0);
2351	pkt_rbtree_insert(pd, node);
2352	spin_unlock(&pd->lock);
2353
2354	/*
2355	 * Wake up the worker thread.
2356	 */
2357	atomic_set(&pd->scan_queue, 1);
2358	if (was_empty) {
2359		/* This wake_up is required for correct operation */
2360		wake_up(&pd->wqueue);
2361	} else if (!list_empty(&pd->cdrw.pkt_free_list) && !blocked_bio) {
2362		/*
2363		 * This wake up is not required for correct operation,
2364		 * but improves performance in some cases.
2365		 */
2366		wake_up(&pd->wqueue);
2367	}
2368}
2369
2370static blk_qc_t pkt_submit_bio(struct bio *bio)
2371{
2372	struct pktcdvd_device *pd;
2373	char b[BDEVNAME_SIZE];
2374	struct bio *split;
2375
2376	blk_queue_split(&bio);
2377
2378	pd = bio->bi_disk->queue->queuedata;
2379	if (!pd) {
2380		pr_err("%s incorrect request queue\n", bio_devname(bio, b));
2381		goto end_io;
2382	}
2383
2384	pkt_dbg(2, pd, "start = %6llx stop = %6llx\n",
2385		(unsigned long long)bio->bi_iter.bi_sector,
2386		(unsigned long long)bio_end_sector(bio));
2387
2388	/*
2389	 * Clone READ bios so we can have our own bi_end_io callback.
2390	 */
2391	if (bio_data_dir(bio) == READ) {
2392		pkt_make_request_read(pd, bio);
2393		return BLK_QC_T_NONE;
2394	}
2395
2396	if (!test_bit(PACKET_WRITABLE, &pd->flags)) {
2397		pkt_notice(pd, "WRITE for ro device (%llu)\n",
2398			   (unsigned long long)bio->bi_iter.bi_sector);
2399		goto end_io;
2400	}
2401
2402	if (!bio->bi_iter.bi_size || (bio->bi_iter.bi_size % CD_FRAMESIZE)) {
2403		pkt_err(pd, "wrong bio size\n");
2404		goto end_io;
2405	}
2406
2407	do {
2408		sector_t zone = get_zone(bio->bi_iter.bi_sector, pd);
2409		sector_t last_zone = get_zone(bio_end_sector(bio) - 1, pd);
2410
2411		if (last_zone != zone) {
2412			BUG_ON(last_zone != zone + pd->settings.size);
2413
2414			split = bio_split(bio, last_zone -
2415					  bio->bi_iter.bi_sector,
2416					  GFP_NOIO, &pkt_bio_set);
2417			bio_chain(split, bio);
2418		} else {
2419			split = bio;
2420		}
2421
2422		pkt_make_request_write(bio->bi_disk->queue, split);
2423	} while (split != bio);
2424
2425	return BLK_QC_T_NONE;
2426end_io:
2427	bio_io_error(bio);
2428	return BLK_QC_T_NONE;
2429}
2430
2431static void pkt_init_queue(struct pktcdvd_device *pd)
2432{
2433	struct request_queue *q = pd->disk->queue;
2434
2435	blk_queue_logical_block_size(q, CD_FRAMESIZE);
2436	blk_queue_max_hw_sectors(q, PACKET_MAX_SECTORS);
2437	q->queuedata = pd;
2438}
2439
2440static int pkt_seq_show(struct seq_file *m, void *p)
2441{
2442	struct pktcdvd_device *pd = m->private;
2443	char *msg;
2444	char bdev_buf[BDEVNAME_SIZE];
2445	int states[PACKET_NUM_STATES];
2446
2447	seq_printf(m, "Writer %s mapped to %s:\n", pd->name,
2448		   bdevname(pd->bdev, bdev_buf));
2449
2450	seq_printf(m, "\nSettings:\n");
2451	seq_printf(m, "\tpacket size:\t\t%dkB\n", pd->settings.size / 2);
2452
2453	if (pd->settings.write_type == 0)
2454		msg = "Packet";
2455	else
2456		msg = "Unknown";
2457	seq_printf(m, "\twrite type:\t\t%s\n", msg);
2458
2459	seq_printf(m, "\tpacket type:\t\t%s\n", pd->settings.fp ? "Fixed" : "Variable");
2460	seq_printf(m, "\tlink loss:\t\t%d\n", pd->settings.link_loss);
2461
2462	seq_printf(m, "\ttrack mode:\t\t%d\n", pd->settings.track_mode);
2463
2464	if (pd->settings.block_mode == PACKET_BLOCK_MODE1)
2465		msg = "Mode 1";
2466	else if (pd->settings.block_mode == PACKET_BLOCK_MODE2)
2467		msg = "Mode 2";
2468	else
2469		msg = "Unknown";
2470	seq_printf(m, "\tblock mode:\t\t%s\n", msg);
2471
2472	seq_printf(m, "\nStatistics:\n");
2473	seq_printf(m, "\tpackets started:\t%lu\n", pd->stats.pkt_started);
