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  
can_single_step(u32 inst)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 */
enable_single_step(struct pt_regs * regs)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 */
91