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=-8.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 A2869C433B4 for ; Fri, 16 Apr 2021 15:30:56 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6DA71611BF for ; Fri, 16 Apr 2021 15:30:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6DA71611BF Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Cz3LBqUkiAezfkoUsKin44bVIEV0dgXoGUT1Tjd2fDo=; b=D1nL5gx0eZq5CRV8cyjYVMmC/ w5Q4wUZMoV9niaQ332LzzPypaXP3flm//mRj40ElP4tQSAoIP9+ha9SiqEok+aKwHW3DdO0KMV6cw N30K1sg58rd/zvGLFRCphiveSAtHO+g3h/tu35by312/qhhlZ39YV3gpmUmMltFID5zrhgTvcsk5t h3iTFX7oehlcvgUCm3Jyix6eRSvO5vEGoWovsPzySXjcjoXmp9fBt0SOmTKOJ79Oe98Tcx4gF6H4B UCejJ/9yGOa89u0ci/O4/UUD29oGplSvYHq/kWmHKs/3wDyD7VtE8CL9U7700zOTy9Pqzz5ai7PPy dQCJdNntQ==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lXQP3-002cuo-Iz; Fri, 16 Apr 2021 15:29:05 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lXQP1-002cuP-30 for linux-arm-kernel@desiato.infradead.org; Fri, 16 Apr 2021 15:29:03 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=1toLz+6Q9HQNcw3MQRhWkEtoAVrOWnWFJOtvRcLCOTo=; b=AfDcl5h/43wjmPGPvOHoHHxUtH VUrHqD3LImr52YJgVp8v99CpXw49O+3ABZxg5dh2xjPUhMw9cBqhZ/eHIxjqVBmWAJ5j2VFJliPqP BQOm1fzjrGaws2wsSyby1unfkL+/Wxc1aXKKpQCeRlWZhNlLgNueCFlXNMIQiSGoqCfvjgZ9Is6GB hFY2A2C7bLXBzhULxoFqzdLwiH6FLDnAub0LrzdQzZam5myqe1duHZgtATotK/lfgrQQkIZGYhNry QenDpI12d1AnF7t8sVRmpZ4hU7p/p1rPmDOPveX4AC6sl4F0D+bQ9ZY+9PGK+tPLJDf+e8Y0+WANo iep2axvg==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lXQNv-00A7Ug-LK; Fri, 16 Apr 2021 15:28:22 +0000 Date: Fri, 16 Apr 2021 16:27:55 +0100 From: Matthew Wilcox To: Jesper Dangaard Brouer Cc: David Laight , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "netdev@vger.kernel.org" , "linuxppc-dev@lists.ozlabs.org" , "linux-arm-kernel@lists.infradead.org" , "linux-mips@vger.kernel.org" , Ilias Apalodimas , Matteo Croce , Grygorii Strashko , Arnd Bergmann , Christoph Hellwig Subject: Re: [PATCH 1/1] mm: Fix struct page layout on 32-bit systems Message-ID: <20210416152755.GL2531743@casper.infradead.org> References: <20210410205246.507048-2-willy@infradead.org> <20210411114307.5087f958@carbon> <20210411103318.GC2531743@casper.infradead.org> <20210412011532.GG2531743@casper.infradead.org> <20210414101044.19da09df@carbon> <20210414115052.GS2531743@casper.infradead.org> <20210414211322.3799afd4@carbon> <20210414213556.GY2531743@casper.infradead.org> <20210415200832.32796445@carbon> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210415200832.32796445@carbon> X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Apr 15, 2021 at 08:08:32PM +0200, Jesper Dangaard Brouer wrote: > See below patch. Where I swap32 the dma address to satisfy > page->compound having bit zero cleared. (It is the simplest fix I could > come up with). I think this is slightly simpler, and as a bonus code that assumes the old layout won't compile. diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 6613b26a8894..5aacc1c10a45 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -97,10 +97,10 @@ struct page { }; struct { /* page_pool used by netstack */ /** - * @dma_addr: might require a 64-bit value even on + * @dma_addr: might require a 64-bit value on * 32-bit architectures. */ - dma_addr_t dma_addr; + unsigned long dma_addr[2]; }; struct { /* slab, slob and slub */ union { diff --git a/include/net/page_pool.h b/include/net/page_pool.h index b5b195305346..db7c7020746a 100644 --- a/include/net/page_pool.h +++ b/include/net/page_pool.h @@ -198,7 +198,17 @@ static inline void page_pool_recycle_direct(struct page_pool *pool, static inline dma_addr_t page_pool_get_dma_addr(struct page *page) { - return page->dma_addr; + dma_addr_t ret = page->dma_addr[0]; + if (sizeof(dma_addr_t) > sizeof(unsigned long)) + ret |= (dma_addr_t)page->dma_addr[1] << 32; + return ret; +} + +static inline void page_pool_set_dma_addr(struct page *page, dma_addr_t addr) +{ + page->dma_addr[0] = addr; + if (sizeof(dma_addr_t) > sizeof(unsigned long)) + page->dma_addr[1] = addr >> 32; } static inline bool is_page_pool_compiled_in(void) diff --git a/net/core/page_pool.c b/net/core/page_pool.c index ad8b0707af04..f014fd8c19a6 100644 --- a/net/core/page_pool.c +++ b/net/core/page_pool.c @@ -174,8 +174,10 @@ static void page_pool_dma_sync_for_device(struct page_pool *pool, struct page *page, unsigned int dma_sync_size) { + dma_addr_t dma_addr = page_pool_get_dma_addr(page); + dma_sync_size = min(dma_sync_size, pool->p.max_len); - dma_sync_single_range_for_device(pool->p.dev, page->dma_addr, + dma_sync_single_range_for_device(pool->p.dev, dma_addr, pool->p.offset, dma_sync_size, pool->p.dma_dir); } @@ -226,7 +228,7 @@ static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool, put_page(page); return NULL; } - page->dma_addr = dma; + page_pool_set_dma_addr(page, dma); if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) page_pool_dma_sync_for_device(pool, page, pool->p.max_len); @@ -294,13 +296,13 @@ void page_pool_release_page(struct page_pool *pool, struct page *page) */ goto skip_dma_unmap; - dma = page->dma_addr; + dma = page_pool_get_dma_addr(page); - /* When page is unmapped, it cannot be returned our pool */ + /* When page is unmapped, it cannot be returned to our pool */ dma_unmap_page_attrs(pool->p.dev, dma, PAGE_SIZE << pool->p.order, pool->p.dma_dir, DMA_ATTR_SKIP_CPU_SYNC); - page->dma_addr = 0; + page_pool_set_dma_addr(page, 0); skip_dma_unmap: /* This may be the last page returned, releasing the pool, so * it is not safe to reference pool afterwards. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel