From nobody Thu Oct 2 10:55:41 2025 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id CD5F530506D for ; Thu, 18 Sep 2025 12:56:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758200196; cv=none; b=LZfw5DDAxfRPm29hMxsUxKXUlke9n0qNYgY1PnOCF31dORHYTGeKwpsVqGtjBPsoVAe2nNKziuZnwZZfQrfwxP65LiipDa/jRaXgSrhhZJvCqWvoDujDpsVCIOiCE4IfS9NiIphvFoNY7KK1MgZ4FVOnON286fJrTaUivdR0rHI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758200196; c=relaxed/simple; bh=2u1rVz+L33xuk2tuSWHg8OaS3eVnMWm7T+p+EPdK3Ug=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=lZDkk03J3+5wReutLGgjMFh4hANr2jSP2ho6kxiCpZfP7cFLO3e90X1P0l7uxir4/gnpGxh/E6UnG/JOj3vL5sAhunTLkNKKdFVlV4FENHpRI+Lwb+4xufJjR9LsxMrlVbNqSe6z0E9bF+S7ByMQaCab76TjJjnioJI59SswyBg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 167E61AED; Thu, 18 Sep 2025 05:56:25 -0700 (PDT) Received: from ewhatever.cambridge.arm.com (ewhatever.cambridge.arm.com [10.1.197.1]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id E20AB3F66E; Thu, 18 Sep 2025 05:56:31 -0700 (PDT) From: Suzuki K Poulose To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev, catalin.marinas@arm.com, will@kernel.org, gshan@redhat.com, aneesh.kumar@kernel.org, sami.mujawar@arm.com, sudeep.holla@arm.com, steven.price@arm.com, Suzuki K Poulose Subject: [PATCH v3 3/3] arm64: acpi: Enable ACPI CCEL support Date: Thu, 18 Sep 2025 13:56:18 +0100 Message-ID: <20250918125618.2125733-4-suzuki.poulose@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250918125618.2125733-1-suzuki.poulose@arm.com> References: <20250918125618.2125733-1-suzuki.poulose@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add support for ACPI CCEL by handling the EfiACPIMemoryNVS type memory. As per UEFI specifications NVS memory is reserved for Firmware use even after exiting boot services. Thus map the region as read-only. Cc: Sami Mujawar Cc: Will Deacon Cc: Catalin Marinas Cc: Aneesh Kumar K.V Cc: Steven Price Cc: Sudeep Holla Cc: Gavin Shan Reviewed-by: Gavin Shan Tested-by: Sami Mujawar Signed-off-by: Suzuki K Poulose --- arch/arm64/kernel/acpi.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c index 4d529ff7ba51..b3195b3b895f 100644 --- a/arch/arm64/kernel/acpi.c +++ b/arch/arm64/kernel/acpi.c @@ -357,6 +357,16 @@ void __iomem *acpi_os_ioremap(acpi_physical_address ph= ys, acpi_size size) * as long as we take care not to create a writable * mapping for executable code. */ + fallthrough; + + case EFI_ACPI_MEMORY_NVS: + /* + * ACPI NVS marks an area reserved for use by the + * firmware, even after exiting the boot service. + * This may be used by the firmware for sharing dynamic + * tables/data (e.g., ACPI CCEL) with the OS. Map it + * as read-only. + */ prot =3D PAGE_KERNEL_RO; break; =20 --=20 2.43.0