* [PATCH bpf-next v2 3/4] LoongArch: Add BPF JIT support
2022-08-30 11:10 [PATCH bpf-next v2 0/4] Add BPF JIT support for LoongArch Tiezhu Yang
2022-08-30 11:10 ` [PATCH bpf-next v2 1/4] LoongArch: Move {signed,unsigned}_imm_check() to inst.h Tiezhu Yang
2022-08-30 11:10 ` [PATCH bpf-next v2 2/4] LoongArch: Add some instruction opcodes and formats Tiezhu Yang
@ 2022-08-30 11:10 ` Tiezhu Yang
2022-08-30 11:10 ` [PATCH bpf-next v2 4/4] LoongArch: Enable BPF_JIT and TEST_BPF in default config Tiezhu Yang
3 siblings, 0 replies; 11+ messages in thread
From: Tiezhu Yang @ 2022-08-30 11:10 UTC (permalink / raw)
To: Huacai Chen, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko
Cc: bpf, loongarch
BPF programs are normally handled by a BPF interpreter, add BPF JIT
support for LoongArch to allow the kernel to generate native code
when a program is loaded into the kernel, this will significantly
speed-up processing of BPF programs.
Co-developed-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---
arch/loongarch/Kbuild | 1 +
arch/loongarch/Kconfig | 1 +
arch/loongarch/include/asm/inst.h | 221 +++++++
arch/loongarch/net/Makefile | 7 +
arch/loongarch/net/bpf_jit.c | 1160 +++++++++++++++++++++++++++++++++++++
arch/loongarch/net/bpf_jit.h | 282 +++++++++
6 files changed, 1672 insertions(+)
create mode 100644 arch/loongarch/net/Makefile
create mode 100644 arch/loongarch/net/bpf_jit.c
create mode 100644 arch/loongarch/net/bpf_jit.h
diff --git a/arch/loongarch/Kbuild b/arch/loongarch/Kbuild
index ab5373d..b01f5cd 100644
--- a/arch/loongarch/Kbuild
+++ b/arch/loongarch/Kbuild
@@ -1,5 +1,6 @@
obj-y += kernel/
obj-y += mm/
+obj-y += net/
obj-y += vdso/
# for cleaning
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index 26aeb14..cff7a0f 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -82,6 +82,7 @@ config LOONGARCH
select HAVE_CONTEXT_TRACKING_USER
select HAVE_DEBUG_STACKOVERFLOW
select HAVE_DMA_CONTIGUOUS
+ select HAVE_EBPF_JIT if 64BIT
select HAVE_EXIT_THREAD
select HAVE_FAST_GUP
select HAVE_GENERIC_VDSO
diff --git a/arch/loongarch/include/asm/inst.h b/arch/loongarch/include/asm/inst.h
index 691170b..5e7a4d2 100644
--- a/arch/loongarch/include/asm/inst.h
+++ b/arch/loongarch/include/asm/inst.h
@@ -318,4 +318,225 @@ static inline bool unsigned_imm_check(unsigned long val, unsigned int bit)
return val < (1UL << bit);
}
+#define DEF_EMIT_REG0I26_FORMAT(NAME, OP) \
+static inline void emit_##NAME(union loongarch_instruction *insn, \
+ int offset) \
+{ \
+ unsigned int immediate_l, immediate_h; \
+ \
+ immediate_l = offset & 0xffff; \
+ offset >>= 16; \
+ immediate_h = offset & 0x3ff; \
+ \
+ insn->reg0i26_format.opcode = OP; \
+ insn->reg0i26_format.immediate_l = immediate_l; \
+ insn->reg0i26_format.immediate_h = immediate_h; \
+}
+
+DEF_EMIT_REG0I26_FORMAT(b, b_op)
+
+#define DEF_EMIT_REG1I20_FORMAT(NAME, OP) \
+static inline void emit_##NAME(union loongarch_instruction *insn, \
+ enum loongarch_gpr rd, int imm) \
+{ \
+ insn->reg1i20_format.opcode = OP; \
+ insn->reg1i20_format.immediate = imm; \
+ insn->reg1i20_format.rd = rd; \
+}
+
+DEF_EMIT_REG1I20_FORMAT(lu12iw, lu12iw_op)
+DEF_EMIT_REG1I20_FORMAT(lu32id, lu32id_op)
+DEF_EMIT_REG1I20_FORMAT(pcaddu18i, pcaddu18i_op)
+
+#define DEF_EMIT_REG2_FORMAT(NAME, OP) \
+static inline void emit_##NAME(union loongarch_instruction *insn, \
+ enum loongarch_gpr rd, \
+ enum loongarch_gpr rj) \
+{ \
+ insn->reg2_format.opcode = OP; \
+ insn->reg2_format.rd = rd; \
+ insn->reg2_format.rj = rj; \
+}
+
+DEF_EMIT_REG2_FORMAT(revb2h, revb2h_op)
+DEF_EMIT_REG2_FORMAT(revb2w, revb2w_op)
+DEF_EMIT_REG2_FORMAT(revbd, revbd_op)
+
+#define DEF_EMIT_REG2I5_FORMAT(NAME, OP) \
+static inline void emit_##NAME(union loongarch_instruction *insn, \
+ enum loongarch_gpr rd, \
+ enum loongarch_gpr rj, \
+ int imm) \
+{ \
+ insn->reg2i5_format.opcode = OP; \
+ insn->reg2i5_format.immediate = imm; \
+ insn->reg2i5_format.rd = rd; \
+ insn->reg2i5_format.rj = rj; \
+}
+
+DEF_EMIT_REG2I5_FORMAT(slliw, slliw_op)
+DEF_EMIT_REG2I5_FORMAT(srliw, srliw_op)
+DEF_EMIT_REG2I5_FORMAT(sraiw, sraiw_op)
+
+#define DEF_EMIT_REG2I6_FORMAT(NAME, OP) \
+static inline void emit_##NAME(union loongarch_instruction *insn, \
+ enum loongarch_gpr rd, \
+ enum loongarch_gpr rj, \
+ int imm) \
+{ \
+ insn->reg2i6_format.opcode = OP; \
+ insn->reg2i6_format.immediate = imm; \
+ insn->reg2i6_format.rd = rd; \
+ insn->reg2i6_format.rj = rj; \
+}
+
+DEF_EMIT_REG2I6_FORMAT(sllid, sllid_op)
+DEF_EMIT_REG2I6_FORMAT(srlid, srlid_op)
+DEF_EMIT_REG2I6_FORMAT(sraid, sraid_op)
+
+#define DEF_EMIT_REG2I12_FORMAT(NAME, OP) \
+static inline void emit_##NAME(union loongarch_instruction *insn, \
+ enum loongarch_gpr rd, \
+ enum loongarch_gpr rj, \
+ int imm) \
+{ \
+ insn->reg2i12_format.opcode = OP; \
+ insn->reg2i12_format.immediate = imm; \
+ insn->reg2i12_format.rd = rd; \
+ insn->reg2i12_format.rj = rj; \
+}
+
+DEF_EMIT_REG2I12_FORMAT(addiw, addiw_op)
+DEF_EMIT_REG2I12_FORMAT(addid, addid_op)
+DEF_EMIT_REG2I12_FORMAT(lu52id, lu52id_op)
+DEF_EMIT_REG2I12_FORMAT(andi, andi_op)
+DEF_EMIT_REG2I12_FORMAT(ori, ori_op)
+DEF_EMIT_REG2I12_FORMAT(xori, xori_op)
+DEF_EMIT_REG2I12_FORMAT(ldbu, ldbu_op)
+DEF_EMIT_REG2I12_FORMAT(ldhu, ldhu_op)
+DEF_EMIT_REG2I12_FORMAT(ldwu, ldwu_op)
+DEF_EMIT_REG2I12_FORMAT(ldd, ldd_op)
+DEF_EMIT_REG2I12_FORMAT(stb, stb_op)
+DEF_EMIT_REG2I12_FORMAT(sth, sth_op)
+DEF_EMIT_REG2I12_FORMAT(stw, stw_op)
+DEF_EMIT_REG2I12_FORMAT(std, std_op)
+
+#define DEF_EMIT_REG2I14_FORMAT(NAME, OP) \
+static inline void emit_##NAME(union loongarch_instruction *insn, \
+ enum loongarch_gpr rd, \
+ enum loongarch_gpr rj, \
+ int imm) \
+{ \
+ insn->reg2i14_format.opcode = OP; \
+ insn->reg2i14_format.immediate = imm; \
+ insn->reg2i14_format.rd = rd; \
+ insn->reg2i14_format.rj = rj; \
+}
+
+DEF_EMIT_REG2I14_FORMAT(llw, llw_op)
+DEF_EMIT_REG2I14_FORMAT(scw, scw_op)
+DEF_EMIT_REG2I14_FORMAT(lld, lld_op)
+DEF_EMIT_REG2I14_FORMAT(scd, scd_op)
+DEF_EMIT_REG2I14_FORMAT(ldptrw, ldptrw_op)
+DEF_EMIT_REG2I14_FORMAT(stptrw, stptrw_op)
+DEF_EMIT_REG2I14_FORMAT(ldptrd, ldptrd_op)
+DEF_EMIT_REG2I14_FORMAT(stptrd, stptrd_op)
+
