diff options
| author |   Ilya Leoshkevich <iii@linux.ibm.com> | 2019-11-18 19:03:38 +0100 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2019-11-18 19:51:16 -0800 |
| commit | 451e448ff4bb137da3d4b8b26a8260a2ff66869a (patch) | |
| tree | e1829a7bf05560eb28a49d20b52b6b8def0ae61d /arch/s390 | |
| parent | s390/bpf: Load literal pool register using larl (diff) | |
| download | linux-dev-451e448ff4bb137da3d4b8b26a8260a2ff66869a.tar.xz linux-dev-451e448ff4bb137da3d4b8b26a8260a2ff66869a.zip | |
s390/bpf: Use lgrl instead of lg where possible
lg and lgrl have the same performance characteristics, but the former
requires a base register and is subject to long displacement range
limits, while the latter does not. Therefore, lgrl is totally superior
to lg and should be used instead whenever possible.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191118180340.68373-5-iii@linux.ibm.com
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/net/bpf_jit_comp.c | 32 |
1 files changed, 20 insertions, 12 deletions
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index 964a09fd10f1..6b3f85e4c5b0 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -287,28 +287,38 @@ static inline void reg_set_seen(struct bpf_jit *jit, u32 b1) REG_SET_SEEN(b1); \ }) -#define EMIT_CONST_U32(val) \ +#define _EMIT_CONST_U32(val) \ ({ \ unsigned int ret; \ - ret = jit->lit32 - jit->base_ip; \ - jit->seen |= SEEN_LITERAL; \ + ret = jit->lit32; \ if (jit->prg_buf) \ *(u32 *)(jit->prg_buf + jit->lit32) = (u32)(val);\ jit->lit32 += 4; \ ret; \ }) -#define EMIT_CONST_U64(val) \ +#define EMIT_CONST_U32(val) \ ({ \ - unsigned int ret; \ - ret = jit->lit64 - jit->base_ip; \ jit->seen |= SEEN_LITERAL; \ + _EMIT_CONST_U32(val) - jit->base_ip; \ +}) + +#define _EMIT_CONST_U64(val) \ +({ \ + unsigned int ret; \ + ret = jit->lit64; \ if (jit->prg_buf) \ *(u64 *)(jit->prg_buf + jit->lit64) = (u64)(val);\ jit->lit64 += 8; \ ret; \ }) +#define EMIT_CONST_U64(val) \ +({ \ + jit->seen |= SEEN_LITERAL; \ + _EMIT_CONST_U64(val) - jit->base_ip; \ +}) + #define EMIT_ZERO(b1) \ ({ \ if (!fp->aux->verifier_zext) { \ @@ -612,9 +622,8 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, u64 imm64; imm64 = (u64)(u32) insn[0].imm | ((u64)(u32) insn[1].imm) << 32; - /* lg %dst,<d(imm)>(%l) */ - EMIT6_DISP_LH(0xe3000000, 0x0004, dst_reg, REG_0, REG_L, - EMIT_CONST_U64(imm64)); + /* lgrl %dst,imm */ + EMIT6_PCREL_RILB(0xc4080000, dst_reg, _EMIT_CONST_U64(imm64)); insn_count = 2; break; } @@ -1086,9 +1095,8 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, REG_SET_SEEN(BPF_REG_5); jit->seen |= SEEN_FUNC; - /* lg %w1,<d(imm)>(%l) */ - EMIT6_DISP_LH(0xe3000000, 0x0004, REG_W1, REG_0, REG_L, - EMIT_CONST_U64(func)); + /* lgrl %w1,func */ + EMIT6_PCREL_RILB(0xc4080000, REG_W1, _EMIT_CONST_U64(func)); if (__is_defined(CC_USING_EXPOLINE) && !nospec_disable) { /* brasl %r14,__s390_indirect_jump_r1 */ EMIT6_PCREL_RILB(0xc0050000, REG_14, jit->r1_thunk_ip); |