powerpc/booke: Add support for advanced debug registers

powerpc/booke: Add support for advanced debug registers

From: Dave Kleikamp <shaggy@linux.vnet.ibm.com>

Based on patches originally written by Torez Smith.

This patch defines context switch and trap related functionality
for BookE specific Debug Registers. It adds support to ptrace()
for setting and getting BookE related Debug Registers

Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Torez Smith  <lnxtorez@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Gibson <dwg@au1.ibm.com>
Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Sergio Durigan Junior <sergiodj@br.ibm.com>
Cc: Thiago Jung Bauermann <bauerman@br.ibm.com>
Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

6 files changed, 582 insertions, 72 deletions

diff --git a/arch/powerpc/include/asm/system.h b/arch/powerpc/include/asm/system.h
index aa59f5b..a6297c6 100644
--- a/arch/powerpc/include/asm/system.h
+++ b/arch/powerpc/include/asm/system.h
@@ -112,8 +112,13 @@ static inline int debugger_fault_handler(struct pt_regs *regs) { return 0; }
 #endif
 
 extern int set_dabr(unsigned long dabr);
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+extern void do_send_trap(struct pt_regs *regs, unsigned long address,
+			 unsigned long error_code, int signal_code, int brkpt);
+#else
 extern void do_dabr(struct pt_regs *regs, unsigned long address,
 		    unsigned long error_code);
+#endif
 extern void print_backtrace(unsigned long *);
 extern void show_regs(struct pt_regs * regs);
 extern void flush_instruction_cache(void);
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 9be77e3..e4d71ce 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -245,6 +245,24 @@ void discard_lazy_cpu_state(void)
 }
 #endif /* CONFIG_SMP */
 
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+void do_send_trap(struct pt_regs *regs, unsigned long address,
+		  unsigned long error_code, int signal_code, int breakpt)
+{
+	siginfo_t info;
+
+	if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
+			11, SIGSEGV) == NOTIFY_STOP)
+		return;
+
+	/* Deliver the signal to userspace */
+	info.si_signo = SIGTRAP;
+	info.si_errno = breakpt;	/* breakpoint or watchpoint id */
+	info.si_code = signal_code;
+	info.si_addr = (void __user *)address;
+	force_sig_info(SIGTRAP, &info, current);
+}
+#else	/* !CONFIG_PPC_ADV_DEBUG_REGS */
 void do_dabr(struct pt_regs *regs, unsigned long address,
 		    unsigned long error_code)
 {
@@ -257,12 +275,6 @@ void do_dabr(struct pt_regs *regs, unsigned long address,
 	if (debugger_dabr_match(regs))
 		return;
 
-	/* Clear the DAC and struct entries.  One shot trigger */
-#ifdef CONFIG_PPC_ADV_DEBUG_REGS
-	mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~(DBSR_DAC1R | DBSR_DAC1W
-							| DBCR0_IDM));
-#endif
-
 	/* Clear the DABR */
 	set_dabr(0);
 
@@ -273,9 +285,82 @@ void do_dabr(struct pt_regs *regs, unsigned long address,
 	info.si_addr = (void __user *)address;
 	force_sig_info(SIGTRAP, &info, current);
 }
+#endif	/* CONFIG_PPC_ADV_DEBUG_REGS */
 
 static DEFINE_PER_CPU(unsigned long, current_dabr);
 
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+/*
+ * Set the debug registers back to their default "safe" values.
+ */
+static void set_debug_reg_defaults(struct thread_struct *thread)
+{
+	thread->iac1 = thread->iac2 = 0;
+#if CONFIG_PPC_ADV_DEBUG_IACS > 2
+	thread->iac3 = thread->iac4 = 0;
+#endif
+	thread->dac1 = thread->dac2 = 0;
+#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
+	thread->dvc1 = thread->dvc2 = 0;
+#endif
+	thread->dbcr0 = 0;
+#ifdef CONFIG_BOOKE
+	/*
+	 * Force User/Supervisor bits to b11 (user-only MSR[PR]=1)
+	 */
+	thread->dbcr1 = DBCR1_IAC1US | DBCR1_IAC2US |	\
+			DBCR1_IAC3US | DBCR1_IAC4US;
+	/*
+	 * Force Data Address Compare User/Supervisor bits to be User-only
+	 * (0b11 MSR[PR]=1) and set all other bits in DBCR2 register to be 0.
+	 */
+	thread->dbcr2 = DBCR2_DAC1US | DBCR2_DAC2US;
+#else
+	thread->dbcr1 = 0;
+#endif
+}
+
+static void prime_debug_regs(struct thread_struct *thread)
+{
+	mtspr(SPRN_IAC1, thread->iac1);
+	mtspr(SPRN_IAC2, thread->iac2);
+#if CONFIG_PPC_ADV_DEBUG_IACS > 2
+	mtspr(SPRN_IAC3, thread->iac3);
+	mtspr(SPRN_IAC4, thread->iac4);
+#endif
+	mtspr(SPRN_DAC1, thread->dac1);
+	mtspr(SPRN_DAC2, thread->dac2);
+#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
+	mtspr(SPRN_DVC1, thread->dvc1);
+	mtspr(SPRN_DVC2, thread->dvc2);
+#endif
+	mtspr(SPRN_DBCR0, thread->dbcr0);
+	mtspr(SPRN_DBCR1, thread->dbcr1);
+#ifdef CONFIG_BOOKE
+	mtspr(SPRN_DBCR2, thread->dbcr2);
+#endif
+}
+/*
+ * Unless neither the old or new thread are making use of the
+ * debug registers, set the debug registers from the values
+ * stored in the new thread.
+ */
+static void switch_booke_debug_regs(struct thread_struct *new_thread)
+{
+	if ((current->thread.dbcr0 & DBCR0_IDM)
+		|| (new_thread->dbcr0 & DBCR0_IDM))
+			prime_debug_regs(new_thread);
+}
+#else	/* !CONFIG_PPC_ADV_DEBUG_REGS */
+static void set_debug_reg_defaults(struct thread_struct *thread)
+{
+	if (thread->dabr) {
+		thread->dabr = 0;
+		set_dabr(0);
+	}
+}
+#endif	/* CONFIG_PPC_ADV_DEBUG_REGS */
+
 int set_dabr(unsigned long dabr)
 {
 	__get_cpu_var(current_dabr) = dabr;
@@ -372,9 +457,7 @@ struct task_struct *__switch_to(struct task_struct *prev,
 #endif /* CONFIG_SMP */
 
 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
-	/* If new thread DAC (HW breakpoint) is the same then leave it */
-	if (new->thread.dabr)
-		set_dabr(new->thread.dabr);
+	switch_booke_debug_regs(&new->thread);
 #else
 	if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr))
 		set_dabr(new->thread.dabr);
@@ -556,14 +639,7 @@ void flush_thread(void)
 {
 	discard_lazy_cpu_state();
 
-	if (current->thread.dabr) {
-		current->thread.dabr = 0;
-		set_dabr(0);
-
-#ifdef CONFIG_PPC_ADV_DEBUG_REGS
-		current->thread.dbcr0 &= ~(DBSR_DAC1R | DBSR_DAC1W);
-#endif
-	}
+	set_debug_reg_defaults(&current->thread);
 }
 
 void
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 8847bd6..d9b0586 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -738,11 +738,22 @@ void user_disable_single_step(struct task_struct *task)
 
 	if (regs != NULL) {
 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
-		/* If DAC don't clear DBCRO_IDM or MSR_DE */
-		if (task->thread.dabr)
-			task->thread.dbcr0 &= ~(DBCR0_IC | DBCR0_BT);
-		else {
-			task->thread.dbcr0 &= ~(DBCR0_IC | DBCR0_BT | DBCR0_IDM);
+		/*
+		 * 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.dbcr0 &= ~DBCR0_IC;
+		/*
+		 * Test to see if any of the DBCR_ACTIVE_EVENTS bits are set.
+		 */
+		if (!DBCR_ACTIVE_EVENTS(task->thread.dbcr0,
+					task->thread.dbcr1)) {
+			/*
+			 * All debug events were off.....
+			 */
+			task->thread.dbcr0 &= ~DBCR0_IDM;
 			regs->msr &= ~MSR_DE;
 		}
 #else
@@ -767,7 +778,6 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr,
 		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
@@ -786,20 +796,22 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr,
 
 	/* Move contents to the DABR register */
 	task->thread.dabr = data;
-
 #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.dabr = data & ~0x3UL;
-
-	if (task->thread.dabr == 0) {
-		task->thread.dbcr0 &= ~(DBSR_DAC1R | DBSR_DAC1W | DBCR0_IDM);
-		task->thread.regs->msr &= ~MSR_DE;
+	task->thread.dac1 = data & ~0x3UL;
+
+	if (task->thread.dac1 == 0) {
+		dbcr_dac(task) &= ~(DBCR_DAC1R | DBCR_DAC1W);
+		if (!DBCR_ACTIVE_EVENTS(task->thread.dbcr0,
+					task->thread.dbcr1)) {
+			task->thread.regs->msr &= ~MSR_DE;
+			task->thread.dbcr0 &= ~DBCR0_IDM;
+		}
 		return 0;
 	}
 
@@ -810,15 +822,15 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr,
 
 	/* Set the Internal Debugging flag (IDM bit 1) for the DBCR0
 	   register */
-	task->thread.dbcr0 = DBCR0_IDM;
+	task->thread.dbcr0 |= DBCR0_IDM;
 
 	/* Check for write and read flags and set DBCR0
 	   accordingly */
+	dbcr_dac(task) &= ~(DBCR_DAC1R|DBCR_DAC1W);
 	if (data & 0x1UL)
-		task->thread.dbcr0 |= DBSR_DAC1R;
+		dbcr_dac(task) |= DBCR_DAC1R;
 	if (data & 0x2UL)
-		task->thread.dbcr0 |= DBSR_DAC1W;
-
+		dbcr_dac(task) |= DBCR_DAC1W;
 	task->thread.regs->msr |= MSR_DE;
 #endif /* CONFIG_PPC_ADV_DEBUG_REGS */
 	return 0;
@@ -835,11 +847,344 @@ void ptrace_disable(struct task_struct *child)
 	user_disable_single_step(child);
 }
 
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+static long set_intruction_bp(struct task_struct *child,
+			      struct ppc_hw_breakpoint *bp_info)
+{
+	int slot;
+	int slot1_in_use = ((child->thread.dbcr0 & DBCR0_IAC1) != 0);
+	int slot2_in_use = ((child->thread.dbcr0 & DBCR0_IAC2) != 0);
+	int slot3_in_use = ((child->thread.dbcr0 & DBCR0_IAC3) != 0);
+	int slot4_in_use = ((child->thread.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.iac1 = bp_info->addr;
+			child->thread.iac2 = bp_info->addr2;
+			child->thread.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.iac3 = bp_info->addr;
+			child->thread.iac4 = bp_info->addr2;
+			child->thread.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.iac1 = bp_info->addr;
+				child->thread.dbcr0 |= DBCR0_IAC1;
+				goto out;
+			}
+		}
+		if (!slot2_in_use) {
+			slot = 2;
+			child->thread.iac2 = bp_info->addr;
+			child->thread.dbcr0 |= DBCR0_IAC2;
+#if CONFIG_PPC_ADV_DEBUG_IACS > 2
+		} else if (!slot3_in_use) {
+			slot = 3;
+			child->thread.iac3 = bp_info->addr;
+			child->thread.dbcr0 |= DBCR0_IAC3;
+		} else if (!slot4_in_use) {
+			slot = 4;
+			child->thread.iac4 = bp_info->addr;
+			child->thread.dbcr0 |= DBCR0_IAC4;
+#endif
+		} else
+			return -ENOSPC;
+	}
+out:
+	child->thread.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.iac1 == 0)
+			return -ENOENT;
+
+		if (dbcr_iac_range(child) & DBCR_IAC12MODE) {
+			/* address range - clear slots 1 & 2 */
+			child->thread.iac2 = 0;
+			dbcr_iac_range(child) &= ~DBCR_IAC12MODE;
+		}
+		child->thread.iac1 = 0;
+		child->thread.dbcr0 &= ~DBCR0_IAC1;
+		break;
+	case 2:
+		if (child->thread.iac2 == 0)
+			return -ENOENT;
+
+		if (dbcr_iac_range(child) & DBCR_IAC12MODE)
+			/* used in a range */
+			return -EINVAL;
+		child->thread.iac2 = 0;
+		child->thread.dbcr0 &= ~DBCR0_IAC2;
+		break;
+#if CONFIG_PPC_ADV_DEBUG_IACS > 2
+	case 3:
+		if (child->thread.iac3 == 0)
+			return -ENOENT;
+
+		if (dbcr_iac_range(child) & DBCR_IAC34MODE) {
+			/* address range - clear slots 3 & 4 */
+			child->thread.iac4 = 0;
+			dbcr_iac_range(child) &= ~DBCR_IAC34MODE;
+		}
+		child->thread.iac3 = 0;
+		child->thread.dbcr0 &= ~DBCR0_IAC3;
+		break;
+	case 4:
+		if (child->thread.iac4 == 0)
+			return -ENOENT;
+
+		if (dbcr_iac_range(child) & DBCR_IAC34MODE)
+			/* Used in a range */
+			return -EINVAL;
+		child->thread.iac4 = 0;
+		child->thread.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.dac1 = (unsigned long)bp_info->addr;
+#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
+		if (byte_enable) {
+			child->thread.dvc1 =
+				(unsigned long)bp_info->condition_value;
+			child->thread.dbcr2 |=
+				((byte_enable << DBCR2_DVC1BE_SHIFT) |
+				 (condition_mode << DBCR2_DVC1M_SHIFT));
+		}
+#endif
