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From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Nicholas Piggin <npiggin@gmail.com>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 28/43] powerpc/64e: Call bad_page_fault() from do_page_fault()
Date: Fri, 12 Mar 2021 09:39:56 +0100	[thread overview]
Message-ID: <6e5e8283-8aad-cf61-565b-03903e5d20b5@csgroup.eu> (raw)
In-Reply-To: <1615339667.i88ve15v8a.astroid@bobo.none>



Le 10/03/2021 à 02:29, Nicholas Piggin a écrit :
> Excerpts from Christophe Leroy's message of March 9, 2021 10:09 pm:
>> book3e/64 is the last one calling __bad_page_fault()
>> from assembly.
>>
>> Save non volatile registers before calling do_page_fault()
>> and modify do_page_fault() to call __bad_page_fault()
>> for all platforms.
>>
>> Then it can be refactored by the call of bad_page_fault()
>> which avoids the duplication of the exception table search.
> 
> This can go in with the 64e change after your series. I think it should
> be ready for the next merge window as well.

Yes, I thought it would pull more optimisation, but at the end it doesn't bring anythink, so I'll 
drop it for now and leave it to you for your series.

> 
> Thanks,
> Nick
> 
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>>   arch/powerpc/kernel/exceptions-64e.S |  8 +-------
>>   arch/powerpc/mm/fault.c              | 17 ++++-------------
>>   2 files changed, 5 insertions(+), 20 deletions(-)
>>
>> diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
>> index e8eb9992a270..b60f89078a3f 100644
>> --- a/arch/powerpc/kernel/exceptions-64e.S
>> +++ b/arch/powerpc/kernel/exceptions-64e.S
>> @@ -1010,15 +1010,9 @@ storage_fault_common:
>>   	addi	r3,r1,STACK_FRAME_OVERHEAD
>>   	ld	r14,PACA_EXGEN+EX_R14(r13)
>>   	ld	r15,PACA_EXGEN+EX_R15(r13)
>> +	bl	save_nvgprs
>>   	bl	do_page_fault
>> -	cmpdi	r3,0
>> -	bne-	1f
>>   	b	ret_from_except_lite
>> -1:	bl	save_nvgprs
>> -	mr	r4,r3
>> -	addi	r3,r1,STACK_FRAME_OVERHEAD
>> -	bl	__bad_page_fault
>> -	b	ret_from_except
>>   
>>   /*
>>    * Alignment exception doesn't fit entirely in the 0x100 bytes so it
>> diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
>> index 2e54bac99a22..7bcff3fca110 100644
>> --- a/arch/powerpc/mm/fault.c
>> +++ b/arch/powerpc/mm/fault.c
>> @@ -541,24 +541,15 @@ NOKPROBE_SYMBOL(___do_page_fault);
>>   
>>   static long __do_page_fault(struct pt_regs *regs)
>>   {
>> -	const struct exception_table_entry *entry;
>>   	long err;
>>   
>>   	err = ___do_page_fault(regs, regs->dar, regs->dsisr);
>>   	if (likely(!err))
>> -		return err;
>> -
>> -	entry = search_exception_tables(regs->nip);
>> -	if (likely(entry)) {
>> -		instruction_pointer_set(regs, extable_fixup(entry));
>>   		return 0;
>> -	} else if (!IS_ENABLED(CONFIG_PPC_BOOK3E_64)) {
>> -		__bad_page_fault(regs, err);
>> -		return 0;
>> -	} else {
>> -		/* 32 and 64e handle the bad page fault in asm */
>> -		return err;
>> -	}
>> +
>> +	bad_page_fault(regs, err);
>> +
>> +	return 0;
>>   }
>>   NOKPROBE_SYMBOL(__do_page_fault);
>>   
>> -- 
>> 2.25.0
>>
>>

  reply	other threads:[~2021-03-12  8:40 UTC|newest]

