/* bpf_jit.h: BPF JIT compiler for PPC64 * * Copyright 2011 Matt Evans , IBM Corporation * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; version 2 * of the License. */ #ifndef _BPF_JIT_H #define _BPF_JIT_H #define BPF_PPC_STACK_LOCALS 32 #define BPF_PPC_STACK_BASIC (48+64) #define BPF_PPC_STACK_SAVE (18*8) #define BPF_PPC_STACKFRAME (BPF_PPC_STACK_BASIC+BPF_PPC_STACK_LOCALS+ \ BPF_PPC_STACK_SAVE) #define BPF_PPC_SLOWPATH_FRAME (48+64) /* * Generated code register usage: * * As normal PPC C ABI (e.g. r1=sp, r2=TOC), with: * * skb r3 (Entry parameter) * A register r4 * X register r5 * addr param r6 * r7-r10 scratch * skb->data r14 * skb headlen r15 (skb->len - skb->data_len) * m[0] r16 * m[...] ... * m[15] r31 */ #define r_skb 3 #define r_ret 3 #define r_A 4 #define r_X 5 #define r_addr 6 #define r_scratch1 7 #define r_D 14 #define r_HL 15 #define r_M 16 #ifndef __ASSEMBLY__ /* * Assembly helpers from arch/powerpc/net/bpf_jit.S: */ #define DECLARE_LOAD_FUNC(func) \ extern u8 func[], func##_negative_offset[], func##_positive_offset[] DECLARE_LOAD_FUNC(sk_load_word); DECLARE_LOAD_FUNC(sk_load_half); DECLARE_LOAD_FUNC(sk_load_byte); DECLARE_LOAD_FUNC(sk_load_byte_msh); #define FUNCTION_DESCR_SIZE 24 /* * 16-bit immediate helper macros: HA() is for use with sign-extending instrs * (e.g. LD, ADDI). If the bottom 16 bits is "-ve", add another bit into the * top half to negate the effect (i.e. 0xffff + 1 = 0x(1)0000). */ #define IMM_H(i) ((uintptr_t)(i)>>16) #define IMM_HA(i) (((uintptr_t)(i)>>16) + \ (((uintptr_t)(i) & 0x8000) >> 15)) #define IMM_L(i) ((uintptr_t)(i) & 0xffff) #define PLANT_INSTR(d, idx, instr) \ do { if (d) { (d)[idx] = instr; } idx++; } while (0) #define EMIT(instr) PLANT_INSTR(image, ctx->idx, instr) #define PPC_NOP() EMIT(PPC_INST_NOP) #define PPC_BLR() EMIT(PPC_INST_BLR) #define PPC_BLRL() EMIT(PPC_INST_BLRL) #define PPC_MTLR(r) EMIT(PPC_INST_MTLR | ___PPC_RT(r)) #define PPC_ADDI(d, a, i) EMIT(PPC_INST_ADDI | ___PPC_RT(d) | \ ___PPC_RA(a) | IMM_L(i)) #define PPC_MR(d, a) PPC_OR(d, a, a) #define PPC_LI(r, i) PPC_ADDI(r, 0, i) #define PPC_ADDIS(d, a, i) EMIT(PPC_INST_ADDIS | \ ___PPC_RS(d) | ___PPC_RA(a) | IMM_L(i)) #define PPC_LIS(r, i) PPC_ADDIS(r, 0, i) #define PPC_STD(r, base, i) EMIT(PPC_INST_STD | ___PPC_RS(r) | \ ___PPC_RA(base) | ((i) & 0xfffc)) #define PPC_LD(r, base, i) EMIT(PPC_INST_LD | ___PPC_RT(r) | \ ___PPC_RA(base) | IMM_L(i)) #define PPC_LWZ(r, base, i) EMIT(PPC_INST_LWZ | ___PPC_RT(r) | \ ___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)) /* 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)); \ PPC_LD(r, r, IMM_L(i)); } } while(0) #define PPC_LWZ_OFFS(r, base, i) do { if ((i) < 32768) PPC_LWZ(r, base, i); \ else { PPC_ADDIS(r, base, IMM_HA(i)); \ PPC_LWZ(r, r, IMM_L(i)); } } while(0) #define PPC_LHZ_OFFS(r, base, i) do { if ((i) < 32768) PPC_LHZ(r, base, i); \ else { PPC_ADDIS(r, base, IMM_HA(i)); \ PPC_LHZ(r, r, IMM_L(i)); } } while(0) #define PPC_CMPWI(a, i) EMIT(PPC_INST_CMPWI | ___PPC_RA(a) | IMM_L(i)) #define PPC_CMPDI(a, i) EMIT(PPC_INST_CMPDI | ___PPC_RA(a) | IMM_L(i)) #define PPC_CMPLWI(a, i) EMIT(PPC_INST_CMPLWI | ___PPC_RA(a) | IMM_L(i)) #define PPC_CMPLW(a, b) EMIT(PPC_INST_CMPLW | ___PPC_RA(a) | ___PPC_RB(b)) #define PPC_SUB(d, a, b) EMIT(PPC_INST_SUB | ___PPC_RT(d) | \ ___PPC_RB(a) | ___PPC_RA(b)) #define PPC_ADD(d, a, b) EMIT(PPC_INST_ADD | ___PPC_RT(d) | \ ___PPC_RA(a) | ___PPC_RB(b)) #define PPC_MUL(d, a, b) EMIT(PPC_INST_MULLW | ___PPC_RT(d) | \ ___PPC_RA(a) | ___PPC_RB(b)) #define PPC_MULHWU(d, a, b) EMIT(PPC_INST_MULHWU | ___PPC_RT(d) | \ ___PPC_RA(a) | ___PPC_RB(b)) #define PPC_MULI(d, a, i) EMIT(PPC_INST_MULLI | ___PPC_RT(d) | \ ___PPC_RA(a) | IMM_L(i)) #define PPC_DIVWU(d, a, b) EMIT(PPC_INST_DIVWU | ___PPC_RT(d) | \ ___PPC_RA(a) | ___PPC_RB(b)) #define PPC_AND(d, a, b) EMIT(PPC_INST_AND | ___PPC_RA(d) | \ ___PPC_RS(a) | ___PPC_RB(b)) #define PPC_ANDI(d, a, i) EMIT(PPC_INST_ANDI | ___PPC_RA(d) | \ ___PPC_RS(a) | IMM_L(i)) #define PPC_AND_DOT(d, a, b) EMIT(PPC_INST_ANDDOT | ___PPC_RA(d) | \ ___PPC_RS(a) | ___PPC_RB(b)) #define PPC_OR(d, a, b) EMIT(PPC_INST_OR | ___PPC_RA(d) | \ ___PPC_RS(a) | ___PPC_RB(b)) #define PPC_ORI(d, a, i) EMIT(PPC_INST_ORI | ___PPC_RA(d) | \ ___PPC_RS(a) | IMM_L(i)) #define PPC_ORIS(d, a, i) EMIT(PPC_INST_ORIS | ___PPC_RA(d) | \ ___PPC_RS(a) | IMM_L(i)) #define PPC_XOR(d, a, b) EMIT(PPC_INST_XOR | ___PPC_RA(d) | \ ___PPC_RS(a) | ___PPC_RB(b)) #define PPC_XORI(d, a, i) EMIT(PPC_INST_XORI | ___PPC_RA(d) | \ ___PPC_RS(a) | IMM_L(i)) #define PPC_XORIS(d, a, i) EMIT(PPC_INST_XORIS | ___PPC_RA(d) | \ ___PPC_RS(a) | IMM_L(i)) #define PPC_SLW(d, a, s) EMIT(PPC_INST_SLW | ___PPC_RA(d) | \ ___PPC_RS(a) | ___PPC_RB(s)) #define PPC_SRW(d, a, s) EMIT(PPC_INST_SRW | ___PPC_RA(d) | \ ___PPC_RS(a) | ___PPC_RB(s)) /* slwi = rlwinm Rx, Ry, n, 0, 31-n */ #define PPC_SLWI(d, a, i) EMIT(PPC_INST_RLWINM | ___PPC_RA(d) | \ ___PPC_RS(a) | __PPC_SH(i) | \ __PPC_MB(0) | __PPC_ME(31-(i))) /* srwi = rlwinm Rx, Ry, 32-n, n, 31 */ #define PPC_SRWI(d, a, i) EMIT(PPC_INST_RLWINM | ___PPC_RA(d) | \ ___PPC_RS(a) | __PPC_SH(32-(i)) | \ __PPC_MB(i) | __PPC_ME(31)) /* sldi = rldicr Rx, Ry, n, 63-n */ #define PPC_SLDI(d, a, i) EMIT(PPC_INST_RLDICR | ___PPC_RA(d) | \ ___PPC_RS(a) | __PPC_SH(i) | \ __PPC_MB(63-(i)) | (((i) & 0x20) >> 4)) #define PPC_NEG(d, a) EMIT(PPC_INST_NEG | ___PPC_RT(d) | ___PPC_RA(a)) /* Long jump; (unconditional 'branch') */ #define PPC_JMP(dest) EMIT(PPC_INST_BRANCH | \ (((dest) - (ctx->idx * 4)) & 0x03fffffc)) /* "cond" here covers BO:BI fields. */ #define PPC_BCC_SHORT(cond, dest) EMIT(PPC_INST_BRANCH_COND | \ (((cond) & 0x3ff) << 16) | \ (((dest) - (ctx->idx * 4)) & \ 0xfffc)) #define PPC_LI32(d, i) do { PPC_LI(d, IMM_L(i)); \ if ((u32)(uintptr_t)(i) >= 32768) { \ PPC_ADDIS(d, d, IMM_HA(i)); \ } } while(0) #define PPC_LI64(d, i) do { \ if (!((uintptr_t)(i) & 0xffffffff00000000ULL)) \ PPC_LI32(d, i); \ else { \ PPC_LIS(d, ((uintptr_t)(i) >> 48)); \ if ((uintptr_t)(i) & 0x0000ffff00000000ULL) \ PPC_ORI(d, d, \ ((uintptr_t)(i) >> 32) & 0xffff); \ PPC_SLDI(d, d, 32); \ if ((uintptr_t)(i) & 0x00000000ffff0000ULL) \ PPC_ORIS(d, d, \ ((uintptr_t)(i) >> 16) & 0xffff); \ if ((uintptr_t)(i) & 0x000000000000ffffULL) \ PPC_ORI(d, d, (uintptr_t)(i) & 0xffff); \ } } while (0); static inline bool is_nearbranch(int offset) { return (offset < 32768) && (offset >= -32768); } /* * The fly in the ointment of code size changing from pass to pass is * avoided by padding the short branch case with a NOP. If code size differs * with different branch reaches we will have the issue of code moving from * one pass to the next and will need a few passes to converge on a stable * state. */ #define PPC_BCC(cond, dest) do { \ if (is_nearbranch((dest) - (ctx->idx * 4))) { \ PPC_BCC_SHORT(cond, dest); \ PPC_NOP(); \ } else { \ /* Flip the 'T or F' bit to invert comparison */ \ PPC_BCC_SHORT(cond ^ COND_CMP_TRUE, (ctx->idx+2)*4); \ PPC_JMP(dest); \ } } while(0) /* To create a branch condition, select a bit of cr0... */ #define CR0_LT 0 #define CR0_GT 1 #define CR0_EQ 2 /* ...and modify BO[3] */ #define COND_CMP_TRUE 0x100 #define COND_CMP_FALSE 0x000 /* Together, they make all required comparisons: */ #define COND_GT (CR0_GT | COND_CMP_TRUE) #define COND_GE (CR0_LT | COND_CMP_FALSE) #define COND_EQ (CR0_EQ | COND_CMP_TRUE) #define COND_NE (CR0_EQ | COND_CMP_FALSE) #define COND_LT (CR0_LT | COND_CMP_TRUE) #define SEEN_DATAREF 0x10000 /* might call external helpers */ #define SEEN_XREG 0x20000 /* X reg is used */ #define SEEN_MEM 0x40000 /* SEEN_MEM+(1<