S/390: Get cache information via sysconf

This patch adds support to query cache information on s390
via sysconf() function - e.g. with _SC_LEVEL1_ICACHE_SIZE.
The attributes size, linesize and assoc can be queried
for cache level 1 - 4 via "extract cpu attribute" instruction,
which was first available with z10.

* NEWS: Mention sysconf() cache information support for s390.
* sysdeps/unix/sysv/linux/s390/sysconf.c: New File.
This commit is contained in:
Stefan Liebler 2015-04-24 13:34:17 +02:00 committed by Andreas Krebbel
parent 92f2897953
commit f7fba80508
3 changed files with 238 additions and 0 deletions

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@ -1,3 +1,8 @@
2015-04-24 Stefan Liebler <stli@linux.vnet.ibm.com>
* NEWS: Mention sysconf() cache information support for s390.
* sysdeps/unix/sysv/linux/s390/sysconf.c: New File.
2015-04-22 Wilco Dijkstra <wdijkstr@arm.com> 2015-04-22 Wilco Dijkstra <wdijkstr@arm.com>
* math/k_casinh.c (__kernel_casinh): Use __copysign. * math/k_casinh.c (__kernel_casinh): Use __copysign.

3
NEWS
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@ -18,6 +18,9 @@ Version 2.22
18080, 18093, 18100, 18104, 18110, 18111, 18128, 18138, 18185, 18197, 18080, 18093, 18100, 18104, 18110, 18111, 18128, 18138, 18185, 18197,
18206, 18210, 18211, 18247, 18287. 18206, 18210, 18211, 18247, 18287.
* Cache information can be queried via sysconf() function on s390 e.g. with
_SC_LEVEL1_ICACHE_SIZE as argument.
* A buffer overflow in gethostbyname_r and related functions performing DNS * A buffer overflow in gethostbyname_r and related functions performing DNS
requests has been fixed. If the NSS functions were called with a requests has been fixed. If the NSS functions were called with a
misaligned buffer, the buffer length change due to pointer alignment was misaligned buffer, the buffer length change due to pointer alignment was

