arch/powerpc/net/bpf_jit.h

   1 /*
   2  * bpf_jit.h: BPF JIT compiler for PPC
   3  *
   4  * Copyright 2011 Matt Evans <matt@ozlabs.org>, IBM Corporation
   5  *           2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; version 2
  10  * of the License.
  11  */
  12 #ifndef _BPF_JIT_H
  13 #define _BPF_JIT_H
  14
  15 #ifndef __ASSEMBLY__
  16
  17 #include <asm/types.h>
  18
  19 #ifdef PPC64_ELF_ABI_v1
  20 #define FUNCTION_DESCR_SIZE     24
  21 #else
  22 #define FUNCTION_DESCR_SIZE     0
  23 #endif
  24
  25 /*
  26  * 16-bit immediate helper macros: HA() is for use with sign-extending instrs
  27  * (e.g. LD, ADDI).  If the bottom 16 bits is "-ve", add another bit into the
  28  * top half to negate the effect (i.e. 0xffff + 1 = 0x(1)0000).
  29  */
  30 #define IMM_H(i)                ((uintptr_t)(i)>>16)
  31 #define IMM_HA(i)               (((uintptr_t)(i)>>16) +                       \
  32                                         (((uintptr_t)(i) & 0x8000) >> 15))
  33 #define IMM_L(i)                ((uintptr_t)(i) & 0xffff)
  34
  35 #define PLANT_INSTR(d, idx, instr)                                            \
  36         do { if (d) { (d)[idx] = instr; } idx++; } while (0)
  37 #define EMIT(instr)             PLANT_INSTR(image, ctx->idx, instr)
  38
  39 #define PPC_NOP()               EMIT(PPC_INST_NOP)
  40 #define PPC_BLR()               EMIT(PPC_INST_BLR)
  41 #define PPC_BLRL()              EMIT(PPC_INST_BLRL)
  42 #define PPC_MTLR(r)             EMIT(PPC_INST_MTLR | ___PPC_RT(r))
  43 #define PPC_ADDI(d, a, i)       EMIT(PPC_INST_ADDI | ___PPC_RT(d) |           \
  44                                      ___PPC_RA(a) | IMM_L(i))
  45 #define PPC_MR(d, a)            PPC_OR(d, a, a)
  46 #define PPC_LI(r, i)            PPC_ADDI(r, 0, i)
  47 #define PPC_ADDIS(d, a, i)      EMIT(PPC_INST_ADDIS |                         \
  48                                      ___PPC_RT(d) | ___PPC_RA(a) | IMM_L(i))
  49 #define PPC_LIS(r, i)           PPC_ADDIS(r, 0, i)
  50 #define PPC_STD(r, base, i)     EMIT(PPC_INST_STD | ___PPC_RS(r) |            \
  51                                      ___PPC_RA(base) | ((i) & 0xfffc))
  52 #define PPC_STDU(r, base, i)    EMIT(PPC_INST_STDU | ___PPC_RS(r) |           \
  53                                      ___PPC_RA(base) | ((i) & 0xfffc))
  54 #define PPC_STW(r, base, i)     EMIT(PPC_INST_STW | ___PPC_RS(r) |            \
  55                                      ___PPC_RA(base) | IMM_L(i))
  56 #define PPC_STWU(r, base, i)    EMIT(PPC_INST_STWU | ___PPC_RS(r) |           \
  57                                      ___PPC_RA(base) | IMM_L(i))
  58 #define PPC_STH(r, base, i)     EMIT(PPC_INST_STH | ___PPC_RS(r) |            \
  59                                      ___PPC_RA(base) | IMM_L(i))
  60 #define PPC_STB(r, base, i)     EMIT(PPC_INST_STB | ___PPC_RS(r) |            \
  61                                      ___PPC_RA(base) | IMM_L(i))
  62
  63 #define PPC_LBZ(r, base, i)     EMIT(PPC_INST_LBZ | ___PPC_RT(r) |            \
  64                                      ___PPC_RA(base) | IMM_L(i))
  65 #define PPC_LD(r, base, i)      EMIT(PPC_INST_LD | ___PPC_RT(r) |             \
  66                                      ___PPC_RA(base) | IMM_L(i))
  67 #define PPC_LWZ(r, base, i)     EMIT(PPC_INST_LWZ | ___PPC_RT(r) |            \
  68                                      ___PPC_RA(base) | IMM_L(i))
  69 #define PPC_LHZ(r, base, i)     EMIT(PPC_INST_LHZ | ___PPC_RT(r) |            \
  70                                      ___PPC_RA(base) | IMM_L(i))
  71 #define PPC_LHBRX(r, base, b)   EMIT(PPC_INST_LHBRX | ___PPC_RT(r) |          \
  72                                      ___PPC_RA(base) | ___PPC_RB(b))
  73 #define PPC_LDBRX(r, base, b)   EMIT(PPC_INST_LDBRX | ___PPC_RT(r) |          \
  74                                      ___PPC_RA(base) | ___PPC_RB(b))
  75
  76 #define PPC_BPF_LDARX(t, a, b, eh) EMIT(PPC_INST_LDARX | ___PPC_RT(t) |       \
  77                                         ___PPC_RA(a) | ___PPC_RB(b) |         \
  78                                         __PPC_EH(eh))
  79 #define PPC_BPF_LWARX(t, a, b, eh) EMIT(PPC_INST_LWARX | ___PPC_RT(t) |       \
  80                                         ___PPC_RA(a) | ___PPC_RB(b) |         \
  81                                         __PPC_EH(eh))
  82 #define PPC_BPF_STWCX(s, a, b)  EMIT(PPC_INST_STWCX | ___PPC_RS(s) |          \
  83                                         ___PPC_RA(a) | ___PPC_RB(b))
  84 #define PPC_BPF_STDCX(s, a, b)  EMIT(PPC_INST_STDCX | ___PPC_RS(s) |          \
  85                                         ___PPC_RA(a) | ___PPC_RB(b))
  86
  87 #ifdef CONFIG_PPC64
  88 #define PPC_BPF_LL(r, base, i) do { PPC_LD(r, base, i); } while(0)
  89 #define PPC_BPF_STL(r, base, i) do { PPC_STD(r, base, i); } while(0)
  90 #define PPC_BPF_STLU(r, base, i) do { PPC_STDU(r, base, i); } while(0)
  91 #else
  92 #define PPC_BPF_LL(r, base, i) do { PPC_LWZ(r, base, i); } while(0)
  93 #define PPC_BPF_STL(r, base, i) do { PPC_STW(r, base, i); } while(0)
  94 #define PPC_BPF_STLU(r, base, i) do { PPC_STWU(r, base, i); } while(0)
  95 #endif
  96
  97 #define PPC_CMPWI(a, i)         EMIT(PPC_INST_CMPWI | ___PPC_RA(a) | IMM_L(i))
  98 #define PPC_CMPDI(a, i)         EMIT(PPC_INST_CMPDI | ___PPC_RA(a) | IMM_L(i))
  99 #define PPC_CMPW(a, b)          EMIT(PPC_INST_CMPW | ___PPC_RA(a) |           \
 100                                         ___PPC_RB(b))
 101 #define PPC_CMPD(a, b)          EMIT(PPC_INST_CMPD | ___PPC_RA(a) |           \
 102                                         ___PPC_RB(b))
 103 #define PPC_CMPLWI(a, i)        EMIT(PPC_INST_CMPLWI | ___PPC_RA(a) | IMM_L(i))
 104 #define PPC_CMPLDI(a, i)        EMIT(PPC_INST_CMPLDI | ___PPC_RA(a) | IMM_L(i))
 105 #define PPC_CMPLW(a, b)         EMIT(PPC_INST_CMPLW | ___PPC_RA(a) |          \
 106                                         ___PPC_RB(b))
 107 #define PPC_CMPLD(a, b)         EMIT(PPC_INST_CMPLD | ___PPC_RA(a) |          \
 108                                         ___PPC_RB(b))
 109
 110 #define PPC_SUB(d, a, b)        EMIT(PPC_INST_SUB | ___PPC_RT(d) |            \
 111                                      ___PPC_RB(a) | ___PPC_RA(b))
 112 #define PPC_ADD(d, a, b)        EMIT(PPC_INST_ADD | ___PPC_RT(d) |            \
 113                                      ___PPC_RA(a) | ___PPC_RB(b))
 114 #define PPC_MULD(d, a, b)       EMIT(PPC_INST_MULLD | ___PPC_RT(d) |          \
 115                                      ___PPC_RA(a) | ___PPC_RB(b))
 116 #define PPC_MULW(d, a, b)       EMIT(PPC_INST_MULLW | ___PPC_RT(d) |          \
 117                                      ___PPC_RA(a) | ___PPC_RB(b))
 118 #define PPC_MULHWU(d, a, b)     EMIT(PPC_INST_MULHWU | ___PPC_RT(d) |         \
 119                                      ___PPC_RA(a) | ___PPC_RB(b))
 120 #define PPC_MULI(d, a, i)       EMIT(PPC_INST_MULLI | ___PPC_RT(d) |          \
 121                                      ___PPC_RA(a) | IMM_L(i))
 122 #define PPC_DIVWU(d, a, b)      EMIT(PPC_INST_DIVWU | ___PPC_RT(d) |          \
 123                                      ___PPC_RA(a) | ___PPC_RB(b))
 124 #define PPC_DIVD(d, a, b)       EMIT(PPC_INST_DIVD | ___PPC_RT(d) |           \
 125                                      ___PPC_RA(a) | ___PPC_RB(b))
 126 #define PPC_AND(d, a, b)        EMIT(PPC_INST_AND | ___PPC_RA(d) |            \
 127                                      ___PPC_RS(a) | ___PPC_RB(b))
 128 #define PPC_ANDI(d, a, i)       EMIT(PPC_INST_ANDI | ___PPC_RA(d) |           \
 129                                      ___PPC_RS(a) | IMM_L(i))
 130 #define PPC_AND_DOT(d, a, b)    EMIT(PPC_INST_ANDDOT | ___PPC_RA(d) |         \
 131                                      ___PPC_RS(a) | ___PPC_RB(b))
 132 #define PPC_OR(d, a, b)         EMIT(PPC_INST_OR | ___PPC_RA(d) |             \
 133                                      ___PPC_RS(a) | ___PPC_RB(b))
 134 #define PPC_MR(d, a)            PPC_OR(d, a, a)
 135 #define PPC_ORI(d, a, i)        EMIT(PPC_INST_ORI | ___PPC_RA(d) |            \
 136                                      ___PPC_RS(a) | IMM_L(i))
 137 #define PPC_ORIS(d, a, i)       EMIT(PPC_INST_ORIS | ___PPC_RA(d) |           \
 138                                      ___PPC_RS(a) | IMM_L(i))
 139 #define PPC_XOR(d, a, b)        EMIT(PPC_INST_XOR | ___PPC_RA(d) |            \
 140                                      ___PPC_RS(a) | ___PPC_RB(b))
 141 #define PPC_XORI(d, a, i)       EMIT(PPC_INST_XORI | ___PPC_RA(d) |           \
 142                                      ___PPC_RS(a) | IMM_L(i))
 143 #define PPC_XORIS(d, a, i)      EMIT(PPC_INST_XORIS | ___PPC_RA(d) |          \
 144                                      ___PPC_RS(a) | IMM_L(i))
 145 #define PPC_EXTSW(d, a)         EMIT(PPC_INST_EXTSW | ___PPC_RA(d) |          \
 146                                      ___PPC_RS(a))
 147 #define PPC_SLW(d, a, s)        EMIT(PPC_INST_SLW | ___PPC_RA(d) |            \
 148                                      ___PPC_RS(a) | ___PPC_RB(s))
 149 #define PPC_SLD(d, a, s)        EMIT(PPC_INST_SLD | ___PPC_RA(d) |            \
 150                                      ___PPC_RS(a) | ___PPC_RB(s))
 151 #define PPC_SRW(d, a, s)        EMIT(PPC_INST_SRW | ___PPC_RA(d) |            \
 152                                      ___PPC_RS(a) | ___PPC_RB(s))
 153 #define PPC_SRD(d, a, s)        EMIT(PPC_INST_SRD | ___PPC_RA(d) |            \
 154                                      ___PPC_RS(a) | ___PPC_RB(s))
 155 #define PPC_SRAD(d, a, s)       EMIT(PPC_INST_SRAD | ___PPC_RA(d) |           \
 156                                      ___PPC_RS(a) | ___PPC_RB(s))
 157 #define PPC_SRADI(d, a, i)      EMIT(PPC_INST_SRADI | ___PPC_RA(d) |          \
 158                                      ___PPC_RS(a) | __PPC_SH(i) |             \
