| /* |
| * dcssblk.c -- the S/390 block driver for dcss memory |
| * |
| * Authors: Carsten Otte, Stefan Weinhuber, Gerald Schaefer |
| */ |
| |
| #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 <asm/extmem.h> |
| #include <asm/io.h> |
| #include <linux/completion.h> |
| #include <linux/interrupt.h> |
| #include <asm/s390_rdev.h> |
| |
| //#define DCSSBLK_DEBUG /* Debug messages on/off */ |
| #define DCSSBLK_NAME "dcssblk" |
| #define DCSSBLK_MINORS_PER_DISK 1 |
| #define DCSSBLK_PARM_LEN 400 |
| |
| #ifdef DCSSBLK_DEBUG |
| #define PRINT_DEBUG(x...) printk(KERN_DEBUG DCSSBLK_NAME " debug: " x) |
| #else |
| #define PRINT_DEBUG(x...) do {} while (0) |
| #endif |
| #define PRINT_INFO(x...) printk(KERN_INFO DCSSBLK_NAME " info: " x) |
| #define PRINT_WARN(x...) printk(KERN_WARNING DCSSBLK_NAME " warning: " x) |
| #define PRINT_ERR(x...) printk(KERN_ERR DCSSBLK_NAME " error: " x) |
| |
| |
| static int dcssblk_open(struct inode *inode, struct file *filp); |
| static int dcssblk_release(struct inode *inode, struct file *filp); |
| static int dcssblk_make_request(struct request_queue *q, struct bio *bio); |
| static int dcssblk_direct_access(struct block_device *bdev, sector_t secnum, |
| void **kaddr, unsigned long *pfn); |
| |
| static char dcssblk_segments[DCSSBLK_PARM_LEN] = "\0"; |
| |
| static int dcssblk_major; |
| static struct block_device_operations dcssblk_devops = { |
| .owner = THIS_MODULE, |
| .open = dcssblk_open, |
| .release = dcssblk_release, |
| .direct_access = dcssblk_direct_access, |
| }; |
| |
| 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 ssize_t dcssblk_save_store(struct device * dev, struct device_attribute *attr, const char * buf, |
| size_t count); |
| static ssize_t dcssblk_save_show(struct device *dev, struct device_attribute *attr, char *buf); |
| static ssize_t dcssblk_shared_store(struct device * dev, struct device_attribute *attr, const char * buf, |
| size_t count); |
| static ssize_t dcssblk_shared_show(struct device *dev, struct device_attribute *attr, char *buf); |
| |
| static DEVICE_ATTR(add, S_IWUSR, NULL, dcssblk_add_store); |
| static DEVICE_ATTR(remove, S_IWUSR, NULL, dcssblk_remove_store); |
| static DEVICE_ATTR(save, S_IWUSR | S_IRUGO, dcssblk_save_show, |
| dcssblk_save_store); |
| static DEVICE_ATTR(shared, S_IWUSR | S_IRUGO, dcssblk_shared_show, |
| dcssblk_shared_store); |
| |
| static struct device *dcssblk_root_dev; |
| |
| struct dcssblk_dev_info { |
| struct list_head lh; |
| struct device dev; |
| char segment_name[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; |
| }; |
| |
| 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) |
| { |
| PRINT_DEBUG("segment release fn called for %s\n", dev->bus_id); |
| kfree(container_of(dev, struct dcssblk_dev_info, dev)); |
| 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 == MINOR(disk_devt(entry->gd))) |
| 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; |
| } |
| |
| static void dcssblk_unregister_callback(struct device *dev) |
| { |
| device_unregister(dev); |
| put_device(dev); |
| } |
| |
| /* |
| * 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; |
| 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)) { |
| PRINT_ERR("share: segment %s is busy!\n", |
| dev_info->segment_name); |
| rc = -EBUSY; |
| goto out; |
| } |
| if (inbuf[0] == '1') { |
| // reload segment in shared mode |
| rc = segment_modify_shared(dev_info->segment_name, |
| SEGMENT_SHARED); |
| if (rc < 0) { |
