aboutsummaryrefslogtreecommitdiffstats
path: root/arch/riscv/net/bpf_jit_comp.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/riscv/net/bpf_jit_comp.c')
-rw-r--r--arch/riscv/net/bpf_jit_comp.c1602
1 files changed, 1602 insertions, 0 deletions
diff --git a/arch/riscv/net/bpf_jit_comp.c b/arch/riscv/net/bpf_jit_comp.c
new file mode 100644
index 000000000000..80b12aa5e10d
--- /dev/null
+++ b/arch/riscv/net/bpf_jit_comp.c
@@ -0,0 +1,1602 @@
+// SPDX-License-Identifier: GPL-2.0
+/* BPF JIT compiler for RV64G
+ *
+ * Copyright(c) 2019 Björn Töpel <bjorn.topel@gmail.com>
+ *
+ */
+
+#include <linux/bpf.h>
+#include <linux/filter.h>
+#include <asm/cacheflush.h>
+
+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,
+ RV_REG_S1 = 9, /* Saved registers */
+ 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,
+};
+
+#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,
+};
+
+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,
+};
+
+struct rv_jit_context {
+ struct bpf_prog *prog;
+ u32 *insns; /* RV insns */
+ int ninsns;
+ int epilogue_offset;
+ int *offset; /* BPF to RV */
+ unsigned long flags;
+ int stack_size;
+};
+
+struct rv_jit_data {
+ struct bpf_binary_header *header;
+ u8 *image;
+ struct rv_jit_context ctx;
+};
+
+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_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 void emit(const u32 insn, struct rv_jit_context *ctx)
+{
+ if (ctx->insns)
+ ctx->insns[ctx->ninsns] = insn;
+
+ ctx->ninsns++;
+}
+
+static 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 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 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 u32 rv_sb_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 u32 rv_u_insn(u32 imm31_12, u8 rd, u8 opcode)
+{
+ return (imm31_12 << 12) | (rd << 7) | opcode;
+}
+
+static u32 rv_uj_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 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);
+}
+
+static u32 rv_addiw(u8 rd, u8 rs1, u16 imm11_0)
+{
+ return rv_i_insn(imm11_0, rs1, 0, rd, 0x1b);
+}
+
+static u32 rv_addi(u8 rd, u8 rs1, u16 imm11_0)
+{
+ return rv_i_insn(imm11_0, rs1, 0, rd, 0x13);
+}
+
+static u32 rv_addw(u8 rd, u8 rs1, u8 rs2)
+{
+ return rv_r_insn(0, rs2, rs1, 0, rd, 0x3b);
+}
+
+static u32 rv_add(u8 rd, u8 rs1, u8 rs2)
+{
+ return rv_r_insn(0, rs2, rs1, 0, rd, 0x33);
+}
+
+static u32 rv_subw(u8 rd, u8 rs1, u8 rs2)
+{
+ return rv_r_insn(0x20, rs2, rs1, 0, rd, 0x3b);
+}
+
+static u32 rv_sub(u8 rd, u8 rs1, u8 rs2)
+{
+ return rv_r_insn(0x20, rs2, rs1, 0, rd, 0x33);
+}
+
+static u32 rv_and(u8 rd, u8 rs1, u8 rs2)
+{
+ return rv_r_insn(0, rs2, rs1, 7, rd, 0x33);
+}
+
+static u32 rv_or(u8 rd, u8 rs1, u8 rs2)
+{
+ return rv_r_insn(0, rs2, rs1, 6, rd, 0x33);
+}
+
+static u32 rv_xor(u8 rd, u8 rs1, u8 rs2)
+{
+ return rv_r_insn(0, rs2, rs1, 4, rd, 0x33);
+}
+
+static u32 rv_mulw(u8 rd, u8 rs1, u8 rs2)
+{
+ return rv_r_insn(1, rs2, rs1, 0, rd, 0x3b);
+}
+
+static u32 rv_mul(u8 rd, u8 rs1, u8 rs2)
+{
+ return rv_r_insn(1, rs2, rs1, 0, rd, 0x33);
+}
+
+static u32 rv_divuw(u8 rd, u8 rs1, u8 rs2)
+{
+ return rv_r_insn(1, rs2, rs1, 5, rd, 0x3b);
+}
+
+static u32 rv_divu(u8 rd, u8 rs1, u8 rs2)
+{
+ return rv_r_insn(1, rs2, rs1, 5, rd, 0x33);
+}
+
+static u32 rv_remuw(u8 rd, u8 rs1, u8 rs2)
+{
+ return rv_r_insn(1, rs2, rs1, 7, rd, 0x3b);
+}
+
+static u32 rv_remu(u8 rd, u8 rs1, u8 rs2)
+{
+ return rv_r_insn(1, rs2, rs1, 7, rd, 0x33);
+}
+
+static u32 rv_sllw(u8 rd, u8 rs1, u8 rs2)
+{
+ return rv_r_insn(0, rs2, rs1, 1, rd, 0x3b);
+}
+
+static u32 rv_sll(u8 rd, u8 rs1, u8 rs2)
+{
+ return rv_r_insn(0, rs2, rs1, 1, rd, 0x33);
+}
+
