-
-
Notifications
You must be signed in to change notification settings - Fork 17
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
riscv64: Support 128-bit atomics (Zacas extension)
- Loading branch information
Showing
15 changed files
with
626 additions
and
15 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,107 @@ | ||
| // SPDX-License-Identifier: Apache-2.0 OR MIT | ||
|
|
||
| /* | ||
| Run-time CPU feature detection on RISC-V Linux/Android by using riscv_hwprobe. | ||
| On RISC-V, detection using auxv only supports single-letter extensions. | ||
| Refs: | ||
| - /~https://github.com/torvalds/linux/blob/v6.10/Documentation/arch/riscv/hwprobe.rst | ||
| - /~https://github.com/golang/sys/commit/3283fc3f6160baf63bec24fbaa24e094e9ff6daf | ||
| */ | ||
|
|
||
| include!("common.rs"); | ||
|
|
||
| // core::ffi::c_* (except c_void) requires Rust 1.64, libc will soon require Rust 1.47 | ||
| #[allow(non_camel_case_types, non_upper_case_globals)] | ||
| mod ffi { | ||
| pub(crate) use super::c_types::c_long; | ||
|
|
||
| // /~https://github.com/torvalds/linux/blob/v6.10/arch/riscv/include/uapi/asm/hwprobe.h | ||
| #[derive(Copy, Clone)] | ||
| #[repr(C)] | ||
| pub(crate) struct riscv_hwprobe { | ||
| pub(crate) key: i64, | ||
| pub(crate) value: u64, | ||
| } | ||
|
|
||
| pub(crate) const __NR_riscv_hwprobe: c_long = 258; | ||
|
|
||
| // /~https://github.com/torvalds/linux/blob/v6.10/arch/riscv/include/uapi/asm/hwprobe.h | ||
| pub(crate) const RISCV_HWPROBE_KEY_IMA_EXT_0: i64 = 4; | ||
| // Linux 6.8+ | ||
| // /~https://github.com/torvalds/linux/commit/154a3706122978eeb34d8223d49285ed4f3c61fa | ||
| pub(crate) const RISCV_HWPROBE_EXT_ZACAS: u64 = 1 << 34; | ||
|
|
||
| extern "C" { | ||
| // https://man7.org/linux/man-pages/man2/syscall.2.html | ||
| pub(crate) fn syscall(number: c_long, ...) -> c_long; | ||
| } | ||
| } | ||
|
|
||
| // syscall returns an unsupported error if riscv_hwprobe is not supported, | ||
| // so we can safely use this function on older versions of Linux. | ||
| fn riscv_hwprobe(out: &mut ffi::riscv_hwprobe, flags: usize) -> bool { | ||
| // SAFETY: We've passed the valid pointer and length. | ||
| unsafe { | ||
| ffi::syscall( | ||
| ffi::__NR_riscv_hwprobe, | ||
| out as *mut ffi::riscv_hwprobe, | ||
| 1_usize, | ||
| 0_usize, | ||
| 0_usize, | ||
| flags, | ||
| 0_usize, | ||
| ) == 0 | ||
| } | ||
| } | ||
|
|
||
| #[cold] | ||
| fn _detect(info: &mut CpuInfo) { | ||
| let mut out = ffi::riscv_hwprobe { key: ffi::RISCV_HWPROBE_KEY_IMA_EXT_0, value: 0 }; | ||
| if riscv_hwprobe(&mut out, 0) { | ||
| if out.key != -1 { | ||
| let value = out.value; | ||
| if value & ffi::RISCV_HWPROBE_EXT_ZACAS != 0 { | ||
| info.set(CpuInfo::HAS_ZACAS); | ||
| } | ||
| } | ||
| } | ||
| } | ||
|
|
||
| #[allow( | ||
| clippy::alloc_instead_of_core, | ||
| clippy::std_instead_of_alloc, | ||
| clippy::std_instead_of_core, | ||
| clippy::undocumented_unsafe_blocks, | ||
| clippy::wildcard_imports | ||
| )] | ||
| #[cfg(test)] | ||
| mod tests { | ||
| use super::*; | ||
|
|
||
| // Static assertions for FFI bindings. | ||
| // This checks that FFI bindings defined in this crate, FFI bindings defined | ||
| // in libc, and FFI bindings generated for the platform's latest header file | ||
| // using bindgen have compatible signatures (or the same values if constants). | ||
| // Since this is static assertion, we can detect problems with | ||
| // `cargo check --tests --target <target>` run in CI (via TESTS=1 build.sh) | ||
| // without actually running tests on these platforms. | ||
| // See also tools/codegen/src/ffi.rs. | ||
| // TODO(codegen): auto-generate this test | ||
| #[allow( | ||
| clippy::cast_possible_wrap, | ||
| clippy::cast_sign_loss, | ||
| clippy::no_effect_underscore_binding | ||
| )] | ||
| const _: fn() = || { | ||
| use test_helper::sys; | ||
| // TODO: syscall,riscv_hwprobe | ||
| // static_assert!(ffi::__NR_riscv_hwprobe == libc::__NR_riscv_hwprobe); // libc doesn't have this | ||
| static_assert!(ffi::__NR_riscv_hwprobe == sys::__NR_riscv_hwprobe as ffi::c_long); | ||
| // static_assert!(ffi::RISCV_HWPROBE_KEY_IMA_EXT_0 == libc::RISCV_HWPROBE_KEY_IMA_EXT_0); // libc doesn't have this | ||
| static_assert!(ffi::RISCV_HWPROBE_KEY_IMA_EXT_0 == sys::RISCV_HWPROBE_KEY_IMA_EXT_0 as i64); | ||
| // static_assert!(ffi::RISCV_HWPROBE_EXT_ZACAS == libc::RISCV_HWPROBE_EXT_ZACAS); // libc doesn't have this | ||
| static_assert!(ffi::RISCV_HWPROBE_EXT_ZACAS == sys::RISCV_HWPROBE_EXT_ZACAS); | ||
| }; | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.