vserver 1.9.5.x5
[linux-2.6.git] / arch / s390 / mm / extmem.c
index b0b2714..648deed 100644 (file)
@@ -1,11 +1,10 @@
 /*
- * File...........: arch/s390/mm/dcss.c
- * Author(s)......: Steven Shultz <shultzss@us.ibm.com>
- *                  Carsten Otte <cotte@de.ibm.com>
+ * File...........: arch/s390/mm/extmem.c
+ * Author(s)......: Carsten Otte <cotte@de.ibm.com>
+ *                 Rob M van der Heij <rvdheij@nl.ibm.com>
+ *                 Steven Shultz <shultzss@us.ibm.com>
  * Bugreports.to..: <Linux390@de.ibm.com>
- * thanks to Rob M van der Heij
- * - he wrote the diag64 function
- * (C) IBM Corporation 2002
+ * (C) IBM Corporation 2002-2004
  */
 
 #include <linux/kernel.h>
 #define DCSS_FINDSEG    0x0c
 #define DCSS_LOADNOLY   0x10
 #define DCSS_SEGEXT     0x18
-#define DCSS_QACTV      0x0c
+#define DCSS_FINDSEGA   0x0c
+
+struct qrange {
+       unsigned int  start; // 3byte start address, 1 byte type
+       unsigned int  end;   // 3byte end address, 1 byte reserved
+};
+
+struct qout64 {
+       int segstart;
+       int segend;
+       int segcnt;
+       int segrcnt;
+       struct qrange range[6];
+};
+
+struct qin64 {
+       char qopcode;
+       char rsrv1[3];
+       char qrcode;
+       char rsrv2[3];
+       char qname[8];
+       unsigned int qoutptr;
+       short int qoutlen;
+};
 
 struct dcss_segment {
-        struct list_head list;
-        char dcss_name[8];
-        unsigned long start_addr;
-        unsigned long end;
-        atomic_t ref_count;
-        int dcss_attr;
-       int shared_attr;
+       struct list_head list;
+       char dcss_name[8];
+       unsigned long start_addr;
+       unsigned long end;
+       atomic_t ref_count;
+       int do_nonshared;
+       unsigned int vm_segtype;
+       struct qrange range[6];
+       int segcnt;
 };
 
-static spinlock_t dcss_lock = SPIN_LOCK_UNLOCKED;
+static DEFINE_SPINLOCK(dcss_lock);
 static struct list_head dcss_list = LIST_HEAD_INIT(dcss_list);
+static char *segtype_string[] = { "SW", "EW", "SR", "ER", "SN", "EN", "SC",
+                                       "EW/EN-MIXED" };
+
 extern struct {
        unsigned long addr, size, type;
 } memory_chunk[MEMORY_CHUNKS];
@@ -63,20 +90,46 @@ extern struct {
  * Create the 8 bytes, ebcdic VM segment name from
  * an ascii name.
  */
-static void inline dcss_mkname(char *name, char *dcss_name)
+static void inline
+dcss_mkname(char *name, char *dcss_name)
+{
+       int i;
+
+       for (i = 0; i < 8; i++) {
+               if (name[i] == '\0')
+                       break;
+               dcss_name[i] = toupper(name[i]);
+       };
+       for (; i < 8; i++)
+               dcss_name[i] = ' ';
+       ASCEBC(dcss_name, 8);
+}
+
+
+/*
+ * search all segments in dcss_list, and return the one
+ * namend *name. If not found, return NULL.
+ */
+static struct dcss_segment *
+segment_by_name (char *name)
 {
-        int i;
-
-        for (i = 0; i <= 8; i++) {
-                if (name[i] == '\0')
-                        break;
-                dcss_name[i] = toupper(name[i]);
-        };
-        for (; i <= 8; i++)
-                dcss_name[i] = ' ';
-        ASCEBC(dcss_name, 8);
+       char dcss_name[9];
+       struct list_head *l;
+       struct dcss_segment *tmp, *retval = NULL;
+
+       assert_spin_locked(&dcss_lock);
+       dcss_mkname (name, dcss_name);
+       list_for_each (l, &dcss_list) {
+               tmp = list_entry (l, struct dcss_segment, list);
+               if (memcmp(tmp->dcss_name, dcss_name, 8) == 0) {
+                       retval = tmp;
+                       break;
+               }
+       }
+       return retval;
 }
 
+
 /*
  * Perform a function on a dcss segment.
  */
@@ -84,337 +137,378 @@ static inline int
 dcss_diag (__u8 func, void *parameter,
            unsigned long *ret1, unsigned long *ret2)
 {
-        unsigned long rx, ry;
-        int rc;
+       unsigned long rx, ry;
+       int rc;
 
-        rx = (unsigned long) parameter;
-        ry = (unsigned long) func;
-        __asm__ __volatile__(
+       rx = (unsigned long) parameter;
+       ry = (unsigned long) func;
+       __asm__ __volatile__(
 #ifdef CONFIG_ARCH_S390X
-                             "   sam31\n" // switch to 31 bit
-                             "   diag    %0,%1,0x64\n"
-                             "   sam64\n" // switch back to 64 bit
+               "   sam31\n" // switch to 31 bit
+               "   diag    %0,%1,0x64\n"
+               "   sam64\n" // switch back to 64 bit
 #else
-                             "   diag    %0,%1,0x64\n"
+               "   diag    %0,%1,0x64\n"
 #endif
-                             "   ipm     %2\n"
-                             "   srl     %2,28\n"
-                             : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc" );
-        *ret1 = rx;
-        *ret2 = ry;
-        return rc;
+               "   ipm     %2\n"
+               "   srl     %2,28\n"
+               : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc" );
+       *ret1 = rx;
+       *ret2 = ry;
+       return rc;
+}
+
+static inline int
+dcss_diag_translate_rc (int vm_rc) {
+       if (vm_rc == 44)
+               return -ENOENT;
+       return -EIO;
+}
+
+
+/* do a diag to get info about a segment.
+ * fills start_address, end and vm_segtype fields
+ */
+static int
+query_segment_type (struct dcss_segment *seg)
+{
+       struct qin64  *qin = kmalloc (sizeof(struct qin64), GFP_DMA);
+       struct qout64 *qout = kmalloc (sizeof(struct qout64), GFP_DMA);
+
+       int diag_cc, rc, i;
+       unsigned long dummy, vmrc;
+
+       if ((qin == NULL) || (qout == NULL)) {
+               rc = -ENOMEM;
+               goto out_free;
+       }
+
+       /* initialize diag input parameters */
+       qin->qopcode = DCSS_FINDSEGA;
+       qin->qoutptr = (unsigned long) qout;
+       qin->qoutlen = sizeof(struct qout64);
+       memcpy (qin->qname, seg->dcss_name, 8);
+
+       diag_cc = dcss_diag (DCSS_SEGEXT, qin, &dummy, &vmrc);
+
+       if (diag_cc > 1) {
+               rc = dcss_diag_translate_rc (vmrc);
+               goto out_free;
+       }
+
+       if (qout->segcnt > 6) {
+               rc = -ENOTSUPP;
+               goto out_free;
+       }
+
+       if (qout->segcnt == 1) {
+               seg->vm_segtype = qout->range[0].start & 0xff;
+       } else {
+               /* multi-part segment. only one type supported here:
+                   - all parts are contiguous
+                   - all parts are either EW or EN type
+                   - maximum 6 parts allowed */
+               unsigned long start = qout->segstart >> PAGE_SHIFT;
+               for (i=0; i<qout->segcnt; i++) {
+                       if (((qout->range[i].start & 0xff) != SEG_TYPE_EW) &&
+                           ((qout->range[i].start & 0xff) != SEG_TYPE_EN)) {
+                               rc = -ENOTSUPP;
+                               goto out_free;
+                       }
+                       if (start != qout->range[i].start >> PAGE_SHIFT) {
+                               rc = -ENOTSUPP;
+                               goto out_free;
+                       }
+                       start = (qout->range[i].end >> PAGE_SHIFT) + 1;
+               }
+               seg->vm_segtype = SEG_TYPE_EWEN;
+       }
+
+       /* analyze diag output and update seg */
+       seg->start_addr = qout->segstart;
+       seg->end = qout->segend;
+
+       memcpy (seg->range, qout->range, 6*sizeof(struct qrange));
+       seg->segcnt = qout->segcnt;
+
+       rc = 0;
+
+ out_free:
+       if (qin) kfree(qin);
+       if (qout) kfree(qout);
+       return rc;
+}
+
+/*
+ * check if the given segment collides with guest storage.
