[PATCH v3 2/3] LoongArch: BPF: Clean up and decouple is32 parameter from move_imm()
From: Tiezhu Yang
Date: Fri Oct 16 2026 - 04:10:54 EST
The current move_imm() relies on the 'is32' parameter for ALU32 and JMP32,
forcing the helper to internally clear the upper 32 bits. However, this is
redundant for 64-bit immediate loads. Furthermore, it is even undesirable
for load/store signed address offset computations.
Clean up move_imm() by removing the 'is32' parameter which allows it to
focus on loading values, while moving the zero-extension logic outward to
the explicit callers. For 64-bit and load-store operations, just drop the
parameter.
This is preparation for later patch, no functional changes.
Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
---
arch/loongarch/net/bpf_jit.c | 102 +++++++++++++++++++----------------
arch/loongarch/net/bpf_jit.h | 7 +--
2 files changed, 58 insertions(+), 51 deletions(-)
diff --git a/arch/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c
index e78eb582c300..77cd96a6f84c 100644
--- a/arch/loongarch/net/bpf_jit.c
+++ b/arch/loongarch/net/bpf_jit.c
@@ -194,7 +194,7 @@ static void build_prologue(struct jit_ctx *ctx)
ctx->stack_size = stack_adjust;
if (ctx->arena_vm_start)
- move_imm(ctx, REG_ARENA, ctx->arena_vm_start, false);
+ move_imm(ctx, REG_ARENA, ctx->arena_vm_start);
}
static void __build_epilogue(struct jit_ctx *ctx, bool is_tail_call)
@@ -339,7 +339,7 @@ static int emit_bpf_tail_call(struct jit_ctx *ctx, int insn)
static void emit_store_stack_imm64(struct jit_ctx *ctx, int reg, int stack_off, u64 imm64)
{
- move_imm(ctx, reg, imm64, false);
+ move_imm(ctx, reg, imm64);
emit_insn(ctx, std, reg, LOONGARCH_GPR_FP, stack_off);
}
@@ -355,7 +355,7 @@ static int emit_atomic_rmw(const struct bpf_insn *insn, struct jit_ctx *ctx)
const s32 imm = insn->imm;
const bool isdw = BPF_SIZE(insn->code) == BPF_DW;
- move_imm(ctx, t1, off, false);
+ move_imm(ctx, t1, off);
emit_insn(ctx, addd, t1, dst, t1);
move_reg(ctx, t3, src);
@@ -528,7 +528,7 @@ static int emit_atomic_ld_st(const struct bpf_insn *insn, struct jit_ctx *ctx)
if (is_signed_imm12(off)) {
emit_insn(ctx, ldbu, dst, src, off);
} else {
- move_imm(ctx, t1, off, false);
+ move_imm(ctx, t1, off);
emit_insn(ctx, ldxbu, dst, src, t1);
}
break;
@@ -536,7 +536,7 @@ static int emit_atomic_ld_st(const struct bpf_insn *insn, struct jit_ctx *ctx)
if (is_signed_imm12(off)) {
emit_insn(ctx, ldhu, dst, src, off);
} else {
- move_imm(ctx, t1, off, false);
+ move_imm(ctx, t1, off);
emit_insn(ctx, ldxhu, dst, src, t1);
}
break;
@@ -544,7 +544,7 @@ static int emit_atomic_ld_st(const struct bpf_insn *insn, struct jit_ctx *ctx)
if (is_signed_imm12(off)) {
emit_insn(ctx, ldwu, dst, src, off);
} else {
- move_imm(ctx, t1, off, false);
+ move_imm(ctx, t1, off);
emit_insn(ctx, ldxwu, dst, src, t1);
}
break;
@@ -552,7 +552,7 @@ static int emit_atomic_ld_st(const struct bpf_insn *insn, struct jit_ctx *ctx)
if (is_signed_imm12(off)) {
emit_insn(ctx, ldd, dst, src, off);
} else {
- move_imm(ctx, t1, off, false);
+ move_imm(ctx, t1, off);
emit_insn(ctx, ldxd, dst, src, t1);
}
break;
@@ -567,7 +567,7 @@ static int emit_atomic_ld_st(const struct bpf_insn *insn, struct jit_ctx *ctx)
if (is_signed_imm12(off)) {
emit_insn(ctx, stb, src, dst, off);
} else {
- move_imm(ctx, t1, off, false);
+ move_imm(ctx, t1, off);
emit_insn(ctx, stxb, src, dst, t1);
}
break;
@@ -575,7 +575,7 @@ static int emit_atomic_ld_st(const struct bpf_insn *insn, struct jit_ctx *ctx)
