On 12/12/2016 08:10 PM, Jarkko Sakkinen wrote:
> On Sun, Dec 11, 2016 at 12:35:32AM -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.
>
> Will other device tree using firmwares than OF use the same bindings?
Yes, that is what expected that all other device tree using firmware
will also use same bindings.
Thanks & Regards,
- Nayna
>
>> 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..de57d4a 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 size;
>> + u64 base;
>>
>> 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) {
>> + size = be32_to_cpup(sizep);
>> + base = be64_to_cpup(basep);
>> + } else {
>> + size = *sizep;
>> + base = *basep;
>> + }
>> +
>> + if (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(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 + size;
>>
>> - memcpy(log->bios_event_log, __va(*basep), *sizep);
>> + memcpy(log->bios_event_log, __va(base), size);
>>
>> return 0;
>> }
>> --
>> 2.5.0
>>
>
> Reviewed-by: Jarkko Sakkinen <[email protected]>
>
> /Jarkko
>
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