From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To: Vineet Gupta <vgupta@kernel.org>,
linux-snps-arc@lists.infradead.org,
Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org
Subject: Re: [PATCH 2/2] ARC: mm: fix new code about cache aliasing
Date: Thu, 28 Mar 2024 09:57:07 -0400 [thread overview]
Message-ID: <2084d534-5e64-4a38-aba5-aeb03c9e71cd@efficios.com> (raw)
In-Reply-To: <20240328053919.992821-3-vgupta@kernel.org>
On 2024-03-28 01:39, Vineet Gupta wrote:
> Manual/partial revert of 8690bbcf3b70 ("Introduce cpu_dcache_is_aliasing() across all architectures")
>
> Current generation of ARCv2/ARCv3 based HSxx cores are only PIPT (to software
> at least).
>
> Legacy ARC700 cpus could be VIPT aliasing (based on cache geometry and
> PAGE_SIZE) however recently that support was ripped out so VIPT aliasing
> cache is not relevant to ARC anymore.
>
> P.S. : This has been discussed a few times on lists [1]
> P.S.2: Please CC the arch maintainers and/or mailing list before adding
> such interfaces.
Because 8690bbcf3b70 was introducing a tree-wide change affecting all
architectures, I CC'd linux-arch@vger.kernel.org. I expected all
architecture maintainers to follow that list, which is relatively
low volume.
I'm sorry that you learn about this after the fact as a result.
My intent was to use the list rather than CC about 50 additional
people/mailing lists.
Of course, if VIPT aliasing is removed from ARC, removing the
config ARCH_HAS_CPU_CACHE_ALIASING and using the generic
cpu_dcache_is_aliasing() is the way to go. Feel free to add
my:
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Thanks,
Mathieu
>
> [1] http://lists.infradead.org/pipermail/linux-snps-arc/2023-February/006899.html
>
> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
> Signed-off-by: Vineet Gupta <vgupta@kernel.org>
> ---
> arch/arc/Kconfig | 1 -
> arch/arc/include/asm/cachetype.h | 9 ---------
> 2 files changed, 10 deletions(-)
> delete mode 100644 arch/arc/include/asm/cachetype.h
>
> diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
> index 99d2845f3feb..4092bec198be 100644
> --- a/arch/arc/Kconfig
> +++ b/arch/arc/Kconfig
> @@ -6,7 +6,6 @@
> config ARC
> def_bool y
> select ARC_TIMERS
> - select ARCH_HAS_CPU_CACHE_ALIASING
> select ARCH_HAS_CACHE_LINE_SIZE
> select ARCH_HAS_DEBUG_VM_PGTABLE
> select ARCH_HAS_DMA_PREP_COHERENT
> diff --git a/arch/arc/include/asm/cachetype.h b/arch/arc/include/asm/cachetype.h
> deleted file mode 100644
> index 05fc7ed59712..000000000000
> --- a/arch/arc/include/asm/cachetype.h
> +++ /dev/null
> @@ -1,9 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0 */
> -#ifndef __ASM_ARC_CACHETYPE_H
> -#define __ASM_ARC_CACHETYPE_H
> -
> -#include <linux/types.h>
> -
> -#define cpu_dcache_is_aliasing() true
> -
> -#endif
--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com
_______________________________________________
linux-snps-arc mailing list
linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc
next prev parent reply other threads:[~2024-03-28 13:57 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-28 5:39 [PATCH 0/2] ARC minor fixes Vineet Gupta
2024-03-28 5:39 ` [PATCH 1/2] ARC: Fix -Wmissing-prototypes warnings Vineet Gupta
2024-03-28 5:39 ` [PATCH 2/2] ARC: mm: fix new code about cache aliasing Vineet Gupta
2024-03-28 13:57 ` Mathieu Desnoyers [this message]
2024-03-28 17:22 ` Vineet Gupta
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=2084d534-5e64-4a38-aba5-aeb03c9e71cd@efficios.com \
--to=mathieu.desnoyers@efficios.com \
--cc=akpm@linux-foundation.org \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-snps-arc@lists.infradead.org \
--cc=vgupta@kernel.org \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).