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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B201CCA0FED for ; Tue, 9 Sep 2025 13:29:50 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4cLl5w3bjXz3d2N; Tue, 9 Sep 2025 23:29:08 +1000 (AEST) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip="2600:3c04:e001:324:0:1991:8:25" ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1757424548; cv=none; b=NXwd/ek0qpw4gZNij0fTXH3ZIT+mrsIVfRsYSNYJLruZMSzcbuEA+wfQg5P01b3LQGJeF7W0AfvX8q0CMv20GKP9HoHMU2wQM9lu3zBOPa/y5aiSLjOLvfyuUqaI9sJNKraFP2GDlUx1Rfx1xLG8RBUjFGp7XaKZJFKsILIsQpRaUicKD+/hmRJC5ZdS0b5zar9kzEmI/6uLA+Qz4/w5FALf02rV5I5Z4TRffiBaZ9L/s/8bGy9Lwe8aMJTItG/l7gY38J0M8QuC4YRhet0zloWyAHKK+PeNR/5wo+5eZ/uBQwxojJPybw+VS4OF6HOEl+78LWFD+v5NwWA6l9jXcQ== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1757424548; c=relaxed/relaxed; bh=hT6tMxxj7QGpFRMwj1+ZfG20o1qByFSHIC0k6CdAwac=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=nqr4J39OTUKRR1psAIjsxfkuu8jS+X1nDX4g4FLX1S9zn09fxFoj9AYfR7QMd4Zb3J/Hk/E4RQy/k3D1Kvgx3XaSThw36os/LE7Ioy3VwIgOSQFt1nYIu1VgkcHek+MMoJDAc2Lzp34QFkzQM/kGsAqV9tg9QXnIcHByfQusk1ayCCYIHj47B4dxVppfM6lt6zBdFj1GVBwtDBTc2smXa2J1tFXR1LeIvNys1Ino1aiOB4dGg9V46Dj9MJB/VIT7kU+IRO5ynZRSl2RGgDaldWQZd0znSdCarfNZi8gPzaQ2nYtN3t3kX16VuZfM1SpNHTkApqWO46PhlXv9qiMFPw== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=kernel.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=tnTViotB; dkim-atps=neutral; spf=pass (client-ip=2600:3c04:e001:324:0:1991:8:25; helo=tor.source.kernel.org; envelope-from=leon@kernel.org; receiver=lists.ozlabs.org) smtp.mailfrom=kernel.org Authentication-Results: lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=kernel.org Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=tnTViotB; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=2600:3c04:e001:324:0:1991:8:25; helo=tor.source.kernel.org; envelope-from=leon@kernel.org; receiver=lists.ozlabs.org) Received: from tor.source.kernel.org (tor.source.kernel.org [IPv6:2600:3c04:e001:324:0:1991:8:25]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4cLl5v53Qyz3cyL for ; Tue, 9 Sep 2025 23:29:07 +1000 (AEST) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id D79DA601AB; Tue, 9 Sep 2025 13:29:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EE671C4CEF4; Tue, 9 Sep 2025 13:29:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1757424545; bh=ThC+GnSzG3vqrBq8iTzTPlcPa91tU2BQkMRg6ndRAuA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tnTViotBzgzX8VJMiUdP1iBUBwTcHGl4cXP5/xMCQJd3NuJ+v83PZRp+IV4I6m6Oo rii0+a9xxI6kUod6ywO0FDmoTZ6nHn1Sm9TRhAhDLtUAwTh72wrfQLc04U7MeCpJP7 S+VB1HVBG2J4AB5r/4HEc/HDCNwV9/HfLsWB9aqhPOk5wvZ5OXodZEfSrk5TQI0YSe 2rgbYngdJVyQWuu3KtxqmyHFWhVGXg7iRlR+oGtwNzAeTNGHstyq5kW2vRrVG1sC4O sQLrmM3sgvgI/IElfjSWQ/akyQs02UZyEB+0KaMdypAsViiUDxdz4nCkmXQU4JWJEG mVUoTlUsHhrUw== From: Leon Romanovsky To: Marek Szyprowski Cc: Leon Romanovsky , Jason Gunthorpe , Abdiel Janulgue , Alexander