Re: [tpmdd-devel] [BUG, bisect, PATCH 04/10] tpm: move the PPI attributes to character device directory.

[Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>]

On Thu, Nov 05, 2015 at 11:22:55AM +0200, Jarkko Sakkinen wrote:
> On Wed, Nov 04, 2015 at 10:17:05AM -0800, Jeremiah Mahler wrote:
> > Jarkko, all,
> > 
> > On Fri, Oct 16, 2015 at 09:40:23PM +0300, Jarkko Sakkinen wrote:
> > > Moved PPI attributes to the character device directory. This aligns with
> > > the sysfs guidelines and makes them race free because they are created
> > > atomically with the character device as part of device_register().The
> > > character device and the sysfs attributes appear at the same time to the
> > > user space.
> > > 
> > > As part of this change we enable PPI attributes also for TPM 2.0
> > > devices. In order to retain backwards compatibility with TPM 1.x
> > > devices, a symlink is created to the platform device directory.
> > > 
> > > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> > > Reviewed-by: Jason Gunthorpe <jason.gunthorpe@obsidianresearch.com>
> > > Tested-by: Mimi Zohar <zohar@linux.vnet.ibm.com> (on TPM 1.2)
> > > Tested-by: Chris J Arges <chris.j.arges@canonical.com>
> > > Tested-by: Colin Ian King <colin.king@canonical.com>
> > > ---
> > >  drivers/char/tpm/tpm-chip.c | 24 ++++++++++++++++--------
> > >  drivers/char/tpm/tpm.h      | 17 ++++++-----------
> > >  drivers/char/tpm/tpm_ppi.c  | 34 +++++++++++-----------------------
> > >  3 files changed, 33 insertions(+), 42 deletions(-)
> > > 
> > > diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> > > index 1082d4b..f26b0ae 100644
> > > --- a/drivers/char/tpm/tpm-chip.c
> > > +++ b/drivers/char/tpm/tpm-chip.c
> > > @@ -119,6 +119,9 @@ struct tpm_chip *tpmm_chip_alloc(struct device *dev,
> > >  	chip->dev.class = tpm_class;
> > >  	chip->dev.release = tpm_dev_release;
> > >  	chip->dev.parent = chip->pdev;
> > > +#ifdef CONFIG_ACPI
> > > +	chip->dev.groups = chip->groups;
> > > +#endif
> > >  
> > >  	if (chip->dev_num == 0)
> > >  		chip->dev.devt = MKDEV(MISC_MAJOR, TPM_MINOR);
> > > @@ -182,12 +185,6 @@ static int tpm1_chip_register(struct tpm_chip *chip)
> > >  	if (rc)
> > >  		return rc;
> > >  
> > > -	rc = tpm_add_ppi(chip);
> > > -	if (rc) {
> > > -		tpm_sysfs_del_device(chip);
> > > -		return rc;
> > > -	}
> > > -
> > >  	chip->bios_dir = tpm_bios_log_setup(chip->devname);
> > >  
> > >  	return 0;
> > > @@ -201,8 +198,6 @@ static void tpm1_chip_unregister(struct tpm_chip *chip)
> > >  	if (chip->bios_dir)
> > >  		tpm_bios_log_teardown(chip->bios_dir);
> > >  
> > > -	tpm_remove_ppi(chip);
> > > -
> > >  	tpm_sysfs_del_device(chip);
> > >  }
> > >  
> > > @@ -225,10 +220,20 @@ int tpm_chip_register(struct tpm_chip *chip)
> > >  	if (rc)
> > >  		return rc;
> > >  
> > > +	tpm_add_ppi(chip);
> > > +
> > >  	rc = tpm_dev_add_device(chip);
> > >  	if (rc)
> > >  		goto out_err;
> > >  
> > > +	if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) {
> > > +		rc = __compat_only_sysfs_link_entry_to_kobj(&chip->pdev->kobj,
> > > +							    &chip->dev.kobj,
> > > +							    "ppi");
> > > +		if (rc)
> > > +			goto out_err;
> > > +	}
> > > +
> > >  	/* Make the chip available. */
> > >  	spin_lock(&driver_lock);
> > >  	list_add_rcu(&chip->list, &tpm_chip_list);
> > > @@ -263,6 +268,9 @@ void tpm_chip_unregister(struct tpm_chip *chip)
> > >  	spin_unlock(&driver_lock);
> > >  	synchronize_rcu();
> > >  
> > > +	if (!(chip->flags & TPM_CHIP_FLAG_TPM2))
> > > +		sysfs_remove_link(&chip->pdev->kobj, "ppi");
> > > +
> > >  	tpm1_chip_unregister(chip);
> > >  	tpm_dev_del_device(chip);
> > >  }
> > > diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> > > index 39be5ac..36ceb71 100644
> > > --- a/drivers/char/tpm/tpm.h
> > > +++ b/drivers/char/tpm/tpm.h
> > > @@ -158,8 +158,7 @@ struct tpm_vendor_specific {
> > >  
> > >  enum tpm_chip_flags {
> > >  	TPM_CHIP_FLAG_REGISTERED	= BIT(0),
> > > -	TPM_CHIP_FLAG_PPI		= BIT(1),
> > > -	TPM_CHIP_FLAG_TPM2		= BIT(2),
> > > +	TPM_CHIP_FLAG_TPM2		= BIT(1),
> > >  };
> > >  
> > >  struct tpm_chip {
> > > @@ -182,6 +181,8 @@ struct tpm_chip {
> > >  	struct dentry **bios_dir;
> > >  
> > >  #ifdef CONFIG_ACPI
> > > +	const struct attribute_group *groups[2];
> > > +	unsigned int groups_cnt;
> > >  	acpi_handle acpi_dev_handle;
> > >  	char ppi_version[TPM_PPI_VERSION_LEN + 1];
> > >  #endif /* CONFIG_ACPI */
> > > @@ -189,7 +190,7 @@ struct tpm_chip {
> > >  	struct list_head list;
> > >  };
> > >  
> > > -#define to_tpm_chip(n) container_of(n, struct tpm_chip, vendor)
> > > +#define to_tpm_chip(d) container_of(d, struct tpm_chip, dev)
> > >  
> > >  static inline void tpm_chip_put(struct tpm_chip *chip)
> > >  {
> > > @@ -419,15 +420,9 @@ void tpm_sysfs_del_device(struct tpm_chip *chip);
> > >  int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf);
> > >  
> > >  #ifdef CONFIG_ACPI
> > > -extern int tpm_add_ppi(struct tpm_chip *chip);
> > > -extern void tpm_remove_ppi(struct tpm_chip *chip);
> > > +extern void tpm_add_ppi(struct tpm_chip *chip);
> > >  #else
> > > -static inline int tpm_add_ppi(struct tpm_chip *chip)
> > > -{
> > > -	return 0;
> > > -}
> > > -
> > > -static inline void tpm_remove_ppi(struct tpm_chip *chip)
> > > +static inline void tpm_add_ppi(struct tpm_chip *chip)
> > >  {
> > >  }
> > >  #endif
> > > diff --git a/drivers/char/tpm/tpm_ppi.c b/drivers/char/tpm/tpm_ppi.c
> > > index 6ca9b5d..692a2c6 100644
> > > --- a/drivers/char/tpm/tpm_ppi.c
> > > +++ b/drivers/char/tpm/tpm_ppi.c
> > > @@ -53,7 +53,7 @@ tpm_eval_dsm(acpi_handle ppi_handle, int func, acpi_object_type type,
> > >  static ssize_t tpm_show_ppi_version(struct device *dev,
> > >  				    struct device_attribute *attr, char *buf)
> > >  {
> > > -	struct tpm_chip *chip = dev_get_drvdata(dev);
> > > +	struct tpm_chip *chip = to_tpm_chip(dev);
> > >  
> > >  	return scnprintf(buf, PAGE_SIZE, "%s\n", chip->ppi_version);
> > >  }
> > > @@ -63,7 +63,7 @@ static ssize_t tpm_show_ppi_request(struct device *dev,
> > >  {
> > >  	ssize_t size = -EINVAL;
> > >  	union acpi_object *obj;
> > > -	struct tpm_chip *chip = dev_get_drvdata(dev);
> > > +	struct tpm_chip *chip = to_tpm_chip(dev);
> > >  
> > >  	obj = tpm_eval_dsm(chip->acpi_dev_handle, TPM_PPI_FN_GETREQ,
> > >  			   ACPI_TYPE_PACKAGE, NULL);
> > > @@ -100,7 +100,7 @@ static ssize_t tpm_store_ppi_request(struct device *dev,
> > >  	int func = TPM_PPI_FN_SUBREQ;
> > >  	union acpi_object *obj, tmp;
> > >  	union acpi_object argv4 = ACPI_INIT_DSM_ARGV4(1, &tmp);
> > > -	struct tpm_chip *chip = dev_get_drvdata(dev);
> > > +	struct tpm_chip *chip = to_tpm_chip(dev);
> > >  
> > >  	/*
> > >  	 * the function to submit TPM operation request to pre-os environment
> > > @@ -156,7 +156,7 @@ static ssize_t tpm_show_ppi_transition_action(struct device *dev,
> > >  		.buffer.length = 0,
> > >  		.buffer.pointer = NULL
> > >  	};
> > > -	struct tpm_chip *chip = dev_get_drvdata(dev);
