xref: /openbmc/linux/arch/powerpc/include/asm/probes.h (revision 2cf1c348)
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 
12 typedef u32 ppc_opcode_t;
13 #define BREAKPOINT_INSTRUCTION	0x7fe00008	/* trap */
14 
15 /* Trap definitions per ISA */
16 #define IS_TW(instr)		(((instr) & 0xfc0007fe) == 0x7c000008)
17 #define IS_TD(instr)		(((instr) & 0xfc0007fe) == 0x7c000088)
18 #define IS_TDI(instr)		(((instr) & 0xfc000000) == 0x08000000)
19 #define IS_TWI(instr)		(((instr) & 0xfc000000) == 0x0c000000)
20 
21 #ifdef CONFIG_PPC64
22 #define is_trap(instr)		(IS_TW(instr) || IS_TD(instr) || \
23 				IS_TWI(instr) || IS_TDI(instr))
24 #else
25 #define is_trap(instr)		(IS_TW(instr) || IS_TWI(instr))
26 #endif /* CONFIG_PPC64 */
27 
28 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
29 #define MSR_SINGLESTEP	(MSR_DE)
30 #else
31 #define MSR_SINGLESTEP	(MSR_SE)
32 #endif
33 
34 /* Enable single stepping for the current task */
35 static inline void enable_single_step(struct pt_regs *regs)
36 {
37 	regs_set_return_msr(regs, regs->msr | MSR_SINGLESTEP);
38 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
39 	/*
40 	 * We turn off Critical Input Exception(CE) to ensure that the single
41 	 * step will be for the instruction we have the probe on; if we don't,
42 	 * it is possible we'd get the single step reported for CE.
43 	 */
44 	regs_set_return_msr(regs, regs->msr & ~MSR_CE);
45 	mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) | DBCR0_IC | DBCR0_IDM);
46 #ifdef CONFIG_PPC_47x
47 	isync();
48 #endif
49 #endif
50 }
51 
52 
53 #endif /* __KERNEL__ */
54 #endif	/* _ASM_POWERPC_PROBES_H */
55