| BUG_ON(rc == -EINVAL); |
| if (rc != -EAGAIN) |
| goto removeseg; |
| } else { |
| 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 segment in exclusive mode |
| if (dev_info->segment_type == SEG_TYPE_SC) { |
| PRINT_ERR("Segment type SC (%s) cannot be loaded in " |
| "non-shared mode\n", dev_info->segment_name); |
| rc = -EINVAL; |
| goto out; |
| } |
| rc = segment_modify_shared(dev_info->segment_name, |
| SEGMENT_EXCLUSIVE); |
| if (rc < 0) { |
| BUG_ON(rc == -EINVAL); |
| if (rc != -EAGAIN) |
| goto removeseg; |
| } else { |
| dev_info->is_shared = 0; |
| set_disk_ro(dev_info->gd, 0); |
| } |
| } else { |
| rc = -EINVAL; |
| goto out; |
| } |
| rc = count; |
| goto out; |
| |
| removeseg: |
| PRINT_ERR("Could not reload segment %s, removing it now!\n", |
| dev_info->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); |
| rc = device_schedule_callback(dev, dcssblk_unregister_callback); |
| out: |
| up_write(&dcssblk_devices_sem); |
| return rc; |
| } |
| |
| /* |
| * 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; |
| |
| 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 |
| PRINT_INFO("Saving segment %s\n", |
| dev_info->segment_name); |
| segment_save(dev_info->segment_name); |
| } else { |
| // device is busy => we save it when it becomes |
| // idle in dcssblk_release |
| PRINT_INFO("Segment %s is currently busy, it 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; |
| PRINT_INFO("Pending save for segment %s deactivated\n", |
| dev_info->segment_name); |
| } |
| } else { |
| up_write(&dcssblk_devices_sem); |
| return -EINVAL; |
| } |
| up_write(&dcssblk_devices_sem); |
| return count; |
| } |
| |
| /* |
| * 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; |
| struct dcssblk_dev_info *dev_info; |
| char *local_buf; |
| unsigned long seg_byte_size; |
| |
| dev_info = NULL; |
| if (dev != dcssblk_root_dev) { |
| rc = -EINVAL; |
| goto out_nobuf; |
| } |
| local_buf = kmalloc(count + 1, GFP_KERNEL); |
| if (local_buf == NULL) { |
| rc = -ENOMEM; |
| goto out_nobuf; |
| } |
| /* |
| * parse input |
| */ |
| for (i = 0; ((buf[i] != '\0') && (buf[i] != '\n') && i < count); i++) { |
| local_buf[i] = toupper(buf[i]); |
| } |
| local_buf[i] = '\0'; |
| if ((i == 0) || (i > 8)) { |
| rc = -ENAMETOOLONG; |
| goto out; |
| } |
| /* |
| * already loaded? |
| */ |
| down_read(&dcssblk_devices_sem); |
| dev_info = dcssblk_get_device_by_name(local_buf); |
| up_read(&dcssblk_devices_sem); |
| if (dev_info != NULL) { |
| PRINT_WARN("Segment %s already loaded!\n", local_buf); |
| rc = -EEXIST; |
| goto out; |
| } |
| /* |
| * get a struct dcssblk_dev_info |
| */ |
| 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); |
| strlcpy(dev_info->dev.bus_id, local_buf, BUS_ID_SIZE); |
| dev_info->dev.release = dcssblk_release_segment; |
| INIT_LIST_HEAD(&dev_info->lh); |
| |
| dev_info->gd = alloc_disk(DCSSBLK_MINORS_PER_DISK); |
| if (dev_info->gd == NULL) { |
| rc = -ENOMEM; |
| goto free_dev_info; |
| } |
| 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_hardsect_size(dev_info->dcssblk_queue, 4096); |
| /* |
| * load the segment |
| */ |
| rc = segment_load(local_buf, SEGMENT_SHARED, |
| &dev_info->start, &dev_info->end); |
| if (rc < 0) { |
| segment_warning(rc, dev_info->segment_name); |
| goto dealloc_gendisk; |
| } |
| seg_byte_size = (dev_info->end - dev_info->start + 1); |
| set_capacity(dev_info->gd, seg_byte_size >> 9); // size in sectors |
| PRINT_INFO("Loaded segment %s, size = %lu Byte, " |