if (is_signed_imm12(off)) {
emit_insn(ctx, sth, src, dst, off);
} else {
- move_imm(ctx, t1, off, false);
+ move_imm(ctx, t1, off);
emit_insn(ctx, stxh, src, dst, t1);
}
break;
@@ -583,7 +583,7 @@ static int emit_atomic_ld_st(const struct bpf_insn *insn, struct jit_ctx *ctx)
if (is_signed_imm12(off)) {
emit_insn(ctx, stw, src, dst, off);
} else {
- move_imm(ctx, t1, off, false);
+ move_imm(ctx, t1, off);
emit_insn(ctx, stxw, src, dst, t1);
}
break;
@@ -591,7 +591,7 @@ static int emit_atomic_ld_st(const struct bpf_insn *insn, struct jit_ctx *ctx)
if (is_signed_imm12(off)) {
emit_insn(ctx, std, src, dst, off);
} else {
- move_imm(ctx, t1, off, false);
+ move_imm(ctx, t1, off);
emit_insn(ctx, stxd, src, dst, t1);
}
break;
@@ -716,7 +716,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
if (insn_is_cast_user(insn)) {
move_reg(ctx, t1, src);
emit_zext_32(ctx, t1, true);
- move_imm(ctx, dst, (ctx->user_vm_start >> 32) << 32, false);
+ move_imm(ctx, dst, (ctx->user_vm_start >> 32) << 32);
emit_insn(ctx, beq, t1, LOONGARCH_GPR_ZERO, 2);
emit_insn(ctx, or, t1, dst, t1);
move_reg(ctx, dst, t1);
@@ -753,7 +753,8 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
/* dst = imm */
case BPF_ALU | BPF_MOV | BPF_K:
case BPF_ALU64 | BPF_MOV | BPF_K:
- move_imm(ctx, dst, imm, is32);
+ move_imm(ctx, dst, imm);
+ emit_zext_32(ctx, dst, is32);
break;
/* dst = dst + src */
@@ -769,7 +770,8 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
if (is_signed_imm12(imm)) {
emit_insn(ctx, addid, dst, dst, imm);
} else {
- move_imm(ctx, t1, imm, is32);
+ move_imm(ctx, t1, imm);
+ emit_zext_32(ctx, t1, is32);
emit_insn(ctx, addd, dst, dst, t1);
}
emit_zext_32(ctx, dst, is32);
@@ -788,7 +790,8 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
if (is_signed_imm12(-imm)) {
emit_insn(ctx, addid, dst, dst, -imm);
} else {
- move_imm(ctx, t1, imm, is32);
+ move_imm(ctx, t1, imm);
+ emit_zext_32(ctx, t1, is32);
emit_insn(ctx, subd, dst, dst, t1);
}
emit_zext_32(ctx, dst, is32);
@@ -804,7 +807,8 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
/* dst = dst * imm */
case BPF_ALU | BPF_MUL | BPF_K:
case BPF_ALU64 | BPF_MUL | BPF_K:
- move_imm(ctx, t1, imm, is32);
+ move_imm(ctx, t1, imm);
+ emit_zext_32(ctx, t1, is32);
emit_insn(ctx, muld, dst, dst, t1);
emit_zext_32(ctx, dst, is32);
break;
@@ -831,12 +835,13 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
case BPF_ALU | BPF_DIV | BPF_K:
case BPF_ALU64 | BPF_DIV | BPF_K:
if (!off) {
- move_imm(ctx, t1, imm, is32);
+ move_imm(ctx, t1, imm);
+ emit_zext_32(ctx, t1, is32);
emit_zext_32(ctx, dst, is32);
emit_insn(ctx, divdu, dst, dst, t1);
emit_zext_32(ctx, dst, is32);
} else {
- move_imm(ctx, t1, imm, false);
+ move_imm(ctx, t1, imm);
emit_sext_32(ctx, t1, is32);
emit_sext_32(ctx, dst, is32);
emit_insn(ctx, divd, dst, dst, t1);
@@ -866,12 +871,13 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
case BPF_ALU | BPF_MOD | BPF_K:
case BPF_ALU64 | BPF_MOD | BPF_K:
if (!off) {
- move_imm(ctx, t1, imm, is32);
+ move_imm(ctx, t1, imm);
+ emit_zext_32(ctx, t1, is32);
emit_zext_32(ctx, dst, is32);
emit_insn(ctx, moddu, dst, dst, t1);
emit_zext_32(ctx, dst, is32);
} else {
- move_imm(ctx, t1, imm, false);
+ move_imm(ctx, t1, imm);
emit_sext_32(ctx, t1, is32);
emit_sext_32(ctx, dst, is32);
emit_insn(ctx, modd, dst, dst, t1);
@@ -899,7 +905,8 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
if (is_unsigned_imm12(imm)) {
