[patch 3/6] s390: dcss segments cleanup.

From: Martin Schwidefsky (schwidefsky_at_de.ibm.com)
Date: 10/22/04

  • Next message: Martin Schwidefsky: "[patch 5/6] s390: qdio changes."
    Date:	Fri, 22 Oct 2004 14:25:36 +0200
    To: akpm@osdl.org, linux-kernel@vger.kernel.org
    
    

    [patch 3/6] s390: dcss segments cleanup.

    From: Carsten Otte <cotte@de.ibm.com>
    From: Gerald Schaefer <geraldsc@de.ibm.com>

    Cleanup segment load/unload infrastructure.

    Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

    diffstat:
     arch/s390/mm/extmem.c | 783 +++++++++++++++++++-----------------------
     drivers/s390/block/dcssblk.c | 119 +++---
     drivers/s390/char/monreader.c | 62 +++
     include/asm-s390/extmem.h | 21 -
     4 files changed, 518 insertions(+), 467 deletions(-)

    diff -urN linux-2.6/arch/s390/mm/extmem.c linux-2.6-patched/arch/s390/mm/extmem.c
    --- linux-2.6/arch/s390/mm/extmem.c 2004-10-18 23:54:40.000000000 +0200
    +++ linux-2.6-patched/arch/s390/mm/extmem.c 2004-10-22 13:51:44.000000000 +0200
    @@ -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>
    @@ -43,18 +42,38 @@
     #define DCSS_SEGEXT 0x18
     #define DCSS_QACTV 0x0c
     
    +struct qout64 {
    + int segstart;
    + int segend;
    + int segcnt;
    + int segrcnt;
    + char segout[8][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;
    + int vm_segtype;
     };
     
     static spinlock_t dcss_lock = SPIN_LOCK_UNLOCKED;
     static struct list_head dcss_list = LIST_HEAD_INIT(dcss_list);
    +static char *segtype_string[7] = { "SW", "EW", "SR", "ER", "SN", "EN", "SC" };
    +
     extern struct {
             unsigned long addr, size, type;
     } memory_chunk[MEMORY_CHUNKS];
    @@ -63,20 +82,46 @@
      * 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;
    + 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);
    + 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)
    +{
    + char dcss_name[9];
    + struct list_head *l;
    + struct dcss_segment *tmp, *retval = NULL;
    +
    + BUG_ON (!spin_is_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 +129,270 @@
     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;
     }
     
    -
    -/* use to issue "extended" dcss query */
     static inline int
    -dcss_diag_query(char *name, int *rwattr, int *shattr, unsigned long *segstart, unsigned long *segend)
    +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_info (struct dcss_segment *seg)
     {
    - int i,j,rc;
    - unsigned long rx, ry;
    + struct qin64 *qin = kmalloc (sizeof(struct qin64), GFP_DMA);
    + struct qout64 *qout = kmalloc (sizeof(struct qout64), GFP_DMA);
     
    - 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 */
    + int diag_cc, rc;
    + unsigned long dummy, vmrc;
     
    - /* 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);
    + if ((qin == NULL) || (qout == NULL)) {
    + rc = -ENOMEM;
    + goto out_free;
    + }
    +
    + /* initialize diag input parameters */
    + qin->qopcode = DCSS_QACTV;
    + 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 > 1) {
    + rc = -ENOTSUPP;
    + goto out_free;
    + }
    +
    + /* analyze diag output and update seg */
    + seg->start_addr = qout->segstart;
    + seg->end = qout->segend;
    +
    + seg->vm_segtype = qout->segout[0][3];
    +
    + 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;
    +
    + BUG_ON (!spin_is_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;
    +}
    +
    +/*
    + * 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_info (char* name)
    +{
    + int rc;
    + struct dcss_segment seg;
    +
    + if (!MACHINE_IS_VM)
    + return -ENOSYS;
    +
    + dcss_mkname(name, seg.dcss_name);
    + rc = query_segment_info (&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_info (seg);
    + if (rc < 0)
    + 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)
    + * -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;*/
    - }
    - 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;
    + 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;
                     }
    - 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;
     }
     
