From: Geert Uytterhoeven <geert@linux-m68k.org>
To: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>,
Rich Felker <dalias@libc.org>, Arnd Bergmann <arnd@arndb.de>,
linux-sh@vger.kernel.org
Subject: Re: [PATCH] sh: boot: Remove sh5 cache handling
Date: Mon, 29 Apr 2024 10:29:22 +0200 [thread overview]
Message-ID: <CAMuHMdWrzme7Nr400-fcsYQx9Pir38COKGGMjnQG3fcpTHt_bg@mail.gmail.com> (raw)
In-Reply-To: <09d677ad889a0bc2d7ae4324e0ca3e90d741b23b.camel@physik.fu-berlin.de>
Hi Adrian,
On Mon, Apr 29, 2024 at 10:22 AM John Paul Adrian Glaubitz
<glaubitz@physik.fu-berlin.de> wrote:
> On Mon, 2024-04-29 at 10:06 +0200, Geert Uytterhoeven wrote:
> > On Mon, Apr 29, 2024 at 9:52 AM John Paul Adrian Glaubitz
> > <glaubitz@physik.fu-berlin.de> wrote:
> > >
> > > Don't have the 32-bit SH CPUs any caches? The code itself is unconditionally executed,
> > > it seems.
> >
> > They do. E.g. SH7751 has 8+8 KiB of L1 cache.
> > But e.g. sh7724 has 32+32KiB L1 cache, and 256 KiB of unified L2 cache.
> > SH772[34] have l2_cache_init() to enable the L2 cache, so probably they
> > boot with L2 disabled, and we are fine.
>
> Understood. But what exactly was the job of cache_control() when all it
> does was flushing the cache area? The cache is not enabled or disabled
I assume flushing the cache was needed to push all code written to RAM.
> here, is it?
No, it is not enabled or disabled. Probably that was planned for later,
cfr. the command parameter.
> Also, I was wondering whether this could be related to the boot lockups
> that I am seeing on my SH-7786LCR which stops after printing "Uncompressing
> Linux...".
I doubt it, unless reading from 0x80000000 causes a lock-up...
> I will test later this week whether your patch actually fixes this issue.
... in which case my patch will help ;-)
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
next prev parent reply other threads:[~2024-04-29 8:29 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-24 11:54 [PATCH] sh: boot: Remove sh5 cache handling Geert Uytterhoeven
2024-04-29 7:46 ` John Paul Adrian Glaubitz
2024-04-29 7:49 ` Geert Uytterhoeven
2024-04-29 7:52 ` John Paul Adrian Glaubitz
2024-04-29 8:06 ` Geert Uytterhoeven
2024-04-29 8:22 ` John Paul Adrian Glaubitz
2024-04-29 8:29 ` Geert Uytterhoeven [this message]
2024-05-02 13:50 ` Yoshinori Sato
2024-05-01 9:26 ` John Paul Adrian Glaubitz
2024-05-02 7:25 ` Geert Uytterhoeven
2024-05-02 10:32 ` John Paul Adrian Glaubitz
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