All of lore.kernel.org
 help / color / mirror / Atom feed
From: Arnd Bergmann <arnd@arndb.de>
To: Will Deacon <will.deacon@arm.com>
Cc: linux-arch <linux-arch@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	andrew.murray@arm.com, Catalin Marinas <catalin.marinas@arm.com>,
	linux-riscv@lists.infradead.org,
	Palmer Dabbelt <palmer@sifive.com>,
	Albert Ou <aou@eecs.berkeley.edu>
Subject: Re: [PATCH 1/2] asm-generic/io: Pass result on inX() accessor to __io_par()
Date: Tue, 12 Feb 2019 12:55:17 +0100	[thread overview]
Message-ID: <CAK8P3a1gmJTt+jdTbdSYZ0z43qodxf+co757K1-Hq1mj4fCqQA@mail.gmail.com> (raw)
In-Reply-To: <20190211174544.4302-2-will.deacon@arm.com>

On Mon, Feb 11, 2019 at 6:45 PM Will Deacon <will.deacon@arm.com> wrote:
>
> The inX() I/O accessors must enforce ordering against subsequent calls
> to the delay() routines, so that a read-back from a device can be used
> to postpone a subsequent write to the same device.
>
> On some architectures, including arm64, this ordering can only be
> achieved by creating a dependency on the value returned by the inX()
> operation, so we need to pass the value we read to the __io_par()
> macro in this case.
>
> Reported-by: Andrew Murray <andrew.murray@arm.com>
> Signed-off-by: Will Deacon <will.deacon@arm.com>
> ---
>  include/asm-generic/io.h | 8 ++++----

For changing the asm-generic file in the arm64 tree,

Acked-by: Arnd Bergmann <arnd@arndb.de>

For all I can see, this should not conflict with the usage of the
same macros on RISC-V, though it does make add a significant
difference, so I'd like to see an Ack from the RISC-V folks as
well (added to Cc), or possibly a change to arch/riscv/include/asm/io.h
to do a corresponding change.

       Arnd

WARNING: multiple messages have this Message-ID (diff)
From: Arnd Bergmann <arnd@arndb.de>
To: Will Deacon <will.deacon@arm.com>
Cc: linux-arch <linux-arch@vger.kernel.org>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Palmer Dabbelt <palmer@sifive.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	andrew.murray@arm.com, linux-riscv@lists.infradead.org
Subject: Re: [PATCH 1/2] asm-generic/io: Pass result on inX() accessor to __io_par()
Date: Tue, 12 Feb 2019 12:55:17 +0100	[thread overview]
Message-ID: <CAK8P3a1gmJTt+jdTbdSYZ0z43qodxf+co757K1-Hq1mj4fCqQA@mail.gmail.com> (raw)
In-Reply-To: <20190211174544.4302-2-will.deacon@arm.com>

On Mon, Feb 11, 2019 at 6:45 PM Will Deacon <will.deacon@arm.com> wrote:
>
> The inX() I/O accessors must enforce ordering against subsequent calls
> to the delay() routines, so that a read-back from a device can be used
> to postpone a subsequent write to the same device.
>
> On some architectures, including arm64, this ordering can only be
> achieved by creating a dependency on the value returned by the inX()
> operation, so we need to pass the value we read to the __io_par()
> macro in this case.
>
> Reported-by: Andrew Murray <andrew.murray@arm.com>
> Signed-off-by: Will Deacon <will.deacon@arm.com>
> ---
>  include/asm-generic/io.h | 8 ++++----

For changing the asm-generic file in the arm64 tree,

Acked-by: Arnd Bergmann <arnd@arndb.de>

For all I can see, this should not conflict with the usage of the
same macros on RISC-V, though it does make add a significant
difference, so I'd like to see an Ack from the RISC-V folks as
well (added to Cc), or possibly a change to arch/riscv/include/asm/io.h
to do a corresponding change.

       Arnd

_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

  reply	other threads:[~2019-02-12 11:55 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-11 17:45 [PATCH 0/2] Ensure inX() is ordered wrt delay() routines Will Deacon
2019-02-11 17:45 ` [PATCH 1/2] asm-generic/io: Pass result on inX() accessor to __io_par() Will Deacon
2019-02-12 11:55   ` Arnd Bergmann [this message]
2019-02-12 11:55     ` Arnd Bergmann
2019-02-13 17:46     ` Will Deacon
2019-02-13 17:46       ` Will Deacon
2019-02-13 20:59       ` Arnd Bergmann
2019-02-13 20:59         ` Arnd Bergmann
2019-02-13 21:57         ` Palmer Dabbelt
2019-02-13 21:57           ` Palmer Dabbelt
2019-02-18 15:56           ` Will Deacon
2019-02-18 15:56             ` Will Deacon
2019-02-11 17:45 ` [PATCH 2/2] arm64: io: Hook up __io_par() for inX() ordering Will Deacon
2019-02-12 10:42   ` Geert Uytterhoeven
2019-02-13 17:25     ` Will Deacon

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=CAK8P3a1gmJTt+jdTbdSYZ0z43qodxf+co757K1-Hq1mj4fCqQA@mail.gmail.com \
    --to=arnd@arndb.de \
    --cc=andrew.murray@arm.com \
    --cc=aou@eecs.berkeley.edu \
    --cc=catalin.marinas@arm.com \
    --cc=linux-arch@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-riscv@lists.infradead.org \
    --cc=palmer@sifive.com \
    --cc=will.deacon@arm.com \
    /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.