+#define DEF_EMIT_REG2I16_FORMAT(NAME, OP) \
+static inline void emit_##NAME(union loongarch_instruction *insn, \
+ enum loongarch_gpr rj, \
+ enum loongarch_gpr rd, \
+ int offset) \
+{ \
+ insn->reg2i16_format.opcode = OP; \
+ insn->reg2i16_format.immediate = offset; \
+ insn->reg2i16_format.rj = rj; \
+ insn->reg2i16_format.rd = rd; \
+}
+
+DEF_EMIT_REG2I16_FORMAT(beq, beq_op)
+DEF_EMIT_REG2I16_FORMAT(bne, bne_op)
+DEF_EMIT_REG2I16_FORMAT(blt, blt_op)
+DEF_EMIT_REG2I16_FORMAT(bge, bge_op)
+DEF_EMIT_REG2I16_FORMAT(bltu, bltu_op)
+DEF_EMIT_REG2I16_FORMAT(bgeu, bgeu_op)
+DEF_EMIT_REG2I16_FORMAT(jirl, jirl_op)
+
+#define DEF_EMIT_REG2BSTRD_FORMAT(NAME, OP) \
+static inline void emit_##NAME(union loongarch_instruction *insn, \
+ enum loongarch_gpr rd, \
+ enum loongarch_gpr rj, \
+ int msbd, \
+ int lsbd) \
+{ \
+ insn->reg2bstrd_format.opcode = OP; \
+ insn->reg2bstrd_format.msbd = msbd; \
+ insn->reg2bstrd_format.lsbd = lsbd; \
+ insn->reg2bstrd_format.rj = rj; \
+ insn->reg2bstrd_format.rd = rd; \
+}
+
+DEF_EMIT_REG2BSTRD_FORMAT(bstrpickd, bstrpickd_op)
+
+#define DEF_EMIT_REG3_FORMAT(NAME, OP) \
+static inline void emit_##NAME(union loongarch_instruction *insn, \
+ enum loongarch_gpr rd, \
+ enum loongarch_gpr rj, \
+ enum loongarch_gpr rk) \
+{ \
+ insn->reg3_format.opcode = OP; \
+ insn->reg3_format.rd = rd; \
+ insn->reg3_format.rj = rj; \
+ insn->reg3_format.rk = rk; \
+}
+
+DEF_EMIT_REG3_FORMAT(addd, addd_op)
+DEF_EMIT_REG3_FORMAT(subd, subd_op)
+DEF_EMIT_REG3_FORMAT(muld, muld_op)
+DEF_EMIT_REG3_FORMAT(divdu, divdu_op)
+DEF_EMIT_REG3_FORMAT(moddu, moddu_op)
+DEF_EMIT_REG3_FORMAT(and, and_op)
+DEF_EMIT_REG3_FORMAT(or, or_op)
+DEF_EMIT_REG3_FORMAT(xor, xor_op)
+DEF_EMIT_REG3_FORMAT(sllw, sllw_op)
+DEF_EMIT_REG3_FORMAT(slld, slld_op)
+DEF_EMIT_REG3_FORMAT(srlw, srlw_op)
+DEF_EMIT_REG3_FORMAT(srld, srld_op)
+DEF_EMIT_REG3_FORMAT(sraw, sraw_op)
+DEF_EMIT_REG3_FORMAT(srad, srad_op)
+DEF_EMIT_REG3_FORMAT(ldxbu, ldxbu_op)
+DEF_EMIT_REG3_FORMAT(ldxhu, ldxhu_op)
+DEF_EMIT_REG3_FORMAT(ldxwu, ldxwu_op)
+DEF_EMIT_REG3_FORMAT(ldxd, ldxd_op)
+DEF_EMIT_REG3_FORMAT(stxb, stxb_op)
+DEF_EMIT_REG3_FORMAT(stxh, stxh_op)
+DEF_EMIT_REG3_FORMAT(stxw, stxw_op)
+DEF_EMIT_REG3_FORMAT(stxd, stxd_op)
+DEF_EMIT_REG3_FORMAT(amaddw, amaddw_op)
+DEF_EMIT_REG3_FORMAT(amaddd, amaddd_op)
+DEF_EMIT_REG3_FORMAT(amandw, amandw_op)
+DEF_EMIT_REG3_FORMAT(amandd, amandd_op)
+DEF_EMIT_REG3_FORMAT(amorw, amorw_op)
+DEF_EMIT_REG3_FORMAT(amord, amord_op)
+DEF_EMIT_REG3_FORMAT(amxorw, amxorw_op)
+DEF_EMIT_REG3_FORMAT(amxord, amxord_op)
+DEF_EMIT_REG3_FORMAT(amswapw, amswapw_op)
+DEF_EMIT_REG3_FORMAT(amswapd, amswapd_op)
+
+#define DEF_EMIT_REG3SA2_FORMAT(NAME, OP) \
+static inline void emit_##NAME(union loongarch_instruction *insn, \
+ enum loongarch_gpr rd, \
+ enum loongarch_gpr rj, \
+ enum loongarch_gpr rk, \
+ int imm) \
+{ \
+ insn->reg3sa2_format.opcode = OP; \
+ insn->reg3sa2_format.immediate = imm; \
+ insn->reg3sa2_format.rd = rd; \
+ insn->reg3sa2_format.rj = rj; \
+ insn->reg3sa2_format.rk = rk; \
+}
+
+DEF_EMIT_REG3SA2_FORMAT(alsld, alsld_op)
+
#endif /* _ASM_INST_H */
diff --git a/arch/loongarch/net/Makefile b/arch/loongarch/net/Makefile
new file mode 100644
index 0000000..1ec12a0
--- /dev/null
+++ b/arch/loongarch/net/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for arch/loongarch/net
+#
+# Copyright (C) 2022 Loongson Technology Corporation Limited
+#
+obj-$(CONFIG_BPF_JIT) += bpf_jit.o
diff --git a/arch/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c
new file mode 100644
index 0000000..e9c9ce9
--- /dev/null
+++ b/arch/loongarch/net/bpf_jit.c
@@ -0,0 +1,1160 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * BPF JIT compiler for LoongArch
+ *
+ * Copyright (C) 2022 Loongson Technology Corporation Limited
+ */
+#include "bpf_jit.h"
+
+#define REG_TCC LOONGARCH_GPR_A6
+#define TCC_SAVED LOONGARCH_GPR_S5
+
+#define SAVE_RA BIT(0)
+#define SAVE_TCC BIT(1)
+
+static const int regmap[] = {
+ /* return value from in-kernel function, and exit value for eBPF program */
+ [BPF_REG_0] = LOONGARCH_GPR_A5,
+ /* arguments from eBPF program to in-kernel function */
+ [BPF_REG_1] = LOONGARCH_GPR_A0,
+ [BPF_REG_2] = LOONGARCH_GPR_A1,
+ [BPF_REG_3] = LOONGARCH_GPR_A2,
+ [BPF_REG_4] = LOONGARCH_GPR_A3,
+ [BPF_REG_5] = LOONGARCH_GPR_A4,
+ /* callee saved registers that in-kernel function will preserve */
+ [BPF_REG_6] = LOONGARCH_GPR_S0,
+ [BPF_REG_7] = LOONGARCH_GPR_S1,
+ [BPF_REG_8] = LOONGARCH_GPR_S2,
+ [BPF_REG_9] = LOONGARCH_GPR_S3,
+ /* read-only frame pointer to access stack */
+ [BPF_REG_FP] = LOONGARCH_GPR_S4,
+ /* temporary register for blinding constants */
+ [BPF_REG_AX] = LOONGARCH_GPR_T0,
+};
+
+static void mark_call(struct jit_ctx *ctx)
+{
+ ctx->flags |= SAVE_RA;
+}
+
+static void mark_tail_call(struct jit_ctx *ctx)
+{
+ ctx->flags |= SAVE_TCC;
+}
+
+static bool seen_call(struct jit_ctx *ctx)
+{
+ return (ctx->flags & SAVE_RA);
+}
+
+static bool seen_tail_call(struct jit_ctx *ctx)
+{
+ return (ctx->flags & SAVE_TCC);
+}
+
+static u8 tail_call_reg(struct jit_ctx *ctx)
+{
+ if (seen_call(ctx))
+ return TCC_SAVED;
+
+ return REG_TCC;
+}
+
+/*
+ * eBPF prog stack layout:
+ *
+ * high
+ * original $sp ------------> +-------------------------+ <--LOONGARCH_GPR_FP
+ * | $ra |
+ * +-------------------------+
+ * | $fp |
+ * +-------------------------+
+ * | $s0 |
+ * +-------------------------+
+ * | $s1 |
+ * +-------------------------+
+ * | $s2 |
+ * +-------------------------+
+ * | $s3 |
+ * +-------------------------+
+ * | $s4 |
+ * +-------------------------+
+ * | $s5 |
+ * +-------------------------+ <--BPF_REG_FP
+ * | prog->aux->stack_depth |
+ * | (optional) |
+ * current $sp -------------> +-------------------------+
+ * low
+ */
+static void build_prologue(struct jit_ctx *ctx)
+{
+ int stack_adjust = 0, store_offset, bpf_stack_adjust;
+
+ bpf_stack_adjust = round_up(ctx->prog->aux->stack_depth, 16);
+
+ /* To store ra, fp, s0, s1, s2, s3, s4 and s5. */
+ stack_adjust += sizeof(long) * 8;
+
+ stack_adjust = round_up(stack_adjust, 16);
+ stack_adjust += bpf_stack_adjust;
+
+ /*
+ * First instruction initializes the tail call count (TCC).
