From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from ale.deltatee.com (ale.deltatee.com [204.191.154.188]) (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 727E731A549; Thu, 2 Jul 2026 15:46:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=204.191.154.188 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783007207; cv=none; b=IzZ8E4zYMeL1Rt/V0BYOy62xbjl4pOM3OlHaCCjFVwXUBrvVGn7kaT6SRmc1qhPibDWQJGO049kzEqAtQgHUlOUsMnoBMqv1WDZUr/RvuinSqL5bIfHA2jtE9i4hcsswmCpf0ub5e+eADQDPcRrku2MazUBwxXU9NGegMc9aue4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783007207; c=relaxed/simple; bh=BpqZXQ7tSLN0BXpsRqxL1k64attfyEvZ0QKJFK8v+XM=; h=Message-ID:Date:MIME-Version:To:Cc:References:From:In-Reply-To: Content-Type:Subject; b=hC/bQcj/Sax9EYAlN3dlx2Ma3YCD8B9+fVglM0S7JkN8wf9OWYw9KfU8XRfGgfPr8OgslX51SwVKyfQSdl6HinWIcj60Ua2/pSl3/ptGMb3p2A2Ai4Hoy/KM9esaj0xuSfpc+mxmTF69gjzvSV6qv7UM9LcQNJ9Og+R18EXCnhI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=deltatee.com; spf=pass smtp.mailfrom=deltatee.com; dkim=pass (2048-bit key) header.d=deltatee.com header.i=@deltatee.com header.b=NMJlC0W9; arc=none smtp.client-ip=204.191.154.188 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=deltatee.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=deltatee.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=deltatee.com header.i=@deltatee.com header.b="NMJlC0W9" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=deltatee.com; s=20200525; h=Subject:In-Reply-To:From:References:Cc:To: MIME-Version:Date:Message-ID:content-disposition; bh=kyJzbfSqoUXaNBv1Ig4SDg9TeDVODqylZdwHs0c6zpw=; b=NMJlC0W9kihForMdCYYnlLUQ6m Eo6IW7rO0b1c3osWSWCUUldacbvkYcIHJHIs657/dhe4oEXiTtpTQ/dWk3ifTTLUQaEbidde5h+Za PcycMOPmLVTwDWHJQDPiDcGfQFjTrxGqlbaAn1kK1DM5rhbiznK9fasb+RfVbru6MJxXbEPCEc2BB ISWRcrKmHu4YocW7NLlTKBCzF8RiOcqDAlrl1qmazF+AWcg8m31/uJD0FplDbG195cflmPyzGuwqL 1GZfpCJbvEWPB56K9HdzIMLEdCpT6Q5vbDcy9K/PQB2P0uo3+xF6t8DCMd8+dsioqd8R68fxzYcGo 8krZuUbA==; Received: from s0106ac1f6bb1ecac.cg.shawcable.net ([96.51.150.74] helo=[10.0.33.8]) by ale.deltatee.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.98.2) (envelope-from ) id 1wfJcc-00000006yLj-3jeO; Thu, 02 Jul 2026 09:46:39 -0600 Message-ID: <26f74cf0-8892-4672-b0e1-1f1a385c42bb@deltatee.com> Date: Thu, 2 Jul 2026 09:45:38 -0600 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird To: Matt Evans , Alex Williamson , Leon Romanovsky , Jason Gunthorpe , Alex Mastro , =?UTF-8?Q?Christian_K=C3=B6nig?= , Bjorn Helgaas , Kevin Tian , Pranjal Shrivastava Cc: Mahmoud Adam , David Matlack , =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= , Sumit Semwal , Ankit Agrawal , Alistair Popple , Vivek Kasireddy , linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, kvm@vger.kernel.org, linux-pci@vger.kernel.org References: <20260701171245.90111-1-matt@ozlabs.org> <20260701171245.90111-3-matt@ozlabs.org> Content-Language: en-CA From: Logan Gunthorpe In-Reply-To: <20260701171245.90111-3-matt@ozlabs.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 96.51.150.74 X-SA-Exim-Rcpt-To: matt@ozlabs.org, alex@shazbot.org, leon@kernel.org, jgg@nvidia.com, amastro@fb.com, christian.koenig@amd.com, bhelgaas@google.com, kevin.tian@intel.com, praan@google.com, mngyadam@amazon.de, dmatlack@google.com, bjorn@kernel.org, sumit.semwal@linaro.org, ankita@nvidia.com, apopple@nvidia.com, vivek.kasireddy@intel.com, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, kvm@vger.kernel.org, linux-pci@vger.kernel.org X-SA-Exim-Mail-From: logang@deltatee.com X-Spam-Level: Subject: Re: [PATCH v4 02/10] PCI/P2PDMA: Add CONFIG_PCI_P2PDMA_CORE X-SA-Exim-Version: 4.2.1 (built Sun, 23 Feb 2025 07:57:16 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) On 2026-07-01 11:12 a.m., Matt Evans wrote:> > PCI POWER CONTROL > diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig > index 33c88432b728..59d70bc84cc9 100644 > --- a/drivers/pci/Kconfig > +++ b/drivers/pci/Kconfig > @@ -206,11 +206,7 @@ config PCIE_TPH > config PCI_P2PDMA > bool "PCI peer-to-peer transfer support" > depends on ZONE_DEVICE > - # > - # The need for the scatterlist DMA bus address flag means PCI P2PDMA > - # requires 64bit > - # > - depends on 64BIT > + select PCI_P2PDMA_CORE Can we remove this dependency on 64BIT? Althogh it looks like af2880ec440 complicated the issue a bit. If I remember correctly, the original reason for this is because on 64bit systems dma_flags fit into unusued space in struct scatterlist and on 32bit systems this space didn't exist and thus adding the flag required increasing the size of the structure which wasn't desirable at the time. But af2880ec440 introduced CONFIG_NEED_SG_DMA_FLAGS which doesn't depend on 64bit which means if CONFIG_IOMMU_DMA and CONFIG_SWIOTLB are now set on 32bit systems that structure will grow quite a bit. So maybe at this point it's fine to enable this on 32bit systems and we can remove this requirement. However, I think we should do that explicitly in its own patch, not hide it in this refactoring patch. Logan