+static u32 rv_srlw(u8 rd, u8 rs1, u8 rs2)
+{
+ return rv_r_insn(0, rs2, rs1, 5, rd, 0x3b);
+}
+
+static u32 rv_srl(u8 rd, u8 rs1, u8 rs2)
+{
+ return rv_r_insn(0, rs2, rs1, 5, rd, 0x33);
+}
+
+static u32 rv_sraw(u8 rd, u8 rs1, u8 rs2)
+{
+ return rv_r_insn(0x20, rs2, rs1, 5, rd, 0x3b);
+}
+
+static u32 rv_sra(u8 rd, u8 rs1, u8 rs2)
+{
+ return rv_r_insn(0x20, rs2, rs1, 5, rd, 0x33);
+}
+
+static u32 rv_lui(u8 rd, u32 imm31_12)
+{
+ return rv_u_insn(imm31_12, rd, 0x37);
+}
+
+static u32 rv_slli(u8 rd, u8 rs1, u16 imm11_0)
+{
+ return rv_i_insn(imm11_0, rs1, 1, rd, 0x13);
+}
+
+static u32 rv_andi(u8 rd, u8 rs1, u16 imm11_0)
+{
+ return rv_i_insn(imm11_0, rs1, 7, rd, 0x13);
+}
+
+static u32 rv_ori(u8 rd, u8 rs1, u16 imm11_0)
+{
+ return rv_i_insn(imm11_0, rs1, 6, rd, 0x13);
+}
+
+static u32 rv_xori(u8 rd, u8 rs1, u16 imm11_0)
+{
+ return rv_i_insn(imm11_0, rs1, 4, rd, 0x13);
+}
+
+static u32 rv_slliw(u8 rd, u8 rs1, u16 imm11_0)
+{
+ return rv_i_insn(imm11_0, rs1, 1, rd, 0x1b);
+}
+
+static u32 rv_srliw(u8 rd, u8 rs1, u16 imm11_0)
+{
+ return rv_i_insn(imm11_0, rs1, 5, rd, 0x1b);
+}
+
+static u32 rv_srli(u8 rd, u8 rs1, u16 imm11_0)
+{
+ return rv_i_insn(imm11_0, rs1, 5, rd, 0x13);
+}
+
+static u32 rv_sraiw(u8 rd, u8 rs1, u16 imm11_0)
+{
+ return rv_i_insn(0x400 | imm11_0, rs1, 5, rd, 0x1b);
+}
+
+static u32 rv_srai(u8 rd, u8 rs1, u16 imm11_0)
+{
+ return rv_i_insn(0x400 | imm11_0, rs1, 5, rd, 0x13);
+}
+
+static u32 rv_jal(u8 rd, u32 imm20_1)
+{
+ return rv_uj_insn(imm20_1, rd, 0x6f);
+}
+
+static u32 rv_jalr(u8 rd, u8 rs1, u16 imm11_0)
+{
+ return rv_i_insn(imm11_0, rs1, 0, rd, 0x67);
+}
+
+static u32 rv_beq(u8 rs1, u8 rs2, u16 imm12_1)
+{
+ return rv_sb_insn(imm12_1, rs2, rs1, 0, 0x63);
+}
+
+static u32 rv_bltu(u8 rs1, u8 rs2, u16 imm12_1)
+{
+ return rv_sb_insn(imm12_1, rs2, rs1, 6, 0x63);
+}
+
+static u32 rv_bgeu(u8 rs1, u8 rs2, u16 imm12_1)
+{
+ return rv_sb_insn(imm12_1, rs2, rs1, 7, 0x63);
+}
+
+static u32 rv_bne(u8 rs1, u8 rs2, u16 imm12_1)
+{
+ return rv_sb_insn(imm12_1, rs2, rs1, 1, 0x63);
+}
+
+static u32 rv_blt(u8 rs1, u8 rs2, u16 imm12_1)
+{
+ return rv_sb_insn(imm12_1, rs2, rs1, 4, 0x63);
+}
+
+static u32 rv_bge(u8 rs1, u8 rs2, u16 imm12_1)
+{
+ return rv_sb_insn(imm12_1, rs2, rs1, 5, 0x63);
+}
+
+static u32 rv_sb(u8 rs1, u16 imm11_0, u8 rs2)
+{
+ return rv_s_insn(imm11_0, rs2, rs1, 0, 0x23);
+}
+
+static u32 rv_sh(u8 rs1, u16 imm11_0, u8 rs2)
+{
+ return rv_s_insn(imm11_0, rs2, rs1, 1, 0x23);
+}
+
+static u32 rv_sw(u8 rs1, u16 imm11_0, u8 rs2)
+{
+ return rv_s_insn(imm11_0, rs2, rs1, 2, 0x23);
+}
+
+static u32 rv_sd(u8 rs1, u16 imm11_0, u8 rs2)
+{
+ return rv_s_insn(imm11_0, rs2, rs1, 3, 0x23);
+}
+
+static u32 rv_lbu(u8 rd, u16 imm11_0, u8 rs1)
+{
+ return rv_i_insn(imm11_0, rs1, 4, rd, 0x03);
+}
+
+static u32 rv_lhu(u8 rd, u16 imm11_0, u8 rs1)
+{
+ return rv_i_insn(imm11_0, rs1, 5, rd, 0x03);
+}
+
+static u32 rv_lwu(u8 rd, u16 imm11_0, u8 rs1)
+{
+ return rv_i_insn(imm11_0, rs1, 6, rd, 0x03);
+}
+
+static u32 rv_ld(u8 rd, u16 imm11_0, u8 rs1)
+{
+ return rv_i_insn(imm11_0, rs1, 3, rd, 0x03);
+}
+
+static 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 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 bool is_12b_int(s64 val)
+{
+ return -(1 << 11) <= val && val < (1 << 11);
+}
+
+static bool is_13b_int(s64 val)
+{
+ return -(1 << 12) <= val && val < (1 << 12);
+}
+
+static bool is_21b_int(s64 val)
+{
+ return -(1L << 20) <= val && val < (1L << 20);
+}
+
+static bool is_32b_int(s64 val)
+{
+ return -(1L << 31) <= val && val < (1L << 31);
+}
+
+static int is_12b_check(int off, int insn)
+{
+ if (!is_12b_int(off)) {
+ pr_err("bpf-jit: insn=%d offset=%d not supported yet!\n",
+ insn, (int)off);
+ return -1;
+ }
+ return 0;
+}
+
+static int is_13b_check(int off, int insn)
+{
+ if (!is_13b_int(off)) {
+ pr_err("bpf-jit: insn=%d offset=%d not supported yet!\n",
+ insn, (int)off);
+ return -1;
+ }
+ return 0;
+}
+
+static int is_21b_check(int off, int insn)
+{
+ if (!is_21b_int(off)) {
+ pr_err("bpf-jit: insn=%d offset=%d not supported yet!\n",
+ insn, (int)off);
+ return -1;
+ }
+ return 0;
+}
+
+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, lower = val & 0xfff;
+ int shift;
+
+ if (is_32b_int(val)) {
+ if (upper)
+ emit(rv_lui(rd, upper), ctx);
+
+ if (!upper) {
+ emit(rv_addi(rd, RV_REG_ZERO, lower), ctx);
+ return;
+ }
+
+ emit(rv_addiw(rd, rd, lower), ctx);
+ return;
+ }
+
+ shift = __ffs(upper);
+ upper >>= shift;
+ shift += 12;
+
+ emit_imm(rd, upper, ctx);
+
+ emit(rv_slli(rd, rd, shift), ctx);
+ if (lower)
+ emit(rv_addi(rd, rd, lower), ctx);
+}
+
+static int rv_offset(int bpf_to, int bpf_from, struct rv_jit_context *ctx)
+{
+ int from = ctx->offset[bpf_from] - 1, to = ctx->offset[bpf_to];
+
+ return (to - from) << 2;
+}
+
+static int epilogue_offset(struct rv_jit_context *ctx)
+{
+ int to = ctx->epilogue_offset, from = ctx->ninsns;
+
+ return (to - from) << 2;
+}
+
+static void __build_epilogue(u8 reg, struct rv_jit_context *ctx)
+{
+ int stack_adjust = ctx->stack_size, store_offset = stack_adjust - 8;
+
+ if (seen_reg(RV_REG_RA, ctx)) {
+ emit(rv_ld(RV_REG_RA, store_offset, RV_REG_SP), ctx);
+ store_offset -= 8;
+ }
+ emit(rv_ld(RV_REG_FP, store_offset, RV_REG_SP), ctx);
+ store_offset -= 8;
+ if (seen_reg(RV_REG_S1, ctx)) {
+ emit(rv_ld(RV_REG_S1, store_offset, RV_REG_SP), ctx);
+ store_offset -= 8;
+ }
+ if (seen_reg(RV_REG_S2, ctx)) {
+ emit(rv_ld(RV_REG_S2, store_offset, RV_REG_SP), ctx);
+ store_offset -= 8;
+ }
+ if (seen_reg(RV_REG_S3, ctx)) {
+ emit(rv_ld(RV_REG_S3, store_offset, RV_REG_SP), ctx);
+ store_offset -= 8;
+ }
+ if (seen_reg(RV_REG_S4, ctx)) {
+ emit(rv_ld(RV_REG_S4, store_offset, RV_REG_SP), ctx);
+ store_offset -= 8;
+ }
+ if (seen_reg(RV_REG_S5, ctx)) {
+ emit(rv_ld(RV_REG_S5, store_offset, RV_REG_SP), ctx);
+ store_offset -= 8;
+ }
+ if (seen_reg(RV_REG_S6, ctx)) {
+ emit(rv_ld(RV_REG_S6, store_offset, RV_REG_SP), ctx);
+ store_offset -= 8;
+ }
+
+ emit(rv_addi(RV_REG_SP, RV_REG_SP, stack_adjust), ctx);
+ /* Set return value. */
+ emit(rv_addi(RV_REG_A0, RV_REG_A5, 0), ctx);
+ emit(rv_jalr(RV_REG_ZERO, reg, 0), ctx);
+}
+
+static void emit_zext_32(u8 reg, struct rv_jit_context *ctx)
+{
+ emit(rv_slli(reg, reg, 32), ctx);
+ emit(rv_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 = (tc_ninsn - (ctx->ninsns - start_insn)) << 2;
+ if (is_13b_check(off, insn))
+ return -1;
+ emit(rv_bgeu(RV_REG_A2, RV_REG_T1, off >> 1), ctx);
+
+ /* if (--TCC < 0)
+ * goto out;
+ */
+ emit(rv_addi(RV_REG_T1, tcc, -1), ctx);
+ off = (tc_ninsn - (ctx->ninsns - start_insn)) << 2;
+ if (is_13b_check(off, insn))
+ return -1;
+ emit(rv_blt(RV_REG_T1, RV_REG_ZERO, off >> 1), ctx);
+
+ /* prog = array->ptrs[index];
+ * if (!prog)
+ * goto out;
+ */
+ emit(rv_slli(RV_REG_T2, RV_REG_A2, 3), ctx);
+ emit(rv_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(rv_ld(RV_REG_T2, off, RV_REG_T2), ctx);
+ off = (tc_ninsn - (ctx->ninsns - start_insn)) << 2;
+ if (is_13b_check(off, insn))
+ return -1;
+ emit(rv_beq(RV_REG_T2, RV_REG_ZERO, off >> 1), ctx);
+
+ /* goto *(prog->bpf_func + 4); */
+ off = offsetof(struct bpf_prog, bpf_func);
+ if (is_12b_check(off, insn))
+ return -1;
+ emit(rv_ld(RV_REG_T3, off, RV_REG_T2), ctx);
+ emit(rv_addi(RV_REG_T3, RV_REG_T3, 4), ctx);
+ emit(rv_addi(RV_REG_TCC, RV_REG_T1, 0), ctx);
+ __build_epilogue(RV_REG_T3, 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 int rv_offset_check(int *rvoff, s16 off, int insn,
+ struct rv_jit_context *ctx)
+{
+ *rvoff = rv_offset(insn + off, insn, ctx);
+ return is_13b_check(*rvoff, insn);
+}
+
+static void emit_zext_32_rd_rs(u8 *rd, u8 *rs, struct rv_jit_context *ctx)
+{
+ emit(rv_addi(RV_REG_T2, *rd, 0), ctx);
+ emit_zext_32(RV_REG_T2, ctx);
+ emit(rv_addi(RV_REG_T1, *rs, 0), 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(rv_addiw(RV_REG_T2, *rd, 0), ctx);
+ emit(rv_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(rv_addi(RV_REG_T2, *rd, 0), 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(rv_addiw(RV_REG_T2, *rd, 0), ctx);
+ *rd = RV_REG_T2;
+}
+
+static int 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 rvoff, i = insn - ctx->prog->insnsi;
+ 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:
+ emit(is64 ? rv_addi(rd, rs, 0) : rv_addiw(rd, rs, 0), ctx);
+ if (!is64)
+ 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(is64 ? rv_add(rd, rd, rs) : rv_addw(rd, rd, rs), ctx);
+ break;
+ case BPF_ALU | BPF_SUB | BPF_X:
+ case BPF_ALU64 | BPF_SUB | BPF_X:
+ emit(is64 ? rv_sub(rd, rd, rs) : rv_subw(rd, rd, rs), ctx);
+ break;
+ case BPF_ALU | BPF_AND | BPF_X:
+ case BPF_ALU64 | BPF_AND | BPF_X:
+ emit(rv_and(rd, rd, rs), ctx);
+ break;
+ case BPF_ALU | BPF_OR | BPF_X:
+ case BPF_ALU64 | BPF_OR | BPF_X:
+ emit(rv_or(rd, rd, rs), ctx);
+ break;
+ case BPF_ALU | BPF_XOR | BPF_X:
+ case BPF_ALU64 | BPF_XOR | BPF_X:
+ emit(rv_xor(rd, rd, rs), 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)
+ 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)
+ 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)
+ 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);
+ 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);
+ 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);
+ break;
+
+ /* dst = -dst */
+ case BPF_ALU | BPF_NEG:
+ case BPF_ALU64 | BPF_NEG:
+ emit(is64 ? rv_sub(rd, RV_REG_ZERO, rd) :
+ rv_subw(rd, RV_REG_ZERO, rd), ctx);
+ break;
+
+ /* dst = BSWAP##imm(dst) */
+ case BPF_ALU | BPF_END | BPF_FROM_LE:
+ {
+ int shift = 64 - imm;
+
+ emit(rv_slli(rd, rd, shift), ctx);
+ emit(rv_srli(rd, rd, shift), ctx);
+ break;
+ }
+ case BPF_ALU | BPF_END | BPF_FROM_BE:
+ emit(rv_addi(RV_REG_T2, RV_REG_ZERO, 0), ctx);
+
+ emit(rv_andi(RV_REG_T1, rd, 0xff), ctx);
+ emit(rv_add(RV_REG_T2, RV_REG_T2, RV_REG_T1), ctx);
+ emit(rv_slli(RV_REG_T2, RV_REG_T2, 8), ctx);
+ emit(rv_srli(rd, rd, 8), ctx);
+ if (imm == 16)
+ goto out_be;
+
+ emit(rv_andi(RV_REG_T1, rd, 0xff), ctx);
+ emit(rv_add(RV_REG_T2, RV_REG_T2, RV_REG_T1), ctx);
+ emit(rv_slli(RV_REG_T2, RV_REG_T2, 8), ctx);
+ emit(rv_srli(rd, rd, 8), ctx);
+
+ emit(rv_andi(RV_REG_T1, rd, 0xff), ctx);
+ emit(rv_add(RV_REG_T2, RV_REG_T2, RV_REG_T1), ctx);
+ emit(rv_slli(RV_REG_T2, RV_REG_T2, 8), ctx);
+ emit(rv_srli(rd, rd, 8), ctx);
+ if (imm == 32)
+ goto out_be;
+
+ emit(rv_andi(RV_REG_T1, rd, 0xff), ctx);
+ emit(rv_add(RV_REG_T2, RV_REG_T2, RV_REG_T1), ctx);
+ emit(rv_slli(RV_REG_T2, RV_REG_T2, 8), ctx);
+ emit(rv_srli(rd, rd, 8), ctx);
+
+ emit(rv_andi(RV_REG_T1, rd, 0xff), ctx);
+ emit(rv_add(RV_REG_T2, RV_REG_T2, RV_REG_T1), ctx);
+ emit(rv_slli(RV_REG_T2, RV_REG_T2, 8), ctx);
+ emit(rv_srli(rd, rd, 8), ctx);
+
+ emit(rv_andi(RV_REG_T1, rd, 0xff), ctx);
+ emit(rv_add(RV_REG_T2, RV_REG_T2, RV_REG_T1), ctx);
+ emit(rv_slli(RV_REG_T2, RV_REG_T2, 8), ctx);
+ emit(rv_srli(rd, rd, 8), ctx);
+
+ emit(rv_andi(RV_REG_T1, rd, 0xff), ctx);
+ emit(rv_add(RV_REG_T2, RV_REG_T2, RV_REG_T1), ctx);
+ emit(rv_slli(RV_REG_T2, RV_REG_T2, 8), ctx);
