@@ -691,6 +691,9 @@
 #define mttmr(rn, v)	asm volatile(MTTMR(rn, %0) : \
 				     : "r" ((unsigned long)(v)) \
 				     : "memory")
+
+extern unsigned long global_dbcr0[];
+
 #endif /* !__ASSEMBLY__ */
 
 #endif /* __ASM_POWERPC_REG_BOOKE_H__ */

@@ -342,13 +342,6 @@ transfer_to_syscall:
 ret_from_syscall:
 	addi    r4,r1,STACK_FRAME_OVERHEAD
 	bl	syscall_exit_prepare
-#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
-	/* 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@h
-	bnel-	load_dbcr0
-#endif
 #ifdef CONFIG_PPC_47x
 	lis	r4,icache_44x_need_flush@ha
 	lwz	r5,icache_44x_need_flush@l(r4)

@@ -153,21 +153,6 @@
 	SAVE_4GPRS(3, r11)
 	SAVE_2GPRS(7, r11)
 	addi	r2,r12,-THREAD
-#if defined(CONFIG_40x)
-	/* 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@h
-	beq+	3f
-	/* From user and task is ptraced - load up global dbcr0 */
-	li	r12,-1			/* clear all pending debug events */
-	mtspr	SPRN_DBSR,r12
-	lis	r11,global_dbcr0@ha
-	addi	r11,r11,global_dbcr0@l
-	lwz	r12,0(r11)
-	mtspr	SPRN_DBCR0,r12
-3:
-#endif
 	b	transfer_to_syscall		/* jump to handler */
 .endm
 

@@ -130,25 +130,6 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
 	SAVE_2GPRS(7, r11)
 
 	addi	r2,r10,-THREAD
-	/* 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(r10)
-	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 */
-	mtspr	SPRN_DBSR,r12
-	lis	r11,global_dbcr0@ha
-	addi	r11,r11,global_dbcr0@l
-#ifdef CONFIG_SMP
-	lwz	r10, TASK_CPU(r2)
-	slwi	r10, r10, 2
-	add	r11, r11, r10
-#endif
-	lwz	r12,0(r11)
-	mtspr	SPRN_DBCR0,r12
-
-3:
 	b	transfer_to_syscall	/* jump to handler */
 .endm
 

@@ -76,6 +76,13 @@ notrace long system_call_exception(long r3, long r4, long r5,
 		kuap_check_amr();
 #endif
 
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+	if (IS_ENABLED(CONFIG_PPC32) && unlikely(current->thread.debug.dbcr0 & DBCR0_IDM)) {
+		mtspr(SPRN_DBSR, -1);
+		mtspr(SPRN_DBCR0, global_dbcr0[smp_processor_id()]);
+	}
+#endif
+
 	account_cpu_user_entry();
 
 	account_stolen_time();

@@ -324,6 +331,22 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
 	local_paca->tm_scratch = regs->msr;
 #endif
 
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+	if (unlikely(current->thread.debug.dbcr0 & DBCR0_IDM)) {
+		/*
+		 * Check to see if the dbcr0 register is set up to debug.
+		 * Use the internal debug mode bit to do this.
+		 */
+		mtmsr(mfmsr() & ~MSR_DE);
+		if (IS_ENABLED(CONFIG_PPC32)) {
+			isync();
+			global_dbcr0[smp_processor_id()] = mfspr(SPRN_DBCR0);
+		}
+		mtspr(SPRN_DBCR0, current->thread.debug.dbcr0);
+		mtspr(SPRN_DBSR, -1);
+	}
+#endif
+
 	account_cpu_user_exit();
 
 #ifdef CONFIG_PPC_BOOK3S_64 /* BOOK3E and ppc32 not using this */

@@ -401,13 +424,17 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned
 		goto again;
 	}
 
-#ifdef CONFIG_PPC_BOOK3E
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
 	if (unlikely(current->thread.debug.dbcr0 & DBCR0_IDM)) {
 		/*
 		 * Check to see if the dbcr0 register is set up to debug.
 		 * Use the internal debug mode bit to do this.
 		 */
 		mtmsr(mfmsr() & ~MSR_DE);
+		if (IS_ENABLED(CONFIG_PPC32)) {
+			isync();
+			global_dbcr0[smp_processor_id()] = mfspr(SPRN_DBCR0);
+		}
 		mtspr(SPRN_DBCR0, current->thread.debug.dbcr0);
 		mtspr(SPRN_DBSR, -1);
 	}