| /* |
| * dcssblk.c -- the S/390 block driver for dcss memory |
| * |
| * Authors: Carsten Otte, Stefan Weinhuber, Gerald Schaefer |
| */ |
| |
| #define KMSG_COMPONENT "dcssblk" |
| #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt |
| |
| #include <linux/module.h> |
| #include <linux/moduleparam.h> |
| #include <linux/ctype.h> |
| #include <linux/errno.h> |
| #include <linux/init.h> |
| #include <linux/slab.h> |
| #include <linux/blkdev.h> |
| #include <linux/completion.h> |
| #include <linux/interrupt.h> |
| #include <linux/platform_device.h> |
| #include <asm/extmem.h> |
| #include <asm/io.h> |
| |
| #define DCSSBLK_NAME "dcssblk" |
| #define DCSSBLK_MINORS_PER_DISK 1 |
| #define DCSSBLK_PARM_LEN 400 |
| #define DCSS_BUS_ID_SIZE 20 |
| |
| static int dcssblk_open(struct block_device *bdev, fmode_t mode); |
| static void dcssblk_release(struct gendisk *disk, fmode_t mode); |
| static void dcssblk_make_request(struct request_queue *q, struct bio *bio); |
| static long dcssblk_direct_access(struct block_device *bdev, sector_t secnum, |
| void **kaddr, unsigned long *pfn, long size); |
| |
| static char dcssblk_segments[DCSSBLK_PARM_LEN] = "\0"; |
| |
| static int dcssblk_major; |
| static const struct block_device_operations dcssblk_devops = { |
| .owner = THIS_MODULE, |
| .open = dcssblk_open, |
| .release = dcssblk_release, |
| .direct_access = dcssblk_direct_access, |
| }; |
| |
| struct dcssblk_dev_info { |
| struct list_head lh; |
| struct device dev; |
| char segment_name[DCSS_BUS_ID_SIZE]; |
| atomic_t use_count; |
| struct gendisk *gd; |
| unsigned long start; |
| unsigned long end; |
| int segment_type; |
| unsigned char save_pending; |
| unsigned char is_shared; |
| struct request_queue *dcssblk_queue; |
| int num_of_segments; |
| struct list_head seg_list; |
| }; |
| |
| struct segment_info { |
| struct list_head lh; |
| char segment_name[DCSS_BUS_ID_SIZE]; |
| unsigned long start; |
| unsigned long end; |
| int segment_type; |
| }; |
| |
| static ssize_t dcssblk_add_store(struct device * dev, struct device_attribute *attr, const char * buf, |
| size_t count); |
| static ssize_t dcssblk_remove_store(struct device * dev, struct device_attribute *attr, const char * buf, |
| size_t count); |
| |
| static DEVICE_ATTR(add, S_IWUSR, NULL, dcssblk_add_store); |
| static DEVICE_ATTR(remove, S_IWUSR, NULL, dcssblk_remove_store); |
| |
| static struct device *dcssblk_root_dev; |
| |
| static LIST_HEAD(dcssblk_devices); |
| static struct rw_semaphore dcssblk_devices_sem; |
| |
| /* |
| * release function for segment device. |
| */ |
| static void |
| dcssblk_release_segment(struct device *dev) |
| { |
| struct dcssblk_dev_info *dev_info; |
| struct segment_info *entry, *temp; |
| |
| dev_info = container_of(dev, struct dcssblk_dev_info, dev); |
| list_for_each_entry_safe(entry, temp, &dev_info->seg_list, lh) { |
| list_del(&entry->lh); |
| kfree(entry); |
| } |
| kfree(dev_info); |
| module_put(THIS_MODULE); |
| } |
| |
| /* |
| * get a minor number. needs to be called with |
| * down_write(&dcssblk_devices_sem) and the |
| * device needs to be enqueued before the semaphore is |
| * freed. |
| */ |
| static int |
| dcssblk_assign_free_minor(struct dcssblk_dev_info *dev_info) |
| { |
| int minor, found; |
| struct dcssblk_dev_info *entry; |
| |
| if (dev_info == NULL) |
| return -EINVAL; |
| for (minor = 0; minor < (1<<MINORBITS); minor++) { |
| found = 0; |
| // test if minor available |
| list_for_each_entry(entry, &dcssblk_devices, lh) |
| if (minor == entry->gd->first_minor) |
| found++; |
| if (!found) break; // got unused minor |
| } |
| if (found) |
| return -EBUSY; |
| dev_info->gd->first_minor = minor; |
| return 0; |
| } |
| |
| /* |
| * get the struct dcssblk_dev_info from dcssblk_devices |
| * for the given name. |
| * down_read(&dcssblk_devices_sem) must be held. |
| */ |
| static struct dcssblk_dev_info * |
| dcssblk_get_device_by_name(char *name) |
| { |
| struct dcssblk_dev_info *entry; |
| |
| list_for_each_entry(entry, &dcssblk_devices, lh) { |
| if (!strcmp(name, entry->segment_name)) { |
| return entry; |
| } |
| } |
| return NULL; |
| } |
| |
| /* |
| * get the struct segment_info from seg_list |
| * for the given name. |
| * down_read(&dcssblk_devices_sem) must be held. |
| */ |
| static struct segment_info * |
| dcssblk_get_segment_by_name(char *name) |
| { |
| struct dcssblk_dev_info *dev_info; |
| struct segment_info *entry; |
| |
| list_for_each_entry(dev_info, &dcssblk_devices, lh) { |
| list_for_each_entry(entry, &dev_info->seg_list, lh) { |
| if (!strcmp(name, entry->segment_name)) |
| return entry; |
| } |
| } |
| return NULL; |
| } |
| |
| /* |
| * get the highest address of the multi-segment block. |
| */ |
| static unsigned long |
| dcssblk_find_highest_addr(struct dcssblk_dev_info *dev_info) |
| { |
| unsigned long highest_addr; |
| struct segment_info *entry; |
| |
| highest_addr = 0; |
| list_for_each_entry(entry, &dev_info->seg_list, lh) { |
| if (highest_addr < entry->end) |
| highest_addr = entry->end; |
| } |
| return highest_addr; |
| } |
| |
| /* |
| * get the lowest address of the multi-segment block. |
| */ |
| static unsigned long |
| dcssblk_find_lowest_addr(struct dcssblk_dev_info *dev_info) |
| { |
| int set_first; |
| unsigned long lowest_addr; |
| struct segment_info *entry; |
| |
| set_first = 0; |
| lowest_addr = 0; |
| list_for_each_entry(entry, &dev_info->seg_list, lh) { |
| if (set_first == 0) { |
| lowest_addr = entry->start; |
| set_first = 1; |
| } else { |
| if (lowest_addr > entry->start) |
| lowest_addr = entry->start; |
| } |
| } |
| return lowest_addr; |
| } |
| |
| /* |
| * Check continuity of segments. |
| */ |
| static int |
| dcssblk_is_continuous(struct dcssblk_dev_info *dev_info) |
| { |
| int i, j, rc; |
| struct segment_info *sort_list, *entry, temp; |
| |
| if (dev_info->num_of_segments <= 1) |
| return 0; |
| |
| sort_list = kzalloc( |
| sizeof(struct segment_info) * dev_info->num_of_segments, |
| GFP_KERNEL); |
| if (sort_list == NULL) |
| return -ENOMEM; |
| i = 0; |
| list_for_each_entry(entry, &dev_info->seg_list, lh) { |
| memcpy(&sort_list[i], entry, sizeof(struct segment_info)); |
| i++; |
| } |
| |
| /* sort segments */ |
| for (i = 0; i < dev_info->num_of_segments; i++) |
| for (j = 0; j < dev_info->num_of_segments; j++) |
| if (sort_list[j].start > sort_list[i].start) { |
| memcpy(&temp, &sort_list[i], |
| sizeof(struct segment_info)); |
| memcpy(&sort_list[i], &sort_list[j], |
| sizeof(struct segment_info)); |
| memcpy(&sort_list[j], &temp, |
| sizeof(struct segment_info)); |
| } |
| |
| /* check continuity */ |
| for (i = 0; i < dev_info->num_of_segments - 1; i++) { |
| if ((sort_list[i].end + 1) != sort_list[i+1].start) { |
| pr_err("Adjacent DCSSs %s and %s are not " |
| "contiguous\n", sort_list[i].segment_name, |
| sort_list[i+1].segment_name); |
| rc = -EINVAL; |
| goto out; |
| } |
| /* EN and EW are allowed in a block device */ |
| if (sort_list[i].segment_type != sort_list[i+1].segment_type) { |
| if (!(sort_list[i].segment_type & SEGMENT_EXCLUSIVE) || |
| (sort_list[i].segment_type == SEG_TYPE_ER) || |
| !(sort_list[i+1].segment_type & |
| SEGMENT_EXCLUSIVE) || |
| (sort_list[i+1].segment_type == SEG_TYPE_ER)) { |
| pr_err("DCSS %s and DCSS %s have " |
| "incompatible types\n", |
| sort_list[i].segment_name, |
| sort_list[i+1].segment_name); |
| rc = -EINVAL; |
| goto out; |
| } |
| } |
| } |
| rc = 0; |
| out: |
| kfree(sort_list); |
| return rc; |
| } |
| |
| /* |
| * Load a segment |
| */ |
| static int |
| dcssblk_load_segment(char *name, struct segment_info **seg_info) |
| { |
| int rc; |
| |
| /* already loaded? */ |
| down_read(&dcssblk_devices_sem); |
| *seg_info = dcssblk_get_segment_by_name(name); |
| up_read(&dcssblk_devices_sem); |
| if (*seg_info != NULL) |
| return -EEXIST; |
| |
| /* get a struct segment_info */ |
| *seg_info = kzalloc(sizeof(struct segment_info), GFP_KERNEL); |
| if (*seg_info == NULL) |
| return -ENOMEM; |
| |
| strcpy((*seg_info)->segment_name, name); |
| |
| /* load the segment */ |
| rc = segment_load(name, SEGMENT_SHARED, |
| &(*seg_info)->start, &(*seg_info)->end); |
| if (rc < 0) { |
| segment_warning(rc, (*seg_info)->segment_name); |
| kfree(*seg_info); |
| } else { |
| INIT_LIST_HEAD(&(*seg_info)->lh); |
| (*seg_info)->segment_type = rc; |
| } |
| return rc; |
| } |
| |
| /* |
| * device attribute for switching shared/nonshared (exclusive) |
| * operation (show + store) |
| */ |
| static ssize_t |
| dcssblk_shared_show(struct device *dev, struct device_attribute *attr, char *buf) |
| { |
| struct dcssblk_dev_info *dev_info; |
| |
| dev_info = container_of(dev, struct dcssblk_dev_info, dev); |
| return sprintf(buf, dev_info->is_shared ? "1\n" : "0\n"); |
| } |
| |
| static ssize_t |
| dcssblk_shared_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count) |
| { |
| struct dcssblk_dev_info *dev_info; |
| struct segment_info *entry, *temp; |
| int rc; |
| |
| if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0')) |
| return -EINVAL; |
| down_write(&dcssblk_devices_sem); |
| dev_info = container_of(dev, struct dcssblk_dev_info, dev); |
| if (atomic_read(&dev_info->use_count)) { |
| rc = -EBUSY; |
| goto out; |
| } |
| if (inbuf[0] == '1') { |
| /* reload segments in shared mode */ |
| list_for_each_entry(entry, &dev_info->seg_list, lh) { |
| rc = segment_modify_shared(entry->segment_name, |
| SEGMENT_SHARED); |
| if (rc < 0) { |
| BUG_ON(rc == -EINVAL); |
| if (rc != -EAGAIN) |
| goto removeseg; |
| } |
| } |
| dev_info->is_shared = 1; |
| switch (dev_info->segment_type) { |
| case SEG_TYPE_SR: |
| case SEG_TYPE_ER: |
| case SEG_TYPE_SC: |
| set_disk_ro(dev_info->gd, 1); |
| } |
| } else if (inbuf[0] == '0') { |
| /* reload segments in exclusive mode */ |
| if (dev_info->segment_type == SEG_TYPE_SC) { |
| pr_err("DCSS %s is of type SC and cannot be " |
| "loaded as exclusive-writable\n", |
| dev_info->segment_name); |
| rc = -EINVAL; |
| goto out; |
| } |
| list_for_each_entry(entry, &dev_info->seg_list, lh) { |
| rc = segment_modify_shared(entry->segment_name, |
| SEGMENT_EXCLUSIVE); |
| if (rc < 0) { |
| BUG_ON(rc == -EINVAL); |
| if (rc != -EAGAIN) |
| goto removeseg; |
| } |
| } |
| dev_info->is_shared = 0; |
| set_disk_ro(dev_info->gd, 0); |
| } else { |
| rc = -EINVAL; |
| goto out; |
| } |
| rc = count; |
| goto out; |
| |
| removeseg: |
| pr_err("DCSS device %s is removed after a failed access mode " |
| "change\n", dev_info->segment_name); |
| temp = entry; |
| list_for_each_entry(entry, &dev_info->seg_list, lh) { |
| if (entry != temp) |
| segment_unload(entry->segment_name); |
| } |
| list_del(&dev_info->lh); |
| |
| del_gendisk(dev_info->gd); |
| blk_cleanup_queue(dev_info->dcssblk_queue); |
| dev_info->gd->queue = NULL; |
| put_disk(dev_info->gd); |
| up_write(&dcssblk_devices_sem); |
| |
| if (device_remove_file_self(dev, attr)) { |
| device_unregister(dev); |
| put_device(dev); |
| } |
| return rc; |
| out: |
| up_write(&dcssblk_devices_sem); |
| return rc; |
| } |
| static DEVICE_ATTR(shared, S_IWUSR | S_IRUSR, dcssblk_shared_show, |
| dcssblk_shared_store); |
| |
| /* |
| * device attribute for save operation on current copy |
| * of the segment. If the segment is busy, saving will |
| * become pending until it gets released, which can be |
| * undone by storing a non-true value to this entry. |
| * (show + store) |
| */ |
| static ssize_t |
| dcssblk_save_show(struct device *dev, struct device_attribute *attr, char *buf) |
| { |
| struct dcssblk_dev_info *dev_info; |
| |
| dev_info = container_of(dev, struct dcssblk_dev_info, dev); |
| return sprintf(buf, dev_info->save_pending ? "1\n" : "0\n"); |
| } |
| |
| static ssize_t |
| dcssblk_save_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count) |
| { |
| struct dcssblk_dev_info *dev_info; |
| struct segment_info *entry; |
| |
| if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0')) |
| return -EINVAL; |
| dev_info = container_of(dev, struct dcssblk_dev_info, dev); |
| |
| down_write(&dcssblk_devices_sem); |
| if (inbuf[0] == '1') { |
| if (atomic_read(&dev_info->use_count) == 0) { |
| // device is idle => we save immediately |
| pr_info("All DCSSs that map to device %s are " |
| "saved\n", dev_info->segment_name); |
| list_for_each_entry(entry, &dev_info->seg_list, lh) { |
| if (entry->segment_type == SEG_TYPE_EN || |
| entry->segment_type == SEG_TYPE_SN) |
| pr_warn("DCSS %s is of type SN or EN" |
| " and cannot be saved\n", |
| entry->segment_name); |
| else |
| segment_save(entry->segment_name); |
| } |
| } else { |
| // device is busy => we save it when it becomes |
| // idle in dcssblk_release |
| pr_info("Device %s is in use, its DCSSs will be " |
| "saved when it becomes idle\n", |
| dev_info->segment_name); |
| dev_info->save_pending = 1; |
| } |
| } else if (inbuf[0] == '0') { |
| if (dev_info->save_pending) { |
| // device is busy & the user wants to undo his save |
| // request |
| dev_info->save_pending = 0; |
| pr_info("A pending save request for device %s " |
| "has been canceled\n", |
| dev_info->segment_name); |
| } |
| } else { |
| up_write(&dcssblk_devices_sem); |
| return -EINVAL; |
| } |
| up_write(&dcssblk_devices_sem); |
| return count; |
| } |
| static DEVICE_ATTR(save, S_IWUSR | S_IRUSR, dcssblk_save_show, |
| dcssblk_save_store); |
| |
| /* |
| * device attribute for showing all segments in a device |
| */ |
| static ssize_t |
| dcssblk_seglist_show(struct device *dev, struct device_attribute *attr, |
| char *buf) |
| { |
| int i; |
| |
| struct dcssblk_dev_info *dev_info; |
| struct segment_info *entry; |
| |
| down_read(&dcssblk_devices_sem); |
| dev_info = container_of(dev, struct dcssblk_dev_info, dev); |
| i = 0; |
| buf[0] = '\0'; |
| list_for_each_entry(entry, &dev_info->seg_list, lh) { |
| strcpy(&buf[i], entry->segment_name); |
| i += strlen(entry->segment_name); |
| buf[i] = '\n'; |
| i++; |
| } |
| up_read(&dcssblk_devices_sem); |
| return i; |
| } |
| static DEVICE_ATTR(seglist, S_IRUSR, dcssblk_seglist_show, NULL); |
| |
| static struct attribute *dcssblk_dev_attrs[] = { |
| &dev_attr_shared.attr, |
| &dev_attr_save.attr, |
| &dev_attr_seglist.attr, |
| NULL, |
| }; |
| static struct attribute_group dcssblk_dev_attr_group = { |
| .attrs = dcssblk_dev_attrs, |
| }; |
| static const struct attribute_group *dcssblk_dev_attr_groups[] = { |
| &dcssblk_dev_attr_group, |
| NULL, |
| }; |
| |
| /* |
| * device attribute for adding devices |
| */ |
| static ssize_t |
| dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
| { |
| int rc, i, j, num_of_segments; |
| struct dcssblk_dev_info *dev_info; |
| struct segment_info *seg_info, *temp; |
| char *local_buf; |
| unsigned long seg_byte_size; |
| |
| dev_info = NULL; |
| seg_info = NULL; |
| if (dev != dcssblk_root_dev) { |
| rc = -EINVAL; |
| goto out_nobuf; |