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@ -0,0 +1,230 @@
/* Get system parameters, e.g. cache information. S390/S390x version.
Copyright (C) 2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library. If not, see
<http://www.gnu.org/licenses/>. */
#include <unistd.h>
#include <dl-procinfo.h>
static long int linux_sysconf (int name);
/* Possible arguments for get_cache_info.
The values are reflecting the level/attribute/type indications
of ecag-instruction (extract cpu attribue). */
#define CACHE_LEVEL_MAX 8
#define CACHE_ATTR_LINESIZE 1
#define CACHE_ATTR_SIZE 2
#define CACHE_ATTR_ASSOC 3
#define CACHE_TYPE_DATA 0
#define CACHE_TYPE_INSTRUCTION 1
static long
get_cache_info (int level, int attr, int type)
{
unsigned long int val;
unsigned int cmd;
unsigned long int arg;
/* Check arguments. */
if (level < 1 || level > CACHE_LEVEL_MAX
|| attr < CACHE_ATTR_LINESIZE || attr > CACHE_ATTR_ASSOC
|| type < CACHE_TYPE_DATA || type > CACHE_TYPE_INSTRUCTION)
return 0L;
/* Check if ecag-instruction is available.
ecag - extract CPU attribute (only in zarch; arch >= z10; in as 2.24) */
if (!(GLRO (dl_hwcap) & HWCAP_S390_STFLE)
#if !defined __s390x__
|| !(GLRO (dl_hwcap) & HWCAP_S390_ZARCH)
|| !(GLRO (dl_hwcap) & HWCAP_S390_HIGH_GPRS)
#endif /* !__s390x__ */
)
{
/* stfle (or zarch, high-gprs on s390-32) is not available.
We are on an old machine. Return 256byte for LINESIZE for L1 d/i-cache,
otherwise 0. */
if (level == 1 && attr == CACHE_ATTR_LINESIZE)
return 256L;
else
return 0L;
}
/* Store facility list and check for z10.
(see ifunc-resolver for details) */
register unsigned long reg0 asm("0") = 0;
#ifdef __s390x__
unsigned long stfle_bits;
# define STFLE_Z10_MASK (1UL << (63 - 34))
#else
unsigned long long stfle_bits;
# define STFLE_Z10_MASK (1ULL << (63 - 34))
#endif /* !__s390x__ */
asm volatile(".machine push" "\n\t"
".machinemode \"zarch_nohighgprs\"\n\t"
".machine \"z9-109\"" "\n\t"
"stfle %0" "\n\t"
".machine pop" "\n"
: "=QS" (stfle_bits), "+d" (reg0)
: : "cc");
if (!(stfle_bits & STFLE_Z10_MASK))
{
/* We are at least on a z9 machine.
Return 256byte for LINESIZE for L1 d/i-cache,
otherwise 0. */
if (level == 1 && attr == CACHE_ATTR_LINESIZE)
return 256L;
else
return 0L;
}
/* Check cache topology, if cache is available at this level. */
arg = (CACHE_LEVEL_MAX - level) * 8;
asm volatile (".machine push\n\t"
".machine \"z10\"\n\t"
".machinemode \"zarch_nohighgprs\"\n\t"
"ecag %0,%%r0,0\n\t" /* returns 64bit unsigned integer. */
"srlg %0,%0,0(%1)\n\t" /* right align 8bit cache info field. */
".machine pop"
: "=&d" (val)
: "a" (arg)
);
val &= 0xCUL; /* Extract cache scope information from cache topology summary.
(bits 4-5 of 8bit-field; 00 means cache does not exist). */
if (val == 0)
return 0L;
/* Get cache information for level, attribute and type. */
cmd = (attr << 4) | ((level - 1) << 1) | type;
asm volatile (".machine push\n\t"
".machine \"z10\"\n\t"
".machinemode \"zarch_nohighgprs\"\n\t"
"ecag %0,%%r0,0(%1)\n\t"
".machine pop"
: "=d" (val)
: "a" (cmd)
);
return val;
}
long int
__sysconf (int name)
{
if (name >= _SC_LEVEL1_ICACHE_SIZE && name <= _SC_LEVEL4_CACHE_LINESIZE)
{
int level;
int attr;
int type;
switch (name)
{
case _SC_LEVEL1_ICACHE_SIZE:
level = 1;
attr = CACHE_ATTR_SIZE;
type = CACHE_TYPE_INSTRUCTION;
break;
case _SC_LEVEL1_ICACHE_ASSOC:
level = 1;
attr = CACHE_ATTR_ASSOC;
type = CACHE_TYPE_INSTRUCTION;
break;
case _SC_LEVEL1_ICACHE_LINESIZE:
level = 1;
attr = CACHE_ATTR_LINESIZE;
type = CACHE_TYPE_INSTRUCTION;
break;
case _SC_LEVEL1_DCACHE_SIZE:
level = 1;
attr = CACHE_ATTR_SIZE;
type = CACHE_TYPE_DATA;
break;
case _SC_LEVEL1_DCACHE_ASSOC:
level = 1;
attr = CACHE_ATTR_ASSOC;
type = CACHE_TYPE_DATA;
break;
case _SC_LEVEL1_DCACHE_LINESIZE:
level = 1;
attr = CACHE_ATTR_LINESIZE;
type = CACHE_TYPE_DATA;
break;
case _SC_LEVEL2_CACHE_SIZE:
level = 2;
attr = CACHE_ATTR_SIZE;
type = CACHE_TYPE_DATA;
break;
case _SC_LEVEL2_CACHE_ASSOC:
level = 2;
attr = CACHE_ATTR_ASSOC;
type = CACHE_TYPE_DATA;
break;
case _SC_LEVEL2_CACHE_LINESIZE:
level = 2;
attr = CACHE_ATTR_LINESIZE;
type = CACHE_TYPE_DATA;
break;
case _SC_LEVEL3_CACHE_SIZE:
level = 3;
attr = CACHE_ATTR_SIZE;
type = CACHE_TYPE_DATA;
break;
case _SC_LEVEL3_CACHE_ASSOC:
level = 3;
attr = CACHE_ATTR_ASSOC;
type = CACHE_TYPE_DATA;
break;
case _SC_LEVEL3_CACHE_LINESIZE:
level = 3;
attr = CACHE_ATTR_LINESIZE;
type = CACHE_TYPE_DATA;
break;
case _SC_LEVEL4_CACHE_SIZE:
level = 4;
attr = CACHE_ATTR_SIZE;
type = CACHE_TYPE_DATA;
break;
case _SC_LEVEL4_CACHE_ASSOC:
level = 4;
attr = CACHE_ATTR_ASSOC;
type = CACHE_TYPE_DATA;
break;
case _SC_LEVEL4_CACHE_LINESIZE:
level = 4;
attr = CACHE_ATTR_LINESIZE;
type = CACHE_TYPE_DATA;
break;
default:
level = 0;
attr = 0;
type = 0;
break;
}
return get_cache_info (level, attr, type);
}
return linux_sysconf (name);
}
/* Now the generic Linux version. */
#undef __sysconf
#define __sysconf static linux_sysconf
#include <sysdeps/unix/sysv/linux/sysconf.c>