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 void dcssblk_make_request(struct request_queue *q, struct bio *bio);
31 static long dcssblk_direct_access(struct block_device *bdev, sector_t secnum,
32 void **kaddr, unsigned long *pfn, long size);
34 static char dcssblk_segments[DCSSBLK_PARM_LEN] = "\0";
36 static int dcssblk_major;
37 static const struct block_device_operations dcssblk_devops = {
40 .release = dcssblk_release,
41 .direct_access = dcssblk_direct_access,
44 struct dcssblk_dev_info {
47 char segment_name[DCSS_BUS_ID_SIZE];
53 unsigned char save_pending;
54 unsigned char is_shared;
55 struct request_queue *dcssblk_queue;
57 struct list_head seg_list;
62 char segment_name[DCSS_BUS_ID_SIZE];
68 static ssize_t dcssblk_add_store(struct device * dev, struct device_attribute *attr, const char * buf,
70 static ssize_t dcssblk_remove_store(struct device * dev, struct device_attribute *attr, const char * buf,
73 static DEVICE_ATTR(add, S_IWUSR, NULL, dcssblk_add_store);
74 static DEVICE_ATTR(remove, S_IWUSR, NULL, dcssblk_remove_store);
76 static struct device *dcssblk_root_dev;
78 static LIST_HEAD(dcssblk_devices);
79 static struct rw_semaphore dcssblk_devices_sem;
82 * release function for segment device.
85 dcssblk_release_segment(struct device *dev)
87 struct dcssblk_dev_info *dev_info;
88 struct segment_info *entry, *temp;
90 dev_info = container_of(dev, struct dcssblk_dev_info, dev);
91 list_for_each_entry_safe(entry, temp, &dev_info->seg_list, lh) {
96 module_put(THIS_MODULE);
100 * get a minor number. needs to be called with
101 * down_write(&dcssblk_devices_sem) and the
102 * device needs to be enqueued before the semaphore is
106 dcssblk_assign_free_minor(struct dcssblk_dev_info *dev_info)
109 struct dcssblk_dev_info *entry;
111 if (dev_info == NULL)
113 for (minor = 0; minor < (1<<MINORBITS); minor++) {
115 // test if minor available
116 list_for_each_entry(entry, &dcssblk_devices, lh)
117 if (minor == entry->gd->first_minor)
119 if (!found) break; // got unused minor
123 dev_info->gd->first_minor = minor;
128 * get the struct dcssblk_dev_info from dcssblk_devices
129 * for the given name.
130 * down_read(&dcssblk_devices_sem) must be held.
132 static struct dcssblk_dev_info *
133 dcssblk_get_device_by_name(char *name)
135 struct dcssblk_dev_info *entry;
137 list_for_each_entry(entry, &dcssblk_devices, lh) {
138 if (!strcmp(name, entry->segment_name)) {
146 * get the struct segment_info from seg_list
147 * for the given name.
148 * down_read(&dcssblk_devices_sem) must be held.
150 static struct segment_info *
151 dcssblk_get_segment_by_name(char *name)
153 struct dcssblk_dev_info *dev_info;
154 struct segment_info *entry;
156 list_for_each_entry(dev_info, &dcssblk_devices, lh) {
157 list_for_each_entry(entry, &dev_info->seg_list, lh) {
158 if (!strcmp(name, entry->segment_name))
166 * get the highest address of the multi-segment block.
169 dcssblk_find_highest_addr(struct dcssblk_dev_info *dev_info)
171 unsigned long highest_addr;
172 struct segment_info *entry;
175 list_for_each_entry(entry, &dev_info->seg_list, lh) {
176 if (highest_addr < entry->end)
177 highest_addr = entry->end;
183 * get the lowest address of the multi-segment block.
186 dcssblk_find_lowest_addr(struct dcssblk_dev_info *dev_info)
189 unsigned long lowest_addr;
190 struct segment_info *entry;
194 list_for_each_entry(entry, &dev_info->seg_list, lh) {
195 if (set_first == 0) {
196 lowest_addr = entry->start;
199 if (lowest_addr > entry->start)
200 lowest_addr = entry->start;
207 * Check continuity of segments.
