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From:   Michael Ellerman <mpe@ellerman.id.au>
To:     Christophe Leroy <christophe.leroy@c-s.fr>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>, mikey@neuling.org
Cc:     linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v5 10/13] powerpc/ptrace: split out ADV_DEBUG_REGS related functions.
In-Reply-To: <e2bd7d275bd5933d848aad4fee3ca652a14d039b.1582848567.git.christophe.leroy@c-s.fr>
References: <cover.1582848567.git.christophe.leroy@c-s.fr> <e2bd7d275bd5933d848aad4fee3ca652a14d039b.1582848567.git.christophe.leroy@c-s.fr>
Date:   Fri, 20 Mar 2020 13:12:20 +1100
Message-ID: <87imizdbaz.fsf@mpe.ellerman.id.au>
MIME-Version: 1.0
Content-Type: text/plain
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Christophe Leroy <christophe.leroy@c-s.fr> writes:
> Move ADV_DEBUG_REGS functions out of ptrace.c, into
> ptrace-adv.c and ptrace-noadv.c
>
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
> ---
> v4: Leave hw_breakpoint.h for ptrace.c
> ---
>  arch/powerpc/kernel/ptrace/Makefile       |   4 +
>  arch/powerpc/kernel/ptrace/ptrace-adv.c   | 468 ++++++++++++++++
>  arch/powerpc/kernel/ptrace/ptrace-decl.h  |   5 +
>  arch/powerpc/kernel/ptrace/ptrace-noadv.c | 236 ++++++++
>  arch/powerpc/kernel/ptrace/ptrace.c       | 650 ----------------------
>  5 files changed, 713 insertions(+), 650 deletions(-)
>  create mode 100644 arch/powerpc/kernel/ptrace/ptrace-adv.c
>  create mode 100644 arch/powerpc/kernel/ptrace/ptrace-noadv.c

This is somehow breaking the ptrace-hwbreak selftest on Power8:

  test: ptrace-hwbreak
  tags: git_version:v5.6-rc6-892-g7a285a6067d6
  PTRACE_SET_DEBUGREG, WO, len: 1: Ok
  PTRACE_SET_DEBUGREG, WO, len: 2: Ok
  PTRACE_SET_DEBUGREG, WO, len: 4: Ok
  PTRACE_SET_DEBUGREG, WO, len: 8: Ok
  PTRACE_SET_DEBUGREG, RO, len: 1: Ok
  PTRACE_SET_DEBUGREG, RO, len: 2: Ok
  PTRACE_SET_DEBUGREG, RO, len: 4: Ok
  PTRACE_SET_DEBUGREG, RO, len: 8: Ok
  PTRACE_SET_DEBUGREG, RW, len: 1: Ok
  PTRACE_SET_DEBUGREG, RW, len: 2: Ok
  PTRACE_SET_DEBUGREG, RW, len: 4: Ok
  PTRACE_SET_DEBUGREG, RW, len: 8: Ok
  PPC_PTRACE_SETHWDEBUG, MODE_EXACT, WO, len: 1: Ok
  PPC_PTRACE_SETHWDEBUG, MODE_EXACT, RO, len: 1: Ok
  PPC_PTRACE_SETHWDEBUG, MODE_EXACT, RW, len: 1: Ok
  PPC_PTRACE_SETHWDEBUG, MODE_RANGE, DW ALIGNED, WO, len: 6: Ok
  PPC_PTRACE_SETHWDEBUG, MODE_RANGE, DW ALIGNED, RO, len: 6: Ok
  PPC_PTRACE_SETHWDEBUG, MODE_RANGE, DW ALIGNED, RW, len: 6: Ok
  PPC_PTRACE_SETHWDEBUG, MODE_RANGE, DW UNALIGNED, WO, len: 6: Ok
  PPC_PTRACE_SETHWDEBUG, MODE_RANGE, DW UNALIGNED, RO, len: 6: Fail
  failure: ptrace-hwbreak

I haven't had time to work out why yet.

cheers

> diff --git a/arch/powerpc/kernel/ptrace/Makefile b/arch/powerpc/kernel/ptrace/Makefile
> index 7addc5994bb9..e9d97c2d063e 100644
> --- a/arch/powerpc/kernel/ptrace/Makefile
> +++ b/arch/powerpc/kernel/ptrace/Makefile
> @@ -14,3 +14,7 @@ endif
>  obj-$(CONFIG_ALTIVEC)		+= ptrace-altivec.o
>  obj-$(CONFIG_SPE)		+= ptrace-spe.o
>  obj-$(CONFIG_PPC_TRANSACTIONAL_MEM)	+= ptrace-tm.o
> +obj-$(CONFIG_PPC_ADV_DEBUG_REGS)	+= ptrace-adv.o
> +ifneq ($(CONFIG_PPC_ADV_DEBUG_REGS),y)
> +obj-y				+= ptrace-noadv.o
> +endif
> diff --git a/arch/powerpc/kernel/ptrace/ptrace-adv.c b/arch/powerpc/kernel/ptrace/ptrace-adv.c
> new file mode 100644
> index 000000000000..eebcd41edc3d
> --- /dev/null
> +++ b/arch/powerpc/kernel/ptrace/ptrace-adv.c
> @@ -0,0 +1,468 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +
> +#include <linux/regset.h>
> +#include <linux/hw_breakpoint.h>
> +
> +#include "ptrace-decl.h"
> +
> +void user_enable_single_step(struct task_struct *task)
> +{
> +	struct pt_regs *regs = task->thread.regs;
> +
> +	if (regs != NULL) {
> +		task->thread.debug.dbcr0 &= ~DBCR0_BT;
> +		task->thread.debug.dbcr0 |= DBCR0_IDM | DBCR0_IC;
> +		regs->msr |= MSR_DE;
> +	}
> +	set_tsk_thread_flag(task, TIF_SINGLESTEP);
> +}
> +
> +void user_enable_block_step(struct task_struct *task)
> +{
> +	struct pt_regs *regs = task->thread.regs;
> +
> +	if (regs != NULL) {
> +		task->thread.debug.dbcr0 &= ~DBCR0_IC;
> +		task->thread.debug.dbcr0 = DBCR0_IDM | DBCR0_BT;
> +		regs->msr |= MSR_DE;
> +	}
> +	set_tsk_thread_flag(task, TIF_SINGLESTEP);
> +}
> +
> +void user_disable_single_step(struct task_struct *task)
> +{
> +	struct pt_regs *regs = task->thread.regs;
> +
> +	if (regs != NULL) {
> +		/*
> +		 * The logic to disable single stepping should be as
> +		 * simple as turning off the Instruction Complete flag.
> +		 * And, after doing so, if all debug flags are off, turn
> +		 * off DBCR0(IDM) and MSR(DE) .... Torez
> +		 */
> +		task->thread.debug.dbcr0 &= ~(DBCR0_IC | DBCR0_BT);
> +		/*
> +		 * Test to see if any of the DBCR_ACTIVE_EVENTS bits are set.
> +		 */
> +		if (!DBCR_ACTIVE_EVENTS(task->thread.debug.dbcr0,
> +					task->thread.debug.dbcr1)) {
> +			/*
> +			 * All debug events were off.....
> +			 */
> +			task->thread.debug.dbcr0 &= ~DBCR0_IDM;
> +			regs->msr &= ~MSR_DE;
> +		}
> +	}
> +	clear_tsk_thread_flag(task, TIF_SINGLESTEP);
> +}
> +
> +int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, unsigned long data)
> +{
> +#ifdef CONFIG_HAVE_HW_BREAKPOINT
> +	int ret;
> +	struct thread_struct *thread = &task->thread;
> +	struct perf_event *bp;
> +	struct perf_event_attr attr;
> +#endif /* CONFIG_HAVE_HW_BREAKPOINT */
> +
> +	/* For ppc64 we support one DABR and no IABR's at the moment (ppc64).
> +	 *  For embedded processors we support one DAC and no IAC's at the
> +	 *  moment.