+ * returns 1 if this is the case, 0 if no collision was found
+ */
+static int
+segment_overlaps_storage(struct dcss_segment *seg)
+{
+       int i;
+
+       for (i=0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
+               if (memory_chunk[i].type != 0)
+                       continue;
+               if ((memory_chunk[i].addr >> 20) > (seg->end >> 20))
+                       continue;
+               if (((memory_chunk[i].addr + memory_chunk[i].size - 1) >> 20)
+                               < (seg->start_addr >> 20))
+                       continue;
+               return 1;
+       }
+       return 0;
 }
 
+/*
+ * check if segment collides with other segments that are currently loaded
+ * returns 1 if this is the case, 0 if no collision was found
+ */
+static int
+segment_overlaps_others (struct dcss_segment *seg)
+{
+       struct list_head *l;
+       struct dcss_segment *tmp;
+
+       assert_spin_locked(&dcss_lock);
+       list_for_each(l, &dcss_list) {
+               tmp = list_entry(l, struct dcss_segment, list);
+               if ((tmp->start_addr >> 20) > (seg->end >> 20))
+                       continue;
+               if ((tmp->end >> 20) < (seg->start_addr >> 20))
+                       continue;
+               if (seg == tmp)
+                       continue;
+               return 1;
+       }
+       return 0;
+}
 
-/* use to issue "extended" dcss query */
+/*
+ * check if segment exceeds the kernel mapping range (detected or set via mem=)
+ * returns 1 if this is the case, 0 if segment fits into the range
+ */
 static inline int
-dcss_diag_query(char *name, int *rwattr, int *shattr, unsigned long *segstart, unsigned long *segend)
+segment_exceeds_range (struct dcss_segment *seg)
 {
-        int i,j,rc;
-        unsigned long  rx, ry;
-
-        typedef struct segentry {
-                char thisseg[8];
-        } segentry;
-
-        struct qout64 {
-                int segstart;
-                int segend;
-                int segcnt;
-                int segrcnt;
-                segentry segout[6];
-        };
-
-        struct qin64 {
-                char qopcode;
-                char rsrv1[3];
-                char qrcode;
-                char rsrv2[3];
-                char qname[8];
-                unsigned int qoutptr;
-                short int qoutlen;
-        };
-
-
-        struct qin64  *qinarea;
-        struct qout64 *qoutarea;
-
-        qinarea = (struct qin64*) get_zeroed_page (GFP_DMA);
-        if (!qinarea) {
-                rc =-ENOMEM;
-                goto out;
-        }
-        qoutarea = (struct qout64*) get_zeroed_page (GFP_DMA);
-        if (!qoutarea) {
-                rc = -ENOMEM;
-                free_page ((unsigned long) qinarea);
-                goto out;
-        }
-        memset (qinarea,0,PAGE_SIZE);
-        memset (qoutarea,0,PAGE_SIZE);
-
-        qinarea->qopcode = DCSS_QACTV; /* do a query for active
-                                          segments */
-        qinarea->qoutptr = (unsigned long) qoutarea;
-        qinarea->qoutlen = sizeof(struct qout64);
-
-        /* Move segment name into double word aligned
-           field and pad with blanks to 8 long.
-         */
-
-        for (i = j = 0 ; i < 8; i++) {
-                qinarea->qname[i] = (name[j] == '\0') ? ' ' : name[j++];
-        }
-
-        /* name already in EBCDIC */
-        /* ASCEBC ((void *)&qinarea.qname, 8); */
-
-        /* set the assembler variables */
-        rx = (unsigned long) qinarea;
-        ry = DCSS_SEGEXT; /* this is extended function */
-
-        /* issue diagnose x'64' */
-        __asm__ __volatile__(
-#ifdef CONFIG_ARCH_S390X
-                             "   sam31\n" // switch to 31 bit
-                             "   diag    %0,%1,0x64\n"
-                             "   sam64\n" // switch back to 64 bit
-#else
-                             "   diag    %0,%1,0x64\n"
-#endif
-                             "   ipm     %2\n"
-                             "   srl     %2,28\n"
-                             : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc" );
-
-        /* parse the query output area */
-       *segstart=qoutarea->segstart;
-       *segend=qoutarea->segend;
-
-        if (rc > 1)
-                {
-                        *rwattr = 2;
-                        *shattr = 2;
-                        rc = 0;
-                        goto free;
-                }
-
-        if (qoutarea->segcnt > 6)
-                {
-                        *rwattr = 3;
