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

[Jarkko Sakkinen <jarkko@kernel.org>]

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