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 B836AECAAA1 for ; Sun, 23 Oct 2022 19:39:14 +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-Transfer-Encoding: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-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=xXUAVaa03cs+ifanQTcBEUCR7DblJMmbGV5dbVx04fo=; b=gavdtC7CTWUc+p Gvw0ZCKPvLbVhMA5vsAyVLHtxImZ64R9zTwECT6Tf6kuJ9cTilwLNU56lXzJP9ugm0H7UFJeLzF6l l+EVwoRUW6VA6n6+R1NVnLYtkDtOYRD+0gcjvPYapNU1/acw3vEuSG8QIc35Z0x/aVKc4QfQNAnhE WrzDR9fwXHAhpUkCjkxLfjw95ckl+ZmwFA10bwVi1gqOTUD9zpeDqmgTHBv5W0JECHAgaIUHa+9JL cHpE6F/OgEpACz7eQ1wsLu5IOyMSUPRmuCqlbCBNB32kCU7PIAJd6u8TCvDr8fr2DkwJSsr1MTfN/ UDoZ3zAmq7mU/l8DFShw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1omgoL-00G6on-0f; Sun, 23 Oct 2022 19:39:05 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1omgoH-00G6o8-Fw for linux-riscv@lists.infradead.org; Sun, 23 Oct 2022 19:39:03 +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 B573760F2F; Sun, 23 Oct 2022 19:39:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 44B72C433C1; Sun, 23 Oct 2022 19:38:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1666553940; bh=Khb5EznL/sGHGMfedrbMVtSAYVDrKigrf3Ki15q8I8A=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=XCtXDdR+HWgOB/CN7FOk6qv7kLTX6EICljzUJIqfl0MWeL4LxguG+KVqmcAyV6KkF ePzvG4npvG0byabb6ztsUsQI6ZD/18aZ4vx/Nn5ZqH2P5RdaRjD07k3gVa5jQfvIvP bPMTms/FFGc9KS82DUrxewYRr1tw0CSrSIvbJkS8ubYF7REgwl5iF+0Vz1HCeoi+HV FanV8q08wtlj+iZ8xfKWqdNcHlBLonfVSUlWvnVXZEhq+tX8tOVu3NAk263fgBP4WQ Hz0bi4H/7QVCx7zwwdPPjhTcEmCaPWsCsoCRDqV7dIYeC1Yaekvd9yJuLsolTCaV2n 9ql9QlDvGYDXw== Date: Sun, 23 Oct 2022 20:38:55 +0100 From: Conor Dooley To: Andrew Jones Cc: linux-riscv@lists.infradead.org, Palmer Dabbelt , Paul Walmsley , Albert Ou , Conor Dooley , Heiko Stuebner , Anup Patel , Atish Patra Subject: Re: [PATCH 3/3] RISC-V: Ensure Zicbom has a valid block size Message-ID: References: <20221021105905.206385-1-ajones@ventanamicro.com> <20221021105905.206385-4-ajones@ventanamicro.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20221021105905.206385-4-ajones@ventanamicro.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221023_123901_673377_A14F7059 X-CRM114-Status: GOOD ( 24.90 ) X-BeenThere: linux-riscv@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: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Fri, Oct 21, 2022 at 12:59:05PM +0200, Andrew Jones wrote: > When a DT puts zicbom in the isa string, but does not provide a block > size, ALT_CMO_OP() will attempt to do cache operations on address > zero since the start address will be ANDed with zero. We can't simply > BUG() in riscv_init_cbom_blocksize() when we fail to find a block > size because the failure will happen before logging works, leaving > users to scratch their heads as to why the boot hung. Instead, ensure > Zicbom is disabled and output an error which will hopefully alert > people that the DT needs to be fixed. While at it, add a check that > the block size is a power-of-2 too. > > Signed-off-by: Andrew Jones > --- > arch/riscv/kernel/cpufeature.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c > index 220be7222129..a4430a77df53 100644 > --- a/arch/riscv/kernel/cpufeature.c > +++ b/arch/riscv/kernel/cpufeature.c > @@ -9,6 +9,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -70,6 +71,20 @@ EXPORT_SYMBOL_GPL(__riscv_isa_extension_available); > > static bool riscv_isa_extension_check(int id) > { > + switch (id) { > + case RISCV_ISA_EXT_ZICBOM: > + if (!riscv_cbom_block_size) { > + if (IS_ENABLED(CONFIG_RISCV_ISA_ZICBOM)) Maybe I've missed something... Why not check if !IS_ENABLED() & return false immediately rather than doing it inside the attribute checks? I'll be compiled out of zicbom is enabled, so not like the non-error patch will be penalised with an extra check. > + pr_err("cbom-block-size not found, cannot use Zicbom\n"); > + return false; > + } else if (!is_power_of_2(riscv_cbom_block_size)) { > + if (IS_ENABLED(CONFIG_RISCV_ISA_ZICBOM)) > + pr_err("cbom-block-size is not a power-of-2, cannot use Zicbom\n"); > + return false; > + } > + return true; > + } > + > return true; > } > > -- > 2.37.3 > > > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv