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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,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 D8F2AC43381 for ; Fri, 5 Mar 2021 04:19:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AE9D164FF0 for ; Fri, 5 Mar 2021 04:19:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229599AbhCEETR (ORCPT ); Thu, 4 Mar 2021 23:19:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44698 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229458AbhCEETN (ORCPT ); Thu, 4 Mar 2021 23:19:13 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AA715C061756; Thu, 4 Mar 2021 20:19:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=A+aKTxH1jcd4vDiytddTmJl7H4EV0ZPBIjE0cYaDNCI=; b=A4wG4jzqn9eHv9/2JTAvx+xA/U 25l66qpt/vLi9bDvZsHz9Zc3oJklrTMd2Qx8/HTrr6MrO4d9oq69lXC2c6GlXZ5akGhJBeKCvWudU 9Qncc7ku0kF+vAVL0yvGEFAfaiIzukYjYQ59Z49VvZIL3qRXCbtcHaMBYXXDrgOrjqLkLTRsmMBnw gs8as3GeHsTDPDENrkLFJQywPSh4JC1y9dULBcEowIIHUJbZMzGoJBi+2cyhFnERZLK1wFFhU8DjC AZgUqKCQQQSfvuURYACDnr3WUwcyvYDmmhbJqAwB4qriB3jednMywuMUxrNd2M6a/vlRfj6GDl/mM +XTB+qdw==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lI1vg-00A3SJ-7k; Fri, 05 Mar 2021 04:19:08 +0000 From: "Matthew Wilcox (Oracle)" To: linux-mm@kvack.org Cc: "Matthew Wilcox (Oracle)" , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH v4 01/25] mm: Introduce struct folio Date: Fri, 5 Mar 2021 04:18:37 +0000 Message-Id: <20210305041901.2396498-2-willy@infradead.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210305041901.2396498-1-willy@infradead.org> References: <20210305041901.2396498-1-willy@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org A struct folio refers to an entire (possibly compound) page. A function which takes a struct folio argument declares that it will operate on the entire compound page, not just PAGE_SIZE bytes. In return, the caller guarantees that the pointer it is passing does not point to a tail page. Signed-off-by: Matthew Wilcox (Oracle) --- include/linux/mm.h | 30 ++++++++++++++++++++++++++++++ include/linux/mm_types.h | 17 +++++++++++++++++ 2 files changed, 47 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index 77e64e3eac80..a46e5a4385b0 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -927,6 +927,11 @@ static inline unsigned int compound_order(struct page *page) return page[1].compound_order; } +static inline unsigned int folio_order(struct folio *folio) +{ + return compound_order(&folio->page); +} + static inline bool hpage_pincount_available(struct page *page) { /* @@ -1518,6 +1523,30 @@ static inline void set_page_links(struct page *page, enum zone_type zone, #endif } +static inline unsigned long folio_nr_pages(struct folio *folio) +{ + return compound_nr(&folio->page); +} + +static inline struct folio *next_folio(struct folio *folio) +{ +#if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP) + return (struct folio *)nth_page(&folio->page, folio_nr_pages(folio)); +#else + return folio + folio_nr_pages(folio); +#endif +} + +static inline unsigned int folio_shift(struct folio *folio) +{ + return PAGE_SHIFT + folio_order(folio); +} + +static inline size_t folio_size(struct folio *folio) +{ + return PAGE_SIZE << folio_order(folio); +} + /* * Some inline functions in vmstat.h depend on page_zone() */ @@ -1623,6 +1652,7 @@ extern void pagefault_out_of_memory(void); #define offset_in_page(p) ((unsigned long)(p) & ~PAGE_MASK) #define offset_in_thp(page, p) ((unsigned long)(p) & (thp_size(page) - 1)) +#define offset_in_folio(folio, p) ((unsigned long)(p) & (folio_size(folio) - 1)) /* * Flags passed to show_mem() and show_free_areas() to suppress output in diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 0974ad501a47..a311cb48526f 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -223,6 +223,23 @@ struct page { #endif } _struct_page_alignment; +/* + * A struct folio is either a base (order-0) page or the head page of + * a compound page. + */ +struct folio { + struct page page; +}; + +static inline struct folio *page_folio(struct page *page) +{ + unsigned long head = READ_ONCE(page->compound_head); + + if (unlikely(head & 1)) + return (struct folio *)(head - 1); + return (struct folio *)page; +} + static inline atomic_t *compound_mapcount_ptr(struct page *page) { return &page[1].compound_mapcount; -- 2.30.0