 159                                      (((i) & 0x20) >> 4))
 160 #define PPC_RLWINM(d, a, i, mb, me)     EMIT(PPC_INST_RLWINM | ___PPC_RA(d) | \
 161                                         ___PPC_RS(a) | __PPC_SH(i) |          \
 162                                         __PPC_MB(mb) | __PPC_ME(me))
 163 #define PPC_RLWIMI(d, a, i, mb, me)     EMIT(PPC_INST_RLWIMI | ___PPC_RA(d) | \
 164                                         ___PPC_RS(a) | __PPC_SH(i) |          \
 165                                         __PPC_MB(mb) | __PPC_ME(me))
 166 #define PPC_RLDICL(d, a, i, mb)         EMIT(PPC_INST_RLDICL | ___PPC_RA(d) | \
 167                                         ___PPC_RS(a) | __PPC_SH(i) |          \
 168                                         __PPC_MB64(mb) | (((i) & 0x20) >> 4))
 169 #define PPC_RLDICR(d, a, i, me)         EMIT(PPC_INST_RLDICR | ___PPC_RA(d) | \
 170                                         ___PPC_RS(a) | __PPC_SH(i) |          \
 171                                         __PPC_ME64(me) | (((i) & 0x20) >> 4))
 172
 173 /* slwi = rlwinm Rx, Ry, n, 0, 31-n */
 174 #define PPC_SLWI(d, a, i)       PPC_RLWINM(d, a, i, 0, 31-(i))
 175 /* srwi = rlwinm Rx, Ry, 32-n, n, 31 */
 176 #define PPC_SRWI(d, a, i)       PPC_RLWINM(d, a, 32-(i), i, 31)
 177 /* sldi = rldicr Rx, Ry, n, 63-n */
 178 #define PPC_SLDI(d, a, i)       PPC_RLDICR(d, a, i, 63-(i))
 179 /* sldi = rldicl Rx, Ry, 64-n, n */
 180 #define PPC_SRDI(d, a, i)       PPC_RLDICL(d, a, 64-(i), i)
 181
 182 #define PPC_NEG(d, a)           EMIT(PPC_INST_NEG | ___PPC_RT(d) | ___PPC_RA(a))
 183
 184 /* Long jump; (unconditional 'branch') */
 185 #define PPC_JMP(dest)           EMIT(PPC_INST_BRANCH |                        \
 186                                      (((dest) - (ctx->idx * 4)) & 0x03fffffc))
 187 /* "cond" here covers BO:BI fields. */
 188 #define PPC_BCC_SHORT(cond, dest)       EMIT(PPC_INST_BRANCH_COND |           \
 189                                              (((cond) & 0x3ff) << 16) |       \
 190                                              (((dest) - (ctx->idx * 4)) &     \
 191                                               0xfffc))
 192 /* Sign-extended 32-bit immediate load */
 193 #define PPC_LI32(d, i)          do {                                          \
 194                 if ((int)(uintptr_t)(i) >= -32768 &&                          \
 195                                 (int)(uintptr_t)(i) < 32768)                  \
 196                         PPC_LI(d, i);                                         \
 197                 else {                                                        \
 198                         PPC_LIS(d, IMM_H(i));                                 \
 199                         if (IMM_L(i))                                         \
 200                                 PPC_ORI(d, d, IMM_L(i));                      \
 201                 } } while(0)
 202
 203 #define PPC_LI64(d, i)          do {                                          \
 204                 if ((long)(i) >= -2147483648 &&                               \
 205                                 (long)(i) < 2147483648)                       \
 206                         PPC_LI32(d, i);                                       \
