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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E5370C3F2D1 for ; Wed, 4 Mar 2020 14:11:47 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id B99C220848 for ; Wed, 4 Mar 2020 14:11:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="TDi6iE5j" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B99C220848 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=lihdKOQ5xgyA872i7UkQoOFbzcsCEusraUirCJXg7U8=; b=TDi6iE5jfY+6AKeG69lAbaUGIO If6I+CaED02y0OzZlydplSyItpsVTLc9Gn4hzqgwa9iU25VMQx9+0sPLMWlP86QuDrnhYJ6IfPbVv uy2yXLte/1o9ljLU79hA3nNQo4u6Y0HOIkCfOkc5jgnLl4RF5PEJeJ5X0G/oVx+rGSgYiUhNNC8vy RKIuU2BV1hdHF8Hc1Z4rU5FveJakv27QIa/9CEw1o1MFZjWrkypStVqlpOU04LxZ47q0OuORMk9hT ipqIUI+/pD9KK1QzH99AQtL7iw2wskGIVxg0IzXqPpg7j/f7L+wGQo+x0pmzX5aI82kOS0dhs3NYf HgdK/zVQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1j9UkV-0008T3-BK; Wed, 04 Mar 2020 14:11:47 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1j9Ujp-0007jF-5a for linux-arm-kernel@lists.infradead.org; Wed, 04 Mar 2020 14:11:07 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 80A3A31B; Wed, 4 Mar 2020 06:11:04 -0800 (PST) Received: from p8cg001049571a15.arm.com (unknown [10.163.1.88]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 605C03F6CF; Wed, 4 Mar 2020 06:11:00 -0800 (PST) From: Anshuman Khandual To: linux-mm@kvack.org Subject: [PATCH V2 2/2] arm64/mm: Enable vmem_altmap support for vmemmap mappings Date: Wed, 4 Mar 2020 19:40:30 +0530 Message-Id: <1583331030-7335-3-git-send-email-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1583331030-7335-1-git-send-email-anshuman.khandual@arm.com> References: <1583331030-7335-1-git-send-email-anshuman.khandual@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200304_061105_342991_886C4A0E X-CRM114-Status: GOOD ( 16.80 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Yu Zhao , Anshuman Khandual , David Hildenbrand , Catalin Marinas , Steve Capper , linux-kernel@vger.kernel.org, Hsin-Yi Wang , Thomas Gleixner , Will Deacon , Andrew Morton , linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Device memory ranges when getting hot added into ZONE_DEVICE, might require their vmemmap mapping's backing memory to be allocated from their own range instead of consuming system memory. This prevents large system memory usage for potentially large device memory ranges. Device driver communicates this request via vmem_altmap structure. Architecture needs to take this request into account while creating and tearing down vemmmap mappings. This enables vmem_altmap support in vmemmap_populate() and vmemmap_free() which includes vmemmap_populate_basepages() used for ARM64_16K_PAGES and ARM64_64K_PAGES configs. Cc: Catalin Marinas Cc: Will Deacon Cc: Mark Rutland Cc: Steve Capper Cc: David Hildenbrand Cc: Yu Zhao Cc: Hsin-Yi Wang Cc: Thomas Gleixner Cc: Andrew Morton Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual --- arch/arm64/mm/mmu.c | 71 ++++++++++++++++++++++++++++++++------------- 1 file changed, 51 insertions(+), 20 deletions(-) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 27cb95c471eb..0e0a0ecc812e 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -727,15 +727,30 @@ int kern_addr_valid(unsigned long addr) } #ifdef CONFIG_MEMORY_HOTPLUG -static void free_hotplug_page_range(struct page *page, size_t size) +static void free_hotplug_page_range(struct page *page, size_t size, + struct vmem_altmap *altmap) { - WARN_ON(PageReserved(page)); - free_pages((unsigned long)page_address(page), get_order(size)); + if (altmap) { + /* + * Though unmap_hotplug_range() will tear down altmap based + * vmemmap mappings at all page table levels, these mappings + * should only have been created either at PTE or PMD level + * with vmemmap_populate_basepages() or vmemmap_populate() + * respectively. Unmapping requests at any other level will + * be problematic. Drop these warnings when vmemmap mapping + * is supported at PUD (even perhaps P4D) level. + */ + WARN_ON((size != PAGE_SIZE) && (size != PMD_SIZE)); + vmem_altmap_free(altmap, size >> PAGE_SHIFT); + } else { + WARN_ON(PageReserved(page)); + free_pages((unsigned long)page_address(page), get_order(size)); + } } static void free_hotplug_pgtable_page(struct page *page) { - free_hotplug_page_range(page, PAGE_SIZE); + free_hotplug_page_range(page, PAGE_SIZE, NULL); } static bool pgtable_range_aligned(unsigned long start, unsigned long end, @@ -758,7 +773,8 @@ static bool pgtable_range_aligned(unsigned long start, unsigned long end, } static void