On 11/26/2016 09:45 PM, Jarkko Sakkinen wrote:
> On Sat, Nov 26, 2016 at 07:45:38AM -0500, Nayna Jain wrote:
>> Physical TPMs use Open Firmware Device Tree bindings that are similar
>> to the IBM Power virtual TPM to support event log. However, these
>> properties store the values in different endianness for Physical
>> and Virtual TPM.
>>
>> This patch fixes the endianness issue by doing appropriate conversion
>> based on Physical or Virtual TPM.
>>
>> Signed-off-by: Nayna Jain <[email protected]>
>> ---
>>   drivers/char/tpm/tpm_of.c | 27 +++++++++++++++++++++++----
>>   1 file changed, 23 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/char/tpm/tpm_of.c b/drivers/char/tpm/tpm_of.c
>> index 7dee42d7..4b0d5e6 100644
>> --- a/drivers/char/tpm/tpm_of.c
>> +++ b/drivers/char/tpm/tpm_of.c
>> @@ -27,6 +27,8 @@ int tpm_read_log_of(struct tpm_chip *chip)
>>      const u32 *sizep;
>>      const u64 *basep;
>>      struct tpm_bios_log *log;
>> +    u32 log_size;
>> +    u64 log_base;
>
> Maybe just base and size?

Hmm.. okay to keep names short, I can change to base/size. And since 
they are used within log function, probably it is implicit that, these 
refer to Log  base address and size.

>
>>
>>      log = &chip->log;
>>      if (chip->dev.parent && chip->dev.parent->of_node)
>> @@ -41,18 +43,35 @@ int tpm_read_log_of(struct tpm_chip *chip)
>>      if (sizep == NULL || basep == NULL)
>>              return -EIO;
>>
>> -    if (*sizep == 0) {
>> +    /*
>> +     * 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) {
>> +            log_size = be32_to_cpup(sizep);
>> +            log_base = be64_to_cpup(basep);
>> +    } else {
>> +            log_size = *sizep;
>> +            log_base = *basep;
>> +    }
>> +
>> +    if (log_size == 0) {
>>              dev_warn(&chip->dev, "%s: Event log area empty\n", __func__);
>>              return -EIO;
>>      }
>>
>> -    log->bios_event_log = kmalloc(*sizep, GFP_KERNEL);
>> +    log->bios_event_log = kmalloc(log_size, GFP_KERNEL);
>>      if (!log->bios_event_log)
>>              return -ENOMEM;
>>
>> -    log->bios_event_log_end = log->bios_event_log + *sizep;
>> +    log->bios_event_log_end = log->bios_event_log + log_size;
>>
>> -    memcpy(log->bios_event_log, __va(*basep), *sizep);
>> +    memcpy(chip->log.bios_event_log, __va(log_base), log_size);
>
> Why did you change the first parameter?

Hmm.. yeah..shouldn't be.  Sorry, I think while redoing, I mixed up with 
my previous versions. Will change it.
Thanks for noticing it.

Thanks & Regards,
    - Nayna

>
>>
>>      return 0;
>>   }
>> --
>> 2.5.0
>>
>
> /Jarkko
>


------------------------------------------------------------------------------
_______________________________________________
tpmdd-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/tpmdd-devel

Reply via email to