[PATCH v2 1/1] riscv: Get cache information through sysconf

[Palmer Dabbelt]

On Tue, 03 Nov 2020 22:38:25 PST (-0800), zong.li@sifive.com wrote:
> On Fri, Oct 30, 2020 at 1:33 AM Zong Li <zong.li@sifive.com> wrote:
>>
>> Add support to query cache information on RISC-V through sysconf()
>> function. The cache information had been added in AUX vector of RISC-V
>> architecture in Linux kernel v.5.10-rc1.
>> ---
>>  sysdeps/unix/sysv/linux/riscv/sysconf.c | 100 ++++++++++++++++++++++++
>>  1 file changed, 100 insertions(+)
>>  create mode 100644 sysdeps/unix/sysv/linux/riscv/sysconf.c
>>
>> diff --git a/sysdeps/unix/sysv/linux/riscv/sysconf.c b/sysdeps/unix/sysv/linux/riscv/sysconf.c
>> new file mode 100644
>> index 0000000000..02b469cc65
>> --- /dev/null
>> +++ b/sysdeps/unix/sysv/linux/riscv/sysconf.c
>> @@ -0,0 +1,100 @@
>> +/* Copyright (C) 2020 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
>> +   <https://www.gnu.org/licenses/>.  */
>> +
>> +#include <errno.h>
>> +#include <unistd.h>
>> +#include <sys/auxv.h>
>> +
>> +static long int linux_sysconf (int name);
>> +
>> +static inline bool
>> +getauxval2_einval (unsigned long int type, unsigned long int *result)
>> +{
>> +  if (__getauxval2 (type, result))
>> +    return true;
>> +
>> +  __set_errno (EINVAL);
>> +
>> +  return false;
>> +}
>> +
>> +static inline long int
>> +sysconf_get_cache_associativity (unsigned long type)
>> +{
>> +  unsigned long int result;
>> +
>> +  if (getauxval2_einval (type, &result))
>> +    return (result & 0xffff0000) >> 16;
>> +
>> +  return -1;
>> +}
>> +
>> +static inline long int
>> +sysconf_get_cache_linesize (unsigned long type)
>> +{
>> +  unsigned long int result;
>> +
>> +  if (getauxval2_einval (type, &result))
>> +    return result & 0xffff;
>> +
>> +  return -1;
>> +}
>> +
>> +static inline long int
>> +sysconf_get_cache_size (unsigned long type)
>> +{
>> +  unsigned long int result;
>> +
>> +  if (getauxval2_einval (type, &result))
>> +    return result;
>> +
>> +  return -1;
>> +}
>> +
>> +/* Get the value of the system variable NAME.  */
>> +long int
>> +__sysconf (int name)
>> +{
>> +  switch (name)
>> +    {
>> +      case _SC_LEVEL1_ICACHE_SIZE:
>> +       return sysconf_get_cache_size (AT_L1I_CACHESIZE);
>> +      case _SC_LEVEL1_ICACHE_ASSOC:
>> +       return sysconf_get_cache_associativity (AT_L1I_CACHEGEOMETRY);
>> +      case _SC_LEVEL1_ICACHE_LINESIZE:
>> +       return sysconf_get_cache_linesize (AT_L1I_CACHEGEOMETRY);
>> +      case _SC_LEVEL1_DCACHE_SIZE:
>> +       return sysconf_get_cache_size (AT_L1D_CACHESIZE);
>> +      case _SC_LEVEL1_DCACHE_ASSOC:
>> +       return sysconf_get_cache_associativity (AT_L1D_CACHEGEOMETRY);
>> +      case _SC_LEVEL1_DCACHE_LINESIZE:
>> +       return sysconf_get_cache_linesize (AT_L1D_CACHEGEOMETRY);
>> +      case _SC_LEVEL2_CACHE_SIZE:
>> +       return sysconf_get_cache_size (AT_L2_CACHESIZE);
>> +      case _SC_LEVEL2_CACHE_ASSOC:
>> +       return sysconf_get_cache_associativity (AT_L2_CACHEGEOMETRY);
>> +      case _SC_LEVEL2_CACHE_LINESIZE:
>> +       return sysconf_get_cache_linesize (AT_L2_CACHEGEOMETRY);
>> +      default:
>> +       return linux_sysconf (name);
>> +    }
>> +}
>> +
>> +/* Now the generic Linux version.  */
>> +#undef __sysconf
>> +#define __sysconf static linux_sysconf
>> +#include <sysdeps/unix/sysv/linux/sysconf.c>
>> --
>> 2.28.0
>>
>
> ping

Oh, sorry, repiled to the old one.

Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>