From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 31ED0C77B7C for ; Thu, 26 Jun 2025 01:49:25 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C554E6B00A8; Wed, 25 Jun 2025 21:49:24 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C06286B00B0; Wed, 25 Jun 2025 21:49:24 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AF57D6B00B5; Wed, 25 Jun 2025 21:49:24 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 9DD306B00A8 for ; Wed, 25 Jun 2025 21:49:24 -0400 (EDT) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 6740B14086E for ; Thu, 26 Jun 2025 01:49:24 +0000 (UTC) X-FDA: 83595869448.22.0B00449 Received: from mail-pl1-f169.google.com (mail-pl1-f169.google.com [209.85.214.169]) by imf21.hostedemail.com (Postfix) with ESMTP id 69A841C0006 for ; Thu, 26 Jun 2025 01:49:22 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=iDWc81K0; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf21.hostedemail.com: domain of bagasdotme@gmail.com designates 209.85.214.169 as permitted sender) smtp.mailfrom=bagasdotme@gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1750902562; a=rsa-sha256; cv=none; b=FbESM5Q1l0/4NxmNn4Mq7JAuIUlOeWiZ/TeDRFXphayNPQkBCDH4re94K355Rnl7dLV0yd odS7lLgCbbSPRWRam1jTYkzeNKk7GHFCrkM152Ld1YlOQ72GR3zGOpjppgvbtPk+wrjEiw XQ5VrjYeahF01umqB4vEswnTo8unvE4= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=iDWc81K0; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf21.hostedemail.com: domain of bagasdotme@gmail.com designates 209.85.214.169 as permitted sender) smtp.mailfrom=bagasdotme@gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1750902562; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=+Nz6gceMsEAjGJ9EuhScUNZ07PGuYbVAvvgZ2k08rxc=; b=Px+3t/qZhXtAlGDhGB9t3YHM1Vj3jT+YEP5sXPONyNeqjHaRDopEN8EizdaYIe6EcgSyh8 scvTFaQIqSM6LPgjoqwCK5G8LhtTm4qctX9O9dcqP/XYOU4hDnYAwzf9Y5Dkm9gR5xLggt RkwOV7eH/f5gDzlGdOvot0+T6tRd8to= Received: by mail-pl1-f169.google.com with SMTP id d9443c01a7336-2352400344aso5513005ad.2 for ; Wed, 25 Jun 2025 18:49:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1750902561; x=1751507361; darn=kvack.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=+Nz6gceMsEAjGJ9EuhScUNZ07PGuYbVAvvgZ2k08rxc=; b=iDWc81K0OY+a+0SwcmXK0qJrQJmiZvNCNJl/D6MicIzmwzr/cA02StbmMacr2g8Zaa 6UX4kCtfJyNwTbIfF89uvjWLLoYMFH3iafQb/OpzcqMBsHTp4bx41NLnW/MBHBPR+gSj sCU8q5sZTbfU0TbErl4q+KaTb2PFr5AxnaE749jQTlolRx9IcMA2NAsOZJBBBThv7Xea 2WGfg3JXSXpUblDG4Ry0DmDcLy4fUMu/A9dcBWefgG7hT9gj/Km0+NH3ZRkwLIXresLJ sXN5Ce0yd/ZkzR9nucFNc9CS/qLZckg3i6MS1rlVO/LFuoYGzkgWi7E3/0rTI7Q6q6zJ 8xwQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1750902561; x=1751507361; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=+Nz6gceMsEAjGJ9EuhScUNZ07PGuYbVAvvgZ2k08rxc=; b=PdQB5C6HKFuI5MuglMrgAuGG8ZFqaH4wJLt7I3jZJMdeBAhBrAXdLi7mtWaW1y1jFS t2vVA9erubSDxDd4l27bPDmGumoCDTFWhQL1dTAEKRhVYtKwT5WiBx1JP1XWXBYCW7uw FVgSeMihFCmJ0ho9ILXyNswkcjqNfp30JuScgcDvH0JrNigHP5cRr77mC1iLjC3laCZz H2Lblrpjq4kwrTLwfQXBCCJWzONuELN7h+iwgf6xtw5eMtAdSxYo8bJGsWks9spnsCkg S6azVLopgukhCidyCBa41ZxrqOtCvEgiVn2zcrkQGgI93EP7TILdJIfwb0Niarotsuvo UEug== X-Forwarded-Encrypted: i=1; AJvYcCVCtPoJuFKRWRxG9ZbQ3Ff5CQagHQ8vHQIeWIAAlN/LN5CPonBCWUpywCqllRBG1bzaD1qTpn8VFw==@kvack.org X-Gm-Message-State: AOJu0Yy75oGVI4v/FnpDDNsaFb5f9V0LLzz3C77GfAPCWHfM6XBAp7zn yt7GC+sDsImvTjjAT7f05MzLYDhm9t4dAZ7NYcz6hsLbn4Zyfn7AMJU7 X-Gm-Gg: ASbGncvhqcaP+YUzdKKy/LGGp7Xg+Lh5siiblx1YBn9VRDuIf28gqP8dirUBZ8DAvUY rKuK8gzjeYStAL8BZ5gZJmN7riidT13xJKoqgPqW9YtCLjY0+iXKuXvFtNYetMsozdwUQOEGHed Wnr2lGuXGmZglh/bdU7JXYH1uXqTFkiqDx3zK0kdADB4KrltH40oFgjqUOIP0HsuqLJAFrcpT6P bj6iLLXc+yzzPY0P9JysLnQSQCMMc8zjnJkJRVgDrYQnJVWN2avkMQg+we0Ko6RFGfWnrpJJmdt GEwN4Ac5nrwUiQFFqWBTJTUU0ok9QWHGWVcFzurpTMyJTX2lJYFABTCzWU4BXQ== X-Google-Smtp-Source: AGHT+IHXr54nVYRwcPKxGrk70SCFElkQ98A/GfmX+sR0hW3/0w1cdSyA/LFCaOPKMrHSSlSRW5YyxQ== X-Received: by 2002:a17:902:d492:b0:224:76f:9e4a with SMTP id d9443c01a7336-238c8725bcfmr18693275ad.14.1750902561243; Wed, 25 Jun 2025 18:49:21 -0700 (PDT) Received: from archie.me ([103.124.138.155]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-237d8393292sm143565065ad.13.2025.06.25.18.49.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Jun 2025 18:49:20 -0700 (PDT) Received: by archie.me (Postfix, from userid 1000) id 1E7A0420A9A6; Thu, 26 Jun 2025 08:49:17 +0700 (WIB) Date: Thu, 26 Jun 2025 08:49:17 +0700 From: Bagas Sanjaya To: Petr Tesarik , Jonathan Corbet , Morton Cc: Marek Szyprowski , Leon Romanovsky , Keith Busch , Caleb Sander Mateos , Sagi Grimberg , Jens Axboe , John Garry , "open list:DOCUMENTATION" , open list , "open list:MEMORY MANAGEMENT" Subject: Re: [PATCH 7/8] docs: dma-api: update streaming DMA API physical address constraints Message-ID: References: <20250624133923.1140421-1-ptesarik@suse.com> <20250624133923.1140421-8-ptesarik@suse.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="uuwR7Yn/uQf6oyy6" Content-Disposition: inline In-Reply-To: <20250624133923.1140421-8-ptesarik@suse.com> X-Rspam-User: X-Rspamd-Queue-Id: 69A841C0006 X-Rspamd-Server: rspam10 X-Stat-Signature: tyxaeyq9qkcmjcg5d94yyd1izy5wdcji X-HE-Tag: 1750902562-545576 X-HE-Meta: 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 PPZ8+iRW gZ18FPQzTpq5SV8xxtHztoL8+suRG9incbePVYy6PyyeszS81qxPY6McrmwtqJs/K2c8zb1PvKJ8DTnzVbprCxV1vtTFTwzDs3V3UzlbxZ94IBkl6RcspM9GpYSVqM/Zwy7DQDdENL8aXEXteQvydGkQtOkDBykiRgaHrCWmyPJZRsM5io/IafA2+Xhm8Ylv5HoZQQdDga8tEZacbvmYWpfZuitoKvPoFwnWFP576dNrQwf7pLFmfV8qleKv4HIaMk4Kgk5H3FrNpOGwk+7Yc9Yzo1CXFLKt8GnAH/EgHbi9eEoLZjMPGze1k8OoGnxPKojEpKDUbGuK6pKooVdOthcEJkLjA5+TF8KeaYb9ntoSdJYPnJdznGQLuK38GU/ioTBMRqTc4HUL052BDH/+5vffqEAOtU9QiCn1GQQK29paIV88Nbg7ulvQ/SFAIipwmn91hdPwM2eGyRWI6MpaxpcpHoGObd1cESp9c X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: --uuwR7Yn/uQf6oyy6 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Jun 24, 2025 at 03:39:22PM +0200, Petr Tesarik wrote: > diff --git a/Documentation/core-api/dma-api.rst b/Documentation/core-api/= dma-api.rst > index cd432996949c..65132ec88104 100644 > --- a/Documentation/core-api/dma-api.rst > +++ b/Documentation/core-api/dma-api.rst > @@ -210,18 +210,12 @@ DMA_BIDIRECTIONAL direction isn't known > this API should be obtained from sources which guarantee it to be > physically contiguous (like kmalloc). > =20 > - Further, the DMA address of the memory must be within the dma_mask of > - the device. To ensure that the memory allocated by kmalloc is within > - the dma_mask, the driver may specify various platform-dependent flags > - to restrict the DMA address range of the allocation (e.g., on x86, > - GFP_DMA guarantees to be within the first 16MB of available DMA > - addresses, as required by ISA devices). > - > - Note also that the above constraints on physical contiguity and > - dma_mask may not apply if the platform has an IOMMU (a device which > - maps an I/O DMA address to a physical memory address). However, to be > - portable, device driver writers may *not* assume that such an IOMMU > - exists. > + Mapping may also fail if the memory is not within the DMA mask of the > + device. However, this constraint does not apply if the platform has > + an IOMMU (a device which maps an I/O DMA address to a physical memory > + address), or the kernel is configured with SWIOTLB (bounce buffers). > + It is reasonable to assume that at least one of these mechanisms > + allows streaming DMA to any physical address. > =20 > .. warning:: > =20 LGTM, thanks! Reviewed-by: Bagas Sanjaya --=20 An old man doll... just what I always wanted! - Clara --uuwR7Yn/uQf6oyy6 Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQSSYQ6Cy7oyFNCHrUH2uYlJVVFOowUCaFynHQAKCRD2uYlJVVFO owLhAPwNWaolM6tIUBgUQIggjkqtrYfI7Vp3IWaC9LRBQIbVqQEA882rDH9Q47Ao rabejogHBB+Mow82kYXL+8TfZ0CCfgE= =bn24 -----END PGP SIGNATURE----- --uuwR7Yn/uQf6oyy6--