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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 05F22C761A6 for ; Tue, 4 Apr 2023 19:30:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: List-Subscribe:List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: In-Reply-To:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Reply-To:Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date :Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=UUJYXo9a5oJ1sTU3Tm0Zfkcz/el0hG3dToudxLsoEmU=; b=iDE0Izq8dOjjqWf/LChU9vEHMN P7/PNfNrWn9uxYhfuO6JwLs5ur0SVKrPYm6Akv1b0OhNYI9SrbE58dDBogvWnnAk7eXOfi8uSEWzD 77J4enwTu4sdk2Acqu6xoCNEXQ0XM3akeiVinlZ5fcBs45Oyp9hLp4nvnNLTCeLepiadLUqevzBlF USRTdbJ+jlMfyWQOt8y4qwHCb7MLIEakWEyRgS1FWQRrMk14l/11kO2AOzJKNgdOKVhWoKX8vBBtA bqdOuaToREJo9mOfVoNB04Wb1PSjWs9vwUk8P4UWdpaeA2A811sv54nwkBhrj7wYIDa4ipf7snNVo myfO/e3g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pjmLt-002eBb-1u; Tue, 04 Apr 2023 19:29:57 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1pjmLp-002eB7-1d for linux-arm-kernel@lists.infradead.org; Tue, 04 Apr 2023 19:29:56 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1CAEC63406; Tue, 4 Apr 2023 19:29:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2EB65C433EF; Tue, 4 Apr 2023 19:29:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1680636591; bh=lxOKTCvPksW7Jtj6LMV9HNZS1AI82kjwKyiRLo8C7FE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=l+uJnlv8xhTy2338ZnQ4Gq34nsIqMcWrTCp27aiqvH04bHG4bgYg2WfsOIYroFEjw BXZGR742UYZ4vYXtcmL3I00/xxMy28CXZSnjsQRM+Vcfh8gDHqKs7znupt1zfZVrxW ONGkBw1f+HR/R3CZ8M6seUDuajaXaV49FeB3Uj0b/jFdeAcHBR7/c9YlwzOPOwYRJq uZwXi5QnMhBlkQINy7DqPPBRTDwcZbcNzOm8QdxIN6dm2MIFT9v8wyS0vnYjYWm1zP PxNjuYC3pWOeG7bLjlDKN9qfH8CHAoWYU6AmDcBYrtUYNfEYvWVAd1osyRTKrXxtpc tstkB9ggmQzzQ== Date: Tue, 4 Apr 2023 20:29:46 +0100 From: Conor Dooley To: Pierre Gondois Cc: linux-kernel@vger.kernel.org, Radu Rendec , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , "Rafael J. Wysocki" , Sudeep Holla , Akihiko Odaki , Palmer Dabbelt , Gavin Shan , Jeremy Linton , linux-arm-kernel@lists.infradead.org, Alexandre Ghiti Subject: Re: [PATCH 2/3] cacheinfo: Check cache properties are present in DT Message-ID: <20230404-hatred-swimmer-6fecdf33b57a@spud> References: <20230327115953.788244-1-pierre.gondois@arm.com> <20230327115953.788244-3-pierre.gondois@arm.com> MIME-Version: 1.0 In-Reply-To: <20230327115953.788244-3-pierre.gondois@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230404_122953_618572_F2FB6E31 X-CRM114-Status: GOOD ( 31.45 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: multipart/mixed; boundary="===============3106416138090285367==" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org --===============3106416138090285367== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="pi8T+o/24pYeiODx" Content-Disposition: inline --pi8T+o/24pYeiODx Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hey Pierre, On Mon, Mar 27, 2023 at 01:59:50PM +0200, Pierre Gondois wrote: > If a Device Tree (DT) is used, the presence of cache properties is > assumed. Not finding any is not considered. For arm64 platforms, > cache information can be fetched from the clidr_el1 register. > Checking whether cache information is available in the DT > allows to switch to using clidr_el1. >=20 > init_of_cache_level() > \-of_count_cache_leaves() > will assume there a 2 cache leaves (L1 data/instruction caches), which > can be different from clidr_el1 information. >=20 > cache_setup_of_node() tries to read cache properties in the DT. > If there are none, this is considered a success. Knowing no > information was available would allow to switch to using