+ * On tail call we skip this instruction, and the TCC is
+ * passed in REG_TCC from the caller.
+ */
+ emit_insn(ctx, addid, REG_TCC, LOONGARCH_GPR_ZERO, MAX_TAIL_CALL_CNT);
+
+ emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, -stack_adjust);
+
+ store_offset = stack_adjust - sizeof(long);
+ emit_insn(ctx, std, LOONGARCH_GPR_RA, LOONGARCH_GPR_SP, store_offset);
+
+ store_offset -= sizeof(long);
+ emit_insn(ctx, std, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, store_offset);
+
+ store_offset -= sizeof(long);
+ emit_insn(ctx, std, LOONGARCH_GPR_S0, LOONGARCH_GPR_SP, store_offset);
+
+ store_offset -= sizeof(long);
+ emit_insn(ctx, std, LOONGARCH_GPR_S1, LOONGARCH_GPR_SP, store_offset);
+
+ store_offset -= sizeof(long);
+ emit_insn(ctx, std, LOONGARCH_GPR_S2, LOONGARCH_GPR_SP, store_offset);
+
+ store_offset -= sizeof(long);
+ emit_insn(ctx, std, LOONGARCH_GPR_S3, LOONGARCH_GPR_SP, store_offset);
+
+ store_offset -= sizeof(long);
+ emit_insn(ctx, std, LOONGARCH_GPR_S4, LOONGARCH_GPR_SP, store_offset);
+
+ store_offset -= sizeof(long);
+ emit_insn(ctx, std, LOONGARCH_GPR_S5, LOONGARCH_GPR_SP, store_offset);
+
+ emit_insn(ctx, addid, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_adjust);
+
+ if (bpf_stack_adjust)
+ emit_insn(ctx, addid, regmap[BPF_REG_FP], LOONGARCH_GPR_SP, bpf_stack_adjust);
+
+ /*
+ * Program contains calls and tail calls, so REG_TCC need
+ * to be saved across calls.
+ */
+ if (seen_tail_call(ctx) && seen_call(ctx))
+ move_reg(ctx, TCC_SAVED, REG_TCC);
+
+ ctx->stack_size = stack_adjust;
+}
+
+static void __build_epilogue(struct jit_ctx *ctx, bool is_tail_call)
+{
+ int stack_adjust = ctx->stack_size;
+ int load_offset;
+
+ load_offset = stack_adjust - sizeof(long);
+ emit_insn(ctx, ldd, LOONGARCH_GPR_RA, LOONGARCH_GPR_SP, load_offset);
+
+ load_offset -= sizeof(long);
+ emit_insn(ctx, ldd, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, load_offset);
+
+ load_offset -= sizeof(long);
+ emit_insn(ctx, ldd, LOONGARCH_GPR_S0, LOONGARCH_GPR_SP, load_offset);
+
+ load_offset -= sizeof(long);
+ emit_insn(ctx, ldd, LOONGARCH_GPR_S1, LOONGARCH_GPR_SP, load_offset);
+
+ load_offset -= sizeof(long);
+ emit_insn(ctx, ldd, LOONGARCH_GPR_S2, LOONGARCH_GPR_SP, load_offset);
+
+ load_offset -= sizeof(long);
+ emit_insn(ctx, ldd, LOONGARCH_GPR_S3, LOONGARCH_GPR_SP, load_offset);
+
+ load_offset -= sizeof(long);
+ emit_insn(ctx, ldd, LOONGARCH_GPR_S4, LOONGARCH_GPR_SP, load_offset);
+
+ load_offset -= sizeof(long);
+ emit_insn(ctx, ldd, LOONGARCH_GPR_S5, LOONGARCH_GPR_SP, load_offset);
+
+ emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, stack_adjust);
+
+ if (!is_tail_call) {
+ /* Set return value */
+ move_reg(ctx, LOONGARCH_GPR_A0, regmap[BPF_REG_0]);
+ /* Return to the caller */
+ emit_insn(ctx, jirl, LOONGARCH_GPR_RA, LOONGARCH_GPR_ZERO, 0);
+ } else {
+ /*
+ * Call the next bpf prog and skip the first instruction
+ * of TCC initialization.
+ */
+ emit_insn(ctx, jirl, LOONGARCH_GPR_T3, LOONGARCH_GPR_ZERO, 1);
+ }
+}
+
+static void build_epilogue(struct jit_ctx *ctx)
+{
+ __build_epilogue(ctx, false);
+}
+
+bool bpf_jit_supports_kfunc_call(void)
+{
+ return true;
+}
+
+/* initialized on the first pass of build_body() */
+static int out_offset = -1;
+static int emit_bpf_tail_call(struct jit_ctx *ctx)
+{
+ int off;
+ u8 tcc = tail_call_reg(ctx);
+ u8 a1 = LOONGARCH_GPR_A1;
+ u8 a2 = LOONGARCH_GPR_A2;
+ u8 t1 = LOONGARCH_GPR_T1;
+ u8 t2 = LOONGARCH_GPR_T2;
+ u8 t3 = LOONGARCH_GPR_T3;
+ const int idx0 = ctx->idx;
+
+#define cur_offset (ctx->idx - idx0)
+#define jmp_offset (out_offset - (cur_offset))
+
+ /*
+ * a0: &ctx
+ * a1: &array
+ * a2: index
+ *
+ * if (index >= array->map.max_entries)
+ * goto out;
+ */
+ off = offsetof(struct bpf_array, map.max_entries);
+ emit_insn(ctx, ldwu, t1, a1, off);
+ /* bgeu $a2, $t1, jmp_offset */
+ if (emit_tailcall_jmp(ctx, BPF_JGE, a2, t1, jmp_offset) < 0)
+ goto toofar;
+
+ /*
+ * if (--TCC < 0)
+ * goto out;
+ */
+ emit_insn(ctx, addid, REG_TCC, tcc, -1);
+ if (emit_tailcall_jmp(ctx, BPF_JSLT, REG_TCC, LOONGARCH_GPR_ZERO, jmp_offset) < 0)
+ goto toofar;
+
+ /*
+ * prog = array->ptrs[index];
+ * if (!prog)
+ * goto out;
+ */
+ emit_insn(ctx, alsld, t2, a2, a1, 2);
+ off = offsetof(struct bpf_array, ptrs);
+ emit_insn(ctx, ldd, t2, t2, off);
+ /* beq $t2, $zero, jmp_offset */
+ if (emit_tailcall_jmp(ctx, BPF_JEQ, t2, LOONGARCH_GPR_ZERO, jmp_offset) < 0)
+ goto toofar;
+
+ /* goto *(prog->bpf_func + 4); */
+ off = offsetof(struct bpf_prog, bpf_func);
+ emit_insn(ctx, ldd, t3, t2, off);
+ __build_epilogue(ctx, true);
+
+ /* out: */
+ if (out_offset == -1)
+ out_offset = cur_offset;
+ if (cur_offset != out_offset) {
+ pr_err_once("tail_call out_offset = %d, expected %d!\n",
+ cur_offset, out_offset);
+ return -1;
+ }
+
+ return 0;
+
+toofar:
+ pr_info_once("tail_call: jump too far\n");
+ return -1;
+#undef cur_offset
+#undef jmp_offset
+}
+
+static void emit_atomic(const struct bpf_insn *insn, struct jit_ctx *ctx)
+{
+ const u8 dst = regmap[insn->dst_reg];
+ const u8 src = regmap[insn->src_reg];
+ const u8 t1 = LOONGARCH_GPR_T1;
+ const u8 t2 = LOONGARCH_GPR_T2;
+ const u8 t3 = LOONGARCH_GPR_T3;
+ const s16 off = insn->off;
+ const s32 imm = insn->imm;
+ const bool isdw = BPF_SIZE(insn->code) == BPF_DW;
+
+ move_imm(ctx, t1, off, false);
+ emit_insn(ctx, addd, t1, dst, t1);
+ move_reg(ctx, t3, src);
+
+ switch (imm) {
+ /* lock *(size *)(dst + off) <op>= src */
+ case BPF_ADD:
+ if (isdw)
+ emit_insn(ctx, amaddd, t2, t1, src);
+ else
+ emit_insn(ctx, amaddw, t2, t1, src);
+ break;