-                        *shattr = 3;
-                        rc = 0;
-                        goto free;
-                }
-
-        *rwattr = 1;
-        *shattr = 1;
-
-        for (i=0; i < qoutarea->segrcnt; i++) {
-                if (qoutarea->segout[i].thisseg[3] == 2 ||
-                    qoutarea->segout[i].thisseg[3] == 3 ||
-                    qoutarea->segout[i].thisseg[3] == 6 )
-                        *rwattr = 0;
-                if (qoutarea->segout[i].thisseg[3] == 1 ||
-                    qoutarea->segout[i].thisseg[3] == 3 ||
-                    qoutarea->segout[i].thisseg[3] == 5 )
-                        *shattr = 0;
-        } /* end of for statement */
-        rc = 0;
- free:
-        free_page ((unsigned long) qoutarea);
-        free_page ((unsigned long) qinarea);
+       int seg_last_pfn = (seg->end) >> PAGE_SHIFT;
+       if (seg_last_pfn > max_pfn)
+               return 1;
+       return 0;
+}
+
+/*
+ * get info about a segment
+ * possible return values:
+ * -ENOSYS  : we are not running on VM
+ * -EIO     : could not perform query diagnose
+ * -ENOENT  : no such segment
+ * -ENOTSUPP: multi-part segment cannot be used with linux
+ * -ENOSPC  : segment cannot be used (overlaps with storage)
+ * -ENOMEM  : out of memory
+ * 0 .. 6   : type of segment as defined in include/asm-s390/extmem.h
+ */
+int
+segment_type (char* name)
+{
+       int rc;
+       struct dcss_segment seg;
+
+       if (!MACHINE_IS_VM)
+               return -ENOSYS;
+
+       dcss_mkname(name, seg.dcss_name);
+       rc = query_segment_type (&seg);
+       if (rc < 0)
+               return rc;
+       return seg.vm_segtype;
+}
+
+/*
+ * real segment loading function, called from segment_load
+ */
+static int
+__segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long *end)
+{
+       struct dcss_segment *seg = kmalloc(sizeof(struct dcss_segment),
+                       GFP_DMA);
+       int dcss_command, rc, diag_cc;
+
+       if (seg == NULL) {
+               rc = -ENOMEM;
+               goto out;
+       }
+       dcss_mkname (name, seg->dcss_name);
+       rc = query_segment_type (seg);
+       if (rc < 0)
+               goto out_free;
+       if (segment_exceeds_range(seg)) {
+               PRINT_WARN ("segment_load: not loading segment %s - exceeds"
+                               " kernel mapping range\n",name);
+               rc = -ERANGE;
+               goto out_free;
+       }
+       if (segment_overlaps_storage(seg)) {
+               PRINT_WARN ("segment_load: not loading segment %s - overlaps"
+                               " storage\n",name);
+               rc = -ENOSPC;
+               goto out_free;
+       }
+       if (segment_overlaps_others(seg)) {
+               PRINT_WARN ("segment_load: not loading segment %s - overlaps"
+                               " other segments\n",name);
+               rc = -EBUSY;
+               goto out_free;
+       }
+       if (do_nonshared)
+               dcss_command = DCSS_LOADNSR;
+       else
+               dcss_command = DCSS_LOADNOLY;
+
+       diag_cc = dcss_diag(dcss_command, seg->dcss_name,
+                       &seg->start_addr, &seg->end);
+       if (diag_cc > 1) {
+               PRINT_WARN ("segment_load: could not load segment %s - "
+                               "diag returned error (%ld)\n",name,seg->end);
+               rc = dcss_diag_translate_rc (seg->end);
+               dcss_diag(DCSS_PURGESEG, seg->dcss_name,
+                               &seg->start_addr, &seg->end);
+               goto out_free;
+       }
+       seg->do_nonshared = do_nonshared;
+       atomic_set(&seg->ref_count, 1);
+       list_add(&seg->list, &dcss_list);
+       rc = seg->vm_segtype;
+       *addr = seg->start_addr;
+       *end  = seg->end;
+       if (do_nonshared)
+               PRINT_INFO ("segment_load: loaded segment %s range %p .. %p "
+                               "type %s in non-shared mode\n", name,
+                               (void*)seg->start_addr, (void*)seg->end,
+                               segtype_string[seg->vm_segtype]);
+       else
+               PRINT_INFO ("segment_load: loaded segment %s range %p .. %p "
+                               "type %s in shared mode\n", name,
+                               (void*)seg->start_addr, (void*)seg->end,
+                               segtype_string[seg->vm_segtype]);
+       goto out;
+ out_free:
+       kfree (seg);
  out:
-        return rc;
+       return rc;
 }
 
 /*
- * Load a DCSS segment via the diag 0x64.
+ * this function loads a DCSS segment
+ * name         : name of the DCSS
+ * do_nonshared : 0 indicates that the dcss should be shared with other linux images
+ *                1 indicates that the dcss should be exclusive for this linux image
+ * addr         : will be filled with start address of the segment
+ * end          : will be filled with end address of the segment
+ * return values:
+ * -ENOSYS  : we are not running on VM
+ * -EIO     : could not perform query or load diagnose
+ * -ENOENT  : no such segment
+ * -ENOTSUPP: multi-part segment cannot be used with linux
+ * -ENOSPC  : segment cannot be used (overlaps with storage)
+ * -EBUSY   : segment can temporarily not be used (overlaps with dcss)
+ * -ERANGE  : segment cannot be used (exceeds kernel mapping range)
+ * -EPERM   : segment is currently loaded with incompatible permissions
+ * -ENOMEM  : out of memory
+ * 0 .. 6   : type of segment as defined in include/asm-s390/extmem.h
  */
-int segment_load(char *name, int segtype, unsigned long *addr,
-                 unsigned long *end)
+int
+segment_load (char *name, int do_nonshared, unsigned long *addr,
+               unsigned long *end)
 {
-        char dcss_name[8];
-        struct list_head *l;
-        struct dcss_segment *seg, *tmp;
-       unsigned long dummy;
-       unsigned long segstart, segend;
-        int rc = 0,i;
-        int rwattr, shattr;
-
-        if (!MACHINE_IS_VM)
-                return -ENOSYS;
-        dcss_mkname(name, dcss_name);
-       /* search for the dcss in list of currently loaded segments */
-        spin_lock(&dcss_lock);
-        seg = NULL;
-        list_for_each(l, &dcss_list) {
-                tmp = list_entry(l, struct dcss_segment, list);
-                if (memcmp(tmp->dcss_name, dcss_name, 8) == 0) {
-                        seg = tmp;
-                        break;
-                }
-        }
-
-        if (seg == NULL) {
-                /* find out the attributes of this
-                   shared segment */
-                dcss_diag_query(dcss_name, &rwattr, &shattr, &segstart, &segend);
-               /* does segment collide with main memory? */
-               for (i=0; i < MEMORY_CHUNKS; i++) {
-                       if (memory_chunk[i].type != 0)
-                               continue;
-                       if (memory_chunk[i].addr > segend)
-                               continue;
-                       if (memory_chunk[i].addr + memory_chunk[i].size <= segstart)
-                               continue;
-                       spin_unlock(&dcss_lock);
-                       return -ENOENT;
-               }
-               /* or does it collide with other (loaded) segments? */
-               list_for_each(l, &dcss_list) {
-                       tmp = list_entry(l, struct dcss_segment, list);
-                       if ((segstart <= tmp->end && segstart >= tmp->start_addr) ||
-                               (segend <= tmp->end && segend >= tmp->start_addr) ||
-                               (segstart <= tmp->start_addr && segend >= tmp->end)) {
-                               PRINT_ERR("Segment Overlap!\n");
-                               spin_unlock(&dcss_lock);
-                               return -ENOENT;
-                       }
-               }
-
-                /* do case statement on segtype */
-                /* if asking for shared ro,
-                   shared rw works */
-                /* if asking for exclusive ro,
-                   exclusive rw works */
-
-                switch(segtype) {
-                case SEGMENT_SHARED_RO:
-                        if (shattr > 1 || rwattr > 1) {
-                                spin_unlock(&dcss_lock);
-                                return -ENOENT;
-                        } else {
-                                if (shattr == 0 && rwattr == 0)
-                                        rc = SEGMENT_EXCLUSIVE_RO;
-                                if (shattr == 0 && rwattr == 1)
-                                        rc = SEGMENT_EXCLUSIVE_RW;
-                                if (shattr == 1 && rwattr == 0)
-                                        rc = SEGMENT_SHARED_RO;
-                                if (shattr == 1 && rwattr == 1)
-                                        rc = SEGMENT_SHARED_RW;
-                        }
-                        break;
-                case SEGMENT_SHARED_RW:
-                        if (shattr > 1 || rwattr != 1) {
-                                spin_unlock(&dcss_lock);
-                                return -ENOENT;
-                        } else {
-                                if (shattr == 0)
-                                        rc = SEGMENT_EXCLUSIVE_RW;
-                                if (shattr == 1)
-                                        rc = SEGMENT_SHARED_RW;
-                        }
-                        break;
-
-                case SEGMENT_EXCLUSIVE_RO:
-                        if (shattr > 0 || rwattr > 1) {
-                                spin_unlock(&dcss_lock);
-                                return -ENOENT;
-                        } else {
-                                if (rwattr == 0)
-                                        rc = SEGMENT_EXCLUSIVE_RO;
-                                if (rwattr == 1)
-                                        rc = SEGMENT_EXCLUSIVE_RW;
-                        }
-                        break;
-
-                case SEGMENT_EXCLUSIVE_RW:
-/*                        if (shattr != 0 || rwattr != 1) {
-                                spin_unlock(&dcss_lock);
-                                return -ENOENT;
-                        } else {
-*/
-                                rc = SEGMENT_EXCLUSIVE_RW;
-//                        }
-                        break;
-
-                default:
-                        spin_unlock(&dcss_lock);
-                        return -ENOENT;
-                } /* end switch */
-
-                seg = kmalloc(sizeof(struct dcss_segment), GFP_DMA);
-                if (seg != NULL) {
-                        memcpy(seg->dcss_name, dcss_name, 8);
-                       if (rc == SEGMENT_EXCLUSIVE_RW) {
-                               if (dcss_diag(DCSS_LOADNSR, seg->dcss_name,
-                                               &seg->start_addr, &seg->end) == 0) {
-                                       if (seg->end < max_low_pfn*PAGE_SIZE ) {
-                                               atomic_set(&seg->ref_count, 1);
-                                               list_add(&seg->list, &dcss_list);
-                                               *addr = seg->start_addr;
-                                               *end = seg->end;
-                                               seg->dcss_attr = rc;
-                                               if (shattr == 1 && rwattr == 1)
-                                                       seg->shared_attr = SEGMENT_SHARED_RW;
-                                               else if (shattr == 1 && rwattr == 0)
-                                                       seg->shared_attr = SEGMENT_SHARED_RO;
-                                               else
-                                                       seg->shared_attr = SEGMENT_EXCLUSIVE_RW;
-                                       } else {
-                                               dcss_diag(DCSS_PURGESEG, seg->dcss_name, &dummy, &dummy);
-                                               kfree (seg);
-                                               rc = -ENOENT;
-                                       }
-                               } else {
-                                       kfree(seg);
-                                       rc = -ENOENT;
-                               }
-                               goto out;
-                        }
-                       if (dcss_diag(DCSS_LOADNOLY, seg->dcss_name,
-                                      &seg->start_addr, &seg->end) == 0) {
-                               if (seg->end < max_low_pfn*PAGE_SIZE ) {
-                                       atomic_set(&seg->ref_count, 1);
-                                       list_add(&seg->list, &dcss_list);
-                                       *addr = seg->start_addr;
-                                       *end = seg->end;
-                                       seg->dcss_attr = rc;
-                                       seg->shared_attr = rc;
-                               } else {
-                                       dcss_diag(DCSS_PURGESEG, seg->dcss_name, &dummy, &dummy);
-                                       kfree (seg);
-                                       rc = -ENOENT;
-                               }
-                        } else {
-                                kfree(seg);
-                                rc = -ENOENT;
-                        }
-                } else rc = -ENOMEM;
-        } else {
-               /* found */
-               if ((segtype == SEGMENT_EXCLUSIVE_RW) && (seg->dcss_attr != SEGMENT_EXCLUSIVE_RW)) {
-                       PRINT_ERR("Segment already loaded in other mode than EXCLUSIVE_RW!\n");
-                       rc = -EPERM;
-                       goto out;
-                       /* reload segment in exclusive mode */
-/*                     dcss_diag(DCSS_LOADNSR, seg->dcss_name,
-                                 &seg->start_addr, &seg->end);
-                       seg->dcss_attr = SEGMENT_EXCLUSIVE_RW;*/
+       struct dcss_segment *seg;
+       int rc;
+
+       if (!MACHINE_IS_VM)
+               return -ENOSYS;
+
+       spin_lock (&dcss_lock);
+       seg = segment_by_name (name);
+       if (seg == NULL)
+               rc = __segment_load (name, do_nonshared, addr, end);
+       else {
+               if (do_nonshared == seg->do_nonshared) {
+                       atomic_inc(&seg->ref_count);
+                       *addr = seg->start_addr;
+                       *end  = seg->end;
+                       rc    = seg->vm_segtype;
+               } else {
+                       *addr = *end = 0;
+                       rc    = -EPERM;
                }
-               if ((segtype != SEGMENT_EXCLUSIVE_RW) && (seg->dcss_attr == SEGMENT_EXCLUSIVE_RW)) {
-                       PRINT_ERR("Segment already loaded in EXCLUSIVE_RW mode!\n");
-                       rc = -EPERM;
-                       goto out;
-               }
-                atomic_inc(&seg->ref_count);
-                *addr = seg->start_addr;
-                *end = seg->end;
-                rc = seg->dcss_attr;
-        }
-out:
-        spin_unlock(&dcss_lock);
-        return rc;
+       }
+       spin_unlock (&dcss_lock);
+       return rc;
+}
+
+/*
+ * this function modifies the shared state of a DCSS segment. note that
+ * name         : name of the DCSS
+ * do_nonshared : 0 indicates that the dcss should be shared with other linux images
+ *                1 indicates that the dcss should be exclusive for this linux image
+ * return values:
+ * -EIO     : could not perform load diagnose (segment gone!)
