bpf_jit.h 11 KB

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