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 9E0ABC54F54 for ; Fri, 31 Jul 2026 15:13:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: 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=MTV8+yiU3k6de+WXb2mc3kleT5uKD/pTgFM6tA8U944=; b=DpT3O7xhNStlImXm/I9qPlTYLb MgyoSJEr0886fLBJOsTGfGxwWNnqA1ybN0K42ZmcTv9LCgqT/ZWer/Ue0ljC5/G1tqyTT8xYTf+jZ ovU7ATdWAIGdmon9jOArwjDJX8Om8YSsRHBU17tPJmVyUNq1rsZZaLbqpgaWM2aRr15nxRVXBbnDK 7YKEeIuKno9D1qDHtLRQIe/bFSd4evuFg2ljVBlpZmGGSdZOMXT3Vq+u+DTZoQqCguYfw6MXpwex3 aEOSk97WM4ISUqfEYSxhtvzWTulm6l4t4Bl3uOwECI2QPLNQH63ZpzeLSpTTLornJCoyX6QM1uXP9 oJpppIhw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wpovQ-0000000Csf8-1Ihe; Fri, 31 Jul 2026 15:13:28 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wpovO-0000000Csea-1zXc for linux-arm-kernel@lists.infradead.org; Fri, 31 Jul 2026 15:13:26 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 8154D6004E; Fri, 31 Jul 2026 15:13:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D60F21F000E9; Fri, 31 Jul 2026 15:13:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785510805; bh=MTV8+yiU3k6de+WXb2mc3kleT5uKD/pTgFM6tA8U944=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=HxP/lZcOvqnIe4XpjhtStBYWqaYQt6Y3gGgUIo5MSchImNpRdjJiq647xJ9Bm1fQe wZwB97DxcT/x2LqDiRkFzzd7mCXIE1zcD3ZIQVgHfOLQKtK/R3R/eRTByRvM06K0f6 Z+BotDBFfnogB147dv4WBKlWTudpymSgZXBCZ2q3chljlWjkGdyk7lnRyDpLXPVaC4 wainOZ6tHOCQnCM7iKE0XGVHraLbCcQIdlY/q8P8E6+iLVqUVzwR54QgwSrtse35O+ otxVUJE1lbqGrHAgk+0SJxnVuxVbimCC6b0KcEBU3ybTKO2YVWEou/0xjKt9u5/s7H Xnsp+Qi9W1L5A== Date: Fri, 31 Jul 2026 16:13:20 +0100 From: Will Deacon To: Linu Cherian Cc: Catalin Marinas , Ryan Roberts , Kevin Brodsky , Anshuman Khandual , Suzuki K Poulose , Mark Rutland , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Gavin Shan Subject: Re: [PATCH v4 6/6] arm64: cpufeature: Detect BBML3 based on ID_AA64MMFR2_EL1.BBM Message-ID: References: <20260723044034.2983651-1-linu.cherian@arm.com> <20260723044034.2983651-7-linu.cherian@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260723044034.2983651-7-linu.cherian@arm.com> 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Jul 23, 2026 at 10:10:33AM +0530, Linu Cherian wrote: > Add ID_AA64MMFR2_EL1.BBM based BBML3 feature detection in > cpu_supports_bbml3() so that cpus with the feature would > not have to be added into MIDR based supports_bbml3_list. > > Reviewed-by: Gavin Shan > Reviewed-by: Anshuman Khandual > Signed-off-by: Linu Cherian > --- > arch/arm64/kernel/cpufeature.c | 17 +++++++++-------- > 1 file changed, 9 insertions(+), 8 deletions(-) > > diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c > index 896bafdb00b1..dbd7d187520c 100644 > --- a/arch/arm64/kernel/cpufeature.c > +++ b/arch/arm64/kernel/cpufeature.c > @@ -2133,6 +2133,12 @@ static bool hvhe_possible(const struct arm64_cpu_capabilities *entry, > > bool cpu_supports_bbml3(void) > { > + u64 mmfr2; > + > + mmfr2 = __read_sysreg_by_encoding(SYS_ID_AA64MMFR2_EL1); > + if (SYS_FIELD_GET(ID_AA64MMFR2_EL1, BBM, mmfr2) >= ID_AA64MMFR2_EL1_BBM_3) > + return true; This is a bit of a nit, but I think it would be more consistent to use has_cpuid_feature() here instead of __read_sysreg_by_encoding(), similarly to how we handle kpti in unmap_kernel_at_el0() (which also has both an ID register field and a list of MIDRs). Will