+ * -ENOENT  : no such segment (segment gone!)
+ * -EAGAIN  : segment is in use by other exploiters, try later
+ * -EINVAL  : no segment with the given name is currently loaded - name invalid
+ * 0       : operation succeeded
+ */
+int
+segment_modify_shared (char *name, int do_nonshared)
+{
+       struct dcss_segment *seg;
+       unsigned long dummy;
+       int dcss_command, rc, diag_cc;
+
+       spin_lock (&dcss_lock);
+       seg = segment_by_name (name);
+       if (seg == NULL) {
+               rc = -EINVAL;
+               goto out_unlock;
+       }
+       if (do_nonshared == seg->do_nonshared) {
+               PRINT_INFO ("segment_modify_shared: not reloading segment %s"
+                               " - already in requested mode\n",name);
+               rc = 0;
+               goto out_unlock;
+       }
+       if (atomic_read (&seg->ref_count) != 1) {
+               PRINT_WARN ("segment_modify_shared: not reloading segment %s - "
+                               "segment is in use by other driver(s)\n",name);
+               rc = -EAGAIN;
+               goto out_unlock;
+       }
+       dcss_diag(DCSS_PURGESEG, seg->dcss_name,
+                 &dummy, &dummy);
+       if (do_nonshared)
+               dcss_command = DCSS_LOADNSR;
+       else
+       dcss_command = DCSS_LOADNOLY;
+       diag_cc = dcss_diag(dcss_command, seg->dcss_name,
+                       &seg->start_addr, &seg->end);
+       if (diag_cc > 1) {
+               PRINT_WARN ("segment_modify_shared: could not reload segment %s"
+                               " - diag returned error (%ld)\n",name,seg->end);
+               rc = dcss_diag_translate_rc (seg->end);
+               goto out_del;
+       }
+       seg->do_nonshared = do_nonshared;
+       rc = 0;
+       goto out_unlock;
+ out_del:
+       list_del(&seg->list);
+       dcss_diag(DCSS_PURGESEG, seg->dcss_name,
+                 &dummy, &dummy);
+       kfree (seg);
+ out_unlock:
+       spin_unlock(&dcss_lock);
+       return rc;
 }
 
 /*
@@ -422,84 +516,73 @@ out:
  * it from the address space if nobody is using it
  * any longer.
  */
-void segment_unload(char *name)
+void
+segment_unload(char *name)
 {
-        char dcss_name[8];
-        unsigned long dummy;
-        struct list_head *l,*l_tmp;
-        struct dcss_segment *seg;
-
-        if (!MACHINE_IS_VM)
-                return;
-        dcss_mkname(name, dcss_name);
-        spin_lock(&dcss_lock);
-        list_for_each_safe(l, l_tmp, &dcss_list) {
-                seg = list_entry(l, struct dcss_segment, list);
-                if (memcmp(seg->dcss_name, dcss_name, 8) == 0) {
-                        if (atomic_dec_return(&seg->ref_count) == 0) {
-                                /* Last user of the segment is
-                                   gone. */
-                                list_del(&seg->list);
-                                dcss_diag(DCSS_PURGESEG, seg->dcss_name,
-                                          &dummy, &dummy);
-                               kfree(seg);
-                        }
-                        break;
-                }
-        }
-        spin_unlock(&dcss_lock);
+       unsigned long dummy;
+       struct dcss_segment *seg;
+
+       if (!MACHINE_IS_VM)
+               return;
+
+       spin_lock(&dcss_lock);
+       seg = segment_by_name (name);
+       if (seg == NULL) {
+               PRINT_ERR ("could not find segment %s in segment_unload, "
+                               "please report to linux390@de.ibm.com\n",name);
+               goto out_unlock;
+       }
+       if (atomic_dec_return(&seg->ref_count) == 0) {
+               list_del(&seg->list);
+               dcss_diag(DCSS_PURGESEG, seg->dcss_name,
+                         &dummy, &dummy);
+               kfree(seg);
+       }
+out_unlock:
+       spin_unlock(&dcss_lock);
 }
 
 /*
- * Replace an existing DCSS segment, so that machines
- * that load it anew will see the new version.
