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 2392FCA6019 for ; Fri, 9 Oct 2026 10:09:04 +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:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=XhKjlNMbTO0uP/eZkxb7YfCPIOitUMHa55FaD0BoXhE=; b=wXa5vZHQKxpvw0h43EIghjFZAi +3AqRU9dGOmuSn+aUsGTMz/arIiHeiBtXzbjb1vr5svzhTuLiCutVve1zdRrkZDDRW2cDIEZi7k1o O4V68DKptb8whQGvv4fALtRV3mWU2B1m7Y7AU7PYSw5F9+e2WTOJprm3KpKCNFUMhX+82T1AKNdT3 FKZAAAgsuN3Pyaya6NDMOoiJunftQlPHHf/BLOViSN123H8CXWyMEDMnt/15RQjvpUT2TqI6rnyx1 O3RI5lMm5xKstslXc7Ni3bWCWjRJ8jbOZO+66lGXhDoG+VqZBVnwLXrZfVKbUaHjjNaj5IfQLQrD+ 8Vlms1vg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xF7X7-00000005znJ-1unE; Fri, 09 Oct 2026 10:08:57 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1xF7X6-00000005zlr-03Ob for linux-arm-kernel@lists.infradead.org; Fri, 09 Oct 2026 10:08:56 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id C083940DA4; Fri, 9 Oct 2026 10:08:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 720EE1F00898; Fri, 9 Oct 2026 10:08:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791540535; bh=XhKjlNMbTO0uP/eZkxb7YfCPIOitUMHa55FaD0BoXhE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=gdCh8m9dXXKFl/gO4wrhxz4vNsUAqUmoCWwjnjYu9K8XGVuUelgKUV3dLbfiveiZx ANzgLmDl6kCcxta8WMdcdt6fC8LWeaN1lbmyXTXLgWkFtP1TKpW2gwI2kNWb0VajIY n+OrbsjNSvT6ABUVRLsjsUqOKMLVEnYDpfWiLMM7cInG5joTF90rkYQ2eUWbZRaVjR cqtE0SKdSP8QrZnfyNdwjXY1EEv4LMItJA5Pbnb+qJKR2nrRvbyt2YAgB7i5OclHYa bxmIM3M56MXnGel7KCXgyWOfoHyxZ1FukuEyb0PTPYcj6+ByYXtw6OhDdikA63VSEH AxEtlP0mKF/dg== From: Will Deacon To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, Will Deacon , Thomas Gleixner , Ben Horgan , =?UTF-8?q?=C8=98tefania=20Ion?= , Catalin Marinas , Pankaj Patil , Borislav Petkov , Lorenzo Pieralisi , Jinjie Ruan , Mark Rutland , Tarun Sahu , Fuad Tabba , David Woodhouse , Peter Zijlstra , Marc Zyngier Subject: [PATCH v2 18/23] firmware/psci: Cache PSCI v0.2+ version number to avoid redundant SMCs Date: Fri, 9 Oct 2026 11:07:29 +0100 Message-ID: <20261009100738.31288-19-will@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20261009100738.31288-1-will@kernel.org> References: <20261009100738.31288-1-will@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 Secure monitor calls to EL3 aren't necessarily cheap, so cache the PSCI version number in memory to avoid asking firmware the same question over and over again. Reviewed-by: Jinjie Ruan Signed-off-by: Will Deacon --- drivers/firmware/psci/psci.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c index e73bae6cb23a..8bb3f7c37678 100644 --- a/drivers/firmware/psci/psci.c +++ b/drivers/firmware/psci/psci.c @@ -155,7 +155,12 @@ static u32 psci_0_1_get_version(void) static u32 psci_0_2_get_version(void) { - return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0); + static u32 version; + + if (unlikely(!version)) + version = invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0); + + return version; } int psci_set_osi_mode(bool enable) -- 2.56.0.385.gd3acb90ef8-goog