From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751169AbdAPJqF (ORCPT ); Mon, 16 Jan 2017 04:46:05 -0500 Received: from mga06.intel.com ([134.134.136.31]:10578 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750919AbdAPJqD (ORCPT ); Mon, 16 Jan 2017 04:46:03 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.33,238,1477983600"; d="scan'208";a="53511066" Date: Mon, 16 Jan 2017 11:45:59 +0200 From: Jarkko Sakkinen To: James Bottomley Cc: Jason Gunthorpe , open list , linux-security-module@vger.kernel.org, tpmdd-devel@lists.sourceforge.net Subject: Re: [tpmdd-devel] [PATCH RFC v2 5/5] tpm2: expose resource manager via a device link /dev/tpms Message-ID: <20170116094559.jsw7ffrozs42ubue@intel.com> References: <20170112174612.9314-1-jarkko.sakkinen@linux.intel.com> <20170112174612.9314-6-jarkko.sakkinen@linux.intel.com> <20170112205628.qh3yf2jcargtw6qv@intel.com> <20170113172537.GA31125@obsidianresearch.com> <1484329208.2527.18.camel@HansenPartnership.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1484329208.2527.18.camel@HansenPartnership.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.6.2-neo (2016-08-21) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 13, 2017 at 09:40:08AM -0800, James Bottomley wrote: > On Fri, 2017-01-13 at 10:25 -0700, Jason Gunthorpe wrote: > > On Thu, Jan 12, 2017 at 10:56:28PM +0200, Jarkko Sakkinen wrote: > > > > > > dev_t tpm_devt; > > > > > > But they should have different major device numbers. > > > > major/minors don't really matter these days since they are dynamic > > Right, although we have this weird piece of code: > > > if (chip->dev_num == 0) > chip->dev.devt = MKDEV(MISC_MAJOR, TPM_MINOR); > else > chip->dev.devt = MKDEV(MAJOR(tpm_devt), chip->dev_num); > > So the first TPM device gets the MISC_MAJOR with TPM_MINOR and the rest > get the dynamic major/minor. It means when you do an ls on a complex > system you get something like: > > crw------- 1 root root 10, 224 Jan 13 06:21 /dev/tpm0 > crw------- 1 root root 246, 1 Jan 13 09:38 /dev/tpm1 > crw-rw-rw- 1 root root 246, 65536 Jan 13 06:21 /dev/tpms0 > crw-rw-rw- 1 root root 246, 65537 Jan 13 09:38 /dev/tpms1 > > Perhaps it's time just to junk the reserved misc minor? +1 And Jason is correct about major numbers. I still am puzzled whether these should share the device class and devt with raw /dev/tpm0. /Jarkko