2 * dcssblk.c -- the S/390 block driver for dcss memory
4 * Authors: Carsten Otte, Stefan Weinhuber, Gerald Schaefer
7 #define KMSG_COMPONENT "dcssblk"
8 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
10 #include <linux/module.h>
11 #include <linux/moduleparam.h>
12 #include <linux/ctype.h>
13 #include <linux/errno.h>
14 #include <linux/init.h>
15 #include <linux/slab.h>
16 #include <linux/blkdev.h>
17 #include <linux/completion.h>
18 #include <linux/interrupt.h>
19 #include <linux/platform_device.h>
20 #include <asm/extmem.h>
23 #define DCSSBLK_NAME "dcssblk"
24 #define DCSSBLK_MINORS_PER_DISK 1
25 #define DCSSBLK_PARM_LEN 400
26 #define DCSS_BUS_ID_SIZE 20
28 static int dcssblk_open(struct block_device *bdev, fmode_t mode);
29 static void dcssblk_release(struct gendisk *disk, fmode_t mode);
30 static blk_qc_t dcssblk_make_request(struct request_queue *q,
32 static long dcssblk_direct_access(struct block_device *bdev, sector_t secnum,
33 void __pmem **kaddr, unsigned long *pfn);
35 static char dcssblk_segments[DCSSBLK_PARM_LEN] = "\0";
37 static int dcssblk_major;
38 static const struct block_device_operations dcssblk_devops = {
41 .release = dcssblk_release,
42 .direct_access = dcssblk_direct_access,
45 struct dcssblk_dev_info {
48 char segment_name[DCSS_BUS_ID_SIZE];
54 unsigned char save_pending;
55 unsigned char is_shared;
56 struct request_queue *dcssblk_queue;
58 struct list_head seg_list;
63 char segment_name[DCSS_BUS_ID_SIZE];
69 static ssize_t dcssblk_add_store(struct device * dev, struct device_attribute *attr, const char * buf,
71 static ssize_t dcssblk_remove_store(struct device * dev, struct device_attribute *attr, const char * buf,
74 static DEVICE_ATTR(add, S_IWUSR, NULL, dcssblk_add_store);
75 static DEVICE_ATTR(remove, S_IWUSR, NULL, dcssblk_remove_store);
77 static struct device *dcssblk_root_dev;
79 static LIST_HEAD(dcssblk_devices);
80 static struct rw_semaphore dcssblk_devices_sem;
83 * release function for segment device.
86 dcssblk_release_segment(struct device *dev)
88 struct dcssblk_dev_info *dev_info;
89 struct segment_info *entry, *temp;
91 dev_info = container_of(dev, struct dcssblk_dev_info, dev);
92 list_for_each_entry_safe(entry, temp, &dev_info->seg_list, lh) {
97 module_put(THIS_MODULE);
101 * get a minor number. needs to be called with
102 * down_write(&dcssblk_devices_sem) and the
103 * device needs to be enqueued before the semaphore is
107 dcssblk_assign_free_minor(struct dcssblk_dev_info *dev_info)
110 struct dcssblk_dev_info *entry;
112 if (dev_info == NULL)
114 for (minor = 0; minor < (1<<MINORBITS); minor++) {
116 // test if minor available
117 list_for_each_entry(entry, &dcssblk_devices, lh)
118 if (minor == entry->gd->first_minor)
120 if (!found) break; // got unused minor
124 dev_info->gd->first_minor = minor;
129 * get the struct dcssblk_dev_info from dcssblk_devices
130 * for the given name.
131 * down_read(&dcssblk_devices_sem) must be held.
133 static struct dcssblk_dev_info *
134 dcssblk_get_device_by_name(char *name)
136 struct dcssblk_dev_info *entry;
138 list_for_each_entry(entry, &dcssblk_devices, lh) {
139 if (!strcmp(name, entry->segment_name)) {
147 * get the struct segment_info from seg_list
148 * for the given name.
149 * down_read(&dcssblk_devices_sem) must be held.
