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

Jarkko Sakkinen
2022-08-14T19:17:01Z

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 <stefanb@linux.ibm.com>
> > Cc: Jarkko Sakkinen <jarkko@kernel.org>
> > Cc: Jason Gunthorpe <jgg@ziepe.ca>
> > Cc: Rob Herring <robh+dt@kernel.org>
> > Cc: Frank Rowand <frowand.list@gmail.com>
> > Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
> > Tested-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
> >
> > ---
> > 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 <jarkko@kernel.org>
>
> BR, Jarkkko

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

BR, Jarkko