+ case BPF_AND:
+ if (isdw)
+ emit_insn(ctx, amandd, t2, t1, src);
+ else
+ emit_insn(ctx, amandw, t2, t1, src);
+ break;
+ case BPF_OR:
+ if (isdw)
+ emit_insn(ctx, amord, t2, t1, src);
+ else
+ emit_insn(ctx, amorw, t2, t1, src);
+ break;
+ case BPF_XOR:
+ if (isdw)
+ emit_insn(ctx, amxord, t2, t1, src);
+ else
+ emit_insn(ctx, amxorw, t2, t1, src);
+ break;
+ /* src = atomic_fetch_<op>(dst + off, src) */
+ case BPF_ADD | BPF_FETCH:
+ if (isdw) {
+ emit_insn(ctx, amaddd, src, t1, t3);
+ } else {
+ emit_insn(ctx, amaddw, src, t1, t3);
+ emit_zext_32(ctx, src, true);
+ }
+ break;
+ case BPF_AND | BPF_FETCH:
+ if (isdw) {
+ emit_insn(ctx, amandd, src, t1, t3);
+ } else {
+ emit_insn(ctx, amandw, src, t1, t3);
+ emit_zext_32(ctx, src, true);
+ }
+ break;
+ case BPF_OR | BPF_FETCH:
+ if (isdw) {
+ emit_insn(ctx, amord, src, t1, t3);
+ } else {
+ emit_insn(ctx, amorw, src, t1, t3);
+ emit_zext_32(ctx, src, true);
+ }
+ break;
+ case BPF_XOR | BPF_FETCH:
+ if (isdw) {
+ emit_insn(ctx, amxord, src, t1, t3);
+ } else {
+ emit_insn(ctx, amxorw, src, t1, t3);
+ emit_zext_32(ctx, src, true);
+ }
+ break;
+ /* src = atomic_xchg(dst + off, src); */
+ case BPF_XCHG:
+ if (isdw) {
+ emit_insn(ctx, amswapd, src, t1, t3);
+ } else {
+ emit_insn(ctx, amswapw, src, t1, t3);
+ emit_zext_32(ctx, src, true);
+ }
+ break;
+ /* r0 = atomic_cmpxchg(dst + off, r0, src); */
+ case BPF_CMPXCHG:
+ u8 r0 = regmap[BPF_REG_0];
+
+ move_reg(ctx, t2, r0);
+ if (isdw) {
+ emit_insn(ctx, lld, r0, t1, 0);
+ emit_insn(ctx, bne, t2, r0, 4);
+ move_reg(ctx, t3, src);
+ emit_insn(ctx, scd, t3, t1, 0);
+ emit_insn(ctx, beq, t3, LOONGARCH_GPR_ZERO, -4);
+ } else {
+ emit_insn(ctx, llw, r0, t1, 0);
+ emit_zext_32(ctx, t2, true);
+ emit_zext_32(ctx, r0, true);
+ emit_insn(ctx, bne, t2, r0, 4);
+ move_reg(ctx, t3, src);
+ emit_insn(ctx, scw, t3, t1, 0);
+ emit_insn(ctx, beq, t3, LOONGARCH_GPR_ZERO, -6);
+ emit_zext_32(ctx, r0, true);
+ }
+ break;
+ }
+}
+
+static bool is_signed_bpf_cond(u8 cond)
+{
+ return cond == BPF_JSGT || cond == BPF_JSLT ||
+ cond == BPF_JSGE || cond == BPF_JSLE;
+}
+
+static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool extra_pass)
+{
+ const bool is32 = BPF_CLASS(insn->code) == BPF_ALU ||
+ BPF_CLASS(insn->code) == BPF_JMP32;
+ const u8 code = insn->code;
+ const u8 cond = BPF_OP(code);
+ const u8 dst = regmap[insn->dst_reg];
+ const u8 src = regmap[insn->src_reg];
+ const u8 t1 = LOONGARCH_GPR_T1;
+ const u8 t2 = LOONGARCH_GPR_T2;
+ const s16 off = insn->off;
+ const s32 imm = insn->imm;
+ int i = insn - ctx->prog->insnsi;
+ int jmp_offset;
+
+ switch (code) {
+ /* dst = src */
+ case BPF_ALU | BPF_MOV | BPF_X:
+ case BPF_ALU64 | BPF_MOV | BPF_X:
+ move_reg(ctx, dst, src);
+ emit_zext_32(ctx, dst, is32);
+ break;
+ /* dst = imm */
+ case BPF_ALU | BPF_MOV | BPF_K:
+ case BPF_ALU64 | BPF_MOV | BPF_K:
+ move_imm(ctx, dst, imm, is32);
+ break;
+
+ /* dst = dst + src */
+ case BPF_ALU | BPF_ADD | BPF_X:
+ case BPF_ALU64 | BPF_ADD | BPF_X:
+ emit_insn(ctx, addd, dst, dst, src);
+ emit_zext_32(ctx, dst, is32);
+ break;
+ /* dst = dst + imm */
+ case BPF_ALU | BPF_ADD | BPF_K:
+ case BPF_ALU64 | BPF_ADD | BPF_K:
+ if (is_signed_imm12(imm)) {
+ emit_insn(ctx, addid, dst, dst, imm);
+ } else {
+ move_imm(ctx, t1, imm, is32);
+ emit_insn(ctx, addd, dst, dst, t1);
+ }
+ emit_zext_32(ctx, dst, is32);
+ break;
+
+ /* dst = dst - src */
+ case BPF_ALU | BPF_SUB | BPF_X:
+ case BPF_ALU64 | BPF_SUB | BPF_X:
+ emit_insn(ctx, subd, dst, dst, src);
+ emit_zext_32(ctx, dst, is32);
+ break;
+ /* dst = dst - imm */
+ case BPF_ALU | BPF_SUB | BPF_K:
+ case BPF_ALU64 | BPF_SUB | BPF_K:
+ if (is_signed_imm12(-imm)) {
+ emit_insn(ctx, addid, dst, dst, -imm);
+ } else {
+ move_imm(ctx, t1, imm, is32);
+ emit_insn(ctx, subd, dst, dst, t1);
+ }
+ emit_zext_32(ctx, dst, is32);
+ break;
+
+ /* dst = dst * src */
+ case BPF_ALU | BPF_MUL | BPF_X:
+ case BPF_ALU64 | BPF_MUL | BPF_X:
+ emit_insn(ctx, muld, dst, dst, src);
+ emit_zext_32(ctx, dst, is32);
+ break;
+ /* dst = dst * imm */
+ case BPF_ALU | BPF_MUL | BPF_K:
+ case BPF_ALU64 | BPF_MUL | BPF_K:
+ move_imm(ctx, t1, imm, is32);
+ emit_insn(ctx, muld, dst, dst, t1);
+ emit_zext_32(ctx, dst, is32);
+ break;
+
+ /* dst = dst / src */
+ case BPF_ALU | BPF_DIV | BPF_X:
+ case BPF_ALU64 | BPF_DIV | BPF_X:
+ emit_zext_32(ctx, dst, is32);
+ move_reg(ctx, t1, src);
+ emit_zext_32(ctx, t1, is32);
+ emit_insn(ctx, divdu, dst, dst, t1);
+ emit_zext_32(ctx, dst, is32);
+ break;
+ /* dst = dst / imm */
+ case BPF_ALU | BPF_DIV | BPF_K:
+ case BPF_ALU64 | BPF_DIV | BPF_K:
+ move_imm(ctx, t1, imm, is32);
+ emit_zext_32(ctx, dst, is32);
+ emit_insn(ctx, divdu, dst, dst, t1);
+ emit_zext_32(ctx, dst, is32);
+ break;
+
+ /* dst = dst % src */
+ case BPF_ALU | BPF_MOD | BPF_X:
+ case BPF_ALU64 | BPF_MOD | BPF_X:
+ emit_zext_32(ctx, dst, is32);
+ move_reg(ctx, t1, src);
+ emit_zext_32(ctx, t1, is32);
+ emit_insn(ctx, moddu, dst, dst, t1);
+ emit_zext_32(ctx, dst, is32);
+ break;
+ /* dst = dst % imm */
+ case BPF_ALU | BPF_MOD | BPF_K:
+ case BPF_ALU64 | BPF_MOD | BPF_K:
+ move_imm(ctx, t1, imm, is32);
+ emit_zext_32(ctx, dst, is32);
+ emit_insn(ctx, moddu, dst, dst, t1);
+ emit_zext_32(ctx, dst, is32);
+ break;
+
+ /* dst = -dst */
+ case BPF_ALU | BPF_NEG:
+ case BPF_ALU64 | BPF_NEG:
+ move_imm(ctx, t1, imm, is32);
+ emit_insn(ctx, subd, dst, LOONGARCH_GPR_ZERO, dst);
+ emit_zext_32(ctx, dst, is32);
+ break;
+
+ /* dst = dst & src */
+ case BPF_ALU | BPF_AND | BPF_X:
+ case BPF_ALU64 | BPF_AND | BPF_X:
+ emit_insn(ctx, and, dst, dst, src);
+ emit_zext_32(ctx, dst, is32);
+ break;
+ /* dst = dst & imm */
+ case BPF_ALU | BPF_AND | BPF_K:
+ case BPF_ALU64 | BPF_AND | BPF_K:
+ if (is_unsigned_imm12(imm)) {
+ emit_insn(ctx, andi, dst, dst, imm);
+ } else {
+ move_imm(ctx, t1, imm, is32);
+ emit_insn(ctx, and, dst, dst, t1);
+ }
+ emit_zext_32(ctx, dst, is32);
+ break;
+
+ /* dst = dst | src */
+ case BPF_ALU | BPF_OR | BPF_X:
+ case BPF_ALU64 | BPF_OR | BPF_X:
+ emit_insn(ctx, or, dst, dst, src);
+ emit_zext_32(ctx, dst, is32);
+ break;
+ /* dst = dst | imm */
+ case BPF_ALU | BPF_OR | BPF_K:
+ case BPF_ALU64 | BPF_OR | BPF_K:
+ if (is_unsigned_imm12(imm)) {
+ emit_insn(ctx, ori, dst, dst, imm);
+ } else {
+ move_imm(ctx, t1, imm, is32);
+ emit_insn(ctx, or, dst, dst, t1);
+ }
+ emit_zext_32(ctx, dst, is32);
+ break;
+
+ /* dst = dst ^ src */
+ case BPF_ALU | BPF_XOR | BPF_X:
+ case BPF_ALU64 | BPF_XOR | BPF_X:
+ emit_insn(ctx, xor, dst, dst, src);
+ emit_zext_32(ctx, dst, is32);
+ break;
+ /* dst = dst ^ imm */
+ case BPF_ALU | BPF_XOR | BPF_K:
+ case BPF_ALU64 | BPF_XOR | BPF_K:
+ if (is_unsigned_imm12(imm)) {
+ emit_insn(ctx, xori, dst, dst, imm);
+ } else {
+ move_imm(ctx, t1, imm, is32);
+ emit_insn(ctx, xor, dst, dst, t1);
+ }
+ emit_zext_32(ctx, dst, is32);
+ break;
+
+ /* dst = dst << src (logical) */
+ case BPF_ALU | BPF_LSH | BPF_X:
+ emit_insn(ctx, sllw, dst, dst, src);
+ emit_zext_32(ctx, dst, is32);
+ break;
+ case BPF_ALU64 | BPF_LSH | BPF_X:
+ emit_insn(ctx, slld, dst, dst, src);
+ break;
+ /* dst = dst << imm (logical) */
+ case BPF_ALU | BPF_LSH | BPF_K:
+ emit_insn(ctx, slliw, dst, dst, imm);
+ emit_zext_32(ctx, dst, is32);
+ break;
+ case BPF_ALU64 | BPF_LSH | BPF_K:
+ emit_insn(ctx, sllid, dst, dst, imm);
+ break;
+
+ /* dst = dst >> src (logical) */
+ case BPF_ALU | BPF_RSH | BPF_X:
+ emit_insn(ctx, srlw, dst, dst, src);
+ emit_zext_32(ctx, dst, is32);
+ break;
+ case BPF_ALU64 | BPF_RSH | BPF_X:
+ emit_insn(ctx, srld, dst, dst, src);
+ break;
+ /* dst = dst >> imm (logical) */
+ case BPF_ALU | BPF_RSH | BPF_K:
+ emit_insn(ctx, srliw, dst, dst, imm);
+ emit_zext_32(ctx, dst, is32);
+ break;
+ case BPF_ALU64 | BPF_RSH | BPF_K:
+ emit_insn(ctx, srlid, dst, dst, imm);
+ break;
+
+ /* dst = dst >> src (arithmetic) */
+ case BPF_ALU | BPF_ARSH | BPF_X:
+ emit_insn(ctx, sraw, dst, dst, src);
+ emit_zext_32(ctx, dst, is32);
+ break;
+ case BPF_ALU64 | BPF_ARSH | BPF_X:
+ emit_insn(ctx, srad, dst, dst, src);
+ break;
+ /* dst = dst >> imm (arithmetic) */
+ case BPF_ALU | BPF_ARSH | BPF_K:
+ emit_insn(ctx, sraiw, dst, dst, imm);
+ emit_zext_32(ctx, dst, is32);
+ break;
+ case BPF_ALU64 | BPF_ARSH | BPF_K:
+ emit_insn(ctx, sraid, dst, dst, imm);
+ break;
+
+ /* dst = BSWAP##imm(dst) */
+ case BPF_ALU | BPF_END | BPF_FROM_LE:
+ switch (imm) {
+ case 16:
+ /* zero-extend 16 bits into 64 bits */
+ emit_insn(ctx, bstrpickd, dst, dst, 15, 0);
+ break;
+ case 32:
+ /* zero-extend 32 bits into 64 bits */
+ emit_zext_32(ctx, dst, is32);
+ break;
+ case 64:
+ /* do nothing */
+ break;
+ }
+ break;
+ case BPF_ALU | BPF_END | BPF_FROM_BE:
+ switch (imm) {
+ case 16:
+ emit_insn(ctx, revb2h, dst, dst);
+ /* zero-extend 16 bits into 64 bits */
+ emit_insn(ctx, bstrpickd, dst, dst, 15, 0);
+ break;
+ case 32:
+ emit_insn(ctx, revb2w, dst, dst);
+ /* zero-extend 32 bits into 64 bits */
+ emit_zext_32(ctx, dst, is32);
+ break;
+ case 64:
+ emit_insn(ctx, revbd, dst, dst);
+ break;
+ }
+ break;
+
+ /* PC += off if dst cond src */
+ case BPF_JMP | BPF_JEQ | BPF_X:
+ case BPF_JMP | BPF_JNE | BPF_X:
+ case BPF_JMP | BPF_JGT | BPF_X:
+ case BPF_JMP | BPF_JGE | BPF_X:
+ case BPF_JMP | BPF_JLT | BPF_X:
+ case BPF_JMP | BPF_JLE | BPF_X:
+ case BPF_JMP | BPF_JSGT | BPF_X:
+ case BPF_JMP | BPF_JSGE | BPF_X:
+ case BPF_JMP | BPF_JSLT | BPF_X:
+ case BPF_JMP | BPF_JSLE | BPF_X:
+ case BPF_JMP32 | BPF_JEQ | BPF_X:
+ case BPF_JMP32 | BPF_JNE | BPF_X:
+ case BPF_JMP32 | BPF_JGT | BPF_X:
+ case BPF_JMP32 | BPF_JGE | BPF_X:
+ case BPF_JMP32 | BPF_JLT | BPF_X:
+ case BPF_JMP32 | BPF_JLE | BPF_X:
+ case BPF_JMP32 | BPF_JSGT | BPF_X:
+ case BPF_JMP32 | BPF_JSGE | BPF_X:
+ case BPF_JMP32 | BPF_JSLT | BPF_X:
+ case BPF_JMP32 | BPF_JSLE | BPF_X:
+ jmp_offset = bpf2la_offset(i, off, ctx);
+ move_reg(ctx, t1, dst);
+ move_reg(ctx, t2, src);
+ if (is_signed_bpf_cond(BPF_OP(code))) {
+ emit_sext_32(ctx, t1, is32);
+ emit_sext_32(ctx, t2, is32);
+ } else {
+ emit_zext_32(ctx, t1, is32);
+ emit_zext_32(ctx, t2, is32);
+ }
+ if (emit_cond_jmp(ctx, cond, t1, t2, jmp_offset) < 0)
+ goto toofar;
+ break;
+
+ /* PC += off if dst cond imm */
+ case BPF_JMP | BPF_JEQ | BPF_K:
+ case BPF_JMP | BPF_JNE | BPF_K:
+ case BPF_JMP | BPF_JGT | BPF_K:
+ case BPF_JMP | BPF_JGE | BPF_K:
+ case BPF_JMP | BPF_JLT | BPF_K:
+ case BPF_JMP | BPF_JLE | BPF_K:
+ case BPF_JMP | BPF_JSGT | BPF_K:
+ case BPF_JMP | BPF_JSGE | BPF_K:
+ case BPF_JMP | BPF_JSLT | BPF_K:
+ case BPF_JMP | BPF_JSLE | BPF_K:
+ case BPF_JMP32 | BPF_JEQ | BPF_K:
+ case BPF_JMP32 | BPF_JNE | BPF_K:
+ case BPF_JMP32 | BPF_JGT | BPF_K:
+ case BPF_JMP32 | BPF_JGE | BPF_K:
+ case BPF_JMP32 | BPF_JLT | BPF_K:
+ case BPF_JMP32 | BPF_JLE | BPF_K:
+ case BPF_JMP32 | BPF_JSGT | BPF_K:
+ case BPF_JMP32 | BPF_JSGE | BPF_K:
+ case BPF_JMP32 | BPF_JSLT | BPF_K:
+ case BPF_JMP32 | BPF_JSLE | BPF_K:
+ u8 t7 = -1;
+ jmp_offset = bpf2la_offset(i, off, ctx);
+ if (imm) {
+ move_imm(ctx, t1, imm, false);
+ t7 = t1;
+ } else {
+ /* If imm is 0, simply use zero register. */
+ t7 = LOONGARCH_GPR_ZERO;
+ }
+ move_reg(ctx, t2, dst);
+ if (is_signed_bpf_cond(BPF_OP(code))) {
+ emit_sext_32(ctx, t7, is32);
+ emit_sext_32(ctx, t2, is32);
