[net-next-2.6.git] / arch / cris / arch-v32 / kernel / ptrace.c

/*
 * Copyright (C) 2000-2007, Axis Communications AB.
 */

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/signal.h>
#include <linux/security.h>

#include <asm/uaccess.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/processor.h>
#include <arch/hwregs/supp_reg.h>

/*
 * Determines which bits in CCS the user has access to.
 * 1 = access, 0 = no access.
 */
#define CCS_MASK 0x00087c00     /* SXNZVC */

#define SBIT_USER (1 << (S_CCS_BITNR + CCS_SHIFT))

static int put_debugreg(long pid, unsigned int regno, long data);
static long get_debugreg(long pid, unsigned int regno);
static unsigned long get_pseudo_pc(struct task_struct *child);
void deconfigure_bp(long pid);

extern unsigned long cris_signal_return_page;

/*
 * Get contents of register REGNO in task TASK.
 */
long get_reg(struct task_struct *task, unsigned int regno)
{
	/* USP is a special case, it's not in the pt_regs struct but
	 * in the tasks thread struct
	 */
	unsigned long ret;

	if (regno <= PT_EDA)
		ret = ((unsigned long *)task_pt_regs(task))[regno];
	else if (regno == PT_USP)
		ret = task->thread.usp;
	else if (regno == PT_PPC)
		ret = get_pseudo_pc(task);
	else if (regno <= PT_MAX)
		ret = get_debugreg(task->pid, regno);
	else
		ret = 0;

	return ret;
}

/*
 * Write contents of register REGNO in task TASK.
 */
int put_reg(struct task_struct *task, unsigned int regno, unsigned long data)
{
	if (regno <= PT_EDA)
		((unsigned long *)task_pt_regs(task))[regno] = data;
	else if (regno == PT_USP)
		task->thread.usp = data;
	else if (regno == PT_PPC) {
		/* Write pseudo-PC to ERP only if changed. */
		if (data != get_pseudo_pc(task))
			task_pt_regs(task)->erp = data;
	} else if (regno <= PT_MAX)
		return put_debugreg(task->pid, regno, data);
	else
		return -1;
	return 0;
}

void user_enable_single_step(struct task_struct *child)
{
	unsigned long tmp;

	/*
	 * Set up SPC if not set already (in which case we have no other
	 * choice but to trust it).
	 */
	if (!get_reg(child, PT_SPC)) {
		/* In case we're stopped in a delay slot. */
		tmp = get_reg(child, PT_ERP) & ~1;
		put_reg(child, PT_SPC, tmp);
	}
	tmp = get_reg(child, PT_CCS) | SBIT_USER;
	put_reg(child, PT_CCS, tmp);
}

void user_disable_single_step(struct task_struct *child)
{
	put_reg(child, PT_SPC, 0);

	if (!get_debugreg(child->pid, PT_BP_CTRL)) {
		unsigned long tmp;
		/* If no h/w bp configured, disable S bit. */
		tmp = get_reg(child, PT_CCS) & ~SBIT_USER;
		put_reg(child, PT_CCS, tmp);
	}
}

/*
 * Called by kernel/ptrace.c when detaching.
 *
 * Make sure the single step bit is not set.
 */
void
ptrace_disable(struct task_struct *child)
{
	unsigned long tmp;

	/* Deconfigure SPC and S-bit. */
	user_disable_single_step(child);
	put_reg(child, PT_SPC, 0);

	/* Deconfigure any watchpoints associated with the child. */
	deconfigure_bp(child->pid);
}


long arch_ptrace(struct task_struct *child, long request,
		 unsigned long addr, unsigned long data)
{
	int ret;
	unsigned int regno = addr >> 2;
	unsigned long __user *datap = (unsigned long __user *)data;

	switch (request) {
		/* Read word at location address. */
		case PTRACE_PEEKTEXT:
		case PTRACE_PEEKDATA: {
			unsigned long tmp;
			int copied;

			ret = -EIO;