151 static struct segment_info *
152 dcssblk_get_segment_by_name(char *name)
154 struct dcssblk_dev_info *dev_info;
155 struct segment_info *entry;
157 list_for_each_entry(dev_info, &dcssblk_devices, lh) {
158 list_for_each_entry(entry, &dev_info->seg_list, lh) {
159 if (!strcmp(name, entry->segment_name))
167 * get the highest address of the multi-segment block.
170 dcssblk_find_highest_addr(struct dcssblk_dev_info *dev_info)
172 unsigned long highest_addr;
173 struct segment_info *entry;
176 list_for_each_entry(entry, &dev_info->seg_list, lh) {
177 if (highest_addr < entry->end)
178 highest_addr = entry->end;
184 * get the lowest address of the multi-segment block.
187 dcssblk_find_lowest_addr(struct dcssblk_dev_info *dev_info)
190 unsigned long lowest_addr;
191 struct segment_info *entry;
195 list_for_each_entry(entry, &dev_info->seg_list, lh) {
196 if (set_first == 0) {
197 lowest_addr = entry->start;
200 if (lowest_addr > entry->start)
201 lowest_addr = entry->start;
208 * Check continuity of segments.
211 dcssblk_is_continuous(struct dcssblk_dev_info *dev_info)
214 struct segment_info *sort_list, *entry, temp;
216 if (dev_info->num_of_segments <= 1)
220 sizeof(struct segment_info) * dev_info->num_of_segments,
222 if (sort_list == NULL)
225 list_for_each_entry(entry, &dev_info->seg_list, lh) {
226 memcpy(&sort_list[i], entry, sizeof(struct segment_info));
231 for (i = 0; i < dev_info->num_of_segments; i++)
232 for (j = 0; j < dev_info->num_of_segments; j++)
233 if (sort_list[j].start > sort_list[i].start) {
234 memcpy(&temp, &sort_list[i],
235 sizeof(struct segment_info));
236 memcpy(&sort_list[i], &sort_list[j],
237 sizeof(struct segment_info));
238 memcpy(&sort_list[j], &temp,
239 sizeof(struct segment_info));
242 /* check continuity */
243 for (i = 0; i < dev_info->num_of_segments - 1; i++) {
244 if ((sort_list[i].end + 1) != sort_list[i+1].start) {
245 pr_err("Adjacent DCSSs %s and %s are not "
246 "contiguous\n", sort_list[i].segment_name,
247 sort_list[i+1].segment_name);
251 /* EN and EW are allowed in a block device */
252 if (sort_list[i].segment_type != sort_list[i+1].segment_type) {
253 if (!(sort_list[i].segment_type & SEGMENT_EXCLUSIVE) ||
254 (sort_list[i].segment_type == SEG_TYPE_ER) ||
255 !(sort_list[i+1].segment_type &
256 SEGMENT_EXCLUSIVE) ||
257 (sort_list[i+1].segment_type == SEG_TYPE_ER)) {
258 pr_err("DCSS %s and DCSS %s have "
259 "incompatible types\n",
260 sort_list[i].segment_name,
261 sort_list[i+1].segment_name);
277 dcssblk_load_segment(char *name, struct segment_info **seg_info)
281 /* already loaded? */
282 down_read(&dcssblk_devices_sem);
283 *seg_info = dcssblk_get_segment_by_name(name);
284 up_read(&dcssblk_devices_sem);
285 if (*seg_info != NULL)
288 /* get a struct segment_info */
289 *seg_info = kzalloc(sizeof(struct segment_info), GFP_KERNEL);
290 if (*seg_info == NULL)
293 strcpy((*seg_info)->segment_name, name);
295 /* load the segment */
296 rc = segment_load(name, SEGMENT_SHARED,
297 &(*seg_info)->start, &(*seg_info)->end);
299 segment_warning(rc, (*seg_info)->segment_name);
302 INIT_LIST_HEAD(&(*seg_info)->lh);
303 (*seg_info)->segment_type = rc;
309 * device attribute for switching shared/nonshared (exclusive)
310 * operation (show + store)
