/*
* 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>
* Copyright IBM Corp. 2002, 2004
*/
#define KMSG_COMPONENT "extmem"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#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 <linux/ctype.h>
#include <linux/ioport.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/ebcdic.h>
#include <asm/errno.h>
#include <asm/extmem.h>
#include <asm/cpcmd.h>
#include <asm/setup.h>
#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_LOADSHRX 0x20
#define DCSS_LOADNSRX 0x24
#define DCSS_FINDSEGX 0x2c
#define DCSS_SEGEXTX 0x38
#define DCSS_FINDSEGA 0x0c
struct qrange {
unsigned long start; /* last byte type */
unsigned long end; /* last byte reserved */
};
struct qout64 {
unsigned long segstart;
unsigned long segend;
int segcnt;
int segrcnt;
struct qrange range[6];
};
struct qrange_old {
unsigned int start; /* last byte type */
unsigned int end; /* last byte reserved */
};
/* output area format for the Diag x'64' old subcode x'18' */
struct qout64_old {
int segstart;
int segend;
int segcnt;
int segrcnt;
struct qrange_old 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];
char res_name[15];
unsigned long start_addr;
unsigned long end;
atomic_t ref_count;
int do_nonshared;
unsigned int vm_segtype;
struct qrange range[6];
int segcnt;
struct resource *res;
};
static DEFINE_MUTEX(dcss_lock);
static LIST_HEAD(dcss_list);
static char *segtype_string[] = { "SW", "EW", "SR", "ER", "SN", "EN", "SC",
"EW/EN-MIXED" };
static int loadshr_scode, loadnsr_scode, findseg_scode;
static int segext_scode, purgeseg_scode;
static int scode_set;
/* set correct Diag x'64' subcodes. */
static int
dcss_set_subcodes(void)
{
char *name = kmalloc(8 * sizeof(char), GFP_KERNEL | GFP_DMA);
unsigned long rx, ry;
int rc;
if (name == NULL)
return -ENOMEM;
rx = (unsigned long) name;
ry = DCSS_FINDSEGX;
strcpy(name, "dummy");
asm volatile(
" diag %0,%1,0x64\n"
"0: ipm %2\n"
" srl %2,28\n"
" j 2f\n"
"1: la %2,3\n"
"2:\n"
EX_TABLE(0b, 1b)
: "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
kfree(name);
/* Diag x'64' new subcodes are supported, set to new subcodes */
if (rc != 3) {
loadshr_scode = DCSS_LOADSHRX;
loadnsr_scode = DCSS_LOADNSRX;
purgeseg_scode = DCSS_PURGESEG;
findseg_scode = DCSS_FINDSEGX;
segext_scode = DCSS_SEGEXTX;
return 0;
}
/* Diag x'64' new subcodes are not supported, set to old subcodes */
loadshr_scode = DCSS_LOADNOLY;
loadnsr_scode = DCSS_LOADNSR;
purgeseg_scode = DCSS_PURGESEG;
findseg_scode = DCSS_FINDSEG;
segext_scode = DCSS_SEGEXT;
return 0;
}
/*
* Create the 8 bytes, ebcdic VM segment name from
* an ascii name.
*/
static void
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;
BUG_ON(!mutex_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.
*/
static inline int
dcss_diag(int *func, void *parameter,
unsigned long *ret1, unsigned long *ret2)
{
unsigned long rx, ry;
int rc;
if (scode_set == 0) {
rc = dcss_set_subcodes();
if (rc < 0)
return rc;
scode_set = 1;
}
rx = (unsigned long) parameter;
ry = (unsigned long) *func;
/* 64-bit Diag x'64' new subcode, keep in 64-bit addressing mode */
if (*func > DCSS_SEGEXT)
asm volatile(
" diag %0,%1,0x64\n"
" ipm %2\n"
" srl %2,28\n"
: "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
/* 31-bit Diag x'64' old subcode, switch to 31-bit addressing mode */
else
asm volatile(
" sam31\n"
" diag %0,%1,0x64\n"
" sam64\n"
" 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)
{
unsigned long dummy, vmrc;
int diag_cc, rc, i;
struct qout64 *qout;
struct qin64 *qin;
qin = kmalloc(sizeof(*qin), GFP_KERNEL | GFP_DMA);
qout = kmalloc(sizeof(*qout), GFP_KERNEL | GFP_DMA);
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(&segext_scode, qin, &dummy, &vmrc);
if (diag_cc < 0) {
rc = diag_cc;
goto out_free;
}
if (diag_cc > 1) {
pr_warning("Querying a DCSS type failed with rc=%ld\n", vmrc);
rc = dcss_diag_translate_rc (vmrc);
goto out_free;
}
/* Only old format of output area of Diagnose x'64' is supported,
copy data for the new format. */
if (segext_scode == DCSS_SEGEXT) {
struct qout64_old *qout_old;
qout_old = kzalloc(sizeof(*qout_old), GFP_KERNEL | GFP_DMA);
