Support BPF (experimental)

.cspell.json

@@ -51,6 +51,7 @@
   "ignorePaths": [
     "target-specs/**",
     "tools/valgrind/**",
-    "tests/asm-test/asm/**"
+    "tests/asm-test/asm/**",
+    "tests/bpf/LICENSE-*"
   ]
 }

.github/.cspell/project-dictionary.txt

@@ -15,6 +15,7 @@ balign
 beqz
 beqzc
 Bicc
+bindeps
 bnez
 boundedly
 brne
@@ -45,6 +46,7 @@ DWCAS
 eors
 espup
 fild
+filosottile
 fistp
 fstat
 gaisler
@@ -53,9 +55,11 @@ gettime
 GRLIB
 Halfword
 hwsync
+iface
 IMAFD
 inequal
 insertnopload
+insn
 ishld
 isync
 kuser
@@ -89,8 +93,10 @@ lwarx
 lwsync
 mcpu
 membar
+memcg
 memcheck
 memd
+memlock
 memw
 mfcr
 mfence
@@ -118,6 +124,8 @@ qbsp
 quadword
 rcpc
 risbg
+rlim
+rlimit
 rsbegin
 rsend
 RVWMO
@@ -128,6 +136,7 @@ SCWP
 SCWPE
 seqz
 sete
+setrlimit
 signedness
 simavr
 simio
@@ -169,6 +178,7 @@ versatilepb
 virt
 vmovdqa
 wokwi
+wreg
 xadd
 xchg
 xgetbv

.github/dependabot.yml

@@ -6,6 +6,7 @@ updates:
       # crates with [workspace] table are not recognized by the above 'directory: /'
       - /tests/asm-test
       - /tests/avr
+      - /tests/bpf
       - /tests/msp430
       - /tests/no-std-linux
       - /tests/no-std-qemu

.github/workflows/ci.yml

@@ -698,6 +698,10 @@ jobs:
           tool: cargo-hack,espup
           fallback: none
         if: matrix.rust == 'stable'
+      - uses: taiki-e/cache-cargo-install-action@a8b9ecf8e0c0ea09d7481cfc583a5203ecd585b5 # v3.0.5
+        with:
+          tool: bpf-linker
+        if: matrix.rust == 'nightly'
       - run: |
           retry() {
             for i in {1..10}; do

README.md

@@ -19,7 +19,7 @@ This crate provides a way to soundly perform such operations.
 
 ## Platform Support
 
-Currently, all CPU architectures supported by Rust (x86, x86_64, Arm, AArch64, Arm64EC, RISC-V, LoongArch, s390x, PowerPC, MIPS, SPARC, AVR, MSP430, Hexagon, M68k, C-SKY, and Xtensa) are supported.
+Currently, all CPU architectures supported by Rust (x86, x86_64, Arm, AArch64, Arm64EC, RISC-V, LoongArch, s390x, PowerPC, MIPS, SPARC, AVR, MSP430, Hexagon, M68k, C-SKY, and Xtensa) and BPF are supported.
 (You can use `cfg_{has,no}_*` macros to write code based on which primitive sizes are available for the current target and Rust version.)
 
 | target_arch                                 | primitives                                          | load/store | swap/CAS |
@@ -53,6 +53,8 @@ Currently, all CPU architectures supported by Rust (x86, x86_64, Arm, AArch64, A
 | m68k (+isa-68020) \[9] \[13] (experimental) | i64,u64                                             | ✓          | ✓        |
 | csky \[13] (experimental)                   | isize,usize,i8,u8,i16,u16,i32,u32                   | ✓          | ✓\[1]    |
 | xtensa \[13] (experimental)                 | isize,usize,i8,u8,i16,u16,i32,u32                   | ✓          | ✓\[1]    |
+| bpf \[13] (experimental)                    | isize,usize,i64,u64                                 | ✓          | ✓        |
+| bpf (+alu32) \[13] \[14] (experimental)     | i32,u32                                             | ✓          | ✓        |
 
 \[1] Arm's RMW operations are not available on Armv6-M (thumbv6m). RISC-V's RMW operations are not available on targets without the A (or G which means IMAFD) or Zalrsc or Zacas extension, such as riscv32i, riscv32imc, etc. 32-bit SPARC's RMW operations requires `v9` or `leoncasa` target feature (enabled by default on Linux). M68k's atomic RMW operations requires target-cpu M68020+ (enabled by default on Linux). C-SKY's atomic RMW operations requires target-cpu ck860\* or c860\* (enabled by default on the hard-float target). Xtensa's atomic RMW operations are not available on esp32s2.<br>
 \[2] Requires `cmpxchg16b` target feature (enabled by default on Apple, Windows (except Windows 7), and Fuchsia targets).<br>
@@ -65,6 +67,7 @@ Currently, all CPU architectures supported by Rust (x86, x86_64, Arm, AArch64, A
 \[11] Requires Rust 1.91+.<br>
 \[12] Requires Rust 1.95+.<br>
 \[13] Requires nightly due to `#![feature(asm_experimental_arch)]`.<br>
+\[14] Requires `alu32` target feature.<br>
 <!-- loongarch64: \[5] Requires `scq` target feature.<br> -->
 <!-- mips32r6/mips64r6: \[7] Requires Release 6 Paired LL/SC family of instructions.<br> -->
 

build.rs

@@ -122,7 +122,8 @@ fn main() {
                 }
             }
         }
-        "avr" | "m68k" | "mips" | "mips32r6" | "mips64" | "mips64r6" | "msp430" | "xtensa" => {
+        "avr" | "bpf" | "m68k" | "mips" | "mips32r6" | "mips64" | "mips64r6" | "msp430"
+        | "xtensa" => {
             if version.nightly && is_allowed_feature("asm_experimental_arch") {
                 println!("cargo:rustc-cfg=atomic_maybe_uninit_unstable_asm_experimental_arch");
             }

src/arch/README.md

@@ -8,6 +8,7 @@ This document describes the operations that are considered atomic by architectur
 - [AArch64](#aarch64)
 - [Arm](#arm)
 - [AVR](#avr)
+- [BPF](#bpf)
 - [C-SKY](#c-sky)
 - [Hexagon](#hexagon)
 - [LoongArch](#loongarch)
@@ -64,6 +65,13 @@ This architecture is always single-core and the following operations are atomic:
   disabling and restoring implementation must imply compiler fences, e.g., asm without nomem/readonly)
   may be moved out of the critical section by compiler optimizations.
 
+## BPF
+
+target_arch: bpf<br>
+Implementation: [bpf.rs](bpf.rs)<br>
+
+TODO: reference and overview
+
 ## C-SKY
 
 target_arch: csky<br>