2474	seq_printf(m, "\tpackets ended:\t\t%lu\n", pd->stats.pkt_ended);
2475	seq_printf(m, "\twritten:\t\t%lukB\n", pd->stats.secs_w >> 1);
2476	seq_printf(m, "\tread gather:\t\t%lukB\n", pd->stats.secs_rg >> 1);
2477	seq_printf(m, "\tread:\t\t\t%lukB\n", pd->stats.secs_r >> 1);
2478
2479	seq_printf(m, "\nMisc:\n");
2480	seq_printf(m, "\treference count:\t%d\n", pd->refcnt);
2481	seq_printf(m, "\tflags:\t\t\t0x%lx\n", pd->flags);
2482	seq_printf(m, "\tread speed:\t\t%ukB/s\n", pd->read_speed);
2483	seq_printf(m, "\twrite speed:\t\t%ukB/s\n", pd->write_speed);
2484	seq_printf(m, "\tstart offset:\t\t%lu\n", pd->offset);
2485	seq_printf(m, "\tmode page offset:\t%u\n", pd->mode_offset);
2486
2487	seq_printf(m, "\nQueue state:\n");
2488	seq_printf(m, "\tbios queued:\t\t%d\n", pd->bio_queue_size);
2489	seq_printf(m, "\tbios pending:\t\t%d\n", atomic_read(&pd->cdrw.pending_bios));
2490	seq_printf(m, "\tcurrent sector:\t\t0x%llx\n", (unsigned long long)pd->current_sector);
2491
2492	pkt_count_states(pd, states);
2493	seq_printf(m, "\tstate:\t\t\ti:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
2494		   states[0], states[1], states[2], states[3], states[4], states[5]);
2495
2496	seq_printf(m, "\twrite congestion marks:\toff=%d on=%d\n",
2497			pd->write_congestion_off,
2498			pd->write_congestion_on);
2499	return 0;
2500}
2501
2502static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
2503{
2504	int i;
2505	char b[BDEVNAME_SIZE];
2506	struct block_device *bdev;
2507
2508	if (pd->pkt_dev == dev) {
2509		pkt_err(pd, "recursive setup not allowed\n");
2510		return -EBUSY;
2511	}
2512	for (i = 0; i < MAX_WRITERS; i++) {
2513		struct pktcdvd_device *pd2 = pkt_devs[i];
2514		if (!pd2)
2515			continue;
2516		if (pd2->bdev->bd_dev == dev) {
2517			pkt_err(pd, "%s already setup\n",
2518				bdevname(pd2->bdev, b));
2519			return -EBUSY;
2520		}
2521		if (pd2->pkt_dev == dev) {
2522			pkt_err(pd, "can't chain pktcdvd devices\n");
2523			return -EBUSY;
2524		}
2525	}
2526
2527	bdev = blkdev_get_by_dev(dev, FMODE_READ | FMODE_NDELAY, NULL);
2528	if (IS_ERR(bdev))
2529		return PTR_ERR(bdev);
2530	if (!blk_queue_scsi_passthrough(bdev_get_queue(bdev))) {
2531		blkdev_put(bdev, FMODE_READ | FMODE_NDELAY);
2532		return -EINVAL;
2533	}
2534
2535	/* This is safe, since we have a reference from open(). */
2536	__module_get(THIS_MODULE);
2537
2538	pd->bdev = bdev;
2539	set_blocksize(bdev, CD_FRAMESIZE);
2540
2541	pkt_init_queue(pd);
2542
2543	atomic_set(&pd->cdrw.pending_bios, 0);
2544	pd->cdrw.thread = kthread_run(kcdrwd, pd, "%s", pd->name);
2545	if (IS_ERR(pd->cdrw.thread)) {
2546		pkt_err(pd, "can't start kernel thread\n");
2547		goto out_mem;
2548	}
2549
2550	proc_create_single_data(pd->name, 0, pkt_proc, pkt_seq_show, pd);
2551	pkt_dbg(1, pd, "writer mapped to %s\n", bdevname(bdev, b));
2552	return 0;
2553
2554out_mem:
2555	blkdev_put(bdev, FMODE_READ | FMODE_NDELAY);
2556	/* This is safe: open() is still holding a reference. */
2557	module_put(THIS_MODULE);
2558	return -ENOMEM;
2559}
2560
2561static int pkt_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg)
2562{
2563	struct pktcdvd_device *pd = bdev->bd_disk->private_data;
2564	int ret;
2565
2566	pkt_dbg(2, pd, "cmd %x, dev %d:%d\n",
2567		cmd, MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev));
2568
2569	mutex_lock(&pktcdvd_mutex);
2570	switch (cmd) {
2571	case CDROMEJECT:
2572		/*
2573		 * The door gets locked when the device is opened, so we
2574		 * have to unlock it or else the eject command fails.
