const: make block_device_operations const
[linux-3.10.git] / drivers / s390 / block / dcssblk.c
index 3faf053..f76f4bd 100644 (file)
@@ -4,6 +4,9 @@
  * 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/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>
+#include <linux/platform_device.h>
+#include <asm/extmem.h>
+#include <asm/io.h>
 
-//#define DCSSBLK_DEBUG                /* Debug messages on/off */
 #define DCSSBLK_NAME "dcssblk"
 #define DCSSBLK_MINORS_PER_DISK 1
 #define DCSSBLK_PARM_LEN 400
+#define DCSS_BUS_ID_SIZE 20
 
-#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_open(struct block_device *bdev, fmode_t mode);
+static int dcssblk_release(struct gendisk *disk, fmode_t mode);
 static int dcssblk_make_request(struct request_queue *q, struct bio *bio);
 static int dcssblk_direct_access(struct block_device *bdev, sector_t secnum,
-                                unsigned long *data);
+                                void **kaddr, unsigned long *pfn);
 
 static char dcssblk_segments[DCSSBLK_PARM_LEN] = "\0";
 
 static int dcssblk_major;
-static struct block_device_operations dcssblk_devops = {
+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,
@@ -58,30 +75,20 @@ static ssize_t dcssblk_save_show(struct device *dev, struct device_attribute *at
 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 ssize_t dcssblk_seglist_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,
+static DEVICE_ATTR(save, S_IWUSR | S_IRUSR, dcssblk_save_show,
                   dcssblk_save_store);
-static DEVICE_ATTR(shared, S_IWUSR | S_IRUGO, dcssblk_shared_show,
+static DEVICE_ATTR(shared, S_IWUSR | S_IRUSR, dcssblk_shared_show,
                   dcssblk_shared_store);
+static DEVICE_ATTR(seglist, S_IRUSR, dcssblk_seglist_show, NULL);
 
 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;
 
@@ -91,8 +98,15 @@ static struct rw_semaphore dcssblk_devices_sem;
 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));
+       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);
 }
 
@@ -143,54 +157,165 @@ dcssblk_get_device_by_name(char *name)
 }
 
 /*
- * print appropriate error message for segment_load()/segment_type()
- * return code
+ * get the struct segment_info from seg_list
+ * for the given name.
+ * down_read(&dcssblk_devices_sem) must be held.
  */
-static void
-dcssblk_segment_warn(int rc, char* seg_name)
+static struct segment_info *
+dcssblk_get_segment_by_name(char *name)
 {
-       switch (rc) {
-       case -ENOENT:
-               PRINT_WARN("cannot load/query segment %s, does not exist\n",
-                          seg_name);
-               break;
-       case -ENOSYS:
-               PRINT_WARN("cannot load/query segment %s, not running on VM\n",
-                          seg_name);
-               break;
-       case -EIO:
-               PRINT_WARN("cannot load/query segment %s, hardware error\n",
-                          seg_name);
-               break;
-       case -ENOTSUPP:
-               PRINT_WARN("cannot load/query segment %s, is a multi-part "
-                          "segment\n", seg_name);
-               break;
-       case -ENOSPC:
-               PRINT_WARN("cannot load/query segment %s, overlaps with "
-                          "storage\n", seg_name);
-               break;
-       case -EBUSY:
-               PRINT_WARN("cannot load/query segment %s, overlaps with "
-                          "already loaded dcss\n", seg_name);
-               break;
-       case -EPERM:
-               PRINT_WARN("cannot load/query segment %s, already loaded in "
-                          "incompatible mode\n", seg_name);
-               break;
-       case -ENOMEM:
-               PRINT_WARN("cannot load/query segment %s, out of memory\n",
-                          seg_name);
-               break;
-       case -ERANGE:
-               PRINT_WARN("cannot load/query segment %s, exceeds kernel "
-                          "mapping range\n", seg_name);
-               break;
-       default:
-               PRINT_WARN("cannot load/query segment %s, return value %i\n",
-                          seg_name, rc);
-               break;
+       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;
 }
 
 static void dcssblk_unregister_callback(struct device *dev)
@@ -216,57 +341,56 @@ 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')) {
-               PRINT_WARN("Invalid value, must be 0 or 1\n");
+       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);
+               /* 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 segment in exclusive mode
+               /* reload segments 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);
+                       pr_err("DCSS %s is of type SC and cannot be "
+                              "loaded as exclusive-writable\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);
+               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 {
-               PRINT_WARN("Invalid value, must be 0 or 1\n");
                rc = -EINVAL;
                goto out;
        }
@@ -274,8 +398,13 @@ dcssblk_shared_store(struct device *dev, struct device_attribute *attr, const ch
        goto out;
 
 removeseg:
-       PRINT_ERR("Could not reload segment %s, removing it now!\n",
-                       dev_info->segment_name);
+       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);
@@ -308,26 +437,27 @@ 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')) {
-               PRINT_WARN("Invalid value, must be 0 or 1\n");
+       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);
+                       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) {
+                               segment_save(entry->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);
+                       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') {
@@ -335,12 +465,12 @@ dcssblk_save_store(struct device *dev, struct device_attribute *attr, const char
                        // 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);
+                       pr_info("A pending save request for device %s "
+                               "has been canceled\n",
+                               dev_info->segment_name);
                }
        } else {
                up_write(&dcssblk_devices_sem);
-               PRINT_WARN("Invalid value, must be 0 or 1\n");
                return -EINVAL;
        }
        up_write(&dcssblk_devices_sem);
@@ -348,66 +478,123 @@ dcssblk_save_store(struct device *dev, struct device_attribute *attr, const char
 }
 
 /*
+ * 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;
+}
+
+/*
  * 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;
+       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; ((buf[i] != '\0') && (buf[i] != '\n') && i < count); i++) {
-               local_buf[i] = toupper(buf[i]);
+               for (j = i; (buf[j] != ':') &&
+                       (buf[j] != '\0') &&
+                       (buf[j] != '\n') &&
+                       j < count; 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;
        }
-       local_buf[i] = '\0';
-       if ((i == 0) || (i > 8)) {
+
+       /* no trailing colon at the end of the input */
+       if ((i > 0) && (buf[i-1] == ':')) {
                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;
+               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);
 
-       strcpy(dev_info->segment_name, local_buf);
-       strlcpy(dev_info->dev.bus_id, local_buf, BUS_ID_SIZE);
+       dev_set_name(&dev_info->dev, dev_info->segment_name);
        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;
+               goto seg_list_del;
        }
        dev_info->gd->major = dcssblk_major;
        dev_info->gd->fops = &dcssblk_devops;
@@ -416,55 +603,43 @@ dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char
        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) {
-               dcssblk_segment_warn(rc, dev_info->segment_name);
-               goto dealloc_gendisk;
-       }
+       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
-       PRINT_INFO("Loaded segment %s, size = %lu Byte, "
-                  "capacity = %lu (512 Byte) sectors\n", local_buf,
-                  seg_byte_size, seg_byte_size >> 9);
+       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->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
+        *get minor, add to list
         */
        down_write(&dcssblk_devices_sem);
-       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;
+       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 list_del;
+               goto dev_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;
+               goto dev_list_del;
        }
        get_device(&dev_info->dev);
        rc = device_create_file(&dev_info->dev, &dev_attr_shared);
@@ -473,6 +648,9 @@ dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char
        rc = device_create_file(&dev_info->dev, &dev_attr_save);
        if (rc)
                goto unregister_dev;
+       rc = device_create_file(&dev_info->dev, &dev_attr_seglist);
+       if (rc)
+               goto unregister_dev;
 
        add_disk(dev_info->gd);
 
@@ -486,32 +664,37 @@ dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char
                        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:
-       PRINT_ERR("device_create_file() failed!\n");
        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);
+       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;
-list_del:
+dev_list_del:
        list_del(&dev_info->lh);
-       up_write(&dcssblk_devices_sem);
-unload_seg:
-       segment_unload(local_buf);
-dealloc_gendisk:
+release_gd:
        blk_cleanup_queue(dev_info->dcssblk_queue);
        dev_info->gd->queue = NULL;
        put_disk(dev_info->gd);
-free_dev_info:
+       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);
@@ -526,6 +709,7 @@ 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;
 
@@ -552,26 +736,30 @@ dcssblk_remove_store(struct device *dev, struct device_attribute *attr, const ch
        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);
+               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);
-               PRINT_WARN("Segment %s is in use!\n", local_buf);
+               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);
 
+       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);
+
+       /* 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);
 
@@ -582,40 +770,42 @@ out_buf:
 }
 
 static int
-dcssblk_open(struct inode *inode, struct file *filp)
+dcssblk_open(struct block_device *bdev, fmode_t mode)
 {
        struct dcssblk_dev_info *dev_info;
        int rc;
 
-       dev_info = inode->i_bdev->bd_disk->private_data;
+       dev_info = 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;
+       bdev->bd_block_size = 4096;
        rc = 0;
 out:
        return rc;
 }
 
 static int
-dcssblk_release(struct inode *inode, struct file *filp)
+dcssblk_release(struct gendisk *disk, fmode_t mode)
 {
-       struct dcssblk_dev_info *dev_info;
+       struct dcssblk_dev_info *dev_info = disk->private_data;
+       struct segment_info *entry;
        int rc;
 
