Patchwork [1/3] powerpc/book3e: load critical/machine/debug exception stack

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Submitter Tiejun Chen
Date Oct. 25, 2012, 6:43 a.m.
Message ID <1351147410-17452-1-git-send-email-tiejun.chen@windriver.com>
Download mbox | patch
Permalink /patch/194059/
State Superseded
Headers show

Comments

Tiejun Chen - Oct. 25, 2012, 6:43 a.m.
We always alloc critical/machine/debug check exceptions. This is
different from the normal exception. So we should load these exception
stack properly like we did for booke.

Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com>
---
 arch/powerpc/kernel/exceptions-64e.S |   27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)
Tabi Timur-B04825 - Dec. 18, 2012, 10:10 p.m.
On Thu, Oct 25, 2012 at 1:43 AM, Tiejun Chen <tiejun.chen@windriver.com> wrote:
> We always alloc critical/machine/debug check exceptions. This is
> different from the normal exception. So we should load these exception
> stack properly like we did for booke.

Tiejun,

I'm a little confused by these patches, because the actual critical
exception handlers are still commented out:

/* Critical Input Interrupt */
	START_EXCEPTION(critical_input);
	CRIT_EXCEPTION_PROLOG(0x100, BOOKE_INTERRUPT_CRITICAL,
			      PROLOG_ADDITION_NONE)
//	EXCEPTION_COMMON(0x100, PACA_EXCRIT, INTS_DISABLE)
//	bl	special_reg_save_crit
//	CHECK_NAPPING();
//	addi	r3,r1,STACK_FRAME_OVERHEAD
//	bl	.critical_exception
//	b	ret_from_crit_except
	b	.

Are you working on fixing this?  I'm trying to fix it, too, but I
think you're way ahead of me.
Tiejun Chen - Dec. 20, 2012, 9:14 a.m.
On 12/19/2012 06:10 AM, Tabi Timur-B04825 wrote:
> On Thu, Oct 25, 2012 at 1:43 AM, Tiejun Chen <tiejun.chen@windriver.com> wrote:
>> We always alloc critical/machine/debug check exceptions. This is
>> different from the normal exception. So we should load these exception
>> stack properly like we did for booke.
>
> Tiejun,
>
> I'm a little confused by these patches, because the actual critical
> exception handlers are still commented out:
>
> /* Critical Input Interrupt */
> 	START_EXCEPTION(critical_input);
> 	CRIT_EXCEPTION_PROLOG(0x100, BOOKE_INTERRUPT_CRITICAL,
> 			      PROLOG_ADDITION_NONE)
> //	EXCEPTION_COMMON(0x100, PACA_EXCRIT, INTS_DISABLE)
> //	bl	special_reg_save_crit
> //	CHECK_NAPPING();
> //	addi	r3,r1,STACK_FRAME_OVERHEAD
> //	bl	.critical_exception
> //	b	ret_from_crit_except
> 	b	.
>
> Are you working on fixing this?  I'm trying to fix it, too, but I

No, I have no approach to Crit/MC and currently I'm focus only on Debug so 
please do this as you expect :)

BTW, I send next version just now since there are something needed to 
correct/improve.

Tiejun

Patch

diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
index 4684e33..43b654a 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -36,6 +36,30 @@ 
  */
 #define	SPECIAL_EXC_FRAME_SIZE	INT_FRAME_SIZE
 
+/* only on book3e */
+#define DBG_STACK_BASE		dbgirq_ctx
+#define MC_STACK_BASE		mcheckirq_ctx
+#define CRIT_STACK_BASE		critirq_ctx
+
+#ifdef CONFIG_SMP
+#define BOOK3E_LOAD_EXC_LEVEL_STACK(level)		\
+	std	r14,PACA_EX##level+EX_R14(r13);		\
+	mfspr	r14,SPRN_PIR;				\
+	slwi	r14,r14,3;				\
+	LOAD_REG_ADDR(r10, level##_STACK_BASE);		\
+	add	r10,r10,r14;				\
+	ld	r10,0(r10);				\
+	addi	r10,r10,THREAD_SIZE;			\
+	std	r10,PACA_DBG_STACK(r13);		\
+	ld	r14,PACA_EX##level+EX_R14(r13);
+#else
+#define BOOK3E_LOAD_EXC_LEVEL_STACK(level)		\
+	LOAD_REG_ADDR(r10, level##_STACK_BASE);		\
+	ld	r10,0(r10);				\
+	addi	r10,r10,THREAD_SIZE;			\
+	std	r10,PACA_DBG_STACK(r13);
+#endif
+
 /* Exception prolog code for all exceptions */
 #define EXCEPTION_PROLOG(n, intnum, type, addition)	    		    \
 	mtspr	SPRN_SPRG_##type##_SCRATCH,r13;	/* get spare registers */   \
@@ -68,18 +92,21 @@ 
 #define SPRN_GDBELL_SRR1	SPRN_GSRR1
 
 #define CRIT_SET_KSTACK						            \
+	BOOK3E_LOAD_EXC_LEVEL_STACK(CRIT);					\
 	ld	r1,PACA_CRIT_STACK(r13);				    \
 	subi	r1,r1,SPECIAL_EXC_FRAME_SIZE;
 #define SPRN_CRIT_SRR0	SPRN_CSRR0
 #define SPRN_CRIT_SRR1	SPRN_CSRR1
 
 #define DBG_SET_KSTACK						            \
+	BOOK3E_LOAD_EXC_LEVEL_STACK(DBG);					\
 	ld	r1,PACA_DBG_STACK(r13);					    \
 	subi	r1,r1,SPECIAL_EXC_FRAME_SIZE;
 #define SPRN_DBG_SRR0	SPRN_DSRR0
 #define SPRN_DBG_SRR1	SPRN_DSRR1
 
 #define MC_SET_KSTACK						            \
+	BOOK3E_LOAD_EXC_LEVEL_STACK(MC);					\
 	ld	r1,PACA_MC_STACK(r13);					    \
 	subi	r1,r1,SPECIAL_EXC_FRAME_SIZE;
 #define SPRN_MC_SRR0	SPRN_MCSRR0