From 9c662cad2fb66ff3a44b1d4f545bf496bf67ab10 Mon Sep 17 00:00:00 2001 From: Philippe Bergheaud Date: Tue, 24 Sep 2013 14:13:35 +0200 Subject: [PATCH] powerpc/bpf: BPF JIT compiler for 64-bit Little Endian This enables the Berkeley Packet Filter JIT compiler for the PowerPC running in 64bit Little Endian. Signed-off-by: Philippe Bergheaud Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/ppc-opcode.h | 1 + arch/powerpc/net/bpf_jit.h | 10 ++++++++++ arch/powerpc/net/bpf_jit_64.S | 9 ++++++++- arch/powerpc/net/bpf_jit_comp.c | 17 ++--------------- 4 files changed, 21 insertions(+), 16 deletions(-) diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h index 442edee..99f8790 100644 --- a/arch/powerpc/include/asm/ppc-opcode.h +++ b/arch/powerpc/include/asm/ppc-opcode.h @@ -203,6 +203,7 @@ /* Misc instructions for BPF compiler */ #define PPC_INST_LD 0xe8000000 #define PPC_INST_LHZ 0xa0000000 +#define PPC_INST_LHBRX 0x7c00062c #define PPC_INST_LWZ 0x80000000 #define PPC_INST_STD 0xf8000000 #define PPC_INST_STDU 0xf8000001 diff --git a/arch/powerpc/net/bpf_jit.h b/arch/powerpc/net/bpf_jit.h index 8a5dfaf..0baf2b8 100644 --- a/arch/powerpc/net/bpf_jit.h +++ b/arch/powerpc/net/bpf_jit.h @@ -92,6 +92,8 @@ DECLARE_LOAD_FUNC(sk_load_byte_msh); ___PPC_RA(base) | IMM_L(i)) #define PPC_LHZ(r, base, i) EMIT(PPC_INST_LHZ | ___PPC_RT(r) | \ ___PPC_RA(base) | IMM_L(i)) +#define PPC_LHBRX(r, base, b) EMIT(PPC_INST_LHBRX | ___PPC_RT(r) | \ + ___PPC_RA(base) | ___PPC_RB(b)) /* Convenience helpers for the above with 'far' offsets: */ #define PPC_LD_OFFS(r, base, i) do { if ((i) < 32768) PPC_LD(r, base, i); \ else { PPC_ADDIS(r, base, IMM_HA(i)); \ @@ -186,6 +188,14 @@ DECLARE_LOAD_FUNC(sk_load_byte_msh); PPC_ORI(d, d, (uintptr_t)(i) & 0xffff); \ } } while (0); +#define PPC_LHBRX_OFFS(r, base, i) \ + do { PPC_LI32(r, i); PPC_LHBRX(r, r, base); } while(0) +#ifdef __LITTLE_ENDIAN__ +#define PPC_NTOHS_OFFS(r, base, i) PPC_LHBRX_OFFS(r, base, i) +#else +#define PPC_NTOHS_OFFS(r, base, i) PPC_LHZ_OFFS(r, base, i) +#endif + static inline bool is_nearbranch(int offset) { return (offset < 32768) && (offset >= -32768); diff --git a/arch/powerpc/net/bpf_jit_64.S b/arch/powerpc/net/bpf_jit_64.S index 7d3a3b5..e76eba7 100644 --- a/arch/powerpc/net/bpf_jit_64.S +++ b/arch/powerpc/net/bpf_jit_64.S @@ -43,8 +43,11 @@ sk_load_word_positive_offset: cmpd r_scratch1, r_addr blt bpf_slow_path_word /* Nope, just hitting the header. cr0 here is eq or gt! */ +#ifdef __LITTLE_ENDIAN__ + lwbrx r_A, r_D, r_addr +#else lwzx r_A, r_D, r_addr - /* When big endian we don't need to byteswap. */ +#endif blr /* Return success, cr0 != LT */ .globl sk_load_half @@ -56,7 +59,11 @@ sk_load_half_positive_offset: subi r_scratch1, r_HL, 2 cmpd r_scratch1, r_addr blt bpf_slow_path_half +#ifdef __LITTLE_ENDIAN__ + lhbrx r_A, r_D, r_addr +#else lhzx r_A, r_D, r_addr +#endif blr .globl sk_load_byte diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c index bf56e33..81cd6c7 100644 --- a/arch/powerpc/net/bpf_jit_comp.c +++ b/arch/powerpc/net/bpf_jit_comp.c @@ -17,14 +17,8 @@ #include "bpf_jit.h" -#ifndef __BIG_ENDIAN -/* There are endianness assumptions herein. */ -#error "Little-endian PPC not supported in BPF compiler" -#endif - int bpf_jit_enable __read_mostly; - static inline void bpf_flush_icache(void *start, void *end) { smp_wmb(); @@ -346,18 +340,11 @@ static int bpf_jit_build_body(struct sk_filter *fp, u32 *image, break; /*** Ancillary info loads ***/ - - /* None of the BPF_S_ANC* codes appear to be passed by - * sk_chk_filter(). The interpreter and the x86 BPF - * compiler implement them so we do too -- they may be - * planted in future. - */ case BPF_S_ANC_PROTOCOL: /* A = ntohs(skb->protocol); */ BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, protocol) != 2); - PPC_LHZ_OFFS(r_A, r_skb, offsetof(struct sk_buff, - protocol)); - /* ntohs is a NOP with BE loads. */ + PPC_NTOHS_OFFS(r_A, r_skb, offsetof(struct sk_buff, + protocol)); break; case BPF_S_ANC_IFINDEX: PPC_LD_OFFS(r_scratch1, r_skb, offsetof(struct sk_buff, -- 2.7.4