1 files changed, 22 insertions, 4 deletions

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 1738c4127b32..1237f13fed51 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -173,7 +173,7 @@ void __msr_check_and_clear(unsigned long bits)
 EXPORT_SYMBOL(__msr_check_and_clear);
 
 #ifdef CONFIG_PPC_FPU
-void __giveup_fpu(struct task_struct *tsk)
+static void __giveup_fpu(struct task_struct *tsk)
 {
 	unsigned long msr;
 
@@ -556,7 +556,7 @@ void restore_math(struct pt_regs *regs)
 	regs->msr = msr;
 }
 
-void save_all(struct task_struct *tsk)
+static void save_all(struct task_struct *tsk)
 {
 	unsigned long usermsr;
 
@@ -718,7 +718,8 @@ static void set_debug_reg_defaults(struct thread_struct *thread)
 {
 	thread->hw_brk.address = 0;
 	thread->hw_brk.type = 0;
-	set_breakpoint(&thread->hw_brk);
+	if (ppc_breakpoint_available())
+		set_breakpoint(&thread->hw_brk);
 }
 #endif /* !CONFIG_HAVE_HW_BREAKPOINT */
 #endif	/* CONFIG_PPC_ADV_DEBUG_REGS */
@@ -815,9 +816,14 @@ void __set_breakpoint(struct arch_hw_breakpoint *brk)
 	memcpy(this_cpu_ptr(&current_brk), brk, sizeof(*brk));
 
 	if (cpu_has_feature(CPU_FTR_DAWR))
+		// Power8 or later
 		set_dawr(brk);
-	else
+	else if (!cpu_has_feature(CPU_FTR_ARCH_207S))
+		// Power7 or earlier
 		set_dabr(brk);
+	else
+		// Shouldn't happen due to higher level checks
+		WARN_ON_ONCE(1);
 }
 
 void set_breakpoint(struct arch_hw_breakpoint *brk)
@@ -827,6 +833,18 @@ void set_breakpoint(struct arch_hw_breakpoint *brk)
 	preempt_enable();
 }
 
+/* Check if we have DAWR or DABR hardware */
+bool ppc_breakpoint_available(void)
+{
+	if (cpu_has_feature(CPU_FTR_DAWR))
+		return true; /* POWER8 DAWR */
+	if (cpu_has_feature(CPU_FTR_ARCH_207S))
+		return false; /* POWER9 with DAWR disabled */
+	/* DABR: Everything but POWER8 and POWER9 */
+	return true;
+}
+EXPORT_SYMBOL_GPL(ppc_breakpoint_available);
+
 #ifdef CONFIG_PPC64
 DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
 #endif