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=-8.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 29037C43381 for ; Mon, 4 Mar 2019 12:42:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B98F820830 for ; Mon, 4 Mar 2019 12:42:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="B29km6Np" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726567AbfCDMl7 (ORCPT ); Mon, 4 Mar 2019 07:41:59 -0500 Received: from merlin.infradead.org ([205.233.59.134]:43966 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726181AbfCDMl7 (ORCPT ); Mon, 4 Mar 2019 07:41:59 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.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:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=mlAtjb/BpRzlbTczCYrs9gwKr+YvBuNFP5mfUazYSqo=; b=B29km6Np7863VXL6Iimoqw06i Zo8HkhjNNPYjGdz+UhHp+OCI3aBbnPtjQGNEYE2zKmRQUv8QeHjew6dc6okMpaJRa4eZATOOXuxQL ATjmoUqohC+TaH3+6ldziSW3/7TBG1k275H0fVlZv1fh4olRwn8N/C9+QiZ/6bWTZ5h4tF9BEex94 e1fad7bcD/66lg+0wFHxa0wxq7iWx6T15Xou9+N8c8k+BqdjSvnyMbqhuF1ll4bjQgww6OYPUG3a6 ysy1TNcDC6gWU9IFnILlUbOWU6hGwJdK/FkdnfmXg8JzaZnYk6k8zxkInM0nmkQdCgIWiKSxIV93i 8T+ZtrFgw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1h0mug-0004Lt-Md; Mon, 04 Mar 2019 12:41:47 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 35B2F20295395; Mon, 4 Mar 2019 13:41:44 +0100 (CET) Date: Mon, 4 Mar 2019 13:41:44 +0100 From: Peter Zijlstra To: Paolo Bonzini Cc: Fenghua Yu , Thomas Gleixner , Ingo Molnar , Borislav Petkov , H Peter Anvin , Dave Hansen , Ashok Raj , Ravi V Shankar , Xiaoyao Li , linux-kernel , x86 , kvm@vger.kernel.org Subject: Re: [PATCH v4 03/17] wlcore: Align reg_ch_conf_pending and tmp_ch_bitmap to unsigned long for better performance Message-ID: <20190304124144.GD32477@hirez.programming.kicks-ass.net> References: <1551494711-213533-1-git-send-email-fenghua.yu@intel.com> <1551494711-213533-4-git-send-email-fenghua.yu@intel.com> <20190304101141.GB32477@hirez.programming.kicks-ass.net> <44bb6771-7aea-c44d-6605-45e7a1499d1b@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <44bb6771-7aea-c44d-6605-45e7a1499d1b@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 04, 2019 at 11:46:52AM +0100, Paolo Bonzini wrote: > From: Paolo Bonzini > Subject: [PATCH] wlcore: simplify/fix/optimize reg_ch_conf_pending operations > > Bitmaps are defined on unsigned longs, so the usage of u32[2] in the > wlcore driver is incorrect. As noted by Peter Zijlstra, casting arrays > to a bitmap is incorrect for big-endian architectures. > > When looking at it I observed that: > > - operations on reg_ch_conf_pending is always under the wl_lock mutex, > so set_bit is overkill > > - the only case where reg_ch_conf_pending is accessed a u32 at a time is > unnecessary too. > > This patch cleans up everything in this area, and changes tmp_ch_bitmap > to have the proper alignment. > > Reported-by: Fenghua Yu > Signed-off-by: Paolo Bonzini > > diff --git a/drivers/net/wireless/ti/wlcore/cmd.c b/drivers/net/wireless/ti/wlcore/cmd.c > index 903968735a74..3e093f3a7ec8 100644 > --- a/drivers/net/wireless/ti/wlcore/cmd.c > +++ b/drivers/net/wireless/ti/wlcore/cmd.c > @@ -1700,14 +1700,14 @@ void wlcore_set_pending_regdomain_ch(struct wl1271 *wl, u16 channel, > ch_bit_idx = wlcore_get_reg_conf_ch_idx(band, channel); > > if (ch_bit_idx >= 0 && ch_bit_idx <= WL1271_MAX_CHANNELS) > - set_bit(ch_bit_idx, (long *)wl->reg_ch_conf_pending); > + __set_bit_le(ch_bit_idx, (long *)wl->reg_ch_conf_pending); > } > > int wlcore_cmd_regdomain_config_locked(struct wl1271 *wl) > { > struct wl12xx_cmd_regdomain_dfs_config *cmd = NULL; > int ret = 0, i, b, ch_bit_idx; > - u32 tmp_ch_bitmap[2]; > + u32 tmp_ch_bitmap[2] __aligned(sizeof(unsigned long)); Also mark it as __le32 ? > struct wiphy *wiphy = wl->hw->wiphy; > struct ieee80211_supported_band *band; > bool timeout = false; > @@ -1717,7 +1717,7 @@ int wlcore_cmd_regdomain_config_locked(struct wl1271 *wl) > > wl1271_debug(DEBUG_CMD, "cmd reg domain config"); > > - memset(tmp_ch_bitmap, 0, sizeof(tmp_ch_bitmap)); > + memcpy(tmp_ch_bitmap, wl->reg_ch_conf_pending, sizeof(tmp_ch_bitmap)); How about using: bitmap_to_arr32(tmp_ch_bitmap, wl->reg_ch_conf_pending, sizeof(tmp_ch_bitmap)); for (i=0; i<2; i++) tmp_ch_bitmap[i] = cpu_to_le32(tmp_ch_bitmap[i]); (or add bitmap_to_arr32_le ?) > for (b = NL80211_BAND_2GHZ; b <= NL80211_BAND_5GHZ; b++) { > band = wiphy->bands[b]; > @@ -1738,13 +1738,10 @@ int wlcore_cmd_regdomain_config_locked(struct wl1271 *wl) > if (ch_bit_idx < 0) > continue; > > - set_bit(ch_bit_idx, (long *)tmp_ch_bitmap); > + __set_bit_le(ch_bit_idx, (long *)tmp_ch_bitmap); But you copied in reg_ch_conf_pending without doing an LE swizzle. With the proposed change, we have two __le32 here and it works again. > } > } > > - tmp_ch_bitmap[0] |= wl->reg_ch_conf_pending[0]; > - tmp_ch_bitmap[1] |= wl->reg_ch_conf_pending[1]; > - > if (!memcmp(tmp_ch_bitmap, wl->reg_ch_conf_last, sizeof(tmp_ch_bitmap))) > goto out; > And then remove the cpu_to_le32() on assignment to ch_bit_map*. > diff --git a/drivers/net/wireless/ti/wlcore/wlcore.h b/drivers/net/wireless/ti/wlcore/wlcore.h > index dd14850b0603..870eea3e7a27 100644 > --- a/drivers/net/wireless/ti/wlcore/wlcore.h > +++ b/drivers/net/wireless/ti/wlcore/wlcore.h > @@ -320,9 +320,9 @@ struct wl1271 { > bool watchdog_recovery; > > /* Reg domain last configuration */ > - u32 reg_ch_conf_last[2] __aligned(8); > + DECLARE_BITMAP(reg_ch_conf_last, 64); Is never actually used as a bitmap but used as opaque storage with memcpy and memcmp against tmp_ch_bitmap. > /* Reg domain pending configuration */ > - u32 reg_ch_conf_pending[2]; > + DECLARE_BITMAP(reg_ch_conf_pending, 64); > > /* Pointer that holds DMA-friendly block for the mailbox */ > void *mbox;