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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 A86D0C41513 for ; Tue, 2 Jul 2024 09:10:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=9l3RqBQ3wmhiS4Devu11UR9cNpL8lZMERvC1jOBPYeU=; b=Oki1DFvOovvLdk5tEj3d9uHwkh QywUCbzH6gYk/dCGowCG1JMbPRM4yzgzEwqvUTbVTpNnXWL8TwmaHjAm9VVUwwHRHhhz01cQvi0Qt w/cq9blU/oaRInTCTaI+tIar9GrdHv5lU/sFS2xyK4vxVYKkujz2tQeOtyZf55whVnamr+HxiZ8zW x1ykwzmMn7UKjnw7DV4cpllRvR/0B46PApem7Eg8UTHHgLO62sT+q6XiUgOxNv6Pufq9G1t+uelEH ZWaKddoN0jfDZ0+9kc2YGv53oPweqsyXIIsLY3iUKUMXrCojxCg+oR+D2k0r+eQbyx+7g8f2SC1ZR pWGnHdig==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sOZWp-000000065MM-0WFq; Tue, 02 Jul 2024 09:10:23 +0000 Received: from sin.source.kernel.org ([2604:1380:40e1:4800::1]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sOZWl-000000065Ic-0rQM for linux-nvme@lists.infradead.org; Tue, 02 Jul 2024 09:10:21 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sin.source.kernel.org (Postfix) with ESMTP id 1FC19CE1CF5; Tue, 2 Jul 2024 09:10:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E8E09C4AF0E; Tue, 2 Jul 2024 09:10:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1719911416; bh=r8LbBOjlbH4F69KVmFsNaHjJ/rODIFYYIWRpcAsJOVI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DERWykstv7XxGRlK5d+9zV0EQM0MK52hTvvioFtFjlLgY6y7WByKUa78ayxSb4kv4 I+xUVII03CJetjfBvTMv9CMMhQJfzVzLz89kaGypwXqqSFHhbw4Gb2EbFJGDnfX17l 0aC4Byhh+gWLSP7xqntoErbx/0yPnHiKuF5CB/Xs9/iSM9GN7ebAkO6YOTDfK+Sr8y dJtkIzyXzi0gzX+IoPLVGBHI3F2b9pwZ+KO31UXjhbL9I3Iuq75SeGIsrKaVl1FT3q sHBmNAh3u7+dpLJB9+kZkDVxWvxbuHf4tfrlHP2fR8bQCt2MPqKJJkSIF05sdFYODC r+/wFzkIKdacg== From: Leon Romanovsky To: Jens Axboe , Jason Gunthorpe , Robin Murphy , Joerg Roedel , Will Deacon , Keith Busch , Christoph Hellwig , "Zeng, Oak" , Chaitanya Kulkarni Cc: Leon Romanovsky , Sagi Grimberg , Bjorn Helgaas , Logan Gunthorpe , Yishai Hadas , Shameer Kolothum , Kevin Tian , Alex Williamson , Marek Szyprowski , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Andrew Morton , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, iommu@lists.linux.dev, linux-nvme@lists.infradead.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org Subject: [RFC PATCH v1 05/18] mm/hmm: let users to tag specific PFN with DMA mapped bit Date: Tue, 2 Jul 2024 12:09:35 +0300 Message-ID: <769b6266d5e8638322f25550dd01a85515bf9d08.1719909395.git.leon@kernel.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240702_021019_652636_DF5F4593 X-CRM114-Status: GOOD ( 16.64 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org From: Leon Romanovsky Introduce new sticky flag (HMM_PFN_DMA_MAPPED), which isn't overwritten by HMM range fault. Such flag allows users to tag specific PFNs with information if this specific PFN was already DMA mapped. Signed-off-by: Leon Romanovsky --- include/linux/hmm.h | 4 ++++ mm/hmm.c | 34 +++++++++++++++++++++------------- 2 files changed, 25 insertions(+), 13 deletions(-) diff --git a/include/linux/hmm.h b/include/linux/hmm.h index 126a36571667..2999697db83a 100644 --- a/include/linux/hmm.h +++ b/include/linux/hmm.h @@ -23,6 +23,8 @@ struct mmu_interval_notifier; * HMM_PFN_WRITE - if the page memory can be written to (requires HMM_PFN_VALID) * HMM_PFN_ERROR - accessing the pfn is impossible and the device should * fail. ie poisoned memory, special pages, no vma, etc + * HMM_PFN_DMA_MAPPED - Flag preserved on input-to-output transformation + * to mark that page is already DMA mapped * * On input: * 0 - Return the current state of the page, do not fault it. @@ -36,6 +38,8 @@ enum hmm_pfn_flags { HMM_PFN_VALID = 1UL << (BITS_PER_LONG - 1), HMM_PFN_WRITE = 1UL << (BITS_PER_LONG - 2), HMM_PFN_ERROR = 1UL << (BITS_PER_LONG - 3), + /* Sticky lag, carried from Input to Output */ + HMM_PFN_DMA_MAPPED = 1UL << (BITS_PER_LONG - 7), HMM_PFN_ORDER_SHIFT = (BITS_PER_LONG - 8), /* Input flags */ diff --git a/mm/hmm.c b/mm/hmm.c index 93aebd9cc130..03aeb9929d9e 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -44,8 +44,10 @@ static int hmm_pfns_fill(unsigned long addr, unsigned long end, { unsigned long i = (addr - range->start) >> PAGE_SHIFT; - for (; addr < end; addr += PAGE_SIZE, i++) - range->hmm_pfns[i] = cpu_flags; + for (; addr < end; addr += PAGE_SIZE, i++) { + range->hmm_pfns[i] &= HMM_PFN_DMA_MAPPED; + range->hmm_pfns[i] |= cpu_flags; + } return 0; } @@ -202,8 +204,10 @@ static int hmm_vma_handle_pmd(struct mm_walk *walk, unsigned long addr, return hmm_vma_fault(addr, end, required_fault, walk); pfn = pmd_pfn(pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT); - for (i = 0; addr < end; addr += PAGE_SIZE, i++, pfn++) - hmm_pfns[i] = pfn | cpu_flags; + for (i = 0; addr < end; addr += PAGE_SIZE, i++, pfn++) { + hmm_pfns[i] &= HMM_PFN_DMA_MAPPED; + hmm_pfns[i] |= pfn | cpu_flags; + } return 0; } #else /* CONFIG_TRANSPARENT_HUGEPAGE */ @@ -236,7 +240,7 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, hmm_pte_need_fault(hmm_vma_walk, pfn_req_flags, 0); if (required_fault) goto fault; - *hmm_pfn = 0; + *hmm_pfn = *hmm_pfn & HMM_PFN_DMA_MAPPED; return 0; } @@ -253,14 +257,14 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, cpu_flags = HMM_PFN_VALID; if (is_writable_device_private_entry(entry)) cpu_flags |= HMM_PFN_WRITE; - *hmm_pfn = swp_offset_pfn(entry) | cpu_flags; + *hmm_pfn = (*hmm_pfn & HMM_PFN_DMA_MAPPED) | swp_offset_pfn(entry) | cpu_flags; return 0; } required_fault = hmm_pte_need_fault(hmm_vma_walk, pfn_req_flags, 0); if (!required_fault) { - *hmm_pfn = 0; + *hmm_pfn = *hmm_pfn & HMM_PFN_DMA_MAPPED; return 0; } @@ -304,11 +308,11 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, pte_unmap(ptep); return -EFAULT; } - *hmm_pfn = HMM_PFN_ERROR; + *hmm_pfn = (*hmm_pfn & HMM_PFN_DMA_MAPPED) | HMM_PFN_ERROR; return 0; } - *hmm_pfn = pte_pfn(pte) | cpu_flags; + *hmm_pfn = (*hmm_pfn & HMM_PFN_DMA_MAPPED) | pte_pfn(pte) | cpu_flags; return 0; fault: @@ -448,8 +452,10 @@ static int hmm_vma_walk_pud(pud_t *pudp, unsigned long start, unsigned long end, } pfn = pud_pfn(pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT); - for (i = 0; i < npages; ++i, ++pfn) - hmm_pfns[i] = pfn | cpu_flags; + for (i = 0; i < npages; ++i, ++pfn) { + hmm_pfns[i] &= HMM_PFN_DMA_MAPPED; + hmm_pfns[i] |= pfn | cpu_flags; + } goto out_unlock; } @@ -507,8 +513,10 @@ static int hmm_vma_walk_hugetlb_entry(pte_t *pte, unsigned long hmask, } pfn = pte_pfn(entry) + ((start & ~hmask) >> PAGE_SHIFT); - for (; addr < end; addr += PAGE_SIZE, i++, pfn++) - range->hmm_pfns[i] = pfn | cpu_flags; + for (; addr < end; addr += PAGE_SIZE, i++, pfn++) { + range->hmm_pfns[i] &= HMM_PFN_DMA_MAPPED; + range->hmm_pfns[i] |= pfn | cpu_flags; + } spin_unlock(ptl); return 0; -- 2.45.2