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 76515E706FA for ; Thu, 21 Sep 2023 09:14:10 +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: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=pJ0+4xbOHTPPoCFEeD9iK8YbphsEJdET5bOFxvJT1ik=; b=uJMafOZ8wThKoB vTZtodm2ogDIoClKQeVxEcW7sOZ1EKTe09m6eja4vUnQZyi88014YkDa11hHTP86epKoxFk8ND7Jc j9uENTuh9JfyTkzPi2JKCiLNO6xEVmwOVmRP2/KypsAYRFL3GTxwjQslyu+wdFyMVLojzgFTBTW1P hn19IMT+0nsKXcR1Ca5u4zN/LNdfDaMWOu/4HSpdO3027o9CSi4yrUzxvK3n+i8geg6U0mgURUPEy dfIrwedVmnG6mtJ8uN7zyh23BaJSrgI976f8L4Nnkq1u54Y4ZhGmEPFQuiZws7+Sq7rs2rJ13mwvV flopcKmfahRZzd45VtqQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qjFkk-005Yxg-1G; Thu, 21 Sep 2023 09:13:42 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qjFkg-005YwD-2E for linux-arm-kernel@lists.infradead.org; Thu, 21 Sep 2023 09:13:40 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2DB3B14BF; Thu, 21 Sep 2023 02:14:12 -0700 (PDT) Received: from [10.1.197.1] (ewhatever.cambridge.arm.com [10.1.197.1]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0E82A3F59C; Thu, 21 Sep 2023 02:13:32 -0700 (PDT) Message-ID: <55c9f428-b715-a2ae-5b89-d125a0104ea3@arm.com> Date: Thu, 21 Sep 2023 10:13:31 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Subject: Re: [PATCH 05/37] arm64: Add cpus_have_final_boot_cap() Content-Language: en-US To: Mark Rutland , linux-arm-kernel@lists.infradead.org Cc: ardb@kernel.org, bertrand.marquis@arm.com, boris.ostrovsky@oracle.com, broonie@kernel.org, catalin.marinas@arm.com, daniel.lezcano@linaro.org, james.morse@arm.com, jgross@suse.com, maz@kernel.org, oliver.upton@linux.dev, pcc@google.com, sstabellini@kernel.org, tglx@linutronix.de, vladimir.murzin@arm.com, will@kernel.org References: <20230919092850.1940729-1-mark.rutland@arm.com> <20230919092850.1940729-6-mark.rutland@arm.com> From: Suzuki K Poulose In-Reply-To: <20230919092850.1940729-6-mark.rutland@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230921_021338_820412_995A524F X-CRM114-Status: GOOD ( 25.44 ) 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-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Mark On 19/09/2023 10:28, Mark Rutland wrote: > The cpus_have_final_boot_cap() function can be used to test a cpucap nit: cpus_have_final_cap() > while also verifying that we do not consume the cpucap until system > capabilities have been finalized. It would be helpful if we could do > likewise for boot cpucaps. > > This patch adds a new cpus_have_final_boot_cap() helper which can be > used to test a cpucap while also verifying that boot capabilities have > been finalized. Users will be added in subsequent patches. > > Signed-off-by: Mark Rutland > Cc: Catalin Marinas > Cc: Mark Brown > Cc: Suzuki K Poulose > Cc: Will Deacon > --- > arch/arm64/include/asm/cpufeature.h | 27 +++++++++++++++++++++++++-- > 1 file changed, 25 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h > index 7d5317bc2429f..e832b86c6b57f 100644 > --- a/arch/arm64/include/asm/cpufeature.h > +++ b/arch/arm64/include/asm/cpufeature.h > @@ -438,6 +438,11 @@ unsigned long cpu_get_elf_hwcap2(void); > #define cpu_set_named_feature(name) cpu_set_feature(cpu_feature(name)) > #define cpu_have_named_feature(name) cpu_have_feature(cpu_feature(name)) > > +static __always_inline bool boot_capabilities_finalized(void) > +{ > + return alternative_has_cap_likely(ARM64_ALWAYS_BOOT); > +} > + > static __always_inline bool system_capabilities_finalized(void) > { > return alternative_has_cap_likely(ARM64_ALWAYS_SYSTEM); > @@ -473,8 +478,26 @@ static __always_inline bool __cpus_have_const_cap(int num) > /* > * Test for a capability without a runtime check. > * > - * Before capabilities are finalized, this will BUG(). > - * After capabilities are finalized, this is patched to avoid a runtime check. > + * Before boot capabilities are finalized, this will BUG(). > + * After boot capabilities are finalized, this is patched to avoid a runtime > + * check. > + * > + * @num must be a compile-time constant. > + */ > +static __always_inline bool cpus_have_final_boot_cap(int num) > +{ > + if (boot_capabilities_finalized()) Does this need to make sure the cap is really a "BOOT" cap ? It is a bit of an overkill, but prevents users from incorrectly assuming the cap is finalised ? Suzuki > + return __cpus_have_const_cap(num); > + else > + BUG(); > +} > + > +/* > + * Test for a capability without a runtime check. > + * > + * Before system capabilities are finalized, this will BUG(). > + * After system capabilities are finalized, this is patched to avoid a runtime > + * check. > * > * @num must be a compile-time constant. > */ _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel