From patchwork Mon Nov 30 11:27:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Zijlstra X-Patchwork-Id: 11940247 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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 2E5BCC64E90 for ; Mon, 30 Nov 2020 11:38:28 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8D16A20870 for ; Mon, 30 Nov 2020 11:38:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="nVErVX4k" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8D16A20870 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4C7608D0006; Mon, 30 Nov 2020 06:38:25 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 4866C8D0005; Mon, 30 Nov 2020 06:38:25 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 33D688D0005; Mon, 30 Nov 2020 06:38:25 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0190.hostedemail.com [216.40.44.190]) by kanga.kvack.org (Postfix) with ESMTP id 1CAEB8D0001 for ; Mon, 30 Nov 2020 06:38:25 -0500 (EST) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id DD6283634 for ; Mon, 30 Nov 2020 11:38:24 +0000 (UTC) X-FDA: 77540886528.25.fight19_251476a273a1 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin25.hostedemail.com (Postfix) with ESMTP id B984F1804E3BC for ; Mon, 30 Nov 2020 11:38:24 +0000 (UTC) X-HE-Tag: fight19_251476a273a1 X-Filterd-Recvd-Size: 5847 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf06.hostedemail.com (Postfix) with ESMTP for ; Mon, 30 Nov 2020 11:38:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=f4g92HolWEIcUN5sHQre4J13ebXNQzotEK5t5/pJgYg=; b=nVErVX4kx+o9OjH/bg2ppeww7q wtGoAs11AZd7qKjpkmAcJ3C4Ay0JfPzveCcIRguanHrKAAJM+oiSfvTwmS46L6fh70lCf4g27qUy/ PN5zperMQcjygmWj2pRcD91mVsCuOhq/Q0vWeMCxFipB+m4kXm2qzmiT+/SoUn7oU0pLHGQA1qx2j UF7W0KA9QvPnznSF6TvhEgq6gAZXa6xPqcC7GYdNbiJDy+DSHMzvBfnZJlrYIkiCQxLD3eI11sBe0 AydvPyfKm50jvfvJtGL8aWLNz6yXsNv1nytu7gf0ocWanej63lgwXkNL+tYUAsnggi/ArjsB0U/oP PV8CLKeQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kjhVa-0007Qd-Rm; Mon, 30 Nov 2020 11:38:19 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id E68FC30477A; Mon, 30 Nov 2020 12:38:17 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id D4FE02B84F9C4; Mon, 30 Nov 2020 12:38:17 +0100 (CET) Message-ID: <20201130113602.900215647@infradead.org> User-Agent: quilt/0.66 Date: Mon, 30 Nov 2020 12:27:07 +0100 From: Peter Zijlstra To: x86@kernel.org, willy@infradead.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, aarcange@redhat.com, kirill.shutemov@linux.intel.com, jroedel@suse.de, peterz@infradead.org Subject: [RFC][PATCH 2/9] x86/mm/pae: Make pmd_t similar to pte_t References: <20201130112705.900705277@infradead.org> MIME-Version: 1.0 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: Instead of mucking about with at least 2 different ways of fudging it, do the same thing we do for pte_t. Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/include/asm/pgtable-3level.h | 42 +++++++++------------------- arch/x86/include/asm/pgtable-3level_types.h | 7 ++++ arch/x86/include/asm/pgtable_64_types.h | 1 arch/x86/include/asm/pgtable_types.h | 4 -- 4 files changed, 23 insertions(+), 31 deletions(-) --- a/arch/x86/include/asm/pgtable-3level.h +++ b/arch/x86/include/asm/pgtable-3level.h @@ -87,7 +87,7 @@ static inline pmd_t pmd_read_atomic(pmd_ ret |= ((pmdval_t)*(tmp + 1)) << 32; } - return (pmd_t) { ret }; + return (pmd_t) { .pmd = ret }; } static inline void native_set_pte_atomic(pte_t *ptep, pte_t pte) @@ -121,12 +121,11 @@ static inline void native_pte_clear(stru ptep->pte_high = 0; } -static inline void native_pmd_clear(pmd_t *pmd) +static inline void native_pmd_clear(pmd_t *pmdp) { - u32 *tmp = (u32 *)pmd; - *tmp = 0; + pmdp->pmd_low = 0; smp_wmb(); - *(tmp + 1) = 0; + pmdp->pmd_high = 0; } static inline void native_pud_clear(pud_t *pudp) @@ -162,25 +161,17 @@ static inline pte_t native_ptep_get_and_ #define native_ptep_get_and_clear(xp) native_local_ptep_get_and_clear(xp) #endif -union split_pmd { - struct { - u32 pmd_low; - u32 pmd_high; - }; - pmd_t pmd; -}; - #ifdef CONFIG_SMP static inline pmd_t native_pmdp_get_and_clear(pmd_t *pmdp) { - union split_pmd res, *orig = (union split_pmd *)pmdp; + pmd_t res; /* xchg acts as a barrier before setting of the high bits */ - res.pmd_low = xchg(&orig->pmd_low, 0); - res.pmd_high = orig->pmd_high; - orig->pmd_high = 0; + res.pmd_low = xchg(&pmdp->pmd_low, 0); + res.pmd_high = READ_ONCE(pmdp->pmd_high); + WRITE_ONCE(pmdp->pmd_high, 0); - return res.pmd; + return res; } #else #define native_pmdp_get_and_clear(xp) native_local_pmdp_get_and_clear(xp) @@ -199,17 +190,12 @@ static inline pmd_t pmdp_establish(struc * anybody. */ if (!(pmd_val(pmd) & _PAGE_PRESENT)) { - union split_pmd old, new, *ptr; - - ptr = (union split_pmd *)pmdp; - - new.pmd = pmd; - /* xchg acts as a barrier before setting of the high bits */ - old.pmd_low = xchg(&ptr->pmd_low, new.pmd_low); - old.pmd_high = ptr->pmd_high; - ptr->pmd_high = new.pmd_high; - return old.pmd; + old.pmd_low = xchg(&pmdp->pmd_low, pmd.pmd_low); + old.pmd_high = READ_ONCE(pmdp->pmd_high); + WRITE_ONCE(pmdp->pmd_high, pmd.pmd_high); + + return old; } do { --- a/arch/x86/include/asm/pgtable-3level_types.h +++ b/arch/x86/include/asm/pgtable-3level_types.h @@ -18,6 +18,13 @@ typedef union { }; pteval_t pte; } pte_t; + +typedef union { + struct { + unsigned long pmd_low, pmd_high; + }; + pmdval_t pmd; +} pmd_t; #endif /* !__ASSEMBLY__ */ #define SHARED_KERNEL_PMD (!static_cpu_has(X86_FEATURE_PTI)) --- a/arch/x86/include/asm/pgtable_64_types.h +++ b/arch/x86/include/asm/pgtable_64_types.h @@ -19,6 +19,7 @@ typedef unsigned long pgdval_t; typedef unsigned long pgprotval_t; typedef struct { pteval_t pte; } pte_t; +typedef struct { pmdval_t pmd; } pmd_t; #ifdef CONFIG_X86_5LEVEL extern unsigned int __pgtable_l5_enabled; --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -381,11 +381,9 @@ static inline pudval_t native_pud_val(pu #endif #if CONFIG_PGTABLE_LEVELS > 2 -typedef struct { pmdval_t pmd; } pmd_t; - static inline pmd_t native_make_pmd(pmdval_t val) { - return (pmd_t) { val }; + return (pmd_t) { .pmd = val }; } static inline pmdval_t native_pmd_val(pmd_t pmd)