210 dcssblk_is_continuous(struct dcssblk_dev_info *dev_info)
213 struct segment_info *sort_list, *entry, temp;
215 if (dev_info->num_of_segments <= 1)
219 sizeof(struct segment_info) * dev_info->num_of_segments,
221 if (sort_list == NULL)
224 list_for_each_entry(entry, &dev_info->seg_list, lh) {
225 memcpy(&sort_list[i], entry, sizeof(struct segment_info));
230 for (i = 0; i < dev_info->num_of_segments; i++)
231 for (j = 0; j < dev_info->num_of_segments; j++)
232 if (sort_list[j].start > sort_list[i].start) {
233 memcpy(&temp, &sort_list[i],
234 sizeof(struct segment_info));
235 memcpy(&sort_list[i], &sort_list[j],
236 sizeof(struct segment_info));
237 memcpy(&sort_list[j], &temp,
238 sizeof(struct segment_info));
241 /* check continuity */
242 for (i = 0; i < dev_info->num_of_segments - 1; i++) {
243 if ((sort_list[i].end + 1) != sort_list[i+1].start) {
244 pr_err("Adjacent DCSSs %s and %s are not "
245 "contiguous\n", sort_list[i].segment_name,
246 sort_list[i+1].segment_name);
250 /* EN and EW are allowed in a block device */
251 if (sort_list[i].segment_type != sort_list[i+1].segment_type) {
252 if (!(sort_list[i].segment_type & SEGMENT_EXCLUSIVE) ||
253 (sort_list[i].segment_type == SEG_TYPE_ER) ||
254 !(sort_list[i+1].segment_type &
255 SEGMENT_EXCLUSIVE) ||
256 (sort_list[i+1].segment_type == SEG_TYPE_ER)) {
257 pr_err("DCSS %s and DCSS %s have "
258 "incompatible types\n",
259 sort_list[i].segment_name,
260 sort_list[i+1].segment_name);
276 dcssblk_load_segment(char *name, struct segment_info **seg_info)
280 /* already loaded? */
281 down_read(&dcssblk_devices_sem);
282 *seg_info = dcssblk_get_segment_by_name(name);
283 up_read(&dcssblk_devices_sem);
284 if (*seg_info != NULL)
287 /* get a struct segment_info */
288 *seg_info = kzalloc(sizeof(struct segment_info), GFP_KERNEL);
289 if (*seg_info == NULL)
292 strcpy((*seg_info)->segment_name, name);
294 /* load the segment */
295 rc = segment_load(name, SEGMENT_SHARED,
296 &(*seg_info)->start, &(*seg_info)->end);
298 segment_warning(rc, (*seg_info)->segment_name);
301 INIT_LIST_HEAD(&(*seg_info)->lh);
302 (*seg_info)->segment_type = rc;
308 * device attribute for switching shared/nonshared (exclusive)
309 * operation (show + store)
312 dcssblk_shared_show(struct device *dev, struct device_attribute *attr, char *buf)
314 struct dcssblk_dev_info *dev_info;
316 dev_info = container_of(dev, struct dcssblk_dev_info, dev);
317 return sprintf(buf, dev_info->is_shared ? "1\n" : "0\n");
321 dcssblk_shared_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count)
323 struct dcssblk_dev_info *dev_info;
324 struct segment_info *entry, *temp;
327 if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0'))
329 down_write(&dcssblk_devices_sem);
330 dev_info = container_of(dev, struct dcssblk_dev_info, dev);
331 if (atomic_read(&dev_info->use_count)) {
335 if (inbuf[0] == '1') {
336 /* reload segments in shared mode */
337 list_for_each_entry(entry, &dev_info->seg_list, lh) {
338 rc = segment_modify_shared(entry->segment_name,
341 BUG_ON(rc == -EINVAL);
346 dev_info->is_shared = 1;
347 switch (dev_info->segment_type) {
351 set_disk_ro(dev_info->gd, 1);
353 } else if (inbuf[0] == '0') {
354 /* reload segments in exclusive mode */
355 if (dev_info->segment_type == SEG_TYPE_SC) {