if (qout_old == NULL) {
rc = -ENOMEM;
goto out_free;
}
memcpy(qout_old, qout, sizeof(struct qout64_old));
qout->segstart = (unsigned long) qout_old->segstart;
qout->segend = (unsigned long) qout_old->segend;
qout->segcnt = qout_old->segcnt;
qout->segrcnt = qout_old->segrcnt;
if (qout->segcnt > 6)
qout->segrcnt = 6;
for (i = 0; i < qout->segrcnt; i++) {
qout->range[i].start =
(unsigned long) qout_old->range[i].start;
qout->range[i].end =
(unsigned long) qout_old->range[i].end;
}
kfree(qout_old);
}
if (qout->segcnt > 6) {
rc = -EOPNOTSUPP;
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 = -EOPNOTSUPP;
goto out_free;
}
if (start != qout->range[i].start >> PAGE_SHIFT) {
rc = -EOPNOTSUPP;
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:
kfree(qin);
kfree(qout);
return rc;
}
/*
* 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
* -EOPNOTSUPP: multi-part segment cannot be used with linux
* -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;
}
/*
* 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(!mutex_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;
}
/*
* real segment loading function, called from segment_load
*/
static int
__segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long *end)
{
unsigned long start_addr, end_addr, dummy;
struct dcss_segment *seg;
int rc, diag_cc;
start_addr = end_addr = 0;
seg = kmalloc(sizeof(*seg), GFP_KERNEL | GFP_DMA);
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 (loadshr_scode == DCSS_LOADSHRX) {
if (segment_overlaps_others(seg)) {
rc = -EBUSY;
goto out_free;
}
}
rc = vmem_add_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
if (rc)
goto out_free;
seg->res = kzalloc(sizeof(struct resource), GFP_KERNEL);
if (seg->res == NULL) {
rc = -ENOMEM;
goto out_shared;
}
seg->res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
seg->res->start = seg->start_addr;
seg->res->end = seg->end;
memcpy(&seg->res_name, seg->dcss_name, 8);
EBCASC(seg->res_name, 8);
seg->res_name[8] = '\0';
strncat(seg->res_name, " (DCSS)", 7);
seg->res->name = seg->res_name;
rc = seg->vm_segtype;
if (rc == SEG_TYPE_SC ||
((rc == SEG_TYPE_SR || rc == SEG_TYPE_ER) && !do_nonshared))
seg->res->flags |= IORESOURCE_READONLY;
if (request_resource(&iomem_resource, seg->res)) {
rc = -EBUSY;
kfree(seg->res);
goto out_shared;
}
if (do_nonshared)
diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
&start_addr, &end_addr);
else
diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
&start_addr, &end_addr);
if (diag_cc < 0) {
dcss_diag(&purgeseg_scode, seg->dcss_name,
&dummy, &dummy);
rc = diag_cc;
goto out_resource;
}
if (diag_cc > 1) {
pr_warning("Loading DCSS %s failed with rc=%ld\n", name,
end_addr);
rc = dcss_diag_translate_rc(end_addr);
dcss_diag(&purgeseg_scode, seg->dcss_name,
&dummy, &dummy);
goto out_resource;
}
seg->start_addr = start_addr;
seg->end = end_addr;
seg->do_nonshared = do_nonshared;
atomic_set(&seg->ref_count, 1);
list_add(&seg->list, &dcss_list);
*addr = seg->start_addr;
*end = seg->end;
if (do_nonshared)
pr_info("DCSS %s of range %p to %p and type %s loaded as "
"exclusive-writable\n", name, (void*) seg->start_addr,
(void*) seg->end, segtype_string[seg->vm_segtype]);
else {
pr_info("DCSS %s of range %p to %p and type %s loaded in "
"shared access mode\n", name, (void*) seg->start_addr,
(void*) seg->end, segtype_string[seg->vm_segtype]);
}
goto out;
out_resource:
release_resource(seg->res);
kfree(seg->res);
out_shared:
vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
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
* -EOPNOTSUPP: 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;
mutex_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;
}
}
mutex_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
* -EBUSY : segment can temporarily not be used (overlaps with dcss)
* 0 : operation succeeded
*/
int
segment_modify_shared (char *name, int do_nonshared)
{
struct dcss_segment *seg;
unsigned long start_addr, end_addr, dummy;
int rc, diag_cc;
start_addr = end_addr = 0;
mutex_lock(&dcss_lock);
seg = segment_by_name (name);