unmap_hotplug_pte_range(pmd_t *pmdp, unsigned long addr, - unsigned long end, bool free_mapped) + unsigned long end, bool free_mapped, + struct vmem_altmap *altmap) { pte_t *ptep, pte; @@ -772,12 +788,14 @@ static void unmap_hotplug_pte_range(pmd_t *pmdp, unsigned long addr, pte_clear(&init_mm, addr, ptep); flush_tlb_kernel_range(addr, addr + PAGE_SIZE); if (free_mapped) - free_hotplug_page_range(pte_page(pte), PAGE_SIZE); + free_hotplug_page_range(pte_page(pte), + PAGE_SIZE, altmap); } while (addr += PAGE_SIZE, addr < end); } static void unmap_hotplug_pmd_range(pud_t *pudp, unsigned long addr, - unsigned long end, bool free_mapped) + unsigned long end, bool free_mapped, + struct vmem_altmap *altmap) { unsigned long next; pmd_t *pmdp, pmd; @@ -800,16 +818,17 @@ static void unmap_hotplug_pmd_range(pud_t *pudp, unsigned long addr, flush_tlb_kernel_range(addr, addr + PAGE_SIZE); if (free_mapped) free_hotplug_page_range(pmd_page(pmd), - PMD_SIZE); + PMD_SIZE, altmap); continue; } WARN_ON(!pmd_table(pmd)); - unmap_hotplug_pte_range(pmdp, addr, next, free_mapped); + unmap_hotplug_pte_range(pmdp, addr, next, free_mapped, altmap); } while (addr = next, addr < end); } static void unmap_hotplug_pud_range(p4d_t *p4dp, unsigned long addr, - unsigned long end, bool free_mapped) + unsigned long end, bool free_mapped, + struct vmem_altmap *altmap) { unsigned long next; pud_t *pudp, pud; @@ -832,16 +851,17 @@ static void unmap_hotplug_pud_range(p4d_t *p4dp, unsigned long addr, flush_tlb_kernel_range(addr, addr + PAGE_SIZE); if (free_mapped) free_hotplug_page_range(pud_page(pud), - PUD_SIZE); + PUD_SIZE, altmap); continue; } WARN_ON(!pud_table(pud)); - unmap_hotplug_pmd_range(pudp, addr, next, free_mapped); + unmap_hotplug_pmd_range(pudp, addr, next, free_mapped, altmap); } while (addr = next, addr < end); } static void unmap_hotplug_p4d_range(pgd_t *pgdp, unsigned long addr, - unsigned long end, bool free_mapped) + unsigned long end, bool free_mapped, + struct vmem_altmap *altmap) { unsigned long next; p4d_t *p4dp, p4d; @@ -854,16 +874,24 @@ static void unmap_hotplug_p4d_range(pgd_t *pgdp, unsigned long addr, continue; WARN_ON(!p4d_present(p4d)); - unmap_hotplug_pud_range(p4dp, addr, next, free_mapped); + unmap_hotplug_pud_range(p4dp, addr, next, free_mapped, altmap); } while (addr = next, addr < end); } static void unmap_hotplug_range(unsigned long addr, unsigned long end, - bool free_mapped) + bool free_mapped, struct vmem_altmap *altmap) { unsigned long next; pgd_t *pgdp, pgd; + /* + * vmem_altmap can only be used as backing memory in a given + * page table mapping. In case backing memory itself is not + * being freed, then altmap is irrelevant. Warn about this + * inconsistency when encountered. + */ + WARN_ON(!free_mapped && altmap); + do { next = pgd_addr_end(addr, end); pgdp = pgd_offset_k(addr); @@ -872,7 +900,7 @@ static void unmap_hotplug_range(unsigned long addr, unsigned long end, continue; WARN_ON(!pgd_present(pgd)); - unmap_hotplug_p4d_range(pgdp, addr, next, free_mapped); + unmap_hotplug_p4d_range(pgdp, addr, next, free_mapped, altmap); } while (addr = next, addr < end); } @@ -1036,7 +1064,7 @@ static void free_empty_tables(unsigned long addr, unsigned long end, int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, struct vmem_altmap *altmap) { - return vmemmap_populate_basepages(start, end, node, NULL); + return vmemmap_populate_basepages(start, end, node, altmap); } #else /* !ARM64_SWAPPER_USES_SECTION_MAPS */ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, @@ -1063,7 +1091,10 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, if (pmd_none(READ_ONCE(*pmdp))) { void *p = NULL; - p = vmemmap_alloc_block_buf(PMD_SIZE, node); + if (altmap) + p = altmap_alloc_block_buf(PMD_SIZE, altmap); + else + p = vmemmap_alloc_block_buf(PMD_SIZE, node); if (!p) return -ENOMEM; @@ -1081,7 +1112,7 @@ void vmemmap_free(unsigned long start, unsigned long end, #ifdef CONFIG_MEMORY_HOTPLUG WARN_ON((start < VMEMMAP_START) || (end > VMEMMAP_END)); - unmap_hotplug_range(start, end, true); + unmap_hotplug_range(start, end, true, altmap); free_empty_tables(start, end, VMEMMAP_START, VMEMMAP_END); #endif } @@ -1369,7 +1400,7 @@ static void __remove_pgd_mapping(pgd_t *pgdir, unsigned long start, u64 size) WARN_ON(pgdir != init_mm.pgd); WARN_ON((start < PAGE_OFFSET) || (end > PAGE_END)); - unmap_hotplug_range(start, end, false); + unmap_hotplug_range(start, end, false, NULL); free_empty_tables(start, end, PAGE_OFFSET, PAGE_END); } -- 2.20.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel