All of lore.kernel.org
 help / color / mirror / Atom feed
From: Volodymyr Babchuk <Volodymyr_Babchuk@epam.com>
To: Julien Grall <julien@xen.org>
Cc: "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>,
	Stewart Hildebrand <stewart.hildebrand@amd.com>,
	Stefano Stabellini <sstabellini@kernel.org>,
	Bertrand Marquis <bertrand.marquis@arm.com>
Subject: Re: [PATCH v1 2/3] ARM: GICv3 ITS: do not invalidate memory while sending a command
Date: Tue, 19 Sep 2023 14:36:01 +0000	[thread overview]
Message-ID: <87fs3afcxb.fsf@epam.com> (raw)
In-Reply-To: <1614d73f-72b0-44f2-8e34-0e6c58a1a375@xen.org>


Hi Julien,

Julien Grall <julien@xen.org> writes:

> Hi Volodymyr,
>
> On 19/09/2023 12:28, Volodymyr Babchuk wrote:
>> There is no need to invalidate cache entry because we just wrote into a
>> memory region. Writing itself guarantees that cache entry is valid.
>
> The goal of invalidate is to remove the line from the cache. So I
> don't quite understand the reasoning here.
>

Well, I may be wrong, but what is the goal in removing line from the
cache? As I see this, we want to be sure that ITS sees data written in
the memory, so we should flush a cache line. But why do we need to
remove it from CPU's cache?

-- 
WBR, Volodymyr

  reply	other threads:[~2023-09-19 14:36 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-09-19 11:28 [PATCH v1 0/3] ARM: ITS: implement TODO and fix issues with cache Volodymyr Babchuk
2023-09-19 11:28 ` [PATCH v1 1/3] ARM: GICv3 ITS: issue INVALL command after mapping host events Volodymyr Babchuk
2023-09-19 12:22   ` Julien Grall
2023-09-19 11:28 ` [PATCH v1 3/3] ARM: GICv3 ITS: flush all buffers, not just command queue Volodymyr Babchuk
2023-09-19 13:10   ` Julien Grall
2023-09-19 13:14     ` Julien Grall
2023-09-19 19:17       ` Stewart Hildebrand
2023-09-19 11:28 ` [PATCH v1 2/3] ARM: GICv3 ITS: do not invalidate memory while sending a command Volodymyr Babchuk
2023-09-19 13:02   ` Julien Grall
2023-09-19 14:36     ` Volodymyr Babchuk [this message]
2023-09-19 15:19       ` Julien Grall
2023-09-22  0:22         ` Volodymyr Babchuk
2023-09-22 10:31           ` Marc Zyngier
2023-09-22 22:02             ` Volodymyr Babchuk
2023-09-19 19:07 ` [PATCH v1 0/3] ARM: ITS: implement TODO and fix issues with cache Stewart Hildebrand

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=87fs3afcxb.fsf@epam.com \
    --to=volodymyr_babchuk@epam.com \
    --cc=bertrand.marquis@arm.com \
    --cc=julien@xen.org \
    --cc=sstabellini@kernel.org \
    --cc=stewart.hildebrand@amd.com \
    --cc=xen-devel@lists.xenproject.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 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.