2018-11-28 11:30:57

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH] powerpc/8xx: hide itlbie and dtlbie symbols

When disassembling InstructionTLBError we get the following messy code:

c000138c: 7d 84 63 78 mr r4,r12
c0001390: 75 25 58 00 andis. r5,r9,22528
c0001394: 75 2a 40 00 andis. r10,r9,16384
c0001398: 41 a2 00 08 beq c00013a0 <itlbie>
c000139c: 7c 00 22 64 tlbie r4,r0

c00013a0 <itlbie>:
c00013a0: 39 40 04 01 li r10,1025
c00013a4: 91 4b 00 b0 stw r10,176(r11)
c00013a8: 39 40 10 32 li r10,4146
c00013ac: 48 00 cc 59 bl c000e004 <transfer_to_handler>

For a cleaner code dump, this patch replaces itlbie and dtlbie
symbols by numeric symbols.

c000138c: 7d 84 63 78 mr r4,r12
c0001390: 75 25 58 00 andis. r5,r9,22528
c0001394: 75 2a 40 00 andis. r10,r9,16384
c0001398: 41 a2 00 08 beq c00013a0 <InstructionTLBError+0xa0>
c000139c: 7c 00 22 64 tlbie r4,r0
c00013a0: 39 40 04 01 li r10,1025
c00013a4: 91 4b 00 b0 stw r10,176(r11)
c00013a8: 39 40 10 32 li r10,4146
c00013ac: 48 00 cc 59 bl c000e004 <transfer_to_handler>
Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/kernel/head_8xx.S | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 3b67b9533c82..8c848acfe249 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -552,11 +552,10 @@ InstructionTLBError:
mr r4,r12
andis. r5,r9,DSISR_SRR1_MATCH_32S@h /* Filter relevant SRR1 bits */
andis. r10,r9,SRR1_ISI_NOPT@h
- beq+ 1f
+ beq+ 1301f
tlbie r4
-itlbie:
/* 0x400 is InstructionAccess exception, needed by bad_page_fault() */
-1: EXC_XFER_LITE(0x400, handle_page_fault)
+1301: EXC_XFER_LITE(0x400, handle_page_fault)

/* This is the data TLB error on the MPC8xx. This could be due to
* many reasons, including a dirty update to a pte. We bail out to
@@ -578,10 +577,9 @@ DARFixed:/* Return from dcbx instruction bug workaround */
stw r5,_DSISR(r11)
mfspr r4,SPRN_DAR
andis. r10,r5,DSISR_NOHPTE@h
- beq+ 1f
+ beq+ 1401f
tlbie r4
-dtlbie:
-1: li r10,RPN_PATTERN
+1401: li r10,RPN_PATTERN
mtspr SPRN_DAR,r10 /* Tag DAR, to be used in DTLB Error */
/* 0x300 is DataAccess exception, needed by bad_page_fault() */
EXC_XFER_LITE(0x300, handle_page_fault)
@@ -604,8 +602,8 @@ DataBreakpoint:
mtspr SPRN_SPRG_SCRATCH1, r11
mfcr r10
mfspr r11, SPRN_SRR0
- cmplwi cr0, r11, (dtlbie - PAGE_OFFSET)@l
- cmplwi cr7, r11, (itlbie - PAGE_OFFSET)@l
+ cmplwi cr0, r11, (1401b - PAGE_OFFSET)@l
+ cmplwi cr7, r11, (1301b - PAGE_OFFSET)@l
beq- cr0, 11f
beq- cr7, 11f
EXCEPTION_PROLOG_1
--
2.13.3



2018-12-12 13:08:32

by Michael Ellerman

[permalink] [raw]
Subject: Re: [PATCH] powerpc/8xx: hide itlbie and dtlbie symbols

Christophe Leroy <[email protected]> writes:

> When disassembling InstructionTLBError we get the following messy code:
>
> c000138c: 7d 84 63 78 mr r4,r12
> c0001390: 75 25 58 00 andis. r5,r9,22528
> c0001394: 75 2a 40 00 andis. r10,r9,16384
> c0001398: 41 a2 00 08 beq c00013a0 <itlbie>
> c000139c: 7c 00 22 64 tlbie r4,r0
>
> c00013a0 <itlbie>:
> c00013a0: 39 40 04 01 li r10,1025
> c00013a4: 91 4b 00 b0 stw r10,176(r11)
> c00013a8: 39 40 10 32 li r10,4146
> c00013ac: 48 00 cc 59 bl c000e004 <transfer_to_handler>
>
> For a cleaner code dump, this patch replaces itlbie and dtlbie
> symbols by numeric symbols.
>
> c000138c: 7d 84 63 78 mr r4,r12
> c0001390: 75 25 58 00 andis. r5,r9,22528
> c0001394: 75 2a 40 00 andis. r10,r9,16384
> c0001398: 41 a2 00 08 beq c00013a0 <InstructionTLBError+0xa0>
> c000139c: 7c 00 22 64 tlbie r4,r0
> c00013a0: 39 40 04 01 li r10,1025
> c00013a4: 91 4b 00 b0 stw r10,176(r11)
> c00013a8: 39 40 10 32 li r10,4146
> c00013ac: 48 00 cc 59 bl c000e004 <transfer_to_handler>
> Signed-off-by: Christophe Leroy <[email protected]>
> ---
> arch/powerpc/kernel/head_8xx.S | 14 ++++++--------
> 1 file changed, 6 insertions(+), 8 deletions(-)
>
> diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
> index 3b67b9533c82..8c848acfe249 100644
> --- a/arch/powerpc/kernel/head_8xx.S
> +++ b/arch/powerpc/kernel/head_8xx.S
> @@ -552,11 +552,10 @@ InstructionTLBError:
> mr r4,r12
> andis. r5,r9,DSISR_SRR1_MATCH_32S@h /* Filter relevant SRR1 bits */
> andis. r10,r9,SRR1_ISI_NOPT@h
> - beq+ 1f
> + beq+ 1301f
> tlbie r4
> -itlbie:
> /* 0x400 is InstructionAccess exception, needed by bad_page_fault() */
> -1: EXC_XFER_LITE(0x400, handle_page_fault)
> +1301: EXC_XFER_LITE(0x400, handle_page_fault)

You could use a local symbol, something like:

beq+ 1f
tlbie r4
.Litlbie:
/* 0x400 is InstructionAccess exception, needed by bad_page_fault() */
1: EXC_XFER_LITE(0x400, handle_page_fault)


cheers

2018-12-13 08:11:21

by Christophe Leroy

[permalink] [raw]
Subject: Re: [PATCH] powerpc/8xx: hide itlbie and dtlbie symbols



Le 12/12/2018 à 14:05, Michael Ellerman a écrit :
> Christophe Leroy <[email protected]> writes:
>
>> When disassembling InstructionTLBError we get the following messy code:
>>
>> c000138c: 7d 84 63 78 mr r4,r12
>> c0001390: 75 25 58 00 andis. r5,r9,22528
>> c0001394: 75 2a 40 00 andis. r10,r9,16384
>> c0001398: 41 a2 00 08 beq c00013a0 <itlbie>
>> c000139c: 7c 00 22 64 tlbie r4,r0
>>
>> c00013a0 <itlbie>:
>> c00013a0: 39 40 04 01 li r10,1025
>> c00013a4: 91 4b 00 b0 stw r10,176(r11)
>> c00013a8: 39 40 10 32 li r10,4146
>> c00013ac: 48 00 cc 59 bl c000e004 <transfer_to_handler>
>>
>> For a cleaner code dump, this patch replaces itlbie and dtlbie
>> symbols by numeric symbols.
>>
>> c000138c: 7d 84 63 78 mr r4,r12
>> c0001390: 75 25 58 00 andis. r5,r9,22528
>> c0001394: 75 2a 40 00 andis. r10,r9,16384
>> c0001398: 41 a2 00 08 beq c00013a0 <InstructionTLBError+0xa0>
>> c000139c: 7c 00 22 64 tlbie r4,r0
>> c00013a0: 39 40 04 01 li r10,1025
>> c00013a4: 91 4b 00 b0 stw r10,176(r11)
>> c00013a8: 39 40 10 32 li r10,4146
>> c00013ac: 48 00 cc 59 bl c000e004 <transfer_to_handler>
>> Signed-off-by: Christophe Leroy <[email protected]>
>> ---
>> arch/powerpc/kernel/head_8xx.S | 14 ++++++--------
>> 1 file changed, 6 insertions(+), 8 deletions(-)
>>
>> diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
>> index 3b67b9533c82..8c848acfe249 100644
>> --- a/arch/powerpc/kernel/head_8xx.S
>> +++ b/arch/powerpc/kernel/head_8xx.S
>> @@ -552,11 +552,10 @@ InstructionTLBError:
>> mr r4,r12
>> andis. r5,r9,DSISR_SRR1_MATCH_32S@h /* Filter relevant SRR1 bits */
>> andis. r10,r9,SRR1_ISI_NOPT@h
>> - beq+ 1f
>> + beq+ 1301f
>> tlbie r4
>> -itlbie:
>> /* 0x400 is InstructionAccess exception, needed by bad_page_fault() */
>> -1: EXC_XFER_LITE(0x400, handle_page_fault)
>> +1301: EXC_XFER_LITE(0x400, handle_page_fault)
>
> You could use a local symbol, something like:

Thanks for the tip, I sent v2

Christophe

>
> beq+ 1f
> tlbie r4
> .Litlbie:
> /* 0x400 is InstructionAccess exception, needed by bad_page_fault() */
> 1: EXC_XFER_LITE(0x400, handle_page_fault)
>
>
> cheers
>