> +	 */
> +	if (addr > 0)
> +		return -EINVAL;
> +
> +	/* The bottom 3 bits in dabr are flags */
> +	if ((data & ~0x7UL) >= TASK_SIZE)
> +		return -EIO;
> +
> +	/* As described above, it was assumed 3 bits were passed with the data
> +	 *  address, but we will assume only the mode bits will be passed
> +	 *  as to not cause alignment restrictions for DAC-based processors.
> +	 */
> +
> +	/* DAC's hold the whole address without any mode flags */
> +	task->thread.debug.dac1 = data & ~0x3UL;
> +
> +	if (task->thread.debug.dac1 == 0) {
> +		dbcr_dac(task) &= ~(DBCR_DAC1R | DBCR_DAC1W);
> +		if (!DBCR_ACTIVE_EVENTS(task->thread.debug.dbcr0,
> +					task->thread.debug.dbcr1)) {
> +			task->thread.regs->msr &= ~MSR_DE;
> +			task->thread.debug.dbcr0 &= ~DBCR0_IDM;
> +		}
> +		return 0;
> +	}
> +
> +	/* Read or Write bits must be set */
> +
> +	if (!(data & 0x3UL))
> +		return -EINVAL;
> +
> +	/* Set the Internal Debugging flag (IDM bit 1) for the DBCR0 register */
> +	task->thread.debug.dbcr0 |= DBCR0_IDM;
> +
> +	/* Check for write and read flags and set DBCR0 accordingly */
> +	dbcr_dac(task) &= ~(DBCR_DAC1R | DBCR_DAC1W);
> +	if (data & 0x1UL)
> +		dbcr_dac(task) |= DBCR_DAC1R;
> +	if (data & 0x2UL)
> +		dbcr_dac(task) |= DBCR_DAC1W;
> +	task->thread.regs->msr |= MSR_DE;
> +	return 0;
> +}
> +
> +static long set_instruction_bp(struct task_struct *child,
> +			       struct ppc_hw_breakpoint *bp_info)
> +{
> +	int slot;
> +	int slot1_in_use = ((child->thread.debug.dbcr0 & DBCR0_IAC1) != 0);
> +	int slot2_in_use = ((child->thread.debug.dbcr0 & DBCR0_IAC2) != 0);
> +	int slot3_in_use = ((child->thread.debug.dbcr0 & DBCR0_IAC3) != 0);
> +	int slot4_in_use = ((child->thread.debug.dbcr0 & DBCR0_IAC4) != 0);
> +
> +	if (dbcr_iac_range(child) & DBCR_IAC12MODE)
> +		slot2_in_use = 1;
> +	if (dbcr_iac_range(child) & DBCR_IAC34MODE)
> +		slot4_in_use = 1;
> +
> +	if (bp_info->addr >= TASK_SIZE)
> +		return -EIO;
> +
> +	if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT) {
> +		/* Make sure range is valid. */
> +		if (bp_info->addr2 >= TASK_SIZE)
> +			return -EIO;
> +
> +		/* We need a pair of IAC regsisters */
> +		if (!slot1_in_use && !slot2_in_use) {
> +			slot = 1;
> +			child->thread.debug.iac1 = bp_info->addr;
> +			child->thread.debug.iac2 = bp_info->addr2;
> +			child->thread.debug.dbcr0 |= DBCR0_IAC1;
> +			if (bp_info->addr_mode ==
> +					PPC_BREAKPOINT_MODE_RANGE_EXCLUSIVE)
> +				dbcr_iac_range(child) |= DBCR_IAC12X;
> +			else
> +				dbcr_iac_range(child) |= DBCR_IAC12I;
> +#if CONFIG_PPC_ADV_DEBUG_IACS > 2
> +		} else if ((!slot3_in_use) && (!slot4_in_use)) {
> +			slot = 3;
> +			child->thread.debug.iac3 = bp_info->addr;
> +			child->thread.debug.iac4 = bp_info->addr2;
> +			child->thread.debug.dbcr0 |= DBCR0_IAC3;
> +			if (bp_info->addr_mode ==
> +					PPC_BREAKPOINT_MODE_RANGE_EXCLUSIVE)
> +				dbcr_iac_range(child) |= DBCR_IAC34X;
> +			else
> +				dbcr_iac_range(child) |= DBCR_IAC34I;
> +#endif
> +		} else {
> +			return -ENOSPC;
> +		}
> +	} else {
> +		/* We only need one.  If possible leave a pair free in
> +		 * case a range is needed later
> +		 */
> +		if (!slot1_in_use) {
> +			/*
> +			 * Don't use iac1 if iac1-iac2 are free and either
> +			 * iac3 or iac4 (but not both) are free
> +			 */
> +			if (slot2_in_use || slot3_in_use == slot4_in_use) {
> +				slot = 1;
> +				child->thread.debug.iac1 = bp_info->addr;
> +				child->thread.debug.dbcr0 |= DBCR0_IAC1;
> +				goto out;
> +			}
> +		}
> +		if (!slot2_in_use) {
> +			slot = 2;
> +			child->thread.debug.iac2 = bp_info->addr;
> +			child->thread.debug.dbcr0 |= DBCR0_IAC2;
> +#if CONFIG_PPC_ADV_DEBUG_IACS > 2
> +		} else if (!slot3_in_use) {
> +			slot = 3;
> +			child->thread.debug.iac3 = bp_info->addr;
> +			child->thread.debug.dbcr0 |= DBCR0_IAC3;
> +		} else if (!slot4_in_use) {
> +			slot = 4;
> +			child->thread.debug.iac4 = bp_info->addr;
> +			child->thread.debug.dbcr0 |= DBCR0_IAC4;
> +#endif
> +		} else {
> +			return -ENOSPC;
> +		}
> +	}
> +out:
> +	child->thread.debug.dbcr0 |= DBCR0_IDM;
> +	child->thread.regs->msr |= MSR_DE;
> +
> +	return slot;
> +}
> +
> +static int del_instruction_bp(struct task_struct *child, int slot)
> +{
> +	switch (slot) {
> +	case 1:
> +		if ((child->thread.debug.dbcr0 & DBCR0_IAC1) == 0)
> +			return -ENOENT;
> +
> +		if (dbcr_iac_range(child) & DBCR_IAC12MODE) {
> +			/* address range - clear slots 1 & 2 */
> +			child->thread.debug.iac2 = 0;
> +			dbcr_iac_range(child) &= ~DBCR_IAC12MODE;
> +		}
> +		child->thread.debug.iac1 = 0;
> +		child->thread.debug.dbcr0 &= ~DBCR0_IAC1;
> +		break;
> +	case 2:
> +		if ((child->thread.debug.dbcr0 & DBCR0_IAC2) == 0)
> +			return -ENOENT;
> +
> +		if (dbcr_iac_range(child) & DBCR_IAC12MODE)
> +			/* used in a range */
> +			return -EINVAL;
> +		child->thread.debug.iac2 = 0;
> +		child->thread.debug.dbcr0 &= ~DBCR0_IAC2;
> +		break;
> +#if CONFIG_PPC_ADV_DEBUG_IACS > 2
> +	case 3:
> +		if ((child->thread.debug.dbcr0 & DBCR0_IAC3) == 0)
> +			return -ENOENT;
> +
> +		if (dbcr_iac_range(child) & DBCR_IAC34MODE) {
> +			/* address range - clear slots 3 & 4 */
> +			child->thread.debug.iac4 = 0;
> +			dbcr_iac_range(child) &= ~DBCR_IAC34MODE;
> +		}
> +		child->thread.debug.iac3 = 0;
> +		child->thread.debug.dbcr0 &= ~DBCR0_IAC3;
> +		break;
> +	case 4:
> +		if ((child->thread.debug.dbcr0 & DBCR0_IAC4) == 0)
> +			return -ENOENT;
> +
> +		if (dbcr_iac_range(child) & DBCR_IAC34MODE)
> +			/* Used in a range */
> +			return -EINVAL;
> +		child->thread.debug.iac4 = 0;
> +		child->thread.debug.dbcr0 &= ~DBCR0_IAC4;
> +		break;
> +#endif
> +	default:
> +		return -EINVAL;
> +	}
> +	return 0;
> +}
> +
> +static int set_dac(struct task_struct *child, struct ppc_hw_breakpoint *bp_info)
> +{
> +	int byte_enable =
> +		(bp_info->condition_mode >> PPC_BREAKPOINT_CONDITION_BE_SHIFT)
> +		& 0xf;
> +	int condition_mode =
> +		bp_info->condition_mode & PPC_BREAKPOINT_CONDITION_MODE;
> +	int slot;
> +
> +	if (byte_enable && condition_mode == 0)
> +		return -EINVAL;
> +
> +	if (bp_info->addr >= TASK_SIZE)
> +		return -EIO;
> +
> +	if ((dbcr_dac(child) & (DBCR_DAC1R | DBCR_DAC1W)) == 0) {
