diff options
Diffstat (limited to '')
| -rw-r--r-- | arch/riscv/net/Makefile | 9 | ||||
| -rw-r--r-- | arch/riscv/net/bpf_jit.h | 1060 | ||||
| -rw-r--r-- | arch/riscv/net/bpf_jit_comp32.c | 1357 | ||||
| -rw-r--r-- | arch/riscv/net/bpf_jit_comp64.c | 1353 | ||||
| -rw-r--r-- | arch/riscv/net/bpf_jit_core.c | 206 |
5 files changed, 3985 insertions, 0 deletions
diff --git a/arch/riscv/net/Makefile b/arch/riscv/net/Makefile new file mode 100644 index 000000000..9a1e5f0a9 --- /dev/null +++ b/arch/riscv/net/Makefile @@ -0,0 +1,9 @@ +# SPDX-License-Identifier: GPL-2.0-only + +obj-$(CONFIG_BPF_JIT) += bpf_jit_core.o + +ifeq ($(CONFIG_ARCH_RV64I),y) + obj-$(CONFIG_BPF_JIT) += bpf_jit_comp64.o +else + obj-$(CONFIG_BPF_JIT) += bpf_jit_comp32.o +endif diff --git a/arch/riscv/net/bpf_jit.h b/arch/riscv/net/bpf_jit.h new file mode 100644 index 000000000..5ee21a199 --- /dev/null +++ b/arch/riscv/net/bpf_jit.h @@ -0,0 +1,1060 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Common functionality for RV32 and RV64 BPF JIT compilers + * + * Copyright (c) 2019 Björn Töpel <bjorn.topel@gmail.com> + * + */ + +#ifndef _BPF_JIT_H +#define _BPF_JIT_H + +#include <linux/bpf.h> +#include <linux/filter.h> +#include <asm/cacheflush.h> + +static inline bool rvc_enabled(void) +{ + return IS_ENABLED(CONFIG_RISCV_ISA_C); +} + +enum { + RV_REG_ZERO = 0, /* The constant value 0 */ + RV_REG_RA = 1, /* Return address */ + RV_REG_SP = 2, /* Stack pointer */ + RV_REG_GP = 3, /* Global pointer */ + RV_REG_TP = 4, /* Thread pointer */ + RV_REG_T0 = 5, /* Temporaries */ + RV_REG_T1 = 6, + RV_REG_T2 = 7, + RV_REG_FP = 8, /* Saved register/frame pointer */ + RV_REG_S1 = 9, /* Saved register */ + RV_REG_A0 = 10, /* Function argument/return values */ + RV_REG_A1 = 11, /* Function arguments */ + RV_REG_A2 = 12, + RV_REG_A3 = 13, + RV_REG_A4 = 14, + RV_REG_A5 = 15, + RV_REG_A6 = 16, + RV_REG_A7 = 17, + RV_REG_S2 = 18, /* Saved registers */ + RV_REG_S3 = 19, + RV_REG_S4 = 20, + RV_REG_S5 = 21, + RV_REG_S6 = 22, + RV_REG_S7 = 23, + RV_REG_S8 = 24, + RV_REG_S9 = 25, + RV_REG_S10 = 26, + RV_REG_S11 = 27, + RV_REG_T3 = 28, /* Temporaries */ + RV_REG_T4 = 29, + RV_REG_T5 = 30, + RV_REG_T6 = 31, +}; + +static inline bool is_creg(u8 reg) +{ + return (1 << reg) & (BIT(RV_REG_FP) | + BIT(RV_REG_S1) | + BIT(RV_REG_A0) | + BIT(RV_REG_A1) | + BIT(RV_REG_A2) | + BIT(RV_REG_A3) | + BIT(RV_REG_A4) | + BIT(RV_REG_A5)); +} + +struct rv_jit_context { + struct bpf_prog *prog; + u16 *insns; /* RV insns */ + int ninsns; + int prologue_len; + int epilogue_offset; + int *offset; /* BPF to RV */ + int nexentries; + unsigned long flags; + int stack_size; +}; + +/* Convert from ninsns to bytes. */ +static inline int ninsns_rvoff(int ninsns) +{ + return ninsns << 1; +} + +struct rv_jit_data { + struct bpf_binary_header *header; + u8 *image; + struct rv_jit_context ctx; +}; + +static inline void bpf_fill_ill_insns(void *area, unsigned int size) +{ + memset(area, 0, size); +} + +static inline void bpf_flush_icache(void *start, void *end) +{ + flush_icache_range((unsigned long)start, (unsigned long)end); +} + +/* Emit a 4-byte riscv instruction. */ +static inline void emit(const u32 insn, struct rv_jit_context *ctx) +{ + if (ctx->insns) { + ctx->insns[ctx->ninsns] = insn; + ctx->insns[ctx->ninsns + 1] = (insn >> 16); + } + + ctx->ninsns += 2; +} + +/* Emit a 2-byte riscv compressed instruction. */ +static inline void emitc(const u16 insn, struct rv_jit_context *ctx) +{ + BUILD_BUG_ON(!rvc_enabled()); + + if (ctx->insns) + ctx->insns[ctx->ninsns] = insn; + + ctx->ninsns++; +} + +static inline int epilogue_offset(struct rv_jit_context *ctx) +{ + int to = ctx->epilogue_offset, from = ctx->ninsns; + + return ninsns_rvoff(to - from); +} + +/* Return -1 or inverted cond. */ +static inline int invert_bpf_cond(u8 cond) +{ + switch (cond) { + case BPF_JEQ: + return BPF_JNE; + case BPF_JGT: + return BPF_JLE; + case BPF_JLT: + return BPF_JGE; + case BPF_JGE: + return BPF_JLT; + case BPF_JLE: + return BPF_JGT; + case BPF_JNE: + return BPF_JEQ; + case BPF_JSGT: + return BPF_JSLE; + case BPF_JSLT: + return BPF_JSGE; + case BPF_JSGE: + return BPF_JSLT; + case BPF_JSLE: + return BPF_JSGT; + } + return -1; +} + +static inline bool is_6b_int(long val) +{ + return -(1L << 5) <= val && val < (1L << 5); +} + +static inline bool is_7b_uint(unsigned long val) +{ + return val < (1UL << 7); +} + +static inline bool is_8b_uint(unsigned long val) +{ + return val < (1UL << 8); +} + +static inline bool is_9b_uint(unsigned long val) +{ + return val < (1UL << 9); +} + +static inline bool is_10b_int(long val) +{ + return -(1L << 9) <= val && val < (1L << 9); +} + +static inline bool is_10b_uint(unsigned long val) +{ + return val < (1UL << 10); +} + +static inline bool is_12b_int(long val) +{ + return -(1L << 11) <= val && val < (1L << 11); +} + +static inline int is_12b_check(int off, int insn) +{ + if (!is_12b_int(off)) { + pr_err("bpf-jit: insn=%d 12b < offset=%d not supported yet!\n", + insn, (int)off); + return -1; + } + return 0; +} + +static inline bool is_13b_int(long val) +{ + return -(1L << 12) <= val && val < (1L << 12); +} + +static inline bool is_21b_int(long val) +{ + return -(1L << 20) <= val && val < (1L << 20); +} + +static inline int rv_offset(int insn, int off, struct rv_jit_context *ctx) +{ + int from, to; + + off++; /* BPF branch is from PC+1, RV is from PC */ + from = (insn > 0) ? ctx->offset[insn - 1] : ctx->prologue_len; + to = (insn + off > 0) ? ctx->offset[insn + off - 1] : ctx->prologue_len; + return ninsns_rvoff(to - from); +} + +/* Instruction formats. */ + +static inline u32 rv_r_insn(u8 funct7, u8 rs2, u8 rs1, u8 funct3, u8 rd, + u8 opcode) +{ + return (funct7 << 25) | (rs2 << 20) | (rs1 << 15) | (funct3 << 12) | + (rd << 7) | opcode; +} + +static inline u32 rv_i_insn(u16 imm11_0, u8 rs1, u8 funct3, u8 rd, u8 opcode) +{ + return (imm11_0 << 20) | (rs1 << 15) | (funct3 << 12) | (rd << 7) | + opcode; +} + +static inline u32 rv_s_insn(u16 imm11_0, u8 rs2, u8 rs1, u8 funct3, u8 opcode) +{ + u8 imm11_5 = imm11_0 >> 5, imm4_0 = imm11_0 & 0x1f; + + return (imm11_5 << 25) | (rs2 << 20) | (rs1 << 15) | (funct3 << 12) | + (imm4_0 << 7) | opcode; +} + +static inline u32 rv_b_insn(u16 imm12_1, u8 rs2, u8 rs1, u8 funct3, u8 opcode) +{ + u8 imm12 = ((imm12_1 & 0x800) >> 5) | ((imm12_1 & 0x3f0) >> 4); + u8 imm4_1 = ((imm12_1 & 0xf) << 1) | ((imm12_1 & 0x400) >> 10); + + return (imm12 << 25) | (rs2 << 20) | (rs1 << 15) | (funct3 << 12) | + (imm4_1 << 7) | opcode; +} + +static inline u32 rv_u_insn(u32 imm31_12, u8 rd, u8 opcode) +{ + return (imm31_12 << 12) | (rd << 7) | opcode; +} + +static inline u32 rv_j_insn(u32 imm20_1, u8 rd, u8 opcode) +{ + u32 imm; + + imm = (imm20_1 & 0x80000) | ((imm20_1 & 0x3ff) << 9) | + ((imm20_1 & 0x400) >> 2) | ((imm20_1 & 0x7f800) >> 11); + + return (imm << 12) | (rd << 7) | opcode; +} + +static inline u32 rv_amo_insn(u8 funct5, u8 aq, u8 rl, u8 rs2, u8 rs1, + u8 funct3, u8 rd, u8 opcode) +{ + u8 funct7 = (funct5 << 2) | (aq << 1) | rl; + + return rv_r_insn(funct7, rs2, rs1, funct3, rd, opcode); +} + +/* RISC-V compressed instruction formats. */ + +static inline u16 rv_cr_insn(u8 funct4, u8 rd, u8 rs2, u8 op) +{ + return (funct4 << 12) | (rd << 7) | (rs2 << 2) | op; +} + +static inline u16 rv_ci_insn(u8 funct3, u32 imm6, u8 rd, u8 op) +{ + u32 imm; + + imm = ((imm6 & 0x20) << 7) | ((imm6 & 0x1f) << 2); + return (funct3 << 13) | (rd << 7) | op | imm; +} + +static inline u16 rv_css_insn(u8 funct3, u32 uimm, u8 rs2, u8 op) +{ + return (funct3 << 13) | (uimm << 7) | (rs2 << 2) | op; +} + +static inline u16 rv_ciw_insn(u8 funct3, u32 uimm, u8 rd, u8 op) +{ + return (funct3 << 13) | (uimm << 5) | ((rd & 0x7) << 2) | op; +} + +static inline u16 rv_cl_insn(u8 funct3, u32 imm_hi, u8 rs1, u32 imm_lo, u8 rd, + u8 op) +{ + return (funct3 << 13) | (imm_hi << 10) | ((rs1 & 0x7) << 7) | + (imm_lo << 5) | ((rd & 0x7) << 2) | op; +} + +static inline u16 rv_cs_insn(u8 funct3, u32 imm_hi, u8 rs1, u32 imm_lo, u8 rs2, + u8 op) +{ + return (funct3 << 13) | (imm_hi << 10) | ((rs1 & 0x7) << 7) | + (imm_lo << 5) | ((rs2 & 0x7) << 2) | op; +} + +static inline u16 rv_ca_insn(u8 funct6, u8 rd, u8 funct2, u8 rs2, u8 op) +{ + return (funct6 << 10) | ((rd & 0x7) << 7) | (funct2 << 5) | + ((rs2 & 0x7) << 2) | op; +} + +static inline u16 rv_cb_insn(u8 funct3, u32 imm6, u8 funct2, u8 rd, u8 op) +{ + u32 imm; + + imm = ((imm6 & 0x20) << 7) | ((imm6 & 0x1f) << 2); + return (funct3 << 13) | (funct2 << 10) | ((rd & 0x7) << 7) | op | imm; +} + +/* Instructions shared by both RV32 and RV64. */ + +static inline u32 rv_addi(u8 rd, u8 rs1, u16 imm11_0) +{ + return rv_i_insn(imm11_0, rs1, 0, rd, 0x13); +} + +static inline u32 rv_andi(u8 rd, u8 rs1, u16 imm11_0) +{ + return rv_i_insn(imm11_0, rs1, 7, rd, 0x13); +} + +static inline u32 rv_ori(u8 rd, u8 rs1, u16 imm11_0) +{ + return rv_i_insn(imm11_0, rs1, 6, rd, 0x13); +} + +static inline u32 rv_xori(u8 rd, u8 rs1, u16 imm11_0) +{ + return rv_i_insn(imm11_0, rs1, 4, rd, 0x13); +} + +static inline u32 rv_slli(u8 rd, u8 rs1, u16 imm11_0) +{ + return rv_i_insn(imm11_0, rs1, 1, rd, 0x13); +} + +static inline u32 rv_srli(u8 rd, u8 rs1, u16 imm11_0) +{ + return rv_i_insn(imm11_0, rs1, 5, rd, 0x13); +} + +static inline u32 rv_srai(u8 rd, u8 rs1, u16 imm11_0) +{ + return rv_i_insn(0x400 | imm11_0, rs1, 5, rd, 0x13); +} + +static inline u32 rv_lui(u8 rd, u32 imm31_12) +{ + return rv_u_insn(imm31_12, rd, 0x37); +} + +static inline u32 rv_auipc(u8 rd, u32 imm31_12) +{ + return rv_u_insn(imm31_12, rd, 0x17); +} + +static inline u32 rv_add(u8 rd, u8 rs1, u8 rs2) +{ + return rv_r_insn(0, rs2, rs1, 0, rd, 0x33); +} + +static inline u32 rv_sub(u8 rd, u8 rs1, u8 rs2) +{ + return rv_r_insn(0x20, rs2, rs1, 0, rd, 0x33); +} + +static inline u32 rv_sltu(u8 rd, u8 rs1, u8 rs2) +{ + return rv_r_insn(0, rs2, rs1, 3, rd, 0x33); +} + +static inline u32 rv_and(u8 rd, u8 rs1, u8 rs2) +{ + return rv_r_insn(0, rs2, rs1, 7, rd, 0x33); +} + +static inline u32 rv_or(u8 rd, u8 rs1, u8 rs2) +{ + return rv_r_insn(0, rs2, rs1, 6, rd, 0x33); +} + +static inline u32 rv_xor(u8 rd, u8 rs1, u8 rs2) +{ + return rv_r_insn(0, rs2, rs1, 4, rd, 0x33); +} + +static inline u32 rv_sll(u8 rd, u8 rs1, u8 rs2) +{ + return rv_r_insn(0, rs2, rs1, 1, rd, 0x33); +} + +static inline u32 rv_srl(u8 rd, u8 rs1, u8 rs2) +{ + return rv_r_insn(0, rs2, rs1, 5, rd, 0x33); +} + +static inline u32 rv_sra(u8 rd, u8 rs1, u8 rs2) +{ + return rv_r_insn(0x20, rs2, rs1, 5, rd, 0x33); +} + +static inline u32 rv_mul(u8 rd, u8 rs1, u8 rs2) +{ + return rv_r_insn(1, rs2, rs1, 0, rd, 0x33); +} + +static inline u32 rv_mulhu(u8 rd, u8 rs1, u8 rs2) +{ + return rv_r_insn(1, rs2, rs1, 3, rd, 0x33); +} + +static inline u32 rv_divu(u8 rd, u8 rs1, u8 rs2) +{ + return rv_r_insn(1, rs2, rs1, 5, rd, 0x33); +} + +static inline u32 rv_remu(u8 rd, u8 rs1, u8 rs2) +{ + return rv_r_insn(1, rs2, rs1, 7, rd, 0x33); +} + +static inline u32 rv_jal(u8 rd, u32 imm20_1) +{ + return rv_j_insn(imm20_1, rd, 0x6f); +} + +static inline u32 rv_jalr(u8 rd, u8 rs1, u16 imm11_0) +{ + return rv_i_insn(imm11_0, rs1, 0, rd, 0x67); +} + +static inline u32 rv_beq(u8 rs1, u8 rs2, u16 imm12_1) +{ + return rv_b_insn(imm12_1, rs2, rs1, 0, 0x63); +} + +static inline u32 rv_bne(u8 rs1, u8 rs2, u16 imm12_1) +{ + return rv_b_insn(imm12_1, rs2, rs1, 1, 0x63); +} + +static inline u32 rv_bltu(u8 rs1, u8 rs2, u16 imm12_1) +{ + return rv_b_insn(imm12_1, rs2, rs1, 6, 0x63); +} + +static inline u32 rv_bgtu(u8 rs1, u8 rs2, u16 imm12_1) +{ + return rv_bltu(rs2, rs1, imm12_1); +} + +static inline u32 rv_bgeu(u8 rs1, u8 rs2, u16 imm12_1) +{ + return rv_b_insn(imm12_1, rs2, rs1, 7, 0x63); +} + +static inline u32 rv_bleu(u8 rs1, u8 rs2, u16 imm12_1) +{ + return rv_bgeu(rs2, rs1, imm12_1); +} + +static inline u32 rv_blt(u8 rs1, u8 rs2, u16 imm12_1) +{ + return rv_b_insn(imm12_1, rs2, rs1, 4, 0x63); +} + +static inline u32 rv_bgt(u8 rs1, u8 rs2, u16 imm12_1) +{ + return rv_blt(rs2, rs1, imm12_1); +} + +static inline u32 rv_bge(u8 rs1, u8 rs2, u16 imm12_1) +{ + return rv_b_insn(imm12_1, rs2, rs1, 5, 0x63); +} + +static inline u32 rv_ble(u8 rs1, u8 rs2, u16 imm12_1) +{ + return rv_bge(rs2, rs1, imm12_1); +} + +static inline u32 rv_lw(u8 rd, u16 imm11_0, u8 rs1) +{ + return rv_i_insn(imm11_0, rs1, 2, rd, 0x03); +} + +static inline u32 rv_lbu(u8 rd, u16 imm11_0, u8 rs1) +{ + return rv_i_insn(imm11_0, rs1, 4, rd, 0x03); +} + +static inline u32 rv_lhu(u8 rd, u16 imm11_0, u8 rs1) +{ + return rv_i_insn(imm11_0, rs1, 5, rd, 0x03); +} + +static inline u32 rv_sb(u8 rs1, u16 imm11_0, u8 rs2) +{ + return rv_s_insn(imm11_0, rs2, rs1, 0, 0x23); +} + +static inline u32 rv_sh(u8 rs1, u16 imm11_0, u8 rs2) +{ + return rv_s_insn(imm11_0, rs2, rs1, 