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From: Herbert Xu <herbert@gondor.apana.org.au>
To: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>,
	Arnd Bergmann <arnd@arndb.de>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Linux Memory Management List <linux-mm@kvack.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	"David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH 07/10] crypto: Use ARCH_DMA_MINALIGN instead of ARCH_KMALLOC_MINALIGN
Date: Fri, 15 Apr 2022 18:12:11 +0800	[thread overview]
Message-ID: <YllE+wWqP6F+1nwa@gondor.apana.org.au> (raw)
In-Reply-To: <CAMj1kXH=ybJWBzmMqkrkvyF8nM3UpTchUOq+oweW=BqW2TOyRw@mail.gmail.com>

On Fri, Apr 15, 2022 at 11:51:49AM +0200, Ard Biesheuvel wrote:
>
> That is the whole point, really: ARCH_DMA_MINALIGN==128 does not mean
> __ctx needs to be aligned to 128 bytes, it only means that it should
> not share a 128 byte cacheline with the preceding fields. So if
> kmalloc() returns buffers that are aligned to whatever alignment the
> platform requires (which will be 64 in most cases), the above
> arrangement ensures that, without requiring that CRYPTO_MINALIGN ==
> ARCH_DMA_MINALIGN.

What if they started sharing a cacheline with the subsequent object?
I guess you could add some more padding at the end though.

I could accept this as a temporary solution, if you volunteer to
modify all the affected drivers so we can get rid of this bandaid.

Thanks,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

WARNING: multiple messages have this Message-ID (diff)
From: Herbert Xu <herbert@gondor.apana.org.au>
To: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>,
	Arnd Bergmann <arnd@arndb.de>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Linux Memory Management List <linux-mm@kvack.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	"David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH 07/10] crypto: Use ARCH_DMA_MINALIGN instead of ARCH_KMALLOC_MINALIGN
Date: Fri, 15 Apr 2022 18:12:11 +0800	[thread overview]
Message-ID: <YllE+wWqP6F+1nwa@gondor.apana.org.au> (raw)
In-Reply-To: <CAMj1kXH=ybJWBzmMqkrkvyF8nM3UpTchUOq+oweW=BqW2TOyRw@mail.gmail.com>

On Fri, Apr 15, 2022 at 11:51:49AM +0200, Ard Biesheuvel wrote:
>
> That is the whole point, really: ARCH_DMA_MINALIGN==128 does not mean
> __ctx needs to be aligned to 128 bytes, it only means that it should
> not share a 128 byte cacheline with the preceding fields. So if
> kmalloc() returns buffers that are aligned to whatever alignment the
> platform requires (which will be 64 in most cases), the above
> arrangement ensures that, without requiring that CRYPTO_MINALIGN ==
> ARCH_DMA_MINALIGN.

What if they started sharing a cacheline with the subsequent object?
I guess you could add some more padding at the end though.

I could accept this as a temporary solution, if you volunteer to
modify all the affected drivers so we can get rid of this bandaid.

Thanks,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

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  parent reply	other threads:[~2022-04-15 10:12 UTC|newest]