> +		slot = 1;
> +		if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
> +			dbcr_dac(child) |= DBCR_DAC1R;
> +		if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
> +			dbcr_dac(child) |= DBCR_DAC1W;
> +		child->thread.debug.dac1 = (unsigned long)bp_info->addr;
> +#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
> +		if (byte_enable) {
> +			child->thread.debug.dvc1 =
> +				(unsigned long)bp_info->condition_value;
> +			child->thread.debug.dbcr2 |=
> +				((byte_enable << DBCR2_DVC1BE_SHIFT) |
> +				 (condition_mode << DBCR2_DVC1M_SHIFT));
> +		}
> +#endif
> +#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
> +	} else if (child->thread.debug.dbcr2 & DBCR2_DAC12MODE) {
> +		/* Both dac1 and dac2 are part of a range */
> +		return -ENOSPC;
> +#endif
> +	} else if ((dbcr_dac(child) & (DBCR_DAC2R | DBCR_DAC2W)) == 0) {
> +		slot = 2;
> +		if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
> +			dbcr_dac(child) |= DBCR_DAC2R;
> +		if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
> +			dbcr_dac(child) |= DBCR_DAC2W;
> +		child->thread.debug.dac2 = (unsigned long)bp_info->addr;
> +#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
> +		if (byte_enable) {
> +			child->thread.debug.dvc2 =
> +				(unsigned long)bp_info->condition_value;
> +			child->thread.debug.dbcr2 |=
> +				((byte_enable << DBCR2_DVC2BE_SHIFT) |
> +				 (condition_mode << DBCR2_DVC2M_SHIFT));
> +		}
> +#endif
> +	} else {
> +		return -ENOSPC;
> +	}
> +	child->thread.debug.dbcr0 |= DBCR0_IDM;
> +	child->thread.regs->msr |= MSR_DE;
> +
> +	return slot + 4;
> +}
> +
> +static int del_dac(struct task_struct *child, int slot)
> +{
> +	if (slot == 1) {
> +		if ((dbcr_dac(child) & (DBCR_DAC1R | DBCR_DAC1W)) == 0)
> +			return -ENOENT;
> +
> +		child->thread.debug.dac1 = 0;
> +		dbcr_dac(child) &= ~(DBCR_DAC1R | DBCR_DAC1W);
> +#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
> +		if (child->thread.debug.dbcr2 & DBCR2_DAC12MODE) {
> +			child->thread.debug.dac2 = 0;
> +			child->thread.debug.dbcr2 &= ~DBCR2_DAC12MODE;
> +		}
> +		child->thread.debug.dbcr2 &= ~(DBCR2_DVC1M | DBCR2_DVC1BE);
> +#endif
> +#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
> +		child->thread.debug.dvc1 = 0;
> +#endif
> +	} else if (slot == 2) {
> +		if ((dbcr_dac(child) & (DBCR_DAC2R | DBCR_DAC2W)) == 0)
> +			return -ENOENT;
> +
> +#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
> +		if (child->thread.debug.dbcr2 & DBCR2_DAC12MODE)
> +			/* Part of a range */
> +			return -EINVAL;
> +		child->thread.debug.dbcr2 &= ~(DBCR2_DVC2M | DBCR2_DVC2BE);
> +#endif
> +#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
> +		child->thread.debug.dvc2 = 0;
> +#endif
> +		child->thread.debug.dac2 = 0;
> +		dbcr_dac(child) &= ~(DBCR_DAC2R | DBCR_DAC2W);
> +	} else {
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
> +static int set_dac_range(struct task_struct *child,
> +			 struct ppc_hw_breakpoint *bp_info)
> +{
> +	int mode = bp_info->addr_mode & PPC_BREAKPOINT_MODE_MASK;
> +
> +	/* We don't allow range watchpoints to be used with DVC */
> +	if (bp_info->condition_mode)
> +		return -EINVAL;
> +
> +	/*
> +	 * Best effort to verify the address range.  The user/supervisor bits
> +	 * prevent trapping in kernel space, but let's fail on an obvious bad
> +	 * range.  The simple test on the mask is not fool-proof, and any
> +	 * exclusive range will spill over into kernel space.
> +	 */
> +	if (bp_info->addr >= TASK_SIZE)
> +		return -EIO;
> +	if (mode == PPC_BREAKPOINT_MODE_MASK) {
> +		/*
> +		 * dac2 is a bitmask.  Don't allow a mask that makes a
> +		 * kernel space address from a valid dac1 value
> +		 */
> +		if (~((unsigned long)bp_info->addr2) >= TASK_SIZE)
> +			return -EIO;
> +	} else {
> +		/*
> +		 * For range breakpoints, addr2 must also be a valid address
> +		 */
> +		if (bp_info->addr2 >= TASK_SIZE)
> +			return -EIO;
> +	}
> +
> +	if (child->thread.debug.dbcr0 &
> +	    (DBCR0_DAC1R | DBCR0_DAC1W | DBCR0_DAC2R | DBCR0_DAC2W))
> +		return -ENOSPC;
> +
> +	if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
> +		child->thread.debug.dbcr0 |= (DBCR0_DAC1R | DBCR0_IDM);
> +	if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
> +		child->thread.debug.dbcr0 |= (DBCR0_DAC1W | DBCR0_IDM);
> +	child->thread.debug.dac1 = bp_info->addr;
> +	child->thread.debug.dac2 = bp_info->addr2;
> +	if (mode == PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE)
> +		child->thread.debug.dbcr2  |= DBCR2_DAC12M;
> +	else if (mode == PPC_BREAKPOINT_MODE_RANGE_EXCLUSIVE)
> +		child->thread.debug.dbcr2  |= DBCR2_DAC12MX;
> +	else	/* PPC_BREAKPOINT_MODE_MASK */
> +		child->thread.debug.dbcr2  |= DBCR2_DAC12MM;
> +	child->thread.regs->msr |= MSR_DE;
> +
> +	return 5;
> +}
> +#endif /* CONFIG_PPC_ADV_DEBUG_DAC_RANGE */
> +
> +long ppc_set_hwdebug(struct task_struct *child, struct ppc_hw_breakpoint *bp_info)
> +{
> +	if (bp_info->version != 1)
> +		return -ENOTSUPP;
> +	/*
> +	 * Check for invalid flags and combinations
> +	 */
> +	if (bp_info->trigger_type == 0 ||
> +	    (bp_info->trigger_type & ~(PPC_BREAKPOINT_TRIGGER_EXECUTE |
> +				       PPC_BREAKPOINT_TRIGGER_RW)) ||
> +	    (bp_info->addr_mode & ~PPC_BREAKPOINT_MODE_MASK) ||
> +	    (bp_info->condition_mode &
> +	     ~(PPC_BREAKPOINT_CONDITION_MODE |
> +	       PPC_BREAKPOINT_CONDITION_BE_ALL)))
> +		return -EINVAL;
> +#if CONFIG_PPC_ADV_DEBUG_DVCS == 0
> +	if (bp_info->condition_mode != PPC_BREAKPOINT_CONDITION_NONE)
> +		return -EINVAL;
> +#endif
> +
> +	if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_EXECUTE) {
> +		if (bp_info->trigger_type != PPC_BREAKPOINT_TRIGGER_EXECUTE ||
> +		    bp_info->condition_mode != PPC_BREAKPOINT_CONDITION_NONE)
> +			return -EINVAL;
> +		return set_instruction_bp(child, bp_info);
> +	}
> +	if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_EXACT)
> +		return set_dac(child, bp_info);
> +
> +#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
> +	return set_dac_range(child, bp_info);
> +#else
> +	return -EINVAL;
> +#endif
> +}
> +
> +long ppc_del_hwdebug(struct task_struct *child, long data)
> +{
> +	int rc;
> +
