@@ -1,6 +1,14 @@
ifeq ($(subdir),misc)
-sysdep_headers += sys/cachectl.h
-sysdep_routines += flush-icache
+sysdep_headers += \
+ sys/cachectl.h \
+ sys/hwprobe.h \
+ # sysdep_headers
+
+sysdep_routines += \
+ flush-icache \
+ hwprobe \
+ # sysdep_routines
+
endif
ifeq ($(subdir),stdlib)
@@ -8,4 +8,7 @@ libc {
GLIBC_2.27 {
__riscv_flush_icache;
}
+ GLIBC_2.40 {
+ __riscv_hwprobe;
+ }
}
new file mode 100644
@@ -0,0 +1,36 @@
+/* RISC-V hardware feature probing support on Linux
+ Copyright (C) 2024 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 <sys/hwprobe.h>
+#include <sysdep.h>
+#include <sysdep-vdso.h>
+
+int __riscv_hwprobe (struct riscv_hwprobe *pairs, size_t pair_count,
+ size_t cpu_count, unsigned long int *cpus,
+ unsigned int flags)
+{
+ int r;
+
+ r = INTERNAL_SYSCALL_CALL (riscv_hwprobe, pairs, pair_count,
+ cpu_count, cpus, flags);
+
+ /* Negate negative errno values to match pthreads API. */
+ return -r;
+}
@@ -2511,3 +2511,4 @@ GLIBC_2.39 stdc_trailing_zeros_ui F
GLIBC_2.39 stdc_trailing_zeros_ul F
GLIBC_2.39 stdc_trailing_zeros_ull F
GLIBC_2.39 stdc_trailing_zeros_us F
+GLIBC_2.40 __riscv_hwprobe F
@@ -2711,3 +2711,4 @@ GLIBC_2.39 stdc_trailing_zeros_ui F
GLIBC_2.39 stdc_trailing_zeros_ul F
GLIBC_2.39 stdc_trailing_zeros_ull F
GLIBC_2.39 stdc_trailing_zeros_us F
+GLIBC_2.40 __riscv_hwprobe F
new file mode 100644
@@ -0,0 +1,74 @@
+/* RISC-V architecture probe interface
+ Copyright (C) 2024 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 <stddef.h>
+#ifdef __has_include
+# if __has_include (<asm/hwprobe.h>)
+# include <asm/hwprobe.h>
+# endif
+#endif
+
+/* Define a (probably stale) version of the interface if the Linux headers
+ aren't present. */
+#ifndef RISCV_HWPROBE_KEY_MVENDORID
+struct riscv_hwprobe {
+ signed long long int key;
+ unsigned long long int value;
+};
+
+#define RISCV_HWPROBE_KEY_MVENDORID 0
+#define RISCV_HWPROBE_KEY_MARCHID 1
+#define RISCV_HWPROBE_KEY_MIMPID 2
+#define RISCV_HWPROBE_KEY_BASE_BEHAVIOR 3
+#define RISCV_HWPROBE_BASE_BEHAVIOR_IMA (1 << 0)
+#define RISCV_HWPROBE_KEY_IMA_EXT_0 4
+#define RISCV_HWPROBE_IMA_FD (1 << 0)
+#define RISCV_HWPROBE_IMA_C (1 << 1)
+#define RISCV_HWPROBE_IMA_V (1 << 2)
+#define RISCV_HWPROBE_EXT_ZBA (1 << 3)
+#define RISCV_HWPROBE_EXT_ZBB (1 << 4)
+#define RISCV_HWPROBE_EXT_ZBS (1 << 5)
+#define RISCV_HWPROBE_EXT_ZICBOZ (1 << 6)
+#define RISCV_HWPROBE_KEY_CPUPERF_0 5
+#define RISCV_HWPROBE_MISALIGNED_UNKNOWN (0 << 0)
+#define RISCV_HWPROBE_MISALIGNED_EMULATED (1 << 0)
+#define RISCV_HWPROBE_MISALIGNED_SLOW (2 << 0)
+#define RISCV_HWPROBE_MISALIGNED_FAST (3 << 0)
+#define RISCV_HWPROBE_MISALIGNED_UNSUPPORTED (4 << 0)
+#define RISCV_HWPROBE_MISALIGNED_MASK (7 << 0)
+#define RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE 6
+
+#endif /* RISCV_HWPROBE_KEY_MVENDORID */
+
+__BEGIN_DECLS
+
+extern int __riscv_hwprobe (struct riscv_hwprobe *__pairs, size_t __pair_count,
+ size_t __cpu_count, unsigned long int *__cpus,
+ unsigned int __flags)
+ __nonnull ((1)) __wur
+ __fortified_attr_access (__read_write__, 1, 2)
+ __fortified_attr_access (__read_only__, 4, 3);
+
+__END_DECLS
+
+#endif /* sys/hwprobe.h */
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> --- (no changes since v12) Changes in v12: - Updated version to 2.40 Changes in v11: - Update copyright year (Adhemerval) Changes in v10: - Remove spurious 5 from syscall patch (Adhemerval) - Use one item per line in Makefile (Adhemerval) - Remove double underscores from __riscv_hwprobe definition (Adhemerval) - Use only spaces in macro definitions of hwprobe.h (Adhemerval) Changes in v9: - Alphabetize new entries in libc.abilist (to pass checks) Changes in v8: - Fix missed 2.39 in abilists (Joseph) - Just return -r (Florian) Changes in v7: - Bumped Versions up to 2.39 (Joseph) - Used INTERNAL_SYSCALL_CALL, and return positive errno to match pthreads API (Florian). - Remove __THROW since it creates a warning in combination with the fortified access decorators. Changes in v6: - Prefixed __riscv_hwprobe() parameters names with __ to avoid user macro namespace pollution (Joseph) Changes in v4: - Remove __USE_GNU (Florian) - __nonnull, __wur, __THROW, and __fortified_attr_access decorations (Florian) - change long to long int (Florian) - Fix comment formatting (Florian) - Update backup kernel header content copy. - Fix function declaration formatting (Florian) - Changed export versions to 2.38 Changes in v3: - Update argument types to match v4 kernel interface Changes in v2: - hwprobe.h: Use __has_include and duplicate Linux content to make compilation work when Linux headers are absent (Adhemerval) - hwprobe.h: Put declaration under __USE_GNU (Adhemerval) - Use INLINE_SYSCALL_CALL (Adhemerval) - Update versions - Update UNALIGNED_MASK to match kernel v3 series. sysdeps/unix/sysv/linux/riscv/Makefile | 12 ++- sysdeps/unix/sysv/linux/riscv/Versions | 3 + sysdeps/unix/sysv/linux/riscv/hwprobe.c | 36 +++++++++ .../unix/sysv/linux/riscv/rv32/libc.abilist | 1 + .../unix/sysv/linux/riscv/rv64/libc.abilist | 1 + sysdeps/unix/sysv/linux/riscv/sys/hwprobe.h | 74 +++++++++++++++++++ 6 files changed, 125 insertions(+), 2 deletions(-) create mode 100644 sysdeps/unix/sysv/linux/riscv/hwprobe.c create mode 100644 sysdeps/unix/sysv/linux/riscv/sys/hwprobe.h