-       dev_info = inode->i_bdev->bd_disk->private_data;
-       if (NULL == dev_info) {
+       if (!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);
+               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) {
+                       segment_save(entry->segment_name);
+               }
                dev_info->save_pending = 0;
        }
        up_write(&dcssblk_devices_sem);
@@ -655,7 +845,9 @@ dcssblk_make_request(struct request_queue *q, struct bio *bio)
                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);
+                               pr_warning("Writing to %s failed because it "
+                                          "is a read-only device\n",
+                                          dev_name(&dev_info->dev));
                                goto fail;
                        }
                }
@@ -666,7 +858,7 @@ dcssblk_make_request(struct request_queue *q, struct bio *bio)
                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)
+               if (unlikely((page_addr & 4095) != 0) || (bvec->bv_len & 4095) != 0)
                        // More paranoia.
                        goto fail;
                if (bio_data_dir(bio) == READ) {
@@ -687,7 +879,7 @@ fail:
 
 static int
 dcssblk_direct_access (struct block_device *bdev, sector_t secnum,
-                       unsigned long *data)
+                       void **kaddr, unsigned long *pfn)
 {
        struct dcssblk_dev_info *dev_info;
        unsigned long pgoff;
@@ -700,7 +892,9 @@ dcssblk_direct_access (struct block_device *bdev, sector_t secnum,
        pgoff = secnum / (PAGE_SIZE / 512);
        if ((pgoff+1)*PAGE_SIZE-1 > dev_info->end - dev_info->start)
                return -ERANGE;
-       *data = (unsigned long) (dev_info->start+pgoff*PAGE_SIZE);
+       *kaddr = (void *) (dev_info->start+pgoff*PAGE_SIZE);
+       *pfn = virt_to_phys(*kaddr) >> PAGE_SHIFT;
+
        return 0;
 }
 
@@ -708,7 +902,7 @@ static void
 dcssblk_check_params(void)
 {
        int rc, i, j, k;
-       char buf[9];
+       char buf[DCSSBLK_PARM_LEN + 1];
        struct dcssblk_dev_info *dev_info;
 
        for (i = 0; (i < DCSSBLK_PARM_LEN) && (dcssblk_segments[i] != '\0');
@@ -716,15 +910,16 @@ dcssblk_check_params(void)
                for (j = i; (dcssblk_segments[j] != ',')  &&
                            (dcssblk_segments[j] != '\0') &&
                            (dcssblk_segments[j] != '(')  &&
-                           (j - i) < 8; j++)
+                           (j < DCSSBLK_PARM_LEN); 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++)
+                       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);
@@ -746,15 +941,97 @@ dcssblk_check_params(void)
 }
 
 /*
+ * 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 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",
+               .owner  = THIS_MODULE,
+               .pm     = &dcssblk_pm_ops,
+       },
+};
+
+static struct platform_device *dcssblk_pdev;
+
+
+/*
  * The init/exit functions.
  */
 static void __exit
 dcssblk_exit(void)
 {
-       PRINT_DEBUG("DCSSBLOCK EXIT...\n");
-       s390_root_dev_unregister(dcssblk_root_dev);
+       platform_device_unregister(dcssblk_pdev);
+       platform_driver_unregister(&dcssblk_pdrv);
+       root_device_unregister(dcssblk_root_dev);
        unregister_blkdev(dcssblk_major, DCSSBLK_NAME);
-       PRINT_DEBUG("...finished!\n");
 }
 
 static int __init
@@ -762,37 +1039,44 @@ dcssblk_init(void)
 {
        int rc;
 
-       PRINT_DEBUG("DCSSBLOCK INIT...\n");
-       dcssblk_root_dev = s390_root_dev_register("dcssblk");
+       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)) {
-               PRINT_ERR("device_register() failed!\n");
-               return PTR_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) {
-               PRINT_ERR("device_create_file(add) failed!\n");
-               s390_root_dev_unregister(dcssblk_root_dev);
-               return rc;
-       }
+       if (rc)
+               goto out_root;
        rc = device_create_file(dcssblk_root_dev, &dev_attr_remove);
-       if (rc) {
-               PRINT_ERR("device_create_file(remove) failed!\n");
-               s390_root_dev_unregister(dcssblk_root_dev);
-               return rc;
-       }
+       if (rc)
+               goto out_root;
        rc = register_blkdev(0, DCSSBLK_NAME);
-       if (rc < 0) {
-               PRINT_ERR("Can't get dynamic major!\n");
-               s390_root_dev_unregister(dcssblk_root_dev);
-               return rc;
-       }
+       if (rc < 0)
+               goto out_root;
        dcssblk_major = rc;
        init_rwsem(&dcssblk_devices_sem);
 
        dcssblk_check_params();
-
-       PRINT_DEBUG("...finished!\n");
        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);
@@ -800,10 +1084,12 @@ 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)\"");
+                "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");