+ emit(rv_srli(rd, rd, 8), ctx);
+out_be:
+ emit(rv_andi(RV_REG_T1, rd, 0xff), ctx);
+ emit(rv_add(RV_REG_T2, RV_REG_T2, RV_REG_T1), ctx);
+
+ emit(rv_addi(rd, RV_REG_T2, 0), 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)
+ 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(is64 ? rv_addi(rd, rd, imm) :
+ rv_addiw(rd, rd, imm), ctx);
+ } else {
+ emit_imm(RV_REG_T1, imm, ctx);
+ emit(is64 ? rv_add(rd, rd, RV_REG_T1) :
+ rv_addw(rd, rd, RV_REG_T1), ctx);
+ }
+ if (!is64)
+ 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(is64 ? rv_addi(rd, rd, -imm) :
+ rv_addiw(rd, rd, -imm), ctx);
+ } else {
+ emit_imm(RV_REG_T1, imm, ctx);
+ emit(is64 ? rv_sub(rd, rd, RV_REG_T1) :
+ rv_subw(rd, rd, RV_REG_T1), ctx);
+ }
+ if (!is64)
+ 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(rv_andi(rd, rd, imm), ctx);
+ } else {
+ emit_imm(RV_REG_T1, imm, ctx);
+ emit(rv_and(rd, rd, RV_REG_T1), ctx);
+ }
+ if (!is64)
+ 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(rv_or(rd, rd, RV_REG_T1), ctx);
+ }
+ if (!is64)
+ 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(rv_xor(rd, rd, RV_REG_T1), ctx);
+ }
+ if (!is64)
+ 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)
+ 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)
+ 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)
+ emit_zext_32(rd, ctx);
+ break;
+ case BPF_ALU | BPF_LSH | BPF_K:
+ case BPF_ALU64 | BPF_LSH | BPF_K:
+ emit(is64 ? rv_slli(rd, rd, imm) : rv_slliw(rd, rd, imm), ctx);
+ break;
+ case BPF_ALU | BPF_RSH | BPF_K:
+ case BPF_ALU64 | BPF_RSH | BPF_K:
+ emit(is64 ? rv_srli(rd, rd, imm) : rv_srliw(rd, rd, imm), ctx);
+ break;
+ case BPF_ALU | BPF_ARSH | BPF_K:
+ case BPF_ALU64 | BPF_ARSH | BPF_K:
+ emit(is64 ? rv_srai(rd, rd, imm) : rv_sraiw(rd, rd, imm), ctx);
+ break;
+
+ /* JUMP off */
+ case BPF_JMP | BPF_JA:
+ rvoff = rv_offset(i + off, i, ctx);
+ if (!is_21b_int(rvoff)) {
+ pr_err("bpf-jit: insn=%d offset=%d not supported yet!\n",
+ i, rvoff);
+ return -1;
+ }
+
+ emit(rv_jal(RV_REG_ZERO, rvoff >> 1), ctx);
+ break;
+
+ /* IF (dst COND src) JUMP off */
+ case BPF_JMP | BPF_JEQ | BPF_X:
+ case BPF_JMP32 | BPF_JEQ | BPF_X:
+ if (rv_offset_check(&rvoff, off, i, ctx))
+ return -1;
+ if (!is64)
+ emit_zext_32_rd_rs(&rd, &rs, ctx);
+ emit(rv_beq(rd, rs, rvoff >> 1), ctx);
+ break;
+ case BPF_JMP | BPF_JGT | BPF_X:
+ case BPF_JMP32 | BPF_JGT | BPF_X:
+ if (rv_offset_check(&rvoff, off, i, ctx))
+ return -1;
+ if (!is64)
+ emit_zext_32_rd_rs(&rd, &rs, ctx);
+ emit(rv_bltu(rs, rd, rvoff >> 1), ctx);
+ break;
+ case BPF_JMP | BPF_JLT | BPF_X:
+ case BPF_JMP32 | BPF_JLT | BPF_X:
+ if (rv_offset_check(&rvoff, off, i, ctx))
+ return -1;
+ if (!is64)
+ emit_zext_32_rd_rs(&rd, &rs, ctx);
+ emit(rv_bltu(rd, rs, rvoff >> 1), ctx);
+ break;
+ case BPF_JMP | BPF_JGE | BPF_X:
+ case BPF_JMP32 | BPF_JGE | BPF_X:
+ if (rv_offset_check(&rvoff, off, i, ctx))
+ return -1;
+ if (!is64)
+ emit_zext_32_rd_rs(&rd, &rs, ctx);
+ emit(rv_bgeu(rd, rs, rvoff >> 1), ctx);
+ break;
+ case BPF_JMP | BPF_JLE | BPF_X:
+ case BPF_JMP32 | BPF_JLE | BPF_X:
+ if (rv_offset_check(&rvoff, off, i, ctx))
+ return -1;
+ if (!is64)
+ emit_zext_32_rd_rs(&rd, &rs, ctx);
+ emit(rv_bgeu(rs, rd, rvoff >> 1), ctx);
+ break;
+ case BPF_JMP | BPF_JNE | BPF_X:
+ case BPF_JMP32 | BPF_JNE | BPF_X:
+ if (rv_offset_check(&rvoff, off, i, ctx))
+ return -1;
+ if (!is64)
+ emit_zext_32_rd_rs(&rd, &rs, ctx);
+ emit(rv_bne(rd, rs, rvoff >> 1), ctx);
+ break;
+ case BPF_JMP | BPF_JSGT | BPF_X:
+ case BPF_JMP32 | BPF_JSGT | BPF_X:
+ if (rv_offset_check(&rvoff, off, i, ctx))
+ return -1;
+ if (!is64)
+ emit_sext_32_rd_rs(&rd, &rs, ctx);
+ emit(rv_blt(rs, rd, rvoff >> 1), ctx);
+ break;
+ case BPF_JMP | BPF_JSLT | BPF_X:
+ case BPF_JMP32 | BPF_JSLT | BPF_X:
+ if (rv_offset_check(&rvoff, off, i, ctx))
+ return -1;
+ if (!is64)
+ emit_sext_32_rd_rs(&rd, &rs, ctx);
+ emit(rv_blt(rd, rs, rvoff >> 1), ctx);
+ break;
+ case BPF_JMP | BPF_JSGE | BPF_X:
+ case BPF_JMP32 | BPF_JSGE | BPF_X:
+ if (rv_offset_check(&rvoff, off, i, ctx))
+ return -1;
+ if (!is64)
+ emit_sext_32_rd_rs(&rd, &rs, ctx);
+ emit(rv_bge(rd, rs, rvoff >> 1), ctx);
+ break;
+ case BPF_JMP | BPF_JSLE | BPF_X:
+ case BPF_JMP32 | BPF_JSLE | BPF_X:
+ if (rv_offset_check(&rvoff, off, i, ctx))
+ return -1;
+ if (!is64)
+ emit_sext_32_rd_rs(&rd, &rs, ctx);
+ emit(rv_bge(rs, rd, rvoff >> 1), ctx);
+ break;
+ case BPF_JMP | BPF_JSET | BPF_X:
+ case BPF_JMP32 | BPF_JSET | BPF_X:
+ if (rv_offset_check(&rvoff, off, i, ctx))
+ return -1;
+ if (!is64)
+ emit_zext_32_rd_rs(&rd, &rs, ctx);
+ emit(rv_and(RV_REG_T1, rd, rs), ctx);
+ emit(rv_bne(RV_REG_T1, RV_REG_ZERO, rvoff >> 1), ctx);
+ break;
+
+ /* IF (dst COND imm) JUMP off */
+ case BPF_JMP | BPF_JEQ | BPF_K:
+ case BPF_JMP32 | BPF_JEQ | BPF_K:
+ if (rv_offset_check(&rvoff, off, i, ctx))
+ return -1;
+ emit_imm(RV_REG_T1, imm, ctx);
+ if (!is64)
+ emit_zext_32_rd_t1(&rd, ctx);
+ emit(rv_beq(rd, RV_REG_T1, rvoff >> 1), ctx);
+ break;
+ case BPF_JMP | BPF_JGT | BPF_K:
+ case BPF_JMP32 | BPF_JGT | BPF_K:
+ if (rv_offset_check(&rvoff, off, i, ctx))
+ return -1;
+ emit_imm(RV_REG_T1, imm, ctx);
+ if (!is64)
+ emit_zext_32_rd_t1(&rd, ctx);
+ emit(rv_bltu(RV_REG_T1, rd, rvoff >> 1), ctx);
+ break;
+ case BPF_JMP | BPF_JLT | BPF_K:
+ case BPF_JMP32 | BPF_JLT | BPF_K:
+ if (rv_offset_check(&rvoff, off, i, ctx))
+ return -1;
+ emit_imm(RV_REG_T1, imm, ctx);
+ if (!is64)
+ emit_zext_32_rd_t1(&rd, ctx);
+ emit(rv_bltu(rd, RV_REG_T1, rvoff >> 1), ctx);
+ break;
+ case BPF_JMP | BPF_JGE | BPF_K:
+ case BPF_JMP32 | BPF_JGE | BPF_K:
+ if (rv_offset_check(&rvoff, off, i, ctx))
+ return -1;
+ emit_imm(RV_REG_T1, imm, ctx);
+ if (!is64)
+ emit_zext_32_rd_t1(&rd, ctx);
+ emit(rv_bgeu(rd, RV_REG_T1, rvoff >> 1), ctx);
+ break;
+ case BPF_JMP | BPF_JLE | BPF_K:
+ case BPF_JMP32 | BPF_JLE | BPF_K:
+ if (rv_offset_check(&rvoff, off, i, ctx))
+ return -1;
+ emit_imm(RV_REG_T1, imm, ctx);
+ if (!is64)
+ emit_zext_32_rd_t1(&rd, ctx);
+ emit(rv_bgeu(RV_REG_T1, rd, rvoff >> 1), ctx);
+ break;
+ case BPF_JMP | BPF_JNE | BPF_K:
+ case BPF_JMP32 | BPF_JNE | BPF_K:
+ if (rv_offset_check(&rvoff, off, i, ctx))
+ return -1;
+ emit_imm(RV_REG_T1, imm, ctx);
+ if (!is64)
+ emit_zext_32_rd_t1(&rd, ctx);
+ emit(rv_bne(rd, RV_REG_T1, rvoff >> 1), ctx);
+ break;
+ case BPF_JMP | BPF_JSGT | BPF_K:
+ case BPF_JMP32 | BPF_JSGT | BPF_K:
+ if (rv_offset_check(&rvoff, off, i, ctx))
+ return -1;
+ emit_imm(RV_REG_T1, imm, ctx);
+ if (!is64)
+ emit_sext_32_rd(&rd, ctx);
+ emit(rv_blt(RV_REG_T1, rd, rvoff >> 1), ctx);
+ break;
+ case BPF_JMP | BPF_JSLT | BPF_K:
+ case BPF_JMP32 | BPF_JSLT | BPF_K:
+ if (rv_offset_check(&rvoff, off, i, ctx))
+ return -1;
+ emit_imm(RV_REG_T1, imm, ctx);
+ if (!is64)
+ emit_sext_32_rd(&rd, ctx);
+ emit(rv_blt(rd, RV_REG_T1, rvoff >> 1), ctx);
+ break;
+ case BPF_JMP | BPF_JSGE | BPF_K:
+ case BPF_JMP32 | BPF_JSGE | BPF_K:
+ if (rv_offset_check(&rvoff, off, i, ctx))
+ return -1;
+ emit_imm(RV_REG_T1, imm, ctx);
+ if (!is64)
+ emit_sext_32_rd(&rd, ctx);
+ emit(rv_bge(rd, RV_REG_T1, rvoff >> 1), ctx);
+ break;
+ case BPF_JMP | BPF_JSLE | BPF_K:
+ case BPF_JMP32 | BPF_JSLE | BPF_K:
+ if (rv_offset_check(&rvoff, off, i, ctx))
+ return -1;
+ emit_imm(RV_REG_T1, imm, ctx);
+ if (!is64)
+ emit_sext_32_rd(&rd, ctx);
+ emit(rv_bge(RV_REG_T1, rd, rvoff >> 1), ctx);
+ break;
+ case BPF_JMP | BPF_JSET | BPF_K:
+ case BPF_JMP32 | BPF_JSET | BPF_K:
+ if (rv_offset_check(&rvoff, off, i, ctx))
+ return -1;
+ emit_imm(RV_REG_T1, imm, ctx);
+ if (!is64)
+ emit_zext_32_rd_t1(&rd, ctx);
+ emit(rv_and(RV_REG_T1, rd, RV_REG_T1), ctx);
+ emit(rv_bne(RV_REG_T1, RV_REG_ZERO, rvoff >> 1), ctx);
+ break;
+
+ /* function call */
+ case BPF_JMP | BPF_CALL:
+ {
+ bool fixed;
+ int i, ret;
+ u64 addr;
+
+ mark_call(ctx);
+ ret = bpf_jit_get_func_addr(ctx->prog, insn, extra_pass, &addr,
+ &fixed);
+ if (ret < 0)
+ return ret;
+ if (fixed) {
+ emit_imm(RV_REG_T1, addr, ctx);
+ } else {
+ i = ctx->ninsns;
+ emit_imm(RV_REG_T1, addr, ctx);
+ for (i = ctx->ninsns - i; i < 8; i++) {
+ /* nop */
+ emit(rv_addi(RV_REG_ZERO, RV_REG_ZERO, 0),
+ ctx);
+ }
+ }
+ emit(rv_jalr(RV_REG_RA, RV_REG_T1, 0), ctx);
+ rd = bpf_to_rv_reg(BPF_REG_0, ctx);
+ emit(rv_addi(rd, RV_REG_A0, 0), 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);
+ if (is_21b_check(rvoff, i))
+ return -1;
+ emit(rv_jal(RV_REG_ZERO, rvoff >> 1), ctx);
+ 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;
+ emit_imm(rd, imm64, ctx);
+ return 1;
+ }
+
+ /* LDX: dst = *(size *)(src + off) */
+ case BPF_LDX | BPF_MEM | BPF_B:
+ if (is_12b_int(off)) {
+ emit(rv_lbu(rd, off, rs), ctx);
+ break;
+ }
+
+ emit_imm(RV_REG_T1, off, ctx);
+ emit(rv_add(RV_REG_T1, RV_REG_T1, rs), ctx);
+ emit(rv_lbu(rd, 0, RV_REG_T1), ctx);
+ break;
+ case BPF_LDX | BPF_MEM | BPF_H:
+ if (is_12b_int(off)) {
+ emit(rv_lhu(rd, off, rs), ctx);
+ break;
+ }
+
+ emit_imm(RV_REG_T1, off, ctx);
+ emit(rv_add(RV_REG_T1, RV_REG_T1, rs), ctx);
+ emit(rv_lhu(rd, 0, RV_REG_T1), ctx);
+ break;
+ case BPF_LDX | BPF_MEM | BPF_W:
+ if (is_12b_int(off)) {
+ emit(rv_lwu(rd, off, rs), ctx);
+ break;
+ }
+
+ emit_imm(RV_REG_T1, off, ctx);
+ emit(rv_add(RV_REG_T1, RV_REG_T1, rs), ctx);
+ emit(rv_lwu(rd, 0, RV_REG_T1), ctx);
+ break;
+ case BPF_LDX | BPF_MEM | BPF_DW:
+ if (is_12b_int(off)) {
+ emit(rv_ld(rd, off, rs), ctx);
+ break;
+ }
+
+ emit_imm(RV_REG_T1, off, ctx);
+ emit(rv_add(RV_REG_T1, RV_REG_T1, rs), ctx);
+ emit(rv_ld(rd, 0, RV_REG_T1), ctx);
+ 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(rv_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(rv_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(rv_sw(rd, off, RV_REG_T1), ctx);
+ break;
+ }
+
+ emit_imm(RV_REG_T2, off, ctx);
+ emit(rv_add(RV_REG_T2, RV_REG_T2, rd), ctx);
+ emit(rv_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(rv_sd(rd, off, RV_REG_T1), ctx);
+ break;
+ }
+
+ emit_imm(RV_REG_T2, off, ctx);
+ emit(rv_add(RV_REG_T2, RV_REG_T2, rd), ctx);
+ emit(rv_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(rv_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(rv_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(rv_sw(rd, off, rs), ctx);
+ break;
+ }
+
+ emit_imm(RV_REG_T1, off, ctx);
+ emit(rv_add(RV_REG_T1, RV_REG_T1, rd), ctx);
+ emit(rv_sw(RV_REG_T1, 0, rs), ctx);
+ break;
+ case BPF_STX | BPF_MEM | BPF_DW:
+ if (is_12b_int(off)) {
+ emit(rv_sd(rd, off, rs), ctx);
+ break;
+ }
+
+ emit_imm(RV_REG_T1, off, ctx);
+ emit(rv_add(RV_REG_T1, RV_REG_T1, rd), ctx);
+ emit(rv_sd(RV_REG_T1, 0, rs), ctx);
+ break;
+ /* STX XADD: lock *(u32 *)(dst + off) += src */
+ case BPF_STX | BPF_XADD | BPF_W:
+ /* STX XADD: lock *(u64 *)(dst + off) += src */
+ case BPF_STX | BPF_XADD | BPF_DW:
+ if (off) {
+ if (is_12b_int(off)) {
+ emit(rv_addi(RV_REG_T1, rd, off), ctx);
+ } else {
+ emit_imm(RV_REG_T1, off, ctx);
+ emit(rv_add(RV_REG_T1, RV_REG_T1, rd), ctx);
+ }
+
+ rd = RV_REG_T1;
+ }
+
+ emit(BPF_SIZE(code) == BPF_W ?