> > > +	struct tpm_chip *chip = to_tpm_chip(dev);
> > >  
> > >  	static char *info[] = {
> > >  		"None",
> > > @@ -197,7 +197,7 @@ static ssize_t tpm_show_ppi_response(struct device *dev,
> > >  	acpi_status status = -EINVAL;
> > >  	union acpi_object *obj, *ret_obj;
> > >  	u64 req, res;
> > > -	struct tpm_chip *chip = dev_get_drvdata(dev);
> > > +	struct tpm_chip *chip = to_tpm_chip(dev);
> > >  
> > >  	obj = tpm_eval_dsm(chip->acpi_dev_handle, TPM_PPI_FN_GETRSP,
> > >  			   ACPI_TYPE_PACKAGE, NULL);
> > > @@ -296,7 +296,7 @@ static ssize_t tpm_show_ppi_tcg_operations(struct device *dev,
> > >  					   struct device_attribute *attr,
> > >  					   char *buf)
> > >  {
> > > -	struct tpm_chip *chip = dev_get_drvdata(dev);
> > > +	struct tpm_chip *chip = to_tpm_chip(dev);
> > >  
> > >  	return show_ppi_operations(chip->acpi_dev_handle, buf, 0,
> > >  				   PPI_TPM_REQ_MAX);
> > > @@ -306,7 +306,7 @@ static ssize_t tpm_show_ppi_vs_operations(struct device *dev,
> > >  					  struct device_attribute *attr,
> > >  					  char *buf)
> > >  {
> > > -	struct tpm_chip *chip = dev_get_drvdata(dev);
> > > +	struct tpm_chip *chip = to_tpm_chip(dev);
> > >  
> > >  	return show_ppi_operations(chip->acpi_dev_handle, buf, PPI_VS_REQ_START,
> > >  				   PPI_VS_REQ_END);
> > > @@ -334,17 +334,16 @@ static struct attribute_group ppi_attr_grp = {
> > >  	.attrs = ppi_attrs
> > >  };
> > >  
> > > -int tpm_add_ppi(struct tpm_chip *chip)
> > > +void tpm_add_ppi(struct tpm_chip *chip)
> > >  {
> > >  	union acpi_object *obj;
> > > -	int rc;
> > >  
> > >  	if (!chip->acpi_dev_handle)
> > > -		return 0;
> > > +		return;
> > >  
> > >  	if (!acpi_check_dsm(chip->acpi_dev_handle, tpm_ppi_uuid,
> > >  			    TPM_PPI_REVISION_ID, 1 << TPM_PPI_FN_VERSION))
> > > -		return 0;
> > > +		return;
> > >  
> > >  	/* Cache PPI version string. */
> > >  	obj = acpi_evaluate_dsm_typed(chip->acpi_dev_handle, tpm_ppi_uuid,
> > > @@ -356,16 +355,5 @@ int tpm_add_ppi(struct tpm_chip *chip)
> > >  		ACPI_FREE(obj);
> > >  	}
> > >  
> > > -	rc = sysfs_create_group(&chip->pdev->kobj, &ppi_attr_grp);
> > > -
> > > -	if (!rc)
> > > -		chip->flags |= TPM_CHIP_FLAG_PPI;
> > > -
> > > -	return rc;
> > > -}
> > > -
> > > -void tpm_remove_ppi(struct tpm_chip *chip)
> > > -{
> > > -	if (chip->flags & TPM_CHIP_FLAG_PPI)
> > > -		sysfs_remove_group(&chip->pdev->kobj, &ppi_attr_grp);
> > > +	chip->groups[chip->groups_cnt++] = &ppi_attr_grp;
> > >  }
> > > -- 
> > > 2.5.0
> > > 
> > > --
> > > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> > > the body of a message to majordomo@vger.kernel.org
> > > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > > Please read the FAQ at  http://www.tux.org/lkml/
> > 
> > The commit for this patch (9b774d5cf2db4) present in the latest
> > linux-next (20151101+) breaks suspend/resume on an Acer C720 Chromebook.
> > The computer will successfully suspend but when a resume is attempted
> > a blank screen is displayed for a few seconds and then it reboots.
> 
> I think I have this same model at home (have to check). If it is, I can
> try to reproduce it today when I get back to home.

Yup, it's C720P!

> What kind of environment are you running?
> Are you able to acquire kernel logs?

Both of these questions still apply. Even if I create the same
environment, your logs might have something useful embedded.

Thank you for reporting this issue! I'll try to find a way to reproduce
and fix it at latest for -rc2.

> > -- 
> > - Jeremiah Mahler

/Jarkko