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 1B0FAC433EF for ; Wed, 17 Nov 2021 11:52:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EF7FD61BD4 for ; Wed, 17 Nov 2021 11:52:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237032AbhKQLzD (ORCPT ); Wed, 17 Nov 2021 06:55:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48880 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236999AbhKQLzC (ORCPT ); Wed, 17 Nov 2021 06:55:02 -0500 Received: from mail-yb1-xb31.google.com (mail-yb1-xb31.google.com [IPv6:2607:f8b0:4864:20::b31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1AE7BC061570 for ; Wed, 17 Nov 2021 03:52:04 -0800 (PST) Received: by mail-yb1-xb31.google.com with SMTP id y68so6796407ybe.1 for ; Wed, 17 Nov 2021 03:52:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=IXJmB9DsrkP0Hl2X6TbOwJcxLtK5wGiHx+4l+DLgyu0=; b=UvbMV3fyqh6gAOb0SdTanMwPJxP/u4+ZL3yFDfKzV1czXOZixPZVswla4YNGlaenLr 2DEy1i1zqG2tkdnwMSE9O8bQcuFyULUcaaemhydffoKdJlzSTM4s0we6p1r0IiL+G0hh fjp1nklrcymDLzodFWHrg8DwSt6lN4TyT7b3WdJwp/wO8cac6NvWRTELTwUJfAGhetlm RQaODfMP4oI5RRf6Tnq2M8cPUJGJnhU+EfFn8rqdhlP+A9Zmf3+isI1QbteEbjukex08 06569AbcdlEuTVYeEBsqzQyjTQsynuwlbmbTwvtYdvcd/dCCQ/Un8d9C4QHY4r41JL9y LaKA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=IXJmB9DsrkP0Hl2X6TbOwJcxLtK5wGiHx+4l+DLgyu0=; b=Lme+MK2KNgqgxfdDzX5aoefpmOeVFkiQGvoQtFFcWB0iwMUOSIZs4vCgIGp5VrlEEL v9cC7swNh7m2HuOKBFBehzaBZ7q4PtxliFMTrBgTL1XPNbTh3f3UIClKwacM22Mi5A27 iUGUEe1HghCrDec9b5a+LZS5xHoRu6oeMn27zjj6QTWSpm8LJxFYHFkYBkDJCs2hXsDv 3Jv9/NwJf5rrEzNXYw69IDwribsduW/6w671fXvBCyjKs5Nbanx9PcRqfLbIO96fxOsK BB4x8+siLypLHzuoHZ3qkqmlT8zwpjNf9VLU3y62QoGCijGLq5//z49h25EUwPPe01zV gYPA== X-Gm-Message-State: AOAM531Bk0UM5ud/MQArSwGBcMrT5DEl7HbCARooZUfgIHGJNusjXHCZ khr3mSI3HoYUAsckyUOsFBPVg61rqPskex0An+f7SQ== X-Google-Smtp-Source: ABdhPJz2VtCKhzu8qZQihL+co6Mjb8uHqzCSoeW/gU9T0TjHNu8foK/mFxIYBP2LjWFnrz17Dbu/9zaW30o6I6X2Gy0= X-Received: by 2002:a25:c68a:: with SMTP id k132mr16877021ybf.531.1637149923308; Wed, 17 Nov 2021 03:52:03 -0800 (PST) MIME-Version: 1.0 References: <20211117075652.58299-1-linyunsheng@huawei.com> In-Reply-To: From: Ilias Apalodimas Date: Wed, 17 Nov 2021 13:51:27 +0200 Message-ID: Subject: Re: [PATCH net] page_pool: Revert "page_pool: disable dma mapping support..." To: Jesper Dangaard Brouer Cc: Yunsheng Lin , davem@davemloft.net, kuba@kernel.org, brouer@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linuxarm@openeuler.org, hawk@kernel.org, akpm@linux-foundation.org, peterz@infradead.org, vbabka@suse.cz, willy@infradead.org, will@kernel.org, feng.tang@intel.com, jgg@ziepe.ca, ebiederm@xmission.com, aarcange@redhat.com, guillaume.tucker@collabora.com, Linux-MM Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 17 Nov 2021 at 13:48, Jesper Dangaard Brouer wrote: > > Added CC: linux-mm@kvack.org > > On 17/11/2021 08.56, Yunsheng Lin wrote: > > 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(-) > > Acked-by: Jesper Dangaard Brouer > > Too bad that we have to keep this code-uglyness in struct page, and > handling in page_pool. Indeed :( Acked-by: Ilias Apalodimas > > > > 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; > > > > >