356 pr_err("DCSS %s is of type SC and cannot be "
357 "loaded as exclusive-writable\n",
358 dev_info->segment_name);
362 list_for_each_entry(entry, &dev_info->seg_list, lh) {
363 rc = segment_modify_shared(entry->segment_name,
366 BUG_ON(rc == -EINVAL);
371 dev_info->is_shared = 0;
372 set_disk_ro(dev_info->gd, 0);
381 pr_err("DCSS device %s is removed after a failed access mode "
382 "change\n", dev_info->segment_name);
384 list_for_each_entry(entry, &dev_info->seg_list, lh) {
386 segment_unload(entry->segment_name);
388 list_del(&dev_info->lh);
390 del_gendisk(dev_info->gd);
391 blk_cleanup_queue(dev_info->dcssblk_queue);
392 dev_info->gd->queue = NULL;
393 put_disk(dev_info->gd);
394 up_write(&dcssblk_devices_sem);
396 if (device_remove_file_self(dev, attr)) {
397 device_unregister(dev);
402 up_write(&dcssblk_devices_sem);
405 static DEVICE_ATTR(shared, S_IWUSR | S_IRUSR, dcssblk_shared_show,
406 dcssblk_shared_store);
409 * device attribute for save operation on current copy
410 * of the segment. If the segment is busy, saving will
411 * become pending until it gets released, which can be
412 * undone by storing a non-true value to this entry.
416 dcssblk_save_show(struct device *dev, struct device_attribute *attr, char *buf)
418 struct dcssblk_dev_info *dev_info;
420 dev_info = container_of(dev, struct dcssblk_dev_info, dev);
421 return sprintf(buf, dev_info->save_pending ? "1\n" : "0\n");
425 dcssblk_save_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count)
427 struct dcssblk_dev_info *dev_info;
428 struct segment_info *entry;
430 if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0'))
432 dev_info = container_of(dev, struct dcssblk_dev_info, dev);
434 down_write(&dcssblk_devices_sem);
435 if (inbuf[0] == '1') {
436 if (atomic_read(&dev_info->use_count) == 0) {
437 // device is idle => we save immediately
438 pr_info("All DCSSs that map to device %s are "
439 "saved\n", dev_info->segment_name);
440 list_for_each_entry(entry, &dev_info->seg_list, lh) {
441 if (entry->segment_type == SEG_TYPE_EN ||
442 entry->segment_type == SEG_TYPE_SN)
443 pr_warn("DCSS %s is of type SN or EN"
444 " and cannot be saved\n",
445 entry->segment_name);
447 segment_save(entry->segment_name);
450 // device is busy => we save it when it becomes
451 // idle in dcssblk_release
452 pr_info("Device %s is in use, its DCSSs will be "
453 "saved when it becomes idle\n",
454 dev_info->segment_name);
455 dev_info->save_pending = 1;
457 } else if (inbuf[0] == '0') {
458 if (dev_info->save_pending) {
459 // device is busy & the user wants to undo his save
461 dev_info->save_pending = 0;
462 pr_info("A pending save request for device %s "
463 "has been canceled\n",
464 dev_info->segment_name);
467 up_write(&dcssblk_devices_sem);
470 up_write(&dcssblk_devices_sem);
473 static DEVICE_ATTR(save, S_IWUSR | S_IRUSR, dcssblk_save_show,
477 * device attribute for showing all segments in a device
480 dcssblk_seglist_show(struct device *dev, struct device_attribute *attr,
485 struct dcssblk_dev_info *dev_info;
486 struct segment_info *entry;
488 down_read(&dcssblk_devices_sem);
489 dev_info = container_of(dev, struct dcssblk_dev_info, dev);
492 list_for_each_entry(entry, &dev_info->seg_list, lh) {
493 strcpy(&buf[i], entry->segment_name);
494 i += strlen(entry->segment_name);
498 up_read(&dcssblk_devices_sem);
501 static DEVICE_ATTR(seglist, S_IRUSR, dcssblk_seglist_show, NULL);
503 static struct attribute *dcssblk_dev_attrs[] = {
504 &dev_attr_shared.attr,
506 &dev_attr_seglist.attr,
509 static struct attribute_group dcssblk_dev_attr_group = {
510 .attrs = dcssblk_dev_attrs,
512 static const struct attribute_group *dcssblk_dev_attr_groups[] = {
513 &dcssblk_dev_attr_group,
518 * device attribute for adding devices
521 dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
523 int rc, i, j, num_of_segments;
524 struct dcssblk_dev_info *dev_info;
525 struct segment_info *seg_info, *temp;
527 unsigned long seg_byte_size;
531 if (dev != dcssblk_root_dev) {
535 if ((count < 1) || (buf[0] == '\0') || (buf[0] == '\n')) {
540 local_buf = kmalloc(count + 1, GFP_KERNEL);
541 if (local_buf == NULL) {
550 for (i = 0; (i < count && (buf[i] != '\0') && (buf[i] != '\n')); i++) {
551 for (j = i; (buf[j] != ':') &&
555 local_buf[j-i] = toupper(buf[j]);
557 local_buf[j-i] = '\0';
558 if (((j - i) == 0) || ((j - i) > 8)) {
563 rc = dcssblk_load_segment(local_buf, &seg_info);
567 * get a struct dcssblk_dev_info
569 if (num_of_segments == 0) {
570 dev_info = kzalloc(sizeof(struct dcssblk_dev_info),
572 if (dev_info == NULL) {
576 strcpy(dev_info->segment_name, local_buf);
577 dev_info->segment_type = seg_info->segment_type;
578 INIT_LIST_HEAD(&dev_info->seg_list);
580 list_add_tail(&seg_info->lh, &dev_info->seg_list);
584 if ((buf[j] == '\0') || (buf[j] == '\n'))
588 /* no trailing colon at the end of the input */
589 if ((i > 0) && (buf[i-1] == ':')) {
593 strlcpy(local_buf, buf, i + 1);
594 dev_info->num_of_segments = num_of_segments;
595 rc = dcssblk_is_continuous(dev_info);
599 dev_info->start = dcssblk_find_lowest_addr(dev_info);
600 dev_info->end = dcssblk_find_highest_addr(dev_info);
602 dev_set_name(&dev_info->dev, "%s", dev_info->segment_name);
603 dev_info->dev.release = dcssblk_release_segment;
604 dev_info->dev.groups = dcssblk_dev_attr_groups;
605 INIT_LIST_HEAD(&dev_info->lh);
606 dev_info->gd = alloc_disk(DCSSBLK_MINORS_PER_DISK);
607 if (dev_info->gd == NULL) {
611 dev_info->gd->major = dcssblk_major;
612 dev_info->gd->fops = &dcssblk_devops;
613 dev_info->dcssblk_queue = blk_alloc_queue(GFP_KERNEL);
614 dev_info->gd->queue = dev_info->dcssblk_queue;
615 dev_info->gd->private_data = dev_info;
616 dev_info->gd->driverfs_dev = &dev_info->dev;
617 blk_queue_make_request(dev_info->dcssblk_queue, dcssblk_make_request);
618 blk_queue_logical_block_size(dev_info->dcssblk_queue, 4096);
620 seg_byte_size = (dev_info->end - dev_info->start + 1);
621 set_capacity(dev_info->gd, seg_byte_size >> 9); // size in sectors
622 pr_info("Loaded %s with total size %lu bytes and capacity %lu "
623 "sectors\n", local_buf, seg_byte_size, seg_byte_size >> 9);
625 dev_info->save_pending = 0;
626 dev_info->is_shared = 1;
627 dev_info->dev.parent = dcssblk_root_dev;
630 *get minor, add to list
632 down_write(&dcssblk_devices_sem);
633 if (dcssblk_get_segment_by_name(local_buf)) {
637 rc = dcssblk_assign_free_minor(dev_info);
640 sprintf(dev_info->gd->disk_name, "dcssblk%d",
641 dev_info->gd->first_minor);
642 list_add_tail(&dev_info->lh, &dcssblk_devices);
644 if (!try_module_get(THIS_MODULE)) {
649 * register the device
651 rc = device_register(&dev_info->dev);
655 get_device(&dev_info->dev);
656 add_disk(dev_info->gd);
658 switch (dev_info->segment_type) {
662 set_disk_ro(dev_info->gd,1);
665 set_disk_ro(dev_info->gd,0);
668 up_write(&dcssblk_devices_sem);
673 list_del(&dev_info->lh);
674 blk_cleanup_queue(dev_info->dcssblk_queue);
675 dev_info->gd->queue = NULL;
676 put_disk(dev_info->gd);
677 list_for_each_entry(seg_info, &dev_info->seg_list, lh) {
678 segment_unload(seg_info->segment_name);
680 put_device(&dev_info->dev);
681 up_write(&dcssblk_devices_sem);
684 list_del(&dev_info->lh);
686 blk_cleanup_queue(dev_info->dcssblk_queue);
687 dev_info->gd->queue = NULL;
688 put_disk(dev_info->gd);
689 up_write(&dcssblk_devices_sem);
691 if (dev_info == NULL)
693 list_for_each_entry_safe(seg_info, temp, &dev_info->seg_list, lh) {
694 list_del(&seg_info->lh);
695 segment_unload(seg_info->segment_name);
706 * device attribute for removing devices
709 dcssblk_remove_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
711 struct dcssblk_dev_info *dev_info;
712 struct segment_info *entry;
716 if (dev != dcssblk_root_dev) {
719 local_buf = kmalloc(count + 1, GFP_KERNEL);
720 if (local_buf == NULL) {
726 for (i = 0; ((*(buf+i)!='\0') && (*(buf+i)!='\n') && i < count); i++) {
727 local_buf[i] = toupper(buf[i]);
730 if ((i == 0) || (i > 8)) {
735 down_write(&dcssblk_devices_sem);
736 dev_info = dcssblk_get_device_by_name(local_buf);
737 if (dev_info == NULL) {
738 up_write(&dcssblk_devices_sem);
739 pr_warning("Device %s cannot be removed because it is not a "
740 "known device\n", local_buf);
744 if (atomic_read(&dev_info->use_count) != 0) {
745 up_write(&dcssblk_devices_sem);
746 pr_warning("Device %s cannot be removed while it is in "
752 list_del(&dev_info->lh);
753 del_gendisk(dev_info->gd);
754 blk_cleanup_queue(dev_info->dcssblk_queue);
755 dev_info->gd->queue = NULL;
756 put_disk(dev_info->gd);
757 device_unregister(&dev_info->dev);
759 /* unload all related segments */
760 list_for_each_entry(entry, &dev_info->seg_list, lh)
761 segment_unload(entry->segment_name);
763 put_device(&dev_info->dev);
764 up_write(&dcssblk_devices_sem);
773 dcssblk_open(struct block_device *bdev, fmode_t mode)
775 struct dcssblk_dev_info *dev_info;
778 dev_info = bdev->bd_disk->private_data;
779 if (NULL == dev_info) {
783 atomic_inc(&dev_info->use_count);
784 bdev->bd_block_size = 4096;
791 dcssblk_release(struct gendisk *disk, fmode_t mode)
793 struct dcssblk_dev_info *dev_info = disk->private_data;
794 struct segment_info *entry;
800 down_write(&dcssblk_devices_sem);
801 if (atomic_dec_and_test(&dev_info->use_count)
802 && (dev_info->save_pending)) {
803 pr_info("Device %s has become idle and is being saved "
804 "now\n", dev_info->segment_name);
805 list_for_each_entry(entry, &dev_info->seg_list, lh) {
806 if (entry->segment_type == SEG_TYPE_EN ||
807 entry->segment_type == SEG_TYPE_SN)
808 pr_warn("DCSS %s is of type SN or EN and cannot"
809 " be saved\n", entry->segment_name);
811 segment_save(entry->segment_name);
813 dev_info->save_pending = 0;
815 up_write(&dcssblk_devices_sem);
819 dcssblk_make_request(struct request_queue *q, struct bio *bio)
821 struct dcssblk_dev_info *dev_info;