emit_insn(ctx, andi, dst, dst, imm);
} else {
- move_imm(ctx, t1, imm, is32);
+ move_imm(ctx, t1, imm);
+ emit_zext_32(ctx, t1, is32);
emit_insn(ctx, and, dst, dst, t1);
}
emit_zext_32(ctx, dst, is32);
@@ -918,7 +925,8 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
if (is_unsigned_imm12(imm)) {
emit_insn(ctx, ori, dst, dst, imm);
} else {
- move_imm(ctx, t1, imm, is32);
+ move_imm(ctx, t1, imm);
+ emit_zext_32(ctx, t1, is32);
emit_insn(ctx, or, dst, dst, t1);
}
emit_zext_32(ctx, dst, is32);
@@ -937,7 +945,8 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
if (is_unsigned_imm12(imm)) {
emit_insn(ctx, xori, dst, dst, imm);
} else {
- move_imm(ctx, t1, imm, is32);
+ move_imm(ctx, t1, imm);
+ emit_zext_32(ctx, t1, is32);
emit_insn(ctx, xor, dst, dst, t1);
}
emit_zext_32(ctx, dst, is32);
@@ -1097,7 +1106,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
case BPF_JMP32 | BPF_JSLE | BPF_K:
jmp_offset = bpf2la_offset(i, off, ctx);
if (imm) {
- move_imm(ctx, t1, imm, false);
+ move_imm(ctx, t1, imm);
tm = t1;
} else {
/* If imm is 0, simply use zero register. */
@@ -1129,7 +1138,8 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
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);
+ move_imm(ctx, t1, imm);
+ emit_zext_32(ctx, t1, 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)
@@ -1227,7 +1237,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
if (bpf_pseudo_func(insn))
move_addr(ctx, dst, imm64);
else
- move_imm(ctx, dst, imm64, is32);
+ move_imm(ctx, dst, imm64);
return 1;
}
@@ -1268,7 +1278,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
else
emit_insn(ctx, ldbu, dst, src, off);
} else {
- move_imm(ctx, t1, off, is32);
+ move_imm(ctx, t1, off);
if (sign_extend)
emit_insn(ctx, ldxb, dst, src, t1);
else
@@ -1282,7 +1292,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
else
emit_insn(ctx, ldhu, dst, src, off);
} else {
- move_imm(ctx, t1, off, is32);
+ move_imm(ctx, t1, off);
if (sign_extend)
emit_insn(ctx, ldxh, dst, src, t1);
else
@@ -1296,7 +1306,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
else
emit_insn(ctx, ldwu, dst, src, off);
} else {
- move_imm(ctx, t1, off, is32);
+ move_imm(ctx, t1, off);
if (sign_extend)
emit_insn(ctx, ldxw, dst, src, t1);
else
@@ -1304,7 +1314,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
}
break;
case BPF_DW:
- move_imm(ctx, t1, off, is32);
+ move_imm(ctx, t1, off);
emit_insn(ctx, ldxd, dst, src, t1);
break;
}
@@ -1331,42 +1341,42 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
switch (BPF_SIZE(code)) {
case BPF_B:
- move_imm(ctx, t1, imm, is32);
+ move_imm(ctx, t1, imm);
if (is_signed_imm12(off)) {
emit_insn(ctx, stb, t1, dst, off);
} else {
- move_imm(ctx, t2, off, is32);
+ move_imm(ctx, t2, off);
emit_insn(ctx, stxb, t1, dst, t2);
}
break;
case BPF_H:
- move_imm(ctx, t1, imm, is32);
+ move_imm(ctx, t1, imm);
if (is_signed_imm12(off)) {
emit_insn(ctx, sth, t1, dst, off);
} else {
- move_imm(ctx, t2, off, is32);
+ move_imm(ctx, t2, off);
emit_insn(ctx, stxh, t1, dst, t2);
}
break;
case BPF_W:
- move_imm(ctx, t1, imm, is32);
+ move_imm(ctx, t1, imm);
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);
+ move_imm(ctx, t2, off);
emit_insn(ctx, stxw, t1, dst, t2);
}
break;
case BPF_DW:
- move_imm(ctx, t1, imm, is32);
+ move_imm(ctx, t1, imm);
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);
+ move_imm(ctx, t2, off);
emit_insn(ctx, stxd, t1, dst, t2);
}
break;
