From: Jerin Jacob Date: Tue, 3 Sep 2019 10:59:33 +0000 (+0530) Subject: bpf/arm: add basic arithmetic operations X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=111e2a747a4fde20bfcb093936efbb09dae8d4ec;p=dpdk.git bpf/arm: add basic arithmetic operations Add mov, add, sub, mul, div and mod arithmetic operations for immediate and source register variants. Signed-off-by: Jerin Jacob Acked-by: Konstantin Ananyev --- diff --git a/lib/librte_bpf/bpf_jit_arm64.c b/lib/librte_bpf/bpf_jit_arm64.c index 548408a61a..5d2ce378cc 100644 --- a/lib/librte_bpf/bpf_jit_arm64.c +++ b/lib/librte_bpf/bpf_jit_arm64.c @@ -43,6 +43,17 @@ struct a64_jit_ctx { uint8_t foundcall; /* Found EBPF_CALL class code in eBPF pgm */ }; +static int +check_mov_hw(bool is64, const uint8_t val) +{ + if (val == 16 || val == 0) + return 0; + else if (is64 && val != 64 && val != 48 && val != 32) + return 1; + + return 0; +} + static int check_reg(uint8_t r) { @@ -169,6 +180,179 @@ emit_stack_pop(struct a64_jit_ctx *ctx, uint8_t rt, uint8_t rt2) emit_ls_pair_64(ctx, rt, rt2, A64_SP, 0, 1, 0); } +#define A64_MOVN 0 +#define A64_MOVZ 2 +#define A64_MOVK 3 +static void +mov_imm(struct a64_jit_ctx *ctx, bool is64, uint8_t rd, uint8_t type, + uint16_t imm16, uint8_t shift) +{ + uint32_t insn; + + insn = (!!is64) << 31; + insn |= type << 29; + insn |= 0x25 << 23; + insn |= (shift/16) << 21; + insn |= imm16 << 5; + insn |= rd; + + emit_insn(ctx, insn, check_reg(rd) || check_mov_hw(is64, shift)); +} + +static void +emit_mov_imm32(struct a64_jit_ctx *ctx, bool is64, uint8_t rd, uint32_t val) +{ + uint16_t upper = val >> 16; + uint16_t lower = val & 0xffff; + + /* Positive number */ + if ((val & 1UL << 31) == 0) { + mov_imm(ctx, is64, rd, A64_MOVZ, lower, 0); + if (upper) + mov_imm(ctx, is64, rd, A64_MOVK, upper, 16); + } else { /* Negative number */ + if (upper == 0xffff) { + mov_imm(ctx, is64, rd, A64_MOVN, ~lower, 0); + } else { + mov_imm(ctx, is64, rd, A64_MOVN, ~upper, 16); + if (lower != 0xffff) + mov_imm(ctx, is64, rd, A64_MOVK, lower, 0); + } + } +} + +static int +u16_blocks_weight(const uint64_t val, bool one) +{ + return (((val >> 0) & 0xffff) == (one ? 0xffff : 0x0000)) + + (((val >> 16) & 0xffff) == (one ? 0xffff : 0x0000)) + + (((val >> 32) & 0xffff) == (one ? 0xffff : 0x0000)) + + (((val >> 48) & 0xffff) == (one ? 0xffff : 0x0000)); +} + +static void +emit_mov_imm(struct a64_jit_ctx *ctx, bool is64, uint8_t rd, uint64_t val) +{ + uint64_t nval = ~val; + int movn, sr; + + if (is64 == 0) + return emit_mov_imm32(ctx, 0, rd, (uint32_t)(val & 0xffffffff)); + + /* Find MOVN or MOVZ first */ + movn = u16_blocks_weight(val, true) > u16_blocks_weight(val, false); + /* Find shift right value */ + sr = movn ? rte_fls_u64(nval) - 1 : rte_fls_u64(val) - 1; + sr = RTE_ALIGN_FLOOR(sr, 16); + sr = RTE_MAX(sr, 0); + + if (movn) + mov_imm(ctx, 1, rd, A64_MOVN, (nval >> sr) & 0xffff, sr); + else + mov_imm(ctx, 1, rd, A64_MOVZ, (val >> sr) & 0xffff, sr); + + sr -= 16; + while (sr >= 0) { + if (((val >> sr) & 0xffff) != (movn ? 0xffff : 0x0000)) + mov_imm(ctx, 1, rd, A64_MOVK, (val >> sr) & 0xffff, sr); + sr -= 16; + } +} + +#define A64_ADD 0x58 +#define A64_SUB 0x258 +static void +emit_add_sub(struct a64_jit_ctx *ctx, bool is64, uint8_t rd, uint8_t rn, + uint8_t rm, uint16_t op) +{ + uint32_t insn; + + insn = (!!is64) << 31; + insn |= op << 21; /* shift == 0 */ + insn |= rm << 16; + insn |= rn << 5; + insn |= rd; + + emit_insn(ctx, insn, check_reg(rd) || check_reg(rm)); +} + +static void +emit_add(struct a64_jit_ctx *ctx, bool is64, uint8_t rd, uint8_t rm) +{ + emit_add_sub(ctx, is64, rd, rd, rm, A64_ADD); +} + +static void +emit_sub(struct a64_jit_ctx *ctx, bool is64, uint8_t rd, uint8_t rm) +{ + emit_add_sub(ctx, is64, rd, rd, rm, A64_SUB); +} + +static void +emit_mul(struct a64_jit_ctx *ctx, bool is64, uint8_t rd, uint8_t rm) +{ + uint32_t insn; + + insn = (!!is64) << 31; + insn |= 0xd8 << 21; + insn |= rm << 16; + insn |= A64_ZR << 10; + insn |= rd << 5; + insn |= rd; + + emit_insn(ctx, insn, check_reg(rd) || check_reg(rm)); +} + +#define A64_UDIV 0x2 +static void +emit_data_process_two_src(struct a64_jit_ctx *ctx, bool is64, uint8_t rd, + uint8_t rn, uint8_t rm, uint16_t op) + +{ + uint32_t insn; + + insn = (!!is64) << 31; + insn |= 0xd6 << 21; + insn |= rm << 16; + insn |= op << 10; + insn |= rn << 5; + insn |= rd; + + emit_insn(ctx, insn, check_reg(rd) || check_reg(rm)); +} + +static void +emit_div(struct a64_jit_ctx *ctx, bool is64, uint8_t rd, uint8_t rm) +{ + emit_data_process_two_src(ctx, is64, rd, rd, rm, A64_UDIV); +} + +static void +emit_msub(struct a64_jit_ctx *ctx, bool is64, uint8_t rd, uint8_t rn, + uint8_t rm, uint8_t ra) +{ + uint32_t insn; + + insn = (!!is64) << 31; + insn |= 0xd8 << 21; + insn |= rm << 16; + insn |= 0x1 << 15; + insn |= ra << 10; + insn |= rn << 5; + insn |= rd; + + emit_insn(ctx, insn, check_reg(rd) || check_reg(rn) || check_reg(rm) || + check_reg(ra)); +} + +static void +emit_mod(struct a64_jit_ctx *ctx, bool is64, uint8_t tmp, uint8_t rd, + uint8_t rm) +{ + emit_data_process_two_src(ctx, is64, tmp, rd, rm, A64_UDIV); + emit_msub(ctx, is64, rd, tmp, rm, rd); +} + static uint8_t ebpf_to_a64_reg(struct a64_jit_ctx *ctx, uint8_t reg) { @@ -365,6 +549,44 @@ emit_epilogue(struct a64_jit_ctx *ctx) emit_epilogue_no_call(ctx); } +static void +emit_cbnz(struct a64_jit_ctx *ctx, bool is64, uint8_t rt, int32_t imm19) +{ + uint32_t insn, imm; + + imm = mask_imm(19, imm19); + insn = (!!is64) << 31; + insn |= 0x35 << 24; + insn |= imm << 5; + insn |= rt; + + emit_insn(ctx, insn, check_reg(rt) || check_imm(19, imm19)); +} + +static void +emit_b(struct a64_jit_ctx *ctx, int32_t imm26) +{ + uint32_t insn, imm; + + imm = mask_imm(26, imm26); + insn = 0x5 << 26; + insn |= imm; + + emit_insn(ctx, insn, check_imm(26, imm26)); +} + +static void +emit_return_zero_if_src_zero(struct a64_jit_ctx *ctx, bool is64, uint8_t src) +{ + uint8_t r0 = ebpf_to_a64_reg(ctx, EBPF_REG_0); + uint16_t jump_to_epilogue; + + emit_cbnz(ctx, is64, src, 3); + emit_mov_imm(ctx, is64, r0, 0); + jump_to_epilogue = (ctx->program_start + ctx->program_sz) - ctx->idx; + emit_b(ctx, jump_to_epilogue); +} + static void check_program_has_call(struct a64_jit_ctx *ctx, struct rte_bpf *bpf) { @@ -391,15 +613,19 @@ check_program_has_call(struct a64_jit_ctx *ctx, struct rte_bpf *bpf) static int emit(struct a64_jit_ctx *ctx, struct rte_bpf *bpf) { - uint8_t op; + uint8_t op, dst, src, tmp1, tmp2; const struct ebpf_insn *ins; + int32_t imm; uint32_t i; + bool is64; int rc; /* Reset context fields */ ctx->idx = 0; /* arm64 SP must be aligned to 16 */ ctx->stack_sz = RTE_ALIGN_MUL_CEIL(bpf->stack_sz, 16); + tmp1 = ebpf_to_a64_reg(ctx, TMP_REG_1); + tmp2 = ebpf_to_a64_reg(ctx, TMP_REG_2); emit_prologue(ctx); @@ -407,8 +633,80 @@ emit(struct a64_jit_ctx *ctx, struct rte_bpf *bpf) ins = bpf->prm.ins + i; op = ins->code; + imm = ins->imm; + + dst = ebpf_to_a64_reg(ctx, ins->dst_reg); + src = ebpf_to_a64_reg(ctx, ins->src_reg); + is64 = (BPF_CLASS(op) == EBPF_ALU64); switch (op) { + /* dst = src */ + case (BPF_ALU | EBPF_MOV | BPF_X): + case (EBPF_ALU64 | EBPF_MOV | BPF_X): + emit_mov(ctx, is64, dst, src); + break; + /* dst = imm */ + case (BPF_ALU | EBPF_MOV | BPF_K): + case (EBPF_ALU64 | EBPF_MOV | BPF_K): + emit_mov_imm(ctx, is64, dst, imm); + break; + /* dst += src */ + case (BPF_ALU | BPF_ADD | BPF_X): + case (EBPF_ALU64 | BPF_ADD | BPF_X): + emit_add(ctx, is64, dst, src); + break; + /* dst += imm */ + case (BPF_ALU | BPF_ADD | BPF_K): + case (EBPF_ALU64 | BPF_ADD | BPF_K): + emit_mov_imm(ctx, is64, tmp1, imm); + emit_add(ctx, is64, dst, tmp1); + break; + /* dst -= src */ + case (BPF_ALU | BPF_SUB | BPF_X): + case (EBPF_ALU64 | BPF_SUB | BPF_X): + emit_sub(ctx, is64, dst, src); + break; + /* dst -= imm */ + case (BPF_ALU | BPF_SUB | BPF_K): + case (EBPF_ALU64 | BPF_SUB | BPF_K): + emit_mov_imm(ctx, is64, tmp1, imm); + emit_sub(ctx, is64, dst, tmp1); + break; + /* dst *= src */ + case (BPF_ALU | BPF_MUL | BPF_X): + case (EBPF_ALU64 | BPF_MUL | BPF_X): + emit_mul(ctx, is64, dst, src); + break; + /* dst *= imm */ + case (BPF_ALU | BPF_MUL | BPF_K): + case (EBPF_ALU64 | BPF_MUL | BPF_K): + emit_mov_imm(ctx, is64, tmp1, imm); + emit_mul(ctx, is64, dst, tmp1); + break; + /* dst /= src */ + case (BPF_ALU | BPF_DIV | BPF_X): + case (EBPF_ALU64 | BPF_DIV | BPF_X): + emit_return_zero_if_src_zero(ctx, is64, src); + emit_div(ctx, is64, dst, src); + break; + /* dst /= imm */ + case (BPF_ALU | BPF_DIV | BPF_K): + case (EBPF_ALU64 | BPF_DIV | BPF_K): + emit_mov_imm(ctx, is64, tmp1, imm); + emit_div(ctx, is64, dst, tmp1); + break; + /* dst %= src */ + case (BPF_ALU | BPF_MOD | BPF_X): + case (EBPF_ALU64 | BPF_MOD | BPF_X): + emit_return_zero_if_src_zero(ctx, is64, src); + emit_mod(ctx, is64, tmp1, dst, src); + break; + /* dst %= imm */ + case (BPF_ALU | BPF_MOD | BPF_K): + case (EBPF_ALU64 | BPF_MOD | BPF_K): + emit_mov_imm(ctx, is64, tmp1, imm); + emit_mod(ctx, is64, tmp2, dst, tmp1); + break; /* Return r0 */ case (BPF_JMP | EBPF_EXIT): emit_epilogue(ctx);