arch: add mips64 support

.github/workflows/rust.yml

@@ -42,6 +42,11 @@ jobs:
           # sparc64 uses experimental asm features
           - target: sparc64-unknown-linux-gnu
             toolchain: nightly
+          # mips64 is tier-3 and uses experimental asm features
+          - target: mips64-unknown-linux-gnuabi64
+            toolchain: nightly
+            components: rust-src
+            build_std: true
 
     steps:
     - name: "Checkout"

crates/asm/src/lib.rs

@@ -6,11 +6,16 @@
 //! faster?
 //!
 //! Supports `x86_64`, `aarch64`, `riscv64`, `loongarch64`, `s390x`,
-//! `powerpc64`, `arm` (armv7), `riscv32`, and `sparc64` architectures.
+//! `powerpc64`, `arm` (armv7), `riscv32`, `sparc64`, and `mips64`
+//! architectures.
 
 #![no_std]
 #![cfg_attr(
-  any(target_arch = "powerpc64", target_arch = "sparc64"),
+  any(
+    target_arch = "powerpc64",
+    target_arch = "sparc64",
+    target_arch = "mips64"
+  ),
   feature(asm_experimental_arch)
 )]
 
@@ -24,11 +29,12 @@
   target_arch = "powerpc64",
   target_arch = "arm",
   target_arch = "riscv32",
-  target_arch = "sparc64"
+  target_arch = "sparc64",
+  target_arch = "mips64"
 )))]
 compile_error!(
   "Unsupported architecture: only x86_64, aarch64, riscv64, loongarch64, \
-   s390x, powerpc64, arm, riscv32, and sparc64 are supported"
+   s390x, powerpc64, arm, riscv32, sparc64, and mips64 are supported"
 );
 
 // Per-arch syscall implementations live in their own module files.
@@ -59,6 +65,9 @@ mod arch;
 #[cfg(target_arch = "sparc64")]
 #[path = "sparc64.rs"]
 mod arch;
+#[cfg(target_arch = "mips64")]
+#[path = "mips64.rs"]
+mod arch;
 
 /// Copies `n` bytes from `src` to `dest`.
 ///
@@ -295,7 +304,8 @@ pub unsafe fn sys_uname(buf: *mut UtsNameBuf) -> i32 {
 #[cfg(not(any(
   target_arch = "s390x",
   target_arch = "arm",
-  target_arch = "riscv32"
+  target_arch = "riscv32",
+  target_arch = "mips64"
 )))]
 pub struct StatfsBuf {
   pub f_type:    i64,
@@ -355,6 +365,27 @@ pub struct StatfsBuf {
   pub _pad: [u32; 4],
 }
 
+/// mips reorders fields; see
+/// https://github.com/torvalds/linux/blob/v6.19/arch/mips/include/uapi/asm/statfs.h
+#[repr(C)]
+#[cfg(target_arch = "mips64")]
+pub struct StatfsBuf {
+  pub f_type:    i64,
+  pub f_bsize:   i64,
+  pub f_frsize:  i64,
+  pub f_blocks:  u64,
+  pub f_bfree:   u64,
+  pub f_files:   u64,
+  pub f_ffree:   u64,
+  pub f_bavail:  u64,
+  pub f_fsid:    [i32; 2],
+  pub f_namelen: i64,
+  pub f_flags:   i64,
+
+  #[allow(clippy::pub_underscore_fields, reason = "This is not a public API")]
+  pub _pad: [i64; 5],
+}
+
 /// Direct `statfs(2)` syscall
 ///
 /// # Returns

crates/asm/src/mips64.rs

@@ -0,0 +1,206 @@
+//! Syscall implementations for `mips64`.
+
+use super::{StatfsBuf, SysInfo, UtsNameBuf};
+
+pub(super) unsafe fn sys_open(path: *const u8, flags: i32) -> i32 {
+  unsafe {
+    let ret: i64;
+    core::arch::asm!(
+      "syscall",
+      "beqz $7, 1f",
+      "nop",
+      "dsubu $2, $0, $2",
+      "1:",
+      inlateout("$2") 5000i64 + 2 => ret,  // SYS_open
+      in("$4") path,
+      in("$5") flags,
+      in("$6") 0i32,  // mode
+      lateout("$7") _,
+      lateout("$8") _, lateout("$9") _, lateout("$10") _, lateout("$11") _,
+      lateout("$12") _, lateout("$13") _, lateout("$14") _, lateout("$15") _,
+      lateout("$24") _, lateout("$25") _,
+      options(nostack)
+    );
+    #[allow(clippy::cast_possible_truncation)]
+    {
+      ret as i32
+    }
+  }
+}
+
+pub(super) unsafe fn sys_read(fd: i32, buf: *mut u8, count: usize) -> isize {
+  unsafe {
+    let ret: i64;
+    core::arch::asm!(
+      "syscall",
+      "beqz $7, 1f",
+      "nop",
+      "dsubu $2, $0, $2",
+      "1:",
+      inlateout("$2") 5000i64 + 0 => ret,  // SYS_read
+      in("$4") fd,
+      in("$5") buf,
+      in("$6") count,
+      lateout("$7") _,
+      lateout("$8") _, lateout("$9") _, lateout("$10") _, lateout("$11") _,
+      lateout("$12") _, lateout("$13") _, lateout("$14") _, lateout("$15") _,
+      lateout("$24") _, lateout("$25") _,
+      options(nostack)
+    );
+    ret as isize
+  }
+}
+
+pub(super) unsafe fn sys_write(fd: i32, buf: *const u8, count: usize) -> isize {
+  unsafe {
+    let ret: i64;
+    core::arch::asm!(
+      "syscall",
+      "beqz $7, 1f",
+      "nop",
+      "dsubu $2, $0, $2",
+      "1:",
+      inlateout("$2") 5000i64 + 1 => ret,  // SYS_write
+      in("$4") fd,
+      in("$5") buf,
+      in("$6") count,
+      lateout("$7") _,
+      lateout("$8") _, lateout("$9") _, lateout("$10") _, lateout("$11") _,
+      lateout("$12") _, lateout("$13") _, lateout("$14") _, lateout("$15") _,
+      lateout("$24") _, lateout("$25") _,
+      options(nostack)
+    );
+    ret as isize
+  }
+}
+
+pub(super) unsafe fn sys_close(fd: i32) -> i32 {
+  unsafe {
+    let ret: i64;
+    core::arch::asm!(
+      "syscall",
+      "beqz $7, 1f",
+      "nop",
+      "dsubu $2, $0, $2",
+      "1:",
+      inlateout("$2") 5000i64 + 3 => ret,  // SYS_close
+      in("$4") fd,
+      lateout("$7") _,
+      lateout("$8") _, lateout("$9") _, lateout("$10") _, lateout("$11") _,
+      lateout("$12") _, lateout("$13") _, lateout("$14") _, lateout("$15") _,
+      lateout("$24") _, lateout("$25") _,
+      options(nostack)
+    );
+    #[allow(clippy::cast_possible_truncation)]
+    {
+      ret as i32
+    }
+  }
+}
+
+pub(super) unsafe fn sys_uname(buf: *mut UtsNameBuf) -> i32 {
+  unsafe {
+    let ret: i64;
+    core::arch::asm!(
+      "syscall",
+      "beqz $7, 1f",
+      "nop",
+      "dsubu $2, $0, $2",
+      "1:",
+      inlateout("$2") 5000i64 + 61 => ret,  // SYS_newuname
+      in("$4") buf,
+      lateout("$7") _,
+      lateout("$8") _, lateout("$9") _, lateout("$10") _, lateout("$11") _,
+      lateout("$12") _, lateout("$13") _, lateout("$14") _, lateout("$15") _,
+      lateout("$24") _, lateout("$25") _,
+      options(nostack)
+    );
+    #[allow(clippy::cast_possible_truncation)]
+    {
+      ret as i32
+    }
+  }
+}
+
+pub(super) unsafe fn sys_statfs(path: *const u8, buf: *mut StatfsBuf) -> i32 {
+  unsafe {
+    let ret: i64;
+    core::arch::asm!(
+      "syscall",
+      "beqz $7, 1f",
+      "nop",
+      "dsubu $2, $0, $2",
+      "1:",
+      inlateout("$2") 5000i64 + 134 => ret,  // SYS_statfs
+      in("$4") path,
+      in("$5") buf,
+      lateout("$7") _,
+      lateout("$8") _, lateout("$9") _, lateout("$10") _, lateout("$11") _,
+      lateout("$12") _, lateout("$13") _, lateout("$14") _, lateout("$15") _,
+      lateout("$24") _, lateout("$25") _,
+      options(nostack)
+    );
+    #[allow(clippy::cast_possible_truncation)]
+    {
+      ret as i32
+    }
+  }
+}
+
+pub(super) unsafe fn sys_sysinfo(info: *mut SysInfo) -> i64 {
+  unsafe {
+    let ret: i64;
+    core::arch::asm!(
+      "syscall",
+      "beqz $7, 1f",
+      "nop",
+      "dsubu $2, $0, $2",
+      "1:",
+      inlateout("$2") 5000_i64 + 97 => ret,  // SYS_sysinfo
+      in("$4") info,
+      lateout("$7") _,
+      lateout("$8") _, lateout("$9") _, lateout("$10") _, lateout("$11") _,
+      lateout("$12") _, lateout("$13") _, lateout("$14") _, lateout("$15") _,
+      lateout("$24") _, lateout("$25") _,
+      options(nostack)
+    );
+    ret
+  }
+}
+
+pub(super) unsafe fn sys_sched_getaffinity(
+  pid: i32,
+  mask_size: usize,
+  mask: *mut u8,
+) -> i32 {
+  unsafe {
+    let ret: i64;
+    core::arch::asm!(
+      "syscall",
+      inlateout("$2") 5000i64 + 196 => ret,  // __NR_sched_getaffinity
+      in("$4") pid,
+      in("$5") mask_size,
+      in("$6") mask,
+      lateout("$7") _,
+      lateout("$8") _, lateout("$9") _, lateout("$10") _, lateout("$11") _,
+      lateout("$12") _, lateout("$13") _, lateout("$14") _, lateout("$15") _,
+      lateout("$24") _, lateout("$25") _,
+      options(nostack)
+    );
+    #[allow(clippy::cast_possible_truncation)]
+    {
+      ret as i32
+    }
+  }
+}
+
+pub(super) unsafe fn sys_exit(code: i32) -> ! {
+  unsafe {
+    core::arch::asm!(
+      "syscall",
+      in("$2") 5000i64 + 58,  // SYS_exit
+      in("$4") code,
+      options(noreturn, nostack)
+    );
+  }
+}

crates/lib/src/cpu.rs

@@ -190,6 +190,8 @@ fn get_cpu_freq_mhz() -> Option<u32> {
     b"cpu MHz static",
     b"CPU MHz",
     b"clock",
+    // BogoMIPS on MIPS is calibrated to the clock frequency (unlike x86).
+    b"BogoMIPS",
   ] {
     if let Some(val) = extract_field(data, key) {
       // Parse integer part of the MHz value (e.g. "5200.00" -> 5200)
@@ -270,6 +272,7 @@ fn extract_name(data: &[u8]) -> Option<String> {
     b"model name" as &[u8],
     b"Model Name",
     b"uarch",
+    b"cpu model",
     b"isa",
     b"cpu",
     b"machine",

microfetch/src/main.rs

@@ -1,7 +1,11 @@
 #![no_std]
 #![no_main]
 #![cfg_attr(
-  any(target_arch = "powerpc64", target_arch = "sparc64"),
+  any(
+    target_arch = "powerpc64",
+    target_arch = "sparc64",
+    target_arch = "mips64"
+  ),
   feature(asm_experimental_arch)
 )]
 
@@ -193,6 +197,22 @@ unsafe extern "C" fn _start() {
   );
 }
 
+#[cfg(target_arch = "mips64")]
+#[unsafe(no_mangle)]
+#[unsafe(naked)]
+unsafe extern "C" fn _start() {
+  naked_asm!(
+    "move $a0, $sp",       // first arg = original sp (argc/argv)
+    "daddiu $sp, $sp, -16",// reserve + keep 16-byte alignment (N64 ABI)
+    "jal {entry_rust}",
+    "nop",                 // delay slot
+    "move $a0, $v0",       // exit code = entry_rust return value
+    "li $v0, 5058",        // SYS_exit (5000 + 58)
+    "syscall",
+    entry_rust = sym entry_rust,
+  );
+}
+
 // Global allocator
 #[global_allocator]
 static ALLOCATOR: BumpAllocator = BumpAllocator::new();