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Commit 4eaddb4d authored by Kumar Gala's avatar Kumar Gala
Browse files

[POWERPC] Make Book-E debug handling SMP safe 



global_dbcr0 needs to be a per cpu set of save areas instead of a single
global on all processors.

Also, we switch to using DBCR0_IDM to determine if the user space app is
being debugged as its a more consistent way.  In the future we should
support features like hardware breakpoint and watchpoints which will
have DBCR0_IDM set but not necessarily DBCR0_IC (single step).

Signed-off-by: default avatarKumar Gala <galak@kernel.crashing.org>
parent 3dd82a1e

arch/powerpc/kernel/entry_32.S

+21 −9
Original line number Diff line number Diff line
@@ -110,9 +110,9 @@ transfer_to_handler: 
	stw	r11,PT_REGS(r12)

#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)

	/* Check to see if the dbcr0 register is set up to debug.  Use the

	   single-step bit to do this. */

	   internal debug mode bit to do this. */

	lwz	r12,THREAD_DBCR0(r12)

	andis.	r12,r12,DBCR0_IC@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 */
@@ -120,6 +120,12 @@ transfer_to_handler: 
	lis	r11,global_dbcr0@ha

	tophys(r11,r11)

	addi	r11,r11,global_dbcr0@l

#ifdef CONFIG_SMP

	rlwinm	r9,r1,0,0,(31-THREAD_SHIFT)

	lwz	r9,TI_CPU(r9)

	slwi	r9,r9,3

	add	r11,r11,r9

#endif

	lwz	r12,0(r11)

	mtspr	SPRN_DBCR0,r12

	lwz	r12,4(r11)
@@ -238,10 +244,10 @@ ret_from_syscall: 
	stw	r11,_CCR(r1)

syscall_exit_cont:

#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)

	/* If the process has its own DBCR0 value, load it up.  The single

	   step bit tells us that dbcr0 should be loaded. */

	/* 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_IC@h

	andis.	r10,r0,DBCR0_IDM@h

	bnel-	load_dbcr0

#endif

#ifdef CONFIG_44x
@@ -666,10 +672,10 @@ user_exc_return: /* r10 contains MSR_KERNEL here */ 


restore_user:

#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)

	/* Check whether this process has its own DBCR0 value.  The single

	   step bit tells us that dbcr0 should be loaded. */

	/* 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_IC@h

	andis.	r10,r0,DBCR0_IDM@h

	bnel-	load_dbcr0

#endif
@@ -879,6 +885,12 @@ load_dbcr0: 
	mfspr	r10,SPRN_DBCR0

	lis	r11,global_dbcr0@ha

	addi	r11,r11,global_dbcr0@l

#ifdef CONFIG_SMP

	rlwinm	r9,r1,0,0,(31-THREAD_SHIFT)

	lwz	r9,TI_CPU(r9)

	slwi	r9,r9,3

	add	r11,r11,r9

#endif

	stw	r10,0(r11)

	mtspr	SPRN_DBCR0,r0

	lwz	r10,4(r11)
@@ -891,7 +903,7 @@ load_dbcr0: 
	.section .bss

	.align	4

global_dbcr0:

	.space	8

	.space	8*NR_CPUS

	.previous

#endif /* !(CONFIG_4xx || CONFIG_BOOKE) */