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Wed, 6 Nov 2024 11:50:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730893831; bh=QdMPZHgJrfGoDCyj4CISAO6jV7whENAAUWugSV2GSyc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=X3xjIyhq24iZe673vRAZfOBIaMxw63aj0oCZiuMf+cMUfa3KEwuHxFv10lfPd+LXi cX8RndroDQo8mAxGlNrQKsBGrT+Tn9ncvrOczGH1fOzbfcWtZcz+o2ZklicpXkljhj CR82ei9oaYq+EpM67T4Z+pAyawHDus2fFTo2JuJ7x8RwEPpyDe7fV1lwuc6pJ2z+g0 HJ6UKOajq0zu26WNinUjCfUaFl6njx0GBNaIjRVIK3YxTAorE/KaH86NTMRdt+YlWx 7dFq5n/713WK7CpEXfxiWlqOnT4MY3HeWkL8TPFNWYmD8uRdS258NMiVMn0h0Sqz/d Yx8czOHfsUw5A== 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?b?SsOpcsO0bWUgR2xpc3Nl?= , 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, Randy Dunlap Subject: [PATCH v2 10/17] mm/hmm: let users to tag specific PFN with DMA mapped bit Date: Wed, 6 Nov 2024 15:49:38 +0200 Message-ID: X-Mailer: git-send-email 2.47.0 In-Reply-To: References: MIME-Version: 1.0 X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 96202A0040 X-Stat-Signature: ectsmudk6r1k5fjorpnsorweumfgcxmo X-Rspam-User: X-HE-Tag: 1730893797-402316 X-HE-Meta: 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 Rk2zFou3 UvhpYdlQXYPAstOB0cM+PkPE+6FkYI7K5LdFh9aNZWm1o8WY38SLxBoRZJ3x8TfQCSOH5lJwhyFElIUJmbl9mDGA6+r5KiLDlyCu1fAijNR/K0zdPA9Sv+bkvYb+KhCieQvd364FdCCAdzCykMXBmS53A82y0sFRV7/tSNvVsN2sx3J6wkbJz7MzhwnZavzsVcRIPZU8WGNBylJMfVk9tnm9Ic2ORPxs9hKYKkEjVMs+lWCU2ZjNTKSfN3UkhMFyocDkF8wQY18zxzjsz8V783D66hkQGj8IIXHVY8kK/by/24T1H7GD7W9Od42xc3QdZ63bRRUQkuWoOCTEfjHoho+4dgWzrV7tJSdUM X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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;