Thread overview: 287+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-05 13:57 [PATCH 00/10] mm, arm64: Reduce ARCH_KMALLOC_MINALIGN below the cache line size Catalin Marinas
2022-04-05 13:57 ` Catalin Marinas
2022-04-05 13:57 ` [PATCH 01/10] mm/slab: Decouple ARCH_KMALLOC_MINALIGN from ARCH_DMA_MINALIGN Catalin Marinas
2022-04-05 13:57   ` Catalin Marinas
2022-04-05 23:59   ` Hyeonggon Yoo
2022-04-05 23:59     ` Hyeonggon Yoo
2022-04-06  7:29     ` Arnd Bergmann
2022-04-06  7:29       ` Arnd Bergmann
2022-04-06 12:09       ` Hyeonggon Yoo
2022-04-06 12:09         ` Hyeonggon Yoo
2022-04-06  8:53     ` Catalin Marinas
2022-04-06  8:53       ` Catalin Marinas
2022-04-06  2:01   ` kernel test robot
2022-04-06  8:56     ` Catalin Marinas
2022-04-06  8:56       ` Catalin Marinas
2022-04-06 12:18       ` [kbuild-all] " Chen, Rong A
2022-04-08  6:42   ` Hyeonggon Yoo
2022-04-08  6:42     ` Hyeonggon Yoo
2022-04-08  9:06     ` Hyeonggon Yoo
2022-04-08  9:06       ` Hyeonggon Yoo
2022-04-08  9:11     ` Catalin Marinas
2022-04-08  9:11       ` Catalin Marinas
2022-04-11 10:37   ` Hyeonggon Yoo
2022-04-11 10:37     ` Hyeonggon Yoo
2022-04-11 14:02     ` Catalin Marinas
2022-04-11 14:02       ` Catalin Marinas
2022-04-05 13:57 ` [PATCH 02/10] drivers/base: Use ARCH_DMA_MINALIGN instead of ARCH_KMALLOC_MINALIGN Catalin Marinas
2022-04-05 13:57   ` Catalin Marinas
2022-04-11 14:57   ` Andy Shevchenko
2022-04-11 14:57     ` Andy Shevchenko
2022-04-11 17:39     ` Catalin Marinas
2022-04-11 17:39       ` Catalin Marinas
2022-04-05 13:57 ` [PATCH 03/10] drivers/gpu: " Catalin Marinas
2022-04-05 13:57   ` Catalin Marinas
2022-04-05 13:57 ` [PATCH 04/10] drivers/md: " Catalin Marinas
2022-04-05 13:57   ` Catalin Marinas
2022-04-05 13:57 ` [PATCH 05/10] drivers/spi: " Catalin Marinas
2022-04-05 13:57   ` Catalin Marinas
2022-04-05 14:05   ` Mark Brown
2022-04-05 14:05     ` Mark Brown
2022-04-05 13:57 ` [PATCH 06/10] drivers/usb: " Catalin Marinas
2022-04-05 13:57   ` Catalin Marinas
2022-04-05 13:57 ` [PATCH 07/10] crypto: " Catalin Marinas
2022-04-05 13:57   ` Catalin Marinas
2022-04-05 22:57   ` Herbert Xu
2022-04-05 22:57     ` Herbert Xu
2022-04-06  6:53     ` Ard Biesheuvel
2022-04-06  6:53       ` Ard Biesheuvel
2022-04-06  8:49       ` Catalin Marinas
2022-04-06  8:49         ` Catalin Marinas
2022-04-06  9:41         ` Ard Biesheuvel
2022-04-06  9:41           ` Ard Biesheuvel
2022-04-07  4:30         ` Herbert Xu
2022-04-07  4:30           ` Herbert Xu
2022-04-07 11:01           ` Catalin Marinas
2022-04-07 11:01             ` Catalin Marinas
2022-04-07 11:40             ` Herbert Xu
2022-04-07 11:40               ` Herbert Xu
2022-04-07 16:28               ` Catalin Marinas
2022-04-07 16:28                 ` Catalin Marinas
2022-04-08  3:25                 ` Herbert Xu
2022-04-08  3:25                   ` Herbert Xu
2022-04-08  9:04                   ` Catalin Marinas
2022-04-08  9:04                     ` Catalin Marinas
2022-04-08  9:11                     ` Herbert Xu
2022-04-08  9:11                       ` Herbert Xu
2022-04-12  9:32                       ` Catalin Marinas
2022-04-12  9:32                         ` Catalin Marinas
2022-04-12  9:40                         ` Herbert Xu
2022-04-12  9:40                           ` Herbert Xu
2022-04-12 10:02                           ` Catalin Marinas
2022-04-12 10:02                             ` Catalin Marinas
2022-04-12 10:18                             ` Herbert Xu
2022-04-12 10:18                               ` Herbert Xu
2022-04-12 12:31                               ` Catalin Marinas
2022-04-12 12:31                                 ` Catalin Marinas
2022-04-12 22:01                                 ` Ard Biesheuvel
2022-04-12 22:01                                   ` Ard Biesheuvel
2022-04-13  8:47                                   ` Catalin Marinas
2022-04-13  8:47                                     ` Catalin Marinas
2022-04-13 19:53                                     ` Linus Torvalds
2022-04-13 19:53                                       ` Linus Torvalds
2022-04-14  5:38                                       ` Greg Kroah-Hartman
2022-04-14  5:38                                         ` Greg Kroah-Hartman
2022-04-14 13:52                                         ` Ard Biesheuvel
2022-04-14 13:52                                           ` Ard Biesheuvel
2022-04-14 14:27                                           ` Greg Kroah-Hartman
2022-04-14 14:27                                             ` Greg Kroah-Hartman
2022-04-14 14:36                                             ` Ard Biesheuvel
2022-04-14 14:36                                               ` Ard Biesheuvel
2022-04-14 14:52                                               ` Greg Kroah-Hartman
2022-04-14 14:52                                                 ` Greg Kroah-Hartman
2022-04-14 15:01                                                 ` Ard Biesheuvel
2022-04-14 15:01                                                   ` Ard Biesheuvel
2022-04-14 15:10                                                   ` Ard Biesheuvel
2022-04-14 15:10                                                     ` Ard Biesheuvel
2022-04-14 19:49                                       ` Catalin Marinas
2022-04-14 19:49                                         ` Catalin Marinas
2022-04-14 22:25                                         ` Linus Torvalds
2022-04-14 22:25                                           ` Linus Torvalds
2022-04-15  6:03                                           ` Ard Biesheuvel
2022-04-15  6:03                                             ` Ard Biesheuvel
2022-04-15 11:09                                           ` Arnd Bergmann
2022-04-15 11:09                                             ` Arnd Bergmann
2022-04-16  9:42                                           ` Catalin Marinas
2022-04-16  9:42                                             ` Catalin Marinas
2022-04-20 19:07                                           ` Catalin Marinas
2022-04-20 19:07                                             ` Catalin Marinas
2022-04-20 19:33                                             ` Linus Torvalds
2022-04-20 19:33                                               ` Linus Torvalds
2022-04-14 14:30                                     ` Ard Biesheuvel
2022-04-14 14:30                                       ` Ard Biesheuvel
2022-04-15  6:51                                     ` Herbert Xu
2022-04-15  6:51                                       ` Herbert Xu
2022-04-15  7:49                                       ` Ard Biesheuvel
2022-04-15  7:49                                         ` Ard Biesheuvel
2022-04-15  7:51                                         ` Herbert Xu
2022-04-15  7:51                                           ` Herbert Xu
2022-04-15  8:05                                           ` Ard Biesheuvel
2022-04-15  8:05                                             ` Ard Biesheuvel
2022-04-15  8:12                                             ` Herbert Xu
2022-04-15  8:12                                               ` Herbert Xu
2022-04-15  9:51                                               ` Ard Biesheuvel
2022-04-15  9:51                                                 ` Ard Biesheuvel
2022-04-15 10:04                                                 ` Ard Biesheuvel
2022-04-15 10:04                                                   ` Ard Biesheuvel
2022-04-15 10:12                                                 ` Herbert Xu [this message]
2022-04-15 10:12                                                   ` Herbert Xu
2022-04-15 10:22                                                   ` Ard Biesheuvel
2022-04-15 10:22                                                     ` Ard Biesheuvel
2022-04-15 10:45                                                     ` Herbert Xu
2022-04-15 10:45                                                       ` Herbert Xu
2022-04-15 11:38                                                       ` Ard Biesheuvel
2022-04-15 11:38                                                         ` Ard Biesheuvel
2022-04-17  8:08                                                         ` Herbert Xu
2022-04-17  8:08                                                           ` Herbert Xu
2022-04-17  8:31                                                           ` Catalin Marinas
2022-04-17  8:31                                                             ` Catalin Marinas
2022-04-17  8:35                                                             ` Herbert Xu
2022-04-17  8:35                                                               ` Herbert Xu
2022-04-17  8:50                                                               ` Catalin Marinas
2022-04-17  8:50                                                                 ` Catalin Marinas
2022-04-17  8:58                                                                 ` Herbert Xu
2022-04-17  8:58                                                                   ` Herbert Xu
2022-04-17 16:30                                                                   ` Catalin Marinas
2022-04-17 16:30                                                                     ` Catalin Marinas
2022-04-18  8:37                                                                     ` Herbert Xu
2022-04-18  8:37                                                                       ` Herbert Xu
2022-04-18  9:19                                                                       ` Catalin Marinas
2022-04-18  9:19                                                                         ` Catalin Marinas
2022-04-18 16:44                                                                       ` Catalin Marinas
2022-04-18 16:44                                                                         ` Catalin Marinas
2022-04-19 21:50                                                                         ` Ard Biesheuvel
2022-04-19 21:50                                                                           ` Ard Biesheuvel
2022-04-20 10:36                                                                           ` Catalin Marinas
2022-04-20 10:36                                                                             ` Catalin Marinas
2022-04-20 11:29                                                                           ` Arnd Bergmann
2022-04-20 11:29                                                                             ` Arnd Bergmann
2022-04-21  7:20                                                                             ` Christoph Hellwig
2022-04-21  7:20                                                                               ` Christoph Hellwig
2022-04-21  7:36                                                                               ` Arnd Bergmann
2022-04-21  7:36                                                                                 ` Arnd Bergmann
2022-04-21  7:44                                                                                 ` Christoph Hellwig
2022-04-21  7:44                                                                                   ` Christoph Hellwig
2022-04-21  8:05                                                                               ` Ard Biesheuvel
2022-04-21  8:05                                                                                 ` Ard Biesheuvel
2022-04-21 11:06                                                                               ` Catalin Marinas
2022-04-21 11:06                                                                                 ` Catalin Marinas
2022-04-21 12:28                                                                                 ` Arnd Bergmann
2022-04-21 12:28                                                                                   ` Arnd Bergmann
2022-04-21 13:25                                                                                   ` Catalin Marinas
2022-04-21 13:25                                                                                     ` Catalin Marinas
2022-04-21 13:47                                                                                     ` Arnd Bergmann
2022-04-21 13:47                                                                                       ` Arnd Bergmann
2022-04-21 14:44                                                                                       ` Catalin Marinas
2022-04-21 14:44                                                                                         ` Catalin Marinas
2022-04-21 14:47                                                                                         ` Arnd Bergmann
2022-04-21 14:47                                                                                           ` Arnd Bergmann
2022-05-10 11:03                                                                       ` [RFC PATCH 0/7] crypto: Add helpers for allocating with DMA alignment Herbert Xu
2022-05-10 11:03                                                                         ` Herbert Xu
2022-05-10 11:07                                                                         ` [RFC PATCH 1/7] crypto: Prepare to move crypto_tfm_ctx Herbert Xu
2022-05-10 11:07                                                                           ` Herbert Xu
2022-05-10 11:07                                                                         ` [RFC PATCH 2/7] crypto: api - Add crypto_tfm_ctx_dma Herbert Xu
2022-05-10 11:07                                                                           ` Herbert Xu
2022-05-10 17:10                                                                           ` Catalin Marinas
2022-05-10 17:10                                                                             ` Catalin Marinas
2022-05-12  3:57                                                                             ` Herbert Xu
2022-05-12  3:57                                                                               ` Herbert Xu
2022-05-10 11:07                                                                         ` [RFC PATCH 3/7] crypto: aead - Add ctx helpers with DMA alignment Herbert Xu
2022-05-10 11:07                                                                           ` Herbert Xu
2022-05-10 11:07                                                                         ` [RFC PATCH 4/7] crypto: hash " Herbert Xu
2022-05-10 11:07                                                                           ` Herbert Xu
2022-05-10 11:07                                                                         ` [RFC PATCH 5/7] crypto: skcipher " Herbert Xu
2022-05-10 11:07                                                                           ` Herbert Xu
2022-05-10 11:07                                                                         ` [RFC PATCH 6/7] crypto: api - Increase MAX_ALGAPI_ALIGNMASK to 127 Herbert Xu
2022-05-10 11:07                                                                           ` Herbert Xu
2022-05-10 11:07                                                                         ` [RFC PATCH 7/7] crypto: caam - Explicitly request DMA alignment Herbert Xu
2022-05-10 11:07                                                                           ` Herbert Xu
2022-04-15 12:18                                             ` [PATCH 07/10] crypto: Use ARCH_DMA_MINALIGN instead of ARCH_KMALLOC_MINALIGN Catalin Marinas
2022-04-15 12:18                                               ` Catalin Marinas
2022-04-15 12:25                                               ` Ard Biesheuvel
2022-04-15 12:25                                                 ` Ard Biesheuvel
2022-04-15  9:51                                           ` Catalin Marinas
2022-04-15  9:51                                             ` Catalin Marinas
2022-04-15 12:31                                             ` Catalin Marinas
2022-04-15 12:31                                               ` Catalin Marinas
2022-04-17  8:11                                               ` Herbert Xu
2022-04-17  8:11                                                 ` Herbert Xu
2022-04-17  8:38                                                 ` Catalin Marinas
2022-04-17  8:38                                                   ` Catalin Marinas
2022-04-17  8:43                                                   ` Herbert Xu
2022-04-17  8:43                                                     ` Herbert Xu
2022-04-17 16:29                                                     ` Catalin Marinas
2022-04-17 16:29                                                       ` Catalin Marinas
2022-07-15 22:23                                                       ` Isaac Manjarres
2022-07-15 22:23                                                         ` Isaac Manjarres
2022-07-16  3:25                                                         ` Herbert Xu
2022-07-16  3:25                                                           ` Herbert Xu
2022-07-18 17:53                                                           ` Catalin Marinas
2022-07-18 17:53                                                             ` Catalin Marinas
2022-09-21  0:47                                                             ` Isaac Manjarres
2022-09-21  0:47                                                               ` Isaac Manjarres
2022-09-30 18:32                                                               ` Catalin Marinas
2022-09-30 18:32                                                                 ` Catalin Marinas
2022-09-30 19:35                                                                 ` Linus Torvalds
2022-09-30 19:35                                                                   ` Linus Torvalds
2022-10-01 22:29                                                                   ` Catalin Marinas
2022-10-01 22:29                                                                     ` Catalin Marinas
2022-10-02 17:00                                                                     ` Linus Torvalds
2022-10-02 17:00                                                                       ` Linus Torvalds
2022-10-02 22:08                                                                       ` Ard Biesheuvel
2022-10-02 22:08                                                                         ` Ard Biesheuvel
2022-10-02 22:24                                                                         ` Linus Torvalds
2022-10-02 22:24                                                                           ` Linus Torvalds
2022-10-03 17:39                                                                           ` Catalin Marinas
2022-10-03 17:39                                                                             ` Catalin Marinas
2022-10-12 17:45                                                                 ` Isaac Manjarres
2022-10-12 17:45                                                                   ` Isaac Manjarres
2022-10-13 16:57                                                                   ` Catalin Marinas
2022-10-13 16:57                                                                     ` Catalin Marinas
2022-10-13 18:58                                                                     ` Saravana Kannan
2022-10-13 18:58                                                                       ` Saravana Kannan
2022-10-14 16:25                                                                       ` Catalin Marinas
2022-10-14 16:25                                                                         ` Catalin Marinas
2022-10-14 20:23                                                                         ` Saravana Kannan
2022-10-14 20:23                                                                           ` Saravana Kannan
2022-10-14 20:44                                                                           ` Linus Torvalds
2022-10-14 20:44                                                                             ` Linus Torvalds
2022-10-16 21:37                                                                             ` Catalin Marinas
2022-10-16 21:37                                                                               ` Catalin Marinas
2022-04-12 10:20                             ` Catalin Marinas
2022-04-12 10:20                               ` Catalin Marinas
2022-04-07  6:14   ` Muchun Song
2022-04-07  6:14     ` Muchun Song
2022-04-07  9:25     ` Catalin Marinas
2022-04-07  9:25       ` Catalin Marinas
2022-04-07 10:00       ` Muchun Song
2022-04-07 10:00         ` Muchun Song
2022-04-07 11:06         ` Catalin Marinas
2022-04-07 11:06           ` Catalin Marinas
2022-04-05 13:57 ` [PATCH 08/10] mm/slab: Allow dynamic kmalloc() minimum alignment Catalin Marinas
2022-04-05 13:57   ` Catalin Marinas
2022-04-07  3:46   ` Hyeonggon Yoo
2022-04-07  3:46     ` Hyeonggon Yoo
2022-04-07  8:50     ` Catalin Marinas
2022-04-07  8:50       ` Catalin Marinas
2022-04-07  9:18       ` Hyeonggon Yoo
2022-04-07  9:18         ` Hyeonggon Yoo
2022-04-07  9:35         ` Catalin Marinas
2022-04-07  9:35           ` Catalin Marinas
2022-04-07 12:26           ` Hyeonggon Yoo
2022-04-07 12:26             ` Hyeonggon Yoo
2022-04-11 11:55   ` Hyeonggon Yoo
2022-04-11 11:55     ` Hyeonggon Yoo
2022-04-05 13:57 ` [PATCH 09/10] mm/slab: Simplify create_kmalloc_cache() args and make it static Catalin Marinas
2022-04-05 13:57   ` Catalin Marinas
2022-04-06  5:35   ` kernel test robot
2022-04-06  8:57     ` Catalin Marinas
2022-04-06  8:57       ` Catalin Marinas
2022-04-05 13:57 ` [PATCH 10/10] arm64: Enable dynamic kmalloc() minimum alignment Catalin Marinas
2022-04-05 13:57   ` Catalin Marinas
2022-04-07 14:40 ` [PATCH 00/10] mm, arm64: Reduce ARCH_KMALLOC_MINALIGN below the cache line size Vlastimil Babka
2022-04-07 14:40   ` Vlastimil Babka
2022-04-07 17:48   ` Catalin Marinas
2022-04-07 17:48     ` Catalin Marinas
2022-04-08 14:37     ` Vlastimil Babka
2022-04-08 14:37       ` Vlastimil Babka

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