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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 15E8CC43334 for ; Fri, 24 Jun 2022 17:39:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232579AbiFXRjU (ORCPT ); Fri, 24 Jun 2022 13:39:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36842 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232203AbiFXRh4 (ORCPT ); Fri, 24 Jun 2022 13:37:56 -0400 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0FEAC6DB37 for ; Fri, 24 Jun 2022 10:37:44 -0700 (PDT) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-2dc7bdd666fso26872577b3.7 for ; Fri, 24 Jun 2022 10:37:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=+v5vFcEkCeptJMisViVmMo9Bs1ZO+THs4heiTRIsd+o=; b=NNXX2wgNjzsnd7NQe74D6jQQ3JbhNS1xVYTChLiQX5nqdIcnMSKpyyj3i3EvpGCsEm RHq6youwXY0rUgRMsMTqDuY+7MTgv+Ntfb9USuGpLdovFk8QaUNnj/5hu4tOf0Mr8Ypa tM+TcTpJN5YH+/RNf30TRecLDgM5H/Zp5MJnxEVgf0YteupwUS+Lg1C1mvGu3kxmJaAP xgJKg9LuXjQrzoqn63vyXZqC4Ckt6dxdIBoGoTX+pIFxhc2k6bw9SxJVfy3KdgryLAmu 8iaVOe1LIhnXOC1SpxD4kIV9TfjqwXSaMv6b0r1/9KFQEay+2Tk+s5gsM4+trTfyjtP4 tSMw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=+v5vFcEkCeptJMisViVmMo9Bs1ZO+THs4heiTRIsd+o=; b=TlRMTihQpXKV8+Are596oJW0TjHT/rcUziUppx3KlB6cRADZZ219m5MDFl6qlZncJP q5QvFQF8AeYtgsG8I7BrhHpA/fkx+E9ST7v3v3dZRF7gVMOG31v2jBpSvwb3XaerCG3A cxeXGjQLWEiKdzYBXBWTCp5vtY3sjC3upr9jPZt3kCpOcBxl85CE4ZCgQiJoIw8wEbe6 DvSA4OZ6LqMPYJuj4m7vyvUOwHFybxuGf3ek63bYyRUk9ZoTxNoxU7sNnGADw973fy1i F/6upRw6KxBHRPTk5ft0lctaXPsU6UIR9VXS2xG/6k6jV9Ch3h5x85f8Vs5mbfYvk3fB LmmQ== X-Gm-Message-State: AJIora+36zAvojn7jCdX3mWozWckcaymCa4SiSVPzaNFCCQde7kG5Bzs 1datimYXiCUwbi+ZDfpvC2tlYuhvfNzmrYVK X-Google-Smtp-Source: AGRyM1uKY4yvxaVhU0NJgxRylqUzzNHeETpBTfmI2EV5YsAV33yJ/2TcaSldBOT8fH//yUIflu07auIqQ61eftvT X-Received: from jthoughton.c.googlers.com ([fda3:e722:ac3:cc00:14:4d90:c0a8:2a4f]) (user=jthoughton job=sendgmr) by 2002:a81:5e42:0:b0:31b:6254:1c2b with SMTP id s63-20020a815e42000000b0031b62541c2bmr3298ywb.35.1656092263238; Fri, 24 Jun 2022 10:37:43 -0700 (PDT) Date: Fri, 24 Jun 2022 17:36:54 +0000 In-Reply-To: <20220624173656.2033256-1-jthoughton@google.com> Message-Id: <20220624173656.2033256-25-jthoughton@google.com> Mime-Version: 1.0 References: <20220624173656.2033256-1-jthoughton@google.com> X-Mailer: git-send-email 2.37.0.rc0.161.g10f37bed90-goog Subject: [RFC PATCH 24/26] arm64/hugetlb: add support for high-granularity mappings From: James Houghton To: Mike Kravetz , Muchun Song , Peter Xu Cc: David Hildenbrand , David Rientjes , Axel Rasmussen , Mina Almasry , Jue Wang , Manish Mishra , "Dr . David Alan Gilbert" , linux-mm@kvack.org, linux-kernel@vger.kernel.org, James Houghton Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is included in this RFC to demonstrate how an architecture that doesn't use ARCH_WANT_GENERAL_HUGETLB can be updated to support HugeTLB high-granularity mappings: an architecture just needs to implement hugetlb_walk_to. Signed-off-by: James Houghton --- arch/arm64/Kconfig | 1 + arch/arm64/mm/hugetlbpage.c | 63 +++++++++++++++++++++++++++++++++++++ 2 files changed, 64 insertions(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 1652a9800ebe..74108713a99a 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -99,6 +99,7 @@ config ARM64 select ARCH_WANT_FRAME_POINTERS select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP + select ARCH_HAS_SPECIAL_HUGETLB_HGM select ARCH_WANT_LD_ORPHAN_WARN select ARCH_WANTS_NO_INSTR select ARCH_HAS_UBSAN_SANITIZE_ALL diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c index e2a5ec9fdc0d..1901818bed9d 100644 --- a/arch/arm64/mm/hugetlbpage.c +++ b/arch/arm64/mm/hugetlbpage.c @@ -281,6 +281,69 @@ void set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr, set_pte(ptep, pte); } +int hugetlb_walk_to(struct mm_struct *mm, struct hugetlb_pte *hpte, + unsigned long addr, unsigned long sz, bool stop_at_none) +{ + pgd_t *pgdp; + p4d_t *p4dp; + pte_t *ptep; + + if (!hpte->ptep) { + pgdp = pgd_offset(mm, addr); + p4dp = p4d_offset(pgdp, addr); + if (!p4dp) + return -ENOMEM; + hugetlb_pte_populate(hpte, (pte_t *)p4dp, P4D_SHIFT); + } + + while (hugetlb_pte_size(hpte) > sz && + !hugetlb_pte_present_leaf(hpte) && + !(stop_at_none && hugetlb_pte_none(hpte))) { + if (hpte->shift == PMD_SHIFT) { + unsigned long rounded_addr = sz == CONT_PTE_SIZE + ? addr & CONT_PTE_MASK + : addr; + + ptep = pte_offset_kernel((pmd_t *)hpte->ptep, + rounded_addr); + if (!ptep) + return -ENOMEM; + if (sz == CONT_PTE_SIZE) + hpte->shift = CONT_PTE_SHIFT; + else + hpte->shift = pte_cont(*ptep) ? CONT_PTE_SHIFT + : PAGE_SHIFT; + hpte->ptep = ptep; + } else if (hpte->shift == PUD_SHIFT) { + pud_t *pudp = (pud_t *)hpte->ptep; + + ptep = (pte_t *)pmd_alloc(mm, pudp, addr); + + if (!ptep) + return -ENOMEM; + if (sz == CONT_PMD_SIZE) + hpte->shift = CONT_PMD_SHIFT; + else + hpte->shift = pte_cont(*ptep) ? CONT_PMD_SHIFT + : PMD_SHIFT; + hpte->ptep = ptep; + } else if (hpte->shift == P4D_SHIFT) { + ptep = (pte_t *)pud_alloc(mm, (p4d_t *)hpte->ptep, addr); + if (!ptep) + return -ENOMEM; + hpte->shift = PUD_SHIFT; + hpte->ptep = ptep; + } else + /* + * This also catches the cases of CONT_PMD_SHIFT and + * CONT_PTE_SHIFT. Those PTEs should always be leaves. + */ + BUG(); + } + + return 0; +} + pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, unsigned long sz) { -- 2.37.0.rc0.161.g10f37bed90-goog