1, 0x23); +} + +static inline u32 rv_sw(u8 rs1, u16 imm11_0, u8 rs2) +{ + return rv_s_insn(imm11_0, rs2, rs1, 2, 0x23); +} + +static inline u32 rv_amoadd_w(u8 rd, u8 rs2, u8 rs1, u8 aq, u8 rl) +{ + return rv_amo_insn(0, aq, rl, rs2, rs1, 2, rd, 0x2f); +} + +static inline u32 rv_amoand_w(u8 rd, u8 rs2, u8 rs1, u8 aq, u8 rl) +{ + return rv_amo_insn(0xc, aq, rl, rs2, rs1, 2, rd, 0x2f); +} + +static inline u32 rv_amoor_w(u8 rd, u8 rs2, u8 rs1, u8 aq, u8 rl) +{ + return rv_amo_insn(0x8, aq, rl, rs2, rs1, 2, rd, 0x2f); +} + +static inline u32 rv_amoxor_w(u8 rd, u8 rs2, u8 rs1, u8 aq, u8 rl) +{ + return rv_amo_insn(0x4, aq, rl, rs2, rs1, 2, rd, 0x2f); +} + +static inline u32 rv_amoswap_w(u8 rd, u8 rs2, u8 rs1, u8 aq, u8 rl) +{ + return rv_amo_insn(0x1, aq, rl, rs2, rs1, 2, rd, 0x2f); +} + +static inline u32 rv_lr_w(u8 rd, u8 rs2, u8 rs1, u8 aq, u8 rl) +{ + return rv_amo_insn(0x2, aq, rl, rs2, rs1, 2, rd, 0x2f); +} + +static inline u32 rv_sc_w(u8 rd, u8 rs2, u8 rs1, u8 aq, u8 rl) +{ + return rv_amo_insn(0x3, aq, rl, rs2, rs1, 2, rd, 0x2f); +} + +static inline u32 rv_fence(u8 pred, u8 succ) +{ + u16 imm11_0 = pred << 4 | succ; + + return rv_i_insn(imm11_0, 0, 0, 0, 0xf); +} + +/* RVC instrutions. */ + +static inline u16 rvc_addi4spn(u8 rd, u32 imm10) +{ + u32 imm; + + imm = ((imm10 & 0x30) << 2) | ((imm10 & 0x3c0) >> 4) | + ((imm10 & 0x4) >> 1) | ((imm10 & 0x8) >> 3); + return rv_ciw_insn(0x0, imm, rd, 0x0); +} + +static inline u16 rvc_lw(u8 rd, u32 imm7, u8 rs1) +{ + u32 imm_hi, imm_lo; + + imm_hi = (imm7 & 0x38) >> 3; + imm_lo = ((imm7 & 0x4) >> 1) | ((imm7 & 0x40) >> 6); + return rv_cl_insn(0x2, imm_hi, rs1, imm_lo, rd, 0x0); +} + +static inline u16 rvc_sw(u8 rs1, u32 imm7, u8 rs2) +{ + u32 imm_hi, imm_lo; + + imm_hi = (imm7 & 0x38) >> 3; + imm_lo = ((imm7 & 0x4) >> 1) | ((imm7 & 0x40) >> 6); + return rv_cs_insn(0x6, imm_hi, rs1, imm_lo, rs2, 0x0); +} + +static inline u16 rvc_addi(u8 rd, u32 imm6) +{ + return rv_ci_insn(0, imm6, rd, 0x1); +} + +static inline u16 rvc_li(u8 rd, u32 imm6) +{ + return rv_ci_insn(0x2, imm6, rd, 0x1); +} + +static inline u16 rvc_addi16sp(u32 imm10) +{ + u32 imm; + + imm = ((imm10 & 0x200) >> 4) | (imm10 & 0x10) | ((imm10 & 0x40) >> 3) | + ((imm10 & 0x180) >> 6) | ((imm10 & 0x20) >> 5); + return rv_ci_insn(0x3, imm, RV_REG_SP, 0x1); +} + +static inline u16 rvc_lui(u8 rd, u32 imm6) +{ + return rv_ci_insn(0x3, imm6, rd, 0x1); +} + +static inline u16 rvc_srli(u8 rd, u32 imm6) +{ + return rv_cb_insn(0x4, imm6, 0, rd, 0x1); +} + +static inline u16 rvc_srai(u8 rd, u32 imm6) +{ + return rv_cb_insn(0x4, imm6, 0x1, rd, 0x1); +} + +static inline u16 rvc_andi(u8 rd, u32 imm6) +{ + return rv_cb_insn(0x4, imm6, 0x2, rd, 0x1); +} + +static inline u16 rvc_sub(u8 rd, u8 rs) +{ + return rv_ca_insn(0x23, rd, 0, rs, 0x1); +} + +static inline u16 rvc_xor(u8 rd, u8 rs) +{ + return rv_ca_insn(0x23, rd, 0x1, rs, 0x1); +} + +static inline u16 rvc_or(u8 rd, u8 rs) +{ + return rv_ca_insn(0x23, rd, 0x2, rs, 0x1); +} + +static inline u16 rvc_and(u8 rd, u8 rs) +{ + return rv_ca_insn(0x23, rd, 0x3, rs, 0x1); +} + +static inline u16 rvc_slli(u8 rd, u32 imm6) +{ + return rv_ci_insn(0, imm6, rd, 0x2); +} + +static inline u16 rvc_lwsp(u8 rd, u32 imm8) +{ + u32 imm; + + imm = ((imm8 & 0xc0) >> 6) | (imm8 & 0x3c); + return rv_ci_insn(0x2, imm, rd, 0x2); +} + +static inline u16 rvc_jr(u8 rs1) +{ + return rv_cr_insn(0x8, rs1, RV_REG_ZERO, 0x2); +} + +static inline u16 rvc_mv(u8 rd, u8 rs) +{ + return rv_cr_insn(0x8, rd, rs, 0x2); +} + +static inline u16 rvc_jalr(u8 rs1) +{ + return rv_cr_insn(0x9, rs1, RV_REG_ZERO, 0x2); +} + +static inline u16 rvc_add(u8 rd, u8 rs) +{ + return rv_cr_insn(0x9, rd, rs, 0x2); +} + +static inline u16 rvc_swsp(u32 imm8, u8 rs2) +{ + u32 imm; + + imm = (imm8 & 0x3c) | ((imm8 & 0xc0) >> 6); + return rv_css_insn(0x6, imm, rs2, 0x2); +} + +/* + * RV64-only instructions. + * + * These instructions are not available on RV32. Wrap them below a #if to + * ensure that the RV32 JIT doesn't emit any of these instructions. + */ + +#if __riscv_xlen == 64 + +static inline u32 rv_addiw(u8 rd, u8 rs1, u16 imm11_0) +{ + return rv_i_insn(imm11_0, rs1, 0, rd, 0x1b); +} + +static inline u32 rv_slliw(u8 rd, u8 rs1, u16 imm11_0) +{ + return rv_i_insn(imm11_0, rs1, 1, rd, 0x1b); +} + +static inline u32 rv_srliw(u8 rd, u8 rs1, u16 imm11_0) +{ + return rv_i_insn(imm11_0, rs1, 5, rd, 0x1b); +} + +static inline u32 rv_sraiw(u8 rd, u8 rs1, u16 imm11_0) +{ + return rv_i_insn(0x400 | imm11_0, rs1, 5, rd, 0x1b); +} + +static inline u32 rv_addw(u8 rd, u8 rs1, u8 rs2) +{ + return rv_r_insn(0, rs2, rs1, 0, rd, 0x3b); +} + +static inline u32 rv_subw(u8 rd, u8 rs1, u8 rs2) +{ + return rv_r_insn(0x20, rs2, rs1, 0, rd, 0x3b); +} + +static inline u32 rv_sllw(u8 rd, u8 rs1, u8 rs2) +{ + return rv_r_insn(0, rs2, rs1, 1, rd, 0x3b); +} + +static inline u32 rv_srlw(u8 rd, u8 rs1, u8 rs2) +{ + return rv_r_insn(0, rs2, rs1, 5, rd, 0x3b); +} + +static inline u32 rv_sraw(u8 rd, u8 rs1, u8 rs2) +{ + return rv_r_insn(0x20, rs2, rs1, 5, rd, 0x3b); +} + +static inline u32 rv_mulw(u8 rd, u8 rs1, u8 rs2) +{ + return rv_r_insn(1, rs2, rs1, 0, rd, 0x3b); +} + +static inline u32 rv_divuw(u8 rd, u8 rs1, u8 rs2) +{ + return rv_r_insn(1, rs2, rs1, 5, rd, 0x3b); +} + +static inline u32 rv_remuw(u8 rd, u8 rs1, u8 rs2) +{ + return rv_r_insn(1, rs2, rs1, 7, rd, 0x3b); +} + +static inline u32 rv_ld(u8 rd, u16 imm11_0, u8 rs1) +{ + return rv_i_insn(imm11_0, rs1, 3, rd, 0x03); +} + +static inline u32 rv_lwu(u8 rd, u16 imm11_0, u8 rs1) +{ + return rv_i_insn(imm11_0, rs1, 6, rd, 0x03); +} + +static inline u32 rv_sd(u8 rs1, u16 imm11_0, u8 rs2) +{ + return rv_s_insn(imm11_0, rs2, rs1, 3, 0x23); +} + +static inline u32 rv_amoadd_d(u8 rd, u8 rs2, u8 rs1, u8 aq, u8 rl) +{ + return rv_amo_insn(0, aq, rl, rs2, rs1, 3, rd, 0x2f); +} + +static inline u32 rv_amoand_d(u8 rd, u8 rs2, u8 rs1, u8 aq, u8 rl) +{ + return rv_amo_insn(0xc, aq, rl, rs2, rs1, 3, rd, 0x2f); +} + +static inline u32 rv_amoor_d(u8 rd, u8 rs2, u8 rs1, u8 aq, u8 rl) +{ + return rv_amo_insn(0x8, aq, rl, rs2, rs1, 3, rd, 0x2f); +} + +static inline u32 rv_amoxor_d(u8 rd, u8 rs2, u8 rs1, u8 aq, u8 rl) +{ + return rv_amo_insn(0x4, aq, rl, rs2, rs1, 3, rd, 0x2f); +} + +static inline u32 rv_amoswap_d(u8 rd, u8 rs2, u8 rs1, u8 aq, u8 rl) +{ + return rv_amo_insn(0x1, aq, rl, rs2, rs1, 3, rd, 0x2f); +} + +static inline u32 rv_lr_d(u8 rd, u8 rs2, u8 rs1, u8 aq, u8 rl) +{ + return rv_amo_insn(0x2, aq, rl, rs2, rs1, 3, rd, 0x2f); +} + +static inline u32 rv_sc_d(u8 rd, u8 rs2, u8 rs1, u8 aq, u8 rl) +{ + return rv_amo_insn(0x3, aq, rl, rs2, rs1, 3, rd, 0x2f); +} + +/* RV64-only RVC instructions. */ + +static inline u16 rvc_ld(u8 rd, u32 imm8, u8 rs1) +{ + u32 imm_hi, imm_lo; + + imm_hi = (imm8 & 0x38) >> 3; + imm_lo = (imm8 & 0xc0) >> 6; + return rv_cl_insn(0x3, imm_hi, rs1, imm_lo, rd, 0x0); +} + +static inline u16 rvc_sd(u8 rs1, u32 imm8, u8 rs2) +{ + u32 imm_hi, imm_lo; + + imm_hi = (imm8 & 0x38) >> 3; + imm_lo = (imm8 & 0xc0) >> 6; + return rv_cs_insn(0x7, imm_hi, rs1, imm_lo, rs2, 0x0); +} + +static inline u16 rvc_subw(u8 rd, u8 rs) +{ + return rv_ca_insn(0x27, rd, 0, rs, 0x1); +} + +static inline u16 rvc_addiw(u8 rd, u32 imm6) +{ + return rv_ci_insn(0x1, imm6, rd, 0x1); +} + +static inline u16 rvc_ldsp(u8 rd, u32 imm9) +{ + u32 imm; + + imm = ((imm9 & 0x1c0) >> 6) | (imm9 & 0x38); + return rv_ci_insn(0x3, imm, rd, 0x2); +} + +static inline u16 rvc_sdsp(u32 imm9, u8 rs2) +{ + u32 imm; + + imm = (imm9 & 0x38) | ((imm9 & 0x1c0) >> 6); + return rv_css_insn(0x7, imm, rs2, 0x2); +} + +#endif /* __riscv_xlen == 64 */ + +/* Helper functions that emit RVC instructions when possible. */ + +static inline void emit_jalr(u8 rd, u8 rs, s32 imm, struct rv_jit_context *ctx) +{ + if (rvc_enabled() && rd == RV_REG_RA && rs && !imm) + emitc(rvc_jalr(rs), ctx); + else if (rvc_enabled() && !rd && rs && !imm) + emitc(rvc_jr(rs), ctx); + else + emit(rv_jalr(rd, rs, imm), ctx); +} + +static inline void emit_mv(u8 rd, u8 rs, struct rv_jit_context *ctx) +{ + if (rvc_enabled() && rd && rs) + emitc(rvc_mv(rd, rs), ctx); + else + emit(rv_addi(rd, rs, 0), ctx); +} + +static inline void emit_add(u8 rd, u8 rs1, u8 rs2, struct rv_jit_context *ctx) +{ + if (rvc_enabled() && rd && rd == rs1 && rs2) + emitc(rvc_add(rd, rs2), ctx); + else + emit(rv_add(rd, rs1, rs2), ctx); +} + +static inline void emit_addi(u8 rd, u8 rs, s32 imm, struct rv_jit_context *ctx) +{ + if (rvc_enabled() && rd == RV_REG_SP && rd == rs && is_10b_int(imm) && imm && !(imm & 0xf)) + emitc(rvc_addi16sp(imm), ctx); + else if (rvc_enabled() && is_creg(rd) && rs == RV_REG_SP && is_10b_uint(imm) && + !(imm & 0x3) && imm) + emitc(rvc_addi4spn(rd, imm), ctx); + else if (rvc_enabled() && rd && rd == rs && imm && is_6b_int(imm)) + emitc(rvc_addi(rd, imm), ctx); + else + emit(rv_addi(rd, rs, imm), ctx); +} + +static inline void emit_li(u8 rd, s32 imm, struct rv_jit_context *ctx) +{ + if (rvc_enabled() && rd && is_6b_int(imm)) + emitc(rvc_li(rd, imm), ctx); + else + emit(rv_addi(rd, RV_REG_ZERO, imm), ctx); +} + +static inline void emit_lui(u8 rd, s32 imm, struct rv_jit_context *ctx) +{ + if (rvc_enabled() && rd && rd != RV_REG_SP && is_6b_int(imm) && imm) + emitc(rvc_lui(rd, imm), ctx); + else + emit(rv_lui(rd, imm), ctx); +} + +static inline void emit_slli(u8 rd, u8 rs, s32 imm, struct rv_jit_context *ctx) +{ + if (rvc_enabled() && rd && rd == rs && imm && (u32)imm < __riscv_xlen) + emitc(rvc_slli(rd, imm), ctx); + else + emit(rv_slli(rd, rs, imm), ctx); +} + +static inline void emit_andi(u8 rd, u8 rs, s32 imm, struct rv_jit_context *ctx) +{ + if (rvc_enabled() && is_creg(rd) && rd == rs && is_6b_int(imm)) + emitc(rvc_andi(rd, imm), ctx); + else + emit(rv_andi(rd, rs, imm), ctx); +} + +static inline void emit_srli(u8 rd, u8 rs, s32 imm, struct rv_jit_context *ctx) +{ + if (rvc_enabled() && is_creg(rd) && rd == rs && imm && (u32)imm < __riscv_xlen) + emitc(rvc_srli(rd, imm), ctx); + else + emit(rv_srli(rd, rs, imm), ctx); +} + +static inline void emit_srai(u8 rd, u8 rs, s32 imm, struct rv_jit_context *ctx) +{ + if (rvc_enabled() && is_creg(rd) && rd == rs && imm && (u32)imm < __riscv_xlen) + emitc(rvc_srai(rd, imm), ctx); + else + emit(rv_srai(rd, rs, imm), ctx); +} + +static inline void emit_sub(u8 rd, u8 rs1, u8 rs2, struct rv_jit_context *ctx) +{ + if (rvc_enabled() && is_creg(rd) && rd == rs1 && is_creg(rs2)) + emitc(rvc_sub(rd, rs2), ctx); + else + emit(rv_sub(rd, rs1, rs2), ctx); +} + +static inline void emit_or(u8 rd, u8 rs1, u8 rs2, struct rv_jit_context *ctx) +{ + if (rvc_enabled() && is_creg(rd) && rd == rs1 && is_creg(rs2)) + emitc(rvc_or(rd, rs2), ctx); + else + emit(rv_or(rd, rs1, rs2), ctx); +} + +static inline void emit_and(u8 rd, u8 rs1, u8 rs2, struct rv_jit_context *ctx) +{ + if (rvc_enabled() && is_creg(rd) && rd == rs1 && is_creg(rs2)) + emitc(rvc_and(rd, rs2), ctx); + else + emit(rv_and(rd, rs1, rs2), ctx); +} + +static inline void emit_xor(u8 rd, u8 rs1, u8 rs2, struct rv_jit_context *ctx) +{ + if (rvc_enabled() && is_creg(rd) && rd == rs1 && is_creg(rs2)) + emitc(rvc_xor(rd, rs2), ctx); + else + emit(rv_xor(rd, rs1, rs2), ctx); +} + +static inline void emit_lw(u8 rd, s32 off, u8 rs1, struct rv_jit_context *ctx) +{ + if (rvc_enabled() && rs1 == RV_REG_SP && rd && is_8b_uint(off) && !(off & 0x3)) + emitc(rvc_lwsp(rd, off), ctx); + else if (rvc_enabled() && is_creg(rd) && is_creg(rs1) && is_7b_uint(off) && !(off & 0x3)) + emitc(rvc_lw(rd, off, rs1), ctx); + else + emit(rv_lw(rd, off, rs1), ctx); +} + +static inline void emit_sw(u8 rs1, s32 off, u8 rs2, struct rv_jit_context *ctx) +{ + if (rvc_enabled() && rs1 == RV_REG_SP && is_8b_uint(off) && !(off & 0x3)) + emitc(rvc_swsp(off, rs2), ctx); + else if (rvc_enabled() && is_creg(rs1) && is_creg(rs2) && is_7b_uint(off) && !(off & 0x3)) + emitc(rvc_sw(rs1, off, rs2), ctx); + else + emit(rv_sw(rs1, off, rs2), ctx); +} + +/* RV64-only helper functions. */ +#if __riscv_xlen == 64 + +static inline void emit_addiw(u8 rd, u8 rs, s32 imm, struct rv_jit_context *ctx) +{ + if (rvc_enabled() && rd && rd == rs && is_6b_int(imm)) + emitc(rvc_addiw(rd, imm), ctx); + else + emit(rv_addiw(rd, rs, imm), ctx); +} + +static inline void emit_ld(u8 rd, s32 off, u8 rs1, struct rv_jit_context *ctx) +{ + if (rvc_enabled() && rs1 == RV_REG_SP && rd && is_9b_uint(off) && !(off & 0x7)) + emitc(rvc_ldsp(rd, off), ctx); + else if (rvc_enabled() && is_creg(rd) && is_creg(rs1) && is_8b_uint(off) && !(off & 0x7)) + emitc(rvc_ld(rd, off, rs1), ctx); + else + emit(rv_ld(rd, off, rs1), ctx); +} + +static inline void emit_sd(u8 rs1, s32 off, u8 rs2, struct rv_jit_context *ctx) +{ + if (rvc_enabled() && rs1 == RV_REG_SP && is_9b_uint(off) && !