driver.c 3.0 KB

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  1. // SPDX-License-Identifier: GPL-2.0-or-later
  2. /*
  3. * Linux/PA-RISC Project (http://www.parisc-linux.org/)
  4. *
  5. * Floating-point emulation code
  6. * Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org>
  7. */
  8. /*
  9. * linux/arch/math-emu/driver.c.c
  10. *
  11. * decodes and dispatches unimplemented FPU instructions
  12. *
  13. * Copyright (C) 1999, 2000 Philipp Rumpf <prumpf@tux.org>
  14. * Copyright (C) 2001 Hewlett-Packard <bame@debian.org>
  15. */
  16. #include <linux/sched/signal.h>
  17. #include "float.h"
  18. #include "math-emu.h"
  19. #define fptpos 31
  20. #define fpr1pos 10
  21. #define extru(r,pos,len) (((r) >> (31-(pos))) & (( 1 << (len)) - 1))
  22. #define FPUDEBUG 0
  23. /* Format of the floating-point exception registers. */
  24. struct exc_reg {
  25. unsigned int exception : 6;
  26. unsigned int ei : 26;
  27. };
  28. /* Macros for grabbing bits of the instruction format from the 'ei'
  29. field above. */
  30. /* Major opcode 0c and 0e */
  31. #define FP0CE_UID(i) (((i) >> 6) & 3)
  32. #define FP0CE_CLASS(i) (((i) >> 9) & 3)
  33. #define FP0CE_SUBOP(i) (((i) >> 13) & 7)
  34. #define FP0CE_SUBOP1(i) (((i) >> 15) & 7) /* Class 1 subopcode */
  35. #define FP0C_FORMAT(i) (((i) >> 11) & 3)
  36. #define FP0E_FORMAT(i) (((i) >> 11) & 1)
  37. /* Major opcode 0c, uid 2 (performance monitoring) */
  38. #define FPPM_SUBOP(i) (((i) >> 9) & 0x1f)
  39. /* Major opcode 2e (fused operations). */
  40. #define FP2E_SUBOP(i) (((i) >> 5) & 1)
  41. #define FP2E_FORMAT(i) (((i) >> 11) & 1)
  42. /* Major opcode 26 (FMPYSUB) */
  43. /* Major opcode 06 (FMPYADD) */
  44. #define FPx6_FORMAT(i) ((i) & 0x1f)
  45. /* Flags and enable bits of the status word. */
  46. #define FPSW_FLAGS(w) ((w) >> 27)
  47. #define FPSW_ENABLE(w) ((w) & 0x1f)
  48. #define FPSW_V (1<<4)
  49. #define FPSW_Z (1<<3)
  50. #define FPSW_O (1<<2)
  51. #define FPSW_U (1<<1)
  52. #define FPSW_I (1<<0)
  53. /* Handle a floating point exception. Return zero if the faulting
  54. instruction can be completed successfully. */
  55. int
  56. handle_fpe(struct pt_regs *regs)
  57. {
  58. extern void printbinary(unsigned long x, int nbits);
  59. unsigned int orig_sw, sw;
  60. int signalcode;
  61. /* need an intermediate copy of float regs because FPU emulation
  62. * code expects an artificial last entry which contains zero
  63. *
  64. * also, the passed in fr registers contain one word that defines
  65. * the fpu type. the fpu type information is constructed
  66. * inside the emulation code
  67. */
  68. __u64 frcopy[36];
  69. memcpy(frcopy, regs->fr, sizeof regs->fr);
  70. frcopy[32] = 0;
  71. memcpy(&orig_sw, frcopy, sizeof(orig_sw));
  72. if (FPUDEBUG) {
  73. printk(KERN_DEBUG "FP VZOUICxxxxCQCQCQCQCQCRMxxTDVZOUI ->\n ");
  74. printbinary(orig_sw, 32);
  75. printk(KERN_DEBUG "\n");
  76. }
  77. signalcode = decode_fpu(frcopy, 0x666);
  78. /* Status word = FR0L. */
  79. memcpy(&sw, frcopy, sizeof(sw));
  80. if (FPUDEBUG) {
  81. printk(KERN_DEBUG "VZOUICxxxxCQCQCQCQCQCRMxxTDVZOUI decode_fpu returns %d|0x%x\n",
  82. signalcode >> 24, signalcode & 0xffffff);
  83. printbinary(sw, 32);
  84. printk(KERN_DEBUG "\n");
  85. }
  86. memcpy(regs->fr, frcopy, sizeof regs->fr);
  87. if (signalcode != 0) {
  88. force_sig_fault(signalcode >> 24, signalcode & 0xffffff,
  89. (void __user *) regs->iaoq[0]);
  90. return -1;
  91. }
  92. return signalcode ? -1 : 0;
  93. }