823 struct bvec_iter iter;
825 unsigned long page_addr;
826 unsigned long source_addr;
827 unsigned long bytes_done;
830 dev_info = bio->bi_bdev->bd_disk->private_data;
831 if (dev_info == NULL)
833 if ((bio->bi_iter.bi_sector & 7) != 0 ||
834 (bio->bi_iter.bi_size & 4095) != 0)
835 /* Request is not page-aligned. */
837 if (bio_end_sector(bio) > get_capacity(bio->bi_bdev->bd_disk)) {
838 /* Request beyond end of DCSS segment. */
841 /* verify data transfer direction */
842 if (dev_info->is_shared) {
843 switch (dev_info->segment_type) {
847 /* cannot write to these segments */
848 if (bio_data_dir(bio) == WRITE) {
849 pr_warning("Writing to %s failed because it "
850 "is a read-only device\n",
851 dev_name(&dev_info->dev));
857 index = (bio->bi_iter.bi_sector >> 3);
858 bio_for_each_segment(bvec, bio, iter) {
859 page_addr = (unsigned long)
860 page_address(bvec.bv_page) + bvec.bv_offset;
861 source_addr = dev_info->start + (index<<12) + bytes_done;
862 if (unlikely((page_addr & 4095) != 0) || (bvec.bv_len & 4095) != 0)
865 if (bio_data_dir(bio) == READ) {
866 memcpy((void*)page_addr, (void*)source_addr,
869 memcpy((void*)source_addr, (void*)page_addr,
872 bytes_done += bvec.bv_len;
881 dcssblk_direct_access (struct block_device *bdev, sector_t secnum,
882 void **kaddr, unsigned long *pfn, long size)
884 struct dcssblk_dev_info *dev_info;
885 unsigned long offset, dev_sz;
887 dev_info = bdev->bd_disk->private_data;
890 dev_sz = dev_info->end - dev_info->start;
891 offset = secnum * 512;
892 *kaddr = (void *) (dev_info->start + offset);
893 *pfn = virt_to_phys(*kaddr) >> PAGE_SHIFT;
895 return dev_sz - offset;
899 dcssblk_check_params(void)
902 char buf[DCSSBLK_PARM_LEN + 1];
903 struct dcssblk_dev_info *dev_info;
905 for (i = 0; (i < DCSSBLK_PARM_LEN) && (dcssblk_segments[i] != '\0');
907 for (j = i; (dcssblk_segments[j] != ',') &&
908 (dcssblk_segments[j] != '\0') &&
909 (dcssblk_segments[j] != '(') &&
910 (j < DCSSBLK_PARM_LEN); j++)
912 buf[j-i] = dcssblk_segments[j];
915 rc = dcssblk_add_store(dcssblk_root_dev, NULL, buf, j-i);
916 if ((rc >= 0) && (dcssblk_segments[j] == '(')) {
917 for (k = 0; (buf[k] != ':') && (buf[k] != '\0'); k++)
918 buf[k] = toupper(buf[k]);
920 if (!strncmp(&dcssblk_segments[j], "(local)", 7)) {
921 down_read(&dcssblk_devices_sem);
922 dev_info = dcssblk_get_device_by_name(buf);
923 up_read(&dcssblk_devices_sem);
925 dcssblk_shared_store(&dev_info->dev,
929 while ((dcssblk_segments[j] != ',') &&
930 (dcssblk_segments[j] != '\0'))
934 if (dcssblk_segments[j] == '\0')
943 static int dcssblk_freeze(struct device *dev)
945 struct dcssblk_dev_info *dev_info;
948 list_for_each_entry(dev_info, &dcssblk_devices, lh) {
949 switch (dev_info->segment_type) {
953 if (!dev_info->is_shared)
964 pr_err("Suspending the system failed because DCSS device %s "
966 dev_info->segment_name);
970 static int dcssblk_restore(struct device *dev)
972 struct dcssblk_dev_info *dev_info;
973 struct segment_info *entry;
974 unsigned long start, end;
977 list_for_each_entry(dev_info, &dcssblk_devices, lh) {
978 list_for_each_entry(entry, &dev_info->seg_list, lh) {
979 segment_unload(entry->segment_name);
980 rc = segment_load(entry->segment_name, SEGMENT_SHARED,
983 // TODO in_use check ?
