powerpc/watchpoint: Provide DAWR number to __set_breakpoint

Introduce new parameter 'nr' to __set_breakpoint() which indicates
which DAWR should be programed. Also convert current_brk variable
to an array.

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Michael Neuling <mikey@neuling.org>
Link: https://lore.kernel.org/r/20200514111741.97993-7-ravi.bangoria@linux.ibm.com

3 files changed, 12 insertions, 12 deletions

diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index 01f07d91df70..f5472402c06d 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -64,7 +64,7 @@ int arch_install_hw_breakpoint(struct perf_event *bp)
 	 * If so, DABR will be populated in single_step_dabr_instruction().
 	 */
 	if (current->thread.last_hit_ubp != bp)
-		__set_breakpoint(info);
+		__set_breakpoint(0, info);
 
 	return 0;
 }
@@ -222,7 +222,7 @@ void thread_change_pc(struct task_struct *tsk, struct pt_regs *regs)
 
 	info = counter_arch_bp(tsk->thread.last_hit_ubp);
 	regs->msr &= ~MSR_SE;
-	__set_breakpoint(info);
+	__set_breakpoint(0, info);
 	tsk->thread.last_hit_ubp = NULL;
 }
 
@@ -347,7 +347,7 @@ int hw_breakpoint_handler(struct die_args *args)
 	if (!(info->type & HW_BRK_TYPE_EXTRANEOUS_IRQ))
 		perf_bp_event(bp, regs);
 
-	__set_breakpoint(info);
+	__set_breakpoint(0, info);
 out:
 	rcu_read_unlock();
 	return rc;
@@ -380,7 +380,7 @@ static int single_step_dabr_instruction(struct die_args *args)
 	if (!(info->type & HW_BRK_TYPE_EXTRANEOUS_IRQ))
 		perf_bp_event(bp, regs);
 
-	__set_breakpoint(info);
+	__set_breakpoint(0, info);
 	current->thread.last_hit_ubp = NULL;
 
 	/*
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index dc161b0adc82..f303aea61794 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -637,7 +637,7 @@ void do_break (struct pt_regs *regs, unsigned long address,
 }
 #endif	/* CONFIG_PPC_ADV_DEBUG_REGS */
 
-static DEFINE_PER_CPU(struct arch_hw_breakpoint, current_brk);
+static DEFINE_PER_CPU(struct arch_hw_breakpoint, current_brk[HBP_NUM_MAX]);
 
 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
 /*
@@ -714,7 +714,7 @@ EXPORT_SYMBOL_GPL(switch_booke_debug_regs);
 static void set_breakpoint(struct arch_hw_breakpoint *brk)
 {
 	preempt_disable();
-	__set_breakpoint(brk);
+	__set_breakpoint(0, brk);
 	preempt_enable();
 }
 
@@ -800,13 +800,13 @@ static inline int set_breakpoint_8xx(struct arch_hw_breakpoint *brk)
 	return 0;
 }
 
-void __set_breakpoint(struct arch_hw_breakpoint *brk)
+void __set_breakpoint(int nr, struct arch_hw_breakpoint *brk)
 {
-	memcpy(this_cpu_ptr(&current_brk), brk, sizeof(*brk));
+	memcpy(this_cpu_ptr(&current_brk[nr]), brk, sizeof(*brk));
 
 	if (dawr_enabled())
 		// Power8 or later
-		set_dawr(0, brk);
+		set_dawr(nr, brk);
 	else if (IS_ENABLED(CONFIG_PPC_8xx))
 		set_breakpoint_8xx(brk);
 	else if (!cpu_has_feature(CPU_FTR_ARCH_207S))
@@ -1174,8 +1174,8 @@ struct task_struct *__switch_to(struct task_struct *prev,
  * schedule DABR
  */
 #ifndef CONFIG_HAVE_HW_BREAKPOINT
-	if (unlikely(!hw_brk_match(this_cpu_ptr(&current_brk), &new->thread.hw_brk)))
-		__set_breakpoint(&new->thread.hw_brk);
+	if (unlikely(!hw_brk_match(this_cpu_ptr(&current_brk[0]), &new->thread.hw_brk)))
+		__set_breakpoint(0, &new->thread.hw_brk);
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 #endif
 
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index a46c3fdb6853..8e29138a344a 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -272,7 +272,7 @@ static void do_signal(struct task_struct *tsk)
 	 * triggered inside the kernel.
 	 */
 	if (tsk->thread.hw_brk.address && tsk->thread.hw_brk.type)
-		__set_breakpoint(&tsk->thread.hw_brk);
+		__set_breakpoint(0, &tsk->thread.hw_brk);
 #endif
 	/* Re-enable the breakpoints for the signal stack */
 	thread_change_pc(tsk, tsk->thread.regs);