     /*
    @@ -422,84 +400,65 @@
      * 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);
    -}
    -
    -/*
    - * Replace an existing DCSS segment, so that machines
    - * that load it anew will see the new version.
    - */
    -void segment_replace(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;
    - }
    + 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);
    +}
     
    - }
    - if (myend == 0) spin_unlock(&dcss_lock);
    +/*
    + * save segment content permanently
    + */
    +void segment_save(char *name)
    +{
    + struct dcss_segment *seg;
    + int startpfn = 0;
    + int endpfn = 0;
    + char cmd1[80];
    + char cmd2[80];
    +
    + 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 >> 12;
    + endpfn = (seg->end) >> 12;
    + sprintf(cmd1, "DEFSEG %s %X-%X %s", name, startpfn, endpfn,
    + segtype_string[seg->vm_segtype]);
    + sprintf(cmd2, "SAVESEG %s", name);
    + cpcmd(cmd1, NULL, 80);
    + cpcmd(cmd2, NULL, 80);
    + spin_unlock(&dcss_lock);
     }
     
     EXPORT_SYMBOL(segment_load);
     EXPORT_SYMBOL(segment_unload);
    -EXPORT_SYMBOL(segment_replace);
    +EXPORT_SYMBOL(segment_save);
    +EXPORT_SYMBOL(segment_info);
    diff -urN linux-2.6/drivers/s390/block/dcssblk.c linux-2.6-patched/drivers/s390/block/dcssblk.c
    --- linux-2.6/drivers/s390/block/dcssblk.c 2004-10-18 23:53:43.000000000 +0200
    +++ linux-2.6-patched/drivers/s390/block/dcssblk.c 2004-10-22 13:51:44.000000000 +0200
    @@ -140,6 +140,53 @@
     }
     
     /*
    + * print appropriate error message for segment_load()/segment_info()
    + * return code
    + */
    +static void
    +dcssblk_segment_warn(int rc, char* seg_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;
    + default:
    + PRINT_WARN("cannot load/query segment %s, return value %i\n",
    + seg_name, rc);
    + break;
    + }
    +}
    +
    +/*
      * device attribute for switching shared/nonshared (exclusive)
      * operation (show + store)
      */
    @@ -185,61 +232,38 @@
             if (inbuf[0] == '1') {
                     // reload segment in shared mode
                     segment_unload(dev_info->segment_name);
    - rc = segment_load(dev_info->segment_name, SEGMENT_SHARED_RO,
    + rc = segment_load(dev_info->segment_name, SEGMENT_SHARED,
                                             &dev_info->start, &dev_info->end);
                     if (rc < 0) {
    - PRINT_ERR("Segment %s not reloaded, rc=%d\n",
    - dev_info->segment_name, rc);
    + dcssblk_segment_warn(rc, dev_info->segment_name);
                             goto removeseg;
                     }
                     dev_info->is_shared = 1;
    - PRINT_INFO("Segment %s reloaded, shared mode.\n",
    - dev_info->segment_name);
    + if (rc == SEG_TYPE_SR || rc == SEG_TYPE_ER || rc == 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);
    + up_write(&dcssblk_devices_sem);
    + return -EINVAL;
    + }
                     segment_unload(dev_info->segment_name);
    - rc = segment_load(dev_info->segment_name, SEGMENT_EXCLUSIVE_RW,
    + rc = segment_load(dev_info->segment_name, SEGMENT_EXCLUSIVE,
                                             &dev_info->start, &dev_info->end);
                     if (rc < 0) {
    - PRINT_ERR("Segment %s not reloaded, rc=%d\n",
    - dev_info->segment_name, rc);
    + dcssblk_segment_warn(rc, dev_info->segment_name);
                             goto removeseg;
                     }
                     dev_info->is_shared = 0;
    - PRINT_INFO("Segment %s reloaded, exclusive (read-write) mode.\n",
    - dev_info->segment_name);
    + set_disk_ro(dev_info->gd, 0);
             } else {
                     up_write(&dcssblk_devices_sem);
                     PRINT_WARN("Invalid value, must be 0 or 1\n");
                     return -EINVAL;
             }
    - dev_info->segment_type = rc;
             rc = count;
    -
    - switch (dev_info->segment_type) {
    - case SEGMENT_SHARED_RO:
    - case SEGMENT_EXCLUSIVE_RO:
    - set_disk_ro(dev_info->gd, 1);
    - break;
    - case SEGMENT_SHARED_RW:
    - case SEGMENT_EXCLUSIVE_RW:
    - set_disk_ro(dev_info->gd, 0);
    - break;
    - }
    - if ((inbuf[0] == '1') &&
    - ((dev_info->segment_type == SEGMENT_EXCLUSIVE_RO) ||
    - (dev_info->segment_type == SEGMENT_EXCLUSIVE_RW))) {
    - PRINT_WARN("Could not get shared copy of segment %s\n",
    - dev_info->segment_name);
    - rc = -EPERM;
    - }
    - if ((inbuf[0] == '0') &&
    - ((dev_info->segment_type == SEGMENT_SHARED_RO) ||
    - (dev_info->segment_type == SEGMENT_SHARED_RW))) {
    - PRINT_WARN("Could not get exclusive copy of segment %s\n",
    - dev_info->segment_name);
    - rc = -EPERM;
    - }
             up_write(&dcssblk_devices_sem);
             goto out;
     