> +	if (data <= 4)
> +		rc = del_instruction_bp(child, (int)data);
> +	else
> +		rc = del_dac(child, (int)data - 4);
> +
> +	if (!rc) {
> +		if (!DBCR_ACTIVE_EVENTS(child->thread.debug.dbcr0,
> +					child->thread.debug.dbcr1)) {
> +			child->thread.debug.dbcr0 &= ~DBCR0_IDM;
> +			child->thread.regs->msr &= ~MSR_DE;
> +		}
> +	}
> +	return rc;
> +}
> diff --git a/arch/powerpc/kernel/ptrace/ptrace-decl.h b/arch/powerpc/kernel/ptrace/ptrace-decl.h
> index e12f6615fc1d..bdba09a87aea 100644
> --- a/arch/powerpc/kernel/ptrace/ptrace-decl.h
> +++ b/arch/powerpc/kernel/ptrace/ptrace-decl.h
> @@ -174,3 +174,8 @@ int tm_cgpr32_set(struct task_struct *target, const struct user_regset *regset,
>  /* ptrace-view */
>  
>  extern const struct user_regset_view user_ppc_native_view;
> +
> +/* ptrace-(no)adv */
> +int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, unsigned long data);
> +long ppc_set_hwdebug(struct task_struct *child, struct ppc_hw_breakpoint *bp_info);
> +long ppc_del_hwdebug(struct task_struct *child, long data);
> diff --git a/arch/powerpc/kernel/ptrace/ptrace-noadv.c b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
> new file mode 100644
> index 000000000000..cf05fadba0d5
> --- /dev/null
> +++ b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
> @@ -0,0 +1,236 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +
> +#include <linux/regset.h>
> +#include <linux/hw_breakpoint.h>
> +
> +#include <asm/debug.h>
> +
> +#include "ptrace-decl.h"
> +
> +void user_enable_single_step(struct task_struct *task)
> +{
> +	struct pt_regs *regs = task->thread.regs;
> +
> +	if (regs != NULL) {
> +		regs->msr &= ~MSR_BE;
> +		regs->msr |= MSR_SE;
> +	}
> +	set_tsk_thread_flag(task, TIF_SINGLESTEP);
> +}
> +
> +void user_enable_block_step(struct task_struct *task)
> +{
> +	struct pt_regs *regs = task->thread.regs;
> +
> +	if (regs != NULL) {
> +		regs->msr &= ~MSR_SE;
> +		regs->msr |= MSR_BE;
> +	}
> +	set_tsk_thread_flag(task, TIF_SINGLESTEP);
> +}
> +
> +void user_disable_single_step(struct task_struct *task)
> +{
> +	struct pt_regs *regs = task->thread.regs;
> +
> +	if (regs != NULL)
> +		regs->msr &= ~(MSR_SE | MSR_BE);
> +
> +	clear_tsk_thread_flag(task, TIF_SINGLESTEP);
> +}
> +
> +int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, unsigned long data)
> +{
> +#ifdef CONFIG_HAVE_HW_BREAKPOINT
> +	int ret;
> +	struct thread_struct *thread = &task->thread;
> +	struct perf_event *bp;
> +	struct perf_event_attr attr;
> +#endif /* CONFIG_HAVE_HW_BREAKPOINT */
> +	bool set_bp = true;
> +	struct arch_hw_breakpoint hw_brk;
> +
> +	/* For ppc64 we support one DABR and no IABR's at the moment (ppc64).
> +	 *  For embedded processors we support one DAC and no IAC's at the
> +	 *  moment.
> +	 */
> +	if (addr > 0)
> +		return -EINVAL;
> +
> +	/* The bottom 3 bits in dabr are flags */
> +	if ((data & ~0x7UL) >= TASK_SIZE)
> +		return -EIO;
> +
> +	/* For processors using DABR (i.e. 970), the bottom 3 bits are flags.
> +	 *  It was assumed, on previous implementations, that 3 bits were
> +	 *  passed together with the data address, fitting the design of the
> +	 *  DABR register, as follows:
> +	 *
> +	 *  bit 0: Read flag
> +	 *  bit 1: Write flag
> +	 *  bit 2: Breakpoint translation
> +	 *
> +	 *  Thus, we use them here as so.
> +	 */
> +
> +	/* Ensure breakpoint translation bit is set */
> +	if (data && !(data & HW_BRK_TYPE_TRANSLATE))
> +		return -EIO;
> +	hw_brk.address = data & (~HW_BRK_TYPE_DABR);
> +	hw_brk.type = (data & HW_BRK_TYPE_DABR) | HW_BRK_TYPE_PRIV_ALL;
> +	hw_brk.len = DABR_MAX_LEN;
> +	hw_brk.hw_len = DABR_MAX_LEN;
> +	set_bp = (data) && (hw_brk.type & HW_BRK_TYPE_RDWR);
> +#ifdef CONFIG_HAVE_HW_BREAKPOINT
> +	bp = thread->ptrace_bps[0];
> +	if (!set_bp) {
> +		if (bp) {
> +			unregister_hw_breakpoint(bp);
> +			thread->ptrace_bps[0] = NULL;
> +		}
> +		return 0;
> +	}
> +	if (bp) {
> +		attr = bp->attr;
> +		attr.bp_addr = hw_brk.address;
> +		attr.bp_len = DABR_MAX_LEN;
> +		arch_bp_generic_fields(hw_brk.type, &attr.bp_type);
> +
> +		/* Enable breakpoint */
> +		attr.disabled = false;
> +
> +		ret =  modify_user_hw_breakpoint(bp, &attr);
> +		if (ret)
> +			return ret;
> +
> +		thread->ptrace_bps[0] = bp;
> +		thread->hw_brk = hw_brk;
> +		return 0;
> +	}
> +
> +	/* Create a new breakpoint request if one doesn't exist already */
> +	hw_breakpoint_init(&attr);
> +	attr.bp_addr = hw_brk.address;
> +	attr.bp_len = DABR_MAX_LEN;
> +	arch_bp_generic_fields(hw_brk.type,
> +			       &attr.bp_type);
> +
> +	thread->ptrace_bps[0] = bp = register_user_hw_breakpoint(&attr,
> +					       ptrace_triggered, NULL, task);
> +	if (IS_ERR(bp)) {
> +		thread->ptrace_bps[0] = NULL;
> +		return PTR_ERR(bp);
> +	}
> +
> +#else /* !CONFIG_HAVE_HW_BREAKPOINT */
> +	if (set_bp && (!ppc_breakpoint_available()))
> +		return -ENODEV;
> +#endif /* CONFIG_HAVE_HW_BREAKPOINT */
> +	task->thread.hw_brk = hw_brk;
> +	return 0;
> +}
> +
> +long ppc_set_hwdebug(struct task_struct *child, struct ppc_hw_breakpoint *bp_info)
> +{
> +#ifdef CONFIG_HAVE_HW_BREAKPOINT
> +	int len = 0;
> +	struct thread_struct *thread = &child->thread;
> +	struct perf_event *bp;
> +	struct perf_event_attr attr;
> +#endif /* CONFIG_HAVE_HW_BREAKPOINT */
> +	struct arch_hw_breakpoint brk;
> +
> +	if (bp_info->version != 1)
> +		return -ENOTSUPP;
> +	/*
> +	 * We only support one data breakpoint
> +	 */
> +	if ((bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_RW) == 0 ||
> +	    (bp_info->trigger_type & ~PPC_BREAKPOINT_TRIGGER_RW) != 0 ||
> +	    bp_info->condition_mode != PPC_BREAKPOINT_CONDITION_NONE)
> +		return -EINVAL;
> +
> +	if ((unsigned long)bp_info->addr >= TASK_SIZE)
> +		return -EIO;
> +
> +	brk.address = bp_info->addr & ~7UL;
> +	brk.type = HW_BRK_TYPE_TRANSLATE;
> +	brk.len = DABR_MAX_LEN;
> +	if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
> +		brk.type |= HW_BRK_TYPE_READ;
> +	if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
> +		brk.type |= HW_BRK_TYPE_WRITE;
> +#ifdef CONFIG_HAVE_HW_BREAKPOINT
> +	/*
> +	 * Check if the request is for 'range' breakpoints. We can
> +	 * support it if range < 8 bytes.
