From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753116AbdCMMiJ convert rfc822-to-8bit (ORCPT ); Mon, 13 Mar 2017 08:38:09 -0400 Received: from mail5.windriver.com ([192.103.53.11]:36642 "EHLO mail5.wrs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753067AbdCMMiA (ORCPT ); Mon, 13 Mar 2017 08:38:00 -0400 From: "Li, Meng" To: Jarkko Sakkinen CC: "linux-kernel@vger.kernel.org" , "peterhuewe@gmx.de" , "tpmdd@selhorst.net" , "jgunthorpe@obsidianresearch.com" , "tpmdd-devel@lists.sourceforge.net" Subject: RE: [PATCH] tpm: Add sysfs interface to show TPM hardware version Thread-Topic: [PATCH] tpm: Add sysfs interface to show TPM hardware version Thread-Index: AQHSm+/J7D42V0GmsUm7ZxvImdCg9KGStLTw Date: Mon, 13 Mar 2017 12:37:30 +0000 Message-ID: <529F9A9100AE8045A7A5B5A00A39FBB83DE93249@ALA-MBC.corp.ad.wrs.com> References: <1489382517-9078-1-git-send-email-Meng.Li@windriver.com> <20170313114852.kmfequmchxi3jams@intel.com> In-Reply-To: <20170313114852.kmfequmchxi3jams@intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [128.224.162.192] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > -----Original Message----- > From: Jarkko Sakkinen [mailto:jarkko.sakkinen@linux.intel.com] > Sent: Monday, March 13, 2017 7:49 PM > To: Li, Meng > Cc: linux-kernel@vger.kernel.org; peterhuewe@gmx.de; > tpmdd@selhorst.net; jgunthorpe@obsidianresearch.com; tpmdd- > devel@lists.sourceforge.net > Subject: Re: [PATCH] tpm: Add sysfs interface to show TPM hardware > version > > On Mon, Mar 13, 2017 at 01:21:57PM +0800, Meng.Li@windriver.com wrote: > > From: Limeng > > > > So far, there is not a sysfs interface for user space code to check > > the TPM hardware version(TPM1.x or TPM2). So, add a file named > > description in /sys/class/tpm/tpmX/ to show it. > > > > Signed-off-by: Meng Li > > --- > > drivers/char/tpm/tpm-chip.c | 85 > +++++++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 85 insertions(+) > > > > diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c > > index c406343..da2cd69 100644 > > --- a/drivers/char/tpm/tpm-chip.c > > +++ b/drivers/char/tpm/tpm-chip.c > > tpm-sysfs.c Probably makes sense to rename legacy group there as tpm1_ Thanks for this advice. > > > @@ -36,6 +36,83 @@ > > dev_t tpm_devt; > > > > /** > > + * show_description - sysfs interface for checking current TPM hardware > version. > > + * @dev: pointer to tpm chip device > > + * @attr: unused > > + * @buf: char buffer to be filled with TPM hardware version info > > + * > > + * Provides sysfs interface for showing current TPM hardware version. > > + */ > > +static ssize_t show_description(struct device *dev, > > + struct device_attribute *attr, char *buf) > > family > > > +{ > > + struct tpm_chip *chip = (struct tpm_chip *)container_of(dev,struct > tpm_chip,dev); > > + int ret; > > + > > + if (chip->flags & TPM_CHIP_FLAG_TPM2) > > + ret = sprintf(buf, "TPM 2.0"); > > + else > > + ret = sprintf(buf, "TPM 1.x"); > > + > > + return ret; > > +} > > + > > +/** > > + * store_description - interface for manually setting data. > > + * @dev: unused > > + * @attr: unused > > + * @buf: unused > > + * @count: unused > > + * > > + * There is not any process in this function, reserve for feature. > > + */ > > +static ssize_t store_description(struct device *dev, struct > device_attribute *attr, > > + const char *buf, size_t count) > > +{ > > + return count; > > +} > > What is this?? > > > + > > +static struct device_attribute tpm_attrs[] = { > > + __ATTR(description, S_IRUGO | S_IWUSR, show_description, > > +store_description), }; > > + > > +/** > > + * tpm_create_sysfs - Create tpm sysfs interface. > > + * @dev: pointer to tpm chip device > > + * > > + * Create sysfs interface for checking current TPM hardware version. > > + */ > > +static int tpm_create_sysfs(struct device *dev) { > > + int r, t; > > + > > + for (t = 0; t < ARRAY_SIZE(tpm_attrs); t++) { > > + r = device_create_file(dev, &tpm_attrs[t]); > > + if (r) { > > + dev_err(dev, "failed to create sysfs file\n"); > > + return r; > > + } > > + } > > + > > + return 0; > > +} > > + > > +/** > > + * tpm_remove_sysfs - Remove tpm sysfs interface. > > + * @dev: pointer to tpm chip device > > + * > > + * Remove sysfs interface for checking current TPM hardware version. > > + */ > > +static void tpm_remove_sysfs(struct device *dev) { > > + int t; > > + > > + for (t = 0; t < ARRAY_SIZE(tpm_attrs); t++) { > > + device_remove_file(dev, &tpm_attrs[t]); > > + } > > +} > > + > > +/** > > * tpm_try_get_ops() - Get a ref to the tpm_chip > > * @chip: Chip to ref > > * > > @@ -363,6 +440,13 @@ int tpm_chip_register(struct tpm_chip *chip) > > return rc; > > } > > > > + rc = tpm_create_sysfs(&chip->dev); > > + if (rc) { > > + tpm_del_legacy_sysfs(chip); > > + tpm_chip_unregister(chip); > > + return rc; > > + } > > + > > return 0; > > } > > EXPORT_SYMBOL_GPL(tpm_chip_register); > > @@ -382,6 +466,7 @@ int tpm_chip_register(struct tpm_chip *chip) > > */ > > void tpm_chip_unregister(struct tpm_chip *chip) { > > + tpm_remove_sysfs(&chip->dev); > > tpm_del_legacy_sysfs(chip); > > tpm_bios_log_teardown(chip); > > tpm_del_char_device(chip); > > -- > > 1.7.9.5 > > You should put the attributes to chip->groups instead of racy creation of > them. Thanks for your advice. It is more reasonable in to chip->groups. Regards, Limeng > > /Jarkko