Commit d524dda7 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/32: Handle bookE debugging in C in syscall entry/exit 



The handling of SPRN_DBCR0 and other registers can easily
be done in C instead of ASM.

For that, create booke_load_dbcr0() and booke_restore_dbcr0().

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1a7515f9258b27a9177de88491a8bb79b255ceb7.1612898425.git.christophe.leroy@csgroup.eu
parent b966f227

arch/powerpc/include/asm/interrupt.h

+12 −0
Original line number Diff line number Diff line
@@ -15,6 +15,18 @@ struct interrupt_state { 
#endif

};



static inline void booke_restore_dbcr0(void)

{

#ifdef CONFIG_PPC_ADV_DEBUG_REGS

	unsigned long dbcr0 = current->thread.debug.dbcr0;



	if (IS_ENABLED(CONFIG_PPC32) && unlikely(dbcr0 & DBCR0_IDM)) {

		mtspr(SPRN_DBSR, -1);

		mtspr(SPRN_DBCR0, global_dbcr0[smp_processor_id()]);

	}

#endif

}



static inline void interrupt_enter_prepare(struct pt_regs *regs, struct interrupt_state *state)

{

	/*

arch/powerpc/include/asm/reg_booke.h

+3 −0
Original line number Diff line number Diff line
@@ -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__ */

arch/powerpc/kernel/entry_32.S

+0 −7
Original line number Diff line number Diff line
@@ -343,13 +343,6 @@ ret_from_syscall: 
	addi    r4,r1,STACK_FRAME_OVERHEAD

	li	r5,0

	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)

arch/powerpc/kernel/head_32.h

+0 −15
Original line number Diff line number Diff line
@@ -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

arch/powerpc/kernel/head_booke.h

+0 −19
Original line number Diff line number Diff line
@@ -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