From 118ae46b794271ebcfcc9bab95e1c766198c8209 Mon Sep 17 00:00:00 2001 From: Andrea Parri Date: Wed, 7 May 2025 03:42:55 +0000 Subject: [PATCH] bpf, riscv64: Introduce emit_load_*() and emit_store_*() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit We're planning to add support for the load-acquire and store-release BPF instructions. Define emit_load_() and emit_store_() to enable/facilitate the (re)use of their code. Acked-by: Björn Töpel Reviewed-by: Pu Lehui Tested-by: Björn Töpel # QEMU/RVA23 Tested-by: Peilin Ye Signed-off-by: Andrea Parri [yepeilin@google.com: cosmetic change to commit title] Signed-off-by: Peilin Ye Link: https://lore.kernel.org/r/fce89473a5748e1631d18a5917d953460d1ae0d0.1746588351.git.yepeilin@google.com Signed-off-by: Alexei Starovoitov --- arch/riscv/net/bpf_jit_comp64.c | 242 +++++++++++++++++++------------- 1 file changed, 143 insertions(+), 99 deletions(-) diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c index ca60db75199d..953b6a20c69f 100644 --- a/arch/riscv/net/bpf_jit_comp64.c +++ b/arch/riscv/net/bpf_jit_comp64.c @@ -473,6 +473,140 @@ static inline void emit_kcfi(u32 hash, struct rv_jit_context *ctx) emit(hash, ctx); } +static int emit_load_8(bool sign_ext, u8 rd, s32 off, u8 rs, struct rv_jit_context *ctx) +{ + int insns_start; + + if (is_12b_int(off)) { + insns_start = ctx->ninsns; + if (sign_ext) + emit(rv_lb(rd, off, rs), ctx); + else + emit(rv_lbu(rd, off, rs), ctx); + return ctx->ninsns - insns_start; + } + + emit_imm(RV_REG_T1, off, ctx); + emit_add(RV_REG_T1, RV_REG_T1, rs, ctx); + insns_start = ctx->ninsns; + if (sign_ext) + emit(rv_lb(rd, 0, RV_REG_T1), ctx); + else + emit(rv_lbu(rd, 0, RV_REG_T1), ctx); + return ctx->ninsns - insns_start; +} + +static int emit_load_16(bool sign_ext, u8 rd, s32 off, u8 rs, struct rv_jit_context *ctx) +{ + int insns_start; + + if (is_12b_int(off)) { + insns_start = ctx->ninsns; + if (sign_ext) + emit(rv_lh(rd, off, rs), ctx); + else + emit(rv_lhu(rd, off, rs), ctx); + return ctx->ninsns - insns_start; + } + + emit_imm(RV_REG_T1, off, ctx); + emit_add(RV_REG_T1, RV_REG_T1, rs, ctx); + insns_start = ctx->ninsns; + if (sign_ext) + emit(rv_lh(rd, 0, RV_REG_T1), ctx); + else + emit(rv_lhu(rd, 0, RV_REG_T1), ctx); + return ctx->ninsns - insns_start; +} + +static int emit_load_32(bool sign_ext, u8 rd, s32 off, u8 rs, struct rv_jit_context *ctx) +{ + int insns_start; + + if (is_12b_int(off)) { + insns_start = ctx->ninsns; + if (sign_ext) + emit(rv_lw(rd, off, rs), ctx); + else + emit(rv_lwu(rd, off, rs), ctx); + return ctx->ninsns - insns_start; + } + + emit_imm(RV_REG_T1, off, ctx); + emit_add(RV_REG_T1, RV_REG_T1, rs, ctx); + insns_start = ctx->ninsns; + if (sign_ext) + emit(rv_lw(rd, 0, RV_REG_T1), ctx); + else + emit(rv_lwu(rd, 0, RV_REG_T1), ctx); + return ctx->ninsns - insns_start; +} + +static int emit_load_64(bool sign_ext, u8 rd, s32 off, u8 rs, struct rv_jit_context *ctx) +{ + int insns_start; + + if (is_12b_int(off)) { + insns_start = ctx->ninsns; + emit_ld(rd, off, rs, ctx); + return ctx->ninsns - insns_start; + } + + emit_imm(RV_REG_T1, off, ctx); + emit_add(RV_REG_T1, RV_REG_T1, rs, ctx); + insns_start = ctx->ninsns; + emit_ld(rd, 0, RV_REG_T1, ctx); + return ctx->ninsns - insns_start; +} + +static void emit_store_8(u8 rd, s32 off, u8 rs, struct rv_jit_context *ctx) +{ + if (is_12b_int(off)) { + emit(rv_sb(rd, off, rs), ctx); + return; + } + + emit_imm(RV_REG_T1, off, ctx); + emit_add(RV_REG_T1, RV_REG_T1, rd, ctx); + emit(rv_sb(RV_REG_T1, 0, rs), ctx); +} + +static void emit_store_16(u8 rd, s32 off, u8 rs, struct rv_jit_context *ctx) +{ + if (is_12b_int(off)) { + emit(rv_sh(rd, off, rs), ctx); + return; + } + + emit_imm(RV_REG_T1, off, ctx); + emit_add(RV_REG_T1, RV_REG_T1, rd, ctx); + emit(rv_sh(RV_REG_T1, 0, rs), ctx); +} + +static void emit_store_32(u8 rd, s32 off, u8 rs, struct rv_jit_context *ctx) +{ + if (is_12b_int(off)) { + emit_sw(rd, off, rs, ctx); + return; + } + + emit_imm(RV_REG_T1, off, ctx); + emit_add(RV_REG_T1, RV_REG_T1, rd, ctx); + emit_sw(RV_REG_T1, 0, rs, ctx); +} + +static void emit_store_64(u8 rd, s32 off, u8 rs, struct rv_jit_context *ctx) +{ + if (is_12b_int(off)) { + emit_sd(rd, off, rs, ctx); + return; + } + + emit_imm(RV_REG_T1, off, ctx); + emit_add(RV_REG_T1, RV_REG_T1, rd, ctx); + emit_sd(RV_REG_T1, 0, rs, ctx); +} + static void emit_atomic(u8 rd, u8 rs, s16 off, s32 imm, bool is64, struct rv_jit_context *ctx) { @@ -1650,8 +1784,8 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, case BPF_LDX | BPF_PROBE_MEM32 | BPF_W: case BPF_LDX | BPF_PROBE_MEM32 | BPF_DW: { - int insn_len, insns_start; bool sign_ext; + int insn_len; sign_ext = BPF_MODE(insn->code) == BPF_MEMSX || BPF_MODE(insn->code) == BPF_PROBE_MEMSX; @@ -1663,78 +1797,16 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, switch (BPF_SIZE(code)) { case BPF_B: - if (is_12b_int(off)) { - insns_start = ctx->ninsns; - if (sign_ext) - emit(rv_lb(rd, off, rs), ctx); - else - emit(rv_lbu(rd, off, rs), ctx); - insn_len = ctx->ninsns - insns_start; - break; - } - - emit_imm(RV_REG_T1, off, ctx); - emit_add(RV_REG_T1, RV_REG_T1, rs, ctx); - insns_start = ctx->ninsns; - if (sign_ext) - emit(rv_lb(rd, 0, RV_REG_T1), ctx); - else - emit(rv_lbu(rd, 0, RV_REG_T1), ctx); - insn_len = ctx->ninsns - insns_start; + insn_len = emit_load_8(sign_ext, rd, off, rs, ctx); break; case BPF_H: - if (is_12b_int(off)) { - insns_start = ctx->ninsns; - if (sign_ext) - emit(rv_lh(rd, off, rs), ctx); - else - emit(rv_lhu(rd, off, rs), ctx); - insn_len = ctx->ninsns - insns_start; - break; - } - - emit_imm(RV_REG_T1, off, ctx); - emit_add(RV_REG_T1, RV_REG_T1, rs, ctx); - insns_start = ctx->ninsns; - if (sign_ext) - emit(rv_lh(rd, 0, RV_REG_T1), ctx); - else - emit(rv_lhu(rd, 0, RV_REG_T1), ctx); - insn_len = ctx->ninsns - insns_start; + insn_len = emit_load_16(sign_ext, rd, off, rs, ctx); break; case BPF_W: - if (is_12b_int(off)) { - insns_start = ctx->ninsns; - if (sign_ext) - emit(rv_lw(rd, off, rs), ctx); - else - emit(rv_lwu(rd, off, rs), ctx); - insn_len = ctx->ninsns - insns_start; - break; - } - - emit_imm(RV_REG_T1, off, ctx); - emit_add(RV_REG_T1, RV_REG_T1, rs, ctx); - insns_start = ctx->ninsns; - if (sign_ext) - emit(rv_lw(rd, 0, RV_REG_T1), ctx); - else - emit(rv_lwu(rd, 0, RV_REG_T1), ctx); - insn_len = ctx->ninsns - insns_start; + insn_len = emit_load_32(sign_ext, rd, off, rs, ctx); break; case BPF_DW: - if (is_12b_int(off)) { - insns_start = ctx->ninsns; - emit_ld(rd, off, rs, ctx); - insn_len = ctx->ninsns - insns_start; - break; - } - - emit_imm(RV_REG_T1, off, ctx); - emit_add(RV_REG_T1, RV_REG_T1, rs, ctx); - insns_start = ctx->ninsns; - emit_ld(rd, 0, RV_REG_T1, ctx); - insn_len = ctx->ninsns - insns_start; + insn_len = emit_load_64(sign_ext, rd, off, rs, ctx); break; } @@ -1879,44 +1951,16 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, /* STX: *(size *)(dst + off) = src */ case BPF_STX | BPF_MEM | BPF_B: - if (is_12b_int(off)) { - emit(rv_sb(rd, off, rs), ctx); - break; - } - - emit_imm(RV_REG_T1, off, ctx); - emit_add(RV_REG_T1, RV_REG_T1, rd, ctx); - emit(rv_sb(RV_REG_T1, 0, rs), ctx); + emit_store_8(rd, off, rs, ctx); break; case BPF_STX | BPF_MEM | BPF_H: - if (is_12b_int(off)) { - emit(rv_sh(rd, off, rs), ctx); - break; - } - - emit_imm(RV_REG_T1, off, ctx); - emit_add(RV_REG_T1, RV_REG_T1, rd, ctx); - emit(rv_sh(RV_REG_T1, 0, rs), ctx); + emit_store_16(rd, off, rs, ctx); break; case BPF_STX | BPF_MEM | BPF_W: - if (is_12b_int(off)) { - emit_sw(rd, off, rs, ctx); - break; - } - - emit_imm(RV_REG_T1, off, ctx); - emit_add(RV_REG_T1, RV_REG_T1, rd, ctx); - emit_sw(RV_REG_T1, 0, rs, ctx); + emit_store_32(rd, off, rs, ctx); break; case BPF_STX | BPF_MEM | BPF_DW: - if (is_12b_int(off)) { - emit_sd(rd, off, rs, ctx); - break; - } - - emit_imm(RV_REG_T1, off, ctx); - emit_add(RV_REG_T1, RV_REG_T1, rd, ctx); - emit_sd(RV_REG_T1, 0, rs, ctx); + emit_store_64(rd, off, rs, ctx); break; case BPF_STX | BPF_ATOMIC | BPF_W: case BPF_STX | BPF_ATOMIC | BPF_DW: -- 2.50.1