From nobody Wed Sep 10 06:02:23 2025 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 597302EF66C for ; Mon, 8 Sep 2025 22:35:38 +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=1757370939; cv=none; b=Rb8R4NGHLVUD0HkmXgPkdcLKpGKgSD5vs3ArOxcjt+jIzBNMqIihrhVLyZNUkTe6AB69BGDD36RSRMUH1INjYdgaC/lCukPplrXEqN3V6JjJE+3uHMnRvDCpQrpREz5qPbbfm4CEl0BZR2HUQ24E4z4jgWt0mgYSX+cU26ZW+KY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757370939; c=relaxed/simple; bh=rbvboZZ1ZVqBG/4LKcVh3kB2RdRKMoUZ2A70CphpX+4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VHdAYqUnKmrCtqUctOmOYHBXAthjoU2iYCVJYi8SDLXo27SntdXjKxNHCOvdXSX0G+4FChsk1ccbYHunUi6GpBrD82UoaKe5Wf7OH2fUUQoZeIlK59+UpoBCPwDl/uLQqnx7jhjq8dYwd7Muo6Rl5o3bTaTPkbbNwIGnsYRKRQw= 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 5C3D33024; Mon, 8 Sep 2025 15:35:29 -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 57A583F694; Mon, 8 Sep 2025 15:35:36 -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 v2 3/3] arm64: acpi: Enable ACPI CCEL support Date: Mon, 8 Sep 2025 23:35:19 +0100 Message-ID: <20250908223519.1759020-4-suzuki.poulose@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250908223519.1759020-1-suzuki.poulose@arm.com> References: <20250908223519.1759020-1-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 Signed-off-by: Suzuki K Poulose --- Changes since v1 - Map NVS region as read-only, update comment to clarify that the region is reserved for firmware use. --- arch/arm64/kernel/acpi.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c index 4d529ff7ba51..93b70f48a51f 100644 --- a/arch/arm64/kernel/acpi.c +++ b/arch/arm64/kernel/acpi.c @@ -360,6 +360,17 @@ void __iomem *acpi_os_ioremap(acpi_physical_address ph= ys, acpi_size size) prot =3D PAGE_KERNEL_RO; break; =20 + 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; + case EFI_ACPI_RECLAIM_MEMORY: /* * ACPI reclaim memory is used to pass firmware tables --=20 2.43.0