/*
* 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>
* (C) IBM Corporation 2002-2004
*/
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/bootmem.h>
#include <asm/page.h>
#include <asm/ebcdic.h>
#include <asm/errno.h>
#include <asm/extmem.h>
#include <asm/cpcmd.h>
#include <linux/ctype.h>
#define DCSS_DEBUG /* Debug messages on/off */
#define DCSS_NAME "extmem"
#ifdef DCSS_DEBUG
#define PRINT_DEBUG(x...) printk(KERN_DEBUG DCSS_NAME " debug:" x)
#else
#define PRINT_DEBUG(x...) do {} while (0)
#endif
#define PRINT_INFO(x...) printk(KERN_INFO DCSS_NAME " info:" x)
#define PRINT_WARN(x...) printk(KERN_WARNING DCSS_NAME " warning:" x)
#define PRINT_ERR(x...) printk(KERN_ERR DCSS_NAME " error:" x)
#define DCSS_LOADSHR 0x00
#define DCSS_LOADNSR 0x04
#define DCSS_PURGESEG 0x08
#define DCSS_FINDSEG 0x0c
#define DCSS_LOADNOLY 0x10
#define DCSS_SEGEXT 0x18
#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 do_nonshared;
unsigned int vm_segtype;
struct qrange range[6];
int segcnt;
};
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];
/*
* Create the 8 bytes, ebcdic VM segment name from
* an ascii 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)
{
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.
*/
static inline int
dcss_diag (__u8 func, void *parameter,
unsigned long *ret1, unsigned long *ret2)
{
unsigned long rx, ry;
int rc;
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
#else
" 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;
}
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;
}
/*
* 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
* -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;
}
/*
* 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 do_nonshared, unsigned long *addr,
unsigned long *end)
{
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;
}
}
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;
}
/*
* Decrease the use count of a DCSS segment and remove
* it from the address space if nobody is using it
* any longer.
*/
void
segment_unload(char *name)
{
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);
}
/*
* save segment content permanently
*/
void
segment_save(char *name)
{
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, NULL);
cpcmd(cmd2, NULL, 0, NULL);
spin_unlock(&dcss_lock);
}
EXPORT_SYMBOL(segment_load);
EXPORT_SYMBOL(segment_unload);
EXPORT_SYMBOL(segment_save);
EXPORT_SYMBOL(segment_type);
EXPORT_SYMBOL(segment_modify_shared);