+#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
+	} else if (child->thread.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.dac2 = (unsigned long)bp_info->addr;
+#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
+		if (byte_enable) {
+			child->thread.dvc2 =
+				(unsigned long)bp_info->condition_value;
+			child->thread.dbcr2 |=
+				((byte_enable << DBCR2_DVC2BE_SHIFT) |
+				 (condition_mode << DBCR2_DVC2M_SHIFT));
+		}
+#endif
+	} else
+		return -ENOSPC;
+	child->thread.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 (child->thread.dac1 == 0)
+			return -ENOENT;
+
+		child->thread.dac1 = 0;
+		dbcr_dac(child) &= ~(DBCR_DAC1R | DBCR_DAC1W);
+#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
+		if (child->thread.dbcr2 & DBCR2_DAC12MODE) {
+			child->thread.dac2 = 0;
+			child->thread.dbcr2 &= ~DBCR2_DAC12MODE;
+		}
+		child->thread.dbcr2 &= ~(DBCR2_DVC1M | DBCR2_DVC1BE);
+#endif
+#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
+		child->thread.dvc1 = 0;
+#endif
+	} else if (slot == 2) {
+		if (child->thread.dac1 == 0)
+			return -ENOENT;
+
+#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
+		if (child->thread.dbcr2 & DBCR2_DAC12MODE)
+			/* Part of a range */
+			return -EINVAL;
+		child->thread.dbcr2 &= ~(DBCR2_DVC2M | DBCR2_DVC2BE);
+#endif
+#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
+		child->thread.dvc2 = 0;
+#endif
+		child->thread.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.dbcr0 &
+	    (DBCR0_DAC1R | DBCR0_DAC1W | DBCR0_DAC2R | DBCR0_DAC2W))
+		return -ENOSPC;
+
+	if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
+		child->thread.dbcr0 |= (DBCR0_DAC1R | DBCR0_IDM);
+	if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
+		child->thread.dbcr0 |= (DBCR0_DAC1W | DBCR0_IDM);
+	child->thread.dac1 = bp_info->addr;
+	child->thread.dac2 = bp_info->addr2;
+	if (mode == PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE)
+		child->thread.dbcr2  |= DBCR2_DAC12M;
+	else if (mode == PPC_BREAKPOINT_MODE_RANGE_EXCLUSIVE)
+		child->thread.dbcr2  |= DBCR2_DAC12MX;
+	else	/* PPC_BREAKPOINT_MODE_MASK */
+		child->thread.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)
 {
+	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_intruction_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 currently support one data breakpoint
+	 * 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) ||
@@ -855,30 +1200,39 @@ static long ppc_set_hwdebug(struct task_struct *child,
 		return -EIO;
 
 	child->thread.dabr = (unsigned long)bp_info->addr;
-#ifdef CONFIG_PPC_ADV_DEBUG_REGS
-	child->thread.dbcr0 = DBCR0_IDM;
-	if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
-		child->thread.dbcr0 |= DBSR_DAC1R;
-	if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
-		child->thread.dbcr0 |= DBSR_DAC1W;
-	child->thread.regs->msr |= MSR_DE;
-#endif
+
 	return 1;
+#endif /* !CONFIG_PPC_ADV_DEBUG_DVCS */
 }
 
 static long ppc_del_hwdebug(struct task_struct *child, long addr, long data)
 {
+#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.dbcr0,
+					child->thread.dbcr1)) {
+			child->thread.dbcr0 &= ~DBCR0_IDM;
+			child->thread.regs->msr &= ~MSR_DE;
+		}
+	}
+	return rc;
+#else
 	if (data != 1)
 		return -EINVAL;
 	if (child->thread.dabr == 0)
 		return -ENOENT;
 
 	child->thread.dabr = 0;
-#ifdef CONFIG_PPC_ADV_DEBUG_REGS
-	child->thread.dbcr0 &= ~(DBSR_DAC1R | DBSR_DAC1W | DBCR0_IDM);
-	child->thread.regs->msr &= ~MSR_DE;
-#endif
+
 	return 0;
+#endif
 }
 
 /*
@@ -978,6 +1332,20 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 		struct ppc_debug_info dbginfo;
 
 		dbginfo.version = 1;
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+		dbginfo.num_instruction_bps = CONFIG_PPC_ADV_DEBUG_IACS;
+		dbginfo.num_data_bps = CONFIG_PPC_ADV_DEBUG_DACS;
+		dbginfo.num_condition_regs = CONFIG_PPC_ADV_DEBUG_DVCS;
+		dbginfo.data_bp_alignment = 4;
+		dbginfo.sizeof_condition = 4;
+		dbginfo.features = PPC_DEBUG_FEATURE_INSN_BP_RANGE |
+				   PPC_DEBUG_FEATURE_INSN_BP_MASK;
+#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
+		dbginfo.features |=
+				   PPC_DEBUG_FEATURE_DATA_BP_RANGE |
+				   PPC_DEBUG_FEATURE_DATA_BP_MASK;
+#endif
+#else /* !CONFIG_PPC_ADV_DEBUG_REGS */
 		dbginfo.num_instruction_bps = 0;
 		dbginfo.num_data_bps = 1;
 		dbginfo.num_condition_regs = 0;
@@ -988,6 +1356,7 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 #endif
 		dbginfo.sizeof_condition = 0;
 		dbginfo.features = 0;
+#endif /* CONFIG_PPC_ADV_DEBUG_REGS */
 
 		if (!access_ok(VERIFY_WRITE, data,
 			       sizeof(struct ppc_debug_info)))
@@ -1023,8 +1392,13 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 		/* We only support one DABR and no IABRS at the moment */
 		if (addr > 0)
 			break;
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+		ret = put_user(child->thread.dac1,
+			       (unsigned long __user *)data);
+#else
 		ret = put_user(child->thread.dabr,
 			       (unsigned long __user *)data);
+#endif
 		break;
 	}
 
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index ad7044b..a0afb55 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -140,17 +140,15 @@ static int do_signal_pending(sigset_t *oldset, struct pt_regs *regs)
 		return 0;               /* no signals delivered */
 	}
 
+#ifndef CONFIG_PPC_ADV_DEBUG_REGS
         /*
 	 * Reenable the DABR before delivering the signal to
 	 * user space. The DABR will have been cleared if it
 	 * triggered inside the kernel.
 	 */
-	if (current->thread.dabr) {
+	if (current->thread.dabr)
 		set_dabr(current->thread.dabr);
-#ifdef CONFIG_PPC_ADV_DEBUG_REGS
-		mtspr(SPRN_DBCR0, current->thread.dbcr0);
 #endif
-	}
 
 	if (is32) {
         	if (ka.sa.sa_flags & SA_SIGINFO)
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index e4883ae..2666101 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -1092,8 +1092,12 @@ int sys_debug_setcontext(struct ucontext __user *ctx,
 				new_msr |= MSR_DE;
 				new_dbcr0 |= (DBCR0_IDM | DBCR0_IC);
 			} else {
-				new_msr &= ~MSR_DE;
-				new_dbcr0 &= ~(DBCR0_IDM | DBCR0_IC);
+				new_dbcr0 &= ~DBCR0_IC;
+				if (!DBCR_ACTIVE_EVENTS(new_dbcr0,
+						current->thread.dbcr1)) {
+					new_msr &= ~MSR_DE;
+					new_dbcr0 &= ~DBCR0_IDM;
+				}
 			}
 #else
 			if (op.dbg_value)
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 4e293b7..987437e 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1034,9 +1034,68 @@ void SoftwareEmulation(struct pt_regs *regs)
 #endif /* CONFIG_8xx */
 