313 dcssblk_shared_show(struct device *dev, struct device_attribute *attr, char *buf)
315 struct dcssblk_dev_info *dev_info;
317 dev_info = container_of(dev, struct dcssblk_dev_info, dev);
318 return sprintf(buf, dev_info->is_shared ? "1\n" : "0\n");
322 dcssblk_shared_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count)
324 struct dcssblk_dev_info *dev_info;
325 struct segment_info *entry, *temp;
328 if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0'))
330 down_write(&dcssblk_devices_sem);
331 dev_info = container_of(dev, struct dcssblk_dev_info, dev);
332 if (atomic_read(&dev_info->use_count)) {
336 if (inbuf[0] == '1') {
337 /* reload segments in shared mode */
338 list_for_each_entry(entry, &dev_info->seg_list, lh) {
339 rc = segment_modify_shared(entry->segment_name,
342 BUG_ON(rc == -EINVAL);
347 dev_info->is_shared = 1;
348 switch (dev_info->segment_type) {
352 set_disk_ro(dev_info->gd, 1);
354 } else if (inbuf[0] == '0') {
355 /* reload segments in exclusive mode */
356 if (dev_info->segment_type == SEG_TYPE_SC) {
357 pr_err("DCSS %s is of type SC and cannot be "
358 "loaded as exclusive-writable\n",
359 dev_info->segment_name);
363 list_for_each_entry(entry, &dev_info->seg_list, lh) {
364 rc = segment_modify_shared(entry->segment_name,
367 BUG_ON(rc == -EINVAL);
372 dev_info->is_shared = 0;
373 set_disk_ro(dev_info->gd, 0);
382 pr_err("DCSS device %s is removed after a failed access mode "
383 "change\n", dev_info->segment_name);
385 list_for_each_entry(entry, &dev_info->seg_list, lh) {
387 segment_unload(entry->segment_name);
389 list_del(&dev_info->lh);
391 del_gendisk(dev_info->gd);
392 blk_cleanup_queue(dev_info->dcssblk_queue);
393 dev_info->gd->queue = NULL;
394 put_disk(dev_info->gd);
395 up_write(&dcssblk_devices_sem);
397 if (device_remove_file_self(dev, attr)) {
398 device_unregister(dev);
403 up_write(&dcssblk_devices_sem);
406 static DEVICE_ATTR(shared, S_IWUSR | S_IRUSR, dcssblk_shared_show,
407 dcssblk_shared_store);
410 * device attribute for save operation on current copy
411 * of the segment. If the segment is busy, saving will
412 * become pending until it gets released, which can be
413 * undone by storing a non-true value to this entry.
417 dcssblk_save_show(struct device *dev, struct device_attribute *attr, char *buf)
419 struct dcssblk_dev_info *dev_info;
421 dev_info = container_of(dev, struct dcssblk_dev_info, dev);
422 return sprintf(buf, dev_info->save_pending ? "1\n" : "0\n");
426 dcssblk_save_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count)
428 struct dcssblk_dev_info *dev_info;
429 struct segment_info *entry;
431 if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0'))
433 dev_info = container_of(dev, struct dcssblk_dev_info, dev);
435 down_write(&dcssblk_devices_sem);
436 if (inbuf[0] == '1') {
437 if (atomic_read(&dev_info->use_count) == 0) {
438 // device is idle => we save immediately
439 pr_info("All DCSSs that map to device %s are "
440 "saved\n", dev_info->segment_name);
441 list_for_each_entry(entry, &dev_info->seg_list, lh) {
442 if (entry->segment_type == SEG_TYPE_EN ||
443 entry->segment_type == SEG_TYPE_SN)
444 pr_warn("DCSS %s is of type SN or EN"
445 " and cannot be saved\n",
446 entry->segment_name);
448 segment_save(entry->segment_name);
451 // device is busy => we save it when it becomes
452 // idle in dcssblk_release
453 pr_info("Device %s is in use, its DCSSs will be "
454 "saved when it becomes idle\n",
455 dev_info->segment_name);
456 dev_info->save_pending = 1;
458 } else if (inbuf[0] == '0') {
459 if (dev_info->save_pending) {
460 // device is busy & the user wants to undo his save
462 dev_info->save_pending = 0;
463 pr_info("A pending save request for device %s "
464 "has been canceled\n",
465 dev_info->segment_name);
468 up_write(&dcssblk_devices_sem);
471 up_write(&dcssblk_devices_sem);
474 static DEVICE_ATTR(save, S_IWUSR | S_IRUSR, dcssblk_save_show,
478 * device attribute for showing all segments in a device
481 dcssblk_seglist_show(struct device *dev, struct device_attribute *attr,
486 struct dcssblk_dev_info *dev_info;
487 struct segment_info *entry;
489 down_read(&dcssblk_devices_sem);
490 dev_info = container_of(dev, struct dcssblk_dev_info, dev);
493 list_for_each_entry(entry, &dev_info->seg_list, lh) {
494 strcpy(&buf[i], entry->segment_name);
495 i += strlen(entry->segment_name);
499 up_read(&dcssblk_devices_sem);
502 static DEVICE_ATTR(seglist, S_IRUSR, dcssblk_seglist_show, NULL);
504 static struct attribute *dcssblk_dev_attrs[] = {
505 &dev_attr_shared.attr,
507 &dev_attr_seglist.attr,
510 static struct attribute_group dcssblk_dev_attr_group = {
511 .attrs = dcssblk_dev_attrs,
513 static const struct attribute_group *dcssblk_dev_attr_groups[] = {
514 &dcssblk_dev_attr_group,
519 * device attribute for adding devices
522 dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
524 int rc, i, j, num_of_segments;
525 struct dcssblk_dev_info *dev_info;
526 struct segment_info *seg_info, *temp;
528 unsigned long seg_byte_size;
532 if (dev != dcssblk_root_dev) {
536 if ((count < 1) || (buf[0] == '\0') || (buf[0] == '\n')) {
541 local_buf = kmalloc(count + 1, GFP_KERNEL);
542 if (local_buf == NULL) {
551 for (i = 0; (i < count && (buf[i] != '\0') && (buf[i] != '\n')); i++) {
552 for (j = i; j < count &&
555 (buf[j] != '\n'); j++) {
556 local_buf[j-i] = toupper(buf[j]);
558 local_buf[j-i] = '\0';
559 if (((j - i) == 0) || ((j - i) > 8)) {
564 rc = dcssblk_load_segment(local_buf, &seg_info);
568 * get a struct dcssblk_dev_info
570 if (num_of_segments == 0) {
571 dev_info = kzalloc(sizeof(struct dcssblk_dev_info),
573 if (dev_info == NULL) {
577 strcpy(dev_info->segment_name, local_buf);
578 dev_info->segment_type = seg_info->segment_type;
579 INIT_LIST_HEAD(&dev_info->seg_list);
581 list_add_tail(&seg_info->lh, &dev_info->seg_list);
585 if ((buf[j] == '\0') || (buf[j] == '\n'))
589 /* no trailing colon at the end of the input */
590 if ((i > 0) && (buf[i-1] == ':')) {
594 strlcpy(local_buf, buf, i + 1);
595 dev_info->num_of_segments = num_of_segments;
596 rc = dcssblk_is_continuous(dev_info);
600 dev_info->start = dcssblk_find_lowest_addr(dev_info);
601 dev_info->end = dcssblk_find_highest_addr(dev_info);
603 dev_set_name(&dev_info->dev, "%s", dev_info->segment_name);
604 dev_info->dev.release = dcssblk_release_segment;
605 dev_info->dev.groups = dcssblk_dev_attr_groups;
606 INIT_LIST_HEAD(&dev_info->lh);
607 dev_info->gd = alloc_disk(DCSSBLK_MINORS_PER_DISK);
608 if (dev_info->gd == NULL) {
612 dev_info->gd->major = dcssblk_major;
613 dev_info->gd->fops = &dcssblk_devops;