Potapenko , Alex Gaynor , Andrew Morton , Christoph Hellwig , Danilo Krummrich , David Hildenbrand , iommu@lists.linux.dev, Jason Wang , Jens Axboe , Joerg Roedel , Jonathan Corbet , Juergen Gross , kasan-dev@googlegroups.com, Keith Busch , linux-block@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-nvme@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-trace-kernel@vger.kernel.org, Madhavan Srinivasan , Masami Hiramatsu , Michael Ellerman , "Michael S. Tsirkin" , Miguel Ojeda , Robin Murphy , rust-for-linux@vger.kernel.org, Sagi Grimberg , Stefano Stabellini , Steven Rostedt , virtualization@lists.linux.dev, Will Deacon , xen-devel@lists.xenproject.org Subject: [PATCH v6 13/16] mm/hmm: properly take MMIO path Date: Tue, 9 Sep 2025 16:27:41 +0300 Message-ID: <998251caf3f9d1a3f6f8205f1f494c707fb4d8fa.1757423202.git.leonro@nvidia.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: References: X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Leon Romanovsky In case peer-to-peer transaction traverses through host bridge, the IOMMU needs to have IOMMU_MMIO flag, together with skip of CPU sync. The latter was handled by provided DMA_ATTR_SKIP_CPU_SYNC flag, but IOMMU flag was missed, due to assumption that such memory can be treated as regular one. Reuse newly introduced DMA attribute to properly take MMIO path. Reviewed-by: Jason Gunthorpe Signed-off-by: Leon Romanovsky --- mm/hmm.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/mm/hmm.c b/mm/hmm.c index 015ab243f0813..6556c0e074ba8 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -746,7 +746,7 @@ dma_addr_t hmm_dma_map_pfn(struct device *dev, struct hmm_dma_map *map, case PCI_P2PDMA_MAP_NONE: break; case PCI_P2PDMA_MAP_THRU_HOST_BRIDGE: - attrs |= DMA_ATTR_SKIP_CPU_SYNC; + attrs |= DMA_ATTR_MMIO; pfns[idx] |= HMM_PFN_P2PDMA; break; case PCI_P2PDMA_MAP_BUS_ADDR: @@ -776,7 +776,7 @@ dma_addr_t hmm_dma_map_pfn(struct device *dev, struct hmm_dma_map *map, goto error; dma_addr = dma_map_phys(dev, paddr, map->dma_entry_size, - DMA_BIDIRECTIONAL, 0); + DMA_BIDIRECTIONAL, attrs); if (dma_mapping_error(dev, dma_addr)) goto error; @@ -811,16 +811,17 @@ bool hmm_dma_unmap_pfn(struct device *dev, struct hmm_dma_map *map, size_t idx) if ((pfns[idx] & valid_dma) != valid_dma) return false; + if (pfns[idx] & HMM_PFN_P2PDMA) + attrs |= DMA_ATTR_MMIO; + if (pfns[idx] & HMM_PFN_P2PDMA_BUS) ; /* no need to unmap bus address P2P mappings */ - else if (dma_use_iova(state)) { - if (pfns[idx] & HMM_PFN_P2PDMA) - attrs |= DMA_ATTR_SKIP_CPU_SYNC; + else if (dma_use_iova(state)) dma_iova_unlink(dev, state, idx * map->dma_entry_size, map->dma_entry_size, DMA_BIDIRECTIONAL, attrs); - } else if (dma_need_unmap(dev)) + else if (dma_need_unmap(dev)) dma_unmap_phys(dev, dma_addrs[idx], map->dma_entry_size, - DMA_BIDIRECTIONAL, 0); + DMA_BIDIRECTIONAL, attrs); pfns[idx] &= ~(HMM_PFN_DMA_MAPPED | HMM_PFN_P2PDMA | HMM_PFN_P2PDMA_BUS); -- 2.51.0