| } |
| if ((count < 1) || (buf[0] == '\0') || (buf[0] == '\n')) { |
| rc = -ENAMETOOLONG; |
| goto out_nobuf; |
| } |
| |
| local_buf = kmalloc(count + 1, GFP_KERNEL); |
| if (local_buf == NULL) { |
| rc = -ENOMEM; |
| goto out_nobuf; |
| } |
| |
| /* |
| * parse input |
| */ |
| num_of_segments = 0; |
| for (i = 0; (i < count && (buf[i] != '\0') && (buf[i] != '\n')); i++) { |
| for (j = i; j < count && |
| (buf[j] != ':') && |
| (buf[j] != '\0') && |
| (buf[j] != '\n'); j++) { |
| local_buf[j-i] = toupper(buf[j]); |
| } |
| local_buf[j-i] = '\0'; |
| if (((j - i) == 0) || ((j - i) > 8)) { |
| rc = -ENAMETOOLONG; |
| goto seg_list_del; |
| } |
| |
| rc = dcssblk_load_segment(local_buf, &seg_info); |
| if (rc < 0) |
| goto seg_list_del; |
| /* |
| * get a struct dcssblk_dev_info |
| */ |
| if (num_of_segments == 0) { |
| dev_info = kzalloc(sizeof(struct dcssblk_dev_info), |
| GFP_KERNEL); |
| if (dev_info == NULL) { |
| rc = -ENOMEM; |
| goto out; |
| } |
| strcpy(dev_info->segment_name, local_buf); |
| dev_info->segment_type = seg_info->segment_type; |
| INIT_LIST_HEAD(&dev_info->seg_list); |
| } |
| list_add_tail(&seg_info->lh, &dev_info->seg_list); |
| num_of_segments++; |
| i = j; |
| |
| if ((buf[j] == '\0') || (buf[j] == '\n')) |
| break; |
| } |
| |
| /* no trailing colon at the end of the input */ |
| if ((i > 0) && (buf[i-1] == ':')) { |
| rc = -ENAMETOOLONG; |
| goto seg_list_del; |
| } |
| strlcpy(local_buf, buf, i + 1); |
| dev_info->num_of_segments = num_of_segments; |
| rc = dcssblk_is_continuous(dev_info); |
| if (rc < 0) |
| goto seg_list_del; |
| |
| dev_info->start = dcssblk_find_lowest_addr(dev_info); |
| dev_info->end = dcssblk_find_highest_addr(dev_info); |
| |
| dev_set_name(&dev_info->dev, "%s", dev_info->segment_name); |
| dev_info->dev.release = dcssblk_release_segment; |
| dev_info->dev.groups = dcssblk_dev_attr_groups; |
| INIT_LIST_HEAD(&dev_info->lh); |
| dev_info->gd = alloc_disk(DCSSBLK_MINORS_PER_DISK); |
| if (dev_info->gd == NULL) { |
| rc = -ENOMEM; |
| goto seg_list_del; |
| } |
| dev_info->gd->major = dcssblk_major; |
| dev_info->gd->fops = &dcssblk_devops; |
| dev_info->dcssblk_queue = blk_alloc_queue(GFP_KERNEL); |
| dev_info->gd->queue = dev_info->dcssblk_queue; |
| dev_info->gd->private_data = dev_info; |
| dev_info->gd->driverfs_dev = &dev_info->dev; |
| blk_queue_make_request(dev_info->dcssblk_queue, dcssblk_make_request); |
| blk_queue_logical_block_size(dev_info->dcssblk_queue, 4096); |
| |
| seg_byte_size = (dev_info->end - dev_info->start + 1); |
| set_capacity(dev_info->gd, seg_byte_size >> 9); // size in sectors |
| pr_info("Loaded %s with total size %lu bytes and capacity %lu " |
| "sectors\n", local_buf, seg_byte_size, seg_byte_size >> 9); |
| |
| dev_info->save_pending = 0; |
| dev_info->is_shared = 1; |
| dev_info->dev.parent = dcssblk_root_dev; |
| |
| /* |
| *get minor, add to list |
| */ |
| down_write(&dcssblk_devices_sem); |
| if (dcssblk_get_segment_by_name(local_buf)) { |
| rc = -EEXIST; |
| goto release_gd; |
| } |
| rc = dcssblk_assign_free_minor(dev_info); |
| if (rc) |
| goto release_gd; |
| sprintf(dev_info->gd->disk_name, "dcssblk%d", |
| dev_info->gd->first_minor); |
| list_add_tail(&dev_info->lh, &dcssblk_devices); |
| |
| if (!try_module_get(THIS_MODULE)) { |
| rc = -ENODEV; |
| goto dev_list_del; |
| } |
| /* |
| * register the device |
| */ |
| rc = device_register(&dev_info->dev); |
| if (rc) |
| goto put_dev; |
| |
| get_device(&dev_info->dev); |
| add_disk(dev_info->gd); |
| |
| switch (dev_info->segment_type) { |
| case SEG_TYPE_SR: |
| case SEG_TYPE_ER: |
| case SEG_TYPE_SC: |
| set_disk_ro(dev_info->gd,1); |
| break; |
| default: |
| set_disk_ro(dev_info->gd,0); |