984 segment_warning(rc, entry->segment_name);
987 if (start != entry->start || end != entry->end) {
988 pr_err("The address range of DCSS %s changed "
989 "while the system was suspended\n",
990 entry->segment_name);
997 panic("fatal dcssblk resume error\n");
1000 static int dcssblk_thaw(struct device *dev)
1005 static const struct dev_pm_ops dcssblk_pm_ops = {
1006 .freeze = dcssblk_freeze,
1007 .thaw = dcssblk_thaw,
1008 .restore = dcssblk_restore,
1011 static struct platform_driver dcssblk_pdrv = {
1014 .pm = &dcssblk_pm_ops,
1018 static struct platform_device *dcssblk_pdev;
1022 * The init/exit functions.
1027 platform_device_unregister(dcssblk_pdev);
1028 platform_driver_unregister(&dcssblk_pdrv);
1029 root_device_unregister(dcssblk_root_dev);
1030 unregister_blkdev(dcssblk_major, DCSSBLK_NAME);
1038 rc = platform_driver_register(&dcssblk_pdrv);
1042 dcssblk_pdev = platform_device_register_simple("dcssblk", -1, NULL,
1044 if (IS_ERR(dcssblk_pdev)) {
1045 rc = PTR_ERR(dcssblk_pdev);
1049 dcssblk_root_dev = root_device_register("dcssblk");
1050 if (IS_ERR(dcssblk_root_dev)) {
1051 rc = PTR_ERR(dcssblk_root_dev);
1054 rc = device_create_file(dcssblk_root_dev, &dev_attr_add);
1057 rc = device_create_file(dcssblk_root_dev, &dev_attr_remove);
1060 rc = register_blkdev(0, DCSSBLK_NAME);
1064 init_rwsem(&dcssblk_devices_sem);
1066 dcssblk_check_params();
1070 root_device_unregister(dcssblk_root_dev);
1072 platform_device_unregister(dcssblk_pdev);
1074 platform_driver_unregister(&dcssblk_pdrv);
1078 module_init(dcssblk_init);
1079 module_exit(dcssblk_exit);
1081 module_param_string(segments, dcssblk_segments, DCSSBLK_PARM_LEN, 0444);
1082 MODULE_PARM_DESC(segments, "Name of DCSS segment(s) to be loaded, "
1083 "comma-separated list, names in each set separated "
1084 "by commas are separated by colons, each set contains "
1085 "names of contiguous segments and each name max. 8 chars.\n"
1086 "Adding \"(local)\" to the end of each set equals echoing 0 "
1087 "to /sys/devices/dcssblk/<device name>/shared after loading "
1088 "the contiguous segments - \n"
1089 "e.g. segments=\"mydcss1,mydcss2:mydcss3,mydcss4(local)\"");
1091 MODULE_LICENSE("GPL");