From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 0B5FC533D6 for ; Tue, 15 Jul 2025 14:38:43 +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=1752590326; cv=none; b=azibnDNGPzEWHvSSRVhCwTZAnbkSWFyBZ/HvCYhE8mtbDPPxYyHbZ1nZWpP13mnuRPVVmczbtik41nyScjjiSIta6lrRtxuP6PWo3P2h6Gtjm6z5lbaLtXZf6ZlZQQ6MpzzQR3qQ9D+T0XH7jk0Vq13iVZDcoLM+WkrGVC5xwSk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752590326; c=relaxed/simple; bh=P3j1E9KS66ASSlCoDWZJbpV0GTjtVplMundCobaQwhU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=cd7/sZ9XzXjJOw+4jAVIjCHp+gHbZ5D/vCSYD/CH+dM59X05+2phTWxtFIauZRTwAL54OVk1a728Tl5dKy7aElMoqqXsoFpn1IVwH/Iu0vP95IQm/BJvRiiPmKuOCWB28lgxeLtqVPrKp7zQNPrHuRu7Xe5A4WSJs93GxnXhzfM= 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 6B38112FC; Tue, 15 Jul 2025 07:38:34 -0700 (PDT) Received: from [10.57.0.241] (unknown [10.57.0.241]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id D52943F694; Tue, 15 Jul 2025 07:38:41 -0700 (PDT) Message-ID: Date: Tue, 15 Jul 2025 15:38:41 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 3/3] arm64: acpi: Enable ACPI CCEL support Content-Language: en-GB To: Will Deacon Cc: linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com, sami.mujawar@arm.com, aneesh.kumar@kernel.org, steven.price@arm.com, linux-kernel@vger.kernel.org, sudeep.holla@arm.com References: <20250613111153.1548928-1-suzuki.poulose@arm.com> <20250613111153.1548928-4-suzuki.poulose@arm.com> From: Suzuki K Poulose In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 15/07/2025 14:56, Will Deacon wrote: > On Fri, Jun 13, 2025 at 12:11:53PM +0100, Suzuki K Poulose wrote: >> ACPI CCEL memory area is reported as Non-Volatile storage area. Map it as >> PAGE_KERNEL. > > It would be helpful to have a citation for that. I've tried digging it > out of the ACPI spec, but that pointed me to the Intel TDX site and I > got lost in whitepapers :/ > https://uefi.org/specs/ACPI/6.5/05_ACPI_Software_Programming_Model.html#cc-event-log-acpi-table >> Cc: Sami Mujawar >> Cc: Will Deacon >> Cc: Catalin Marinas >> Cc: "Aneesh Kumar K.V" >> Cc: Steven Price >> Cc: Sudeep Holla >> Signed-off-by: Suzuki K Poulose >> --- >> arch/arm64/kernel/acpi.c | 5 +++++ >> 1 file changed, 5 insertions(+) >> >> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c >> index b9a66fc146c9..f52439d411a0 100644 >> --- a/arch/arm64/kernel/acpi.c >> +++ b/arch/arm64/kernel/acpi.c >> @@ -356,6 +356,11 @@ void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size) >> prot = PAGE_KERNEL_RO; >> break; >> >> + case EFI_ACPI_MEMORY_NVS: >> + /* Non-volatile storage, required for CCEL */ >> + prot = PAGE_KERNEL; > > By "storage" you just mean memory, right? Yep, it is just memory. I will drop the "NV storage" and simply mention, CCEL. Thanks! Suzuki > > Will