| break; |
| } |
| up_write(&dcssblk_devices_sem); |
| rc = count; |
| goto out; |
| |
| put_dev: |
| list_del(&dev_info->lh); |
| blk_cleanup_queue(dev_info->dcssblk_queue); |
| dev_info->gd->queue = NULL; |
| put_disk(dev_info->gd); |
| list_for_each_entry(seg_info, &dev_info->seg_list, lh) { |
| segment_unload(seg_info->segment_name); |
| } |
| put_device(&dev_info->dev); |
| up_write(&dcssblk_devices_sem); |
| goto out; |
| dev_list_del: |
| list_del(&dev_info->lh); |
| release_gd: |
| blk_cleanup_queue(dev_info->dcssblk_queue); |
| dev_info->gd->queue = NULL; |
| put_disk(dev_info->gd); |
| up_write(&dcssblk_devices_sem); |
| seg_list_del: |
| if (dev_info == NULL) |
| goto out; |
| list_for_each_entry_safe(seg_info, temp, &dev_info->seg_list, lh) { |
| list_del(&seg_info->lh); |
| segment_unload(seg_info->segment_name); |
| kfree(seg_info); |
| } |
| kfree(dev_info); |
| out: |
| kfree(local_buf); |
| out_nobuf: |
| return rc; |
| } |
| |
| /* |
| * device attribute for removing devices |
| */ |
| static ssize_t |
| dcssblk_remove_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
| { |
| struct dcssblk_dev_info *dev_info; |
| struct segment_info *entry; |
| int rc, i; |
| char *local_buf; |
| |
| if (dev != dcssblk_root_dev) { |
| return -EINVAL; |
| } |
| local_buf = kmalloc(count + 1, GFP_KERNEL); |
| if (local_buf == NULL) { |
| return -ENOMEM; |
| } |
| /* |
| * parse input |
| */ |
| for (i = 0; (i < count && (*(buf+i)!='\0') && (*(buf+i)!='\n')); i++) { |
| local_buf[i] = toupper(buf[i]); |
| } |
| local_buf[i] = '\0'; |
| if ((i == 0) || (i > 8)) { |
| rc = -ENAMETOOLONG; |
| goto out_buf; |
| } |
| |
| down_write(&dcssblk_devices_sem); |
| dev_info = dcssblk_get_device_by_name(local_buf); |
| if (dev_info == NULL) { |
| up_write(&dcssblk_devices_sem); |
| pr_warning("Device %s cannot be removed because it is not a " |
| "known device\n", local_buf); |
| rc = -ENODEV; |
| goto out_buf; |
| } |
| if (atomic_read(&dev_info->use_count) != 0) { |
| up_write(&dcssblk_devices_sem); |
| pr_warning("Device %s cannot be removed while it is in " |
| "use\n", local_buf); |
| rc = -EBUSY; |
| goto out_buf; |
| } |
| |
| list_del(&dev_info->lh); |
| del_gendisk(dev_info->gd); |
| blk_cleanup_queue(dev_info->dcssblk_queue); |
| dev_info->gd->queue = NULL; |
| put_disk(dev_info->gd); |
| device_unregister(&dev_info->dev); |
| |
| /* unload all related segments */ |
| list_for_each_entry(entry, &dev_info->seg_list, lh) |
| segment_unload(entry->segment_name); |
| |
| put_device(&dev_info->dev); |
| up_write(&dcssblk_devices_sem); |
| |
| rc = count; |
| out_buf: |
| kfree(local_buf); |
| return rc; |
| } |
| |
| static int |
| dcssblk_open(struct block_device *bdev, fmode_t mode) |
| { |
| struct dcssblk_dev_info *dev_info; |
| int rc; |
| |
| dev_info = bdev->bd_disk->private_data; |
| if (NULL == dev_info) { |
| rc = -ENODEV; |
| goto out; |
| } |
| atomic_inc(&dev_info->use_count); |
| bdev->bd_block_size = 4096; |
| rc = 0; |
| out: |
| return rc; |
| } |
| |
| static void |
| dcssblk_release(struct gendisk *disk, fmode_t mode) |
| { |
| struct dcssblk_dev_info *dev_info = disk->private_data; |
| struct segment_info *entry; |
| |
| if (!dev_info) { |
| WARN_ON(1); |
| return; |
| } |
| down_write(&dcssblk_devices_sem); |
| if (atomic_dec_and_test(&dev_info->use_count) |
| && (dev_info->save_pending)) { |
| pr_info("Device %s has become idle and is being saved " |
| "now\n", dev_info->segment_name); |
| list_for_each_entry(entry, &dev_info->seg_list, lh) { |
| if (entry->segment_type == SEG_TYPE_EN || |
| entry->segment_type == SEG_TYPE_SN) |
| pr_warn("DCSS %s is of type SN or EN and cannot" |
| " be saved\n", entry->segment_name); |
| else |
| segment_save(entry->segment_name); |
| } |
| dev_info->save_pending = 0; |
| } |
| up_write(&dcssblk_devices_sem); |
| } |
| |
| static void |
| dcssblk_make_request(struct request_queue *q, struct bio *bio) |
| { |
| struct dcssblk_dev_info *dev_info; |
| struct bio_vec bvec; |
| struct bvec_iter iter; |
| unsigned long index; |
| unsigned long page_addr; |
| unsigned long source_addr; |
| unsigned long bytes_done; |
| |
| blk_queue_split(q, &bio, q->bio_split); |
| |
| bytes_done = 0; |
| dev_info = bio->bi_bdev->bd_disk->private_data; |
| if (dev_info == NULL) |
| goto fail; |
| if ((bio->bi_iter.bi_sector & 7) != 0 || |
| (bio->bi_iter.bi_size & 4095) != 0) |
| /* Request is not page-aligned. */ |
| goto fail; |
| if (bio_end_sector(bio) > get_capacity(bio->bi_bdev->bd_disk)) { |
| /* Request beyond end of DCSS segment. */ |
| goto fail; |
| } |
| /* verify data transfer direction */ |
| if (dev_info->is_shared) { |
| switch (dev_info->segment_type) { |
| case SEG_TYPE_SR: |
| case SEG_TYPE_ER: |
| case SEG_TYPE_SC: |
| /* cannot write to these segments */ |
| if (bio_data_dir(bio) == WRITE) { |
| pr_warning("Writing to %s failed because it " |
| "is a read-only device\n", |
| dev_name(&dev_info->dev)); |
| goto fail; |
| } |
| } |
| } |
| |
| index = (bio->bi_iter.bi_sector >> 3); |
| bio_for_each_segment(bvec, bio, iter) { |
| page_addr = (unsigned long) |
| page_address(bvec.bv_page) + bvec.bv_offset; |
| source_addr = dev_info->start + (index<<12) + bytes_done; |
| if (unlikely((page_addr & 4095) != 0) || (bvec.bv_len & 4095) != 0) |
| // More paranoia. |
| goto fail; |
| if (bio_data_dir(bio) == READ) { |
| memcpy((void*)page_addr, (void*)source_addr, |
| bvec.bv_len); |
| } else { |
| memcpy((void*)source_addr, (void*)page_addr, |
| bvec.bv_len); |
| } |
| bytes_done += bvec.bv_len; |
| } |
| bio_endio(bio); |
| return; |
| fail: |
| bio_io_error(bio); |
| } |
| |
| static long |
| dcssblk_direct_access (struct block_device *bdev, sector_t secnum, |
| void **kaddr, unsigned long *pfn, long size) |
| { |
| struct dcssblk_dev_info *dev_info; |
| unsigned long offset, dev_sz; |
| |
| dev_info = bdev->bd_disk->private_data; |
| if (!dev_info) |
| return -ENODEV; |
| dev_sz = dev_info->end - dev_info->start; |
| offset = secnum * 512; |
| *kaddr = (void *) (dev_info->start + offset); |
| *pfn = virt_to_phys(*kaddr) >> PAGE_SHIFT; |
| |
| return dev_sz - offset; |
| } |
| |
| static void |
| dcssblk_check_params(void) |
| { |
| int rc, i, j, k; |
| char buf[DCSSBLK_PARM_LEN + 1]; |
| struct dcssblk_dev_info *dev_info; |
| |
| for (i = 0; (i < DCSSBLK_PARM_LEN) && (dcssblk_segments[i] != '\0'); |
| i++) { |
| for (j = i; (j < DCSSBLK_PARM_LEN) && |
| (dcssblk_segments[j] != ',') && |
| (dcssblk_segments[j] != '\0') && |
| (dcssblk_segments[j] != '('); j++) |
| { |
| buf[j-i] = dcssblk_segments[j]; |
| } |
| buf[j-i] = '\0'; |
| rc = dcssblk_add_store(dcssblk_root_dev, NULL, buf, j-i); |
| if ((rc >= 0) && (dcssblk_segments[j] == '(')) { |
| for (k = 0; (buf[k] != ':') && (buf[k] != '\0'); k++) |
| buf[k] = toupper(buf[k]); |
| buf[k] = '\0'; |
| if (!strncmp(&dcssblk_segments[j], "(local)", 7)) { |
| down_read(&dcssblk_devices_sem); |
| dev_info = dcssblk_get_device_by_name(buf); |
| up_read(&dcssblk_devices_sem); |
| if (dev_info) |
| dcssblk_shared_store(&dev_info->dev, |
| NULL, "0\n", 2); |
| } |
| } |
| while ((dcssblk_segments[j] != ',') && |
| (dcssblk_segments[j] != '\0')) |
| { |
| j++; |
| } |
| if (dcssblk_segments[j] == '\0') |
| break; |
| i = j; |
| } |
| } |
| |
| /* |
| * Suspend / Resume |
| */ |
| static int dcssblk_freeze(struct device *dev) |
| { |
| struct dcssblk_dev_info *dev_info; |
| int rc = 0; |
| |
| list_for_each_entry(dev_info, &dcssblk_devices, lh) { |
| switch (dev_info->segment_type) { |
| case SEG_TYPE_SR: |
| case SEG_TYPE_ER: |
| case SEG_TYPE_SC: |
| if (!dev_info->is_shared) |
| rc = -EINVAL; |
| break; |
| default: |
| rc = -EINVAL; |
| break; |
| } |
| if (rc) |
| break; |
| } |
| if (rc) |
| pr_err("Suspending the system failed because DCSS device %s " |
| "is writable\n", |
| dev_info->segment_name); |
| return rc; |
| } |
| |
| static int dcssblk_restore(struct device *dev) |
| { |
| struct dcssblk_dev_info *dev_info; |
| struct segment_info *entry; |
| unsigned long start, end; |
| int rc = 0; |
| |
| list_for_each_entry(dev_info, &dcssblk_devices, lh) { |
| list_for_each_entry(entry, &dev_info->seg_list, lh) { |
| segment_unload(entry->segment_name); |
| rc = segment_load(entry->segment_name, SEGMENT_SHARED, |
| &start, &end); |
| if (rc < 0) { |
| // TODO in_use check ? |
| segment_warning(rc, entry->segment_name); |
| goto out_panic; |
| } |
| if (start != entry->start || end != entry->end) { |
| pr_err("The address range of DCSS %s changed " |
| "while the system was suspended\n", |
| entry->segment_name); |
| goto out_panic; |
| } |
| } |
| } |
| return 0; |
| out_panic: |
| panic("fatal dcssblk resume error\n"); |
| } |
| |
| static int dcssblk_thaw(struct device *dev) |
| { |
| return 0; |
| } |
| |
| static const struct dev_pm_ops dcssblk_pm_ops = { |
| .freeze = dcssblk_freeze, |
| .thaw = dcssblk_thaw, |
| .restore = dcssblk_restore, |
| }; |
| |
| static struct platform_driver dcssblk_pdrv = { |
| .driver = { |
| .name = "dcssblk", |
| .pm = &dcssblk_pm_ops, |
| }, |
| }; |
| |
| static struct platform_device *dcssblk_pdev; |
| |
| |
| /* |
| * The init/exit functions. |
| */ |
| static void __exit |
| dcssblk_exit(void) |
| { |
| platform_device_unregister(dcssblk_pdev); |
| platform_driver_unregister(&dcssblk_pdrv); |
| root_device_unregister(dcssblk_root_dev); |
| unregister_blkdev(dcssblk_major, DCSSBLK_NAME); |
| } |
| |
| static int __init |
| dcssblk_init(void) |
| { |
| int rc; |
| |
| rc = platform_driver_register(&dcssblk_pdrv); |
| if (rc) |
| return rc; |
| |
| dcssblk_pdev = platform_device_register_simple("dcssblk", -1, NULL, |
| 0); |
| if (IS_ERR(dcssblk_pdev)) { |
| rc = PTR_ERR(dcssblk_pdev); |
| goto out_pdrv; |
| } |
| |
| dcssblk_root_dev = root_device_register("dcssblk"); |
| if (IS_ERR(dcssblk_root_dev)) { |
| rc = PTR_ERR(dcssblk_root_dev); |
| goto out_pdev; |
| } |
| rc = device_create_file(dcssblk_root_dev, &dev_attr_add); |
| if (rc) |
| goto out_root; |
| rc = device_create_file(dcssblk_root_dev, &dev_attr_remove); |
| if (rc) |
| goto out_root; |
| rc = register_blkdev(0, DCSSBLK_NAME); |
| if (rc < 0) |
| goto out_root; |
| dcssblk_major = rc; |
| init_rwsem(&dcssblk_devices_sem); |
| |
| dcssblk_check_params(); |
| return 0; |
| |
| out_root: |
| root_device_unregister(dcssblk_root_dev); |
| out_pdev: |
| platform_device_unregister(dcssblk_pdev); |
| out_pdrv: |
| platform_driver_unregister(&dcssblk_pdrv); |
| return rc; |
| } |
| |
| module_init(dcssblk_init); |
| module_exit(dcssblk_exit); |
| |
| module_param_string(segments, dcssblk_segments, DCSSBLK_PARM_LEN, 0444); |
| MODULE_PARM_DESC(segments, "Name of DCSS segment(s) to be loaded, " |
| "comma-separated list, names in each set separated " |
| "by commas are separated by colons, each set contains " |
| "names of contiguous segments and each name max. 8 chars.\n" |
| "Adding \"(local)\" to the end of each set equals echoing 0 " |
| "to /sys/devices/dcssblk/<device name>/shared after loading " |
| "the contiguous segments - \n" |
| "e.g. segments=\"mydcss1,mydcss2:mydcss3,mydcss4(local)\""); |
| |
| MODULE_LICENSE("GPL"); |