> +	 */
> +	if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE)
> +		len = bp_info->addr2 - bp_info->addr;
> +	else if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_EXACT)
> +		len = 1;
> +	else
> +		return -EINVAL;
> +	bp = thread->ptrace_bps[0];
> +	if (bp)
> +		return -ENOSPC;
> +
> +	/* Create a new breakpoint request if one doesn't exist already */
> +	hw_breakpoint_init(&attr);
> +	attr.bp_addr = (unsigned long)bp_info->addr & ~HW_BREAKPOINT_ALIGN;
> +	attr.bp_len = len;
> +	arch_bp_generic_fields(brk.type, &attr.bp_type);
> +
> +	bp = register_user_hw_breakpoint(&attr, ptrace_triggered, NULL, child);
> +	thread->ptrace_bps[0] = bp;
> +	if (IS_ERR(bp)) {
> +		thread->ptrace_bps[0] = NULL;
> +		return PTR_ERR(bp);
> +	}
> +
> +	return 1;
> +#endif /* CONFIG_HAVE_HW_BREAKPOINT */
> +
> +	if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT)
> +		return -EINVAL;
> +
> +	if (child->thread.hw_brk.address)
> +		return -ENOSPC;
> +
> +	if (!ppc_breakpoint_available())
> +		return -ENODEV;
> +
> +	child->thread.hw_brk = brk;
> +
> +	return 1;
> +}
> +
> +long ppc_del_hwdebug(struct task_struct *child, long data)
> +{
> +#ifdef CONFIG_HAVE_HW_BREAKPOINT
> +	int ret = 0;
> +	struct thread_struct *thread = &child->thread;
> +	struct perf_event *bp;
> +#endif /* CONFIG_HAVE_HW_BREAKPOINT */
> +	if (data != 1)
> +		return -EINVAL;
> +
> +#ifdef CONFIG_HAVE_HW_BREAKPOINT
> +	bp = thread->ptrace_bps[0];
> +	if (bp) {
> +		unregister_hw_breakpoint(bp);
> +		thread->ptrace_bps[0] = NULL;
> +	} else {
> +		ret = -ENOENT;
> +	}
> +	return ret;
> +#else /* CONFIG_HAVE_HW_BREAKPOINT */
> +	if (child->thread.hw_brk.address == 0)
> +		return -ENOENT;
> +
> +	child->thread.hw_brk.address = 0;
> +	child->thread.hw_brk.type = 0;
> +#endif /* CONFIG_HAVE_HW_BREAKPOINT */
> +
> +	return 0;
> +}
> diff --git a/arch/powerpc/kernel/ptrace/ptrace.c b/arch/powerpc/kernel/ptrace/ptrace.c
> index 95e66dad32e0..48e095e88a2f 100644
> --- a/arch/powerpc/kernel/ptrace/ptrace.c
> +++ b/arch/powerpc/kernel/ptrace/ptrace.c
> @@ -31,71 +31,6 @@
>  
>  #include "ptrace-decl.h"
>  
> -void user_enable_single_step(struct task_struct *task)
> -{
> -	struct pt_regs *regs = task->thread.regs;
> -
> -	if (regs != NULL) {
> -#ifdef CONFIG_PPC_ADV_DEBUG_REGS
> -		task->thread.debug.dbcr0 &= ~DBCR0_BT;
> -		task->thread.debug.dbcr0 |= DBCR0_IDM | DBCR0_IC;
> -		regs->msr |= MSR_DE;
> -#else
> -		regs->msr &= ~MSR_BE;
> -		regs->msr |= MSR_SE;
> -#endif
> -	}
> -	set_tsk_thread_flag(task, TIF_SINGLESTEP);
> -}
> -
> -void user_enable_block_step(struct task_struct *task)
> -{
> -	struct pt_regs *regs = task->thread.regs;
> -
> -	if (regs != NULL) {
> -#ifdef CONFIG_PPC_ADV_DEBUG_REGS
> -		task->thread.debug.dbcr0 &= ~DBCR0_IC;
> -		task->thread.debug.dbcr0 = DBCR0_IDM | DBCR0_BT;
> -		regs->msr |= MSR_DE;
> -#else
> -		regs->msr &= ~MSR_SE;
> -		regs->msr |= MSR_BE;
> -#endif
> -	}
> -	set_tsk_thread_flag(task, TIF_SINGLESTEP);
> -}
> -
> -void user_disable_single_step(struct task_struct *task)
> -{
> -	struct pt_regs *regs = task->thread.regs;
> -
> -	if (regs != NULL) {
> -#ifdef CONFIG_PPC_ADV_DEBUG_REGS
> -		/*
> -		 * The logic to disable single stepping should be as
> -		 * simple as turning off the Instruction Complete flag.
> -		 * And, after doing so, if all debug flags are off, turn
> -		 * off DBCR0(IDM) and MSR(DE) .... Torez
> -		 */
> -		task->thread.debug.dbcr0 &= ~(DBCR0_IC|DBCR0_BT);
> -		/*
> -		 * Test to see if any of the DBCR_ACTIVE_EVENTS bits are set.
> -		 */
> -		if (!DBCR_ACTIVE_EVENTS(task->thread.debug.dbcr0,
> -					task->thread.debug.dbcr1)) {
> -			/*
> -			 * All debug events were off.....
> -			 */
> -			task->thread.debug.dbcr0 &= ~DBCR0_IDM;
> -			regs->msr &= ~MSR_DE;
> -		}
> -#else
> -		regs->msr &= ~(MSR_SE | MSR_BE);
> -#endif
> -	}
> -	clear_tsk_thread_flag(task, TIF_SINGLESTEP);
> -}
> -
>  #ifdef CONFIG_HAVE_HW_BREAKPOINT
>  void ptrace_triggered(struct perf_event *bp,
>  		      struct perf_sample_data *data, struct pt_regs *regs)
> @@ -114,138 +49,6 @@ void ptrace_triggered(struct perf_event *bp,
>  }
>  #endif /* CONFIG_HAVE_HW_BREAKPOINT */
>  
> -static int ptrace_set_debugreg(struct task_struct *task, unsigned long addr,
> -			       unsigned long data)
> -{
> -#ifdef CONFIG_HAVE_HW_BREAKPOINT
> -	int ret;
> -	struct thread_struct *thread = &(task->thread);
> -	struct perf_event *bp;
> -	struct perf_event_attr attr;
> -#endif /* CONFIG_HAVE_HW_BREAKPOINT */
> -#ifndef CONFIG_PPC_ADV_DEBUG_REGS
> -	bool set_bp = true;
> -	struct arch_hw_breakpoint hw_brk;
> -#endif
> -
> -	/* For ppc64 we support one DABR and no IABR's at the moment (ppc64).
> -	 *  For embedded processors we support one DAC and no IAC's at the
> -	 *  moment.
> -	 */
> -	if (addr > 0)
> -		return -EINVAL;
> -
> -	/* The bottom 3 bits in dabr are flags */
> -	if ((data & ~0x7UL) >= TASK_SIZE)
> -		return -EIO;
> -
> -#ifndef CONFIG_PPC_ADV_DEBUG_REGS
> -	/* For processors using DABR (i.e. 970), the bottom 3 bits are flags.
> -	 *  It was assumed, on previous implementations, that 3 bits were
> -	 *  passed together with the data address, fitting the design of the
> -	 *  DABR register, as follows:
> -	 *
> -	 *  bit 0: Read flag
> -	 *  bit 1: Write flag
> -	 *  bit 2: Breakpoint translation
> -	 *
> -	 *  Thus, we use them here as so.
