public inbox for linuxppc-dev@ozlabs.org 
 help / color / mirror / Atom feed
From: Nicholas Piggin <npiggin@gmail•com>
To: Christophe Leroy <christophe.leroy@csgroup•eu>,
	linuxppc-dev@lists•ozlabs.org
Subject: Re: [PATCH 03/18] powerpc: bad_page_fault, do_break get registers from regs
Date: Wed, 11 Nov 2020 16:39:33 +1000	[thread overview]
Message-ID: <1605076126.b04m8ile46.astroid@bobo.none> (raw)
In-Reply-To: <1605069958.zq8gnsvl6e.astroid@bobo.none>

Excerpts from Nicholas Piggin's message of November 11, 2020 2:46 pm:
> Excerpts from Christophe Leroy's message of November 10, 2020 9:19 pm:
>> 
>> 
>> Le 10/11/2020 à 09:34, Nicholas Piggin a écrit :
>>> Excerpts from Christophe Leroy's message of November 6, 2020 6:14 pm:
>>>>
>>>>
>>>> Le 05/11/2020 à 15:34, Nicholas Piggin a écrit :
>>>>> This also moves the 32s DABR match to C.
>>>>
>>>> Is there a real benefit doing this ?
>>> 
>>> Oh I missed doing it, but yes I think bad_page_fault and do_break should
>>> probably be implemented with the DEFINE_INTERRUT_HANDLER wrappers.
>>> 
>> 
>> Yes, anyway, do we need to do that change ? Can't the dispatch between do_break() and page fault 
>> handling remain in handle_page_fault() ? What's the benefit of going into do_page_fault() and coming 
>> back ?
> 
> You might be right, I'll take another look at it.

For 32-bit, we need to come back to save NV GPRs. Certainly the 64s code 
stays in do_page_fault because it always saves them.

Now I don't think that's the nicest thing to go in and out of the 
interrupt wrappers twice in these cases, but for a first pass I think 
it's okay. Either we could add another type of error-case wrapper that
does some adjustment if it becomes necessary, or we find a nice way to
save NVGPRs from C code.

If we could somehow parse unwind data to find where the NVGPRs are saved 
by the compiler and generate a little code stub to load them out, would
be the ultimate :) Maybe one day...

Thanks,
Nick

  reply	other threads:[~2020-11-11  6:42 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-05 14:34 [PATCH 00/18] powerpc: interrupt wrappers Nicholas Piggin
2020-11-05 14:34 ` [PATCH 01/18] powerpc/64s: move the last of the page fault handling logic to C Nicholas Piggin
2020-11-05 21:54   ` kernel test robot
2020-11-05 14:34 ` [PATCH 02/18] powerpc: remove arguments from fault handler functions Nicholas Piggin
2020-11-06  7:59   ` Christophe Leroy
2020-11-10  8:29     ` Nicholas Piggin
2020-11-10 11:15       ` Christophe Leroy
2020-11-11  4:45         ` Nicholas Piggin
2020-11-05 14:34 ` [PATCH 03/18] powerpc: bad_page_fault, do_break get registers from regs Nicholas Piggin
2020-11-05 20:43   ` kernel test robot
2020-11-06  8:14   ` Christophe Leroy
2020-11-10  8:34     ` Nicholas Piggin
2020-11-10 11:19       ` Christophe Leroy
2020-11-11  4:46         ` Nicholas Piggin
2020-11-11  6:39           ` Nicholas Piggin [this message]
2020-11-05 14:34 ` [PATCH 04/18] powerpc: interrupt handler wrapper functions Nicholas Piggin
2020-11-05 14:34 ` [PATCH 05/18] powerpc: add interrupt wrapper entry / exit stub functions Nicholas Piggin
2020-11-05 14:34 ` [PATCH 06/18] powerpc: add interrupt_cond_local_irq_enable helper Nicholas Piggin
2020-11-05 14:34 ` [PATCH 07/18] powerpc/64: context tracking remove _TIF_NOHZ Nicholas Piggin
2020-11-05 14:34 ` [PATCH 08/18] powerpc/64: context tracking move to interrupt wrappers Nicholas Piggin
2020-11-05 14:34 ` [PATCH 09/18] powerpc/64: add context tracking to asynchronous interrupts Nicholas Piggin
2020-11-05 14:34 ` [PATCH 10/18] powerpc/64s: move context tracking exit to interrupt exit path Nicholas Piggin
2020-11-05 14:34 ` [PATCH 11/18] powerpc/64s: reconcile interrupts in C Nicholas Piggin
2020-11-05 14:34 ` [PATCH 12/18] powerpc/64: move account_stolen_time into its own function Nicholas Piggin
2020-11-05 14:34 ` [PATCH 13/18] powerpc/64: entry cpu time accounting in C Nicholas Piggin
2020-11-05 14:34 ` [PATCH 14/18] powerpc: move NMI entry/exit code into wrapper Nicholas Piggin
2020-11-05 14:34 ` [PATCH 15/18] powerpc/64s: move NMI soft-mask handling to C Nicholas Piggin
2020-11-05 14:34 ` [PATCH 16/18] powerpc/64s: runlatch interrupt handling in C Nicholas Piggin
2020-11-05 14:34 ` [PATCH 17/18] powerpc/64s: power4 nap fixup " Nicholas Piggin
2020-11-05 14:34 ` [PATCH 18/18] powerpc/64s: move power4 idle entirely to C Nicholas Piggin
2020-11-06  7:34   ` kernel test robot
2020-11-07  9:43   ` Christophe Leroy
2020-11-10  8:43     ` Nicholas Piggin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1605076126.b04m8ile46.astroid@bobo.none \
    --to=npiggin@gmail$(echo .)com \
    --cc=christophe.leroy@csgroup$(echo .)eu \
    --cc=linuxppc-dev@lists$(echo .)ozlabs.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox