diff options
author | Markos Chandras <markos.chandras@imgtec.com> | 2015-06-04 11:56:11 +0100 |
---|---|---|
committer | Ralf Baechle <ralf@linux-mips.org> | 2015-06-21 21:54:22 +0200 |
commit | ad152bd69823fbca63fff9ac3fbe448251eef11b (patch) | |
tree | 57791f7eb566c2e0ab21456c287d141d2d8ec3d0 | |
parent | de5792a4ec8abb88ceee83b403b549255146c867 (diff) | |
download | linux-ad152bd69823fbca63fff9ac3fbe448251eef11b.tar.gz linux-ad152bd69823fbca63fff9ac3fbe448251eef11b.tar.bz2 linux-ad152bd69823fbca63fff9ac3fbe448251eef11b.zip |
MIPS: BPF: Free up some callee-saved registers
Move the two scratch registers from s0 and s1 to t4 and t5 in order
to free up some callee-saved registers. We will use these callee-saved
registers to store some permanent data on them in a subsequent patch.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: netdev@vger.kernel.org
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/10525/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
-rw-r--r-- | arch/mips/net/bpf_jit.c | 35 | ||||
-rw-r--r-- | arch/mips/net/bpf_jit.h | 2 |
2 files changed, 17 insertions, 20 deletions
diff --git a/arch/mips/net/bpf_jit.c b/arch/mips/net/bpf_jit.c index e23fdf2a9c80..73a473c5bdd6 100644 --- a/arch/mips/net/bpf_jit.c +++ b/arch/mips/net/bpf_jit.c @@ -29,9 +29,6 @@ /* ABI * - * s0 1st scratch register - * s1 2nd scratch register - * s2 offset register * s3 BPF register A * s4 BPF register X * s5 *skb @@ -88,13 +85,13 @@ * any of the $s0-$s6 registers will only be preserved if * they are going to actually be used. */ -#define r_s0 MIPS_R_S0 /* scratch reg 1 */ -#define r_s1 MIPS_R_S1 /* scratch reg 2 */ #define r_off MIPS_R_S2 #define r_A MIPS_R_S3 #define r_X MIPS_R_S4 #define r_skb MIPS_R_S5 #define r_M MIPS_R_S6 +#define r_s0 MIPS_R_T4 /* scratch reg 1 */ +#define r_s1 MIPS_R_T5 /* scratch reg 2 */ #define r_tmp_imm MIPS_R_T6 /* No need to preserve this */ #define r_tmp MIPS_R_T7 /* No need to preserve this */ #define r_zero MIPS_R_ZERO @@ -108,8 +105,6 @@ #define SEEN_SREG_SFT (BPF_MEMWORDS + 1) #define SEEN_SREG_BASE (1 << SEEN_SREG_SFT) #define SEEN_SREG(x) (SEEN_SREG_BASE << (x)) -#define SEEN_S0 SEEN_SREG(0) -#define SEEN_S1 SEEN_SREG(1) #define SEEN_OFF SEEN_SREG(2) #define SEEN_A SEEN_SREG(3) #define SEEN_X SEEN_SREG(4) @@ -813,7 +808,7 @@ load_common: b_imm(prog->len, ctx), ctx); emit_reg_move(r_ret, r_zero, ctx); - ctx->flags |= SEEN_CALL | SEEN_OFF | SEEN_S0 | + ctx->flags |= SEEN_CALL | SEEN_OFF | SEEN_SKB | SEEN_A; emit_load_func(r_s0, (ptr)load_func[load_order], @@ -879,7 +874,7 @@ load_ind: return -ENOTSUPP; /* X <- 4 * (P[k:1] & 0xf) */ - ctx->flags |= SEEN_X | SEEN_CALL | SEEN_S0 | SEEN_SKB; + ctx->flags |= SEEN_X | SEEN_CALL | SEEN_SKB; /* Load offset to a1 */ emit_load_func(r_s0, (ptr)jit_get_skb_b, ctx); /* @@ -943,7 +938,7 @@ load_ind: case BPF_ALU | BPF_MUL | BPF_K: /* A *= K */ /* Load K to scratch register before MUL */ - ctx->flags |= SEEN_A | SEEN_S0; + ctx->flags |= SEEN_A; emit_load_imm(r_s0, k, ctx); emit_mul(r_A, r_A, r_s0, ctx); break; @@ -961,7 +956,7 @@ load_ind: emit_srl(r_A, r_A, k, ctx); break; } - ctx->flags |= SEEN_A | SEEN_S0; + ctx->flags |= SEEN_A; emit_load_imm(r_s0, k, ctx); emit_div(r_A, r_s0, ctx); break; @@ -971,7 +966,7 @@ load_ind: ctx->flags |= SEEN_A; emit_jit_reg_move(r_A, r_zero, ctx); } else { - ctx->flags |= SEEN_A | SEEN_S0; + ctx->flags |= SEEN_A; emit_load_imm(r_s0, k, ctx); emit_mod(r_A, r_s0, ctx); } @@ -1085,10 +1080,10 @@ jmp_cmp: if ((condt & MIPS_COND_GE) || (condt & MIPS_COND_GT)) { if (condt & MIPS_COND_K) { /* K */ - ctx->flags |= SEEN_S0 | SEEN_A; + ctx->flags |= SEEN_A; emit_sltiu(r_s0, r_A, k, ctx); } else { /* X */ - ctx->flags |= SEEN_S0 | SEEN_A | + ctx->flags |= SEEN_A | SEEN_X; emit_sltu(r_s0, r_A, r_X, ctx); } @@ -1100,7 +1095,7 @@ jmp_cmp: /* A > (K|X) ? scratch = 0 */ if (condt & MIPS_COND_GT) { /* Checking for equality */ - ctx->flags |= SEEN_S0 | SEEN_A | SEEN_X; + ctx->flags |= SEEN_A | SEEN_X; if (condt & MIPS_COND_K) emit_load_imm(r_s0, k, ctx); else @@ -1123,7 +1118,7 @@ jmp_cmp: } else { /* A == K|X */ if (condt & MIPS_COND_K) { /* K */ - ctx->flags |= SEEN_S0 | SEEN_A; + ctx->flags |= SEEN_A; emit_load_imm(r_s0, k, ctx); /* jump true */ b_off = b_imm(i + inst->jt + 1, ctx); @@ -1153,7 +1148,7 @@ jmp_cmp: } break; case BPF_JMP | BPF_JSET | BPF_K: - ctx->flags |= SEEN_S0 | SEEN_S1 | SEEN_A; + ctx->flags |= SEEN_A; /* pc += (A & K) ? pc -> jt : pc -> jf */ emit_load_imm(r_s1, k, ctx); emit_and(r_s0, r_A, r_s1, ctx); @@ -1167,7 +1162,7 @@ jmp_cmp: emit_nop(ctx); break; case BPF_JMP | BPF_JSET | BPF_X: - ctx->flags |= SEEN_S0 | SEEN_X | SEEN_A; + ctx->flags |= SEEN_X | SEEN_A; /* pc += (A & X) ? pc -> jt : pc -> jf */ emit_and(r_s0, r_A, r_X, ctx); /* jump true */ @@ -1251,7 +1246,7 @@ jmp_cmp: break; case BPF_ANC | SKF_AD_IFINDEX: /* A = skb->dev->ifindex */ - ctx->flags |= SEEN_SKB | SEEN_A | SEEN_S0; + ctx->flags |= SEEN_SKB | SEEN_A; off = offsetof(struct sk_buff, dev); /* Load *dev pointer */ emit_load_ptr(r_s0, r_skb, off, ctx); @@ -1278,7 +1273,7 @@ jmp_cmp: break; case BPF_ANC | SKF_AD_VLAN_TAG: case BPF_ANC | SKF_AD_VLAN_TAG_PRESENT: - ctx->flags |= SEEN_SKB | SEEN_S0 | SEEN_A; + ctx->flags |= SEEN_SKB | SEEN_A; BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_tci) != 2); off = offsetof(struct sk_buff, vlan_tci); diff --git a/arch/mips/net/bpf_jit.h b/arch/mips/net/bpf_jit.h index 3a5751b4335a..f9b5a4d3dbf4 100644 --- a/arch/mips/net/bpf_jit.h +++ b/arch/mips/net/bpf_jit.h @@ -18,6 +18,8 @@ #define MIPS_R_V1 3 #define MIPS_R_A0 4 #define MIPS_R_A1 5 +#define MIPS_R_T4 12 +#define MIPS_R_T5 13 #define MIPS_R_T6 14 #define MIPS_R_T7 15 #define MIPS_R_S0 16 |