[patch 3/6] s390: dcss segments.
From: Carsten Otte <[email protected]>
dcss segment interface changes:
- Add check when loading segments to avoid out of range mappings.
- Add code to check for segment_load returning -ERANGE.
- Rename segment_info to segment_type.
- Restore previous segment state if reload fails.
- Add segment_modify_shared() to change shared attributes of a dcss
segment and use it in the dcss block device driver.
- Add support for contiguous EW/EN multipart segments.
Signed-off-by: Martin Schwidefsky <[email protected]>
diffstat:
arch/s390/mm/extmem.c | 159 +++++++++++++++++++++++++++++++++++++-----
drivers/s390/block/dcssblk.c | 69 ++++++++----------
drivers/s390/char/monreader.c | 8 +-
include/asm-s390/extmem.h | 4 -
4 files changed, 183 insertions(+), 57 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 2004-11-30 14:03:01.000000000 +0100
+++ linux-2.6-patched/arch/s390/mm/extmem.c 2004-11-30 14:03:19.000000000 +0100
@@ -40,14 +40,19 @@
#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;
- char segout[8][6];
+ struct qrange range[6];
};
struct qin64 {
@@ -67,12 +72,15 @@
unsigned long end;
atomic_t ref_count;
int do_nonshared;
- int vm_segtype;
+ unsigned int vm_segtype;
+ struct qrange range[6];
+ int segcnt;
};
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" };
+static char *segtype_string[] = { "SW", "EW", "SR", "ER", "SN", "EN", "SC",
+ "EW/EN-MIXED" };
extern struct {
unsigned long addr, size, type;
@@ -162,12 +170,12 @@
* fills start_address, end and vm_segtype fields
*/
static int
-query_segment_info (struct dcss_segment *seg)
+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;
+ int diag_cc, rc, i;
unsigned long dummy, vmrc;
if ((qin == NULL) || (qout == NULL)) {
@@ -176,7 +184,7 @@
}
/* initialize diag input parameters */
- qin->qopcode = DCSS_QACTV;
+ qin->qopcode = DCSS_FINDSEGA;
qin->qoutptr = (unsigned long) qout;
qin->qoutlen = sizeof(struct qout64);
memcpy (qin->qname, seg->dcss_name, 8);
@@ -188,16 +196,40 @@
goto out_free;
}
- if (qout->segcnt > 1) {
+ 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;
- seg->vm_segtype = qout->segout[0][3];
+ memcpy (seg->range, qout->range, 6*sizeof(struct qrange));
+ seg->segcnt = qout->segcnt;
rc = 0;
@@ -254,6 +286,19 @@
}
/*
+ * 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
+segment_exceeds_range (struct dcss_segment *seg)
+{
+ 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
@@ -265,7 +310,7 @@
* 0 .. 6 : type of segment as defined in include/asm-s390/extmem.h
*/
int
-segment_info (char* name)
+segment_type (char* name)
{
int rc;
struct dcss_segment seg;
@@ -274,7 +319,7 @@
return -ENOSYS;
dcss_mkname(name, seg.dcss_name);
- rc = query_segment_info (&seg);
+ rc = query_segment_type (&seg);
if (rc < 0)
return rc;
return seg.vm_segtype;
@@ -295,9 +340,15 @@
goto out;
}
dcss_mkname (name, seg->dcss_name);
- rc = query_segment_info (seg);
+ 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);
@@ -362,6 +413,7 @@
* -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
@@ -396,6 +448,70 @@
}
/*
+ * 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;
+}
+
+/*
* Decrease the use count of a DCSS segment and remove
* it from the address space if nobody is using it
* any longer.