+ rv_amoadd_w(RV_REG_ZERO, rs, rd, 0, 0) :
+ rv_amoadd_d(RV_REG_ZERO, rs, rd, 0, 0), ctx);
+ break;
+ default:
+ pr_err("bpf-jit: unknown opcode %02x\n", code);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void build_prologue(struct rv_jit_context *ctx)
+{
+ int stack_adjust = 0, store_offset, bpf_stack_adjust;
+
+ 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);
+ bpf_stack_adjust = round_up(ctx->prog->aux->stack_depth, 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.
+ */
+ 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);
+
+ if (seen_reg(RV_REG_RA, ctx)) {
+ emit(rv_sd(RV_REG_SP, store_offset, RV_REG_RA), ctx);
+ store_offset -= 8;
+ }
+ emit(rv_sd(RV_REG_SP, store_offset, RV_REG_FP), ctx);
+ store_offset -= 8;
+ if (seen_reg(RV_REG_S1, ctx)) {
+ emit(rv_sd(RV_REG_SP, store_offset, RV_REG_S1), ctx);
+ store_offset -= 8;
+ }
+ if (seen_reg(RV_REG_S2, ctx)) {
+ emit(rv_sd(RV_REG_SP, store_offset, RV_REG_S2), ctx);
+ store_offset -= 8;
+ }
+ if (seen_reg(RV_REG_S3, ctx)) {
+ emit(rv_sd(RV_REG_SP, store_offset, RV_REG_S3), ctx);
+ store_offset -= 8;
+ }
+ if (seen_reg(RV_REG_S4, ctx)) {
+ emit(rv_sd(RV_REG_SP, store_offset, RV_REG_S4), ctx);
+ store_offset -= 8;
+ }
+ if (seen_reg(RV_REG_S5, ctx)) {
+ emit(rv_sd(RV_REG_SP, store_offset, RV_REG_S5), ctx);
+ store_offset -= 8;
+ }
+ if (seen_reg(RV_REG_S6, ctx)) {
+ emit(rv_sd(RV_REG_SP, store_offset, RV_REG_S6), ctx);
+ store_offset -= 8;
+ }
+
+ emit(rv_addi(RV_REG_FP, RV_REG_SP, stack_adjust), ctx);
+
+ if (bpf_stack_adjust)
+ emit(rv_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(rv_addi(RV_REG_TCC_SAVED, RV_REG_TCC, 0), ctx);
+
+ ctx->stack_size = stack_adjust;
+}
+
+static void build_epilogue(struct rv_jit_context *ctx)
+{
+ __build_epilogue(RV_REG_RA, ctx);
+}
+
+static int build_body(struct rv_jit_context *ctx, bool extra_pass)
+{
+ 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 = emit_insn(insn, ctx, extra_pass);
+ if (ret > 0) {
+ i++;
+ if (ctx->insns == NULL)
+ ctx->offset[i] = ctx->ninsns;
+ continue;
+ }
+ if (ctx->insns == NULL)
+ ctx->offset[i] = ctx->ninsns;
+ if (ret)
+ return ret;
+ }
+ return 0;
+}
+
+static void bpf_fill_ill_insns(void *area, unsigned int size)
+{
+ memset(area, 0, size);
+}
+
+static void bpf_flush_icache(void *start, void *end)
+{
+ flush_icache_range((unsigned long)start, (unsigned long)end);
+}
+
+struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
+{
+ bool tmp_blinded = false, extra_pass = false;
+ struct bpf_prog *tmp, *orig_prog = prog;
+ struct rv_jit_data *jit_data;
+ struct rv_jit_context *ctx;
+ unsigned int image_size;
+
+ 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;
+ image_size = sizeof(u32) * 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;
+ }
+
+ /* First pass generates the ctx->offset, but does not emit an image. */
+ if (build_body(ctx, extra_pass)) {
+ prog = orig_prog;
+ goto out_offset;
+ }
+ build_prologue(ctx);
+ ctx->epilogue_offset = ctx->ninsns;
+ build_epilogue(ctx);
+
+ /* Allocate image, now that we know the size. */
+ image_size = sizeof(u32) * ctx->ninsns;
+ jit_data->header = bpf_jit_binary_alloc(image_size, &jit_data->image,
+ sizeof(u32),
+ bpf_fill_ill_insns);
+ if (!jit_data->header) {
+ prog = orig_prog;
+ goto out_offset;
+ }
+
+ /* Second, real pass, that acutally emits the image. */
+ ctx->insns = (u32 *)jit_data->image;
+skip_init_ctx:
+ ctx->ninsns = 0;
+
+ build_prologue(ctx);
+ if (build_body(ctx, extra_pass)) {
+ bpf_jit_binary_free(jit_data->header);
+ prog = orig_prog;
+ goto out_offset;
+ }
+ build_epilogue(ctx);
+
+ if (bpf_jit_enable > 1)
+ bpf_jit_dump(prog->len, image_size, 2, ctx->insns);
+
+ prog->bpf_func = (void *)ctx->insns;
+ prog->jited = 1;
+ prog->jited_len = image_size;
+
+ bpf_flush_icache(jit_data->header, ctx->insns + ctx->ninsns);
+
+ if (!prog->is_func || extra_pass) {
+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;
+}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.