if (seg == NULL) {
rc = -EINVAL;
goto out_unlock;
}
if (do_nonshared == seg->do_nonshared) {
pr_info("DCSS %s is already in the requested access "
"mode\n", name);
rc = 0;
goto out_unlock;
}
if (atomic_read (&seg->ref_count) != 1) {
pr_warning("DCSS %s is in use and cannot be reloaded\n",
name);
rc = -EAGAIN;
goto out_unlock;
}
release_resource(seg->res);
if (do_nonshared)
seg->res->flags &= ~IORESOURCE_READONLY;
else
if (seg->vm_segtype == SEG_TYPE_SR ||
seg->vm_segtype == SEG_TYPE_ER)
seg->res->flags |= IORESOURCE_READONLY;
if (request_resource(&iomem_resource, seg->res)) {
pr_warning("DCSS %s overlaps with used memory resources "
"and cannot be reloaded\n", name);
rc = -EBUSY;
kfree(seg->res);
goto out_del_mem;
}
dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
if (do_nonshared)
diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
&start_addr, &end_addr);
else
diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
&start_addr, &end_addr);
if (diag_cc < 0) {
rc = diag_cc;
goto out_del_res;
}
if (diag_cc > 1) {
pr_warning("Reloading DCSS %s failed with rc=%ld\n", name,
end_addr);
rc = dcss_diag_translate_rc(end_addr);
goto out_del_res;
}
seg->start_addr = start_addr;
seg->end = end_addr;
seg->do_nonshared = do_nonshared;
rc = 0;
goto out_unlock;
out_del_res:
release_resource(seg->res);
kfree(seg->res);
out_del_mem:
vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
list_del(&seg->list);
dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
kfree(seg);
out_unlock:
mutex_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;
mutex_lock(&dcss_lock);
seg = segment_by_name (name);
if (seg == NULL) {
pr_err("Unloading unknown DCSS %s failed\n", name);
goto out_unlock;
}
if (atomic_dec_return(&seg->ref_count) != 0)
goto out_unlock;
release_resource(seg->res);
kfree(seg->res);
vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
list_del(&seg->list);
dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
kfree(seg);
out_unlock:
mutex_unlock(&dcss_lock);
}
/*
* save segment content permanently
*/
void
segment_save(char *name)
{
struct dcss_segment *seg;
char cmd1[160];
char cmd2[80];
int i, response;
if (!MACHINE_IS_VM)
return;
mutex_lock(&dcss_lock);
seg = segment_by_name (name);
if (seg == NULL) {
pr_err("Saving unknown DCSS %s failed\n", name);
goto out;
}
sprintf(cmd1, "DEFSEG %s", name);
for (i=0; i<seg->segcnt; i++) {
sprintf(cmd1+strlen(cmd1), " %lX-%lX %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);
response = 0;
cpcmd(cmd1, NULL, 0, &response);
if (response) {
pr_err("Saving a DCSS failed with DEFSEG response code "
"%i\n", response);
goto out;
}
cpcmd(cmd2, NULL, 0, &response);
if (response) {
pr_err("Saving a DCSS failed with SAVESEG response code "
"%i\n", response);
goto out;
}
out:
mutex_unlock(&dcss_lock);
}
/*
* print appropriate error message for segment_load()/segment_type()
* return code
*/
void segment_warning(int rc, char *seg_name)
{
switch (rc) {
case -ENOENT:
pr_err("DCSS %s cannot be loaded or queried\n", seg_name);
break;
case -ENOSYS:
pr_err("DCSS %s cannot be loaded or queried without "
"z/VM\n", seg_name);
break;
case -EIO:
pr_err("Loading or querying DCSS %s resulted in a "
"hardware error\n", seg_name);
break;
case -EOPNOTSUPP:
pr_err("DCSS %s has multiple page ranges and cannot be "
"loaded or queried\n", seg_name);
break;
case -ENOSPC:
pr_err("DCSS %s overlaps with used storage and cannot "
"be loaded\n", seg_name);
break;
case -EBUSY:
pr_err("%s needs used memory resources and cannot be "
"loaded or queried\n", seg_name);
break;
case -EPERM:
pr_err("DCSS %s is already loaded in a different access "
"mode\n", seg_name);
break;
case -ENOMEM:
pr_err("There is not enough memory to load or query "
"DCSS %s\n", seg_name);
break;
case -ERANGE:
pr_err("DCSS %s exceeds the kernel mapping range (%lu) "
"and cannot be loaded\n", seg_name, VMEM_MAX_PHYS);
break;
default:
break;
}
}
EXPORT_SYMBOL(segment_load);
EXPORT_SYMBOL(segment_unload);
EXPORT_SYMBOL(segment_save);
EXPORT_SYMBOL(segment_type);
EXPORT_SYMBOL(segment_modify_shared);
EXPORT_SYMBOL(segment_warning);