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 7A12CD13561 for ; Sun, 27 Oct 2024 14:23:06 +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=tFfAVeRpTt9MOKvdbyKITP7haOM8Jd6d88FaRUe8ZOQ=; b=dj0wioF0FnGQ83yZn2s4ydLvsc lu+lkI1LK5dZRwBJ9sIicJVSJ7YIy/FavD/eQm66588H8B1kRvYEwwNg6kcQrRDgzJlZRflRZFOhs OI/GbakDffbvGgXpA9azceaKzOGJKLLAPaut6irnbxi3IX1WmlOePfZ58bVXpSQvZupKnplol8E7J +e1vnQTdIia6+xGUyHrvwdaxG6tfCR/0pdmBejuI8twlV4rY6hMGkIxS++wLVxjr0sPdJCjVCw83v 8gD/0Feq9NR1LOlYyXrmFjpByGIIWCtbrT05fi2yGQVER1jP7v9z44jR4ZLz8MK/fX0Jc/UZQ97gA FyEbyVEQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1t54AZ-00000008Kwv-0j14; Sun, 27 Oct 2024 14:23:03 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1t54AJ-00000008Kk0-3VQX for linux-nvme@bombadil.infradead.org; Sun, 27 Oct 2024 14:22:47 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Transfer-Encoding:MIME-Version :References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=tFfAVeRpTt9MOKvdbyKITP7haOM8Jd6d88FaRUe8ZOQ=; b=EsHkEmh4/Jowz+e2yKCYNUuUHs A8r7cqLRPdpLhgYlxyi91m7JXankxl99ErcQJ/QYNDccOe2bS7ywyVpDyiSCHLeZT5kFYvL+cIswC 4ZNMkyedSaSBKpgWUwsMwV1OX6X9uC2VZpI6NuzPC4UQSaKHdU9t1yHRYMZ8JQ0+synCaILV7Zr2d 6iXbR7kscreNwfc8NYNwhcRO4J/q4Onnxm5SSXpx/chz59+9zVN+BAHcdGktbW5EtO5Nj0P+ZY89+ Lunbadezk1ZF+SZroUWkFu9yv4x23iM5e4a9C3dq6P06tiGb6LSP04b9/cmpSL66DYVp5VEvsqyKE 1SKdUKnA==; Received: from nyc.source.kernel.org ([2604:1380:45d1:ec00::3]) by desiato.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1t54AD-00000009QLt-477e for linux-nvme@lists.infradead.org; Sun, 27 Oct 2024 14:22:46 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id C30C0A40F21; Sun, 27 Oct 2024 14:20:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CBBC4C4CEC3; Sun, 27 Oct 2024 14:22:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730038948; bh=LyGbooKE736rWckmyvuR6Y2aUxxUKiIhQ25bI43LeHo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iCkLbrpnlImhB9B2714xCMDVyAnzWG7MsfR2tObG6bSGDFDz4Bf4CI0mqKt+rhuYq oH9+qokY2xOMGvGOGy85p6vNn6z9dqDdwZ9MAzJ/Y7n8iQv0e0nn5FsdeSoMXGJcFj B+Zi8xW0UVh0uK/OidgiacDE2NCdMWAyryo2eQ61nfECpDk59aRsqWtCbWH4zdhzfH EE5mWIwZYs2U2XkGvGVAKEq7GkstM4Q+7cbJ824WG2VF+/8pl7vlytQS/XVuNbujES urNdKuuovQ1egFVlgv0jTDSmxVbzWG5blHyNDBWJJkFVst1jo9u8sMvdVfv9ThBNkJ kD4ta2u0CCROg== From: Leon Romanovsky To: Jens Axboe , Jason Gunthorpe , Robin Murphy , Joerg Roedel , Will Deacon , Christoph Hellwig , Sagi Grimberg Cc: Leon Romanovsky , Keith Busch , 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 , Jonathan Corbet , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-block@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: [PATCH 10/18] mm/hmm: let users to tag specific PFN with DMA mapped bit Date: Sun, 27 Oct 2024 16:21:10 +0200 Message-ID: <6c79710ccc5d9fec36172fea13498e30132a0600.1730037276.git.leon@kernel.org> X-Mailer: git-send-email 2.46.2 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-20241027_142244_748042_6DDBA569 X-CRM114-Status: GOOD ( 18.70 ) 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 | 14 ++++++++++++++ mm/hmm.c | 34 +++++++++++++++++++++------------- 2 files changed, 35 insertions(+), 13 deletions(-) diff --git a/include/linux/hmm.h b/include/linux/hmm.h index 126a36571667..5dd655f6766b 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 +38,10 @@ 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 flag, carried from Input to Output */ + HMM_PFN_DMA_MAPPED = 1UL << (BITS_PER_LONG - 7), + HMM_PFN_ORDER_SHIFT = (BITS_PER_LONG - 8), /* Input flags */ @@ -57,6 +63,14 @@ static inline struct page *hmm_pfn_to_page(unsigned long hmm_pfn) return pfn_to_page(hmm_pfn & ~HMM_PFN_FLAGS); } +/* + * hmm_pfn_to_phys() - return physical address pointed to by a device entry + */ +static inline phys_addr_t hmm_pfn_to_phys(unsigned long hmm_pfn) +{ + return __pfn_to_phys(hmm_pfn & ~HMM_PFN_FLAGS); +} + /* * hmm_pfn_to_map_order() - return the CPU mapping size order * diff --git a/mm/hmm.c b/mm/hmm.c index 7e0229ae4a5a..2a0c34d7cb2b 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; -- 2.46.2