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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6C54FC433EF for ; Wed, 17 Nov 2021 07:59:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4EE8963222 for ; Wed, 17 Nov 2021 07:59:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234312AbhKQICN (ORCPT ); Wed, 17 Nov 2021 03:02:13 -0500 Received: from szxga01-in.huawei.com ([45.249.212.187]:14948 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231967AbhKQICJ (ORCPT ); Wed, 17 Nov 2021 03:02:09 -0500 Received: from dggemv704-chm.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4HvFct2z1zzZd74; Wed, 17 Nov 2021 15:56:46 +0800 (CST) Received: from dggpemm500005.china.huawei.com (7.185.36.74) by dggemv704-chm.china.huawei.com (10.3.19.47) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Wed, 17 Nov 2021 15:59:01 +0800 Received: from localhost.localdomain (10.69.192.56) by dggpemm500005.china.huawei.com (7.185.36.74) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Wed, 17 Nov 2021 15:59:01 +0800 From: Yunsheng Lin To: , CC: , , , , , , , , , , , , , , Subject: [PATCH net] page_pool: Revert "page_pool: disable dma mapping support..." Date: Wed, 17 Nov 2021 15:56:52 +0800 Message-ID: <20211117075652.58299-1-linyunsheng@huawei.com> X-Mailer: git-send-email 2.33.0 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.69.192.56] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpemm500005.china.huawei.com (7.185.36.74) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This reverts commit d00e60ee54b12de945b8493cf18c1ada9e422514. As reported by Guillaume in [1]: Enabling LPAE always enables CONFIG_ARCH_DMA_ADDR_T_64BIT in 32-bit systems, which breaks the bootup proceess when a ethernet driver is using page pool with PP_FLAG_DMA_MAP flag. As we were hoping we had no active consumers for such system when we removed the dma mapping support, and LPAE seems like a common feature for 32 bits system, so revert it. 1. https://www.spinics.net/lists/netdev/msg779890.html Fixes: d00e60ee54b1 ("page_pool: disable dma mapping support for 32-bit arch with 64-bit DMA") Signed-off-by: Yunsheng Lin --- include/linux/mm_types.h | 13 ++++++++++++- include/net/page_pool.h | 12 +++++++++++- net/core/page_pool.c | 10 ++++------ 3 files changed, 27 insertions(+), 8 deletions(-) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index bb8c6f5f19bc..c3a6e6209600 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -105,7 +105,18 @@ struct page { struct page_pool *pp; unsigned long _pp_mapping_pad; unsigned long dma_addr; - atomic_long_t pp_frag_count; + union { + /** + * dma_addr_upper: might require a 64-bit + * value on 32-bit architectures. + */ + unsigned long dma_addr_upper; + /** + * For frag page support, not supported in + * 32-bit architectures with 64-bit DMA. + */ + atomic_long_t pp_frag_count; + }; }; struct { /* slab, slob and slub */ union { diff --git a/include/net/page_pool.h b/include/net/page_pool.h index 3855f069627f..a4082406a003 100644 --- a/include/net/page_pool.h +++ b/include/net/page_pool.h @@ -216,14 +216,24 @@ static inline void page_pool_recycle_direct(struct page_pool *pool, page_pool_put_full_page(pool, page, true); } +#define PAGE_POOL_DMA_USE_PP_FRAG_COUNT \ + (sizeof(dma_addr_t) > sizeof(unsigned long)) + static inline dma_addr_t page_pool_get_dma_addr(struct page *page) { - return page->dma_addr; + dma_addr_t ret = page->dma_addr; + + if (PAGE_POOL_DMA_USE_PP_FRAG_COUNT) + ret |= (dma_addr_t)page->dma_addr_upper << 16 << 16; + + return ret; } static inline void page_pool_set_dma_addr(struct page *page, dma_addr_t addr) { page->dma_addr = addr; + if (PAGE_POOL_DMA_USE_PP_FRAG_COUNT) + page->dma_addr_upper = upper_32_bits(addr); } static inline void page_pool_set_frag_count(struct page *page, long nr) diff --git a/net/core/page_pool.c b/net/core/page_pool.c index 9b60e4301a44..1a6978427d6c 100644 --- a/net/core/page_pool.c +++ b/net/core/page_pool.c @@ -49,12 +49,6 @@ static int page_pool_init(struct page_pool *pool, * which is the XDP_TX use-case. */ if (pool->p.flags & PP_FLAG_DMA_MAP) { - /* DMA-mapping is not supported on 32-bit systems with - * 64-bit DMA mapping. - */ - if (sizeof(dma_addr_t) > sizeof(unsigned long)) - return -EOPNOTSUPP; - if ((pool->p.dma_dir != DMA_FROM_DEVICE) && (pool->p.dma_dir != DMA_BIDIRECTIONAL)) return -EINVAL; @@ -75,6 +69,10 @@ static int page_pool_init(struct page_pool *pool, */ } + if (PAGE_POOL_DMA_USE_PP_FRAG_COUNT && + pool->p.flags & PP_FLAG_PAGE_FRAG) + return -EINVAL; + if (ptr_ring_init(&pool->ring, ring_qsize, GFP_KERNEL) < 0) return -ENOMEM; -- 2.33.0