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 22D9BC43334 for ; Thu, 23 Jun 2022 09:36:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229761AbiFWJgO (ORCPT ); Thu, 23 Jun 2022 05:36:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39598 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230323AbiFWJgN (ORCPT ); Thu, 23 Jun 2022 05:36:13 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4EC574969C; Thu, 23 Jun 2022 02:36:09 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 06D691FD84; Thu, 23 Jun 2022 09:36:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1655976968; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=k0mbNIM+JB6w795iF5JgVuU7GedW8ezpGnJMdaZLqFc=; b=J8QALNxCEW1OJSBo0kJeIxMjIArt6h8Re6hB6BbVQA/4gULvEBrBTNTLe+6MwkNfs3MdhM +U2JuSV0CPigje0U5klJwA1qVPVYX2JWk26XVFAjO7P3dCaYeUdQIlAqdQlOJMReUJwNUn exQz9aVA+NftUov4Qz+/5SsUaH0d4Gg= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1655976968; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=k0mbNIM+JB6w795iF5JgVuU7GedW8ezpGnJMdaZLqFc=; b=dBgp1ATEUkJdvyO973sUrTj+pbMGITd6mg1TDpSBc9TVhJc58UU/R0cB06TqI2yvifWQML K7sD1WPwEYxPXSCQ== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id BF225133A6; Thu, 23 Jun 2022 09:36:07 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id LrcyLQc0tGLMKgAAMHmgww (envelope-from ); Thu, 23 Jun 2022 09:36:07 +0000 Date: Thu, 23 Jun 2022 11:36:06 +0200 From: Yousaf Kaukab To: Mikko Perttunen Cc: Thierry Reding , Jonathan Hunter , Greg Kroah-Hartman , Mikko Perttunen , linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] arm64: tegra: Mark BPMP channels as no-memory-wc Message-ID: <20220623093606.GA181983@suse.de> References: <20220622132300.1746201-1-cyndis@kapsi.fi> <20220622132300.1746201-2-cyndis@kapsi.fi> <9e80da1f-60e9-5528-3636-6443461fb207@kapsi.fi> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <9e80da1f-60e9-5528-3636-6443461fb207@kapsi.fi> Precedence: bulk List-ID: X-Mailing-List: linux-tegra@vger.kernel.org On Wed, Jun 22, 2022 at 04:29:03PM +0300, Mikko Perttunen wrote: > On 22.6.2022 16.23, Mikko Perttunen wrote: > > From: Mikko Perttunen > > > > The Tegra SYSRAM contains regions access to which is restricted to > > certain hardware blocks on the system, and speculative accesses to > > those will cause issues. > > > > Patch 'misc: sram: Only map reserved areas in Tegra SYSRAM' attempted > > to resolve this by only mapping the regions specified in the device > > tree on the assumption that there are no such restricted areas within > > the 64K-aligned area of memory that contains the memory we wish to map. > > > > Turns out this assumption is wrong, as there are such areas above the > > 4K pages described in the device trees. As such, we need to use the > > bigger hammer that is no-memory-wc, which causes the memory to be > > mapped as Device memory to which speculative accesses are disallowed. > > > > As such, the previous patch in the series, > > 'firmware: tegra: bpmp: do only aligned access to IPC memory area', > > is required with this patch to make the BPMP driver only issue aligned > > memory accesses as those are also required with Device memory. > > > > Fixes: fec29bf04994 ("misc: sram: Only map reserved areas in Tegra SYSRAM") > > Signed-off-by: Mikko Perttunen > > --- > > FWIW, with this, the aforementioned patch to misc/sram is redundant. It > doesn't hurt, but doesn't really help either. Whether or not it should be > reverted, I have no opinion. I am in favor of reverting commit fec29bf04994 ("misc: sram: Only map reserved areas in Tegra SYSRAM"). Tegra platforms are the only consumer of this code. I consider it to be redundant after your series. For both patches: Reviewed-by: Yousaf Kaukab > > Thanks, > Mikko BR, Yousaf