arch/powerpc/include/asm/probes.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 #ifndef _ASM_POWERPC_PROBES_H
   3 #define _ASM_POWERPC_PROBES_H
   4 #ifdef __KERNEL__
   5 /*
   6  * Definitions common to probes files
   7  *
   8  * Copyright IBM Corporation, 2012
   9  */
  10 #include <linux/types.h>
  11 #include <asm/disassemble.h>
  12 #include <asm/ppc-opcode.h>
  13
  14 #define BREAKPOINT_INSTRUCTION  PPC_RAW_TRAP()  /* trap */
  15
  16 /* Trap definitions per ISA */
  17 #define IS_TW(instr)            (((instr) & 0xfc0007fe) == 0x7c000008)
  18 #define IS_TD(instr)            (((instr) & 0xfc0007fe) == 0x7c000088)
  19 #define IS_TDI(instr)           (((instr) & 0xfc000000) == 0x08000000)
  20 #define IS_TWI(instr)           (((instr) & 0xfc000000) == 0x0c000000)
  21
  22 #ifdef CONFIG_PPC64
  23 #define is_trap(instr)          (IS_TW(instr) || IS_TD(instr) || \
  24                                 IS_TWI(instr) || IS_TDI(instr))
  25 #else
  26 #define is_trap(instr)          (IS_TW(instr) || IS_TWI(instr))
  27 #endif /* CONFIG_PPC64 */
  28
  29 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
  30 #define MSR_SINGLESTEP  (MSR_DE)
  31 #else
  32 #define MSR_SINGLESTEP  (MSR_SE)
  33 #endif
  34
  35 static inline bool can_single_step(u32 inst)
  36 {
  37         switch (get_op(inst)) {
  38         case OP_TRAP_64:        return false;
  39         case OP_TRAP:           return false;
  40         case OP_SC:             return false;
  41         case OP_19:
  42                 switch (get_xop(inst)) {
  43                 case OP_19_XOP_RFID:            return false;
  44                 case OP_19_XOP_RFMCI:           return false;
  45                 case OP_19_XOP_RFDI:            return false;
  46                 case OP_19_XOP_RFI:             return false;
  47                 case OP_19_XOP_RFCI:            return false;
  48                 case OP_19_XOP_RFSCV:           return false;
  49                 case OP_19_XOP_HRFID:           return false;
  50                 case OP_19_XOP_URFID:           return false;
  51                 case OP_19_XOP_STOP:            return false;
  52                 case OP_19_XOP_DOZE:            return false;
  53                 case OP_19_XOP_NAP:             return false;
  54                 case OP_19_XOP_SLEEP:           return false;
  55                 case OP_19_XOP_RVWINKLE:        return false;
  56                 }
  57                 break;
  58         case OP_31:
  59                 switch (get_xop(inst)) {
  60                 case OP_31_XOP_TRAP:            return false;
  61                 case OP_31_XOP_TRAP_64:         return false;
  62                 case OP_31_XOP_MTMSR:           return false;
  63                 case OP_31_XOP_MTMSRD:          return false;
  64                 }
  65                 break;
  66         }
  67         return true;
  68 }
  69
  70 /* Enable single stepping for the current task */
  71 static inline void enable_single_step(struct pt_regs *regs)
  72 {
  73         regs_set_return_msr(regs, regs->msr | MSR_SINGLESTEP);
  74 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
  75         /*
  76          * We turn off Critical Input Exception(CE) to ensure that the single
  77          * step will be for the instruction we have the probe on; if we don't,
  78          * it is possible we'd get the single step reported for CE.
  79          */
  80         regs_set_return_msr(regs, regs->msr & ~MSR_CE);
  81         mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) | DBCR0_IC | DBCR0_IDM);
  82 #ifdef CONFIG_PPC_47x
  83         isync();
  84 #endif
  85 #endif
  86 }
  87
  88
  89 #endif /* __KERNEL__ */
  90 #endif  /* _ASM_POWERPC_PROBES_H */