From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8ABC15221E9 for ; Mon, 7 Sep 2026 16:41:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788799277; cv=none; b=DAnMO9/Qq7wz4x/zrw71yjDZNcScX0Nllh+f0MR7nOkjLLJX9DtKGcbY68mutSS0yguz49HcVo6Sy8sYrIZA0uG9Fpyr9zO4QnscngEJ2ixzexSB4Stp02Y/qq5KruUFQVpsiVN2mlE1rNL9DT1Lv1g9oN9Jc3z2ddiQ8WladA0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788799277; c=relaxed/simple; bh=FXk4Y6n0MApbau7HM+JsM6nsUK9vl07kcs2O3VY89uw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=qDERnOaG/kCIm5eDae/IBsNBb2G5apJ67GiKDB/vObqHH8J/9gNW8gZXknKPemKguneftzTDfhyb8yQxsFwmvR3iW00zysFUf5wmm0+P5lJz1HSP1p9EhDgYAryqmaQL7LFF95uOEy0vHl6Wtk/v/wy2DCZAYTJcVOqpGBpbMRk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ks4cUze2; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ks4cUze2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1905A1F00A3A; Mon, 7 Sep 2026 16:41:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788799275; bh=l1KlFUrFQByY5HMeuJRtMe8QamhdpHtavT/1/TB6eNY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ks4cUze2H8K/HkyakRaX2J/XJEk4oNPa0foT0KVPO870JyklkD4Fkepd0rVYr5erv bN1hQ7DGY3rRb508vdki6oZIUyHNU6T9CHyWOa3zN0tMhSPx+aJnsLlV+NvKsCOe72 NH7fmblAs/qhx5wOmpf6bXdNMNx8mHDG6A3AfMFQF/GboxoT99sZ6g1FLiokIksELx gbBtceCZpvXhVbhgdECaWNTXqxtpvL0PRQRHFBQ0v+GB+Vl7iaYVIJFfw7pHB7is0x MGw/v4Qhrr/DMYZEMuehtuyEeMygp1ksSBTOAPMx1jV1sKrMXXfS3VqgtUtHril+xu YYKPqPifTqAJQ== From: Will Deacon To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, Will Deacon , Thomas Gleixner , Catalin Marinas , Borislav Petkov , Lorenzo Pieralisi , Jinjie Ruan , Mark Rutland , David Woodhouse , Peter Zijlstra , Marc Zyngier Subject: [PATCH 14/19] firmware/psci: Cache PSCI v0.2+ version number to avoid redundant SMCs Date: Mon, 7 Sep 2026 17:40:17 +0100 Message-ID: <20260907164024.17164-15-will@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260907164024.17164-1-will@kernel.org> References: <20260907164024.17164-1-will@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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. 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) -- 2.55.0.979.g7e5102b832-goog