    @@ -292,7 +316,7 @@
                             // device is idle => we save immediately
                             PRINT_INFO("Saving segment %s\n",
                                        dev_info->segment_name);
    - segment_replace(dev_info->segment_name);
    + segment_save(dev_info->segment_name);
                     } else {
                             // device is busy => we save it when it becomes
                             // idle in dcssblk_release
    @@ -390,18 +414,17 @@
             /*
              * load the segment
              */
    - rc = segment_load(local_buf, SEGMENT_SHARED_RO,
    + rc = segment_load(local_buf, SEGMENT_SHARED,
                                     &dev_info->start, &dev_info->end);
             if (rc < 0) {
    - PRINT_ERR("Segment %s not loaded, rc=%d\n", local_buf, rc);
    + dcssblk_segment_warn(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 from %p to %p, size = %lu Byte, "
    - "capacity = %lu sectors (512 Byte)\n", local_buf,
    - (void *) dev_info->start, (void *) dev_info->end,
    - seg_byte_size, seg_byte_size >> 9);
    + 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;
    @@ -451,12 +474,12 @@
             blk_queue_hardsect_size(dev_info->dcssblk_queue, 4096);
     
             switch (dev_info->segment_type) {
    - case SEGMENT_SHARED_RO:
    - case SEGMENT_EXCLUSIVE_RO:
    + case SEG_TYPE_SR:
    + case SEG_TYPE_ER:
    + case SEG_TYPE_SC:
                             set_disk_ro(dev_info->gd,1);
                             break;
    - case SEGMENT_SHARED_RW:
    - case SEGMENT_EXCLUSIVE_RW:
    + default:
                             set_disk_ro(dev_info->gd,0);
                             break;
             }
    @@ -589,7 +612,7 @@
                 && (dev_info->save_pending)) {
                     PRINT_INFO("Segment %s became idle and is being saved now\n",
                                 dev_info->segment_name);
    - segment_replace(dev_info->segment_name);
    + segment_save(dev_info->segment_name);
                     dev_info->save_pending = 0;
             }
             up_write(&dcssblk_devices_sem);
    diff -urN linux-2.6/drivers/s390/char/monreader.c linux-2.6-patched/drivers/s390/char/monreader.c
    --- linux-2.6/drivers/s390/char/monreader.c 2004-10-22 13:51:36.000000000 +0200
    +++ linux-2.6-patched/drivers/s390/char/monreader.c 2004-10-22 13:51:44.000000000 +0200
    @@ -115,6 +115,53 @@
             ASCEBC(ebcdic_name, 8);
     }
     