| "capacity = %lu (512 Byte) sectors\n", local_buf, |
| seg_byte_size, seg_byte_size >> 9); |
| |
| dev_info->segment_type = rc; |
| 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_device_by_name(local_buf)) { |
| up_write(&dcssblk_devices_sem); |
| rc = -EEXIST; |
| goto unload_seg; |
| } |
| rc = dcssblk_assign_free_minor(dev_info); |
| if (rc) { |
| up_write(&dcssblk_devices_sem); |
| PRINT_ERR("No free minor number available! " |
| "Unloading segment...\n"); |
| goto unload_seg; |
| } |
| sprintf(dev_info->gd->disk_name, "dcssblk%d", |
| MINOR(disk_devt(dev_info->gd))); |
| list_add_tail(&dev_info->lh, &dcssblk_devices); |
| |
| if (!try_module_get(THIS_MODULE)) { |
| rc = -ENODEV; |
| goto list_del; |
| } |
| /* |
| * register the device |
| */ |
| rc = device_register(&dev_info->dev); |
| if (rc) { |
| PRINT_ERR("Segment %s could not be registered RC=%d\n", |
| local_buf, rc); |
| module_put(THIS_MODULE); |
| goto list_del; |
| } |
| get_device(&dev_info->dev); |
| rc = device_create_file(&dev_info->dev, &dev_attr_shared); |
| if (rc) |
| goto unregister_dev; |
| rc = device_create_file(&dev_info->dev, &dev_attr_save); |
| if (rc) |
| goto unregister_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; |
| } |
| PRINT_DEBUG("Segment %s loaded successfully\n", local_buf); |
| up_write(&dcssblk_devices_sem); |
| rc = count; |
| goto out; |
| |
| unregister_dev: |
| list_del(&dev_info->lh); |
| blk_cleanup_queue(dev_info->dcssblk_queue); |
| dev_info->gd->queue = NULL; |
| put_disk(dev_info->gd); |
| device_unregister(&dev_info->dev); |
| segment_unload(dev_info->segment_name); |
| put_device(&dev_info->dev); |
| up_write(&dcssblk_devices_sem); |
| goto out; |
| list_del: |
| list_del(&dev_info->lh); |
| up_write(&dcssblk_devices_sem); |
| unload_seg: |
| segment_unload(local_buf); |
| dealloc_gendisk: |
| blk_cleanup_queue(dev_info->dcssblk_queue); |
| dev_info->gd->queue = NULL; |
| put_disk(dev_info->gd); |
| free_dev_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; |
| 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; ((*(buf+i)!='\0') && (*(buf+i)!='\n') && i < count); 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); |
| PRINT_WARN("Segment %s is not loaded!\n", local_buf); |
| rc = -ENODEV; |
| goto out_buf; |
| } |
| if (atomic_read(&dev_info->use_count) != 0) { |
| up_write(&dcssblk_devices_sem); |
| PRINT_WARN("Segment %s 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); |
| segment_unload(dev_info->segment_name); |
| PRINT_DEBUG("Segment %s unloaded successfully\n", |
| dev_info->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 inode *inode, struct file *filp) |
| { |
| struct dcssblk_dev_info *dev_info; |
| int rc; |
| |
| dev_info = inode->i_bdev->bd_disk->private_data; |
| if (NULL == dev_info) { |
| rc = -ENODEV; |
| goto out; |
| } |
| atomic_inc(&dev_info->use_count); |
| inode->i_bdev->bd_block_size = 4096; |
| rc = 0; |
| out: |
| return rc; |
| } |
| |
| static int |
| dcssblk_release(struct inode *inode, struct file *filp) |
| { |
| struct dcssblk_dev_info *dev_info; |
| int rc; |
| |
| dev_info = inode->i_bdev->bd_disk->private_data; |
| if (NULL == dev_info) { |
| rc = -ENODEV; |
| goto out; |
| } |
| down_write(&dcssblk_devices_sem); |
| if (atomic_dec_and_test(&dev_info->use_count) |
| && (dev_info->save_pending)) { |
| PRINT_INFO("Segment %s became idle and is being saved now\n", |
| dev_info->segment_name); |
| segment_save(dev_info->segment_name); |