> -	 */
> -
> -	/* Ensure breakpoint translation bit is set */
> -	if (data && !(data & HW_BRK_TYPE_TRANSLATE))
> -		return -EIO;
> -	hw_brk.address = data & (~HW_BRK_TYPE_DABR);
> -	hw_brk.type = (data & HW_BRK_TYPE_DABR) | HW_BRK_TYPE_PRIV_ALL;
> -	hw_brk.len = DABR_MAX_LEN;
> -	hw_brk.hw_len = DABR_MAX_LEN;
> -	set_bp = (data) && (hw_brk.type & HW_BRK_TYPE_RDWR);
> -#ifdef CONFIG_HAVE_HW_BREAKPOINT
> -	bp = thread->ptrace_bps[0];
> -	if (!set_bp) {
> -		if (bp) {
> -			unregister_hw_breakpoint(bp);
> -			thread->ptrace_bps[0] = NULL;
> -		}
> -		return 0;
> -	}
> -	if (bp) {
> -		attr = bp->attr;
> -		attr.bp_addr = hw_brk.address;
> -		attr.bp_len = DABR_MAX_LEN;
> -		arch_bp_generic_fields(hw_brk.type, &attr.bp_type);
> -
> -		/* Enable breakpoint */
> -		attr.disabled = false;
> -
> -		ret =  modify_user_hw_breakpoint(bp, &attr);
> -		if (ret) {
> -			return ret;
> -		}
> -		thread->ptrace_bps[0] = bp;
> -		thread->hw_brk = hw_brk;
> -		return 0;
> -	}
> -
> -	/* Create a new breakpoint request if one doesn't exist already */
> -	hw_breakpoint_init(&attr);
> -	attr.bp_addr = hw_brk.address;
> -	attr.bp_len = DABR_MAX_LEN;
> -	arch_bp_generic_fields(hw_brk.type,
> -			       &attr.bp_type);
> -
> -	thread->ptrace_bps[0] = bp = register_user_hw_breakpoint(&attr,
> -					       ptrace_triggered, NULL, task);
> -	if (IS_ERR(bp)) {
> -		thread->ptrace_bps[0] = NULL;
> -		return PTR_ERR(bp);
> -	}
> -
> -#else /* !CONFIG_HAVE_HW_BREAKPOINT */
> -	if (set_bp && (!ppc_breakpoint_available()))
> -		return -ENODEV;
> -#endif /* CONFIG_HAVE_HW_BREAKPOINT */
> -	task->thread.hw_brk = hw_brk;
> -#else /* CONFIG_PPC_ADV_DEBUG_REGS */
> -	/* As described above, it was assumed 3 bits were passed with the data
> -	 *  address, but we will assume only the mode bits will be passed
> -	 *  as to not cause alignment restrictions for DAC-based processors.
> -	 */
> -
> -	/* DAC's hold the whole address without any mode flags */
> -	task->thread.debug.dac1 = data & ~0x3UL;
> -
> -	if (task->thread.debug.dac1 == 0) {
> -		dbcr_dac(task) &= ~(DBCR_DAC1R | DBCR_DAC1W);
> -		if (!DBCR_ACTIVE_EVENTS(task->thread.debug.dbcr0,
> -					task->thread.debug.dbcr1)) {
> -			task->thread.regs->msr &= ~MSR_DE;
> -			task->thread.debug.dbcr0 &= ~DBCR0_IDM;
> -		}
> -		return 0;
> -	}
> -
> -	/* Read or Write bits must be set */
> -
> -	if (!(data & 0x3UL))
> -		return -EINVAL;
> -
> -	/* Set the Internal Debugging flag (IDM bit 1) for the DBCR0
> -	   register */
> -	task->thread.debug.dbcr0 |= DBCR0_IDM;
> -
> -	/* Check for write and read flags and set DBCR0
> -	   accordingly */
> -	dbcr_dac(task) &= ~(DBCR_DAC1R|DBCR_DAC1W);
> -	if (data & 0x1UL)
> -		dbcr_dac(task) |= DBCR_DAC1R;
> -	if (data & 0x2UL)
> -		dbcr_dac(task) |= DBCR_DAC1W;
> -	task->thread.regs->msr |= MSR_DE;
> -#endif /* CONFIG_PPC_ADV_DEBUG_REGS */
> -	return 0;
> -}
> -
>  /*
>   * Called by kernel/ptrace.c when detaching..
>   *
> @@ -257,459 +60,6 @@ void ptrace_disable(struct task_struct *child)
>  	user_disable_single_step(child);
>  }
>  
> -#ifdef CONFIG_PPC_ADV_DEBUG_REGS
> -static long set_instruction_bp(struct task_struct *child,
> -			      struct ppc_hw_breakpoint *bp_info)
> -{
> -	int slot;
> -	int slot1_in_use = ((child->thread.debug.dbcr0 & DBCR0_IAC1) != 0);
> -	int slot2_in_use = ((child->thread.debug.dbcr0 & DBCR0_IAC2) != 0);
> -	int slot3_in_use = ((child->thread.debug.dbcr0 & DBCR0_IAC3) != 0);
> -	int slot4_in_use = ((child->thread.debug.dbcr0 & DBCR0_IAC4) != 0);
> -
> -	if (dbcr_iac_range(child) & DBCR_IAC12MODE)
> -		slot2_in_use = 1;
> -	if (dbcr_iac_range(child) & DBCR_IAC34MODE)
> -		slot4_in_use = 1;
> -
> -	if (bp_info->addr >= TASK_SIZE)
> -		return -EIO;
> -
> -	if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT) {
> -
> -		/* Make sure range is valid. */
> -		if (bp_info->addr2 >= TASK_SIZE)
> -			return -EIO;
> -
> -		/* We need a pair of IAC regsisters */
> -		if ((!slot1_in_use) && (!slot2_in_use)) {
> -			slot = 1;
> -			child->thread.debug.iac1 = bp_info->addr;
> -			child->thread.debug.iac2 = bp_info->addr2;
> -			child->thread.debug.dbcr0 |= DBCR0_IAC1;
> -			if (bp_info->addr_mode ==
> -					PPC_BREAKPOINT_MODE_RANGE_EXCLUSIVE)
> -				dbcr_iac_range(child) |= DBCR_IAC12X;
> -			else
> -				dbcr_iac_range(child) |= DBCR_IAC12I;
> -#if CONFIG_PPC_ADV_DEBUG_IACS > 2
> -		} else if ((!slot3_in_use) && (!slot4_in_use)) {
> -			slot = 3;
> -			child->thread.debug.iac3 = bp_info->addr;
> -			child->thread.debug.iac4 = bp_info->addr2;
> -			child->thread.debug.dbcr0 |= DBCR0_IAC3;
> -			if (bp_info->addr_mode ==
> -					PPC_BREAKPOINT_MODE_RANGE_EXCLUSIVE)
> -				dbcr_iac_range(child) |= DBCR_IAC34X;
> -			else
> -				dbcr_iac_range(child) |= DBCR_IAC34I;
> -#endif
> -		} else
> -			return -ENOSPC;
> -	} else {
> -		/* We only need one.  If possible leave a pair free in
> -		 * case a range is needed later
> -		 */
> -		if (!slot1_in_use) {
> -			/*
> -			 * Don't use iac1 if iac1-iac2 are free and either
> -			 * iac3 or iac4 (but not both) are free
> -			 */
> -			if (slot2_in_use || (slot3_in_use == slot4_in_use)) {
> -				slot = 1;
> -				child->thread.debug.iac1 = bp_info->addr;
> -				child->thread.debug.dbcr0 |= DBCR0_IAC1;
> -				goto out;
> -			}
> -		}
> -		if (!slot2_in_use) {
> -			slot = 2;
> -			child->thread.debug.iac2 = bp_info->addr;
> -			child->thread.debug.dbcr0 |= DBCR0_IAC2;
> -#if CONFIG_PPC_ADV_DEBUG_IACS > 2
> -		} else if (!slot3_in_use) {
> -			slot = 3;
> -			child->thread.debug.iac3 = bp_info->addr;
> -			child->thread.debug.dbcr0 |= DBCR0_IAC3;
> -		} else if (!slot4_in_use) {
> -			slot = 4;
> -			child->thread.debug.iac4 = bp_info->addr;
> -			child->thread.debug.dbcr0 |= DBCR0_IAC4;
> -#endif
> -		} else
> -			return -ENOSPC;
> -	}
> -out:
> -	child->thread.debug.dbcr0 |= DBCR0_IDM;
> -	child->thread.regs->msr |= MSR_DE;
> -
> -	return slot;
> -}
> -
> -static int del_instruction_bp(struct task_struct *child, int slot)
> -{
> -	switch (slot) {
> -	case 1:
> -		if ((child->thread.debug.dbcr0 & DBCR0_IAC1) == 0)
> -			return -ENOENT;
> -
> -		if (dbcr_iac_range(child) & DBCR_IAC12MODE) {
> -			/* address range - clear slots 1 & 2 */
> -			child->thread.debug.iac2 = 0;
> -			dbcr_iac_range(child) &= ~DBCR_IAC12MODE;
> -		}
> -		child->thread.debug.iac1 = 0;
> -		child->thread.debug.dbcr0 &= ~DBCR0_IAC1;
> -		break;
> -	case 2:
> -		if ((child->thread.debug.dbcr0 & DBCR0_IAC2) == 0)
> -			return -ENOENT;
> -
> -		if (dbcr_iac_range(child) & DBCR_IAC12MODE)
> -			/* used in a range */
> -			return -EINVAL;
> -		child->thread.debug.iac2 = 0;
> -		child->thread.debug.dbcr0 &= ~DBCR0_IAC2;
> -		break;
> -#if CONFIG_PPC_ADV_DEBUG_IACS > 2
> -	case 3:
> -		if ((child->thread.debug.dbcr0 & DBCR0_IAC3) == 0)
> -			return -ENOENT;
> -
> -		if (dbcr_iac_range(child) & DBCR_IAC34MODE) {
> -			/* address range - clear slots 3 & 4 */
> -			child->thread.debug.iac4 = 0;
> -			dbcr_iac_range(child) &= ~DBCR_IAC34MODE;
> -		}
> -		child->thread.debug.iac3 = 0;
> -		child->thread.debug.dbcr0 &= ~DBCR0_IAC3;
> -		break;
> -	case 4:
> -		if ((child->thread.debug.dbcr0 & DBCR0_IAC4) == 0)
> -			return -ENOENT;
> -
> -		if (dbcr_iac_range(child) & DBCR_IAC34MODE)
> -			/* Used in a range */
> -			return -EINVAL;
> -		child->thread.debug.iac4 = 0;
> -		child->thread.debug.dbcr0 &= ~DBCR0_IAC4;
> -		break;
> -#endif
> -	default:
> -		return -EINVAL;
> -	}
> -	return 0;
> -}
> -
> -static int set_dac(struct task_struct *child, struct ppc_hw_breakpoint *bp_info)
> -{
> -	int byte_enable =
> -		(bp_info->condition_mode >> PPC_BREAKPOINT_CONDITION_BE_SHIFT)
> -		& 0xf;
> -	int condition_mode =
> -		bp_info->condition_mode & PPC_BREAKPOINT_CONDITION_MODE;
> -	int slot;
> -
> -	if (byte_enable && (condition_mode == 0))
> -		return -EINVAL;
> -
> -	if (bp_info->addr >= TASK_SIZE)
> -		return -EIO;
> -
> -	if ((dbcr_dac(child) & (DBCR_DAC1R | DBCR_DAC1W)) == 0) {
> -		slot = 1;
> -		if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
> -			dbcr_dac(child) |= DBCR_DAC1R;
> -		if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
> -			dbcr_dac(child) |= DBCR_DAC1W;
> -		child->thread.debug.dac1 = (unsigned long)bp_info->addr;
> -#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
> -		if (byte_enable) {
> -			child->thread.debug.dvc1 =
> -				(unsigned long)bp_info->condition_value;
> -			child->thread.debug.dbcr2 |=
> -				((byte_enable << DBCR2_DVC1BE_SHIFT) |
> -				 (condition_mode << DBCR2_DVC1M_SHIFT));
> -		}
> -#endif
> -#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
> -	} else if (child->thread.debug.dbcr2 & DBCR2_DAC12MODE) {
> -		/* Both dac1 and dac2 are part of a range */
> -		return -ENOSPC;
> -#endif
> -	} else if ((dbcr_dac(child) & (DBCR_DAC2R | DBCR_DAC2W)) == 0) {
> -		slot = 2;
> -		if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
> -			dbcr_dac(child) |= DBCR_DAC2R;
> -		if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
> -			dbcr_dac(child) |= DBCR_DAC2W;
> -		child->thread.debug.dac2 = (unsigned long)bp_info->addr;
> -#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
> -		if (byte_enable) {
> -			child->thread.debug.dvc2 =
> -				(unsigned long)bp_info->condition_value;
> -			child->thread.debug.dbcr2 |=
> -				((byte_enable << DBCR2_DVC2BE_SHIFT) |
> -				 (condition_mode << DBCR2_DVC2M_SHIFT));
> -		}
> -#endif
> -	} else
> -		return -ENOSPC;
> -	child->thread.debug.dbcr0 |= DBCR0_IDM;
> -	child->thread.regs->msr |= MSR_DE;
> -
> -	return slot + 4;
> -}
> -
> -static int del_dac(struct task_struct *child, int slot)
> -{
> -	if (slot == 1) {
> -		if ((dbcr_dac(child) & (DBCR_DAC1R | DBCR_DAC1W)) == 0)
> -			return -ENOENT;
> -
> -		child->thread.debug.dac1 = 0;
> -		dbcr_dac(child) &= ~(DBCR_DAC1R | DBCR_DAC1W);
> -#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
> -		if (child->thread.debug.dbcr2 & DBCR2_DAC12MODE) {
> -			child->thread.debug.dac2 = 0;
> -			child->thread.debug.dbcr2 &= ~DBCR2_DAC12MODE;
> -		}
> -		child->thread.debug.dbcr2 &= ~(DBCR2_DVC1M | DBCR2_DVC1BE);
> -#endif
> -#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
> -		child->thread.debug.dvc1 = 0;
> -#endif
> -	} else if (slot == 2) {
> -		if ((dbcr_dac(child) & (DBCR_DAC2R | DBCR_DAC2W)) == 0)
> -			return -ENOENT;
> -
> -#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
> -		if (child->thread.debug.dbcr2 & DBCR2_DAC12MODE)
> -			/* Part of a range */
> -			return -EINVAL;
> -		child->thread.debug.dbcr2 &= ~(DBCR2_DVC2M | DBCR2_DVC2BE);
> -#endif
> -#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
> -		child->thread.debug.dvc2 = 0;
> -#endif
> -		child->thread.debug.dac2 = 0;
> -		dbcr_dac(child) &= ~(DBCR_DAC2R | DBCR_DAC2W);
> -	} else
> -		return -EINVAL;
> -
> -	return 0;
> -}
> -#endif /* CONFIG_PPC_ADV_DEBUG_REGS */
> -
> -#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
> -static int set_dac_range(struct task_struct *child,
> -			 struct ppc_hw_breakpoint *bp_info)
> -{
> -	int mode = bp_info->addr_mode & PPC_BREAKPOINT_MODE_MASK;
> -
> -	/* We don't allow range watchpoints to be used with DVC */
> -	if (bp_info->condition_mode)
> -		return -EINVAL;
> -
> -	/*
> -	 * Best effort to verify the address range.  The user/supervisor bits
> -	 * prevent trapping in kernel space, but let's fail on an obvious bad
> -	 * range.  The simple test on the mask is not fool-proof, and any
> -	 * exclusive range will spill over into kernel space.
