xref: /openbmc/linux/arch/powerpc/include/asm/probes.h (revision ca637c0e)
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 */
91