+ } else {
+ emit_zext_32(ctx, t7, is32);
+ emit_zext_32(ctx, t2, is32);
+ }
+ if (emit_cond_jmp(ctx, cond, t2, t7, jmp_offset) < 0)
+ goto toofar;
+ break;
+
+ /* PC += off if dst & src */
+ case BPF_JMP | BPF_JSET | BPF_X:
+ case BPF_JMP32 | BPF_JSET | BPF_X:
+ jmp_offset = bpf2la_offset(i, off, ctx);
+ emit_insn(ctx, and, t1, dst, src);
+ emit_zext_32(ctx, t1, is32);
+ if (emit_cond_jmp(ctx, cond, t1, LOONGARCH_GPR_ZERO, jmp_offset) < 0)
+ goto toofar;
+ break;
+ /* PC += off if dst & imm */
+ case BPF_JMP | BPF_JSET | BPF_K:
+ case BPF_JMP32 | BPF_JSET | BPF_K:
+ jmp_offset = bpf2la_offset(i, off, ctx);
+ move_imm(ctx, t1, imm, is32);
+ emit_insn(ctx, and, t1, dst, t1);
+ emit_zext_32(ctx, t1, is32);
+ if (emit_cond_jmp(ctx, cond, t1, LOONGARCH_GPR_ZERO, jmp_offset) < 0)
+ goto toofar;
+ break;
+
+ /* PC += off */
+ case BPF_JMP | BPF_JA:
+ jmp_offset = bpf2la_offset(i, off, ctx);
+ if (emit_uncond_jmp(ctx, jmp_offset) < 0)
+ goto toofar;
+ break;
+
+ /* function call */
+ case BPF_JMP | BPF_CALL:
+ bool func_addr_fixed;
+ u64 func_addr;
+ int ret;
+
+ mark_call(ctx);
+ ret = bpf_jit_get_func_addr(ctx->prog, insn, extra_pass,
+ &func_addr, &func_addr_fixed);
+ if (ret < 0)
+ return ret;
+
+ move_imm(ctx, t1, func_addr, is32);
+ emit_insn(ctx, jirl, t1, LOONGARCH_GPR_RA, 0);
+ move_reg(ctx, regmap[BPF_REG_0], LOONGARCH_GPR_A0);
+ break;
+
+ /* tail call */
+ case BPF_JMP | BPF_TAIL_CALL:
+ mark_tail_call(ctx);
+ if (emit_bpf_tail_call(ctx) < 0)
+ return -EINVAL;
+ break;
+
+ /* function return */
+ case BPF_JMP | BPF_EXIT:
+ emit_sext_32(ctx, regmap[BPF_REG_0], true);
+
+ if (i == ctx->prog->len - 1)
+ break;
+
+ jmp_offset = epilogue_offset(ctx);
+ if (emit_uncond_jmp(ctx, jmp_offset) < 0)
+ goto toofar;
+ break;
+
+ /* dst = imm64 */
+ case BPF_LD | BPF_IMM | BPF_DW:
+ u64 imm64 = (u64)(insn + 1)->imm << 32 | (u32)insn->imm;
+
+ move_imm(ctx, dst, imm64, is32);
+ return 1;
+
+ /* 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:
+ switch (BPF_SIZE(code)) {
+ case BPF_B:
+ if (is_signed_imm12(off)) {
+ emit_insn(ctx, ldbu, dst, src, off);
+ } else {
+ move_imm(ctx, t1, off, is32);
+ emit_insn(ctx, ldxbu, dst, src, t1);
+ }
+ break;
+ case BPF_H:
+ if (is_signed_imm12(off)) {
+ emit_insn(ctx, ldhu, dst, src, off);
+ } else {
+ move_imm(ctx, t1, off, is32);
+ emit_insn(ctx, ldxhu, dst, src, t1);
+ }
+ break;
+ case BPF_W:
+ if (is_signed_imm12(off)) {
+ emit_insn(ctx, ldwu, dst, src, off);
+ } else if (is_signed_imm14(off)) {
+ emit_insn(ctx, ldptrw, dst, src, off);
+ } else {
+ move_imm(ctx, t1, off, is32);
+ emit_insn(ctx, ldxwu, dst, src, t1);
+ }
+ break;
+ case BPF_DW:
+ if (is_signed_imm12(off)) {
+ emit_insn(ctx, ldd, dst, src, off);
+ } else if (is_signed_imm14(off)) {
+ emit_insn(ctx, ldptrd, dst, src, off);
+ } else {
+ move_imm(ctx, t1, off, is32);
+ emit_insn(ctx, ldxd, dst, src, t1);
+ }
+ break;
+ }
+ break;
+
+ /* *(size *)(dst + off) = imm */
+ 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:
+ switch (BPF_SIZE(code)) {
+ case BPF_B:
+ move_imm(ctx, t1, imm, is32);
+ if (is_signed_imm12(off)) {
+ emit_insn(ctx, stb, t1, dst, off);
+ } else {
+ move_imm(ctx, t2, off, is32);
+ emit_insn(ctx, stxb, t1, dst, t2);
+ }
+ break;
+ case BPF_H:
+ move_imm(ctx, t1, imm, is32);
+ if (is_signed_imm12(off)) {
+ emit_insn(ctx, sth, t1, dst, off);
+ } else {
+ move_imm(ctx, t2, off, is32);
+ emit_insn(ctx, stxh, t1, dst, t2);
+ }
+ break;
+ case BPF_W:
+ move_imm(ctx, t1, imm, is32);
+ if (is_signed_imm12(off)) {
+ emit_insn(ctx, stw, t1, dst, off);
+ } else if (is_signed_imm14(off)) {
+ emit_insn(ctx, stptrw, t1, dst, off);
+ } else {
+ move_imm(ctx, t2, off, is32);
+ emit_insn(ctx, stxw, t1, dst, t2);
+ }
+ break;
+ case BPF_DW:
+ move_imm(ctx, t1, imm, is32);
+ if (is_signed_imm12(off)) {
+ emit_insn(ctx, std, t1, dst, off);
+ } else if (is_signed_imm14(off)) {
+ emit_insn(ctx, stptrd, t1, dst, off);
+ } else {
+ move_imm(ctx, t2, off, is32);
+ emit_insn(ctx, stxd, t1, dst, t2);
+ }
+ break;
+ }
+ break;
+
+ /* *(size *)(dst + off) = src */
+ 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:
+ switch (BPF_SIZE(code)) {
+ case BPF_B:
+ if (is_signed_imm12(off)) {
+ emit_insn(ctx, stb, src, dst, off);
+ } else {
+ move_imm(ctx, t1, off, is32);
+ emit_insn(ctx, stxb, src, dst, t1);
+ }
+ break;
+ case BPF_H:
+ if (is_signed_imm12(off)) {
+ emit_insn(ctx, sth, src, dst, off);
+ } else {
+ move_imm(ctx, t1, off, is32);
+ emit_insn(ctx, stxh, src, dst, t1);
+ }
+ break;
+ case BPF_W:
+ if (is_signed_imm12(off)) {
+ emit_insn(ctx, stw, src, dst, off);
+ } else if (is_signed_imm14(off)) {
+ emit_insn(ctx, stptrw, src, dst, off);
+ } else {
+ move_imm(ctx, t1, off, is32);
+ emit_insn(ctx, stxw, src, dst, t1);
+ }
+ break;
+ case BPF_DW:
+ if (is_signed_imm12(off)) {
+ emit_insn(ctx, std, src, dst, off);
+ } else if (is_signed_imm14(off)) {
+ emit_insn(ctx, stptrd, src, dst, off);
+ } else {
+ move_imm(ctx, t1, off, is32);
+ emit_insn(ctx, stxd, src, dst, t1);
+ }
+ break;
+ }
+ break;
+
+ case BPF_STX | BPF_ATOMIC | BPF_W:
+ case BPF_STX | BPF_ATOMIC | BPF_DW:
+ emit_atomic(insn, ctx);
+ break;
+
+ default:
+ pr_err("bpf_jit: unknown opcode %02x\n", code);
+ return -EINVAL;
+ }
+
+ return 0;
+
+toofar:
+ pr_info_once("bpf_jit: opcode %02x, jump too far\n", code);
+ return -E2BIG;
+}
+
+static int build_body(struct jit_ctx *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;
+
+ if (ctx->image == NULL)
+ ctx->offset[i] = ctx->idx;
+
+ ret = build_insn(insn, ctx, extra_pass);
+ if (ret > 0) {
+ i++;
+ if (ctx->image == NULL)
+ ctx->offset[i] = ctx->idx;