			/* The signal trampoline page is outside the normal user-addressable
			 * space but still accessible. This is hack to make it possible to
			 * access the signal handler code in GDB.
			 */
			if ((addr & PAGE_MASK) == cris_signal_return_page) {
				/* The trampoline page is globally mapped, no page table to traverse.*/
				tmp = *(unsigned long*)addr;
			} else {
				copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);

				if (copied != sizeof(tmp))
					break;
			}

			ret = put_user(tmp,datap);
			break;
		}

		/* Read the word at location address in the USER area. */
		case PTRACE_PEEKUSR: {
			unsigned long tmp;

			ret = -EIO;
			if ((addr & 3) || regno > PT_MAX)
				break;

			tmp = get_reg(child, regno);
			ret = put_user(tmp, datap);
			break;
		}

		/* Write the word at location address. */
		case PTRACE_POKETEXT:
		case PTRACE_POKEDATA:
			ret = generic_ptrace_pokedata(child, addr, data);
			break;

		/* Write the word at location address in the USER area. */
		case PTRACE_POKEUSR:
			ret = -EIO;
			if ((addr & 3) || regno > PT_MAX)
				break;

			if (regno == PT_CCS) {
				/* don't allow the tracing process to change stuff like
				 * interrupt enable, kernel/user bit, dma enables etc.
				 */
				data &= CCS_MASK;
				data |= get_reg(child, PT_CCS) & ~CCS_MASK;
			}
			if (put_reg(child, regno, data))
				break;
			ret = 0;
			break;

		/* Get all GP registers from the child. */
		case PTRACE_GETREGS: {
			int i;
			unsigned long tmp;

			for (i = 0; i <= PT_MAX; i++) {
				tmp = get_reg(child, i);

				if (put_user(tmp, datap)) {
					ret = -EFAULT;
					goto out_tsk;
				}

				datap++;
			}

			ret = 0;
			break;
		}

		/* Set all GP registers in the child. */
		case PTRACE_SETREGS: {
			int i;
			unsigned long tmp;

			for (i = 0; i <= PT_MAX; i++) {
				if (get_user(tmp, datap)) {
					ret = -EFAULT;
					goto out_tsk;
				}

				if (i == PT_CCS) {
					tmp &= CCS_MASK;
					tmp |= get_reg(child, PT_CCS) & ~CCS_MASK;
				}

				put_reg(child, i, tmp);
				datap++;
			}

			ret = 0;
			break;
		}

		default:
			ret = ptrace_request(child, request, addr, data);
			break;
	}

out_tsk:
	return ret;
}

void do_syscall_trace(void)
{
	if (!test_thread_flag(TIF_SYSCALL_TRACE))
		return;

	if (!(current->ptrace & PT_PTRACED))
		return;

	/* the 0x80 provides a way for the tracing parent to distinguish
	   between a syscall stop and SIGTRAP delivery */
	ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
				 ? 0x80 : 0));

	/*
	 * This isn't the same as continuing with a signal, but it will do for
	 * normal use.
	 */
	if (current->exit_code) {
		send_sig(current->exit_code, current, 1);
		current->exit_code = 0;
	}
}

/* Returns the size of an instruction that has a delay slot. */

static int insn_size(struct task_struct *child, unsigned long pc)
{
  unsigned long opcode;
  int copied;
  int opsize = 0;

  /* Read the opcode at pc (do what PTRACE_PEEKTEXT would do). */
  copied = access_process_vm(child, pc, &opcode, sizeof(opcode), 0);
  if (copied != sizeof(opcode))
    return 0;

  switch ((opcode & 0x0f00) >> 8) {
  case 0x0:
  case 0x9:
  case 0xb:
	  opsize = 2;
	  break;
  case 0xe:
  case 0xf:
	  opsize = 6;
	  break;
  case 0xd:
	  /* Could be 4 or 6; check more bits. */
	  if ((opcode & 0xff) == 0xff)
		  opsize = 4;
	  else
		  opsize = 6;
	  break;
  default:
	  panic("ERROR: Couldn't find size of opcode 0x%lx at 0x%lx\n",
		opcode, pc);
  }

  return opsize;
}

static unsigned long get_pseudo_pc(struct task_struct *child)
{
	/* Default value for PC is ERP. */
	unsigned long pc = get_reg(child, PT_ERP);

	if (pc & 0x1) {
		unsigned long spc = get_reg(child, PT_SPC);
		/* Delay slot bit set. Report as stopped on proper
		   instruction. */
		if (spc) {
			/* Rely on SPC if set. FIXME: We might want to check
			   that EXS indicates we stopped due to a single-step
			   exception. */
			pc = spc;
		} else {
			/* Calculate the PC from the size of the instruction
			   that the delay slot we're in belongs to. */
			pc += insn_size(child, pc & ~1) - 1;
		}
	}
	return pc;
}

static long bp_owner = 0;

/* Reachable from exit_thread in signal.c, so not static. */
void deconfigure_bp(long pid)
{
	int bp;

	/* Only deconfigure if the pid is the owner. */
	if (bp_owner != pid)
		return;

	for (bp = 0; bp < 6; bp++) {
		unsigned long tmp;
		/* Deconfigure start and end address (also gets rid of ownership). */
		put_debugreg(pid, PT_BP + 3 + (bp * 2), 0);
		put_debugreg(pid, PT_BP + 4 + (bp * 2), 0);

		/* Deconfigure relevant bits in control register. */
		tmp = get_debugreg(pid, PT_BP_CTRL) & ~(3 << (2 + (bp * 4)));
		put_debugreg(pid, PT_BP_CTRL, tmp);
	}
	/* No owner now. */
	bp_owner = 0;
}

static int put_debugreg(long pid, unsigned int regno, long data)
{
	int ret = 0;
	register int old_srs;

#ifdef CONFIG_ETRAX_KGDB
	/* Ignore write, but pretend it was ok if value is 0
	   (we don't want POKEUSR/SETREGS failing unnessecarily). */
	return (data == 0) ? ret : -1;
#endif

	/* Simple owner management. */
	if (!bp_owner)
		bp_owner = pid;
	else if (bp_owner != pid) {
		/* Ignore write, but pretend it was ok if value is 0
		   (we don't want POKEUSR/SETREGS failing unnessecarily). */
		return (data == 0) ? ret : -1;
	}

	/* Remember old SRS. */
	SPEC_REG_RD(SPEC_REG_SRS, old_srs);
	/* Switch to BP bank. */
	SUPP_BANK_SEL(BANK_BP);

	switch (regno - PT_BP) {
	case 0:
		SUPP_REG_WR(0, data); break;
	case 1:
	case 2:
		if (data)
			ret = -1;
		break;
	case 3:
		SUPP_REG_WR(3, data); break;
	case 4:
		SUPP_REG_WR(4, data); break;
	case 5:
		SUPP_REG_WR(5, data); break;
	case 6:
		SUPP_REG_WR(6, data); break;
	case 7:
		SUPP_REG_WR(7, data); break;
	case 8:
		SUPP_REG_WR(8, data); break;
	case 9:
		SUPP_REG_WR(9, data); break;
	case 10:
		SUPP_REG_WR(10, data); break;
	case 11:
		SUPP_REG_WR(11, data); break;
	case 12:
		SUPP_REG_WR(12, data); break;
	case 13:
		SUPP_REG_WR(13, data); break;
	case 14:
		SUPP_REG_WR(14, data); break;
	default:
		ret = -1;
		break;
	}

	/* Restore SRS. */
	SPEC_REG_WR(SPEC_REG_SRS, old_srs);
	/* Just for show. */
	NOP();
	NOP();
	NOP();

	return ret;
}

static long get_debugreg(long pid, unsigned int regno)
{
	register int old_srs;
	register long data;

	if (pid != bp_owner) {
		return 0;
	}

	/* Remember old SRS. */
	SPEC_REG_RD(SPEC_REG_SRS, old_srs);
	/* Switch to BP bank. */
	SUPP_BANK_SEL(BANK_BP);

	switch (regno - PT_BP) {
	case 0:
		SUPP_REG_RD(0, data); break;
	case 1:
	case 2:
		/* error return value? */
		data = 0;
		break;
	case 3:
		SUPP_REG_RD(3, data); break;
	case 4:
		SUPP_REG_RD(4, data); break;
	case 5:
		SUPP_REG_RD(5, data); break;
	case 6:
		SUPP_REG_RD(6, data); break;
	case 7:
		SUPP_REG_RD(7, data); break;
	case 8:
		SUPP_REG_RD(8, data); break;
	case 9:
		SUPP_REG_RD(9, data); break;
	case 10:
		SUPP_REG_RD(10, data); break;
	case 11:
		SUPP_REG_RD(11, data); break;
	case 12:
		SUPP_REG_RD(12, data); break;
	case 13:
		SUPP_REG_RD(13, data); break;
	case 14:
		SUPP_REG_RD(14, data); break;
	default:
		/* error return value? */
		data = 0;
	}

	/* Restore SRS. */
	SPEC_REG_WR(SPEC_REG_SRS, old_srs);
	/* Just for show. */
	NOP();
	NOP();
	NOP();

	return data;
}
Commit	Line	Data
51533b61	1	/*
54ab4d72	2	* Copyright (C) 2000-2007, Axis Communications AB.
51533b61 MS	3	*/
	4
	5	#include <linux/kernel.h>
	6	#include <linux/sched.h>
	7	#include <linux/mm.h>
	8	#include <linux/smp.h>
51533b61 MS	9	#include <linux/errno.h>
	10	#include <linux/ptrace.h>
	11	#include <linux/user.h>
	12	#include <linux/signal.h>
	13	#include <linux/security.h>
	14
	15	#include <asm/uaccess.h>
	16	#include <asm/page.h>
	17	#include <asm/pgtable.h>
	18	#include <asm/system.h>
	19	#include <asm/processor.h>
556dcee7	20	#include <arch/hwregs/supp_reg.h>
51533b61 MS	21
	22	/*
	23	* Determines which bits in CCS the user has access to.
	24	* 1 = access, 0 = no access.
	25	*/
	26	#define CCS_MASK 0x00087c00 /* SXNZVC */
	27
	28	#define SBIT_USER (1 << (S_CCS_BITNR + CCS_SHIFT))
	29
	30	static int put_debugreg(long pid, unsigned int regno, long data);
	31	static long get_debugreg(long pid, unsigned int regno);
	32	static unsigned long get_pseudo_pc(struct task_struct *child);
	33	void deconfigure_bp(long pid);
	34
	35	extern unsigned long cris_signal_return_page;
	36
	37	/*
	38	* Get contents of register REGNO in task TASK.
	39	*/
	40	long get_reg(struct task_struct *task, unsigned int regno)
	41	{
	42	/* USP is a special case, it's not in the pt_regs struct but
	43	* in the tasks thread struct
	44	*/
	45	unsigned long ret;
	46
	47	if (regno <= PT_EDA)
95ca0dc6	48	ret = ((unsigned long *)task_pt_regs(task))[regno];
51533b61 MS	49	else if (regno == PT_USP)
	50	ret = task->thread.usp;
	51	else if (regno == PT_PPC)
	52	ret = get_pseudo_pc(task);
	53	else if (regno <= PT_MAX)
	54	ret = get_debugreg(task->pid, regno);
	55	else
	56	ret = 0;
	57
	58	return ret;
	59	}
	60
	61	/*
	62	* Write contents of register REGNO in task TASK.
	63	*/
	64	int put_reg(struct task_struct *task, unsigned int regno, unsigned long data)
	65	{
	66	if (regno <= PT_EDA)
95ca0dc6	67	((unsigned long *)task_pt_regs(task))[regno] = data;
51533b61 MS	68	else if (regno == PT_USP)
	69	task->thread.usp = data;
	70	else if (regno == PT_PPC) {
	71	/* Write pseudo-PC to ERP only if changed. */
	72	if (data != get_pseudo_pc(task))
95ca0dc6	73	task_pt_regs(task)->erp = data;
51533b61 MS	74	} else if (regno <= PT_MAX)
	75	return put_debugreg(task->pid, regno, data);
	76	else
	77	return -1;
	78	return 0;
	79	}
	80
290ba3ae CH	81	void user_enable_single_step(struct task_struct *child)
	82	{
	83	unsigned long tmp;
	84
	85	/*
	86	* Set up SPC if not set already (in which case we have no other
	87	* choice but to trust it).
	88	*/
	89	if (!get_reg(child, PT_SPC)) {
	90	/* In case we're stopped in a delay slot. */
	91	tmp = get_reg(child, PT_ERP) & ~1;
	92	put_reg(child, PT_SPC, tmp);
	93	}
	94	tmp = get_reg(child, PT_CCS) \| SBIT_USER;
	95	put_reg(child, PT_CCS, tmp);
	96	}
	97
	98	void user_disable_single_step(struct task_struct *child)
	99	{
	100	put_reg(child, PT_SPC, 0);
	101
	102	if (!get_debugreg(child->pid, PT_BP_CTRL)) {
	103	unsigned long tmp;
	104	/* If no h/w bp configured, disable S bit. */
