From: Evan Green <evan@rivosinc.com>
To: libc-alpha@sourceware.org
Cc: slewis@rivosinc.com, vineetg@rivosinc.com, palmer@rivosinc.com,
Evan Green <evan@rivosinc.com>
Subject: [PATCH 1/2] riscv: Add Linux hwprobe syscall support
Date: Mon, 6 Feb 2023 11:48:18 -0800 [thread overview]
Message-ID: <20230206194819.1679472-2-evan@rivosinc.com> (raw)
In-Reply-To: <20230206194819.1679472-1-evan@rivosinc.com>
Add awareness and a thin wrapper function around a new Linux system call
that allows callers to get architecture and microarchitecture
information about the CPUs from the kernel. This can be used to
do things like dynamically choose a memcpy implementation.
Signed-off-by: Evan Green <evan@rivosinc.com>
---
sysdeps/unix/sysv/linux/riscv/Makefile | 4 +--
sysdeps/unix/sysv/linux/riscv/Versions | 3 ++
sysdeps/unix/sysv/linux/riscv/hwprobe.c | 30 ++++++++++++++++
.../unix/sysv/linux/riscv/rv32/arch-syscall.h | 1 +
.../unix/sysv/linux/riscv/rv32/libc.abilist | 1 +
.../unix/sysv/linux/riscv/rv64/arch-syscall.h | 1 +
.../unix/sysv/linux/riscv/rv64/libc.abilist | 1 +
sysdeps/unix/sysv/linux/riscv/sys/hwprobe.h | 34 +++++++++++++++++++
sysdeps/unix/sysv/linux/syscall-names.list | 1 +
9 files changed, 74 insertions(+), 2 deletions(-)
create mode 100644 sysdeps/unix/sysv/linux/riscv/hwprobe.c
create mode 100644 sysdeps/unix/sysv/linux/riscv/sys/hwprobe.h
diff --git a/sysdeps/unix/sysv/linux/riscv/Makefile b/sysdeps/unix/sysv/linux/riscv/Makefile
index 4b6eacb32f..45cc29e40d 100644
--- a/sysdeps/unix/sysv/linux/riscv/Makefile
+++ b/sysdeps/unix/sysv/linux/riscv/Makefile
@@ -1,6 +1,6 @@
ifeq ($(subdir),misc)
-sysdep_headers += sys/cachectl.h
-sysdep_routines += flush-icache
+sysdep_headers += sys/cachectl.h sys/hwprobe.h
+sysdep_routines += flush-icache hwprobe
endif
ifeq ($(subdir),stdlib)
diff --git a/sysdeps/unix/sysv/linux/riscv/Versions b/sysdeps/unix/sysv/linux/riscv/Versions
index 5625d2a0b8..891ae05730 100644
--- a/sysdeps/unix/sysv/linux/riscv/Versions
+++ b/sysdeps/unix/sysv/linux/riscv/Versions
@@ -8,4 +8,7 @@ libc {
GLIBC_2.27 {
__riscv_flush_icache;
}
+ GLIBC_2.37 {
+ __riscv_hwprobe;
+ }
}
diff --git a/sysdeps/unix/sysv/linux/riscv/hwprobe.c b/sysdeps/unix/sysv/linux/riscv/hwprobe.c
new file mode 100644
index 0000000000..ef6dccb9db
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/riscv/hwprobe.c
@@ -0,0 +1,30 @@
+/* RISC-V hardware feature probing support on Linux
+ Copyright (C) 2023 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 <sys/syscall.h>
+#include <asm/hwprobe.h>
+#include <sysdep.h>
+
+int
+__riscv_hwprobe (struct riscv_hwprobe *pairs, long pair_count,
+ long cpu_count, unsigned long *cpus, unsigned long flags)
+{
+ return INLINE_SYSCALL (riscv_hwprobe, 5, pairs, pair_count,
+ cpu_count, cpus, flags);
+}
diff --git a/sysdeps/unix/sysv/linux/riscv/rv32/arch-syscall.h b/sysdeps/unix/sysv/linux/riscv/rv32/arch-syscall.h
index 202520ee25..2416e041c8 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv32/arch-syscall.h
+++ b/sysdeps/unix/sysv/linux/riscv/rv32/arch-syscall.h
@@ -198,6 +198,7 @@
#define __NR_request_key 218
#define __NR_restart_syscall 128
#define __NR_riscv_flush_icache 259
+#define __NR_riscv_hwprobe 258
#define __NR_rseq 293
#define __NR_rt_sigaction 134
#define __NR_rt_sigpending 136
diff --git a/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
index ff90d1bff2..f4c391d3be 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
@@ -2396,3 +2396,4 @@ GLIBC_2.36 pidfd_open F
GLIBC_2.36 pidfd_send_signal F
GLIBC_2.36 process_madvise F
GLIBC_2.36 process_mrelease F
+GLIBC_2.37 __riscv_hwprobe F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/arch-syscall.h b/sysdeps/unix/sysv/linux/riscv/rv64/arch-syscall.h
index 4e65f337d4..a32bc82f60 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv64/arch-syscall.h
+++ b/sysdeps/unix/sysv/linux/riscv/rv64/arch-syscall.h
@@ -205,6 +205,7 @@
#define __NR_request_key 218
#define __NR_restart_syscall 128
#define __NR_riscv_flush_icache 259
+#define __NR_riscv_hwprobe 258
#define __NR_rseq 293
#define __NR_rt_sigaction 134
#define __NR_rt_sigpending 136
diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
index f1017f6ec5..0f57bbe9e1 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
@@ -2596,3 +2596,4 @@ GLIBC_2.36 pidfd_open F
GLIBC_2.36 pidfd_send_signal F
GLIBC_2.36 process_madvise F
GLIBC_2.36 process_mrelease F
+GLIBC_2.37 __riscv_hwprobe F
diff --git a/sysdeps/unix/sysv/linux/riscv/sys/hwprobe.h b/sysdeps/unix/sysv/linux/riscv/sys/hwprobe.h
new file mode 100644
index 0000000000..da8cdc90bf
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/riscv/sys/hwprobe.h
@@ -0,0 +1,34 @@
+/* RISC-V architecture probe interface
+ Copyright (C) 2023 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/>. */
+
+#ifndef _SYS_HWPROBE_H
+#define _SYS_HWPROBE_H 1
+
+#include <features.h>
+#include <asm/hwprobe.h>
+
+__BEGIN_DECLS
+
+int
+__riscv_hwprobe (struct riscv_hwprobe *pairs, long pair_count,
+ long cpu_count, unsigned long *cpus, unsigned long flags);
+
+__END_DECLS
+
+#endif /* sys/hwprobe.h */
diff --git a/sysdeps/unix/sysv/linux/syscall-names.list b/sysdeps/unix/sysv/linux/syscall-names.list
index 822498d3e3..4f4a62e91c 100644
--- a/sysdeps/unix/sysv/linux/syscall-names.list
+++ b/sysdeps/unix/sysv/linux/syscall-names.list
@@ -477,6 +477,7 @@ renameat2
request_key
restart_syscall
riscv_flush_icache
+riscv_hwprobe
rmdir
rseq
rt_sigaction
--
2.25.1
next prev parent reply other threads:[~2023-02-06 19:48 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-06 19:48 [PATCH 0/2] RISC-V: ifunced memcpy using new kernel hwprobe interface Evan Green
2023-02-06 19:48 ` Evan Green [this message]
2023-02-07 13:05 ` [PATCH 1/2] riscv: Add Linux hwprobe syscall support Adhemerval Zanella Netto
2023-02-09 20:55 ` Evan Green
2023-02-12 16:58 ` Jeff Law
2023-02-06 19:48 ` [PATCH 2/2] riscv: Add and use alignment-ignorant memcpy Evan Green
2023-02-06 22:05 ` Richard Henderson
2023-02-09 21:04 ` Evan Green
2023-02-06 21:28 ` [PATCH 0/2] RISC-V: ifunced memcpy using new kernel hwprobe interface Richard Henderson
2023-02-07 12:49 ` Adhemerval Zanella Netto
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