clidr_el1. > Alex reported seeing a bunch of messages in his boot log in QEMU since -rc1 which appears to be the fault of, as far as I can tell, e0df442ee49 ("cacheinfo: Check 'cache-unified' property to count cache leaves") like: cacheinfo: Unable to detect cache hierarchy for CPU N The RISC-V QEMU virt machine doesn't define any cache properties of any sort in the dtb, and unlike the arm64 virt machine I tried (a72) doesn't have some registers that cache info is discoverable from. When we call of_count_cache_leaves() from init_of_cache_level() and there are of course no reasons to increment leaves, we hit the return 2 case you mention above, setting num_leaves to 2. As you mention, when we hit cache_setup_of_node(), levels is not going to be set to one, so we trigger the condition (this_leaf->level !=3D 1) and, as there are no cache nodes, break out of the loop without incrementing index. Index is therefore less than 2, and thus we return -ENOENT. This is of course propagated back out to detect_cache_attributes() and triggers the "Unable to detect..." printout :( With this patch(set), the spurious error prints go away, but we are left with a "Early cacheinfo failed, ret =3D -22" which will need to be fixed. So I think this also needs to be: Fixes: de0df442ee49 ("cacheinfo: Check 'cache-unified' property to count ca= che leaves") Probably also needs a: Reported-by: Alexandre Ghiti since he's found an actual, rather than theoretical, problem! Cheers, Conor. > Signed-off-by: Pierre Gondois > --- > drivers/base/cacheinfo.c | 30 ++++++++++++++++++++++++++++++ > 1 file changed, 30 insertions(+) >=20 > diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c > index 4ca117574af1..5b0edf2d5da8 100644 > --- a/drivers/base/cacheinfo.c > +++ b/drivers/base/cacheinfo.c > @@ -78,6 +78,9 @@ bool last_level_cache_is_shared(unsigned int cpu_x, uns= igned int cpu_y) > } > =20 > #ifdef CONFIG_OF > + > +static bool of_check_cache_nodes(struct device_node *np); > + > /* OF properties to query for a given cache type */ > struct cache_type_info { > const char *size_prop; > @@ -205,6 +208,11 @@ static int cache_setup_of_node(unsigned int cpu) > return -ENOENT; > } > =20 > + if (!of_check_cache_nodes(np)) { > + of_node_put(np); > + return -ENOENT; > + } > + > prev =3D np; > =20 > while (index < cache_leaves(cpu)) { > @@ -229,6 +237,25 @@ static int cache_setup_of_node(unsigned int cpu) > return 0; > } > =20 > +static bool of_check_cache_nodes(struct device_node *np) > +{ > + struct device_node *next; > + > + if (of_property_read_bool(np, "cache-size") || > + of_property_read_bool(np, "i-cache-size") || > + of_property_read_bool(np, "d-cache-size") || > + of_property_read_bool(np, "cache-unified")) > + return true; > + > + next =3D of_find_next_cache_node(np); > + if (next) { > + of_node_put(next); > + return true; > + } > + > + return false; > +} > + > static int of_count_cache_leaves(struct device_node *np) > { > unsigned int leaves =3D 0; > @@ -260,6 +287,9 @@ int init_of_cache_level(unsigned int cpu) > struct device_node *prev =3D NULL; > unsigned int levels =3D 0, leaves, level; > =20 > + if (!of_check_cache_nodes(np)) > + goto err_out; > + > leaves =3D of_count_cache_leaves(np); > if (leaves > 0) > levels =3D 1; > --=20 > 2.25.1 >=20 --pi8T+o/24pYeiODx Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRh246EGq/8RLhDjO14tDGHoIJi0gUCZCx6qgAKCRB4tDGHoIJi 0lLFAQDaPIa1OUdhPwmPtXU4arYYjYn97JNiEXAJOVtsGeJZnQEAzxGcMW6AYQD7 73njRu6NY//OIQjaCy+Cou8mFSM1pQ0= =Gepo -----END PGP SIGNATURE----- --pi8T+o/24pYeiODx-- --===============3106416138090285367== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel --===============3106416138090285367==--