+ * save segment content permanently
  */
-void segment_replace(char *name)
+void
+segment_save(char *name)
 {
-        char dcss_name[8];
-        struct list_head *l;
-        struct dcss_segment *seg;
-        int mybeg = 0;
-        int myend = 0;
-        char mybuff1[80];
-        char mybuff2[80];
-
-        if (!MACHINE_IS_VM)
-                return;
-        dcss_mkname(name, dcss_name);
-
-        memset (mybuff1, 0, sizeof(mybuff1));
-        memset (mybuff2, 0, sizeof(mybuff2));
-
-        spin_lock(&dcss_lock);
-        list_for_each(l, &dcss_list) {
-                seg = list_entry(l, struct dcss_segment, list);
-                if (memcmp(seg->dcss_name, dcss_name, 8) == 0) {
-                        mybeg = seg->start_addr >> 12;
-                        myend = (seg->end) >> 12;
-                        if (seg->shared_attr == SEGMENT_EXCLUSIVE_RW)
-                                sprintf(mybuff1, "DEFSEG %s %X-%X EW",
-                                        name, mybeg, myend);
-                        if (seg->shared_attr == SEGMENT_EXCLUSIVE_RO)
-                                sprintf(mybuff1, "DEFSEG %s %X-%X RO",
-                                        name, mybeg, myend);
-                        if (seg->shared_attr == SEGMENT_SHARED_RW)
-                                sprintf(mybuff1, "DEFSEG %s %X-%X SW",
-                                        name, mybeg, myend);
-                        if (seg->shared_attr == SEGMENT_SHARED_RO)
-                                sprintf(mybuff1, "DEFSEG %s %X-%X SR",
-                                        name, mybeg, myend);
-                        spin_unlock(&dcss_lock);
-                        sprintf(mybuff2, "SAVESEG %s", name);
-                        cpcmd(mybuff1, NULL, 80);
-                        cpcmd(mybuff2, NULL, 80);
-                        break;
-                }
-
-        }
-        if (myend == 0) spin_unlock(&dcss_lock);
+       struct dcss_segment *seg;
+       int startpfn = 0;
+       int endpfn = 0;
+       char cmd1[160];
+       char cmd2[80];
+       int i;
+
+       if (!MACHINE_IS_VM)
+               return;
+
+       spin_lock(&dcss_lock);
+       seg = segment_by_name (name);
+
+       if (seg == NULL) {
+               PRINT_ERR ("could not find segment %s in segment_save, please report to linux390@de.ibm.com\n",name);
+               return;
+       }
+
+       startpfn = seg->start_addr >> PAGE_SHIFT;
+       endpfn = (seg->end) >> PAGE_SHIFT;
+       sprintf(cmd1, "DEFSEG %s", name);
+       for (i=0; i<seg->segcnt; i++) {
+               sprintf(cmd1+strlen(cmd1), " %X-%X %s",
+                       seg->range[i].start >> PAGE_SHIFT,
+                       seg->range[i].end >> PAGE_SHIFT,
+                       segtype_string[seg->range[i].start & 0xff]);
+       }
+       sprintf(cmd2, "SAVESEG %s", name);
+       cpcmd(cmd1, NULL, 0);
+       cpcmd(cmd2, NULL, 0);
+       spin_unlock(&dcss_lock);
 }
 
 EXPORT_SYMBOL(segment_load);
 EXPORT_SYMBOL(segment_unload);
-EXPORT_SYMBOL(segment_replace);
+EXPORT_SYMBOL(segment_save);
+EXPORT_SYMBOL(segment_type);
+EXPORT_SYMBOL(segment_modify_shared);