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-rw-r--r--arch/riscv/net/bpf_jit.h483
1 files changed, 480 insertions, 3 deletions
diff --git a/arch/riscv/net/bpf_jit.h b/arch/riscv/net/bpf_jit.h
index 20e235d06f66..75c1e9996867 100644
--- a/arch/riscv/net/bpf_jit.h
+++ b/arch/riscv/net/bpf_jit.h
@@ -13,6 +13,11 @@
#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 */
@@ -48,9 +53,21 @@ enum {
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;
- u32 *insns; /* RV insns */
+ u16 *insns; /* RV insns */
int ninsns;
int epilogue_offset;
int *offset; /* BPF to RV */
@@ -58,6 +75,12 @@ struct rv_jit_context {
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;
@@ -74,8 +97,22 @@ 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;
@@ -86,7 +123,7 @@ static inline int epilogue_offset(struct rv_jit_context *ctx)
{
int to = ctx->epilogue_offset, from = ctx->ninsns;
- return (to - from) << 2;
+ return ninsns_rvoff(to - from);
}
/* Return -1 or inverted cond. */
@@ -117,6 +154,36 @@ static inline int invert_bpf_cond(u8 cond)
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);
@@ -149,7 +216,7 @@ static inline int rv_offset(int insn, int off, struct rv_jit_context *ctx)
off++; /* BPF branch is from PC+1, RV is from PC */
from = (insn > 0) ? ctx->offset[insn - 1] : 0;
to = (insn + off > 0) ? ctx->offset[insn + off - 1] : 0;
- return (to - from) << 2;
+ return ninsns_rvoff(to - from);
}
/* Instruction formats. */
@@ -207,6 +274,59 @@ static inline u32 rv_amo_insn(u8 funct5, u8 aq, u8 rl, u8 rs2, u8 rs1,
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)
@@ -414,6 +534,135 @@ 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);
}
+/* 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.
*
@@ -503,6 +752,234 @@ 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);
}
+/* 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);