 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
+static void handle_debug(struct pt_regs *regs, unsigned long debug_status)
+{
+	int changed = 0;
+	/*
+	 * Determine the cause of the debug event, clear the
+	 * event flags and send a trap to the handler. Torez
+	 */
+	if (debug_status & (DBSR_DAC1R | DBSR_DAC1W)) {
+		dbcr_dac(current) &= ~(DBCR_DAC1R | DBCR_DAC1W);
+#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
+		current->thread.dbcr2 &= ~DBCR2_DAC12MODE;
+#endif
+		do_send_trap(regs, mfspr(SPRN_DAC1), debug_status, TRAP_HWBKPT,
+			     5);
+		changed |= 0x01;
+	}  else if (debug_status & (DBSR_DAC2R | DBSR_DAC2W)) {
+		dbcr_dac(current) &= ~(DBCR_DAC2R | DBCR_DAC2W);
+		do_send_trap(regs, mfspr(SPRN_DAC2), debug_status, TRAP_HWBKPT,
+			     6);
+		changed |= 0x01;
+	}  else if (debug_status & DBSR_IAC1) {
+		current->thread.dbcr0 &= ~DBCR0_IAC1;
+		dbcr_iac_range(current) &= ~DBCR_IAC12MODE;
+		do_send_trap(regs, mfspr(SPRN_IAC1), debug_status, TRAP_HWBKPT,
+			     1);
+		changed |= 0x01;
+	}  else if (debug_status & DBSR_IAC2) {
+		current->thread.dbcr0 &= ~DBCR0_IAC2;
+		do_send_trap(regs, mfspr(SPRN_IAC2), debug_status, TRAP_HWBKPT,
+			     2);
+		changed |= 0x01;
+	}  else if (debug_status & DBSR_IAC3) {
+		current->thread.dbcr0 &= ~DBCR0_IAC3;
+		dbcr_iac_range(current) &= ~DBCR_IAC34MODE;
+		do_send_trap(regs, mfspr(SPRN_IAC3), debug_status, TRAP_HWBKPT,
+			     3);
+		changed |= 0x01;
+	}  else if (debug_status & DBSR_IAC4) {
+		current->thread.dbcr0 &= ~DBCR0_IAC4;
+		do_send_trap(regs, mfspr(SPRN_IAC4), debug_status, TRAP_HWBKPT,
+			     4);
+		changed |= 0x01;
+	}
+	/*
+	 * At the point this routine was called, the MSR(DE) was turned off.
+	 * Check all other debug flags and see if that bit needs to be turned
+	 * back on or not.
+	 */
+	if (DBCR_ACTIVE_EVENTS(current->thread.dbcr0, current->thread.dbcr1))
+		regs->msr |= MSR_DE;
+	else
+		/* Make sure the IDM flag is off */
+		current->thread.dbcr0 &= ~DBCR0_IDM;
+
+	if (changed & 0x01)
+		mtspr(SPRN_DBCR0, current->thread.dbcr0);
+}
 
 void __kprobes DebugException(struct pt_regs *regs, unsigned long debug_status)
 {
+	current->thread.dbsr = debug_status;
+
 	/* Hack alert: On BookE, Branch Taken stops on the branch itself, while
 	 * on server, it stops on the target of the branch. In order to simulate
 	 * the server behaviour, we thus restart right away with a single step
@@ -1080,27 +1139,21 @@ void __kprobes DebugException(struct pt_regs *regs, unsigned long debug_status)
 		if (debugger_sstep(regs))
 			return;
 
-		if (user_mode(regs))
-			current->thread.dbcr0 &= ~(DBCR0_IC);
-
-		_exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
-	} else if (debug_status & (DBSR_DAC1R | DBSR_DAC1W)) {
-		regs->msr &= ~MSR_DE;
-
 		if (user_mode(regs)) {
-			current->thread.dbcr0 &= ~(DBSR_DAC1R | DBSR_DAC1W |
-								DBCR0_IDM);
-		} else {
-			/* Disable DAC interupts */
-			mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~(DBSR_DAC1R |
-						DBSR_DAC1W | DBCR0_IDM));
-
-			/* Clear the DAC event */
-			mtspr(SPRN_DBSR, (DBSR_DAC1R | DBSR_DAC1W));
+			current->thread.dbcr0 &= ~DBCR0_IC;
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+			if (DBCR_ACTIVE_EVENTS(current->thread.dbcr0,
+					       current->thread.dbcr1))
+				regs->msr |= MSR_DE;
+			else
+				/* Make sure the IDM bit is off */
+				current->thread.dbcr0 &= ~DBCR0_IDM;
+#endif
 		}
-		/* Setup and send the trap to the handler */
-		do_dabr(regs, mfspr(SPRN_DAC1), debug_status);
-	}
+
+		_exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
+	} else
+		handle_debug(regs, debug_status);
 }
 #endif /* CONFIG_PPC_ADV_DEBUG_REGS */