| dev_info->save_pending = 0; |
| } |
| up_write(&dcssblk_devices_sem); |
| rc = 0; |
| out: |
| return rc; |
| } |
| |
| static int |
| dcssblk_make_request(struct request_queue *q, struct bio *bio) |
| { |
| struct dcssblk_dev_info *dev_info; |
| struct bio_vec *bvec; |
| unsigned long index; |
| unsigned long page_addr; |
| unsigned long source_addr; |
| unsigned long bytes_done; |
| int i; |
| |
| bytes_done = 0; |
| dev_info = bio->bi_bdev->bd_disk->private_data; |
| if (dev_info == NULL) |
| goto fail; |
| if ((bio->bi_sector & 7) != 0 || (bio->bi_size & 4095) != 0) |
| /* Request is not page-aligned. */ |
| goto fail; |
| if (((bio->bi_size >> 9) + bio->bi_sector) |
| > 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) { |
| PRINT_WARN("rejecting write to ro segment %s\n", dev_info->dev.bus_id); |
| goto fail; |
| } |
| } |
| } |
| |
| index = (bio->bi_sector >> 3); |
| bio_for_each_segment(bvec, bio, i) { |
| 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, 0); |
| return 0; |
| fail: |
| bio_io_error(bio); |
| return 0; |
| } |
| |
| static int |
| dcssblk_direct_access (struct block_device *bdev, sector_t secnum, |
| void **kaddr, unsigned long *pfn) |
| { |
| struct dcssblk_dev_info *dev_info; |
| unsigned long pgoff; |
| |
| dev_info = bdev->bd_disk->private_data; |
| if (!dev_info) |
| return -ENODEV; |
| if (secnum % (PAGE_SIZE/512)) |
| return -EINVAL; |
| pgoff = secnum / (PAGE_SIZE / 512); |
| if ((pgoff+1)*PAGE_SIZE-1 > dev_info->end - dev_info->start) |
| return -ERANGE; |
| *kaddr = (void *) (dev_info->start+pgoff*PAGE_SIZE); |
| *pfn = virt_to_phys(*kaddr) >> PAGE_SHIFT; |
| |
| return 0; |
| } |
| |
| static void |
| dcssblk_check_params(void) |
| { |
| int rc, i, j, k; |
| char buf[9]; |
| struct dcssblk_dev_info *dev_info; |
| |
| for (i = 0; (i < DCSSBLK_PARM_LEN) && (dcssblk_segments[i] != '\0'); |
| i++) { |
| for (j = i; (dcssblk_segments[j] != ',') && |
| (dcssblk_segments[j] != '\0') && |
| (dcssblk_segments[j] != '(') && |
| (j - i) < 8; 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] != '\0'; k++) |
| buf[k] = toupper(buf[k]); |
| 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; |
| } |
| } |
| |
| /* |
| * The init/exit functions. |
| */ |
| static void __exit |
| dcssblk_exit(void) |
| { |
| s390_root_dev_unregister(dcssblk_root_dev); |
| unregister_blkdev(dcssblk_major, DCSSBLK_NAME); |
| } |
| |
| static int __init |
| dcssblk_init(void) |
| { |
| int rc; |
| |
| dcssblk_root_dev = s390_root_dev_register("dcssblk"); |
| if (IS_ERR(dcssblk_root_dev)) |
| return PTR_ERR(dcssblk_root_dev); |
| rc = device_create_file(dcssblk_root_dev, &dev_attr_add); |
| if (rc) { |
| s390_root_dev_unregister(dcssblk_root_dev); |
| return rc; |
| } |
| rc = device_create_file(dcssblk_root_dev, &dev_attr_remove); |
| if (rc) { |
| s390_root_dev_unregister(dcssblk_root_dev); |
| return rc; |
| } |
| rc = register_blkdev(0, DCSSBLK_NAME); |
| if (rc < 0) { |
| s390_root_dev_unregister(dcssblk_root_dev); |
| return rc; |
| } |
| dcssblk_major = rc; |
| init_rwsem(&dcssblk_devices_sem); |
| |
| dcssblk_check_params(); |
| |
| return 0; |
| } |
| |
| 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, each name max. 8 chars.\n" |
| "Adding \"(local)\" to segment name equals echoing 0 to " |
| "/sys/devices/dcssblk/<segment name>/shared after loading " |
| "the segment - \n" |
| "e.g. segments=\"mydcss1,mydcss2,mydcss3(local)\""); |
| |
| MODULE_LICENSE("GPL"); |