@@ -434,8 +550,9 @@
struct dcss_segment *seg;
int startpfn = 0;
int endpfn = 0;
- char cmd1[80];
+ char cmd1[160];
char cmd2[80];
+ int i;
if (!MACHINE_IS_VM)
return;
@@ -448,10 +565,15 @@
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]);
+ 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, 80);
cpcmd(cmd2, NULL, 80);
@@ -461,4 +583,5 @@
EXPORT_SYMBOL(segment_load);
EXPORT_SYMBOL(segment_unload);
EXPORT_SYMBOL(segment_save);
-EXPORT_SYMBOL(segment_info);
+EXPORT_SYMBOL(segment_type);
+EXPORT_SYMBOL(segment_modify_shared);
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 2004-11-30 14:03:04.000000000 +0100
+++ linux-2.6-patched/drivers/s390/block/dcssblk.c 2004-11-30 14:03:19.000000000 +0100
@@ -140,7 +140,7 @@
}
/*
- * print appropriate error message for segment_load()/segment_info()
+ * print appropriate error message for segment_load()/segment_type()
* return code
*/
static void
@@ -179,6 +179,10 @@
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);
@@ -214,57 +218,50 @@
if (atomic_read(&dev_info->use_count)) {
PRINT_ERR("share: segment %s is busy!\n",
dev_info->segment_name);
- up_write(&dcssblk_devices_sem);
- return -EBUSY;
- }
- if ((inbuf[0] == '1') && (dev_info->is_shared == 1)) {
- PRINT_WARN("Segment %s already loaded in shared mode!\n",
- dev_info->segment_name);
- up_write(&dcssblk_devices_sem);
- return count;
- }
- if ((inbuf[0] == '0') && (dev_info->is_shared == 0)) {
- PRINT_WARN("Segment %s already loaded in exclusive mode!\n",
- dev_info->segment_name);
- up_write(&dcssblk_devices_sem);
- return count;
+ rc = -EBUSY;
+ goto out;
}
if (inbuf[0] == '1') {
// reload segment in shared mode
- segment_unload(dev_info->segment_name);
- rc = segment_load(dev_info->segment_name, SEGMENT_SHARED,
- &dev_info->start, &dev_info->end);
+ rc = segment_modify_shared(dev_info->segment_name,
+ SEGMENT_SHARED);
if (rc < 0) {
- dcssblk_segment_warn(rc, dev_info->segment_name);
- goto removeseg;
+ BUG_ON(rc == -EINVAL);
+ if (rc == -EIO || rc == -ENOENT)
+ 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);
+ }
}
- dev_info->is_shared = 1;
- 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;
+ rc = -EINVAL;
+ goto out;
}
- segment_unload(dev_info->segment_name);
- rc = segment_load(dev_info->segment_name, SEGMENT_EXCLUSIVE,
- &dev_info->start, &dev_info->end);
+ rc = segment_modify_shared(dev_info->segment_name,
+ SEGMENT_EXCLUSIVE);
if (rc < 0) {
- dcssblk_segment_warn(rc, dev_info->segment_name);
- goto removeseg;
+ BUG_ON(rc == -EINVAL);
+ if (rc == -EIO || rc == -ENOENT)
+ goto removeseg;
+ } else {
+ dev_info->is_shared = 0;
+ set_disk_ro(dev_info->gd, 0);
}
- dev_info->is_shared = 0;
- 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;
+ rc = -EINVAL;
+ goto out;
}
rc = count;
- up_write(&dcssblk_devices_sem);
goto out;
removeseg:
@@ -278,8 +275,8 @@
put_disk(dev_info->gd);
device_unregister(dev);
put_device(dev);
- up_write(&dcssblk_devices_sem);
out:
+ up_write(&dcssblk_devices_sem);
return rc;
}
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 2004-11-30 14:03:04.000000000 +0100
+++ linux-2.6-patched/drivers/s390/char/monreader.c 2004-11-30 14:03:19.000000000 +0100
@@ -116,7 +116,7 @@
}
/*
- * print appropriate error message for segment_load()/segment_info()
+ * print appropriate error message for segment_load()/segment_type()
* return code
*/
static void
@@ -155,6 +155,10 @@
P_WARNING("cannot load/query segment %s, out of memory\n",
seg_name);
break;
+ case -ERANGE:
+ P_WARNING("cannot load/query segment %s, exceeds kernel "
+ "mapping range\n", seg_name);
+ break;
default:
P_WARNING("cannot load/query segment %s, return value %i\n",
seg_name, rc);
@@ -581,7 +585,7 @@
return -ENODEV;
}
- rc = segment_info(mon_dcss_name);
+ rc = segment_type(mon_dcss_name);
if (rc < 0) {
mon_segment_warn(rc, mon_dcss_name);
return rc;
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 2004-11-30 14:03:08.000000000 +0100
+++ linux-2.6-patched/include/asm-s390/extmem.h 2004-11-30 14:03:19.000000000 +0100
@@ -17,6 +17,7 @@
#define SEG_TYPE_SN 4
#define SEG_TYPE_EN 5
#define SEG_TYPE_SC 6
+#define SEG_TYPE_EWEN 7
#define SEGMENT_SHARED 0
#define SEGMENT_EXCLUSIVE 1
@@ -24,7 +25,8 @@
extern int segment_load (char *name,int segtype,unsigned long *addr,unsigned long *length);
extern void segment_unload(char *name);
extern void segment_save(char *name);
-extern int segment_info (char* name);
+extern int segment_type (char* name);
+extern int segment_modify_shared (char *name, int do_nonshared);
#endif
#endif