+ continue;
+ }
+ if (ret)
+ return ret;
+ }
+
+ if (ctx->image == NULL)
+ ctx->offset[i] = ctx->idx;
+
+ return 0;
+}
+
+static inline void bpf_flush_icache(void *start, void *end)
+{
+ flush_icache_range((unsigned long)start, (unsigned long)end);
+}
+
+/* Fill space with illegal instructions */
+static void jit_fill_hole(void *area, unsigned int size)
+{
+ u32 *ptr;
+
+ /* We are guaranteed to have aligned memory */
+ for (ptr = area; size >= sizeof(u32); size -= sizeof(u32))
+ *ptr++ = INSN_BREAK;
+}
+
+static int validate_code(struct jit_ctx *ctx)
+{
+ int i;
+ union loongarch_instruction insn;
+
+ for (i = 0; i < ctx->idx; i++) {
+ insn = ctx->image[i];
+ /* Check INSN_BREAK */
+ if (insn.word == INSN_BREAK)
+ return -1;
+ }
+
+ return 0;
+}
+
+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 bpf_binary_header *header;
+ struct jit_data *jit_data;
+ struct jit_ctx ctx;
+ int image_size;
+ u8 *image_ptr;
+
+ /*
+ * If BPF JIT was not enabled then we must fall back to
+ * the interpreter.
+ */
+ if (!prog->jit_requested)
+ return orig_prog;
+
+ tmp = bpf_jit_blind_constants(prog);
+ /*
+ * If blinding was requested and we failed during blinding,
+ * we must fall back to the interpreter. Otherwise, we save
+ * the new JITed code.
+ */
+ 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;
+ }
+ if (jit_data->ctx.offset) {
+ ctx = jit_data->ctx;
+ image_ptr = jit_data->image;
+ header = jit_data->header;
+ extra_pass = true;
+ image_size = sizeof(u32) * ctx.idx;
+ goto skip_init_ctx;
+ }
+
+ memset(&ctx, 0, sizeof(ctx));
+ ctx.prog = prog;
+
+ ctx.offset = kvcalloc(prog->len + 1, sizeof(u32), GFP_KERNEL);
+ if (ctx.offset == NULL) {
+ prog = orig_prog;
+ goto out_offset;
+ }
+
+ /* 1. Initial fake pass to compute ctx->idx and set ctx->flags */
+ build_prologue(&ctx);
+ if (build_body(&ctx, extra_pass)) {
+ prog = orig_prog;
+ goto out_offset;
+ }
+ ctx.epilogue_offset = ctx.idx;
+ build_epilogue(&ctx);
+
+ /* Now we know the actual image size.
+ * As each LoongArch instruction is of length 32bit,
+ * we are translating number of JITed intructions into
+ * the size required to store these JITed code.
+ */
+ image_size = sizeof(u32) * ctx.idx;
+ /* Now we know the size of the structure to make */
+ header = bpf_jit_binary_alloc(image_size, &image_ptr,
+ sizeof(u32), jit_fill_hole);
+ if (header == NULL) {
+ prog = orig_prog;
+ goto out_offset;
+ }
+
+ /* 2. Now, the actual pass to generate final JIT code */
+ ctx.image = (union loongarch_instruction *)image_ptr;
+skip_init_ctx:
+ ctx.idx = 0;
+
+ build_prologue(&ctx);
+ if (build_body(&ctx, extra_pass)) {
+ bpf_jit_binary_free(header);
+ prog = orig_prog;
+ goto out_offset;
+ }
+ build_epilogue(&ctx);
+
+ /* 3. Extra pass to validate JITed code */
+ if (validate_code(&ctx)) {
+ bpf_jit_binary_free(header);
+ prog = orig_prog;
+ goto out_offset;
+ }
+
+ /* And we're done */
+ if (bpf_jit_enable > 1)
+ bpf_jit_dump(prog->len, image_size, 2, ctx.image);
+
+ /* Update the icache */
+ bpf_flush_icache(header, ctx.image + ctx.idx);
+
+ if (!prog->is_func || extra_pass) {
+ if (extra_pass && ctx.idx != jit_data->ctx.idx) {
+ pr_err_once("multi-func JIT bug %d != %d\n",
+ ctx.idx, jit_data->ctx.idx);
+ bpf_jit_binary_free(header);
+ prog->bpf_func = NULL;
+ prog->jited = 0;
+ prog->jited_len = 0;
+ goto out_offset;
+ }
+ bpf_jit_binary_lock_ro(header);
+ } else {
+ jit_data->ctx = ctx;
+ jit_data->image = image_ptr;
+ jit_data->header = header;
+ }
+ prog->bpf_func = (void *)ctx.image;
+ prog->jited = 1;
+ prog->jited_len = image_size;
+
+ if (!prog->is_func || extra_pass) {
+ int i;
+
+ /* offset[prog->len] is the size of program */
+ for (i = 0; i <= prog->len; i++)
+ ctx.offset[i] *= LOONGARCH_INSN_SIZE;
+ bpf_prog_fill_jited_linfo(prog, ctx.offset + 1);
+out_offset:
+ kvfree(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);
+
+ out_offset = -1;
+ return prog;
+}
diff --git a/arch/loongarch/net/bpf_jit.h b/arch/loongarch/net/bpf_jit.h
new file mode 100644
index 0000000..205a935
--- /dev/null
+++ b/arch/loongarch/net/bpf_jit.h
@@ -0,0 +1,282 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * BPF JIT compiler for LoongArch
+ *
+ * Copyright (C) 2022 Loongson Technology Corporation Limited
+ */
+#include <linux/bpf.h>
+#include <linux/filter.h>
+#include <asm/cacheflush.h>
+#include <asm/inst.h>
+
+struct jit_ctx {
+ const struct bpf_prog *prog;
+ unsigned int idx;
+ unsigned int flags;
+ unsigned int epilogue_offset;
+ u32 *offset;
+ union loongarch_instruction *image;
+ u32 stack_size;
+};
+
+struct jit_data {
+ struct bpf_binary_header *header;
+ u8 *image;
+ struct jit_ctx ctx;
+};
+
+#define emit_insn(ctx, func, ...) \
+do { \
+ if (ctx->image != NULL) { \
+ union loongarch_instruction *insn = &ctx->image[ctx->idx]; \
+ emit_##func(insn, ##__VA_ARGS__); \
+ } \
+ ctx->idx++; \
+} while (0)
+
+#define is_signed_imm12(val) signed_imm_check(val, 12)
+#define is_signed_imm14(val) signed_imm_check(val, 14)
+#define is_signed_imm16(val) signed_imm_check(val, 16)
+#define is_signed_imm26(val) signed_imm_check(val, 26)
+#define is_signed_imm32(val) signed_imm_check(val, 32)
+#define is_signed_imm52(val) signed_imm_check(val, 52)
+#define is_unsigned_imm12(val) unsigned_imm_check(val, 12)
+
+static inline int bpf2la_offset(int bpf_insn, int off, const struct jit_ctx *ctx)
+{
+ /* BPF JMP offset is relative to the next instruction */
+ bpf_insn++;
+ /*
+ * Whereas LoongArch branch instructions encode the offset
+ * from the branch itself, so we must subtract 1 from the
+ * instruction offset.
