From patchwork Wed Jan 11 04:21:49 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 13095968 X-Patchwork-Delegate: kuba@kernel.org 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 61F0AC46467 for ; Wed, 11 Jan 2023 04:23:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235542AbjAKEXE (ORCPT ); Tue, 10 Jan 2023 23:23:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60840 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231478AbjAKEWW (ORCPT ); Tue, 10 Jan 2023 23:22:22 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E1505657F for ; Tue, 10 Jan 2023 20:22:21 -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=I7aASeW2bakt0a8pxVeEBiqLf4GO7WCoG44w/epo15A=; b=uSu5hoIgzDuHOgIJLcq8PNEDzt SDNRMpkVSmukNDELlT4wmw0nN8d0STryyMwkA+yq08u3WIKobL5OUpuLgNQR0ejpOVFDPXrN+cukw Bm/Nic1p/cRl8RdUNGMt349f4EXBtNG00qE5v8infB+/jfzTcKycMNzKUFkFBunH3rdEgsNk+fDXK 09RberagCyyu0kXSP+W4OOR/dNGz6yOgAXQ6bEXiuuCGMGP3GXkJpaV/AYh+XGR8iUzJ/PV2hk4kp JnVjwSQBBKGA46RWkMdbc4n3dEwzedYAFKtaDLtzvg7xNdGPeuc3X62IUi8mQ+3NcmmHrgxoUdwls NmEHsHIQ==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1pFScy-003nxi-8L; Wed, 11 Jan 2023 04:22:16 +0000 From: "Matthew Wilcox (Oracle)" To: Jesper Dangaard Brouer , Ilias Apalodimas Cc: "Matthew Wilcox (Oracle)" , netdev@vger.kernel.org, linux-mm@kvack.org, Shakeel Butt , Jesper Dangaard Brouer , Jesse Brandeburg Subject: [PATCH v3 01/26] netmem: Create new type Date: Wed, 11 Jan 2023 04:21:49 +0000 Message-Id: <20230111042214.907030-2-willy@infradead.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20230111042214.907030-1-willy@infradead.org> References: <20230111042214.907030-1-willy@infradead.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org As part of simplifying struct page, create a new netmem type which mirrors the page_pool members in struct page. Signed-off-by: Matthew Wilcox (Oracle) Acked-by: Jesper Dangaard Brouer Acked-by: Ilias Apalodimas Reviewed-by: Jesse Brandeburg --- Documentation/networking/page_pool.rst | 5 +++ include/net/page_pool.h | 46 ++++++++++++++++++++++++++ 2 files changed, 51 insertions(+) diff --git a/Documentation/networking/page_pool.rst b/Documentation/networking/page_pool.rst index 5db8c263b0c6..2c3c81473b97 100644 --- a/Documentation/networking/page_pool.rst +++ b/Documentation/networking/page_pool.rst @@ -221,3 +221,8 @@ Driver unload /* Driver unload */ page_pool_put_full_page(page_pool, page, false); xdp_rxq_info_unreg(&xdp_rxq); + +Functions and structures +======================== + +.. kernel-doc:: include/net/page_pool.h diff --git a/include/net/page_pool.h b/include/net/page_pool.h index 813c93499f20..cbea4df54918 100644 --- a/include/net/page_pool.h +++ b/include/net/page_pool.h @@ -50,6 +50,52 @@ PP_FLAG_DMA_SYNC_DEV |\ PP_FLAG_PAGE_FRAG) +/** + * struct netmem - A memory allocation from a &struct page_pool. + * @flags: The same as the page flags. Do not use directly. + * @pp_magic: Magic value to avoid recycling non page_pool allocated pages. + * @pp: The page pool this netmem was allocated from. + * @dma_addr: Call netmem_get_dma_addr() to read this value. + * @dma_addr_upper: Might need to be 64-bit on 32-bit architectures. + * @pp_frag_count: For frag page support, not supported in 32-bit + * architectures with 64-bit DMA. + * @_mapcount: Do not access this member directly. + * @_refcount: Do not access this member directly. Read it using + * netmem_ref_count() and manipulate it with netmem_get() and netmem_put(). + * + * This struct overlays struct page for now. Do not modify without a + * good understanding of the issues. + */ +struct netmem { + unsigned long flags; + unsigned long pp_magic; + struct page_pool *pp; + /* private: no need to document this padding */ + unsigned long _pp_mapping_pad; /* aliases with folio->mapping */ + /* public: */ + unsigned long dma_addr; + union { + unsigned long dma_addr_upper; + atomic_long_t pp_frag_count; + }; + atomic_t _mapcount; + atomic_t _refcount; +}; + +#define NETMEM_MATCH(pg, nm) \ + static_assert(offsetof(struct page, pg) == offsetof(struct netmem, nm)) +NETMEM_MATCH(flags, flags); +NETMEM_MATCH(lru, pp_magic); +NETMEM_MATCH(pp, pp); +NETMEM_MATCH(mapping, _pp_mapping_pad); +NETMEM_MATCH(dma_addr, dma_addr); +NETMEM_MATCH(dma_addr_upper, dma_addr_upper); +NETMEM_MATCH(pp_frag_count, pp_frag_count); +NETMEM_MATCH(_mapcount, _mapcount); +NETMEM_MATCH(_refcount, _refcount); +#undef NETMEM_MATCH +static_assert(sizeof(struct netmem) <= sizeof(struct page)); + /* * Fast allocation side cache array/stack *