(off & 0x7)) + emitc(rvc_sdsp(off, rs2), ctx); + else if (rvc_enabled() && is_creg(rs1) && is_creg(rs2) && is_8b_uint(off) && !(off & 0x7)) + emitc(rvc_sd(rs1, off, rs2), ctx); + else + emit(rv_sd(rs1, off, rs2), ctx); +} + +static inline void emit_subw(u8 rd, u8 rs1, u8 rs2, struct rv_jit_context *ctx) +{ + if (rvc_enabled() && is_creg(rd) && rd == rs1 && is_creg(rs2)) + emitc(rvc_subw(rd, rs2), ctx); + else + emit(rv_subw(rd, rs1, rs2), ctx); +} + +#endif /* __riscv_xlen == 64 */ + +void bpf_jit_build_prologue(struct rv_jit_context *ctx); +void bpf_jit_build_epilogue(struct rv_jit_context *ctx); + +int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, + bool extra_pass); + +#endif /* _BPF_JIT_H */ diff --git a/arch/riscv/net/bpf_jit_comp32.c b/arch/riscv/net/bpf_jit_comp32.c new file mode 100644 index 000000000..529a83b85 --- /dev/null +++ b/arch/riscv/net/bpf_jit_comp32.c @@ -0,0 +1,1357 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * BPF JIT compiler for RV32G + * + * Copyright (c) 2020 Luke Nelson <luke.r.nels@gmail.com> + * Copyright (c) 2020 Xi Wang <xi.wang@gmail.com> + * + * The code is based on the BPF JIT compiler for RV64G by Björn Töpel and + * the BPF JIT compiler for 32-bit ARM by Shubham Bansal and Mircea Gherzan. + */ + +#include <linux/bpf.h> +#include <linux/filter.h> +#include "bpf_jit.h" + +/* + * Stack layout during BPF program execution: + * + * high + * RV32 fp => +----------+ + * | saved ra | + * | saved fp | RV32 callee-saved registers + * | ... | + * +----------+ <= (fp - 4 * NR_SAVED_REGISTERS) + * | hi(R6) | + * | lo(R6) | + * | hi(R7) | JIT scratch space for BPF registers + * | lo(R7) | + * | ... | + * BPF_REG_FP => +----------+ <= (fp - 4 * NR_SAVED_REGISTERS + * | | - 4 * BPF_JIT_SCRATCH_REGS) + * | | + * | ... | BPF program stack + * | | + * RV32 sp => +----------+ + * | | + * | ... | Function call stack + * | | + * +----------+ + * low + */ + +enum { + /* Stack layout - these are offsets from top of JIT scratch space. */ + BPF_R6_HI, + BPF_R6_LO, + BPF_R7_HI, + BPF_R7_LO, + BPF_R8_HI, + BPF_R8_LO, + BPF_R9_HI, + BPF_R9_LO, + BPF_AX_HI, + BPF_AX_LO, + /* Stack space for BPF_REG_6 through BPF_REG_9 and BPF_REG_AX. */ + BPF_JIT_SCRATCH_REGS, +}; + +/* Number of callee-saved registers stored to stack: ra, fp, s1--s7. */ +#define NR_SAVED_REGISTERS 9 + +/* Offset from fp for BPF registers stored on stack. */ +#define STACK_OFFSET(k) (-4 - (4 * NR_SAVED_REGISTERS) - (4 * (k))) + +#define TMP_REG_1 (MAX_BPF_JIT_REG + 0) +#define TMP_REG_2 (MAX_BPF_JIT_REG + 1) + +#define RV_REG_TCC RV_REG_T6 +#define RV_REG_TCC_SAVED RV_REG_S7 + +static const s8 bpf2rv32[][2] = { + /* Return value from in-kernel function, and exit value from eBPF. */ + [BPF_REG_0] = {RV_REG_S2, RV_REG_S1}, + /* Arguments from eBPF program to in-kernel function. */ + [BPF_REG_1] = {RV_REG_A1, RV_REG_A0}, + [BPF_REG_2] = {RV_REG_A3, RV_REG_A2}, + [BPF_REG_3] = {RV_REG_A5, RV_REG_A4}, + [BPF_REG_4] = {RV_REG_A7, RV_REG_A6}, + [BPF_REG_5] = {RV_REG_S4, RV_REG_S3}, + /* + * Callee-saved registers that in-kernel function will preserve. + * Stored on the stack. + */ + [BPF_REG_6] = {STACK_OFFSET(BPF_R6_HI), STACK_OFFSET(BPF_R6_LO)}, + [BPF_REG_7] = {STACK_OFFSET(BPF_R7_HI), STACK_OFFSET(BPF_R7_LO)}, + [BPF_REG_8] = {STACK_OFFSET(BPF_R8_HI), STACK_OFFSET(BPF_R8_LO)}, + [BPF_REG_9] = {STACK_OFFSET(BPF_R9_HI), STACK_OFFSET(BPF_R9_LO)}, + /* Read-only frame pointer to access BPF stack. */ + [BPF_REG_FP] = {RV_REG_S6, RV_REG_S5}, + /* Temporary register for blinding constants. Stored on the stack. */ + [BPF_REG_AX] = {STACK_OFFSET(BPF_AX_HI), STACK_OFFSET(BPF_AX_LO)}, + /* + * Temporary registers used by the JIT to operate on registers stored + * on the stack. Save t0 and t1 to be used as temporaries in generated + * code. + */ + [TMP_REG_1] = {RV_REG_T3, RV_REG_T2}, + [TMP_REG_2] = {RV_REG_T5, RV_REG_T4}, +}; + +static s8 hi(const s8 *r) +{ + return r[0]; +} + +static s8 lo(const s8 *r) +{ + return r[1]; +} + +static void emit_imm(const s8 rd, s32 imm, struct rv_jit_context *ctx) +{ + u32 upper = (imm + (1 << 11)) >> 12; + u32 lower = imm & 0xfff; + + if (upper) { + emit(rv_lui(rd, upper), ctx); + emit(rv_addi(rd, rd, lower), ctx); + } else { + emit(rv_addi(rd, RV_REG_ZERO, lower), ctx); + } +} + +static void emit_imm32(const s8 *rd, s32 imm, struct rv_jit_context *ctx) +{ + /* Emit immediate into lower bits. */ + emit_imm(lo(rd), imm, ctx); + + /* Sign-extend into upper bits. */ + if (imm >= 0) + emit(rv_addi(hi(rd), RV_REG_ZERO, 0), ctx); + else + emit(rv_addi(hi(rd), RV_REG_ZERO, -1), ctx); +} + +static void emit_imm64(const s8 *rd, s32 imm_hi, s32 imm_lo, + struct rv_jit_context *ctx) +{ + emit_imm(lo(rd), imm_lo, ctx); + emit_imm(hi(rd), imm_hi, ctx); +} + +static void __build_epilogue(bool is_tail_call, struct rv_jit_context *ctx) +{ + int stack_adjust = ctx->stack_size; + const s8 *r0 = bpf2rv32[BPF_REG_0]; + + /* Set return value if not tail call. */ + if (!is_tail_call) { + emit(rv_addi(RV_REG_A0, lo(r0), 0), ctx); + emit(rv_addi(RV_REG_A1, hi(r0), 0), ctx); + } + + /* Restore callee-saved registers. */ + emit(rv_lw(RV_REG_RA, stack_adjust - 4, RV_REG_SP), ctx); + emit(rv_lw(RV_REG_FP, stack_adjust - 8, RV_REG_SP), ctx); + emit(rv_lw(RV_REG_S1, stack_adjust - 12, RV_REG_SP), ctx); + emit(rv_lw(RV_REG_S2, stack_adjust - 16, RV_REG_SP), ctx); + emit(rv_lw(RV_REG_S3, stack_adjust - 20, RV_REG_SP), ctx); + emit(rv_lw(RV_REG_S4, stack_adjust - 24, RV_REG_SP), ctx); + emit(rv_lw(RV_REG_S5, stack_adjust - 28, RV_REG_SP), ctx); + emit(rv_lw(RV_REG_S6, stack_adjust - 32, RV_REG_SP), ctx); + emit(rv_lw(RV_REG_S7, stack_adjust - 36, RV_REG_SP), ctx); + + emit(rv_addi(RV_REG_SP, RV_REG_SP, stack_adjust), ctx); + + if (is_tail_call) { + /* + * goto *(t0 + 4); + * Skips first instruction of prologue which initializes tail + * call counter. Assumes t0 contains address of target program, + * see emit_bpf_tail_call. + */ + emit(rv_jalr(RV_REG_ZERO, RV_REG_T0, 4), ctx); + } else { + emit(rv_jalr(RV_REG_ZERO, RV_REG_RA, 0), ctx); + } +} + +static bool is_stacked(s8 reg) +{ + return reg < 0; +} + +static const s8 *bpf_get_reg64(const s8 *reg, const s8 *tmp, + struct rv_jit_context *ctx) +{ + if (is_stacked(hi(reg))) { + emit(rv_lw(hi(tmp), hi(reg), RV_REG_FP), ctx); + emit(rv_lw(lo(tmp), lo(reg), RV_REG_FP), ctx); + reg = tmp; + } + return reg; +} + +static void bpf_put_reg64(const s8 *reg, const s8 *src, + struct rv_jit_context *ctx) +{ + if (is_stacked(hi(reg))) { + emit(rv_sw(RV_REG_FP, hi(reg), hi(src)), ctx); + emit(rv_sw(RV_REG_FP, lo(reg), lo(src)), ctx); + } +} + +static const s8 *bpf_get_reg32(const s8 *reg, const s8 *tmp, + struct rv_jit_context *ctx) +{ + if (is_stacked(lo(reg))) { + emit(rv_lw(lo(tmp), lo(reg), RV_REG_FP), ctx); + reg = tmp; + } + return reg; +} + +static void bpf_put_reg32(const s8 *reg, const s8 *src, + struct rv_jit_context *ctx) +{ + if (is_stacked(lo(reg))) { + emit(rv_sw(RV_REG_FP, lo(reg), lo(src)), ctx); + if (!ctx->prog->aux->verifier_zext) + emit(rv_sw(RV_REG_FP, hi(reg), RV_REG_ZERO), ctx); + } else if (!ctx->prog->aux->verifier_zext) { + emit(rv_addi(hi(reg), RV_REG_ZERO, 0), ctx); + } +} + +static void emit_jump_and_link(u8 rd, s32 rvoff, bool force_jalr, + struct rv_jit_context *ctx) +{ + s32 upper, lower; + + if (rvoff && is_21b_int(rvoff) && !force_jalr) { + emit(rv_jal(rd, rvoff >> 1), ctx); + return; + } + + upper = (rvoff + (1 << 11)) >> 12; + lower = rvoff & 0xfff; + emit(rv_auipc(RV_REG_T1, upper), ctx); + emit(rv_jalr(rd, RV_REG_T1, lower), ctx); +} + +static void emit_alu_i64(const s8 *dst, s32 imm, + struct rv_jit_context *ctx, const u8 op) +{ + const s8 *tmp1 = bpf2rv32[TMP_REG_1]; + const s8 *rd = bpf_get_reg64(dst, tmp1, ctx); + + switch (op) { + case BPF_MOV: + emit_imm32(rd, imm, ctx); + break; + case BPF_AND: + if (is_12b_int(imm)) { + emit(rv_andi(lo(rd), lo(rd), imm), ctx); + } else { + emit_imm(RV_REG_T0, imm, ctx); + emit(rv_and(lo(rd), lo(rd), RV_REG_T0), ctx); + } + if (imm >= 0) + emit(rv_addi(hi(rd), RV_REG_ZERO, 0), ctx); + break; + case BPF_OR: + if (is_12b_int(imm)) { + emit(rv_ori(lo(rd), lo(rd), imm), ctx); + } else { + emit_imm(RV_REG_T0, imm, ctx); + emit(rv_or(lo(rd), lo(rd), RV_REG_T0), ctx); + } + if (imm < 0) + emit(rv_ori(hi(rd), RV_REG_ZERO, -1), ctx); + break; + case BPF_XOR: + if (is_12b_int(imm)) { + emit(rv_xori(lo(rd), lo(rd), imm), ctx); + } else { + emit_imm(RV_REG_T0, imm, ctx); + emit(rv_xor(lo(rd), lo(rd), RV_REG_T0), ctx); + } + if (imm < 0) + emit(rv_xori(hi(rd), hi(rd), -1), ctx); + break; + case BPF_LSH: + if (imm >= 32) { + emit(rv_slli(hi(rd), lo(rd), imm - 32), ctx); + emit(rv_addi(lo(rd), RV_REG_ZERO, 0), ctx); + } else if (imm == 0) { + /* Do nothing. */ + } else { + emit(rv_srli(RV_REG_T0, lo(rd), 32 - imm), ctx); + emit(rv_slli(hi(rd), hi(rd), imm), ctx); + emit(rv_or(hi(rd), RV_REG_T0, hi(rd)), ctx); + emit(rv_slli(lo(rd), lo(rd), imm), ctx); + } + break; + case BPF_RSH: + if (imm >= 32) { + emit(rv_srli(lo(rd), hi(rd), imm - 32), ctx); + emit(rv_addi(hi(rd), RV_REG_ZERO, 0), ctx); + } else if (imm == 0) { + /* Do nothing. */ + } else { + emit(rv_slli(RV_REG_T0, hi(rd), 32 - imm), ctx); + emit(rv_srli(lo(rd), lo(rd), imm), ctx); + emit(rv_or(lo(rd), RV_REG_T0, lo(rd)), ctx); + emit(rv_srli(hi(rd), hi(rd), imm), ctx); + } + break; + case BPF_ARSH: + if (imm >= 32) { + emit(rv_srai(lo(rd), hi(rd), imm - 32), ctx); + emit(rv_srai(hi(rd), hi(rd), 31), ctx); + } else if (imm == 0) { + /* Do nothing. */ + } else { + emit(rv_slli(RV_REG_T0, hi(rd), 32 - imm), ctx); + emit(rv_srli(lo(rd), lo(rd), imm), ctx); + emit(rv_or(lo(rd), RV_REG_T0, lo(rd)), ctx); + emit(rv_srai(hi(rd), hi(rd), imm), ctx); + } + break; + } + + bpf_put_reg64(dst, rd, ctx); +} + +static void emit_alu_i32(const s8 *dst, s32 imm, + struct rv_jit_context *ctx, const u8 op) +{ + const s8 *tmp1 = bpf2rv32[TMP_REG_1]; + const s8 *rd = bpf_get_reg32(dst, tmp1, ctx); + + switch (op) { + case BPF_MOV: + emit_imm(lo(rd), imm, ctx); + break; + case BPF_ADD: + if (is_12b_int(imm)) { + emit(rv_addi(lo(rd), lo(rd), imm), ctx); + } else { + emit_imm(RV_REG_T0, imm, ctx); + emit(rv_add(lo(rd), lo(rd), RV_REG_T0), ctx); + } + break; + case BPF_SUB: + if (is_12b_int(-imm)) { + emit(rv_addi(lo(rd), lo(rd), -imm), ctx); + } else { + emit_imm(RV_REG_T0, imm, ctx); + emit(rv_sub(lo(rd), lo(rd), RV_REG_T0), ctx); + } + break; + case BPF_AND: + if (is_12b_int(imm)) { + emit(rv_andi(lo(rd), lo(rd), imm), ctx); + } else { + emit_imm(RV_REG_T0, imm, ctx); + emit(rv_and(lo(rd), lo(rd), RV_REG_T0), ctx); + } + break; + case BPF_OR: + if (is_12b_int(imm)) { + emit(rv_ori(lo(rd), lo(rd), imm), ctx); + } else { + emit_imm(RV_REG_T0, imm, ctx); + emit(rv_or(lo(rd), lo(rd), RV_REG_T0), ctx); + } + break; + case BPF_XOR: + if (is_12b_int(imm)) { + emit(rv_xori(lo(rd), lo(rd), imm), ctx); + } else { + emit_imm(RV_REG_T0, imm, ctx); + emit(rv_xor(lo(rd), lo(rd), RV_REG_T0), ctx); + } + break; + case BPF_LSH: + if (is_12b_int(imm)) { + emit(rv_slli(lo(rd), lo(rd), imm), ctx); + } else { + emit_imm(RV_REG_T0, imm, ctx); + emit(rv_sll(lo(rd), lo(rd), RV_REG_T0), ctx); + } + break; + case BPF_RSH: + if (is_12b_int(imm)) { + emit(rv_srli(lo(rd), lo(rd), imm), ctx); + } else { + emit_imm(RV_REG_T0, imm, ctx); + emit(rv_srl(lo(rd), lo(rd), RV_REG_T0), ctx); + } + break; + case BPF_ARSH: + if (is_12b_int(imm)) { + emit(rv_srai(lo(rd), lo(rd), imm), ctx); + } else { + emit_imm(RV_REG_T0, imm, ctx); + emit(rv_sra(lo(rd), lo(rd), RV_REG_T0), ctx); + } + break; + } + + bpf_put_reg32(dst, rd, ctx); +} + +static void emit_alu_r64(const s8 *dst, const s8 *src, + struct rv_jit_context *ctx, const u8 op) +{ + const s8 *tmp1 = bpf2rv32[TMP_REG_1]; + const s8 *tmp2 = bpf2rv32[TMP_REG_2]; + const s8 *rd = bpf_get_reg64(dst, tmp1, ctx); + const s8 *rs = bpf_get_reg64(src, tmp2, ctx); + + switch (op) { + case BPF_MOV: + emit(rv_addi(lo(rd), lo(rs), 0), ctx); + emit(rv_addi(hi(rd), hi(rs), 0), ctx); + break; + case BPF_ADD: + if (rd == rs) { + emit(rv_srli(RV_REG_T0, lo(rd), 31), ctx); + emit(rv_slli(hi(rd), hi(rd), 1), ctx); + emit(rv_or(hi(rd), RV_REG_T0, hi(rd)), ctx); + emit(rv_slli(lo(rd), lo(rd), 1), ctx); + } else { + emit(rv_add(lo(rd), lo(rd), lo(rs)), ctx); + emit(rv_sltu(RV_REG_T0, lo(rd), lo(rs)), ctx); + emit(rv_add(hi(rd), hi(rd), hi(rs)), ctx); + emit(rv_add(hi(rd), hi(rd), RV_REG_T0), ctx); + } + break; + case BPF_SUB: + emit(rv_sub(RV_REG_T1, hi(rd), hi(rs)), ctx); + emit(rv_sltu(RV_REG_T0, lo(rd), lo(rs)), ctx); + emit(rv_sub(hi(rd), RV_REG_T1, RV_REG_T0), ctx); + emit(rv_sub(lo(rd), lo(rd), lo(rs)), ctx); + break; + case BPF_AND: + emit(rv_and(lo(rd), lo(rd), lo(rs)), ctx); + emit(rv_and(hi(rd), hi(rd), hi(rs)), ctx); + break; + case BPF_OR: + emit(rv_or(lo(rd), lo(rd), lo(rs)), ctx); + emit(rv_or(hi(rd), hi(rd), hi(rs)), ctx); + break; + case BPF_XOR: + emit(rv_xor(lo(rd), lo(rd), lo(rs)), ctx); + emit(rv_xor(hi(rd), hi(rd), hi(rs)), ctx); + break; + case BPF_MUL: + emit(rv_mul(RV_REG_T0, hi(rs), lo(rd)), ctx); + emit(rv_mul(hi(rd), hi(rd), lo(rs)), ctx); + emit(rv_mulhu(RV_REG_T1, lo(rd), lo(rs)), ctx); + emit(rv_add(hi(rd), hi(rd), RV_REG_T0), ctx); + emit(rv_mul(lo(rd), lo(rd), lo(rs)), ctx); + emit(rv_add(hi(rd), hi(rd), RV_REG_T1), ctx); + break; + case BPF_LSH: + emit(rv_addi(RV_REG_T0, lo(rs), -32), ctx); + emit(rv_blt(RV_REG_T0, RV_REG_ZERO, 8), ctx); + emit(rv_sll(hi(rd), lo(rd), RV_REG_T0), ctx); + emit(rv_addi(lo(rd), RV_REG_ZERO, 0), ctx); + emit(rv_jal(RV_REG_ZERO, 16), ctx); + emit(rv_addi(RV_REG_T1, RV_REG_ZERO, 31), ctx); + emit(rv_srli(RV_REG_T0, lo(rd), 1), ctx); + emit(rv_sub(RV_REG_T1, RV_REG_T1, lo(rs)), ctx); + emit(rv_srl(RV_REG_T0, RV_REG_T0, RV_REG_T1), ctx); + emit(rv_sll(hi(rd), hi(rd), lo(rs)), ctx); + emit(rv_or(hi(rd), RV_REG_T0, hi(rd)), ctx); + emit(rv_sll(lo(rd), lo(rd), lo(rs)), ctx); + break; + case BPF_RSH: + emit(rv_addi(RV_REG_T0, lo(rs), -32), ctx); + emit(rv_blt(RV_REG_T0, RV_REG_ZERO, 8), ctx); + emit(rv_srl(lo(rd), hi(rd), RV_REG_T0), ctx); + emit(rv_addi(hi(rd), RV_REG_ZERO, 0), ctx); + emit(rv_jal(RV_REG_ZERO, 16), ctx); + emit(rv_addi(RV_REG_T1, RV_REG_ZERO, 31), ctx); + emit(rv_slli(RV_REG_T0, hi(rd), 1), ctx); + emit(rv_sub(RV_REG_T1, RV_REG_T1, lo(rs)), ctx); + emit(rv_sll(RV_REG_T0, RV_REG_T0, RV_REG_T1), ctx); + emit(rv_srl(lo(rd), lo(rd), lo(rs)), ctx); + emit(rv_or(lo(rd), RV_REG_T0, lo(rd)), ctx); + emit(rv_srl(hi(rd), hi(rd), lo(rs)), ctx); + break; + case BPF_ARSH: + emit(rv_addi(RV_REG_T0, lo(rs), -32), ctx); + emit(rv_blt(RV_REG_T0, RV_REG_ZERO, 8), ctx); + emit(rv_sra(lo(rd), hi(rd), RV_REG_T0), ctx); + emit(rv_srai(hi(rd), hi(rd), 31), ctx); + emit(rv_jal(RV_REG_ZERO, 16), ctx); + emit(rv_addi(RV_REG_T1, RV_REG_ZERO, 31), ctx); + emit(rv_slli(RV_REG_T0, hi(rd), 1), ctx); + emit(rv_sub(RV_REG_T1, RV_REG_T1, lo(rs)), ctx); + emit(rv_sll(RV_REG_T0, RV_REG_T0, RV_REG_T1), ctx); + emit(rv_srl(lo(rd), lo(rd), lo(rs)), ctx); + emit(rv_or(lo(rd), RV_REG_T0, lo(rd)), ctx); + emit(rv_sra(hi(rd), hi(rd), lo(rs)), ctx); + break; + case BPF_NEG: + emit(rv_sub(lo(rd), RV_REG_ZERO, lo(rd)), ctx); + emit(rv_sltu(RV_REG_T0, RV_REG_ZERO, lo(rd)), ctx); + emit(rv_sub(hi(rd), RV_REG_ZERO, hi(rd)), ctx); + emit(rv_sub(hi(rd), hi(rd), RV_REG_T0), ctx); + break; + } + + bpf_put_reg64(dst, rd, ctx); +} + +static void emit_alu_r32(const s8 *dst, const s8 *src, + struct rv_jit_context *ctx, const u8 op) +{ + const s8 *tmp1 = bpf2rv32[TMP_REG_1]; + const s8 *tmp2 = bpf2rv32[TMP_REG_2]; + const s8 *rd = bpf_get_reg32(dst, tmp1, ctx); + const s8 *rs = bpf_get_reg32(src, tmp2, ctx); + + switch (op) { + case BPF_MOV: + emit(rv_addi(lo(rd), lo(rs), 0), ctx); + break; + case BPF_ADD: + emit(rv_add(lo(rd), lo(rd), lo(rs)), ctx); + break; + case BPF_SUB: + emit(rv_sub(lo(rd), lo(rd), lo(rs)), ctx); + break; + case BPF_AND: + emit(rv_and(lo(rd), lo(rd), lo(rs)), ctx); + break; + case BPF_OR: + emit(rv_or(lo(rd), lo(rd), lo(rs)), ctx); + break; + case BPF_XOR: + emit(rv_xor(lo(rd), lo(rd), lo(rs)), ctx); + break; + case BPF_MUL: + emit(rv_mul(lo(rd), lo(rd), lo(rs)), ctx); + break; + case BPF_DIV: + emit(rv_divu(lo(rd), lo(rd), lo(rs)), ctx); + break; + case BPF_MOD: + emit(rv_remu(lo(rd), lo(rd), lo(rs)), ctx); + break; + case BPF_LSH: + emit(rv_sll(lo(rd), lo(rd), lo(rs)), ctx); + break; + case BPF_RSH: + emit(rv_srl(lo(rd), lo(rd), lo(rs)), ctx); + break; + case BPF_ARSH: + emit(rv_sra(lo(rd), lo(rd), lo(rs)), ctx); + break; + case BPF_NEG: + emit(rv_sub(lo(rd), RV_REG_ZERO, lo(rd)), ctx); + break; + } + + bpf_put_reg32(dst, rd, ctx); +} + +static int emit_branch_r64(const s8 *src1, const s8 *src2, s32 rvoff, + struct rv_jit_context *ctx, const u8 op) +{ + int e, s = ctx->ninsns; + const s8 *tmp1 = bpf2rv32[TMP_REG_1]; + const s8 *tmp2 = bpf2rv32[TMP_REG_2]; + + const s8 *rs1 = bpf_get_reg64(src1, tmp1, ctx); + const s8 *rs2 = bpf_get_reg64(src2, tmp2, ctx); + + /* + * NO_JUMP skips over the rest of the instructions and the + * emit_jump_and_link, meaning the BPF branch is not taken. + * JUMP skips directly to the emit_jump_and_link, meaning + * the BPF branch is taken. + * + * The fallthrough case results in the BPF branch being taken. + */ +#define NO_JUMP(idx) (6 + (2 * (idx))) +#define JUMP(idx) (2 + (2 * (idx))) + + switch (op) { + case BPF_JEQ: + emit(rv_bne(hi(rs1), hi(rs2), NO_JUMP(1)), ctx); + emit(rv_bne(lo(rs1), lo(rs2), NO_JUMP(0)), ctx); + break; + case BPF_JGT: + emit(rv_bgtu(hi(rs1), hi(rs2), JUMP(2)), ctx); + emit(rv_bltu(hi(rs1), hi(rs2), NO_JUMP(1)), ctx); + emit(rv_bleu(lo(rs1), lo(rs2), NO_JUMP(0)), ctx); + break; + case BPF_JLT: + emit(rv_bltu(hi(rs1), hi(rs2), JUMP(2)), ctx); + emit(rv_bgtu(hi(rs1), hi(rs2), NO_JUMP(1)), ctx); + emit(rv_bgeu(lo(rs1), lo(rs2), NO_JUMP(0)), ctx); + break; + case BPF_JGE: + emit(rv_bgtu(hi(rs1), hi(rs2), JUMP(2)), ctx); + emit(rv_bltu(hi(rs1), hi(rs2), NO_JUMP(1)), ctx); + emit(rv_bltu(lo(rs1), lo(rs2), NO_JUMP(0)), ctx); + break; + case BPF_JLE: + emit(rv_bltu(hi(rs1), hi(rs2), JUMP(2)), ctx); + emit(rv_bgtu(hi(rs1), hi(rs2), NO_JUMP(1)), ctx); + emit(rv_bgtu(lo(rs1), lo(rs2), NO_JUMP(0)), ctx); + break; + case BPF_JNE: + emit(rv_bne(hi(rs1), hi(rs2), JUMP(1)), ctx); + emit(rv_beq(lo(rs1), lo(rs2), NO_JUMP(0)), ctx); + break; + case BPF_JSGT: + emit(rv_bgt(hi(rs1), hi(rs2), JUMP(2)), ctx); + emit(rv_blt(hi(rs1), hi(rs2), NO_JUMP(1)), ctx); + emit(rv_bleu(lo(rs1), lo(rs2), NO_JUMP(0)), ctx); + break; + case BPF_JSLT: + emit(rv_blt(hi(rs1), hi(rs2), JUMP(2)), ctx); + emit(rv_bgt(hi(rs1), hi(rs2), NO_JUMP(1)), ctx); + emit(rv_bgeu(lo(rs1), lo(rs2), NO_JUMP(0)), ctx); + break; + case BPF_JSGE: + emit(rv_bgt(hi(rs1), hi(rs2), JUMP(2)), ctx); + emit(rv_blt(hi(rs1), hi(rs2), NO_JUMP(1)), ctx); + emit(rv_bltu(lo(rs1), lo(rs2), NO_JUMP(0)), ctx); + break; + case BPF_JSLE: + emit(rv_blt(hi(rs1), hi(rs2), JUMP(2)), ctx); + emit(rv_bgt(hi(rs1), hi(rs2), NO_JUMP(1)), ctx); + emit(rv_bgtu(lo(rs1), lo(rs2), NO_JUMP(0)), ctx); + break; + case BPF_JSET: + emit(rv_and(RV_REG_T0, hi(rs1), hi(rs2)), ctx); + emit(rv_bne(RV_REG_T0, RV_REG_ZERO, JUMP(2)), ctx); + emit(rv_and(RV_REG_T0, lo(rs1), lo(rs2)), ctx); + emit(rv_beq(RV_REG_T0, RV_REG_ZERO, NO_JUMP(0)), ctx); + break; + } + +#undef NO_JUMP +#undef JUMP + + e = ctx->ninsns; + /* Adjust for extra insns. */ + rvoff -= ninsns_rvoff(e - s); + emit_jump_and_link(RV_REG_ZERO, rvoff, true, ctx); + return 0; +} + +static int emit_bcc(u8 op, u8 rd, u8 rs, int rvoff, struct rv_jit_context *ctx) +{ + int e, s = ctx->ninsns; + bool far = false; + int off; + + if (op == BPF_JSET) { + /* + * BPF_JSET is a special case: it has no inverse so we always + * treat it as a far branch. + */ + far = true; + } else if (!is_13b_int(rvoff)) { + op = invert_bpf_cond(op); + far = true; + } + + /* + * For a far branch, the condition is negated and we jump over the + * branch itself, and the two instructions from emit_jump_and_link. + * For a near branch, just use rvoff. + */ + off = far ? 6 : (rvoff >> 1); + + switch (op) { + case BPF_JEQ: + emit(rv_beq(rd, rs, off), ctx); + break; + case BPF_JGT: + emit(rv_bgtu(rd, rs, off), ctx); + break; + case BPF_JLT: + emit(rv_bltu(rd, rs, off), ctx); + break; + case BPF_JGE: + emit(rv_bgeu(rd, rs, off), ctx); + break; + case BPF_JLE: + emit(rv_bleu(rd, rs, off), ctx); + break; + case BPF_JNE: + emit(rv_bne(rd, rs, off), ctx); + break; + case BPF_JSGT: + emit(rv_bgt(rd, rs, off), ctx); + break; + case BPF_JSLT: + emit(rv_blt(rd, rs, off), ctx); + break; + case BPF_JSGE: + emit(rv_bge(rd, rs, off), ctx); + break; + case BPF_JSLE: + emit(rv_ble(rd, rs, off), ctx); + break; + case BPF_JSET: + emit(rv_and(RV_REG_T0, rd, rs), ctx); + emit(rv_beq(RV_REG_T0, RV_REG_ZERO, off), ctx); + break; + } + + if (far) { + e = ctx->ninsns; + /* Adjust for extra insns. */ + rvoff -= ninsns_rvoff(e - s); + emit_jump_and_link(RV_REG_ZERO, rvoff, true, ctx); + } + return 0; +} + +static int emit_branch_r32(const s8 *src1, const s8 *src2, s32 rvoff, + struct rv_jit_context *ctx, const u8 op) +{ + int e, s = ctx->ninsns; + const s8 *tmp1 = bpf2rv32[TMP_REG_1]; + const s8 *tmp2 = bpf2rv32[TMP_REG_2]; + + const s8 *rs1 = bpf_get_reg32(src1, tmp1, ctx); + const s8 *rs2 = bpf_get_reg32(src2, tmp2, ctx); + + e = ctx->ninsns; + /* Adjust for extra insns. */ + rvoff -= ninsns_rvoff(e - s); + + if (emit_bcc(op, lo(rs1), lo(rs2), rvoff, ctx)) + return -1; + + return 0; +} + +static void emit_call(bool fixed, u64 addr, struct rv_jit_context *ctx) +{ + const s8 *r0 = bpf2rv32[BPF_REG_0]; + const s8 *r5 = bpf2rv32[BPF_REG_5]; + u32 upper = ((u32)addr + (1 << 11)) >> 12; + u32 lower = addr & 0xfff; + + /* R1-R4 already in correct registers---need to push R5 to stack. */ + emit(rv_addi(RV_REG_SP, RV_REG_SP, -16), ctx); + emit(rv_sw(RV_REG_SP, 0, lo(r5)), ctx); + emit(rv_sw(RV_REG_SP, 4, hi(r5)), ctx); + + /* Backup TCC. */ + emit(rv_addi(RV_REG_TCC_SAVED, RV_REG_TCC, 0), ctx); + + /* + * Use lui/jalr pair to jump to absolute address. Don't use emit_imm as + * the number of emitted instructions should not depend on the value of + * addr. + */ + emit(rv_lui(RV_REG_T1, upper), ctx); + emit(rv_jalr(RV_REG_RA, RV_REG_T1, lower), ctx); + + /* Restore TCC. */ + emit(rv_addi(RV_REG_TCC, RV_REG_TCC_SAVED, 0), ctx); + + /* Set return value and restore stack. */ + emit(rv_addi(lo(r0), RV_REG_A0, 0), ctx); + emit(rv_addi(hi(r0), RV_REG_A1, 0), ctx); + emit(rv_addi(RV_REG_SP, RV_REG_SP, 16), ctx); +} + +static int emit_bpf_tail_call(int insn, struct rv_jit_context *ctx) +{ + /* + * R1 -> &ctx + * R2 -> &array + * R3 -> index + */ + int tc_ninsn, off, start_insn = ctx->ninsns; + const s8 *arr_reg = bpf2rv32[BPF_REG_2]; + const s8 *idx_reg = bpf2rv32[BPF_REG_3]; + + tc_ninsn = insn ? ctx->offset[insn] - ctx->offset[insn - 1] : + ctx->offset[0]; + + /* max_entries = array->map.max_entries; */ + off = offsetof(struct bpf_array, map.max_entries); + if (is_12b_check(off, insn)) + return -1; + emit(rv_lw(RV_REG_T1, off, lo(arr_reg)), ctx); + + /* + * if (index >= max_entries) + * goto out; + */ + off = ninsns_rvoff(tc_ninsn - (ctx->ninsns - start_insn)); + emit_bcc(BPF_JGE, lo(idx_reg), RV_REG_T1, off, ctx); + + /* + * if (--tcc < 0) + * goto out; + */ + emit(rv_addi(RV_REG_TCC, RV_REG_TCC, -1), ctx); + off = ninsns_rvoff(tc_ninsn - (ctx->ninsns - start_insn)); + emit_bcc(BPF_JSLT, RV_REG_TCC, RV_REG_ZERO, off, ctx); + + /* + * prog = array->ptrs[index]; + * if (!prog) + * goto out; + */ + emit(rv_slli(RV_REG_T0, lo(idx_reg), 2), ctx); + emit(rv_add(RV_REG_T0, RV_REG_T0, lo(arr_reg)), ctx); + off = offsetof(struct bpf_array, ptrs); + if (is_12b_check(off, insn)) + return -1; + emit(rv_lw(RV_REG_T0, off, RV_REG_T0), ctx); + off = ninsns_rvoff(tc_ninsn - (ctx->ninsns - start_insn)); + emit_bcc(BPF_JEQ, RV_REG_T0, RV_REG_ZERO, off, ctx); + + /* + * tcc = temp_tcc; + * goto *(prog->bpf_func + 4); + */ + off = offsetof(struct bpf_prog, bpf_func); + if (is_12b_check(off, insn)) + return -1; + emit(rv_lw(RV_REG_T0, off, RV_REG_T0), ctx); + /* Epilogue jumps to *(t0 + 4). */ + __build_epilogue(true, ctx); + return 0; +} + +static int emit_load_r64(const s8 *dst, const s8 *src, s16 off, + struct rv_jit_context *ctx, const u8 size) +{ + const s8 *tmp1 = bpf2rv32[TMP_REG_1]; + const s8 *tmp2 = bpf2rv32[TMP_REG_2]; + const s8 *rd = bpf_get_reg64(dst, tmp1, ctx); + const s8 *rs = bpf_get_reg64(src, tmp2, ctx); + + emit_imm(RV_REG_T0, off, ctx); + emit(rv_add(RV_REG_T0, RV_REG_T0, lo(rs)), ctx); + + switch (size) { + case BPF_B: + emit(rv_lbu(lo(rd), 0, RV_REG_T0), ctx); + if (!ctx->prog->aux->verifier_zext) + emit(rv_addi(hi(rd), RV_REG_ZERO, 0), ctx); + break; + case BPF_H: + emit(rv_lhu(lo(rd), 0, RV_REG_T0), ctx); + if (!ctx->prog->aux->verifier_zext) + emit(rv_addi(hi(rd), RV_REG_ZERO, 0), ctx); + break; + case BPF_W: + emit(rv_lw(lo(rd), 0, RV_REG_T0), ctx); + if (!ctx->prog->aux->verifier_zext) + emit(rv_addi(hi(rd), RV_REG_ZERO, 0), ctx); + break; + case BPF_DW: + emit(rv_lw(lo(rd), 0, RV_REG_T0), ctx); + emit(rv_lw(hi(rd), 4, RV_REG_T0), ctx); + break; + } + + bpf_put_reg64(dst, rd, ctx); + return 0; +} + +static int emit_store_r64(const s8 *dst, const s8 *src, s16 off, + struct rv_jit_context *ctx, const u8 size, + const u8 mode) +{ + const s8 *tmp1 = bpf2rv32[TMP_REG_1]; + const s8 *tmp2 = bpf2rv32[TMP_REG_2]; + const s8 *rd = bpf_get_reg64(dst, tmp1, ctx); + const s8 *rs = bpf_get_reg64(src, tmp2, ctx); + + if (mode == BPF_ATOMIC && size != BPF_W) + return -1; + + emit_imm(RV_REG_T0, off, ctx); + emit(rv_add(RV_REG_T0, RV_REG_T0, lo(rd)), ctx); + + switch (size) { + case BPF_B: + emit(rv_sb(RV_REG_T0, 0, lo(rs)), ctx); + break; + case BPF_H: + emit(rv_sh(RV_REG_T0, 0, lo(rs)), ctx); + break; + case BPF_W: + switch (mode) { + case BPF_MEM: + emit(rv_sw(RV_REG_T0, 0, lo(rs)), ctx); + break; + case BPF_ATOMIC: /* Only BPF_ADD supported */ + emit(rv_amoadd_w(RV_REG_ZERO, lo(rs), RV_REG_T0, 0, 0), + ctx); + break; + } + break; + case BPF_DW: + emit(rv_sw(RV_REG_T0, 0, lo(rs)), ctx); + emit(rv_sw(RV_REG_T0, 4, hi(rs)), ctx); + break; + } + + return 0; +} + +static void emit_rev16(const s8 rd, struct rv_jit_context *ctx) +{ + emit(rv_slli(rd, rd, 16), ctx); + emit(rv_slli(RV_REG_T1, rd, 8), ctx); + emit(rv_srli(rd, rd, 8), ctx); + emit(rv_add(RV_REG_T1, rd, RV_REG_T1), ctx); + emit(rv_srli(rd, RV_REG_T1, 16), ctx); +} + +static void emit_rev32(const s8 rd, struct rv_jit_context *ctx) +{ + emit(rv_addi(RV_REG_T1, RV_REG_ZERO, 0), ctx); + emit(rv_andi(RV_REG_T0, rd, 255), ctx); + emit(rv_add(RV_REG_T1, RV_REG_T1, RV_REG_T0), ctx); + emit(rv_slli(RV_REG_T1, RV_REG_T1, 8), ctx); + emit(rv_srli(rd, rd, 8), ctx); + emit(rv_andi(RV_REG_T0, rd, 255), ctx); + emit(rv_add(RV_REG_T1, RV_REG_T1, RV_REG_T0), ctx); + emit(rv_slli(RV_REG_T1, RV_REG_T1, 8), ctx); + emit(rv_srli(rd, rd, 8), ctx); + emit(rv_andi(RV_REG_T0, rd, 255), ctx); + emit(rv_add(RV_REG_T1, RV_REG_T1, RV_REG_T0), ctx); + emit(rv_slli(RV_REG_T1, RV_REG_T1, 8), ctx); + emit(rv_srli(rd, rd, 8), ctx); + emit(rv_andi(RV_REG_T0, rd, 255), ctx); + emit(rv_add(RV_REG_T1, RV_REG_T1, RV_REG_T0), ctx); + emit(rv_addi(rd, RV_REG_T1, 0), ctx); +} + +static void emit_zext64(const s8 *dst, struct rv_jit_context *ctx) +{ + const s8 *rd; + const s8 *tmp1 = bpf2rv32[TMP_REG_1]; + + rd = bpf_get_reg64(dst, tmp1, ctx); + emit(rv_addi(hi(rd), RV_REG_ZERO, 0), ctx); + bpf_put_reg64(dst, rd, ctx); +} + +int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, + bool extra_pass) +{ + bool is64 = BPF_CLASS(insn->code) == BPF_ALU64 || + BPF_CLASS(insn->code) == BPF_JMP; + int s, e, rvoff, i = insn - ctx->prog->insnsi; + u8 code = insn->code; + s16 off = insn->off; + s32 imm = insn->imm; + + const s8 *dst = bpf2rv32[insn->dst_reg]; + const s8 *src = bpf2rv32[insn->src_reg]; + const s8 *tmp1 = bpf2rv32[TMP_REG_1]; + const s8 *tmp2 = bpf2rv32[TMP_REG_2]; + + switch (code) { + case BPF_ALU64 | BPF_MOV | BPF_X: + + case BPF_ALU64 | BPF_ADD | BPF_X: + case BPF_ALU64 | BPF_ADD | BPF_K: + + case BPF_ALU64 | BPF_SUB | BPF_X: + case BPF_ALU64 | BPF_SUB | BPF_K: + + case BPF_ALU64 | BPF_AND | BPF_X: + case BPF_ALU64 | BPF_OR | BPF_X: + case BPF_ALU64 | BPF_XOR | BPF_X: + + case BPF_ALU64 | BPF_MUL | BPF_X: + case BPF_ALU64 | BPF_MUL | BPF_K: + + case BPF_ALU64 | BPF_LSH | BPF_X: + case BPF_ALU64 | BPF_RSH | BPF_X: + case BPF_ALU64 | BPF_ARSH | BPF_X: + if (BPF_SRC(code) == BPF_K) { + emit_imm32(tmp2, imm, ctx); + src = tmp2; + } + emit_alu_r64(dst, src, ctx, BPF_OP(code)); + break; + + case BPF_ALU64 | BPF_NEG: + emit_alu_r64(dst, tmp2, ctx, BPF_OP(code)); + break; + + case BPF_ALU64 | BPF_DIV | BPF_X: + case BPF_ALU64 | BPF_DIV | BPF_K: + case BPF_ALU64 | BPF_MOD | BPF_X: + case BPF_ALU64 | BPF_MOD | BPF_K: + goto notsupported; + + case BPF_ALU64 | BPF_MOV | BPF_K: + case BPF_ALU64 | BPF_AND | BPF_K: + case BPF_ALU64 | BPF_OR | BPF_K: + case BPF_ALU64 | BPF_XOR | BPF_K: + case BPF_ALU64 | BPF_LSH | BPF_K: + case BPF_ALU64 | BPF_RSH | BPF_K: + case BPF_ALU64 | BPF_ARSH | BPF_K: + emit_alu_i64(dst, imm, ctx, BPF_OP(code)); + break; + + case BPF_ALU | BPF_MOV | BPF_X: + if (imm == 1) { + /* Special mov32 for zext. */ + emit_zext64(dst, ctx); + break; + } + fallthrough; + + case BPF_ALU | BPF_ADD | BPF_X: + case BPF_ALU | BPF_SUB | BPF_X: + case BPF_ALU | BPF_AND | BPF_X: + case BPF_ALU | BPF_OR | BPF_X: + case BPF_ALU | BPF_XOR | BPF_X: + + case BPF_ALU | BPF_MUL | BPF_X: + case BPF_ALU | BPF_MUL | BPF_K: + + case BPF_ALU | BPF_DIV | BPF_X: + case BPF_ALU | BPF_DIV | BPF_K: + + case BPF_ALU | BPF_MOD | BPF_X: + case BPF_ALU | BPF_MOD | BPF_K: + + case BPF_ALU | BPF_LSH | BPF_X: + case BPF_ALU | BPF_RSH | BPF_X: + case BPF_ALU | BPF_ARSH | BPF_X: + if (BPF_SRC(code) == BPF_K) { + emit_imm32(tmp2, imm, ctx); + src = tmp2; + } + emit_alu_r32(dst, src, ctx, BPF_OP(code)); + break; + + case BPF_ALU | BPF_MOV | BPF_K: + case BPF_ALU | BPF_ADD | BPF_K: + case BPF_ALU | BPF_SUB | BPF_K: + case BPF_ALU | BPF_AND | BPF_K: + case BPF_ALU | BPF_OR | BPF_K: + case BPF_ALU | BPF_XOR | BPF_K: + case BPF_ALU | BPF_LSH | BPF_K: + case BPF_ALU | BPF_RSH | BPF_K: + case BPF_ALU | BPF_ARSH | BPF_K: + /* + * mul,div,mod are handled in the BPF_X case since there are + * no RISC-V I-type equivalents. + */ + emit_alu_i32(dst, imm, ctx, BPF_OP(code)); + break; + + case BPF_ALU | BPF_NEG: + /* + * src is ignored---choose tmp2 as a dummy register since it + * is not on the stack. + */ + emit_alu_r32(dst, tmp2, ctx, BPF_OP(code)); + break; + + case BPF_ALU | BPF_END | BPF_FROM_LE: + { + const s8 *rd = bpf_get_reg64(dst, tmp1, ctx); + + switch (imm) { + case 16: + emit(rv_slli(lo(rd), lo(rd), 16), ctx); + emit(rv_srli(lo(rd), lo(rd), 16), ctx); + fallthrough; + case 32: + if (!ctx->prog->aux->verifier_zext) + emit(rv_addi(hi(rd), RV_REG_ZERO, 0), ctx); + break; + case 64: + /* Do nothing. */ + break; + default: + pr_err("bpf-jit: BPF_END imm %d invalid\n", imm); + return -1; + } + + bpf_put_reg64(dst, rd, ctx); + break; + } + + case BPF_ALU | BPF_END | BPF_FROM_BE: + { + const s8 *rd = bpf_get_reg64(dst, tmp1, ctx); + + switch (imm) { + case 16: + emit_rev16(lo(rd), ctx); + if (!ctx->prog->aux->verifier_zext) + emit(rv_addi(hi(rd), RV_REG_ZERO, 0), ctx); + break; + case 32: + emit_rev32(lo(rd), ctx); + if (!ctx->prog->aux->verifier_zext) + emit(rv_addi(hi(rd), RV_REG_ZERO, 0), ctx); + break; + case 64: + /* Swap upper and lower halves. */ + emit(rv_addi(RV_REG_T0, lo(rd), 0), ctx); + emit(rv_addi(lo(rd), hi(rd), 0), ctx); + emit(rv_addi(hi(rd), RV_REG_T0, 0), ctx); + + /* Swap each half. */ + emit_rev32(lo(rd), ctx); + emit_rev32(hi(rd), ctx); + break; + default: + pr_err("bpf-jit: BPF_END imm %d invalid\n", imm); + return -1; + } + + bpf_put_reg64(dst, rd, ctx); + break; + } + + case BPF_JMP | BPF_JA: + rvoff = rv_offset(i, off, ctx); + emit_jump_and_link(RV_REG_ZERO, rvoff, false, ctx); + break; + + case BPF_JMP | BPF_CALL: + { + bool fixed; + int ret; + u64 addr; + + ret = bpf_jit_get_func_addr(ctx->prog, insn, extra_pass, &addr, + &fixed); + if (ret < 0) + return ret; + emit_call(fixed, addr, ctx); + break; + } + + case BPF_JMP | BPF_TAIL_CALL: + if (emit_bpf_tail_call(i, ctx)) + return -1; + break; + + case BPF_JMP | BPF_JEQ | BPF_X: + case BPF_JMP | BPF_JEQ | BPF_K: + case BPF_JMP32 | BPF_JEQ | BPF_X: + case BPF_JMP32 | BPF_JEQ | BPF_K: + + case BPF_JMP | BPF_JNE | BPF_X: + case BPF_JMP | BPF_JNE | BPF_K: + case BPF_JMP32 | BPF_JNE | BPF_X: + case BPF_JMP32 | BPF_JNE | BPF_K: + + case BPF_JMP | BPF_JLE | BPF_X: + case BPF_JMP | BPF_JLE | BPF_K: + case BPF_JMP32 | BPF_JLE | BPF_X: + case BPF_JMP32 | BPF_JLE | BPF_K: + + case BPF_JMP | BPF_JLT | BPF_X: + case BPF_JMP | BPF_JLT | BPF_K: + case BPF_JMP32 | BPF_JLT | BPF_X: + case BPF_JMP32 | BPF_JLT | BPF_K: + + case BPF_JMP | BPF_JGE | BPF_X: + case BPF_JMP | BPF_JGE | BPF_K: + case BPF_JMP32 | BPF_JGE | BPF_X: + case BPF_JMP32 | BPF_JGE | BPF_K: + + case BPF_JMP | BPF_JGT | BPF_X: + case BPF_JMP | BPF_JGT | BPF_K: + case BPF_JMP32 | BPF_JGT | BPF_X: + case BPF_JMP32 | BPF_JGT | BPF_K: + + case BPF_JMP | BPF_JSLE | BPF_X: + case BPF_JMP | BPF_JSLE | BPF_K: + case BPF_JMP32 | BPF_JSLE | BPF_X: + case BPF_JMP32 | BPF_JSLE | BPF_K: + + case BPF_JMP | BPF_JSLT | BPF_X: + case BPF_JMP | BPF_JSLT | BPF_K: + case BPF_JMP32 | BPF_JSLT | BPF_X: + case BPF_JMP32 | BPF_JSLT | BPF_K: + + case BPF_JMP | BPF_JSGE | BPF_X: + case BPF_JMP | BPF_JSGE | BPF_K: + case BPF_JMP32 | BPF_JSGE | BPF_X: + case BPF_JMP32 | BPF_JSGE | BPF_K: + + case BPF_JMP | BPF_JSGT | BPF_X: + case BPF_JMP | BPF_JSGT | BPF_K: + case BPF_JMP32 | BPF_JSGT | BPF_X: + case BPF_JMP32 | BPF_JSGT | BPF_K: + + case BPF_JMP | BPF_JSET | BPF_X: + case BPF_JMP | BPF_JSET | BPF_K: + case BPF_JMP32 | BPF_JSET | BPF_X: + case BPF_JMP32 | BPF_JSET | BPF_K: + rvoff = rv_offset(i, off, ctx); + if (BPF_SRC(code) == BPF_K) { + s = ctx->ninsns; + emit_imm32(tmp2, imm, ctx); + src = tmp2; + e = ctx->ninsns; + rvoff -= ninsns_rvoff(e - s); + } + + if (is64) + emit_branch_r64(dst, src, rvoff, ctx, BPF_OP(code)); + else + emit_branch_r32(dst, src, rvoff, ctx, BPF_OP(code)); + break; + + case BPF_JMP | BPF_EXIT: + if (i == ctx->prog->len - 1) + break; + + rvoff = epilogue_offset(ctx); + emit_jump_and_link(RV_REG_ZERO, rvoff, false, ctx); + break; + + case BPF_LD | BPF_IMM | BPF_DW: + { + struct bpf_insn insn1 = insn[1]; + s32 imm_lo = imm; + s32 imm_hi = insn1.imm; + const s8 *rd = bpf_get_reg64(dst, tmp1, ctx); + + emit_imm64(rd, imm_hi, imm_lo, ctx); + bpf_put_reg64(dst, rd, ctx); + return 1; + } + + case BPF_LDX | BPF_MEM | BPF_B: + case BPF_LDX | BPF_MEM | BPF_H: + case BPF_LDX | BPF_MEM | BPF_W: + case BPF_LDX | BPF_MEM | BPF_DW: + if (emit_load_r64(dst, src, off, ctx, BPF_SIZE(code))) + return -1; + break; + + /* speculation barrier */ + case BPF_ST | BPF_NOSPEC: + break; + + case BPF_ST | BPF_MEM | BPF_B: + case BPF_ST | BPF_MEM | BPF_H: + case BPF_ST | BPF_MEM | BPF_W: + case BPF_ST | BPF_MEM | BPF_DW: + + case BPF_STX | BPF_MEM | BPF_B: + case BPF_STX | BPF_MEM | BPF_H: + case BPF_STX | BPF_MEM | BPF_W: + case BPF_STX | BPF_MEM | BPF_DW: + if (BPF_CLASS(code) == BPF_ST) { + emit_imm32(tmp2, imm, ctx); + src = tmp2; + } + + if (emit_store_r64(dst, src, off, ctx, BPF_SIZE(code), + BPF_MODE(code))) + return -1; + break; + + case BPF_STX | BPF_ATOMIC | BPF_W: + if (insn->imm != BPF_ADD) { + pr_info_once( + "bpf-jit: not supported: atomic operation %02x ***\n", + insn->imm); + return -EFAULT; + } + + if (emit_store_r64(dst, src, off, ctx, BPF_SIZE(code), + BPF_MODE(code))) + return -1; + break; + + /* No hardware support for 8-byte atomics in RV32. */ + case BPF_STX | BPF_ATOMIC | BPF_DW: + /* Fallthrough. */ + +notsupported: + pr_info_once("bpf-jit: not supported: opcode %02x ***\n", code); + return -EFAULT; + + default: + pr_err("bpf-jit: unknown opcode %02x\n", code); + return -EINVAL; + } + + return 0; +} + +void bpf_jit_build_prologue(struct rv_jit_context *ctx) +{ + const s8 *fp = bpf2rv32[BPF_REG_FP]; + const s8 *r1 = bpf2rv32[BPF_REG_1]; + int stack_adjust = 0; + int bpf_stack_adjust = + round_up(ctx->prog->aux->stack_depth, STACK_ALIGN); + + /* Make space for callee-saved registers. */ + stack_adjust += NR_SAVED_REGISTERS * sizeof(u32); + /* Make space for BPF registers on stack. */ + stack_adjust += BPF_JIT_SCRATCH_REGS * sizeof(u32); + /* Make space for BPF stack. */ + stack_adjust += bpf_stack_adjust; + /* Round up for stack alignment. */ + stack_adjust = round_up(stack_adjust, STACK_ALIGN); + + /* + * The first instruction sets the tail-call-counter (TCC) register. + * This instruction is skipped by tail calls. + */ + emit(rv_addi(RV_REG_TCC, RV_REG_ZERO, MAX_TAIL_CALL_CNT), ctx); + + emit(rv_addi(RV_REG_SP, RV_REG_SP, -stack_adjust), ctx); + + /* Save callee-save registers. */ + emit(rv_sw(RV_REG_SP, stack_adjust - 4, RV_REG_RA), ctx); + emit(rv_sw(RV_REG_SP, stack_adjust - 8, RV_REG_FP), ctx); + emit(rv_sw(RV_REG_SP, stack_adjust - 12, RV_REG_S1), ctx); + emit(rv_sw(RV_REG_SP, stack_adjust - 16, RV_REG_S2), ctx); + emit(rv_sw(RV_REG_SP, stack_adjust - 20, RV_REG_S3), ctx); + emit(rv_sw(RV_REG_SP, stack_adjust - 24, RV_REG_S4), ctx); + emit(rv_sw(RV_REG_SP, stack_adjust - 28, RV_REG_S5), ctx); + emit(rv_sw(RV_REG_SP, stack_adjust - 32, RV_REG_S6), ctx); + emit(rv_sw(RV_REG_SP, stack_adjust - 36, RV_REG_S7), ctx); + + /* Set fp: used as the base address for stacked BPF registers. */ + emit(rv_addi(RV_REG_FP, RV_REG_SP, stack_adjust), ctx); + + /* Set up BPF frame pointer. */ + emit(rv_addi(lo(fp), RV_REG_SP, bpf_stack_adjust), ctx); + emit(rv_addi(hi(fp), RV_REG_ZERO, 0), ctx); + + /* Set up BPF context pointer. */ + emit(rv_addi(lo(r1), RV_REG_A0, 0), ctx); + emit(rv_addi(hi(r1), RV_REG_ZERO, 0), ctx); + + ctx->stack_size = stack_adjust; +} + +void bpf_jit_build_epilogue(struct rv_jit_context *ctx) +{ + __build_epilogue(false, ctx); +} diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c new file mode 100644 index 000000000..8f5d3c57d --- /dev/null +++ b/arch/riscv/net/bpf_jit_comp64.c @@ -0,0 +1,1353 @@ +// SPDX-License-Identifier: GPL-2.0 +/* BPF JIT compiler for RV64G + * + * Copyright(c) 2019 Björn Töpel <bjorn.topel@gmail.com> + * + */ + +#include <linux/bitfield.h> +#include <linux/bpf.h> +#include <linux/filter.h> +#include "bpf_jit.h" + +#define RV_REG_TCC RV_REG_A6 +#define RV_REG_TCC_SAVED RV_REG_S6 /* Store A6 in S6 if program do calls */ + +static const int regmap[] = { + [BPF_REG_0] = RV_REG_A5, + [BPF_REG_1] = RV_REG_A0, + [BPF_REG_2] = RV_REG_A1, + [BPF_REG_3] = RV_REG_A2, + [BPF_REG_4] = RV_REG_A3, + [BPF_REG_5] = RV_REG_A4, + [BPF_REG_6] = RV_REG_S1, + [BPF_REG_7] = RV_REG_S2, + [BPF_REG_8] = RV_REG_S3, + [BPF_REG_9] = RV_REG_S4, + [BPF_REG_FP] = RV_REG_S5, + [BPF_REG_AX] = RV_REG_T0, +}; + +static const int pt_regmap[] = { + [RV_REG_A0] = offsetof(struct pt_regs, a0), + [RV_REG_A1] = offsetof(struct pt_regs, a1), + [RV_REG_A2] = offsetof(struct pt_regs, a2), + [RV_REG_A3] = offsetof(struct pt_regs, a3), + [RV_REG_A4] = offsetof(struct pt_regs, a4), + [RV_REG_A5] = offsetof(struct pt_regs, a5), + [RV_REG_S1] = offsetof(struct pt_regs, s1), + [RV_REG_S2] = offsetof(struct pt_regs, s2), + [RV_REG_S3] = offsetof(struct pt_regs, s3), + [RV_REG_S4] = offsetof(struct pt_regs, s4), + [RV_REG_S5] = offsetof(struct pt_regs, s5), + [RV_REG_T0] = offsetof(struct pt_regs, t0), +}; + +enum { + RV_CTX_F_SEEN_TAIL_CALL = 0, + RV_CTX_F_SEEN_CALL = RV_REG_RA, + RV_CTX_F_SEEN_S1 = RV_REG_S1, + RV_CTX_F_SEEN_S2 = RV_REG_S2, + RV_CTX_F_SEEN_S3 = RV_REG_S3, + RV_CTX_F_SEEN_S4 = RV_REG_S4, + RV_CTX_F_SEEN_S5 = RV_REG_S5, + RV_CTX_F_SEEN_S6 = RV_REG_S6, +}; + +static u8 bpf_to_rv_reg(int bpf_reg, struct rv_jit_context *ctx) +{ + u8 reg = regmap[bpf_reg]; + + switch (reg) { + case RV_CTX_F_SEEN_S1: + case RV_CTX_F_SEEN_S2: + case RV_CTX_F_SEEN_S3: + case RV_CTX_F_SEEN_S4: + case RV_CTX_F_SEEN_S5: + case RV_CTX_F_SEEN_S6: + __set_bit(reg, &ctx->flags); + } + return reg; +}; + +static bool seen_reg(int reg, struct rv_jit_context *ctx) +{ + switch (reg) { + case RV_CTX_F_SEEN_CALL: + case RV_CTX_F_SEEN_S1: + case RV_CTX_F_SEEN_S2: + case RV_CTX_F_SEEN_S3: + case RV_CTX_F_SEEN_S4: + case RV_CTX_F_SEEN_S5: + case RV_CTX_F_SEEN_S6: + return test_bit(reg, &ctx->flags); + } + return false; +} + +static void mark_fp(struct rv_jit_context *ctx) +{ + __set_bit(RV_CTX_F_SEEN_S5, &ctx->flags); +} + +static void mark_call(struct rv_jit_context *ctx) +{ + __set_bit(RV_CTX_F_SEEN_CALL, &ctx->flags); +} + +static bool seen_call(struct rv_jit_context *ctx) +{ + return test_bit(RV_CTX_F_SEEN_CALL, &ctx->flags); +} + +static void mark_tail_call(struct rv_jit_context *ctx) +{ + __set_bit(RV_CTX_F_SEEN_TAIL_CALL, &ctx->flags); +} + +static bool seen_tail_call(struct rv_jit_context *ctx) +{ + return test_bit(RV_CTX_F_SEEN_TAIL_CALL, &ctx->flags); +} + +static u8 rv_tail_call_reg(struct rv_jit_context *ctx) +{ + mark_tail_call(ctx); + + if (seen_call(ctx)) { + __set_bit(RV_CTX_F_SEEN_S6, &ctx->flags); + return RV_REG_S6; + } + return RV_REG_A6; +} + +static bool is_32b_int(s64 val) +{ + return -(1L << 31) <= val && val < (1L << 31); +} + +static bool in_auipc_jalr_range(s64 val) +{ + /* + * auipc+jalr can reach any signed PC-relative offset in the range + * [-2^31 - 2^11, 2^31 - 2^11). + */ + return (-(1L << 31) - (1L << 11)) <= val && + val < ((1L << 31) - (1L << 11)); +} + +/* Emit fixed-length instructions for address */ +static int emit_addr(u8 rd, u64 addr, bool extra_pass, struct rv_jit_context *ctx) +{ + u64 ip = (u64)(ctx->insns + ctx->ninsns); + s64 off = addr - ip; + s64 upper = (off + (1 << 11)) >> 12; + s64 lower = off & 0xfff; + + if (extra_pass && !in_auipc_jalr_range(off)) { + pr_err("bpf-jit: target offset 0x%llx is out of range\n", off); + return -ERANGE; + } + + emit(rv_auipc(rd, upper), ctx); + emit(rv_addi(rd, rd, lower), ctx); + return 0; +} + +/* Emit variable-length instructions for 32-bit and 64-bit imm */ +static void emit_imm(u8 rd, s64 val, struct rv_jit_context *ctx) +{ + /* Note that the immediate from the add is sign-extended, + * which means that we need to compensate this by adding 2^12, + * when the 12th bit is set. A simpler way of doing this, and + * getting rid of the check, is to just add 2**11 before the + * shift. The "Loading a 32-Bit constant" example from the + * "Computer Organization and Design, RISC-V edition" book by + * Patterson/Hennessy highlights this fact. + * + * This also means that we need to process LSB to MSB. + */ + s64 upper = (val + (1 << 11)) >> 12; + /* Sign-extend lower 12 bits to 64 bits since immediates for li, addiw, + * and addi are signed and RVC checks will perform signed comparisons. + */ + s64 lower = ((val & 0xfff) << 52) >> 52; + int shift; + + if (is_32b_int(val)) { + if (upper) + emit_lui(rd, upper, ctx); + + if (!upper) { + emit_li(rd, lower, ctx); + return; + } + + emit_addiw(rd, rd, lower, ctx); + return; + } + + shift = __ffs(upper); + upper >>= shift; + shift += 12; + + emit_imm(rd, upper, ctx); + + emit_slli(rd, rd, shift, ctx); + if (lower) + emit_addi(rd, rd, lower, ctx); +} + +static void __build_epilogue(bool is_tail_call, struct rv_jit_context *ctx) +{ + int stack_adjust = ctx->stack_size, store_offset = stack_adjust - 8; + + if (seen_reg(RV_REG_RA, ctx)) { + emit_ld(RV_REG_RA, store_offset, RV_REG_SP, ctx); + store_offset -= 8; + } + emit_ld(RV_REG_FP, store_offset, RV_REG_SP, ctx); + store_offset -= 8; + if (seen_reg(RV_REG_S1, ctx)) { + emit_ld(RV_REG_S1, store_offset, RV_REG_SP, ctx); + store_offset -= 8; + } + if (seen_reg(RV_REG_S2, ctx)) { + emit_ld(RV_REG_S2, store_offset, RV_REG_SP, ctx); + store_offset -= 8; + } + if (seen_reg(RV_REG_S3, ctx)) { + emit_ld(RV_REG_S3, store_offset, RV_REG_SP, ctx); + store_offset -= 8; + } + if (seen_reg(RV_REG_S4, ctx)) { + emit_ld(RV_REG_S4, store_offset, RV_REG_SP, ctx); + store_offset -= 8; + } + if (seen_reg(RV_REG_S5, ctx)) { + emit_ld(RV_REG_S5, store_offset, RV_REG_SP, ctx); + store_offset -= 8; + } + if (seen_reg(RV_REG_S6, ctx)) { + emit_ld(RV_REG_S6, store_offset, RV_REG_SP, ctx); + store_offset -= 8; + } + + emit_addi(RV_REG_SP, RV_REG_SP, stack_adjust, ctx); + /* Set return value. */ + if (!is_tail_call) + emit_addiw(RV_REG_A0, RV_REG_A5, 0, ctx); + emit_jalr(RV_REG_ZERO, is_tail_call ? RV_REG_T3 : RV_REG_RA, + is_tail_call ? 4 : 0, /* skip TCC init */ + ctx); +} + +static void emit_bcc(u8 cond, u8 rd, u8 rs, int rvoff, + struct rv_jit_context *ctx) +{ + switch (cond) { + case BPF_JEQ: + emit(rv_beq(rd, rs, rvoff >> 1), ctx); + return; + case BPF_JGT: + emit(rv_bltu(rs, rd, rvoff >> 1), ctx); + return; + case BPF_JLT: + emit(rv_bltu(rd, rs, rvoff >> 1), ctx); + return; + case BPF_JGE: + emit(rv_bgeu(rd, rs, rvoff >> 1), ctx); + return; + case BPF_JLE: + emit(rv_bgeu(rs, rd, rvoff >> 1), ctx); + return; + case BPF_JNE: + emit(rv_bne(rd, rs, rvoff >> 1), ctx); + return; + case BPF_JSGT: + emit(rv_blt(rs, rd, rvoff >> 1), ctx); + return; + case BPF_JSLT: + emit(rv_blt(rd, rs, rvoff >> 1), ctx); + return; + case BPF_JSGE: + emit(rv_bge(rd, rs, rvoff >> 1), ctx); + return; + case BPF_JSLE: + emit(rv_bge(rs, rd, rvoff >> 1), ctx); + } +} + +static void emit_branch(u8 cond, u8 rd, u8 rs, int rvoff, + struct rv_jit_context *ctx) +{ + s64 upper, lower; + + if (is_13b_int(rvoff)) { + emit_bcc(cond, rd, rs, rvoff, ctx); + return; + } + + /* Adjust for jal */ + rvoff -= 4; + + /* Transform, e.g.: + * bne rd,rs,foo + * to + * beq rd,rs,<.L1> + * (auipc foo) + * jal(r) foo + * .L1 + */ + cond = invert_bpf_cond(cond); + if (is_21b_int(rvoff)) { + emit_bcc(cond, rd, rs, 8, ctx); + emit(rv_jal(RV_REG_ZERO, rvoff >> 1), ctx); + return; + } + + /* 32b No need for an additional rvoff adjustment, since we + * get that from the auipc at PC', where PC = PC' + 4. + */ + upper = (rvoff + (1 << 11)) >> 12; + lower = rvoff & 0xfff; + + emit_bcc(cond, rd, rs, 12, ctx); + emit(rv_auipc(RV_REG_T1, upper), ctx); + emit(rv_jalr(RV_REG_ZERO, RV_REG_T1, lower), ctx); +} + +static void emit_zext_32(u8 reg, struct rv_jit_context *ctx) +{ + emit_slli(reg, reg, 32, ctx); + emit_srli(reg, reg, 32, ctx); +} + +static int emit_bpf_tail_call(int insn, struct rv_jit_context *ctx) +{ + int tc_ninsn, off, start_insn = ctx->ninsns; + u8 tcc = rv_tail_call_reg(ctx); + + /* a0: &ctx + * a1: &array + * a2: index + * + * if (index >= array->map.max_entries) + * goto out; + */ + tc_ninsn = insn ? ctx->offset[insn] - ctx->offset[insn - 1] : + ctx->offset[0]; + emit_zext_32(RV_REG_A2, ctx); + + off = offsetof(struct bpf_array, map.max_entries); + if (is_12b_check(off, insn)) + return -1; + emit(rv_lwu(RV_REG_T1, off, RV_REG_A1), ctx); + off = ninsns_rvoff(tc_ninsn - (ctx->ninsns - start_insn)); + emit_branch(BPF_JGE, RV_REG_A2, RV_REG_T1, off, ctx); + + /* if (--TCC < 0) + * goto out; + */ + emit_addi(RV_REG_TCC, tcc, -1, ctx); + off = ninsns_rvoff(tc_ninsn - (ctx->ninsns - start_insn)); + emit_branch(BPF_JSLT, RV_REG_TCC, RV_REG_ZERO, off, ctx); + + /* prog = array->ptrs[index]; + * if (!prog) + * goto out; + */ + emit_slli(RV_REG_T2, RV_REG_A2, 3, ctx); + emit_add(RV_REG_T2, RV_REG_T2, RV_REG_A1, ctx); + off = offsetof(struct bpf_array, ptrs); + if (is_12b_check(off, insn)) + return -1; + emit_ld(RV_REG_T2, off, RV_REG_T2, ctx); + off = ninsns_rvoff(tc_ninsn - (ctx->ninsns - start_insn)); + emit_branch(BPF_JEQ, RV_REG_T2, RV_REG_ZERO, off, ctx); + + /* goto *(prog->bpf_func + 4); */ + off = offsetof(struct bpf_prog, bpf_func); + if (is_12b_check(off, insn)) + return -1; + emit_ld(RV_REG_T3, off, RV_REG_T2, ctx); + __build_epilogue(true, ctx); + return 0; +} + +static void init_regs(u8 *rd, u8 *rs, const struct bpf_insn *insn, + struct rv_jit_context *ctx) +{ + u8 code = insn->code; + + switch (code) { + case BPF_JMP | BPF_JA: + case BPF_JMP | BPF_CALL: + case BPF_JMP | BPF_EXIT: + case BPF_JMP | BPF_TAIL_CALL: + break; + default: + *rd = bpf_to_rv_reg(insn->dst_reg, ctx); + } + + if (code & (BPF_ALU | BPF_X) || code & (BPF_ALU64 | BPF_X) || + code & (BPF_JMP | BPF_X) || code & (BPF_JMP32 | BPF_X) || + code & BPF_LDX || code & BPF_STX) + *rs = bpf_to_rv_reg(insn->src_reg, ctx); +} + +static void emit_zext_32_rd_rs(u8 *rd, u8 *rs, struct rv_jit_context *ctx) +{ + emit_mv(RV_REG_T2, *rd, ctx); + emit_zext_32(RV_REG_T2, ctx); + emit_mv(RV_REG_T1, *rs, ctx); + emit_zext_32(RV_REG_T1, ctx); + *rd = RV_REG_T2; + *rs = RV_REG_T1; +} + +static void emit_sext_32_rd_rs(u8 *rd, u8 *rs, struct rv_jit_context *ctx) +{ + emit_addiw(RV_REG_T2, *rd, 0, ctx); + emit_addiw(RV_REG_T1, *rs, 0, ctx); + *rd = RV_REG_T2; + *rs = RV_REG_T1; +} + +static void emit_zext_32_rd_t1(u8 *rd, struct rv_jit_context *ctx) +{ + emit_mv(RV_REG_T2, *rd, ctx); + emit_zext_32(RV_REG_T2, ctx); + emit_zext_32(RV_REG_T1, ctx); + *rd = RV_REG_T2; +} + +static void emit_sext_32_rd(u8 *rd, struct rv_jit_context *ctx) +{ + emit_addiw(RV_REG_T2, *rd, 0, ctx); + *rd = RV_REG_T2; +} + +static int emit_jump_and_link(u8 rd, s64 rvoff, bool fixed_addr, + struct rv_jit_context *ctx) +{ + s64 upper, lower; + + if (rvoff && fixed_addr && is_21b_int(rvoff)) { + emit(rv_jal(rd, rvoff >> 1), ctx); + return 0; + } else if (in_auipc_jalr_range(rvoff)) { + upper = (rvoff + (1 << 11)) >> 12; + lower = rvoff & 0xfff; + emit(rv_auipc(RV_REG_T1, upper), ctx); + emit(rv_jalr(rd, RV_REG_T1, lower), ctx); + return 0; + } + + pr_err("bpf-jit: target offset 0x%llx is out of range\n", rvoff); + return -ERANGE; +} + +static bool is_signed_bpf_cond(u8 cond) +{ + return cond == BPF_JSGT || cond == BPF_JSLT || + cond == BPF_JSGE || cond == BPF_JSLE; +} + +static int emit_call(u64 addr, bool fixed_addr, struct rv_jit_context *ctx) +{ + s64 off = 0; + u64 ip; + + if (addr && ctx->insns) { + ip = (u64)(long)(ctx->insns + ctx->ninsns); + off = addr - ip; + } + + return emit_jump_and_link(RV_REG_RA, off, fixed_addr, ctx); +} + +static void emit_atomic(u8 rd, u8 rs, s16 off, s32 imm, bool is64, + struct rv_jit_context *ctx) +{ + u8 r0; + int jmp_offset; + + if (off) { + if (is_12b_int(off)) { + emit_addi(RV_REG_T1, rd, off, ctx); + } else { + emit_imm(RV_REG_T1, off, ctx); + emit_add(RV_REG_T1, RV_REG_T1, rd, ctx); + } + rd = RV_REG_T1; + } + + switch (imm) { + /* lock *(u32/u64 *)(dst_reg + off16) <op>= src_reg */ + case BPF_ADD: + emit(is64 ? rv_amoadd_d(RV_REG_ZERO, rs, rd, 0, 0) : + rv_amoadd_w(RV_REG_ZERO, rs, rd, 0, 0), ctx); + break; + case BPF_AND: + emit(is64 ? rv_amoand_d(RV_REG_ZERO, rs, rd, 0, 0) : + rv_amoand_w(RV_REG_ZERO, rs, rd, 0, 0), ctx); + break; + case BPF_OR: + emit(is64 ? rv_amoor_d(RV_REG_ZERO, rs, rd, 0, 0) : + rv_amoor_w(RV_REG_ZERO, rs, rd, 0, 0), ctx); + break; + case BPF_XOR: + emit(is64 ? rv_amoxor_d(RV_REG_ZERO, rs, rd, 0, 0) : + rv_amoxor_w(RV_REG_ZERO, rs, rd, 0, 0), ctx); + break; + /* src_reg = atomic_fetch_<op>(dst_reg + off16, src_reg) */ + case BPF_ADD | BPF_FETCH: + emit(is64 ? rv_amoadd_d(rs, rs, rd, 0, 0) : + rv_amoadd_w(rs, rs, rd, 0, 0), ctx); + if (!is64) + emit_zext_32(rs, ctx); + break; + case BPF_AND | BPF_FETCH: + emit(is64 ? rv_amoand_d(rs, rs, rd, 0, 0) : + rv_amoand_w(rs, rs, rd, 0, 0), ctx); + if (!is64) + emit_zext_32(rs, ctx); + break; + case BPF_OR | BPF_FETCH: + emit(is64 ? rv_amoor_d(rs, rs, rd, 0, 0) : + rv_amoor_w(rs, rs, rd, 0, 0), ctx); + if (!is64) + emit_zext_32(rs, ctx); + break; + case BPF_XOR | BPF_FETCH: + emit(is64 ? rv_amoxor_d(rs, rs, rd, 0, 0) : + rv_amoxor_w(rs, rs, rd, 0, 0), ctx); + if (!is64) + emit_zext_32(rs, ctx); + break; + /* src_reg = atomic_xchg(dst_reg + off16, src_reg); */ + case BPF_XCHG: + emit(is64 ? rv_amoswap_d(rs, rs, rd, 0, 0) : + rv_amoswap_w(rs, rs, rd, 0, 0), ctx); + if (!is64) + emit_zext_32(rs, ctx); + break; + /* r0 = atomic_cmpxchg(dst_reg + off16, r0, src_reg); */ + case BPF_CMPXCHG: + r0 = bpf_to_rv_reg(BPF_REG_0, ctx); + emit(is64 ? rv_addi(RV_REG_T2, r0, 0) : + rv_addiw(RV_REG_T2, r0, 0), ctx); + emit(is64 ? rv_lr_d(r0, 0, rd, 0, 0) : + rv_lr_w(r0, 0, rd, 0, 0), ctx); + jmp_offset = ninsns_rvoff(8); + emit(rv_bne(RV_REG_T2, r0, jmp_offset >> 1), ctx); + emit(is64 ? rv_sc_d(RV_REG_T3, rs, rd, 0, 0) : + rv_sc_w(RV_REG_T3, rs, rd, 0, 0), ctx); + jmp_offset = ninsns_rvoff(-6); + emit(rv_bne(RV_REG_T3, 0, jmp_offset >> 1), ctx); + emit(rv_fence(0x3, 0x3), ctx); + break; + } +} + +#define BPF_FIXUP_OFFSET_MASK GENMASK(26, 0) +#define BPF_FIXUP_REG_MASK GENMASK(31, 27) + +bool ex_handler_bpf(const struct exception_table_entry *ex, + struct pt_regs *regs) +{ + off_t offset = FIELD_GET(BPF_FIXUP_OFFSET_MASK, ex->fixup); + int regs_offset = FIELD_GET(BPF_FIXUP_REG_MASK, ex->fixup); + + *(unsigned long *)((void *)regs + pt_regmap[regs_offset]) = 0; + regs->epc = (unsigned long)&ex->fixup - offset; + + return true; +} + +/* For accesses to BTF pointers, add an entry to the exception table */ +static int add_exception_handler(const struct bpf_insn *insn, + struct rv_jit_context *ctx, + int dst_reg, int insn_len) +{ + struct exception_table_entry *ex; + unsigned long pc; + off_t offset; + + if (!ctx->insns || !ctx->prog->aux->extable || BPF_MODE(insn->code) != BPF_PROBE_MEM) + return 0; + + if (WARN_ON_ONCE(ctx->nexentries >= ctx->prog->aux->num_exentries)) + return -EINVAL; + + if (WARN_ON_ONCE(insn_len > ctx->ninsns)) + return -EINVAL; + + if (WARN_ON_ONCE(!rvc_enabled() && insn_len == 1)) + return -EINVAL; + + ex = &ctx->prog->aux->extable[ctx->nexentries]; + pc = (unsigned long)&ctx->insns[ctx->ninsns - insn_len]; + + offset = pc - (long)&ex->insn; + if (WARN_ON_ONCE(offset >= 0 || offset < INT_MIN)) + return -ERANGE; + ex->insn = offset; + + /* + * Since the extable follows the program, the fixup offset is always + * negative and limited to BPF_JIT_REGION_SIZE. Store a positive value + * to keep things simple, and put the destination register in the upper + * bits. We don't need to worry about buildtime or runtime sort + * modifying the upper bits because the table is already sorted, and + * isn't part of the main exception table. + */ + offset = (long)&ex->fixup - (pc + insn_len * sizeof(u16)); + if (!FIELD_FIT(BPF_FIXUP_OFFSET_MASK, offset)) + return -ERANGE; + + ex->fixup = FIELD_PREP(BPF_FIXUP_OFFSET_MASK, offset) | + FIELD_PREP(BPF_FIXUP_REG_MASK, dst_reg); + ex->type = EX_TYPE_BPF; + + ctx->nexentries++; + return 0; +} + +int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, + bool extra_pass) +{ + bool is64 = BPF_CLASS(insn->code) == BPF_ALU64 || + BPF_CLASS(insn->code) == BPF_JMP; + int s, e, rvoff, ret, i = insn - ctx->prog->insnsi; + struct bpf_prog_aux *aux = ctx->prog->aux; + u8 rd = -1, rs = -1, code = insn->code; + s16 off = insn->off; + s32 imm = insn->imm; + + init_regs(&rd, &rs, insn, ctx); + + switch (code) { + /* dst = src */ + case BPF_ALU | BPF_MOV | BPF_X: + case BPF_ALU64 | BPF_MOV | BPF_X: + if (imm == 1) { + /* Special mov32 for zext */ + emit_zext_32(rd, ctx); + break; + } + emit_mv(rd, rs, ctx); + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + + /* dst = dst OP src */ + case BPF_ALU | BPF_ADD | BPF_X: + case BPF_ALU64 | BPF_ADD | BPF_X: + emit_add(rd, rd, rs, ctx); + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + case BPF_ALU | BPF_SUB | BPF_X: + case BPF_ALU64 | BPF_SUB | BPF_X: + if (is64) + emit_sub(rd, rd, rs, ctx); + else + emit_subw(rd, rd, rs, ctx); + + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + case BPF_ALU | BPF_AND | BPF_X: + case BPF_ALU64 | BPF_AND | BPF_X: + emit_and(rd, rd, rs, ctx); + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + case BPF_ALU | BPF_OR | BPF_X: + case BPF_ALU64 | BPF_OR | BPF_X: + emit_or(rd, rd, rs, ctx); + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + case BPF_ALU | BPF_XOR | BPF_X: + case BPF_ALU64 | BPF_XOR | BPF_X: + emit_xor(rd, rd, rs, ctx); + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + case BPF_ALU | BPF_MUL | BPF_X: + case BPF_ALU64 | BPF_MUL | BPF_X: + emit(is64 ? rv_mul(rd, rd, rs) : rv_mulw(rd, rd, rs), ctx); + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + case BPF_ALU | BPF_DIV | BPF_X: + case BPF_ALU64 | BPF_DIV | BPF_X: + emit(is64 ? rv_divu(rd, rd, rs) : rv_divuw(rd, rd, rs), ctx); + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + case BPF_ALU | BPF_MOD | BPF_X: + case BPF_ALU64 | BPF_MOD | BPF_X: + emit(is64 ? rv_remu(rd, rd, rs) : rv_remuw(rd, rd, rs), ctx); + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + case BPF_ALU | BPF_LSH | BPF_X: + case BPF_ALU64 | BPF_LSH | BPF_X: + emit(is64 ? rv_sll(rd, rd, rs) : rv_sllw(rd, rd, rs), ctx); + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + case BPF_ALU | BPF_RSH | BPF_X: + case BPF_ALU64 | BPF_RSH | BPF_X: + emit(is64 ? rv_srl(rd, rd, rs) : rv_srlw(rd, rd, rs), ctx); + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + case BPF_ALU | BPF_ARSH | BPF_X: + case BPF_ALU64 | BPF_ARSH | BPF_X: + emit(is64 ? rv_sra(rd, rd, rs) : rv_sraw(rd, rd, rs), ctx); + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + + /* dst = -dst */ + case BPF_ALU | BPF_NEG: + case BPF_ALU64 | BPF_NEG: + emit_sub(rd, RV_REG_ZERO, rd, ctx); + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + + /* dst = BSWAP##imm(dst) */ + case BPF_ALU | BPF_END | BPF_FROM_LE: + switch (imm) { + case 16: + emit_slli(rd, rd, 48, ctx); + emit_srli(rd, rd, 48, ctx); + break; + case 32: + if (!aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + case 64: + /* Do nothing */ + break; + } + break; + + case BPF_ALU | BPF_END | BPF_FROM_BE: + emit_li(RV_REG_T2, 0, ctx); + + emit_andi(RV_REG_T1, rd, 0xff, ctx); + emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx); + emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx); + emit_srli(rd, rd, 8, ctx); + if (imm == 16) + goto out_be; + + emit_andi(RV_REG_T1, rd, 0xff, ctx); + emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx); + emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx); + emit_srli(rd, rd, 8, ctx); + + emit_andi(RV_REG_T1, rd, 0xff, ctx); + emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx); + emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx); + emit_srli(rd, rd, 8, ctx); + if (imm == 32) + goto out_be; + + emit_andi(RV_REG_T1, rd, 0xff, ctx); + emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx); + emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx); + emit_srli(rd, rd, 8, ctx); + + emit_andi(RV_REG_T1, rd, 0xff, ctx); + emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx); + emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx); + emit_srli(rd, rd, 8, ctx); + + emit_andi(RV_REG_T1, rd, 0xff, ctx); + emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx); + emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx); + emit_srli(rd, rd, 8, ctx); + + emit_andi(RV_REG_T1, rd, 0xff, ctx); + emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx); + emit_slli(RV_REG_T2, RV_REG_T2, 8, ctx); + emit_srli(rd, rd, 8, ctx); +out_be: + emit_andi(RV_REG_T1, rd, 0xff, ctx); + emit_add(RV_REG_T2, RV_REG_T2, RV_REG_T1, ctx); + + emit_mv(rd, RV_REG_T2, ctx); + break; + + /* dst = imm */ + case BPF_ALU | BPF_MOV | BPF_K: + case BPF_ALU64 | BPF_MOV | BPF_K: + emit_imm(rd, imm, ctx); + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + + /* dst = dst OP imm */ + case BPF_ALU | BPF_ADD | BPF_K: + case BPF_ALU64 | BPF_ADD | BPF_K: + if (is_12b_int(imm)) { + emit_addi(rd, rd, imm, ctx); + } else { + emit_imm(RV_REG_T1, imm, ctx); + emit_add(rd, rd, RV_REG_T1, ctx); + } + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + case BPF_ALU | BPF_SUB | BPF_K: + case BPF_ALU64 | BPF_SUB | BPF_K: + if (is_12b_int(-imm)) { + emit_addi(rd, rd, -imm, ctx); + } else { + emit_imm(RV_REG_T1, imm, ctx); + emit_sub(rd, rd, RV_REG_T1, ctx); + } + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + case BPF_ALU | BPF_AND | BPF_K: + case BPF_ALU64 | BPF_AND | BPF_K: + if (is_12b_int(imm)) { + emit_andi(rd, rd, imm, ctx); + } else { + emit_imm(RV_REG_T1, imm, ctx); + emit_and(rd, rd, RV_REG_T1, ctx); + } + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + case BPF_ALU | BPF_OR | BPF_K: + case BPF_ALU64 | BPF_OR | BPF_K: + if (is_12b_int(imm)) { + emit(rv_ori(rd, rd, imm), ctx); + } else { + emit_imm(RV_REG_T1, imm, ctx); + emit_or(rd, rd, RV_REG_T1, ctx); + } + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + case BPF_ALU | BPF_XOR | BPF_K: + case BPF_ALU64 | BPF_XOR | BPF_K: + if (is_12b_int(imm)) { + emit(rv_xori(rd, rd, imm), ctx); + } else { + emit_imm(RV_REG_T1, imm, ctx); + emit_xor(rd, rd, RV_REG_T1, ctx); + } + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + case BPF_ALU | BPF_MUL | BPF_K: + case BPF_ALU64 | BPF_MUL | BPF_K: + emit_imm(RV_REG_T1, imm, ctx); + emit(is64 ? rv_mul(rd, rd, RV_REG_T1) : + rv_mulw(rd, rd, RV_REG_T1), ctx); + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + case BPF_ALU | BPF_DIV | BPF_K: + case BPF_ALU64 | BPF_DIV | BPF_K: + emit_imm(RV_REG_T1, imm, ctx); + emit(is64 ? rv_divu(rd, rd, RV_REG_T1) : + rv_divuw(rd, rd, RV_REG_T1), ctx); + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + case BPF_ALU | BPF_MOD | BPF_K: + case BPF_ALU64 | BPF_MOD | BPF_K: + emit_imm(RV_REG_T1, imm, ctx); + emit(is64 ? rv_remu(rd, rd, RV_REG_T1) : + rv_remuw(rd, rd, RV_REG_T1), ctx); + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + case BPF_ALU | BPF_LSH | BPF_K: + case BPF_ALU64 | BPF_LSH | BPF_K: + emit_slli(rd, rd, imm, ctx); + + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + case BPF_ALU | BPF_RSH | BPF_K: + case BPF_ALU64 | BPF_RSH | BPF_K: + if (is64) + emit_srli(rd, rd, imm, ctx); + else + emit(rv_srliw(rd, rd, imm), ctx); + + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + case BPF_ALU | BPF_ARSH | BPF_K: + case BPF_ALU64 | BPF_ARSH | BPF_K: + if (is64) + emit_srai(rd, rd, imm, ctx); + else + emit(rv_sraiw(rd, rd, imm), ctx); + + if (!is64 && !aux->verifier_zext) + emit_zext_32(rd, ctx); + break; + + /* JUMP off */ + case BPF_JMP | BPF_JA: + rvoff = rv_offset(i, off, ctx); + ret = emit_jump_and_link(RV_REG_ZERO, rvoff, true, ctx); + if (ret) + return ret; + break; + + /* IF (dst COND src) JUMP off */ + case BPF_JMP | BPF_JEQ | BPF_X: + case BPF_JMP32 | BPF_JEQ | BPF_X: + case BPF_JMP | BPF_JGT | BPF_X: + case BPF_JMP32 | BPF_JGT | BPF_X: + case BPF_JMP | BPF_JLT | BPF_X: + case BPF_JMP32 | BPF_JLT | BPF_X: + case BPF_JMP | BPF_JGE | BPF_X: + case BPF_JMP32 | BPF_JGE | BPF_X: + case BPF_JMP | BPF_JLE | BPF_X: + case BPF_JMP32 | BPF_JLE | BPF_X: + case BPF_JMP | BPF_JNE | BPF_X: + case BPF_JMP32 | BPF_JNE | BPF_X: + case BPF_JMP | BPF_JSGT | BPF_X: + case BPF_JMP32 | BPF_JSGT | BPF_X: + case BPF_JMP | BPF_JSLT | BPF_X: + case BPF_JMP32 | BPF_JSLT | BPF_X: + case BPF_JMP | BPF_JSGE | BPF_X: + case BPF_JMP32 | BPF_JSGE | BPF_X: + case BPF_JMP | BPF_JSLE | BPF_X: + case BPF_JMP32 | BPF_JSLE | BPF_X: + case BPF_JMP | BPF_JSET | BPF_X: + case BPF_JMP32 | BPF_JSET | BPF_X: + rvoff = rv_offset(i, off, ctx); + if (!is64) { + s = ctx->ninsns; + if (is_signed_bpf_cond(BPF_OP(code))) + emit_sext_32_rd_rs(&rd, &rs, ctx); + else + emit_zext_32_rd_rs(&rd, &rs, ctx); + e = ctx->ninsns; + + /* Adjust for extra insns */ + rvoff -= ninsns_rvoff(e - s); + } + + if (BPF_OP(code) == BPF_JSET) { + /* Adjust for and */ + rvoff -= 4; + emit_and(RV_REG_T1, rd, rs, ctx); + emit_branch(BPF_JNE, RV_REG_T1, RV_REG_ZERO, rvoff, + ctx); + } else { + emit_branch(BPF_OP(code), rd, rs, rvoff, ctx); + } + break; + + /* IF (dst COND imm) JUMP off */ + case BPF_JMP | BPF_JEQ | BPF_K: + case BPF_JMP32 | BPF_JEQ | BPF_K: + case BPF_JMP | BPF_JGT | BPF_K: + case BPF_JMP32 | BPF_JGT | BPF_K: + case BPF_JMP | BPF_JLT | BPF_K: + case BPF_JMP32 | BPF_JLT | BPF_K: + case BPF_JMP | BPF_JGE | BPF_K: + case BPF_JMP32 | BPF_JGE | BPF_K: + case BPF_JMP | BPF_JLE | BPF_K: + case BPF_JMP32 | BPF_JLE | BPF_K: + case BPF_JMP | BPF_JNE | BPF_K: + case BPF_JMP32 | BPF_JNE | BPF_K: + case BPF_JMP | BPF_JSGT | BPF_K: + case BPF_JMP32 | BPF_JSGT | BPF_K: + case BPF_JMP | BPF_JSLT | BPF_K: + case BPF_JMP32 | BPF_JSLT | BPF_K: + case BPF_JMP | BPF_JSGE | BPF_K: + case BPF_JMP32 | BPF_JSGE | BPF_K: + case BPF_JMP | BPF_JSLE | BPF_K: + case BPF_JMP32 | BPF_JSLE | BPF_K: + rvoff = rv_offset(i, off, ctx); + s = ctx->ninsns; + if (imm) { + emit_imm(RV_REG_T1, imm, ctx); + rs = RV_REG_T1; + } else { + /* If imm is 0, simply use zero register. */ + rs = RV_REG_ZERO; + } + if (!is64) { + if (is_signed_bpf_cond(BPF_OP(code))) + emit_sext_32_rd(&rd, ctx); + else + emit_zext_32_rd_t1(&rd, ctx); + } + e = ctx->ninsns; + + /* Adjust for extra insns */ + rvoff -= ninsns_rvoff(e - s); + emit_branch(BPF_OP(code), rd, rs, rvoff, ctx); + break; + + case BPF_JMP | BPF_JSET | BPF_K: + case BPF_JMP32 | BPF_JSET | BPF_K: + rvoff = rv_offset(i, off, ctx); + s = ctx->ninsns; + if (is_12b_int(imm)) { + emit_andi(RV_REG_T1, rd, imm, ctx); + } else { + emit_imm(RV_REG_T1, imm, ctx); + emit_and(RV_REG_T1, rd, RV_REG_T1, ctx); + } + /* For jset32, we should clear the upper 32 bits of t1, but + * sign-extension is sufficient here and saves one instruction, + * as t1 is used only in comparison against zero. + */ + if (!is64 && imm < 0) + emit_addiw(RV_REG_T1, RV_REG_T1, 0, ctx); + e = ctx->ninsns; + rvoff -= ninsns_rvoff(e - s); + emit_branch(BPF_JNE, RV_REG_T1, RV_REG_ZERO, rvoff, ctx); + break; + + /* function call */ + case BPF_JMP | BPF_CALL: + { + bool fixed_addr; + u64 addr; + + mark_call(ctx); + ret = bpf_jit_get_func_addr(ctx->prog, insn, extra_pass, + &addr, &fixed_addr); + if (ret < 0) + return ret; + + ret = emit_call(addr, fixed_addr, ctx); + if (ret) + return ret; + + if (insn->src_reg != BPF_PSEUDO_CALL) + emit_mv(bpf_to_rv_reg(BPF_REG_0, ctx), RV_REG_A0, ctx); + break; + } + /* tail call */ + case BPF_JMP | BPF_TAIL_CALL: + if (emit_bpf_tail_call(i, ctx)) + return -1; + break; + + /* function return */ + case BPF_JMP | BPF_EXIT: + if (i == ctx->prog->len - 1) + break; + + rvoff = epilogue_offset(ctx); + ret = emit_jump_and_link(RV_REG_ZERO, rvoff, true, ctx); + if (ret) + return ret; + break; + + /* dst = imm64 */ + case BPF_LD | BPF_IMM | BPF_DW: + { + struct bpf_insn insn1 = insn[1]; + u64 imm64; + + imm64 = (u64)insn1.imm << 32 | (u32)imm; + if (bpf_pseudo_func(insn)) { + /* fixed-length insns for extra jit pass */ + ret = emit_addr(rd, imm64, extra_pass, ctx); + if (ret) + return ret; + } else { + emit_imm(rd, imm64, ctx); + } + + return 1; + } + + /* LDX: dst = *(size *)(src + off) */ + case BPF_LDX | BPF_MEM | BPF_B: + case BPF_LDX | BPF_MEM | BPF_H: + case BPF_LDX | BPF_MEM | BPF_W: + case BPF_LDX | BPF_MEM | BPF_DW: + case BPF_LDX | BPF_PROBE_MEM | BPF_B: + case BPF_LDX | BPF_PROBE_MEM | BPF_H: + case BPF_LDX | BPF_PROBE_MEM | BPF_W: + case BPF_LDX | BPF_PROBE_MEM | BPF_DW: + { + int insn_len, insns_start; + + switch (BPF_SIZE(code)) { + case BPF_B: + if (is_12b_int(off)) { + insns_start = ctx->ninsns; + 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; + emit(rv_lbu(rd, 0, RV_REG_T1), ctx); + insn_len = ctx->ninsns - insns_start; + if (insn_is_zext(&insn[1])) + return 1; + break; + case BPF_H: + if (is_12b_int(off)) { + insns_start = ctx->ninsns; + 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; + emit(rv_lhu(rd, 0, RV_REG_T1), ctx); + insn_len = ctx->ninsns - insns_start; + if (insn_is_zext(&insn[1])) + return 1; + break; + case BPF_W: + if (is_12b_int(off)) { + insns_start = ctx->ninsns; + 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; + emit(rv_lwu(rd, 0, RV_REG_T1), ctx); + insn_len = ctx->ninsns - insns_start; + if (insn_is_zext(&insn[1])) + return 1; + 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; + break; + } + + ret = add_exception_handler(insn, ctx, rd, insn_len); + if (ret) + return ret; + break; + } + /* speculation barrier */ + case BPF_ST | BPF_NOSPEC: + break; + + /* ST: *(size *)(dst + off) = imm */ + case BPF_ST | BPF_MEM | BPF_B: + emit_imm(RV_REG_T1, imm, ctx); + if (is_12b_int(off)) { + emit(rv_sb(rd, off, RV_REG_T1), ctx); + break; + } + + emit_imm(RV_REG_T2, off, ctx); + emit_add(RV_REG_T2, RV_REG_T2, rd, ctx); + emit(rv_sb(RV_REG_T2, 0, RV_REG_T1), ctx); + break; + + case BPF_ST | BPF_MEM | BPF_H: + emit_imm(RV_REG_T1, imm, ctx); + if (is_12b_int(off)) { + emit(rv_sh(rd, off, RV_REG_T1), ctx); + break; + } + + emit_imm(RV_REG_T2, off, ctx); + emit_add(RV_REG_T2, RV_REG_T2, rd, ctx); + emit(rv_sh(RV_REG_T2, 0, RV_REG_T1), ctx); + break; + case BPF_ST | BPF_MEM | BPF_W: + emit_imm(RV_REG_T1, imm, ctx); + if (is_12b_int(off)) { + emit_sw(rd, off, RV_REG_T1, ctx); + break; + } + + emit_imm(RV_REG_T2, off, ctx); + emit_add(RV_REG_T2, RV_REG_T2, rd, ctx); + emit_sw(RV_REG_T2, 0, RV_REG_T1, ctx); + break; + case BPF_ST | BPF_MEM | BPF_DW: + emit_imm(RV_REG_T1, imm, ctx); + if (is_12b_int(off)) { + emit_sd(rd, off, RV_REG_T1, ctx); + break; + } + + emit_imm(RV_REG_T2, off, ctx); + emit_add(RV_REG_T2, RV_REG_T2, rd, ctx); + emit_sd(RV_REG_T2, 0, RV_REG_T1, ctx); + break; + + /* 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); + 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); + 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); + 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); + break; + case BPF_STX | BPF_ATOMIC | BPF_W: + case BPF_STX | BPF_ATOMIC | BPF_DW: + emit_atomic(rd, rs, off, imm, + BPF_SIZE(code) == BPF_DW, ctx); + break; + default: + pr_err("bpf-jit: unknown opcode %02x\n", code); + return -EINVAL; + } + + return 0; +} + +void bpf_jit_build_prologue(struct rv_jit_context *ctx) +{ + int stack_adjust = 0, store_offset, bpf_stack_adjust; + + bpf_stack_adjust = round_up(ctx->prog->aux->stack_depth, 16); + if (bpf_stack_adjust) + mark_fp(ctx); + + if (seen_reg(RV_REG_RA, ctx)) + stack_adjust += 8; + stack_adjust += 8; /* RV_REG_FP */ + if (seen_reg(RV_REG_S1, ctx)) + stack_adjust += 8; + if (seen_reg(RV_REG_S2, ctx)) + stack_adjust += 8; + if (seen_reg(RV_REG_S3, ctx)) + stack_adjust += 8; + if (seen_reg(RV_REG_S4, ctx)) + stack_adjust += 8; + if (seen_reg(RV_REG_S5, ctx)) + stack_adjust += 8; + if (seen_reg(RV_REG_S6, ctx)) + stack_adjust += 8; + + stack_adjust = round_up(stack_adjust, 16); + stack_adjust += bpf_stack_adjust; + + store_offset = stack_adjust - 8; + + /* First instruction is always setting the tail-call-counter + * (TCC) register. This instruction is skipped for tail calls. + * Force using a 4-byte (non-compressed) instruction. + */ + emit(rv_addi(RV_REG_TCC, RV_REG_ZERO, MAX_TAIL_CALL_CNT), ctx); + + emit_addi(RV_REG_SP, RV_REG_SP, -stack_adjust, ctx); + + if (seen_reg(RV_REG_RA, ctx)) { + emit_sd(RV_REG_SP, store_offset, RV_REG_RA, ctx); + store_offset -= 8; + } + emit_sd(RV_REG_SP, store_offset, RV_REG_FP, ctx); + store_offset -= 8; + if (seen_reg(RV_REG_S1, ctx)) { + emit_sd(RV_REG_SP, store_offset, RV_REG_S1, ctx); + store_offset -= 8; + } + if (seen_reg(RV_REG_S2, ctx)) { + emit_sd(RV_REG_SP, store_offset, RV_REG_S2, ctx); + store_offset -= 8; + } + if (seen_reg(RV_REG_S3, ctx)) { + emit_sd(RV_REG_SP, store_offset, RV_REG_S3, ctx); + store_offset -= 8; + } + if (seen_reg(RV_REG_S4, ctx)) { + emit_sd(RV_REG_SP, store_offset, RV_REG_S4, ctx); + store_offset -= 8; + } + if (seen_reg(RV_REG_S5, ctx)) { + emit_sd(RV_REG_SP, store_offset, RV_REG_S5, ctx); + store_offset -= 8; + } + if (seen_reg(RV_REG_S6, ctx)) { + emit_sd(RV_REG_SP, store_offset, RV_REG_S6, ctx); + store_offset -= 8; + } + + emit_addi(RV_REG_FP, RV_REG_SP, stack_adjust, ctx); + + if (bpf_stack_adjust) + emit_addi(RV_REG_S5, RV_REG_SP, bpf_stack_adjust, ctx); + + /* Program contains calls and tail calls, so RV_REG_TCC need + * to be saved across calls. + */ + if (seen_tail_call(ctx) && seen_call(ctx)) + emit_mv(RV_REG_TCC_SAVED, RV_REG_TCC, ctx); + + ctx->stack_size = stack_adjust; +} + +void bpf_jit_build_epilogue(struct rv_jit_context *ctx) +{ + __build_epilogue(false, ctx); +} diff --git a/arch/riscv/net/bpf_jit_core.c b/arch/riscv/net/bpf_jit_core.c new file mode 100644 index 000000000..7a26a3e1c --- /dev/null +++ b/arch/riscv/net/bpf_jit_core.c @@ -0,0 +1,206 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Common functionality for RV32 and RV64 BPF JIT compilers + * + * Copyright (c) 2019 Björn Töpel <bjorn.topel@gmail.com> + * + */ + +#include <linux/bpf.h> +#include <linux/filter.h> +#include "bpf_jit.h" + +/* Number of iterations to try until offsets converge. */ +#define NR_JIT_ITERATIONS 32 + +static int build_body(struct rv_jit_context *ctx, bool extra_pass, int *offset) +{ + const struct bpf_prog *prog = ctx->prog; + int i; + + for (i = 0; i < prog->len; i++) { + const struct bpf_insn *insn = &prog->insnsi[i]; + int ret; + + ret = bpf_jit_emit_insn(insn, ctx, extra_pass); + /* BPF_LD | BPF_IMM | BPF_DW: skip the next instruction. */ + if (ret > 0) + i++; + if (offset) + offset[i] = ctx->ninsns; + if (ret < 0) + return ret; + } + return 0; +} + +bool bpf_jit_needs_zext(void) +{ + return true; +} + +struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) +{ + unsigned int prog_size = 0, extable_size = 0; + bool tmp_blinded = false, extra_pass = false; + struct bpf_prog *tmp, *orig_prog = prog; + int pass = 0, prev_ninsns = 0, i; + struct rv_jit_data *jit_data; + struct rv_jit_context *ctx; + + if (!prog->jit_requested) + return orig_prog; + + tmp = bpf_jit_blind_constants(prog); + if (IS_ERR(tmp)) + return orig_prog; + if (tmp != prog) { + tmp_blinded = true; + prog = tmp; + } + + jit_data = prog->aux->jit_data; + if (!jit_data) { + jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL); + if (!jit_data) { + prog = orig_prog; + goto out; + } + prog->aux->jit_data = jit_data; + } + + ctx = &jit_data->ctx; + + if (ctx->offset) { + extra_pass = true; + prog_size = sizeof(*ctx->insns) * ctx->ninsns; + goto skip_init_ctx; + } + + ctx->prog = prog; + ctx->offset = kcalloc(prog->len, sizeof(int), GFP_KERNEL); + if (!ctx->offset) { + prog = orig_prog; + goto out_offset; + } + + if (build_body(ctx, extra_pass, NULL)) { + prog = orig_prog; + goto out_offset; + } + + for (i = 0; i < prog->len; i++) { + prev_ninsns += 32; + ctx->offset[i] = prev_ninsns; + } + + for (i = 0; i < NR_JIT_ITERATIONS; i++) { + pass++; + ctx->ninsns = 0; + + bpf_jit_build_prologue(ctx); + ctx->prologue_len = ctx->ninsns; + + if (build_body(ctx, extra_pass, ctx->offset)) { + prog = orig_prog; + goto out_offset; + } + + ctx->epilogue_offset = ctx->ninsns; + bpf_jit_build_epilogue(ctx); + + if (ctx->ninsns == prev_ninsns) { + if (jit_data->header) + break; + /* obtain the actual image size */ + extable_size = prog->aux->num_exentries * + sizeof(struct exception_table_entry); + prog_size = sizeof(*ctx->insns) * ctx->ninsns; + + jit_data->header = + bpf_jit_binary_alloc(prog_size + extable_size, + &jit_data->image, + sizeof(u32), + bpf_fill_ill_insns); + if (!jit_data->header) { + prog = orig_prog; + goto out_offset; + } + + ctx->insns = (u16 *)jit_data->image; + /* + * Now, when the image is allocated, the image can + * potentially shrink more (auipc/jalr -> jal). + */ + } + prev_ninsns = ctx->ninsns; + } + + if (i == NR_JIT_ITERATIONS) { + pr_err("bpf-jit: image did not converge in <%d passes!\n", i); + if (jit_data->header) + bpf_jit_binary_free(jit_data->header); + prog = orig_prog; + goto out_offset; + } + + if (extable_size) + prog->aux->extable = (void *)ctx->insns + prog_size; + +skip_init_ctx: + pass++; + ctx->ninsns = 0; + ctx->nexentries = 0; + + bpf_jit_build_prologue(ctx); + if (build_body(ctx, extra_pass, NULL)) { + bpf_jit_binary_free(jit_data->header); + prog = orig_prog; + goto out_offset; + } + bpf_jit_build_epilogue(ctx); + + if (bpf_jit_enable > 1) + bpf_jit_dump(prog->len, prog_size, pass, ctx->insns); + + prog->bpf_func = (void *)ctx->insns; + prog->jited = 1; + prog->jited_len = prog_size; + + bpf_flush_icache(jit_data->header, ctx->insns + ctx->ninsns); + + if (!prog->is_func || extra_pass) { + bpf_jit_binary_lock_ro(jit_data->header); + for (i = 0; i < prog->len; i++) + ctx->offset[i] = ninsns_rvoff(ctx->offset[i]); + bpf_prog_fill_jited_linfo(prog, ctx->offset); +out_offset: + kfree(ctx->offset); + kfree(jit_data); + prog->aux->jit_data = NULL; + } +out: + + if (tmp_blinded) + bpf_jit_prog_release_other(prog, prog == orig_prog ? + tmp : orig_prog); + return prog; +} + +u64 bpf_jit_alloc_exec_limit(void) +{ + return BPF_JIT_REGION_SIZE; +} + +void *bpf_jit_alloc_exec(unsigned long size) +{ + return __vmalloc_node_range(size, PAGE_SIZE, BPF_JIT_REGION_START, + BPF_JIT_REGION_END, GFP_KERNEL, + PAGE_KERNEL, 0, NUMA_NO_NODE, + __builtin_return_address(0)); +} + +void bpf_jit_free_exec(void *addr) +{ + return vfree(addr); +} |