Re: [PATCH v3 2/2] tpm: Add reserved memory event log

Jarkko Sakkinen
2023-01-26T22:01:01Z

On Thu, Jan 26, 2023 at 09:42:55PM +0000, Jarkko Sakkinen wrote:
> On Thu, Jan 26, 2023 at 03:08:10PM -0600, Eddie James wrote:
> > Some platforms may desire to pass the event log up to Linux in the
> > form of a reserved memory region. In particular, this is desirable
> > for embedded systems or baseboard management controllers (BMCs)
> > booting with U-Boot. IBM OpenBMC BMCs will be the first user.
> > Add support for the reserved memory in the TPM core to find the
> > region and map it.
> >
> > Signed-off-by: Eddie James <eajames@linux.ibm.com>
> > ---
> > drivers/char/tpm/eventlog/of.c | 38 +++++++++++++++++++++++++++++++++-
> > 1 file changed, 37 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/char/tpm/eventlog/of.c b/drivers/char/tpm/eventlog/of.c
> > index 741ab2204b11..c815cadf00a4 100644
> > --- a/drivers/char/tpm/eventlog/of.c
> > +++ b/drivers/char/tpm/eventlog/of.c
> > @@ -12,12 +12,48 @@
> >
> > #include <linux/device.h>
> > #include <linux/slab.h>
> > +#include <linux/io.h>
> > +#include <linux/ioport.h>
> > #include <linux/of.h>
> > +#include <linux/of_address.h>
> > +#include <linux/of_reserved_mem.h>
> > #include <linux/tpm_eventlog.h>
> >
> > #include "../tpm.h"
> > #include "common.h"
> >
> > +static int tpm_read_log_memory_region(struct tpm_chip *chip)
> > +{
> > + struct device_node *node;
> > + struct resource res;
> > + int rc;
> > +
> > + node = of_parse_phandle(chip->dev.parent->of_node, "memory-region", 0);
> > + if (!node) {
> > + dev_info(&chip->dev, "no phandle\n");
> > + return -ENODEV;
> > + }
> > +
> > + rc = of_address_to_resource(node, 0, &res);
> > + of_node_put(node);
> > + if (rc) {
> > + dev_info(&chip->dev, "no mem\n");
> > + return rc;
> > + }
> > +
> > + chip->log.bios_event_log = devm_memremap(&chip->dev, res.start, resource_size(&res),
> > + MEMREMAP_WB);
> > + if (!chip->log.bios_event_log) {
> > + dev_info(&chip->dev, "err memremap\n");
> > + return -ENOMEM;
> > + }
> > +
> > + chip->log.bios_event_log_end = chip->log.bios_event_log + resource_size(&res);
> > +
> > + return chip->flags & TPM_CHIP_FLAG_TPM2 ? EFI_TCG2_EVENT_LOG_FORMAT_TCG_2 :
> > + EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
> > +}
> > +
> > int tpm_read_log_of(struct tpm_chip *chip)
> > {
> > struct device_node *np;
> > @@ -39,7 +75,7 @@ int tpm_read_log_of(struct tpm_chip *chip)
> > 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;
> > + return tpm_read_log_memory_region(chip);
> > if (sizep == NULL || basep == NULL)
> > return -EIO;
> >
> > --
> > 2.31.1
> >
>
> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>

I applied the patches.

BR, Jarkko