@@ -1397,7 +1407,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
if (is_signed_imm12(off)) {
emit_insn(ctx, stb, src, dst, off);
} else {
- move_imm(ctx, t1, off, is32);
+ move_imm(ctx, t1, off);
emit_insn(ctx, stxb, src, dst, t1);
}
break;
@@ -1405,7 +1415,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
if (is_signed_imm12(off)) {
emit_insn(ctx, sth, src, dst, off);
} else {
- move_imm(ctx, t1, off, is32);
+ move_imm(ctx, t1, off);
emit_insn(ctx, stxh, src, dst, t1);
}
break;
@@ -1415,7 +1425,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
} else if (is_signed_imm14(off)) {
emit_insn(ctx, stptrw, src, dst, off);
} else {
- move_imm(ctx, t1, off, is32);
+ move_imm(ctx, t1, off);
emit_insn(ctx, stxw, src, dst, t1);
}
break;
@@ -1425,7 +1435,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
} else if (is_signed_imm14(off)) {
emit_insn(ctx, stptrd, src, dst, off);
} else {
- move_imm(ctx, t1, off, is32);
+ move_imm(ctx, t1, off);
emit_insn(ctx, stxd, src, dst, t1);
}
break;
@@ -1537,7 +1547,7 @@ static int emit_jump_and_link(struct jit_ctx *ctx, u8 rd, u64 target)
return -EFAULT;
}
- move_imm(ctx, LOONGARCH_GPR_T1, target, false);
+ move_imm(ctx, LOONGARCH_GPR_T1, target);
emit_insn(ctx, jirl, rd, LOONGARCH_GPR_T1, 0);
return 0;
@@ -1734,7 +1744,7 @@ static int invoke_bpf_prog(struct jit_ctx *ctx, struct bpf_tramp_image *im,
emit_insn(ctx, std, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_FP, -run_ctx_off + cookie_off);
/* arg1: prog */
- move_imm(ctx, LOONGARCH_GPR_A0, (const s64)p, false);
+ move_imm(ctx, LOONGARCH_GPR_A0, (const s64)p);
/* arg2: &run_ctx */
emit_insn(ctx, addid, LOONGARCH_GPR_A1, LOONGARCH_GPR_FP, -run_ctx_off);
ret = emit_call(ctx, (const u64)bpf_trampoline_enter(p));
@@ -1755,7 +1765,7 @@ static int invoke_bpf_prog(struct jit_ctx *ctx, struct bpf_tramp_image *im,
/* arg1: &args_off */
emit_insn(ctx, addid, LOONGARCH_GPR_A0, LOONGARCH_GPR_FP, -args_off);
if (!p->jited)
- move_imm(ctx, LOONGARCH_GPR_A1, (const s64)p->insnsi, false);
+ move_imm(ctx, LOONGARCH_GPR_A1, (const s64)p->insnsi);
ret = emit_call(ctx, (const u64)p->bpf_func);
if (ret)
return ret;
@@ -1772,7 +1782,7 @@ static int invoke_bpf_prog(struct jit_ctx *ctx, struct bpf_tramp_image *im,
}
/* arg1: prog */
- move_imm(ctx, LOONGARCH_GPR_A0, (const s64)p, false);
+ move_imm(ctx, LOONGARCH_GPR_A0, (const s64)p);
/* arg2: prog start time */
move_reg(ctx, LOONGARCH_GPR_A1, LOONGARCH_GPR_S1);
/* arg3: &run_ctx */
diff --git a/arch/loongarch/net/bpf_jit.h b/arch/loongarch/net/bpf_jit.h
index bb58c42c2f2a..57a98f8a055b 100644
--- a/arch/loongarch/net/bpf_jit.h
+++ b/arch/loongarch/net/bpf_jit.h
@@ -137,7 +137,7 @@ static inline void move_addr(struct jit_ctx *ctx, enum loongarch_gpr rd, u64 add
emit_insn(ctx, lu52id, rd, rd, imm_63_52);
}
-static inline void move_imm(struct jit_ctx *ctx, enum loongarch_gpr rd, long imm, bool is32)
+static inline void move_imm(struct jit_ctx *ctx, enum loongarch_gpr rd, long imm)
{
long imm_11_0, imm_31_12, imm_51_32, imm_63_52, imm_51_0, imm_51_31;
@@ -150,7 +150,7 @@ static inline void move_imm(struct jit_ctx *ctx, enum loongarch_gpr rd, long imm
/* addiw rd, $zero, imm_11_0 */
if (is_signed_imm12(imm)) {
emit_insn(ctx, addiw, rd, LOONGARCH_GPR_ZERO, imm);
- goto zext;
+ return;
}
/* ori rd, $zero, imm_11_0 */
@@ -195,9 +195,6 @@ static inline void move_imm(struct jit_ctx *ctx, enum loongarch_gpr rd, long imm
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,
--
2.42.0