Subject: Re: [PATCH v7 4/6] tpm: of: Make of-tree specific function commonly available

From: Jarkko Sakkinen <[email-masked]>
Date: Sun, 14 Aug 2022 22:16:53 +0300

On Sun, Aug 14, 2022 at 10:16:09PM +0300, Jarkko Sakkinen wrote:
> On Fri, Aug 12, 2022 at 12:43:03PM -0400, Stefan Berger wrote:
> > Simplify tpm_read_log_of() by moving reusable parts of the code into
> > an inline function that makes it commonly available so it can be
> > used also for kexec support. Call the new of_tpm_get_sml_parameters()
> > function from the TPM Open Firmware driver.
> > 
> > Signed-off-by: Stefan Berger <[email-masked]>
> > Cc: Jarkko Sakkinen <[email-masked]>
> > Cc: Jason Gunthorpe <[email-masked]>
> > Cc: Rob Herring <[email-masked]>
> > Cc: Frank Rowand <[email-masked]>
> > Reviewed-by: Mimi Zohar <[email-masked]>
> > Tested-by: Nageswara R Sastry <[email-masked]>
> > 
> > ---
> > v7:
> >  - Added original comment back into inlined function
> > 
> > v4:
> >  - converted to inline function
> > ---
> >  drivers/char/tpm/eventlog/of.c | 31 +++++------------------------
> >  include/linux/tpm.h            | 36 ++++++++++++++++++++++++++++++++++
> >  2 files changed, 41 insertions(+), 26 deletions(-)
> > 
> > diff --git a/drivers/char/tpm/eventlog/of.c b/drivers/char/tpm/eventlog/of.c
> > index a9ce66d09a75..f9462d19632e 100644
> > --- a/drivers/char/tpm/eventlog/of.c
> > +++ b/drivers/char/tpm/eventlog/of.c
> > @@ -12,6 +12,7 @@
> >  
> >  #include <linux/slab.h>
> >  #include <linux/of.h>
> > +#include <linux/tpm.h>
> >  #include <linux/tpm_eventlog.h>
> >  
> >  #include "../tpm.h"
> > @@ -20,11 +21,10 @@
> >  int tpm_read_log_of(struct tpm_chip *chip)
> >  {
> >  	struct device_node *np;
> > -	const u32 *sizep;
> > -	const u64 *basep;
> >  	struct tpm_bios_log *log;
> >  	u32 size;
> >  	u64 base;
> > +	int ret;
> >  
> >  	log = &chip->log;
> >  	if (chip->dev.parent && chip->dev.parent->of_node)
> > @@ -35,30 +35,9 @@ int tpm_read_log_of(struct tpm_chip *chip)
> >  	if (of_property_read_bool(np, "powered-while-suspended"))
> >  		chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
> >  
> > -	sizep = of_get_property(np, "linux,sml-size", NULL);
> > -	basep = of_get_property(np, "linux,sml-base", NULL);
> > -	if (sizep == NULL && basep == NULL)
> > -		return -ENODEV;
> > -	if (sizep == NULL || basep == NULL)
> > -		return -EIO;
> > -
> > -	/*
> > -	 * For both vtpm/tpm, firmware has log addr and log size in big
> > -	 * endian format. But in case of vtpm, there is a method called
> > -	 * sml-handover which is run during kernel init even before
> > -	 * device tree is setup. This sml-handover function takes care
> > -	 * of endianness and writes to sml-base and sml-size in little
> > -	 * endian format. For this reason, vtpm doesn't need conversion
> > -	 * but physical tpm needs the conversion.
> > -	 */
> > -	if (of_property_match_string(np, "compatible", "IBM,vtpm") < 0 &&
> > -	    of_property_match_string(np, "compatible", "IBM,vtpm20") < 0) {
> > -		size = be32_to_cpup((__force __be32 *)sizep);
> > -		base = be64_to_cpup((__force __be64 *)basep);
> > -	} else {
> > -		size = *sizep;
> > -		base = *basep;
> > -	}
> > +	ret = of_tpm_get_sml_parameters(np, &base, &size);
> > +	if (ret < 0)
> > +		return ret;
> >  
> >  	if (size == 0) {
> >  		dev_warn(&chip->dev, "%s: Event log area empty\n", __func__);
> > diff --git a/include/linux/tpm.h b/include/linux/tpm.h
> > index dfeb25a0362d..6356baaa1393 100644
> > --- a/include/linux/tpm.h
> > +++ b/include/linux/tpm.h
> > @@ -460,4 +460,40 @@ static inline struct tpm_chip *tpm_default_chip(void)
> >  	return NULL;
> >  }
> >  #endif
> > +
> > +#ifdef CONFIG_OF
> > +static inline int of_tpm_get_sml_parameters(struct device_node *np,
> > +					    u64 *base, u32 *size)
> > +{
> > +	const u32 *sizep;
> > +	const u64 *basep;
> > +
> > +	sizep = of_get_property(np, "linux,sml-size", NULL);
> > +	basep = of_get_property(np, "linux,sml-base", NULL);
> > +	if (sizep == NULL && basep == NULL)
> > +		return -ENODEV;
> > +	if (sizep == NULL || basep == NULL)
> > +		return -EIO;
> > +
> > +	/*
> > +	 * For both vtpm/tpm, firmware has log addr and log size in big
> > +	 * endian format. But in case of vtpm, there is a method called
> > +	 * sml-handover which is run during kernel init even before
> > +	 * device tree is setup. This sml-handover function takes care
> > +	 * of endianness and writes to sml-base and sml-size in little
> > +	 * endian format. For this reason, vtpm doesn't need conversion
> > +	 * but physical tpm needs the conversion.
> > +	 */
> > +	if (of_property_match_string(np, "compatible", "IBM,vtpm") < 0 &&
> > +	    of_property_match_string(np, "compatible", "IBM,vtpm20") < 0) {
> > +		*size = be32_to_cpup((__force __be32 *)sizep);
> > +		*base = be64_to_cpup((__force __be64 *)basep);
> > +	} else {
> > +		*size = *sizep;
> > +		*base = *basep;
> > +	}
> > +	return 0;
> > +}
> > +#endif
> > +
> >  #endif
> > -- 
> > 2.35.1
> > 
> 
> Reviewed-by: Jarkko Sakkinen <[email-masked]>
> 
> BR, Jarkkko

Should I pick this or will the full patch set be picked
by someone?

BR, Jarkko