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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E0367C433F5 for ; Fri, 11 Feb 2022 22:47:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346513AbiBKWrj (ORCPT ); Fri, 11 Feb 2022 17:47:39 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:40248 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234271AbiBKWri (ORCPT ); Fri, 11 Feb 2022 17:47:38 -0500 X-Greylist: delayed 12258 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Fri, 11 Feb 2022 14:47:35 PST Received: from mail.skyhub.de (mail.skyhub.de [5.9.137.197]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BE7E2D54; Fri, 11 Feb 2022 14:47:35 -0800 (PST) Received: from zn.tnic (dslb-088-067-221-104.088.067.pools.vodafone-ip.de [88.67.221.104]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 40DD31EC0373; Fri, 11 Feb 2022 23:47:30 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1644619650; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=2LCnjyoUFVPe/KzjUBCJiTmbTvN8cuqDLjqJCXV4ReQ=; b=IxFzfRaDSnpa0XIsdWZwnQsOS1FLnRddCJ3scnDVyeT2ISmvJvhZVz6i7pxf2Qftqlvzps zaZJ+UKNXLX/8b7M17TUgCNqtU1tfsM9uvJABVTKFtFWaQC3D+Ure7KZ1uuvoyzlGLGKrY PQHawl9oV8uDr6CfcsvIxrESQebaOLk= Date: Fri, 11 Feb 2022 23:47:31 +0100 From: Borislav Petkov To: Yazen Ghannam Cc: linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org, mchehab@kernel.org, tony.luck@intel.com, james.morse@arm.com, rric@kernel.org, Smita.KoralahalliChannabasappa@amd.com Subject: Re: [PATCH v4 07/24] EDAC/amd64: Define function to dehash address Message-ID: References: <20220127204115.384161-1-yazen.ghannam@amd.com> <20220127204115.384161-8-yazen.ghannam@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20220127204115.384161-8-yazen.ghannam@amd.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 27, 2022 at 08:40:58PM +0000, Yazen Ghannam wrote: > Move the dehashing code into a separate helper function. Define a > DF2-specific function for the current code. Specific helper functions > will be added for future DF versions. > > The dehashing function used is based on the interleaving mode rather > than the Data Fabric version. So save the function pointer in the > context struct. The use of "df2" in the name of the current function is > only because the interleaving mode using it only appears on Data Fabric > 2 systems. > > Signed-off-by: Yazen Ghannam > --- > Link: > https://lore.kernel.org/r/20211028175728.121452-12-yazen.ghannam@amd.com > > v3->v4: > * Include pr_debug() on failure. > > v2->v3: > * Was patch 12 in v2. > > v1->v2: > * Moved from arch/x86 to EDAC. > * Add new function pointer in ctx struct. > > drivers/edac/amd64_edac.c | 36 +++++++++++++++++++++--------------- > 1 file changed, 21 insertions(+), 15 deletions(-) > > diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c > index 350204eadb27..da2d0d9ce406 100644 > --- a/drivers/edac/amd64_edac.c > +++ b/drivers/edac/amd64_edac.c > @@ -1077,7 +1077,7 @@ struct addr_ctx { > u8 map_num; > u8 intlv_addr_bit; > u8 cs_id; > - bool hash_enabled; > + int (*dehash_addr)(struct addr_ctx *ctx); A function pointer in a context struct?! > @@ -1357,18 +1372,9 @@ static int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr > goto out_err; > } > > - if (ctx.hash_enabled) { > - /* Save some parentheses and grab ls-bit at the end. */ > - hashed_bit = (ctx.ret_addr >> 12) ^ > - (ctx.ret_addr >> 18) ^ > - (ctx.ret_addr >> 21) ^ > - (ctx.ret_addr >> 30) ^ > - ctx.cs_id; > - > - hashed_bit &= BIT(0); > - > - if (hashed_bit != ((ctx.ret_addr >> ctx.intlv_addr_bit) & BIT(0))) > - ctx.ret_addr ^= BIT(ctx.intlv_addr_bit); > + if (ctx.dehash_addr && ctx.dehash_addr(&ctx)) { So you can just as well do: if (ctx->intlv_mode == 8) dehash_addr(); And dehash_addr() can inside determine whether df2 or df3. Btw, that 8 looks like magic. It should be a #define. What you have now looks a bit weird with those function pointers lumped together with those other members of addr_ctx. Dunno, maybe it'll make more sense when I read the rest first... -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette