From: Catalin Marinas <catalin.marinas@arm•com>
To: Jason Gunthorpe <jgg@nvidia•com>
Cc: Alexander Gordeev <agordeev@linux•ibm.com>,
Andrew Morton <akpm@linux-foundation•org>,
Christian Borntraeger <borntraeger@linux•ibm.com>,
Borislav Petkov <bp@alien8•de>,
Dave Hansen <dave.hansen@linux•intel.com>,
"David S. Miller" <davem@davemloft•net>,
Eric Dumazet <edumazet@google•com>,
Gerald Schaefer <gerald.schaefer@linux•ibm.com>,
Vasily Gorbik <gor@linux•ibm.com>,
Heiko Carstens <hca@linux•ibm.com>,
"H. Peter Anvin" <hpa@zytor•com>,
Justin Stitt <justinstitt@google•com>,
Jakub Kicinski <kuba@kernel•org>,
Leon Romanovsky <leon@kernel•org>,
linux-rdma@vger•kernel.org, linux-s390@vger•kernel.org,
llvm@lists•linux.dev, Ingo Molnar <mingo@redhat•com>,
Bill Wendling <morbo@google•com>,
Nathan Chancellor <nathan@kernel•org>,
Nick Desaulniers <ndesaulniers@google•com>,
netdev@vger•kernel.org, Paolo Abeni <pabeni@redhat•com>,
Salil Mehta <salil.mehta@huawei•com>,
Jijie Shao <shaojijie@huawei•com>,
Sven Schnelle <svens@linux•ibm.com>,
Thomas Gleixner <tglx@linutronix•de>,
x86@kernel•org, Yisen Zhuang <yisen.zhuang@huawei•com>,
Arnd Bergmann <arnd@arndb•de>,
Leon Romanovsky <leonro@mellanox•com>,
linux-arch@vger•kernel.org, linux-arm-kernel@lists•infradead.org,
Mark Rutland <mark.rutland@arm•com>,
Michael Guralnik <michaelgur@mellanox•com>,
patches@lists•linux.dev, Niklas Schnelle <schnelle@linux•ibm.com>,
Will Deacon <will@kernel•org>
Subject: Re: [PATCH 4/6] arm64/io: Provide a WC friendly __iowriteXX_copy()
Date: Tue, 27 Feb 2024 10:37:18 +0000 [thread overview]
Message-ID: <Zd27XtDg_NDzLXg-@arm.com> (raw)
In-Reply-To: <4-v1-38290193eace+5-mlx5_arm_wc_jgg@nvidia.com>
On Tue, Feb 20, 2024 at 09:17:08PM -0400, Jason Gunthorpe wrote:
> +/*
> + * This generates a memcpy that works on a from/to address which is aligned to
> + * bits. Count is in terms of the number of bits sized quantities to copy. It
> + * optimizes to use the STR groupings when possible so that it is WC friendly.
> + */
> +#define memcpy_toio_aligned(to, from, count, bits) \
> + ({ \
> + volatile u##bits __iomem *_to = to; \
> + const u##bits *_from = from; \
> + size_t _count = count; \
> + const u##bits *_end_from = _from + ALIGN_DOWN(_count, 8); \
> + \
> + for (; _from < _end_from; _from += 8, _to += 8) \
> + __const_memcpy_toio_aligned##bits(_to, _from, 8); \
> + if ((_count % 8) >= 4) { \
> + __const_memcpy_toio_aligned##bits(_to, _from, 4); \
> + _from += 4; \
> + _to += 4; \
> + } \
> + if ((_count % 4) >= 2) { \
> + __const_memcpy_toio_aligned##bits(_to, _from, 2); \
> + _from += 2; \
> + _to += 2; \
> + } \
> + if (_count % 2) \
> + __const_memcpy_toio_aligned##bits(_to, _from, 1); \
> + })
Do we actually need all this if count is not constant? If it's not
performance critical anywhere, I'd rather copy the generic
implementation, it's easier to read.
Otherwise, apart from the __raw_writeq() typo that Will mentioned, the
patch looks fine to me.
--
Catalin
next prev parent reply other threads:[~2024-02-27 10:37 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-21 1:17 [PATCH 0/6] Fix mlx5 write combining support on new ARM64 cores Jason Gunthorpe
2024-02-21 1:17 ` [PATCH 1/6] x86: Stop using weak symbols for __iowrite32_copy() Jason Gunthorpe
2024-02-21 1:17 ` [PATCH 2/6] s390: Implement __iowrite32_copy() Jason Gunthorpe
2024-02-21 1:17 ` [PATCH 3/6] s390: Stop using weak symbols for __iowrite64_copy() Jason Gunthorpe
2024-02-21 1:17 ` [PATCH 4/6] arm64/io: Provide a WC friendly __iowriteXX_copy() Jason Gunthorpe
2024-02-21 19:22 ` Will Deacon
2024-02-21 23:28 ` Jason Gunthorpe
2024-02-22 22:05 ` David Laight
2024-02-22 22:36 ` Jason Gunthorpe
2024-02-23 9:07 ` David Laight
2024-02-23 11:01 ` Niklas Schnelle
2024-02-23 11:05 ` David Laight
2024-02-23 12:53 ` Jason Gunthorpe
2024-02-23 11:38 ` Niklas Schnelle
2024-02-23 12:19 ` David Laight
2024-02-23 13:03 ` Jason Gunthorpe
2024-02-23 13:52 ` David Laight
2024-02-23 14:44 ` Jason Gunthorpe
2024-02-23 12:58 ` Jason Gunthorpe
2024-02-23 16:35 ` Niklas Schnelle
2024-02-23 17:05 ` Jason Gunthorpe
2024-02-27 10:37 ` Catalin Marinas [this message]
2024-02-28 23:06 ` Jason Gunthorpe
2024-02-29 10:24 ` Catalin Marinas
2024-02-29 13:28 ` Jason Gunthorpe
2024-02-29 10:33 ` Catalin Marinas
2024-02-29 13:29 ` Jason Gunthorpe
2024-03-01 18:52 ` Catalin Marinas
2024-02-21 1:17 ` [PATCH 5/6] net: hns3: Remove io_stop_wc() calls after __iowrite64_copy() Jason Gunthorpe
2024-02-22 0:57 ` Jijie Shao
2024-02-21 1:17 ` [PATCH 6/6] IB/mlx5: Use __iowrite64_copy() for write combining stores Jason Gunthorpe
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=Zd27XtDg_NDzLXg-@arm.com \
--to=catalin.marinas@arm$(echo .)com \
--cc=agordeev@linux$(echo .)ibm.com \
--cc=akpm@linux-foundation$(echo .)org \
--cc=arnd@arndb$(echo .)de \
--cc=borntraeger@linux$(echo .)ibm.com \
--cc=bp@alien8$(echo .)de \
--cc=dave.hansen@linux$(echo .)intel.com \
--cc=davem@davemloft$(echo .)net \
--cc=edumazet@google$(echo .)com \
--cc=gerald.schaefer@linux$(echo .)ibm.com \
--cc=gor@linux$(echo .)ibm.com \
--cc=hca@linux$(echo .)ibm.com \
--cc=hpa@zytor$(echo .)com \
--cc=jgg@nvidia$(echo .)com \
--cc=justinstitt@google$(echo .)com \
--cc=kuba@kernel$(echo .)org \
--cc=leon@kernel$(echo .)org \
--cc=leonro@mellanox$(echo .)com \
--cc=linux-arch@vger$(echo .)kernel.org \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
--cc=linux-rdma@vger$(echo .)kernel.org \
--cc=linux-s390@vger$(echo .)kernel.org \
--cc=llvm@lists$(echo .)linux.dev \
--cc=mark.rutland@arm$(echo .)com \
--cc=michaelgur@mellanox$(echo .)com \
--cc=mingo@redhat$(echo .)com \
--cc=morbo@google$(echo .)com \
--cc=nathan@kernel$(echo .)org \
--cc=ndesaulniers@google$(echo .)com \
--cc=netdev@vger$(echo .)kernel.org \
--cc=pabeni@redhat$(echo .)com \
--cc=patches@lists$(echo .)linux.dev \
--cc=salil.mehta@huawei$(echo .)com \
--cc=schnelle@linux$(echo .)ibm.com \
--cc=shaojijie@huawei$(echo .)com \
--cc=svens@linux$(echo .)ibm.com \
--cc=tglx@linutronix$(echo .)de \
--cc=will@kernel$(echo .)org \
--cc=x86@kernel$(echo .)org \
--cc=yisen.zhuang@huawei$(echo .)com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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