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=-3.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 DD2FBC43381 for ; Tue, 19 Feb 2019 10:33:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A64512146E for ; Tue, 19 Feb 2019 10:33:47 +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="dFYG6VAK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728647AbfBSKdS (ORCPT ); Tue, 19 Feb 2019 05:33:18 -0500 Received: from merlin.infradead.org ([205.233.59.134]:55578 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728034AbfBSKdQ (ORCPT ); Tue, 19 Feb 2019 05:33:16 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-Id:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=1m499lCoWZDawBwduH5mia3SdJ+bH6wWKMriVQsCXbM=; b=dFYG6VAK1LK+4vkgXN0vUIsqq6 5fk4Ykx9noitYB0eJyqW1qO8Q7PGgAjnssomkzP9XeppAeiW2TEx0TrfM5DUMHDs1xdWzFGndumss PniHG02dFakkjoWJu6EbacmsGYQzXCHGEB6c4TTk33Da1gvaTUvQAIq2l+MiB2Z69fS6ceTTT8jDN 1AaBvXf0V+ZrjSUR7QrGlwOPBXx0t6bzYA+uUhrNnu0mTnDu3bNz9MWr643UYdj1T4Ux+2RqnDlJ9 goOlZiJE9FufW0cR0uBywsIk1rJhozVPoroSLqKLnkhutKAr4Nt7bBCTZ8rOqR/Q3yTc+OjFKP27U 4gfRfKdQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1gw2hn-0000di-I4; Tue, 19 Feb 2019 10:32:52 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 550AC285202C6; Tue, 19 Feb 2019 11:32:48 +0100 (CET) Message-Id: <20190219103233.148854086@infradead.org> User-Agent: quilt/0.65 Date: Tue, 19 Feb 2019 11:31:53 +0100 From: Peter Zijlstra To: will.deacon@arm.com, aneesh.kumar@linux.vnet.ibm.com, akpm@linux-foundation.org, npiggin@gmail.com Cc: linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, peterz@infradead.org, linux@armlinux.org.uk, heiko.carstens@de.ibm.com, riel@surriel.com Subject: [PATCH v6 05/18] asm-generic/tlb: Provide generic tlb_flush() based on flush_tlb_mm() References: <20190219103148.192029670@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When an architecture does not have (an efficient) flush_tlb_range(), but instead always uses full TLB invalidates, the current generic tlb_flush() is sub-optimal, for it will generate extra flushes in order to keep the range small. But if we cannot do range flushes, that is a moot concern. Optionally provide this simplified default. Signed-off-by: Peter Zijlstra (Intel) --- include/asm-generic/tlb.h | 41 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 40 insertions(+), 1 deletion(-) --- a/include/asm-generic/tlb.h +++ b/include/asm-generic/tlb.h @@ -114,7 +114,8 @@ * returns the smallest TLB entry size unmapped in this range. * * If an architecture does not provide tlb_flush() a default implementation - * based on flush_tlb_range() will be used. + * based on flush_tlb_range() will be used, unless MMU_GATHER_NO_RANGE is + * specified, in which case we'll default to flush_tlb_mm(). * * Additionally there are a few opt-in features: * @@ -140,6 +141,9 @@ * the page-table pages. Required if you use HAVE_RCU_TABLE_FREE and your * architecture uses the Linux page-tables natively. * + * MMU_GATHER_NO_RANGE + * + * Use this if your architecture lacks an efficient flush_tlb_range(). */ #define HAVE_GENERIC_MMU_GATHER @@ -302,12 +306,45 @@ static inline void __tlb_reset_range(str */ } +#ifdef CONFIG_MMU_GATHER_NO_RANGE + +#if defined(tlb_flush) || defined(tlb_start_vma) || defined(tlb_end_vma) +#error MMU_GATHER_NO_RANGE relies on default tlb_flush(), tlb_start_vma() and tlb_end_vma() +#endif + +/* + * When an architecture does not have efficient means of range flushing TLBs + * there is no point in doing intermediate flushes on tlb_end_vma() to keep the + * range small. We equally don't have to worry about page granularity or other + * things. + * + * All we need to do is issue a full flush for any !0 range. + */ +static inline void tlb_flush(struct mmu_gather *tlb) +{ + if (tlb->end) + flush_tlb_mm(tlb->mm); +} + +static inline void +tlb_update_vma_flags(struct mmu_gather *tlb, struct vm_area_struct *vma) { } + +#define tlb_end_vma tlb_end_vma +static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma) { } + +#else /* CONFIG_MMU_GATHER_NO_RANGE */ + #ifndef tlb_flush #if defined(tlb_start_vma) || defined(tlb_end_vma) #error Default tlb_flush() relies on default tlb_start_vma() and tlb_end_vma() #endif +/* + * When an architecture does not provide its own tlb_flush() implementation + * but does have a reasonably efficient flush_vma_range() implementation + * use that. + */ static inline void tlb_flush(struct mmu_gather *tlb) { if (tlb->fullmm || tlb->need_flush_all) { @@ -348,6 +385,8 @@ tlb_update_vma_flags(struct mmu_gather * #endif +#endif /* CONFIG_MMU_GATHER_NO_RANGE */ + static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb) { if (!tlb->end)