From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 ECA8A2918F6 for ; Thu, 24 Apr 2025 19:53:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745524437; cv=none; b=LA7C1MUX0nocfvaXP4xD9ETJmBgonRWf3ATk69k75Gr4NkZDsaqwzvjpb/pCoSuiqUfumv7P7x0HcO4rtAHhMaH/FdxJ2LPmsD13uEf/GMY/LJ/bd8IAnZTSGFo6lfDQRJhcuhoDD5cavj8CuSzYip4yVva+4Ez4Qq9OZlh1M6o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745524437; c=relaxed/simple; bh=DNuxbwxEeFug/FXNMVi+tNl0Z2xT6Mw5Dv5Mh+OaEE8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=pMJwtbpzNyCXMn9Oz72co1tC/NDfgddVjJ52/7H+4izNIXH2yuiVkTCZhpWCredhQXdtUJpXhWl5tAWolu4N1dbDIlRAs4fDrWnwR0jJfLDkjNvRRmXvgvUlCLASGWBFtUmbT5OPIjrKtOcTWKofmnT3vvVjGZN6amZgzXDdMKI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=JstsVFhM; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="JstsVFhM" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1745524434; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=iU/3VyFMOfD63tP5kzXYfWr/+peX2XaMqzrC6eK+CtI=; b=JstsVFhMpZZ9a+3Q5A5Arw0eyWA0QbSg9NYc6dYS4CQafBnp7I+JivXdw0FMtaaUY8j8fX dfFDLEqEmhDmmTBo5N6IA+FIODX4XN+/c5QcBLrFqLpcT1LdEzD49dwq5EUq0nq+IgCnBl LRvh8d8B6rvJRd2h3BnFTjKU0xyMQeY= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-641-DyQdFEH0Oo6vg5QkMrlHNg-1; Thu, 24 Apr 2025 15:53:49 -0400 X-MC-Unique: DyQdFEH0Oo6vg5QkMrlHNg-1 X-Mimecast-MFC-AGG-ID: DyQdFEH0Oo6vg5QkMrlHNg_1745524427 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id DE43C1956086; Thu, 24 Apr 2025 19:53:46 +0000 (UTC) Received: from [10.44.32.28] (unknown [10.44.32.28]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 59D5530001A2; Thu, 24 Apr 2025 19:53:41 +0000 (UTC) Message-ID: Date: Thu, 24 Apr 2025 21:53:39 +0200 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 net-next v4 5/8] mfd: zl3073x: Add functions to work with register mailboxes To: Andrew Lunn Cc: netdev@vger.kernel.org, Vadim Fedorenko , Arkadiusz Kubalewski , Jiri Pirko , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Prathosh Satish , Lee Jones , Kees Cook , Andy Shevchenko , Andrew Morton , Michal Schmidt , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org References: <20250424154722.534284-1-ivecera@redhat.com> <20250424154722.534284-6-ivecera@redhat.com> <5094e051-5504-48a5-b411-ed1a0d949eeb@lunn.ch> <8082254c-01a6-4aca-84de-76083fdcbb3b@lunn.ch> Content-Language: en-US From: Ivan Vecera In-Reply-To: <8082254c-01a6-4aca-84de-76083fdcbb3b@lunn.ch> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 On 24. 04. 25 9:18 odp., Andrew Lunn wrote: >> During taking 613cbb91e9ce ("media: Add MIPI CCI register access helper >> functions") approach I found they are using for these functions u64 >> regardless of register size... Just to accommodate the biggest >> possible value. I know about weakness of 'void *' usage but u64 is not >> also ideal as the caller is forced to pass always 8 bytes for reading >> and forced to reserve 8 bytes for each read value on stack. > > In this device, how are the u48s used? Are they actually u48s, or are > they just u8[6], for example a MAC address? The network stack has lots > of functions like: > > eth_hw_addr_set(struct net_device *dev, const u8 *addr) u48 registers always represent 48bit integer... they read from device using bulk read as big-endian 48bit int. The same is valid also for u16 and u32. Ivan