	105	tmp = get_reg(child, PT_CCS) & ~SBIT_USER;
	106	put_reg(child, PT_CCS, tmp);
	107	}
	108	}
	109
51533b61 MS	110	/*
	111	* Called by kernel/ptrace.c when detaching.
	112	*
	113	* Make sure the single step bit is not set.
	114	*/
	115	void
	116	ptrace_disable(struct task_struct *child)
	117	{
	118	unsigned long tmp;
	119
	120	/* Deconfigure SPC and S-bit. */
290ba3ae	121	user_disable_single_step(child);
51533b61 MS	122	put_reg(child, PT_SPC, 0);
	123
	124	/* Deconfigure any watchpoints associated with the child. */
	125	deconfigure_bp(child->pid);
	126	}
	127
	128
9b05a69e NK	129	long arch_ptrace(struct task_struct *child, long request,
9b05a69e NK	130	unsigned long addr, unsigned long data)
51533b61	131	{
51533b61	132	int ret;
475a4b81	133	unsigned int regno = addr >> 2;
51533b61 MS	134	unsigned long __user datap = (unsigned long __user )data;
51533b61 MS	135
51533b61 MS	136	switch (request) {
	137	/* Read word at location address. */
	138	case PTRACE_PEEKTEXT:
	139	case PTRACE_PEEKDATA: {
	140	unsigned long tmp;
	141	int copied;
	142
	143	ret = -EIO;
	144
	145	/* The signal trampoline page is outside the normal user-addressable
	146	* space but still accessible. This is hack to make it possible to
	147	* access the signal handler code in GDB.
	148	*/
	149	if ((addr & PAGE_MASK) == cris_signal_return_page) {
	150	/* The trampoline page is globally mapped, no page table to traverse.*/
	151	tmp = (unsigned long)addr;
	152	} else {
	153	copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
	154
	155	if (copied != sizeof(tmp))
	156	break;
	157	}
	158
	159	ret = put_user(tmp,datap);
	160	break;
	161	}
	162
	163	/* Read the word at location address in the USER area. */
	164	case PTRACE_PEEKUSR: {
	165	unsigned long tmp;
	166
	167	ret = -EIO;
475a4b81	168	if ((addr & 3) \|\| regno > PT_MAX)
51533b61 MS	169	break;
51533b61 MS	170
475a4b81	171	tmp = get_reg(child, regno);
51533b61 MS	172	ret = put_user(tmp, datap);
	173	break;
	174	}
	175
	176	/* Write the word at location address. */
	177	case PTRACE_POKETEXT:
	178	case PTRACE_POKEDATA:
f284ce72	179	ret = generic_ptrace_pokedata(child, addr, data);
51533b61 MS	180	break;
51533b61 MS	181
54ab4d72	182	/* Write the word at location address in the USER area. */
51533b61 MS	183	case PTRACE_POKEUSR:
51533b61 MS	184	ret = -EIO;
475a4b81	185	if ((addr & 3) \|\| regno > PT_MAX)
51533b61 MS	186	break;
51533b61 MS	187
475a4b81	188	if (regno == PT_CCS) {
51533b61 MS	189	/* don't allow the tracing process to change stuff like
	190	* interrupt enable, kernel/user bit, dma enables etc.
	191	*/
	192	data &= CCS_MASK;
	193	data \|= get_reg(child, PT_CCS) & ~CCS_MASK;
	194	}
475a4b81	195	if (put_reg(child, regno, data))
51533b61 MS	196	break;
	197	ret = 0;
	198	break;
	199
51533b61 MS	200	/* Get all GP registers from the child. */
51533b61 MS	201	case PTRACE_GETREGS: {
54ab4d72	202	int i;
51533b61 MS	203	unsigned long tmp;
	204
	205	for (i = 0; i <= PT_MAX; i++) {
	206	tmp = get_reg(child, i);
	207
	208	if (put_user(tmp, datap)) {
	209	ret = -EFAULT;
	210	goto out_tsk;
	211	}
	212
	213	datap++;
	214	}
	215
	216	ret = 0;
	217	break;
	218	}
	219
