All of lore.kernel.org
 help / color / mirror / Atom feed
From: Thomas Petazzoni via buildroot <buildroot@buildroot.org>
To: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: "Bernd Kuhls" <bernd.kuhls@t-online.de>,
	"Michael Ellerman" <mpe@ellerman.id.au>,
	"Joel Stanley" <joel@jms.id.au>,
	buildroot@buildroot.org, "Romain Naour" <romain.naour@gmail.com>,
	"Cédric Le Goater" <clg@kaod.org>
Subject: Re: [Buildroot] [PATCH 1/9] arch/powerpc: Hide SPE ABI behind CPU type
Date: Wed, 3 Aug 2022 23:22:21 +0200	[thread overview]
Message-ID: <20220803232221.691911fe@windsurf> (raw)
In-Reply-To: <20220729211755.GE1554632@scaer>

Hello,

On Fri, 29 Jul 2022 23:17:55 +0200
"Yann E. MORIN" <yann.morin.1998@free.fr> wrote:

> I don't understand this change. Currently we have:
> 
>  1. If BR2_POWERPC_CPU_HAS_SPE=y:
>     BR2_powerpc_CLASSIC is not selectable
>     BR2_powerpc_SPE is the only choice
> 
>   2. if BR2_POWERPC_CPU_HAS_SPE is not set:
>     BR2_powerpc_CLASSIC is the only choice
>     BR2_powerpc_SPE is not selectable
> 
> This means that the choice was really nt a choice, because the value of
> HAS_SPE implies which option is settable or not.
> 
> With your change, the BR2_powerpc_CLASSIC will never be selectable at
> all, and BR2_powerpc_SPE will be forcibly set when
> BR2_POWERPC_CPU_HAS_SPE=y
> 
> So we should just drop the choice altogether, and use the SPE ABI when
> the CPu has SPE.

I agree with your analysis here. I would like to go one step further:
SPE is only used by two PowerPC cores:

config BR2_powerpc_8540
        bool "8540 / e500v1"
        depends on !BR2_ARCH_IS_64
        select BR2_POWERPC_CPU_HAS_SPE
config BR2_powerpc_8548
        bool "8548 / e500v2"
        depends on !BR2_ARCH_IS_64
        select BR2_POWERPC_CPU_HAS_SPE

and SPE is no longer supported by upstream GCC. For now, we have kept
GCC 8.x around just to support this SPE ABI, but it is clearly not a
future proof solution.

Can we drop support for SPE entirely?

Best regards,

Thomas
-- 
Thomas Petazzoni, co-owner and CEO, Bootlin
Embedded Linux and Kernel engineering and training
https://bootlin.com
_______________________________________________
buildroot mailing list
buildroot@buildroot.org
https://lists.buildroot.org/mailman/listinfo/buildroot

  reply	other threads:[~2022-08-03 21:22 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-07-29  0:08 [Buildroot] [PATCH 0/9] powerpc: Fix ppc64le configurations Joel Stanley
2022-07-29  0:08 ` [Buildroot] [PATCH 1/9] arch/powerpc: Hide SPE ABI behind CPU type Joel Stanley
2022-07-29  6:48   ` Cédric Le Goater
2022-07-29 21:17   ` Yann E. MORIN
2022-08-03 21:22     ` Thomas Petazzoni via buildroot [this message]
2022-08-05  6:05       ` Joel Stanley
2022-08-05 15:46         ` Yann E. MORIN
2022-07-29  0:08 ` [Buildroot] [PATCH 2/9] arch/powerpc: Clarify generic CPUs Joel Stanley
2022-07-29  6:48   ` Cédric Le Goater
2022-07-29 21:25   ` Yann E. MORIN
2022-08-03 21:28   ` Thomas Petazzoni via buildroot
2022-07-29  0:08 ` [Buildroot] [PATCH 3/9] arch/powerpc: Enable powerpc64le only on CPUs that support it Joel Stanley
2022-07-29  6:52   ` Cédric Le Goater
2022-07-29 21:37     ` Yann E. MORIN
2022-07-30 21:18       ` Cédric Le Goater
2022-07-31  6:43         ` Yann E. MORIN
2022-07-29 21:33   ` Yann E. MORIN
2022-08-03 21:32   ` Thomas Petazzoni via buildroot
2022-09-18 10:23   ` Arnout Vandecappelle
2022-09-20 17:09     ` Cédric Le Goater
2022-09-20 20:32       ` Arnout Vandecappelle
2022-09-18 10:24   ` Arnout Vandecappelle
2022-07-29  0:08 ` [Buildroot] [PATCH 4/9] package/glibc: Use powerpc64le instead of power8 Joel Stanley
2022-07-29  6:52   ` Cédric Le Goater
2022-07-29 21:41   ` Yann E. MORIN
2022-09-18 10:42   ` Arnout Vandecappelle
2022-07-29  0:09 ` [Buildroot] [PATCH 5/9] arch/powerpc: Add Power9 CPU type Joel Stanley
2022-07-29  6:53   ` Cédric Le Goater
2022-07-29 21:42   ` Yann E. MORIN
2022-09-18 10:43   ` Arnout Vandecappelle
2022-07-29  0:09 ` [Buildroot] [PATCH 6/9] arch/powerpc: Add Power10 " Joel Stanley
2022-07-29  6:53   ` Cédric Le Goater
2022-07-29  0:09 ` [Buildroot] [PATCH 7/9] package/mesa3d: Remove force disable of power8 Joel Stanley
2022-07-29  6:54   ` Cédric Le Goater
2022-07-29  0:09 ` [Buildroot] [PATCH 8/9] package/zlib-ng: Revert Power8 special casing Joel Stanley
2022-07-29  6:55   ` Cédric Le Goater
2022-07-29  0:09 ` [Buildroot] [PATCH 9/9] package/openblas: Add Power9 and Power10 targets Joel Stanley
2022-07-29  6:55   ` Cédric Le Goater
2022-08-03 21:07 ` [Buildroot] [PATCH 0/9] powerpc: Fix ppc64le configurations Yann E. MORIN

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=20220803232221.691911fe@windsurf \
    --to=buildroot@buildroot.org \
    --cc=bernd.kuhls@t-online.de \
    --cc=clg@kaod.org \
    --cc=joel@jms.id.au \
    --cc=mpe@ellerman.id.au \
    --cc=romain.naour@gmail.com \
    --cc=thomas.petazzoni@bootlin.com \
    --cc=yann.morin.1998@free.fr \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.