diff options
| author | Russell King <rmk+kernel@armlinux.org.uk> | 2018-07-11 11:32:17 +0200 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2018-07-12 20:45:23 +0200 |
| commit | 2b6958ef1151452cb2160fde75a5c5382b512c34 (patch) | |
| tree | 42ca3eed1a541f1ae1eb283f7cd36d6e122524e1 /arch | |
| parent | ARM: net: bpf: use immediate forms of instructions where possible (diff) | |
| download | linux-2b6958ef1151452cb2160fde75a5c5382b512c34.tar.xz linux-2b6958ef1151452cb2160fde75a5c5382b512c34.zip | |
ARM: net: bpf: use ldr instructions with shifted rm register
Rather than pre-shifting the rm register for the ldr in the tail call,
shift it in the load instruction. This eliminates one unnecessary
instruction.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/net/bpf_jit_32.c | 3 | ||||
| -rw-r--r-- | arch/arm/net/bpf_jit_32.h | 4 |
2 files changed, 5 insertions, 2 deletions
diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c index 645653e1931e..e22dc828420c 100644 --- a/arch/arm/net/bpf_jit_32.c +++ b/arch/arm/net/bpf_jit_32.c @@ -1096,8 +1096,7 @@ static int emit_bpf_tail_call(struct jit_ctx *ctx) r_array = arm_bpf_get_reg32(r2[1], tmp2[1], ctx); emit(ARM_ADD_I(tmp[1], r_array, off), ctx); r_index = arm_bpf_get_reg32(r3[1], tmp2[1], ctx); - emit(ARM_MOV_SI(tmp[0], r_index, SRTYPE_ASL, 2), ctx); - emit(ARM_LDR_R(tmp[1], tmp[1], tmp[0]), ctx); + emit(ARM_LDR_R_SI(tmp[1], tmp[1], r_index, SRTYPE_ASL, 2), ctx); emit(ARM_CMP_I(tmp[1], 0), ctx); _emit(ARM_COND_EQ, ARM_B(jmp_offset), ctx); diff --git a/arch/arm/net/bpf_jit_32.h b/arch/arm/net/bpf_jit_32.h index dee8a76fb0bc..e541a7a6139a 100644 --- a/arch/arm/net/bpf_jit_32.h +++ b/arch/arm/net/bpf_jit_32.h @@ -188,6 +188,10 @@ #define ARM_LDR_R(rt, rn, rm) (ARM_INST_LDR_R | ARM_INST_LDST__U \ | (rt) << 12 | (rn) << 16 \ | (rm)) +#define ARM_LDR_R_SI(rt, rn, rm, type, imm) \ + (ARM_INST_LDR_R | ARM_INST_LDST__U \ + | (rt) << 12 | (rn) << 16 \ + | (imm) << 7 | (type) << 5 | (rm)) #define ARM_LDRB_R(rt, rn, rm) (ARM_INST_LDRB_R | ARM_INST_LDST__U \ | (rt) << 12 | (rn) << 16 \ | (rm)) |