arch/powerpc/include/asm/probes.h

/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef _ASM_POWERPC_PROBES_H
#define _ASM_POWERPC_PROBES_H
#ifdef __KERNEL__
/*
 * Definitions common to probes files
 *
 * Copyright IBM Corporation, 2012
 */
#include <linux/types.h>
#include <asm/disassemble.h>
#include <asm/ppc-opcode.h>

#define BREAKPOINT_INSTRUCTION	PPC_RAW_TRAP()	/* trap */

/* Trap definitions per ISA */
#define IS_TW(instr)		(((instr) & 0xfc0007fe) == 0x7c000008)
#define IS_TD(instr)		(((instr) & 0xfc0007fe) == 0x7c000088)
#define IS_TDI(instr)		(((instr) & 0xfc000000) == 0x08000000)
#define IS_TWI(instr)		(((instr) & 0xfc000000) == 0x0c000000)

#ifdef CONFIG_PPC64
#define is_trap(instr)		(IS_TW(instr) || IS_TD(instr) || \
				IS_TWI(instr) || IS_TDI(instr))
#else
#define is_trap(instr)		(IS_TW(instr) || IS_TWI(instr))
#endif /* CONFIG_PPC64 */

#ifdef CONFIG_PPC_ADV_DEBUG_REGS
#define MSR_SINGLESTEP	(MSR_DE)
#else
#define MSR_SINGLESTEP	(MSR_SE)
#endif

static inline bool can_single_step(u32 inst)
{
	switch (get_op(inst)) {
	case OP_TRAP_64:	return false;
	case OP_TRAP:		return false;
	case OP_SC:		return false;
	case OP_19:
		switch (get_xop(inst)) {
		case OP_19_XOP_RFID:		return false;
		case OP_19_XOP_RFMCI:		return false;
		case OP_19_XOP_RFDI:		return false;
		case OP_19_XOP_RFI:		return false;
		case OP_19_XOP_RFCI:		return false;
		case OP_19_XOP_RFSCV:		return false;
		case OP_19_XOP_HRFID:		return false;
		case OP_19_XOP_URFID:		return false;
		case OP_19_XOP_STOP:		return false;
		case OP_19_XOP_DOZE:		return false;
		case OP_19_XOP_NAP:		return false;
		case OP_19_XOP_SLEEP:		return false;
		case OP_19_XOP_RVWINKLE:	return false;
		}
		break;
	case OP_31:
		switch (get_xop(inst)) {
		case OP_31_XOP_TRAP:		return false;
		case OP_31_XOP_TRAP_64:		return false;
		case OP_31_XOP_MTMSR:		return false;
		case OP_31_XOP_MTMSRD:		return false;
		}
		break;
	}
	return true;
}

/* Enable single stepping for the current task */
static inline void enable_single_step(struct pt_regs *regs)
{
	regs_set_return_msr(regs, regs->msr | MSR_SINGLESTEP);
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
	/*
	 * We turn off Critical Input Exception(CE) to ensure that the single
	 * step will be for the instruction we have the probe on; if we don't,
	 * it is possible we'd get the single step reported for CE.
	 */
	regs_set_return_msr(regs, regs->msr & ~MSR_CE);
	mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) | DBCR0_IC | DBCR0_IDM);
#ifdef CONFIG_PPC_47x
	isync();
#endif
#endif
}


#endif /* __KERNEL__ */
#endif	/* _ASM_POWERPC_PROBES_H */