	220	/* Set all GP registers in the child. */
	221	case PTRACE_SETREGS: {
	222	int i;
	223	unsigned long tmp;
	224
	225	for (i = 0; i <= PT_MAX; i++) {
	226	if (get_user(tmp, datap)) {
	227	ret = -EFAULT;
	228	goto out_tsk;
	229	}
	230
	231	if (i == PT_CCS) {
	232	tmp &= CCS_MASK;
	233	tmp \|= get_reg(child, PT_CCS) & ~CCS_MASK;
	234	}
	235
	236	put_reg(child, i, tmp);
	237	datap++;
	238	}
	239
	240	ret = 0;
	241	break;
	242	}
	243
	244	default:
	245	ret = ptrace_request(child, request, addr, data);
	246	break;
	247	}
481bed45	248
54ab4d72	249	out_tsk:
51533b61 MS	250	return ret;
	251	}
	252
	253	void do_syscall_trace(void)
	254	{
	255	if (!test_thread_flag(TIF_SYSCALL_TRACE))
	256	return;
	257
	258	if (!(current->ptrace & PT_PTRACED))
	259	return;
	260
	261	/* the 0x80 provides a way for the tracing parent to distinguish
	262	between a syscall stop and SIGTRAP delivery */
	263	ptrace_notify(SIGTRAP \| ((current->ptrace & PT_TRACESYSGOOD)
	264	? 0x80 : 0));
	265
	266	/*
	267	* This isn't the same as continuing with a signal, but it will do for
	268	* normal use.
	269	*/
	270	if (current->exit_code) {
	271	send_sig(current->exit_code, current, 1);
	272	current->exit_code = 0;
	273	}
	274	}
	275
	276	/* Returns the size of an instruction that has a delay slot. */
	277
	278	static int insn_size(struct task_struct *child, unsigned long pc)
	279	{
	280	unsigned long opcode;
	281	int copied;
	282	int opsize = 0;
	283
	284	/* Read the opcode at pc (do what PTRACE_PEEKTEXT would do). */
	285	copied = access_process_vm(child, pc, &opcode, sizeof(opcode), 0);
	286	if (copied != sizeof(opcode))
	287	return 0;
	288
	289	switch ((opcode & 0x0f00) >> 8) {
	290	case 0x0:
	291	case 0x9:
	292	case 0xb:
	293	opsize = 2;
	294	break;
	295	case 0xe:
	296	case 0xf:
	297	opsize = 6;
	298	break;
	299	case 0xd:
	300	/* Could be 4 or 6; check more bits. */
	301	if ((opcode & 0xff) == 0xff)
	302	opsize = 4;
	303	else
	304	opsize = 6;
	305	break;
	306	default:
	307	panic("ERROR: Couldn't find size of opcode 0x%lx at 0x%lx\n",
	308	opcode, pc);
	309	}
	310
	311	return opsize;
	312	}
	313
314	static unsigned long get_pseudo_pc(struct task_struct *child)
315	{
316	/* Default value for PC is ERP. */
317	unsigned long pc = get_reg(child, PT_ERP);
318
319	if (pc & 0x1) {
320	unsigned long spc = get_reg(child, PT_SPC);
321	/* Delay slot bit set. Report as stopped on proper
322	instruction. */
323	if (spc) {
324	/* Rely on SPC if set. FIXME: We might want to check
325	that EXS indicates we stopped due to a single-step
326	exception. */
327	pc = spc;
328	} else {
329	/* Calculate the PC from the size of the instruction
330	that the delay slot we're in belongs to. */
331	pc += insn_size(child, pc & ~1) - 1;
332	}
333	}
334	return pc;
335	}
336
337	static long bp_owner = 0;
338
339	/* Reachable from exit_thread in signal.c, so not static. */
340	void deconfigure_bp(long pid)
341	{
342	int bp;
343
344	/* Only deconfigure if the pid is the owner. */
345	if (bp_owner != pid)
346	return;
347
348	for (bp = 0; bp < 6; bp++) {
349	unsigned long tmp;
350	/* Deconfigure start and end address (also gets rid of ownership). */