Thread overview: 60+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-09 12:09 [PATCH v2 00/43] powerpc/32: Switch to interrupt entry/exit in C Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 01/43] powerpc/traps: unrecoverable_exception() is not an interrupt handler Christophe Leroy
2021-03-10  1:16   ` Nicholas Piggin
2021-03-09 12:09 ` [PATCH v2 02/43] powerpc/traps: Declare unrecoverable_exception() as __noreturn Christophe Leroy
2021-03-10  1:22   ` Nicholas Piggin
2021-03-12  8:40     ` Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 03/43] powerpc/40x: Don't use SPRN_SPRG_SCRATCH0/1 in TLB miss handlers Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 04/43] powerpc/40x: Change CRITICAL_EXCEPTION_PROLOG macro to a gas macro Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 05/43] powerpc/40x: Save SRR0/SRR1 and r10/r11 earlier in critical exception Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 06/43] powerpc/40x: Reorder a few instructions in critical exception prolog Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 07/43] powerpc/40x: Prepare for enabling MMU " Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 08/43] powerpc/40x: Prepare normal exception handler for enabling MMU early Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 09/43] powerpc/32: Reconcile interrupts in C Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 10/43] powerpc/32: Entry cpu time accounting " Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 11/43] powerpc/32: Handle bookE debugging in C in exception entry Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 12/43] powerpc/32: Use fast instruction to set MSR RI in exception prolog on 8xx Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 13/43] powerpc/32: Remove ksp_limit Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 14/43] powerpc/32: Always enable data translation in exception prolog Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 15/43] powerpc/32: Tag DAR in EXCEPTION_PROLOG_2 for the 8xx Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 16/43] powerpc/32: Enable instruction translation at the same time as data translation Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 17/43] powerpc/32: Statically initialise first emergency context Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 18/43] powerpc/32: Add vmap_stack_overflow label inside the macro Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 19/43] powerpc/32: Use START_EXCEPTION() as much as possible Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 20/43] powerpc/32: Move exception prolog code into .text once MMU is back on Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 21/43] powerpc/32: Provide a name to exception prolog continuation in virtual mode Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 22/43] powerpc/32: Refactor booke critical registers saving Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 23/43] powerpc/32: Perform normal function call in exception entry Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 24/43] powerpc/32: Always save non volatile registers on " Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 25/43] powerpc/32: Replace ASM exception exit by C exception exit from ppc64 Christophe Leroy
2021-03-11 13:46   ` Michael Ellerman
2021-03-11 19:39     ` Christophe Leroy
2021-03-11 23:26       ` Michael Ellerman
2021-03-12  8:28         ` Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 26/43] powerpc/32: Set regs parameter in r3 in transfer_to_handler Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 27/43] powerpc/32: Call bad_page_fault() from do_page_fault() Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 28/43] powerpc/64e: " Christophe Leroy
2021-03-10  1:29   ` Nicholas Piggin
2021-03-12  8:39     ` Christophe Leroy [this message]
2021-03-09 12:09 ` [PATCH v2 29/43] powerpc/32: Save trap number on stack in exception prolog Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 30/43] powerpc/32: Add a prepare_transfer_to_handler macro for exception prologs Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 31/43] powerpc/32: Only restore non volatile registers when required Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 32/43] powerpc/32: Dismantle EXC_XFER_STD/LITE/TEMPLATE Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 33/43] powerpc/32: Remove the xfer parameter in EXCEPTION() macro Christophe Leroy
2021-03-09 12:10 ` [PATCH v2 34/43] powerpc/32: Refactor saving of volatile registers in exception prologs Christophe Leroy
2021-03-09 12:10 ` [PATCH v2 35/43] powerpc/32: Save remaining registers in exception prolog Christophe Leroy
2021-03-09 12:10 ` [PATCH v2 36/43] powerpc/32: Set current->thread.regs in C interrupt entry Christophe Leroy
2021-03-10  1:33   ` Nicholas Piggin
2021-03-11 10:38     ` Christophe Leroy
2021-03-11 12:38       ` Christophe Leroy
2021-03-12  1:00         ` Nicholas Piggin
2021-03-09 12:10 ` [PATCH v2 37/43] powerpc/32: Return directly from power_save_ppc32_restore() Christophe Leroy
2021-03-09 12:10 ` [PATCH v2 38/43] powerpc/32: Only use prepare_transfer_to_handler function on book3s/32 and e500 Christophe Leroy
2021-03-09 12:10 ` [PATCH v2 39/43] powerpc/32s: Move KUEP locking/unlocking in C Christophe Leroy
2021-03-09 12:10 ` [PATCH v2 40/43] powerpc/64s: Make kuap_check_amr() and kuap_get_and_check_amr() generic Christophe Leroy
2021-03-10  1:37   ` Nicholas Piggin
2021-03-12  8:37     ` Christophe Leroy
2021-03-09 12:10 ` [PATCH v2 41/43] powerpc/32s: Create C version of kuap save/restore/check helpers Christophe Leroy
2021-03-09 12:10 ` [PATCH v2 42/43] powerpc/8xx: " Christophe Leroy
2021-03-09 12:10 ` [PATCH v2 43/43] powerpc/32: Manage KUAP in C Christophe Leroy
2021-03-14 10:01 ` [PATCH v2 00/43] powerpc/32: Switch to interrupt entry/exit " Michael Ellerman

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