 207                 else {                                                        \
 208                         if (!((uintptr_t)(i) & 0xffff800000000000ULL))        \
 209                                 PPC_LI(d, ((uintptr_t)(i) >> 32) & 0xffff);   \
 210                         else {                                                \
 211                                 PPC_LIS(d, ((uintptr_t)(i) >> 48));           \
 212                                 if ((uintptr_t)(i) & 0x0000ffff00000000ULL)   \
 213                                         PPC_ORI(d, d,                         \
 214                                           ((uintptr_t)(i) >> 32) & 0xffff);   \
 215                         }                                                     \
 216                         PPC_SLDI(d, d, 32);                                   \
 217                         if ((uintptr_t)(i) & 0x00000000ffff0000ULL)           \
 218                                 PPC_ORIS(d, d,                                \
 219                                          ((uintptr_t)(i) >> 16) & 0xffff);    \
 220                         if ((uintptr_t)(i) & 0x000000000000ffffULL)           \
 221                                 PPC_ORI(d, d, (uintptr_t)(i) & 0xffff);       \
 222                 } } while (0)
 223
 224 #ifdef CONFIG_PPC64
 225 #define PPC_FUNC_ADDR(d,i) do { PPC_LI64(d, i); } while(0)
 226 #else
 227 #define PPC_FUNC_ADDR(d,i) do { PPC_LI32(d, i); } while(0)
 228 #endif
 229
 230 static inline bool is_nearbranch(int offset)
 231 {
 232         return (offset < 32768) && (offset >= -32768);
 233 }
 234
 235 /*
 236  * The fly in the ointment of code size changing from pass to pass is
 237  * avoided by padding the short branch case with a NOP.  If code size differs
 238  * with different branch reaches we will have the issue of code moving from
 239  * one pass to the next and will need a few passes to converge on a stable
 240  * state.
 241  */
 242 #define PPC_BCC(cond, dest)     do {                                          \
 243                 if (is_nearbranch((dest) - (ctx->idx * 4))) {                 \
 244                         PPC_BCC_SHORT(cond, dest);                            \
 245                         PPC_NOP();                                            \
 246                 } else {                                                      \
 247                         /* Flip the 'T or F' bit to invert comparison */      \
 248                         PPC_BCC_SHORT(cond ^ COND_CMP_TRUE, (ctx->idx+2)*4);  \
 249                         PPC_JMP(dest);                                        \
 250                 } } while(0)
 251
 252 /* To create a branch condition, select a bit of cr0... */
 253 #define CR0_LT          0
 254 #define CR0_GT          1
 255 #define CR0_EQ          2
 256 /* ...and modify BO[3] */
 257 #define COND_CMP_TRUE   0x100
 258 #define COND_CMP_FALSE  0x000
 259 /* Together, they make all required comparisons: */
 260 #define COND_GT         (CR0_GT | COND_CMP_TRUE)
 261 #define COND_GE         (CR0_LT | COND_CMP_FALSE)
 262 #define COND_EQ         (CR0_EQ | COND_CMP_TRUE)
 263 #define COND_NE         (CR0_EQ | COND_CMP_FALSE)
 264 #define COND_LT         (CR0_LT | COND_CMP_TRUE)
 265
 266 #endif
 267
 268 #endif