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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
commit | 698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch) | |
tree | 173a775858bd501c378080a10dca74132f05bc50 /library/stdarch/crates/std_detect/src/detect/os/linux/riscv.rs | |
parent | Initial commit. (diff) | |
download | rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip |
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | library/stdarch/crates/std_detect/src/detect/os/linux/riscv.rs | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/library/stdarch/crates/std_detect/src/detect/os/linux/riscv.rs b/library/stdarch/crates/std_detect/src/detect/os/linux/riscv.rs new file mode 100644 index 000000000..1ec06959a --- /dev/null +++ b/library/stdarch/crates/std_detect/src/detect/os/linux/riscv.rs @@ -0,0 +1,73 @@ +//! Run-time feature detection for RISC-V on Linux.
+
+use super::auxvec;
+use crate::detect::{bit, cache, Feature};
+
+/// Read list of supported features from the auxiliary vector.
+pub(crate) fn detect_features() -> cache::Initializer {
+ let mut value = cache::Initializer::default();
+ let enable_feature = |value: &mut cache::Initializer, feature, enable| {
+ if enable {
+ value.set(feature as u32);
+ }
+ };
+ let enable_features = |value: &mut cache::Initializer, feature_slice: &[Feature], enable| {
+ if enable {
+ for feature in feature_slice {
+ value.set(*feature as u32);
+ }
+ }
+ };
+
+ // The values are part of the platform-specific [asm/hwcap.h][hwcap]
+ //
+ // [hwcap]: https://github.com/torvalds/linux/blob/master/arch/riscv/include/asm/hwcap.h
+ let auxv = auxvec::auxv().expect("read auxvec"); // should not fail on RISC-V platform
+ enable_feature(
+ &mut value,
+ Feature::a,
+ bit::test(auxv.hwcap, (b'a' - b'a').into()),
+ );
+ enable_feature(
+ &mut value,
+ Feature::c,
+ bit::test(auxv.hwcap, (b'c' - b'a').into()),
+ );
+ enable_features(
+ &mut value,
+ &[Feature::d, Feature::f, Feature::zicsr],
+ bit::test(auxv.hwcap, (b'd' - b'a').into()),
+ );
+ enable_features(
+ &mut value,
+ &[Feature::f, Feature::zicsr],
+ bit::test(auxv.hwcap, (b'f' - b'a').into()),
+ );
+ let has_i = bit::test(auxv.hwcap, (b'i' - b'a').into());
+ // If future RV128I is supported, implement with `enable_feature` here
+ #[cfg(target_pointer_width = "64")]
+ enable_feature(&mut value, Feature::rv64i, has_i);
+ #[cfg(target_pointer_width = "32")]
+ enable_feature(&mut value, Feature::rv32i, has_i);
+ #[cfg(target_pointer_width = "32")]
+ enable_feature(
+ &mut value,
+ Feature::rv32e,
+ bit::test(auxv.hwcap, (b'e' - b'a').into()),
+ );
+ enable_feature(
+ &mut value,
+ Feature::h,
+ bit::test(auxv.hwcap, (b'h' - b'a').into()),
+ );
+ enable_feature(
+ &mut value,
+ Feature::m,
+ bit::test(auxv.hwcap, (b'm' - b'a').into()),
+ );
+ // FIXME: Auxvec does not show supervisor feature support, but this mode may be useful
+ // to detect when Rust is used to write Linux kernel modules.
+ // These should be more than Auxvec way to detect supervisor features.
+
+ value
+}
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