    +/*
    + * print appropriate error message for segment_load()/segment_info()
    + * return code
    + */
    +static void
    +mon_segment_warn(int rc, char* seg_name)
    +{
    + switch (rc) {
    + case -ENOENT:
    + P_WARNING("cannot load/query segment %s, does not exist\n",
    + seg_name);
    + break;
    + case -ENOSYS:
    + P_WARNING("cannot load/query segment %s, not running on VM\n",
    + seg_name);
    + break;
    + case -EIO:
    + P_WARNING("cannot load/query segment %s, hardware error\n",
    + seg_name);
    + break;
    + case -ENOTSUPP:
    + P_WARNING("cannot load/query segment %s, is a multi-part "
    + "segment\n", seg_name);
    + break;
    + case -ENOSPC:
    + P_WARNING("cannot load/query segment %s, overlaps with "
    + "storage\n", seg_name);
    + break;
    + case -EBUSY:
    + P_WARNING("cannot load/query segment %s, overlaps with "
    + "already loaded dcss\n", seg_name);
    + break;
    + case -EPERM:
    + P_WARNING("cannot load/query segment %s, already loaded in "
    + "incompatible mode\n", seg_name);
    + break;
    + case -ENOMEM:
    + P_WARNING("cannot load/query segment %s, out of memory\n",
    + seg_name);
    + break;
    + default:
    + P_WARNING("cannot load/query segment %s, return value %i\n",
    + seg_name, rc);
    + break;
    + }
    +}
    +
     static inline unsigned long
     mon_mca_start(struct mon_msg *monmsg)
     {
    @@ -534,10 +581,21 @@
                     return -ENODEV;
             }
     
    - rc = segment_load(mon_dcss_name, SEGMENT_SHARED_RO,
    + rc = segment_info(mon_dcss_name);
    + if (rc < 0) {
    + mon_segment_warn(rc, mon_dcss_name);
    + return rc;
    + }
    + if (rc != SEG_TYPE_SC) {
    + P_ERROR("segment %s has unsupported type, should be SC\n",
    + mon_dcss_name);
    + return -EINVAL;
    + }
    +
    + rc = segment_load(mon_dcss_name, SEGMENT_SHARED,
                               &mon_dcss_start, &mon_dcss_end);
             if (rc < 0) {
    - P_ERROR("Segment %s not loaded, rc = %d\n", mon_dcss_name, rc);
    + mon_segment_warn(rc, mon_dcss_name);
                     return -EINVAL;
             }
             dcss_mkname(mon_dcss_name, &user_data_connect[8]);
    diff -urN linux-2.6/include/asm-s390/extmem.h linux-2.6-patched/include/asm-s390/extmem.h
    --- linux-2.6/include/asm-s390/extmem.h 2004-10-18 23:54:39.000000000 +0200
    +++ linux-2.6-patched/include/asm-s390/extmem.h 2004-10-22 13:51:44.000000000 +0200
    @@ -8,12 +8,23 @@
     #ifndef _ASM_S390X_DCSS_H
     #define _ASM_S390X_DCSS_H
     #ifndef __ASSEMBLY__
    -#define SEGMENT_SHARED_RW 0
    -#define SEGMENT_SHARED_RO 1
    -#define SEGMENT_EXCLUSIVE_RW 2
    -#define SEGMENT_EXCLUSIVE_RO 3
    +
    +/* possible values for segment type as returned by segment_info */
    +#define SEG_TYPE_SW 0
    +#define SEG_TYPE_EW 1
    +#define SEG_TYPE_SR 2
    +#define SEG_TYPE_ER 3
    +#define SEG_TYPE_SN 4
    +#define SEG_TYPE_EN 5
    +#define SEG_TYPE_SC 6
    +
    +#define SEGMENT_SHARED 0
    +#define SEGMENT_EXCLUSIVE 1
    +
     extern int segment_load (char *name,int segtype,unsigned long *addr,unsigned long *length);
     extern void segment_unload(char *name);
    -extern void segment_replace(char *name);
    +extern void segment_save(char *name);
    +extern int segment_info (char* name);
    +
     #endif
     #endif
    -
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  • Next message: Martin Schwidefsky: "[patch 5/6] s390: qdio changes."

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