2575		 */
2576		if (pd->refcnt == 1)
2577			pkt_lock_door(pd, 0);
2578		fallthrough;
2579	/*
2580	 * forward selected CDROM ioctls to CD-ROM, for UDF
2581	 */
2582	case CDROMMULTISESSION:
2583	case CDROMREADTOCENTRY:
2584	case CDROM_LAST_WRITTEN:
2585	case CDROM_SEND_PACKET:
2586	case SCSI_IOCTL_SEND_COMMAND:
2587		ret = __blkdev_driver_ioctl(pd->bdev, mode, cmd, arg);
2588		break;
2589
2590	default:
2591		pkt_dbg(2, pd, "Unknown ioctl (%x)\n", cmd);
2592		ret = -ENOTTY;
2593	}
2594	mutex_unlock(&pktcdvd_mutex);
2595
2596	return ret;
2597}
2598
2599static unsigned int pkt_check_events(struct gendisk *disk,
2600				     unsigned int clearing)
2601{
2602	struct pktcdvd_device *pd = disk->private_data;
2603	struct gendisk *attached_disk;
2604
2605	if (!pd)
2606		return 0;
2607	if (!pd->bdev)
2608		return 0;
2609	attached_disk = pd->bdev->bd_disk;
2610	if (!attached_disk || !attached_disk->fops->check_events)
2611		return 0;
2612	return attached_disk->fops->check_events(attached_disk, clearing);
2613}
2614
2615static char *pkt_devnode(struct gendisk *disk, umode_t *mode)
2616{
2617	return kasprintf(GFP_KERNEL, "pktcdvd/%s", disk->disk_name);
2618}
2619
2620static const struct block_device_operations pktcdvd_ops = {
2621	.owner =		THIS_MODULE,
2622	.submit_bio =		pkt_submit_bio,
2623	.open =			pkt_open,
2624	.release =		pkt_close,
2625	.ioctl =		pkt_ioctl,
2626	.compat_ioctl =		blkdev_compat_ptr_ioctl,
2627	.check_events =		pkt_check_events,
2628	.devnode =		pkt_devnode,
2629};
2630
2631/*
2632 * Set up mapping from pktcdvd device to CD-ROM device.
2633 */
2634static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
2635{
2636	int idx;
2637	int ret = -ENOMEM;
2638	struct pktcdvd_device *pd;
2639	struct gendisk *disk;
2640
2641	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2642
2643	for (idx = 0; idx < MAX_WRITERS; idx++)
2644		if (!pkt_devs[idx])
2645			break;
2646	if (idx == MAX_WRITERS) {
2647		pr_err("max %d writers supported\n", MAX_WRITERS);
2648		ret = -EBUSY;
2649		goto out_mutex;
2650	}
2651
2652	pd = kzalloc(sizeof(struct pktcdvd_device), GFP_KERNEL);
2653	if (!pd)
2654		goto out_mutex;
2655
2656	ret = mempool_init_kmalloc_pool(&pd->rb_pool, PKT_RB_POOL_SIZE,
2657					sizeof(struct pkt_rb_node));
2658	if (ret)
2659		goto out_mem;
2660
2661	INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
2662	INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
2663	spin_lock_init(&pd->cdrw.active_list_lock);
2664
2665	spin_lock_init(&pd->lock);
2666	spin_lock_init(&pd->iosched.lock);
2667	bio_list_init(&pd->iosched.read_queue);
2668	bio_list_init(&pd->iosched.write_queue);
2669	sprintf(pd->name, DRIVER_NAME"%d", idx);
2670	init_waitqueue_head(&pd->wqueue);
2671	pd->bio_queue = RB_ROOT;
2672
2673	pd->write_congestion_on  = write_congestion_on;
2674	pd->write_congestion_off = write_congestion_off;
2675
2676	ret = -ENOMEM;
2677	disk = alloc_disk(1);
2678	if (!disk)
2679		goto out_mem;
2680	pd->disk = disk;
2681	disk->major = pktdev_major;
2682	disk->first_minor = idx;
2683	disk->fops = &pktcdvd_ops;
2684	disk->flags = GENHD_FL_REMOVABLE;
2685	strcpy(disk->disk_name, pd->name);
2686	disk->private_data = pd;
2687	disk->queue = blk_alloc_queue(NUMA_NO_NODE);
2688	if (!disk->queue)
2689		goto out_mem2;
2690
2691	pd->pkt_dev = MKDEV(pktdev_major, idx);
2692	ret = pkt_new_dev(pd, dev);
2693	if (ret)
2694		goto out_mem2;
2695
2696	/* inherit events of the host device */
2697	disk->events = pd->bdev->bd_disk->events;
2698
2699	add_disk(disk);
2700
2701	pkt_sysfs_dev_new(pd);
2702	pkt_debugfs_dev_new(pd);
2703
2704	pkt_devs[idx] = pd;
2705	if (pkt_dev)
2706		*pkt_dev = pd->pkt_dev;
2707
2708	mutex_unlock(&ctl_mutex);
2709	return 0;
2710
2711out_mem2:
2712	put_disk(disk);
2713out_mem:
2714	mempool_exit(&pd->rb_pool);
2715	kfree(pd);
2716out_mutex:
2717	mutex_unlock(&ctl_mutex);
2718	pr_err("setup of pktcdvd device failed\n");
2719	return ret;
2720}
2721
2722/*
2723 * Tear down mapping from pktcdvd device to CD-ROM device.
2724 */
2725static int pkt_remove_dev(dev_t pkt_dev)
2726{
2727	struct pktcdvd_device *pd;
2728	int idx;
2729	int ret = 0;
2730
2731	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2732
2733	for (idx = 0; idx < MAX_WRITERS; idx++) {
2734		pd = pkt_devs[idx];
2735		if (pd && (pd->pkt_dev == pkt_dev))
2736			break;
2737	}
2738	if (idx == MAX_WRITERS) {
2739		pr_debug("dev not setup\n");
2740		ret = -ENXIO;
2741		goto out;
2742	}
2743
2744	if (pd->refcnt > 0) {
2745		ret = -EBUSY;
2746		goto out;
2747	}
2748	if (!IS_ERR(pd->cdrw.thread))
2749		kthread_stop(pd->cdrw.thread);
2750
2751	pkt_devs[idx] = NULL;
2752
2753	pkt_debugfs_dev_remove(pd);
2754	pkt_sysfs_dev_remove(pd);
2755
2756	blkdev_put(pd->bdev, FMODE_READ | FMODE_NDELAY);
2757
2758	remove_proc_entry(pd->name, pkt_proc);
2759	pkt_dbg(1, pd, "writer unmapped\n");
2760
2761	del_gendisk(pd->disk);
2762	blk_cleanup_queue(pd->disk->queue);
2763	put_disk(pd->disk);
2764
2765	mempool_exit(&pd->rb_pool);
2766	kfree(pd);
2767
2768	/* This is safe: open() is still holding a reference. */
2769	module_put(THIS_MODULE);
2770
2771out:
2772	mutex_unlock(&ctl_mutex);
2773	return ret;
2774}
2775
2776static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
2777{
2778	struct pktcdvd_device *pd;
2779
2780	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2781
2782	pd = pkt_find_dev_from_minor(ctrl_cmd->dev_index);
2783	if (pd) {
2784		ctrl_cmd->dev = new_encode_dev(pd->bdev->bd_dev);
2785		ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
2786	} else {
2787		ctrl_cmd->dev = 0;
2788		ctrl_cmd->pkt_dev = 0;
2789	}
2790	ctrl_cmd->num_devices = MAX_WRITERS;
2791
2792	mutex_unlock(&ctl_mutex);
2793}
2794
2795static long pkt_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2796{
2797	void __user *argp = (void __user *)arg;
2798	struct pkt_ctrl_command ctrl_cmd;
2799	int ret = 0;
2800	dev_t pkt_dev = 0;
2801
2802	if (cmd != PACKET_CTRL_CMD)
2803		return -ENOTTY;
2804
2805	if (copy_from_user(&ctrl_cmd, argp, sizeof(struct pkt_ctrl_command)))
2806		return -EFAULT;
2807
2808	switch (ctrl_cmd.command) {
2809	case PKT_CTRL_CMD_SETUP:
2810		if (!capable(CAP_SYS_ADMIN))
2811			return -EPERM;
2812		ret = pkt_setup_dev(new_decode_dev(ctrl_cmd.dev), &pkt_dev);
2813		ctrl_cmd.pkt_dev = new_encode_dev(pkt_dev);
2814		break;
2815	case PKT_CTRL_CMD_TEARDOWN:
2816		if (!capable(CAP_SYS_ADMIN))
2817			return -EPERM;
2818		ret = pkt_remove_dev(new_decode_dev(ctrl_cmd.pkt_dev));
2819		break;
2820	case PKT_CTRL_CMD_STATUS:
2821		pkt_get_status(&ctrl_cmd);
2822		break;
2823	default:
2824		return -ENOTTY;
2825	}
2826
2827	if (copy_to_user(argp, &ctrl_cmd, sizeof(struct pkt_ctrl_command)))
2828		return -EFAULT;
2829	return ret;
2830}
2831
2832#ifdef CONFIG_COMPAT
2833static long pkt_ctl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2834{
2835	return pkt_ctl_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
2836}
2837#endif
2838
2839static const struct file_operations pkt_ctl_fops = {
2840	.open		= nonseekable_open,
2841	.unlocked_ioctl	= pkt_ctl_ioctl,
2842#ifdef CONFIG_COMPAT
2843	.compat_ioctl	= pkt_ctl_compat_ioctl,
2844#endif
2845	.owner		= THIS_MODULE,
2846	.llseek		= no_llseek,
2847};
2848
2849static struct miscdevice pkt_misc = {
2850	.minor 		= MISC_DYNAMIC_MINOR,
2851	.name  		= DRIVER_NAME,
2852	.nodename	= "pktcdvd/control",
2853	.fops  		= &pkt_ctl_fops
2854};
2855
2856static int __init pkt_init(void)
2857{
2858	int ret;
2859
2860	mutex_init(&ctl_mutex);
2861
2862	ret = mempool_init_kmalloc_pool(&psd_pool, PSD_POOL_SIZE,
2863				    sizeof(struct packet_stacked_data));
2864	if (ret)
2865		return ret;
2866	ret = bioset_init(&pkt_bio_set, BIO_POOL_SIZE, 0, 0);
2867	if (ret) {
2868		mempool_exit(&psd_pool);
2869		return ret;
2870	}
2871
2872	ret = register_blkdev(pktdev_major, DRIVER_NAME);
2873	if (ret < 0) {
2874		pr_err("unable to register block device\n");
2875		goto out2;
2876	}
2877	if (!pktdev_major)
2878		pktdev_major = ret;
2879
2880	ret = pkt_sysfs_init();
2881	if (ret)
2882		goto out;
2883
2884	pkt_debugfs_init();
2885
2886	ret = misc_register(&pkt_misc);
2887	if (ret) {
2888		pr_err("unable to register misc device\n");
2889		goto out_misc;
2890	}
2891
2892	pkt_proc = proc_mkdir("driver/"DRIVER_NAME, NULL);
2893
2894	return 0;
2895
2896out_misc:
2897	pkt_debugfs_cleanup();
2898	pkt_sysfs_cleanup();
2899out:
2900	unregister_blkdev(pktdev_major, DRIVER_NAME);
2901out2:
2902	mempool_exit(&psd_pool);
2903	bioset_exit(&pkt_bio_set);
2904	return ret;
2905}
2906
2907static void __exit pkt_exit(void)
2908{
2909	remove_proc_entry("driver/"DRIVER_NAME, NULL);
2910	misc_deregister(&pkt_misc);
2911
2912	pkt_debugfs_cleanup();
2913	pkt_sysfs_cleanup();
2914
2915	unregister_blkdev(pktdev_major, DRIVER_NAME);
2916	mempool_exit(&psd_pool);
2917	bioset_exit(&pkt_bio_set);
2918}
2919
2920MODULE_DESCRIPTION("Packet writing layer for CD/DVD drives");
2921MODULE_AUTHOR("Jens Axboe <axboe@suse.de>");
2922MODULE_LICENSE("GPL");
2923
2924module_init(pkt_init);
2925module_exit(pkt_exit);
2926