614 dev_info->dcssblk_queue = blk_alloc_queue(GFP_KERNEL);
615 dev_info->gd->queue = dev_info->dcssblk_queue;
616 dev_info->gd->private_data = dev_info;
617 dev_info->gd->driverfs_dev = &dev_info->dev;
618 blk_queue_make_request(dev_info->dcssblk_queue, dcssblk_make_request);
619 blk_queue_logical_block_size(dev_info->dcssblk_queue, 4096);
621 seg_byte_size = (dev_info->end - dev_info->start + 1);
622 set_capacity(dev_info->gd, seg_byte_size >> 9); // size in sectors
623 pr_info("Loaded %s with total size %lu bytes and capacity %lu "
624 "sectors\n", local_buf, seg_byte_size, seg_byte_size >> 9);
626 dev_info->save_pending = 0;
627 dev_info->is_shared = 1;
628 dev_info->dev.parent = dcssblk_root_dev;
631 *get minor, add to list
633 down_write(&dcssblk_devices_sem);
634 if (dcssblk_get_segment_by_name(local_buf)) {
638 rc = dcssblk_assign_free_minor(dev_info);
641 sprintf(dev_info->gd->disk_name, "dcssblk%d",
642 dev_info->gd->first_minor);
643 list_add_tail(&dev_info->lh, &dcssblk_devices);
645 if (!try_module_get(THIS_MODULE)) {
650 * register the device
652 rc = device_register(&dev_info->dev);
656 get_device(&dev_info->dev);
657 add_disk(dev_info->gd);
659 switch (dev_info->segment_type) {
663 set_disk_ro(dev_info->gd,1);
666 set_disk_ro(dev_info->gd,0);
669 up_write(&dcssblk_devices_sem);
674 list_del(&dev_info->lh);
675 blk_cleanup_queue(dev_info->dcssblk_queue);
676 dev_info->gd->queue = NULL;
677 put_disk(dev_info->gd);
678 list_for_each_entry(seg_info, &dev_info->seg_list, lh) {
679 segment_unload(seg_info->segment_name);
681 put_device(&dev_info->dev);
682 up_write(&dcssblk_devices_sem);
685 list_del(&dev_info->lh);
687 blk_cleanup_queue(dev_info->dcssblk_queue);
688 dev_info->gd->queue = NULL;
689 put_disk(dev_info->gd);
690 up_write(&dcssblk_devices_sem);
692 if (dev_info == NULL)
694 list_for_each_entry_safe(seg_info, temp, &dev_info->seg_list, lh) {
695 list_del(&seg_info->lh);
696 segment_unload(seg_info->segment_name);
707 * device attribute for removing devices
710 dcssblk_remove_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
712 struct dcssblk_dev_info *dev_info;
713 struct segment_info *entry;
717 if (dev != dcssblk_root_dev) {
720 local_buf = kmalloc(count + 1, GFP_KERNEL);
721 if (local_buf == NULL) {
727 for (i = 0; (i < count && (*(buf+i)!='\0') && (*(buf+i)!='\n')); i++) {
728 local_buf[i] = toupper(buf[i]);
731 if ((i == 0) || (i > 8)) {
736 down_write(&dcssblk_devices_sem);
737 dev_info = dcssblk_get_device_by_name(local_buf);
738 if (dev_info == NULL) {
739 up_write(&dcssblk_devices_sem);
740 pr_warning("Device %s cannot be removed because it is not a "
741 "known device\n", local_buf);
745 if (atomic_read(&dev_info->use_count) != 0) {
746 up_write(&dcssblk_devices_sem);
747 pr_warning("Device %s cannot be removed while it is in "
753 list_del(&dev_info->lh);
754 del_gendisk(dev_info->gd);
755 blk_cleanup_queue(dev_info->dcssblk_queue);
756 dev_info->gd->queue = NULL;
757 put_disk(dev_info->gd);
758 device_unregister(&dev_info->dev);
760 /* unload all related segments */
761 list_for_each_entry(entry, &dev_info->seg_list, lh)
762 segment_unload(entry->segment_name);
764 put_device(&dev_info->dev);
765 up_write(&dcssblk_devices_sem);
774 dcssblk_open(struct block_device *bdev, fmode_t mode)
776 struct dcssblk_dev_info *dev_info;
779 dev_info = bdev->bd_disk->private_data;
780 if (NULL == dev_info) {
784 atomic_inc(&dev_info->use_count);
785 bdev->bd_block_size = 4096;
792 dcssblk_release(struct gendisk *disk, fmode_t mode)
794 struct dcssblk_dev_info *dev_info = disk->private_data;
795 struct segment_info *entry;
801 down_write(&dcssblk_devices_sem);
802 if (atomic_dec_and_test(&dev_info->use_count)
803 && (dev_info->save_pending)) {
804 pr_info("Device %s has become idle and is being saved "
805 "now\n", dev_info->segment_name);
806 list_for_each_entry(entry, &dev_info->seg_list, lh) {
807 if (entry->segment_type == SEG_TYPE_EN ||
808 entry->segment_type == SEG_TYPE_SN)
809 pr_warn("DCSS %s is of type SN or EN and cannot"
810 " be saved\n", entry->segment_name);
812 segment_save(entry->segment_name);
814 dev_info->save_pending = 0;
816 up_write(&dcssblk_devices_sem);
820 dcssblk_make_request(struct request_queue *q, struct bio *bio)
822 struct dcssblk_dev_info *dev_info;
824 struct bvec_iter iter;
826 unsigned long page_addr;
827 unsigned long source_addr;
828 unsigned long bytes_done;
830 blk_queue_split(q, &bio, q->bio_split);
833 dev_info = bio->bi_bdev->bd_disk->private_data;
834 if (dev_info == NULL)
836 if ((bio->bi_iter.bi_sector & 7) != 0 ||
837 (bio->bi_iter.bi_size & 4095) != 0)
838 /* Request is not page-aligned. */
840 if (bio_end_sector(bio) > get_capacity(bio->bi_bdev->bd_disk)) {
841 /* Request beyond end of DCSS segment. */
844 /* verify data transfer direction */
845 if (dev_info->is_shared) {
846 switch (dev_info->segment_type) {
850 /* cannot write to these segments */
851 if (bio_data_dir(bio) == WRITE) {
852 pr_warning("Writing to %s failed because it "
853 "is a read-only device\n",
854 dev_name(&dev_info->dev));
860 index = (bio->bi_iter.bi_sector >> 3);
861 bio_for_each_segment(bvec, bio, iter) {
862 page_addr = (unsigned long)
863 page_address(bvec.bv_page) + bvec.bv_offset;
864 source_addr = dev_info->start + (index<<12) + bytes_done;
865 if (unlikely((page_addr & 4095) != 0) || (bvec.bv_len & 4095) != 0)
868 if (bio_data_dir(bio) == READ) {
869 memcpy((void*)page_addr, (void*)source_addr,
872 memcpy((void*)source_addr, (void*)page_addr,
875 bytes_done += bvec.bv_len;
878 return BLK_QC_T_NONE;
881 return BLK_QC_T_NONE;
885 dcssblk_direct_access (struct block_device *bdev, sector_t secnum,
886 void __pmem **kaddr, unsigned long *pfn)
888 struct dcssblk_dev_info *dev_info;
889 unsigned long offset, dev_sz;
892 dev_info = bdev->bd_disk->private_data;
895 dev_sz = dev_info->end - dev_info->start + 1;
896 offset = secnum * 512;
897 addr = (void *) (dev_info->start + offset);
898 *pfn = virt_to_phys(addr) >> PAGE_SHIFT;
899 *kaddr = (void __pmem *) addr;
901 return dev_sz - offset;
905 dcssblk_check_params(void)
908 char buf[DCSSBLK_PARM_LEN + 1];
909 struct dcssblk_dev_info *dev_info;
911 for (i = 0; (i < DCSSBLK_PARM_LEN) && (dcssblk_segments[i] != '\0');
913 for (j = i; (j < DCSSBLK_PARM_LEN) &&
914 (dcssblk_segments[j] != ',') &&
915 (dcssblk_segments[j] != '\0') &&
916 (dcssblk_segments[j] != '('); j++)
918 buf[j-i] = dcssblk_segments[j];
921 rc = dcssblk_add_store(dcssblk_root_dev, NULL, buf, j-i);
922 if ((rc >= 0) && (dcssblk_segments[j] == '(')) {
923 for (k = 0; (buf[k] != ':') && (buf[k] != '\0'); k++)
924 buf[k] = toupper(buf[k]);
926 if (!strncmp(&dcssblk_segments[j], "(local)", 7)) {
927 down_read(&dcssblk_devices_sem);
928 dev_info = dcssblk_get_device_by_name(buf);
929 up_read(&dcssblk_devices_sem);
931 dcssblk_shared_store(&dev_info->dev,
935 while ((dcssblk_segments[j] != ',') &&
936 (dcssblk_segments[j] != '\0'))
940 if (dcssblk_segments[j] == '\0')
949 static int dcssblk_freeze(struct device *dev)
951 struct dcssblk_dev_info *dev_info;
954 list_for_each_entry(dev_info, &dcssblk_devices, lh) {
955 switch (dev_info->segment_type) {
959 if (!dev_info->is_shared)
970 pr_err("Suspending the system failed because DCSS device %s "
972 dev_info->segment_name);
976 static int dcssblk_restore(struct device *dev)
978 struct dcssblk_dev_info *dev_info;
979 struct segment_info *entry;
980 unsigned long start, end;
983 list_for_each_entry(dev_info, &dcssblk_devices, lh) {
984 list_for_each_entry(entry, &dev_info->seg_list, lh) {
985 segment_unload(entry->segment_name);
986 rc = segment_load(entry->segment_name, SEGMENT_SHARED,
989 // TODO in_use check ?
990 segment_warning(rc, entry->segment_name);
993 if (start != entry->start || end != entry->end) {
994 pr_err("The address range of DCSS %s changed "
995 "while the system was suspended\n",
996 entry->segment_name);
1003 panic("fatal dcssblk resume error\n");
1006 static int dcssblk_thaw(struct device *dev)
1011 static const struct dev_pm_ops dcssblk_pm_ops = {
1012 .freeze = dcssblk_freeze,
1013 .thaw = dcssblk_thaw,
1014 .restore = dcssblk_restore,
1017 static struct platform_driver dcssblk_pdrv = {
1020 .pm = &dcssblk_pm_ops,
1024 static struct platform_device *dcssblk_pdev;
1028 * The init/exit functions.
1033 platform_device_unregister(dcssblk_pdev);
1034 platform_driver_unregister(&dcssblk_pdrv);
1035 root_device_unregister(dcssblk_root_dev);
1036 unregister_blkdev(dcssblk_major, DCSSBLK_NAME);
1044 rc = platform_driver_register(&dcssblk_pdrv);
1048 dcssblk_pdev = platform_device_register_simple("dcssblk", -1, NULL,
1050 if (IS_ERR(dcssblk_pdev)) {
1051 rc = PTR_ERR(dcssblk_pdev);
1055 dcssblk_root_dev = root_device_register("dcssblk");
1056 if (IS_ERR(dcssblk_root_dev)) {
1057 rc = PTR_ERR(dcssblk_root_dev);
1060 rc = device_create_file(dcssblk_root_dev, &dev_attr_add);
1063 rc = device_create_file(dcssblk_root_dev, &dev_attr_remove);
1066 rc = register_blkdev(0, DCSSBLK_NAME);
1070 init_rwsem(&dcssblk_devices_sem);
1072 dcssblk_check_params();
1076 root_device_unregister(dcssblk_root_dev);
1078 platform_device_unregister(dcssblk_pdev);
1080 platform_driver_unregister(&dcssblk_pdrv);
1084 module_init(dcssblk_init);
1085 module_exit(dcssblk_exit);
1087 module_param_string(segments, dcssblk_segments, DCSSBLK_PARM_LEN, 0444);
1088 MODULE_PARM_DESC(segments, "Name of DCSS segment(s) to be loaded, "
1089 "comma-separated list, names in each set separated "
1090 "by commas are separated by colons, each set contains "
1091 "names of contiguous segments and each name max. 8 chars.\n"
1092 "Adding \"(local)\" to the end of each set equals echoing 0 "
1093 "to /sys/devices/dcssblk/<device name>/shared after loading "
1094 "the contiguous segments - \n"
1095 "e.g. segments=\"mydcss1,mydcss2:mydcss3,mydcss4(local)\"");
1097 MODULE_LICENSE("GPL");