351	put_debugreg(pid, PT_BP + 3 + (bp * 2), 0);
352	put_debugreg(pid, PT_BP + 4 + (bp * 2), 0);
353
354	/* Deconfigure relevant bits in control register. */
355	tmp = get_debugreg(pid, PT_BP_CTRL) & ~(3 << (2 + (bp * 4)));
356	put_debugreg(pid, PT_BP_CTRL, tmp);
357	}
358	/* No owner now. */
359	bp_owner = 0;
360	}
361
362	static int put_debugreg(long pid, unsigned int regno, long data)
363	{
364	int ret = 0;
365	register int old_srs;
366
367	#ifdef CONFIG_ETRAX_KGDB
368	/* Ignore write, but pretend it was ok if value is 0
369	(we don't want POKEUSR/SETREGS failing unnessecarily). */
370	return (data == 0) ? ret : -1;
371	#endif
372
373	/* Simple owner management. */
374	if (!bp_owner)
375	bp_owner = pid;
376	else if (bp_owner != pid) {
377	/* Ignore write, but pretend it was ok if value is 0
378	(we don't want POKEUSR/SETREGS failing unnessecarily). */
379	return (data == 0) ? ret : -1;
380	}
381
382	/* Remember old SRS. */
383	SPEC_REG_RD(SPEC_REG_SRS, old_srs);
384	/* Switch to BP bank. */
385	SUPP_BANK_SEL(BANK_BP);
386
387	switch (regno - PT_BP) {
388	case 0:
389	SUPP_REG_WR(0, data); break;
390	case 1:
391	case 2:
392	if (data)
393	ret = -1;
394	break;
395	case 3:
396	SUPP_REG_WR(3, data); break;
397	case 4:
398	SUPP_REG_WR(4, data); break;
399	case 5:
400	SUPP_REG_WR(5, data); break;
401	case 6:
402	SUPP_REG_WR(6, data); break;
403	case 7:
404	SUPP_REG_WR(7, data); break;
405	case 8:
406	SUPP_REG_WR(8, data); break;
407	case 9:
408	SUPP_REG_WR(9, data); break;
409	case 10:
410	SUPP_REG_WR(10, data); break;
411	case 11:
412	SUPP_REG_WR(11, data); break;
413	case 12:
414	SUPP_REG_WR(12, data); break;
415	case 13:
416	SUPP_REG_WR(13, data); break;
417	case 14:
418	SUPP_REG_WR(14, data); break;
419	default:
420	ret = -1;
421	break;
422	}
423
424	/* Restore SRS. */
425	SPEC_REG_WR(SPEC_REG_SRS, old_srs);
426	/* Just for show. */
427	NOP();
428	NOP();
429	NOP();
430
431	return ret;
432	}
433
434	static long get_debugreg(long pid, unsigned int regno)
435	{
436	register int old_srs;
437	register long data;
438
439	if (pid != bp_owner) {
440	return 0;
441	}
442
443	/* Remember old SRS. */
444	SPEC_REG_RD(SPEC_REG_SRS, old_srs);
445	/* Switch to BP bank. */
446	SUPP_BANK_SEL(BANK_BP);
447
448	switch (regno - PT_BP) {
449	case 0:
450	SUPP_REG_RD(0, data); break;
451	case 1:
452	case 2:
453	/* error return value? */
454	data = 0;
455	break;
456	case 3:
457	SUPP_REG_RD(3, data); break;
458	case 4:
459	SUPP_REG_RD(4, data); break;
460	case 5:
461	SUPP_REG_RD(5, data); break;
462	case 6:
463	SUPP_REG_RD(6, data); break;
464	case 7:
465	SUPP_REG_RD(7, data); break;
466	case 8:
467	SUPP_REG_RD(8, data); break;
468	case 9:
469	SUPP_REG_RD(9, data); break;
470	case 10:
471	SUPP_REG_RD(10, data); break;
472	case 11:
473	SUPP_REG_RD(11, data); break;
474	case 12:
475	SUPP_REG_RD(12, data); break;
476	case 13:
477	SUPP_REG_RD(13, data); break;
478	case 14:
479	SUPP_REG_RD(14, data); break;
480	default:
481	/* error return value? */
482	data = 0;
483	}
484
485	/* Restore SRS. */
486	SPEC_REG_WR(SPEC_REG_SRS, old_srs);
487	/* Just for show. */
488	NOP();
489	NOP();
490	NOP();
491
492	return data;
493	}