From patchwork Thu Jan 17 20:33:21 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Martin X-Patchwork-Id: 10768983 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0631313BF for ; Thu, 17 Jan 2019 20:37:18 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E9E5B2DDEE for ; Thu, 17 Jan 2019 20:37:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DE4512E978; Thu, 17 Jan 2019 20:37:17 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id A85432DDEE for ; Thu, 17 Jan 2019 20:37:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=7hwO/EwmhvpOy8bmowQjPndnTIypqRV25fqOXxyFbhw=; b=NKL07WOVfoi/aK77jJ2KOnUud9 jXuO0l8pgzfv9c90FZIoOufrqmXu2y9OQnQGo+3WZttrkCVl6e0b27vtXmD8ZkE4tv3RazPD9DWrI bkZfEFMJc2BqbDCCR0TIAN1oFiRza3jNQqlKWLZdw5DtzJSii1aMO7Ikka6RMNs0iGt+Z023M1wiP m0/Z9bfh1Ifee9c0L0iTHZZyzzdt1wEZP24yzAWx6Spfa/O3ggdIdiHAU5eokb4a+iuOMv6JG6aPO +vkde3soSFsWJ2ZFh9x1IVgwaOL9cZJIo/xCqGH9FynCP5F8/Fo5na/GlRB3UdmHlAFM6Zc1FP7uK eMGb6EQQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gkEPH-00039r-CE; Thu, 17 Jan 2019 20:36:55 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gkENA-00005L-R9 for linux-arm-kernel@lists.infradead.org; Thu, 17 Jan 2019 20:34:48 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4658C1596; Thu, 17 Jan 2019 12:34:44 -0800 (PST) Received: from e103592.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 4D4CD3F819; Thu, 17 Jan 2019 12:34:42 -0800 (PST) From: Dave Martin To: kvmarm@lists.cs.columbia.edu Subject: [PATCH v4 07/25] arm64/sve: Clarify role of the VQ map maintenance functions Date: Thu, 17 Jan 2019 20:33:21 +0000 Message-Id: <1547757219-19439-8-git-send-email-Dave.Martin@arm.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1547757219-19439-1-git-send-email-Dave.Martin@arm.com> References: <1547757219-19439-1-git-send-email-Dave.Martin@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190117_123445_449358_860942C6 X-CRM114-Status: GOOD ( 13.48 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , Okamoto Takayuki , Christoffer Dall , Ard Biesheuvel , Marc Zyngier , Catalin Marinas , Will Deacon , Julien Grall , =?utf-8?q?Alex_Benn=C3=A9e?= , linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP The roles of sve_init_vq_map(), sve_update_vq_map() and sve_verify_vq_map() are highly non-obvious to anyone who has not dug through cpufeatures.c in detail. Since the way these functions interact with each other is more important here than a full understanding of the cpufeatures code, this patch adds comments to make the functions' roles clearer. No functional change. Signed-off-by: Dave Martin --- arch/arm64/kernel/fpsimd.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 64729e2..92c2331 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -647,6 +647,10 @@ static void sve_probe_vqs(DECLARE_BITMAP(map, SVE_VQ_MAX)) } } +/* + * Initialise the set of known supported VQs for the boot CPU. + * This is called during kernel boot, before secondary CPUs are brought up. + */ void __init sve_init_vq_map(void) { sve_probe_vqs(sve_vq_map); @@ -656,6 +660,7 @@ void __init sve_init_vq_map(void) /* * If we haven't committed to the set of supported VQs yet, filter out * those not supported by the current CPU. + * This function is called during the bring-up of early secondary CPUs only. */ void sve_update_vq_map(void) { @@ -666,7 +671,10 @@ void sve_update_vq_map(void) bitmap_or(sve_vq_partial_map, sve_vq_partial_map, tmp_map, SVE_VQ_MAX); } -/* Check whether the current CPU supports all VQs in the committed set */ +/* + * Check whether the current CPU supports all VQs in the committed set. + * This function is called during the bring-up of late secondary CPUs only. + */ int sve_verify_vq_map(void) { DECLARE_BITMAP(tmp_map, SVE_VQ_MAX);