|
1 |
| -//! Run-time feature detection for RISC-V on Linux. |
2 |
| -
|
3 |
| -use super::auxvec; |
4 |
| -use crate::detect::{bit, cache, Feature}; |
5 |
| - |
6 |
| -/// Read list of supported features from the auxiliary vector. |
7 |
| -pub(crate) fn detect_features() -> cache::Initializer { |
8 |
| - let mut value = cache::Initializer::default(); |
9 |
| - let enable_feature = |value: &mut cache::Initializer, feature, enable| { |
10 |
| - if enable { |
11 |
| - value.set(feature as u32); |
12 |
| - } |
13 |
| - }; |
14 |
| - let enable_features = |value: &mut cache::Initializer, feature_slice: &[Feature], enable| { |
15 |
| - if enable { |
16 |
| - for feature in feature_slice { |
17 |
| - value.set(*feature as u32); |
18 |
| - } |
19 |
| - } |
20 |
| - }; |
21 |
| - |
22 |
| - // The values are part of the platform-specific [asm/hwcap.h][hwcap] |
23 |
| - // |
24 |
| - // [hwcap]: https://github.com/torvalds/linux/blob/master/arch/riscv/include/asm/hwcap.h |
25 |
| - let auxv = auxvec::auxv().expect("read auxvec"); // should not fail on RISC-V platform |
26 |
| - enable_feature( |
27 |
| - &mut value, |
28 |
| - Feature::a, |
29 |
| - bit::test(auxv.hwcap, (b'a' - b'a').into()), |
30 |
| - ); |
31 |
| - enable_feature( |
32 |
| - &mut value, |
33 |
| - Feature::c, |
34 |
| - bit::test(auxv.hwcap, (b'c' - b'a').into()), |
35 |
| - ); |
36 |
| - enable_features( |
37 |
| - &mut value, |
38 |
| - &[Feature::d, Feature::f, Feature::zicsr], |
39 |
| - bit::test(auxv.hwcap, (b'd' - b'a').into()), |
40 |
| - ); |
41 |
| - enable_features( |
42 |
| - &mut value, |
43 |
| - &[Feature::f, Feature::zicsr], |
44 |
| - bit::test(auxv.hwcap, (b'f' - b'a').into()), |
45 |
| - ); |
46 |
| - let has_i = bit::test(auxv.hwcap, (b'i' - b'a').into()); |
47 |
| - // If future RV128I is supported, implement with `enable_feature` here |
48 |
| - #[cfg(target_pointer_width = "64")] |
49 |
| - enable_feature(&mut value, Feature::rv64i, has_i); |
50 |
| - #[cfg(target_pointer_width = "32")] |
51 |
| - enable_feature(&mut value, Feature::rv32i, has_i); |
52 |
| - #[cfg(target_pointer_width = "32")] |
53 |
| - enable_feature( |
54 |
| - &mut value, |
55 |
| - Feature::rv32e, |
56 |
| - bit::test(auxv.hwcap, (b'e' - b'a').into()), |
57 |
| - ); |
58 |
| - enable_feature( |
59 |
| - &mut value, |
60 |
| - Feature::h, |
61 |
| - bit::test(auxv.hwcap, (b'h' - b'a').into()), |
62 |
| - ); |
63 |
| - enable_feature( |
64 |
| - &mut value, |
65 |
| - Feature::m, |
66 |
| - bit::test(auxv.hwcap, (b'm' - b'a').into()), |
67 |
| - ); |
68 |
| - // FIXME: Auxvec does not show supervisor feature support, but this mode may be useful |
69 |
| - // to detect when Rust is used to write Linux kernel modules. |
70 |
| - // These should be more than Auxvec way to detect supervisor features. |
71 |
| - |
72 |
| - value |
73 |
| -} |
| 1 | +//! Run-time feature detection for RISC-V on Linux. |
| 2 | +
|
| 3 | +use super::auxvec; |
| 4 | +use crate::detect::{bit, cache, Feature}; |
| 5 | + |
| 6 | +/// Read list of supported features from the auxiliary vector. |
| 7 | +pub(crate) fn detect_features() -> cache::Initializer { |
| 8 | + let mut value = cache::Initializer::default(); |
| 9 | + let enable_feature = |value: &mut cache::Initializer, feature, enable| { |
| 10 | + if enable { |
| 11 | + value.set(feature as u32); |
| 12 | + } |
| 13 | + }; |
| 14 | + let enable_features = |value: &mut cache::Initializer, feature_slice: &[Feature], enable| { |
| 15 | + if enable { |
| 16 | + for feature in feature_slice { |
| 17 | + value.set(*feature as u32); |
| 18 | + } |
| 19 | + } |
| 20 | + }; |
| 21 | + |
| 22 | + // The values are part of the platform-specific [asm/hwcap.h][hwcap] |
| 23 | + // |
| 24 | + // [hwcap]: https://github.com/torvalds/linux/blob/master/arch/riscv/include/asm/hwcap.h |
| 25 | + let auxv = auxvec::auxv().expect("read auxvec"); // should not fail on RISC-V platform |
| 26 | + enable_feature( |
| 27 | + &mut value, |
| 28 | + Feature::a, |
| 29 | + bit::test(auxv.hwcap, (b'a' - b'a').into()), |
| 30 | + ); |
| 31 | + enable_feature( |
| 32 | + &mut value, |
| 33 | + Feature::c, |
| 34 | + bit::test(auxv.hwcap, (b'c' - b'a').into()), |
| 35 | + ); |
| 36 | + enable_features( |
| 37 | + &mut value, |
| 38 | + &[Feature::d, Feature::f, Feature::zicsr], |
| 39 | + bit::test(auxv.hwcap, (b'd' - b'a').into()), |
| 40 | + ); |
| 41 | + enable_features( |
| 42 | + &mut value, |
| 43 | + &[Feature::f, Feature::zicsr], |
| 44 | + bit::test(auxv.hwcap, (b'f' - b'a').into()), |
| 45 | + ); |
| 46 | + let has_i = bit::test(auxv.hwcap, (b'i' - b'a').into()); |
| 47 | + // If future RV128I is supported, implement with `enable_feature` here |
| 48 | + #[cfg(target_pointer_width = "64")] |
| 49 | + enable_feature(&mut value, Feature::rv64i, has_i); |
| 50 | + #[cfg(target_pointer_width = "32")] |
| 51 | + enable_feature(&mut value, Feature::rv32i, has_i); |
| 52 | + #[cfg(target_pointer_width = "32")] |
| 53 | + enable_feature( |
| 54 | + &mut value, |
| 55 | + Feature::rv32e, |
| 56 | + bit::test(auxv.hwcap, (b'e' - b'a').into()), |
| 57 | + ); |
| 58 | + enable_feature( |
| 59 | + &mut value, |
| 60 | + Feature::h, |
| 61 | + bit::test(auxv.hwcap, (b'h' - b'a').into()), |
| 62 | + ); |
| 63 | + enable_feature( |
| 64 | + &mut value, |
| 65 | + Feature::m, |
| 66 | + bit::test(auxv.hwcap, (b'm' - b'a').into()), |
| 67 | + ); |
| 68 | + // FIXME: Auxvec does not show supervisor feature support, but this mode may be useful |
| 69 | + // to detect when Rust is used to write Linux kernel modules. |
| 70 | + // These should be more than Auxvec way to detect supervisor features. |
| 71 | + |
| 72 | + value |
| 73 | +} |
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