[PATCH 1/1] riscv: Get cache information through sysconf
Palmer Dabbelt
palmer@dabbelt.com
Fri Nov 6 04:57:11 GMT 2020
On Mon, 26 Oct 2020 00:24:47 PDT (-0700), 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 | 74 +++++++++++++++++++++++++
> 1 file changed, 74 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..e73095528c
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/riscv/sysconf.c
> @@ -0,0 +1,74 @@
> +/* 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 long int
> +sysconf_get_cache_associativity (unsigned long type)
> +{
> + return (__getauxval (type) & 0xffff0000) >> 16;
> +}
> +
> +static inline long int
> +sysconf_get_cache_linesize (unsigned long type)
> +{
> + return __getauxval (type) & 0xffff;
> +}
> +
> +static inline long int
> +sysconf_get_cache_size (unsigned long type)
> +{
> + return __getauxval (type);
> +}
> +
> +/* 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>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
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