powerpc: clean up the Book-E HW watchpoint support

* CONFIG_BOOKE is selected by CONFIG_44x so we dont need both
* Fixed a few comments
* Go back to only using DBCR0_IDM to determine if we are using
  debug resources.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

arch/powerpc/kernel/entry_32.S

@@ -148,7 +148,7 @@ transfer_to_handler:
 	/* Check to see if the dbcr0 register is set up to debug.  Use the
 	   internal debug mode bit to do this. */
 	lwz	r12,THREAD_DBCR0(r12)
-	andis.	r12,r12,(DBCR0_IDM  | DBSR_DAC1R | DBSR_DAC1W)@h
+	andis.	r12,r12,DBCR0_IDM@h
 	beq+	3f
 	/* From user and task is ptraced - load up global dbcr0 */
 	li	r12,-1			/* clear all pending debug events */
@@ -292,7 +292,7 @@ syscall_exit_cont:
 	/* If the process has its own DBCR0 value, load it up.  The internal
 	   debug mode bit tells us that dbcr0 should be loaded. */
 	lwz	r0,THREAD+THREAD_DBCR0(r2)
-	andis.	r10,r0,(DBCR0_IDM  | DBSR_DAC1R | DBSR_DAC1W)@h
+	andis.	r10,r0,DBCR0_IDM@h
 	bnel-	load_dbcr0
 #endif
 #ifdef CONFIG_44x
@@ -720,7 +720,7 @@ restore_user:
 	/* Check whether this process has its own DBCR0 value.  The internal
 	   debug mode bit tells us that dbcr0 should be loaded. */
 	lwz	r0,THREAD+THREAD_DBCR0(r2)
-	andis.	r10,r0,(DBCR0_IDM  | DBSR_DAC1R | DBSR_DAC1W)@h
+	andis.	r10,r0,DBCR0_IDM@h
 	bnel-	load_dbcr0
 #endif
 

arch/powerpc/kernel/process.c

@@ -254,7 +254,7 @@ void do_dabr(struct pt_regs *regs, unsigned long address,
 		return;
 
 	/* Clear the DAC and struct entries.  One shot trigger */
-#if (defined(CONFIG_44x) || defined(CONFIG_BOOKE))
+#if defined(CONFIG_BOOKE)
 	mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~(DBSR_DAC1R | DBSR_DAC1W
 							| DBCR0_IDM));
 #endif
@@ -286,7 +286,7 @@ int set_dabr(unsigned long dabr)
 	mtspr(SPRN_DABR, dabr);
 #endif
 
-#if defined(CONFIG_44x) || defined(CONFIG_BOOKE)
+#if defined(CONFIG_BOOKE)
 	mtspr(SPRN_DAC1, dabr);
 #endif
 
@@ -373,7 +373,7 @@ struct task_struct *__switch_to(struct task_struct *prev,
 	if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr))
 		set_dabr(new->thread.dabr);
 
-#if defined(CONFIG_44x) || defined(CONFIG_BOOKE)
+#if defined(CONFIG_BOOKE)
 	/* If new thread DAC (HW breakpoint) is the same then leave it */
 	if (new->thread.dabr)
 		set_dabr(new->thread.dabr);
@@ -568,7 +568,7 @@ void flush_thread(void)
 		current->thread.dabr = 0;
 		set_dabr(0);
 
-#if defined(CONFIG_44x) || defined(CONFIG_BOOKE)
+#if defined(CONFIG_BOOKE)
 		current->thread.dbcr0 &= ~(DBSR_DAC1R | DBSR_DAC1W);
 #endif
 	}

arch/powerpc/kernel/ptrace.c

@@ -717,7 +717,7 @@ void user_disable_single_step(struct task_struct *task)
 	struct pt_regs *regs = task->thread.regs;
 
 
-#if defined(CONFIG_44x) || defined(CONFIG_BOOKE)
+#if defined(CONFIG_BOOKE)
 	/* If DAC then do not single step, skip */
 	if (task->thread.dabr)
 		return;
@@ -744,10 +744,11 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr,
 	if (addr > 0)
 		return -EINVAL;
 
+	/* The bottom 3 bits in dabr are flags */
 	if ((data & ~0x7UL) >= TASK_SIZE)
 		return -EIO;
 
-#ifdef CONFIG_PPC64
+#ifndef CONFIG_BOOKE
 
 	/* For processors using DABR (i.e. 970), the bottom 3 bits are flags.
 	 *  It was assumed, on previous implementations, that 3 bits were
@@ -769,7 +770,7 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr,
 	task->thread.dabr = data;
 
 #endif
-#if defined(CONFIG_44x) || defined(CONFIG_BOOKE)
+#if defined(CONFIG_BOOKE)
 
 	/* 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

arch/powerpc/kernel/signal.c

@@ -147,7 +147,7 @@ int do_signal(sigset_t *oldset, struct pt_regs *regs)
 	 */
 	if (current->thread.dabr) {
 		set_dabr(current->thread.dabr);
-#if defined(CONFIG_44x) || defined(CONFIG_BOOKE)
+#if defined(CONFIG_BOOKE)
 		mtspr(SPRN_DBCR0, current->thread.dbcr0);
 #endif
 	}