+ */
+ return (ctx->offset[bpf_insn + off] - (ctx->offset[bpf_insn] - 1));
+}
+
+static inline int epilogue_offset(const struct jit_ctx *ctx)
+{
+ int to = ctx->epilogue_offset;
+ int from = ctx->idx;
+
+ return (to - from);
+}
+
+/* Zero-extend 32 bits into 64 bits */
+static inline void emit_zext_32(struct jit_ctx *ctx, enum loongarch_gpr reg, bool is32)
+{
+ if (!is32)
+ return;
+
+ emit_insn(ctx, lu32id, reg, 0);
+}
+
+/* Signed-extend 32 bits into 64 bits */
+static inline void emit_sext_32(struct jit_ctx *ctx, enum loongarch_gpr reg, bool is32)
+{
+ if (!is32)
+ return;
+
+ emit_insn(ctx, addiw, reg, reg, 0);
+}
+
+static inline void move_imm(struct jit_ctx *ctx, enum loongarch_gpr rd, long imm, bool is32)
+{
+ long imm_11_0, imm_31_12, imm_51_32, imm_63_52, imm_51_0, imm_51_31;
+
+ /* or rd, $zero, $zero */
+ if (imm == 0) {
+ emit_insn(ctx, or, rd, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_ZERO);
+ return;
+ }
+
+ /* addiw rd, $zero, imm_11_0 */
+ if (is_signed_imm12(imm)) {
+ emit_insn(ctx, addiw, rd, LOONGARCH_GPR_ZERO, imm);
+ goto zext;
+ }
+
+ /* ori rd, $zero, imm_11_0 */
+ if (is_unsigned_imm12(imm)) {
+ emit_insn(ctx, ori, rd, LOONGARCH_GPR_ZERO, imm);
+ goto zext;
+ }
+
+ /* lu52id rd, $zero, imm_63_52 */
+ imm_63_52 = (imm >> 52) & 0xfff;
+ imm_51_0 = imm & 0xfffffffffffff;
+ if (imm_63_52 != 0 && imm_51_0 == 0) {
+ emit_insn(ctx, lu52id, rd, LOONGARCH_GPR_ZERO, imm_63_52);
+ return;
+ }
+
+ /* lu12iw rd, imm_31_12 */
+ imm_31_12 = (imm >> 12) & 0xfffff;
+ emit_insn(ctx, lu12iw, rd, imm_31_12);
+
+ /* ori rd, rd, imm_11_0 */
+ imm_11_0 = imm & 0xfff;
+ if (imm_11_0 != 0)
+ emit_insn(ctx, ori, rd, rd, imm_11_0);
+
+ if (!is_signed_imm32(imm)) {
+ if (imm_51_0 != 0) {
+ /*
+ * If bit[51:31] is all 0 or all 1,
+ * it means bit[51:32] is sign extended by lu12iw,
+ * no need to call lu32id to do a new filled operation.
+ */
+ imm_51_31 = (imm >> 31) & 0x1fffff;
+ if (imm_51_31 != 0 || imm_51_31 != 0x1fffff) {
+ /* lu32id rd, imm_51_32 */
+ imm_51_32 = (imm >> 32) & 0xfffff;
+ emit_insn(ctx, lu32id, rd, imm_51_32);
+ }
+ }
+
+ /* lu52id rd, rd, imm_63_52 */
+ if (!is_signed_imm52(imm))
+ emit_insn(ctx, lu52id, rd, rd, imm_63_52);
+ }
+
+zext:
+ emit_zext_32(ctx, rd, is32);
+}
+
+static inline void move_reg(struct jit_ctx *ctx, enum loongarch_gpr rd,
+ enum loongarch_gpr rj)
+{
+ emit_insn(ctx, or, rd, rj, LOONGARCH_GPR_ZERO);
+}
+
+static inline int invert_jmp_cond(u8 cond)
+{
+ switch (cond) {
+ case BPF_JEQ:
+ return BPF_JNE;
+ case BPF_JNE:
+ case BPF_JSET:
+ return BPF_JEQ;
+ case BPF_JGT:
+ return BPF_JLE;
+ case BPF_JGE:
+ return BPF_JLT;
+ case BPF_JLT:
+ return BPF_JGE;
+ case BPF_JLE:
+ return BPF_JGT;
+ case BPF_JSGT:
+ return BPF_JSLE;
+ case BPF_JSGE:
+ return BPF_JSLT;
+ case BPF_JSLT:
+ return BPF_JSGE;
+ case BPF_JSLE:
+ return BPF_JSGT;
+ }
+ return -1;
+}
+
+static inline void cond_jmp_offs16(struct jit_ctx *ctx, u8 cond, enum loongarch_gpr rj,
+ enum loongarch_gpr rd, int jmp_offset)
+{
+ switch (cond) {
+ case BPF_JEQ:
+ /* PC += jmp_offset if rj == rd */
+ emit_insn(ctx, beq, rj, rd, jmp_offset);
+ return;
+ case BPF_JNE:
+ case BPF_JSET:
+ /* PC += jmp_offset if rj != rd */
+ emit_insn(ctx, bne, rj, rd, jmp_offset);
+ return;
+ case BPF_JGT:
+ /* PC += jmp_offset if rj > rd (unsigned) */
+ emit_insn(ctx, bltu, rd, rj, jmp_offset);
+ return;
+ case BPF_JLT:
+ /* PC += jmp_offset if rj < rd (unsigned) */
+ emit_insn(ctx, bltu, rj, rd, jmp_offset);
+ return;
+ case BPF_JGE:
+ /* PC += jmp_offset if rj >= rd (unsigned) */
+ emit_insn(ctx, bgeu, rj, rd, jmp_offset);
+ return;
+ case BPF_JLE:
+ /* PC += jmp_offset if rj <= rd (unsigned) */
+ emit_insn(ctx, bgeu, rd, rj, jmp_offset);
+ return;
+ case BPF_JSGT:
+ /* PC += jmp_offset if rj > rd (signed) */
+ emit_insn(ctx, blt, rd, rj, jmp_offset);
+ return;
+ case BPF_JSLT:
+ /* PC += jmp_offset if rj < rd (signed) */
+ emit_insn(ctx, blt, rj, rd, jmp_offset);
+ return;
+ case BPF_JSGE:
+ /* PC += jmp_offset if rj >= rd (signed) */
+ emit_insn(ctx, bge, rj, rd, jmp_offset);
+ return;
+ case BPF_JSLE:
+ /* PC += jmp_offset if rj <= rd (signed) */
+ emit_insn(ctx, bge, rd, rj, jmp_offset);
+ return;
+ }
+}
+
+static inline void cond_jmp_offs26(struct jit_ctx *ctx, u8 cond, enum loongarch_gpr rj,
+ enum loongarch_gpr rd, int jmp_offset)
+{
+ cond = invert_jmp_cond(cond);
+ cond_jmp_offs16(ctx, cond, rj, rd, 2);
+ emit_insn(ctx, b, jmp_offset);
+}
+
+static inline void uncond_jmp_offs26(struct jit_ctx *ctx, int jmp_offset)
+{
+ emit_insn(ctx, b, jmp_offset);
+}
+
+static inline int emit_cond_jmp(struct jit_ctx *ctx, u8 cond, enum loongarch_gpr rj,
+ enum loongarch_gpr rd, int jmp_offset)
+{
+ /*
+ * A large PC-relative jump offset may overflow the immediate field of
+ * the native conditional branch instruction, triggering a conversion
+ * to use an absolute jump instead, this jump sequence is particularly
+ * nasty. For now, use cond_jmp_offs26() directly to keep it simple.
+ * In the future, maybe we can add support for far branching, the branch
+ * relaxation requires more than two passes to converge, the code seems
+ * too complex to understand, not quite sure whether it is necessary and
+ * worth the extra pain. Anyway, just leave it as it is to enhance code
+ * readability now.
+ */
+ if (is_signed_imm26(jmp_offset)) {
+ cond_jmp_offs26(ctx, cond, rj, rd, jmp_offset);
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static inline int emit_uncond_jmp(struct jit_ctx *ctx, int jmp_offset)
+{
+ if (is_signed_imm26(jmp_offset)) {
+ uncond_jmp_offs26(ctx, jmp_offset);
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static inline int emit_tailcall_jmp(struct jit_ctx *ctx, u8 cond, enum loongarch_gpr rj,
+ enum loongarch_gpr rd, int jmp_offset)
+{
+ if (is_signed_imm16(jmp_offset)) {
+ cond_jmp_offs16(ctx, cond, rj, rd, jmp_offset);
+ return 0;
+ }
+
+ return -EINVAL;
+}
--
2.1.0
^ permalink raw reply related [flat|nested] 11+ messages in thread