> -	 */
> -	if (bp_info->addr >= TASK_SIZE)
> -		return -EIO;
> -	if (mode == PPC_BREAKPOINT_MODE_MASK) {
> -		/*
> -		 * dac2 is a bitmask.  Don't allow a mask that makes a
> -		 * kernel space address from a valid dac1 value
> -		 */
> -		if (~((unsigned long)bp_info->addr2) >= TASK_SIZE)
> -			return -EIO;
> -	} else {
> -		/*
> -		 * For range breakpoints, addr2 must also be a valid address
> -		 */
> -		if (bp_info->addr2 >= TASK_SIZE)
> -			return -EIO;
> -	}
> -
> -	if (child->thread.debug.dbcr0 &
> -	    (DBCR0_DAC1R | DBCR0_DAC1W | DBCR0_DAC2R | DBCR0_DAC2W))
> -		return -ENOSPC;
> -
> -	if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
> -		child->thread.debug.dbcr0 |= (DBCR0_DAC1R | DBCR0_IDM);
> -	if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
> -		child->thread.debug.dbcr0 |= (DBCR0_DAC1W | DBCR0_IDM);
> -	child->thread.debug.dac1 = bp_info->addr;
> -	child->thread.debug.dac2 = bp_info->addr2;
> -	if (mode == PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE)
> -		child->thread.debug.dbcr2  |= DBCR2_DAC12M;
> -	else if (mode == PPC_BREAKPOINT_MODE_RANGE_EXCLUSIVE)
> -		child->thread.debug.dbcr2  |= DBCR2_DAC12MX;
> -	else	/* PPC_BREAKPOINT_MODE_MASK */
> -		child->thread.debug.dbcr2  |= DBCR2_DAC12MM;
> -	child->thread.regs->msr |= MSR_DE;
> -
> -	return 5;
> -}
> -#endif /* CONFIG_PPC_ADV_DEBUG_DAC_RANGE */
> -
> -static long ppc_set_hwdebug(struct task_struct *child,
> -		     struct ppc_hw_breakpoint *bp_info)
> -{
> -#ifdef CONFIG_HAVE_HW_BREAKPOINT
> -	int len = 0;
> -	struct thread_struct *thread = &(child->thread);
> -	struct perf_event *bp;
> -	struct perf_event_attr attr;
> -#endif /* CONFIG_HAVE_HW_BREAKPOINT */
> -#ifndef CONFIG_PPC_ADV_DEBUG_REGS
> -	struct arch_hw_breakpoint brk;
> -#endif
> -
> -	if (bp_info->version != 1)
> -		return -ENOTSUPP;
> -#ifdef CONFIG_PPC_ADV_DEBUG_REGS
> -	/*
> -	 * Check for invalid flags and combinations
> -	 */
> -	if ((bp_info->trigger_type == 0) ||
> -	    (bp_info->trigger_type & ~(PPC_BREAKPOINT_TRIGGER_EXECUTE |
> -				       PPC_BREAKPOINT_TRIGGER_RW)) ||
> -	    (bp_info->addr_mode & ~PPC_BREAKPOINT_MODE_MASK) ||
> -	    (bp_info->condition_mode &
> -	     ~(PPC_BREAKPOINT_CONDITION_MODE |
> -	       PPC_BREAKPOINT_CONDITION_BE_ALL)))
> -		return -EINVAL;
> -#if CONFIG_PPC_ADV_DEBUG_DVCS == 0
> -	if (bp_info->condition_mode != PPC_BREAKPOINT_CONDITION_NONE)
> -		return -EINVAL;
> -#endif
> -
> -	if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_EXECUTE) {
> -		if ((bp_info->trigger_type != PPC_BREAKPOINT_TRIGGER_EXECUTE) ||
> -		    (bp_info->condition_mode != PPC_BREAKPOINT_CONDITION_NONE))
> -			return -EINVAL;
> -		return set_instruction_bp(child, bp_info);
> -	}
> -	if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_EXACT)
> -		return set_dac(child, bp_info);
> -
> -#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
> -	return set_dac_range(child, bp_info);
> -#else
> -	return -EINVAL;
> -#endif
> -#else /* !CONFIG_PPC_ADV_DEBUG_DVCS */
> -	/*
> -	 * We only support one data breakpoint
> -	 */
> -	if ((bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_RW) == 0 ||
> -	    (bp_info->trigger_type & ~PPC_BREAKPOINT_TRIGGER_RW) != 0 ||
> -	    bp_info->condition_mode != PPC_BREAKPOINT_CONDITION_NONE)
> -		return -EINVAL;
> -
> -	if ((unsigned long)bp_info->addr >= TASK_SIZE)
> -		return -EIO;
> -
> -	brk.address = bp_info->addr & ~HW_BREAKPOINT_ALIGN;
> -	brk.type = HW_BRK_TYPE_TRANSLATE;
> -	brk.len = DABR_MAX_LEN;
> -	if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
> -		brk.type |= HW_BRK_TYPE_READ;
> -	if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
> -		brk.type |= HW_BRK_TYPE_WRITE;
> -#ifdef CONFIG_HAVE_HW_BREAKPOINT
> -	if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE)
> -		len = bp_info->addr2 - bp_info->addr;
> -	else if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_EXACT)
> -		len = 1;
> -	else
> -		return -EINVAL;
> -	bp = thread->ptrace_bps[0];
> -	if (bp)
> -		return -ENOSPC;
> -
> -	/* Create a new breakpoint request if one doesn't exist already */
> -	hw_breakpoint_init(&attr);
> -	attr.bp_addr = (unsigned long)bp_info->addr;
> -	attr.bp_len = len;
> -	arch_bp_generic_fields(brk.type, &attr.bp_type);
> -
> -	thread->ptrace_bps[0] = bp = register_user_hw_breakpoint(&attr,
> -					       ptrace_triggered, NULL, child);
> -	if (IS_ERR(bp)) {
> -		thread->ptrace_bps[0] = NULL;
> -		return PTR_ERR(bp);
> -	}
> -
> -	return 1;
> -#endif /* CONFIG_HAVE_HW_BREAKPOINT */
> -
> -	if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT)
> -		return -EINVAL;
> -
> -	if (child->thread.hw_brk.address)
> -		return -ENOSPC;
> -
> -	if (!ppc_breakpoint_available())
> -		return -ENODEV;
> -
> -	child->thread.hw_brk = brk;
> -
> -	return 1;
> -#endif /* !CONFIG_PPC_ADV_DEBUG_DVCS */
> -}
> -
> -static long ppc_del_hwdebug(struct task_struct *child, long data)
> -{
> -#ifdef CONFIG_HAVE_HW_BREAKPOINT
> -	int ret = 0;
> -	struct thread_struct *thread = &(child->thread);
> -	struct perf_event *bp;
> -#endif /* CONFIG_HAVE_HW_BREAKPOINT */
> -#ifdef CONFIG_PPC_ADV_DEBUG_REGS
> -	int rc;
> -
> -	if (data <= 4)
> -		rc = del_instruction_bp(child, (int)data);
> -	else
> -		rc = del_dac(child, (int)data - 4);
> -
> -	if (!rc) {
> -		if (!DBCR_ACTIVE_EVENTS(child->thread.debug.dbcr0,
> -					child->thread.debug.dbcr1)) {
> -			child->thread.debug.dbcr0 &= ~DBCR0_IDM;
> -			child->thread.regs->msr &= ~MSR_DE;
> -		}
> -	}
> -	return rc;
> -#else
> -	if (data != 1)
> -		return -EINVAL;
> -
> -#ifdef CONFIG_HAVE_HW_BREAKPOINT
> -	bp = thread->ptrace_bps[0];
> -	if (bp) {
> -		unregister_hw_breakpoint(bp);
> -		thread->ptrace_bps[0] = NULL;
> -	} else
> -		ret = -ENOENT;
> -	return ret;
> -#else /* CONFIG_HAVE_HW_BREAKPOINT */
> -	if (child->thread.hw_brk.address == 0)
> -		return -ENOENT;
> -
> -	child->thread.hw_brk.address = 0;
> -	child->thread.hw_brk.type = 0;
> -#endif /* CONFIG_HAVE_HW_BREAKPOINT */
> -
> -	return 0;
> -#endif
> -}
> -
>  long arch_ptrace(struct task_struct *child, long request,
>  		 unsigned long addr, unsigned long data)
>  {
> -- 
> 2.25.0