Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932821Ab0FQMOA (ORCPT ); Thu, 17 Jun 2010 08:14:00 -0400 Received: from sh.osrg.net ([192.16.179.4]:59830 "EHLO sh.osrg.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932742Ab0FQMN4 (ORCPT ); Thu, 17 Jun 2010 08:13:56 -0400 Date: Thu, 17 Jun 2010 21:13:44 +0900 To: mchan@broadcom.com Cc: vapier@gentoo.org, JBottomley@Novell.com, netdev@vger.kernel.org, linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org, fujita.tomonori@lab.ntt.co.jp Subject: Re: bnx2 fails to compile on parisc because of missing get_dma_ops() From: FUJITA Tomonori In-Reply-To: References: Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-Id: <20100617211203O.fujita.tomonori@lab.ntt.co.jp> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-3.0 (sh.osrg.net [192.16.179.4]); Thu, 17 Jun 2010 21:13:44 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3420 Lines: 107 On Wed, 16 Jun 2010 20:53:57 -0700 "Michael Chan" wrote: > > > The commit that causes the problem: > > > > > > commit a33fa66bcf365ffe5b79d1ae1d3582cc261ae56e > > > Author: Michael Chan > > > Date: Thu May 6 08:58:13 2010 +0000 > > > > > > bnx2: Add prefetches to rx path. > > > > > > Looks fairly innocuous by the description. > > > > > > Should parisc have a get_dma_ops()? We don't need one > > because our dma > > > ops are per platform not per bus. > > > > looks like it'll be broken on more than just parisc: > > $ grep get_dma_ops arch/*/include/asm/ -rl | cut -d/ -f 2 > > alpha > > ia64 > > microblaze > > powerpc > > sh > > sparc > > x86 > > Most of these archs use the dma functions in: > > > > so it's not a problem. No, it's wrong assumption. asm-genric/dma-mapping-common.h is the helper code to simplify architecture's DMA core code. Some architecture uses it and some don't. You can't expect every architectures to use it. > I think I'll send in a patch to remove that part of the code > from bnx2.c for now. Yeah. I'm not sure you already sent a patch. = From: FUJITA Tomonori Date: Thu, 17 Jun 2010 13:06:15 +0900 Subject: [PATCH] bnx2: fix dma_get_ops compilation breakage This removes dma_get_ops() prefetch optimization in bnx2. bnx2 uses dma_get_ops() to see if dma_sync_single_for_cpu() is noop. bnx2 does prefetch if it's noop. But dma_get_ops() isn't available on all the architectures (only the architectures that uses dma_map_ops struct have it). Using dma_get_ops() in drivers leads to compilation breakage on many archtectures. Currently, we don't have a way to see if dma_sync_single_for_cpu() is noop. If it can improve the performance notably, we can add the new DMA API for it. Signed-off-by: FUJITA Tomonori --- drivers/net/bnx2.c | 10 +--------- 1 files changed, 1 insertions(+), 9 deletions(-) diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c index 949d7a9..b3305fc 100644 --- a/drivers/net/bnx2.c +++ b/drivers/net/bnx2.c @@ -3073,7 +3073,6 @@ bnx2_rx_int(struct bnx2 *bp, struct bnx2_napi *bnapi, int budget) u16 hw_cons, sw_cons, sw_ring_cons, sw_prod, sw_ring_prod; struct l2_fhdr *rx_hdr; int rx_pkt = 0, pg_ring_used = 0; - struct pci_dev *pdev = bp->pdev; hw_cons = bnx2_get_hw_rx_cons(bnapi); sw_cons = rxr->rx_cons; @@ -3086,7 +3085,7 @@ bnx2_rx_int(struct bnx2 *bp, struct bnx2_napi *bnapi, int budget) while (sw_cons != hw_cons) { unsigned int len, hdr_len; u32 status; - struct sw_bd *rx_buf, *next_rx_buf; + struct sw_bd *rx_buf; struct sk_buff *skb; dma_addr_t dma_addr; u16 vtag = 0; @@ -3098,13 +3097,6 @@ bnx2_rx_int(struct bnx2 *bp, struct bnx2_napi *bnapi, int budget) rx_buf = &rxr->rx_buf_ring[sw_ring_cons]; skb = rx_buf->skb; prefetchw(skb); - - if (!get_dma_ops(&pdev->dev)->sync_single_for_cpu) { - next_rx_buf = - &rxr->rx_buf_ring[ - RX_RING_IDX(NEXT_RX_BD(sw_cons))]; - prefetch(next_rx_buf->desc); - } rx_buf->skb = NULL; dma_addr = dma_unmap_addr(rx_buf, mapping); -- 1.5.6.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/