From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailout2.w1.samsung.com (mailout2.w1.samsung.com [210.118.77.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F20C82C11F5 for ; Mon, 24 Nov 2025 18:11:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=210.118.77.12 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764007881; cv=none; b=Ru9c+gTMv+o+C9o517btEuXIaLjkwqJhLUEPKyzzqPhbBmA/wQ7sue6KsCExDy/Gz//WFXpEgLzMoxIO8jrap5WuYfbXwxyb6chkXtypqTmL3Wxj39PDxSsVhA/G8kkUBuEWAXhXIN42xPGn11giIrXAv4Gfi5P/dj67Rw7YkA8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764007881; c=relaxed/simple; bh=V3lKiCOqTmuSyHMCBiRRzu0/4INcRYOmWSJXw1oQ7xY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:From:In-Reply-To: Content-Type:References; b=ncVV45hNilZ7EVctYjBLX2zRAbl+2MImrc2JM+sixiXMik3wWpvKM0IrwbPGQbPp4vkzl+CuNFOVX1ERD2xaiI9R59l6C3/tLihgcKPbmezgcBc/fOaVHPsWmZ4gu4vAO418EGSBL5VySSGggHPGOlRDf/D16aQTg2CeFjFYFG0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=samsung.com; spf=pass smtp.mailfrom=samsung.com; dkim=pass (1024-bit key) header.d=samsung.com header.i=@samsung.com header.b=MoVOKuxN; arc=none smtp.client-ip=210.118.77.12 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=samsung.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=samsung.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=samsung.com header.i=@samsung.com header.b="MoVOKuxN" Received: from eucas1p1.samsung.com (unknown [182.198.249.206]) by mailout2.w1.samsung.com (KnoxPortal) with ESMTP id 20251124181116euoutp02d28df0d7f7ae3f71fa49c4b50d2851c1~7A9EzjH7O2089620896euoutp02Z for ; Mon, 24 Nov 2025 18:11:16 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout2.w1.samsung.com 20251124181116euoutp02d28df0d7f7ae3f71fa49c4b50d2851c1~7A9EzjH7O2089620896euoutp02Z DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1764007876; bh=mAKEXc7Po5ZcQ8NHiJ/6YgIjS+LUifyXpnXyqV/E/2I=; h=Date:Subject:To:Cc:From:In-Reply-To:References:From; b=MoVOKuxNGqVDeVT0yIHn45anwe5rIfm5oBvd0Acai2JzB0E7TmmbJ5TsMrz6n/mHm mHz0iuvdGe8j28YB5ykYU9GPrewVcVVX1gca64ezZGlspj2oz6wKr6cKC5Q8tbHRM+ w/9zfZjRlrVgXWZ1qf32pCj26qfg8HMxviOMO3uo= Received: from eusmtip1.samsung.com (unknown [203.254.199.221]) by eucas1p1.samsung.com (KnoxPortal) with ESMTPA id 20251124181115eucas1p194eb1fe47ad6b90c5e22bd8ed2e0bfbb~7A9EJtcS63164331643eucas1p1C; Mon, 24 Nov 2025 18:11:15 +0000 (GMT) Received: from [106.210.134.192] (unknown [106.210.134.192]) by eusmtip1.samsung.com (KnoxPortal) with ESMTPA id 20251124181113eusmtip137fc2398eb412a7d397c6aee5961bac6~7A9Cu-DoB1470614706eusmtip1-; Mon, 24 Nov 2025 18:11:13 +0000 (GMT) Message-ID: Date: Mon, 24 Nov 2025 19:11:13 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Betterbird (Windows) Subject: Re: [RFC PATCH 5/5] dma-mapping: Allow batched DMA sync operations if supported by the arch To: Barry Song <21cnbao@gmail.com> Cc: ada.coupriediaz@arm.com, anshuman.khandual@arm.com, ardb@kernel.org, catalin.marinas@arm.com, iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, maz@kernel.org, robin.murphy@arm.com, ryan.roberts@arm.com, surenb@google.com, v-songbaohua@oppo.com, will@kernel.org, zhengtangquan@oppo.com Content-Language: en-US From: Marek Szyprowski In-Reply-To: <20251121232807.40491-1-21cnbao@gmail.com> Content-Transfer-Encoding: 8bit X-CMS-MailID: 20251124181115eucas1p194eb1fe47ad6b90c5e22bd8ed2e0bfbb X-Msg-Generator: CA Content-Type: text/plain; charset="utf-8" X-RootMTR: 20251121232820eucas1p13f5798a2d8c5049ae7cadc62cce63df7 X-EPHeader: CA X-CMS-RootMailID: 20251121232820eucas1p13f5798a2d8c5049ae7cadc62cce63df7 References: <253c870f-770b-4102-be47-f8c06e9e6c31@samsung.com> <20251121232807.40491-1-21cnbao@gmail.com> On 22.11.2025 00:28, Barry Song wrote: > On Sat, Nov 22, 2025 at 12:09 AM Marek Szyprowski wrote: > [...] >> This version looks a bit better to me. Similar batching could be added >> also to dma_iova_link()/dma_iova_sync() paths. > Thanks, Marek. I will respin a new version. For dma_iova, I assume you meant > something like the following? > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c > index 7944a3af4545..7bb6ed663236 100644 > --- a/drivers/iommu/dma-iommu.c > +++ b/drivers/iommu/dma-iommu.c > @@ -1837,7 +1837,7 @@ static int __dma_iova_link(struct device *dev, dma_addr_t addr, > int prot = dma_info_to_prot(dir, coherent, attrs); > > if (!coherent && !(attrs & (DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_MMIO))) > - arch_sync_dma_for_device(phys, size, dir); > + arch_sync_dma_for_device_batch_add(phys, size, dir); > > return iommu_map_nosync(iommu_get_dma_domain(dev), addr, phys, size, > prot, GFP_ATOMIC); > @@ -1980,6 +1980,8 @@ int dma_iova_sync(struct device *dev, struct dma_iova_state *state, > dma_addr_t addr = state->addr + offset; > size_t iova_start_pad = iova_offset(iovad, addr); > > + if (!dev_is_dma_coherent(dev)) > + arch_sync_dma_batch_flush(); > return iommu_sync_map(domain, addr - iova_start_pad, > iova_align(iovad, size + iova_start_pad)); > } > > If so, I don't really have such hardware to test. I wonder if I can make it as > patch 6/6 when respinning, and still mark it as RFC v2. Or should I leave it as > is and expect someone with the hardware to test and send it? Yes, I meant something like the above diff, also for dma_iova_unlink(). It can be an additional, 6th patch with RFC tag, assuming You have no way to test it. Please notice that I've just sent a patch touching the similar code paths: https://lore.kernel.org/all/20251124170955.3884351-1-m.szyprowski@samsung.com/ Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland