diff mbox

[v6,1/2] tpm: enhance read_log_of() to support Physical TPM event log

Message ID 1480164339-26409-2-git-send-email-nayna@linux.vnet.ibm.com
State New
Headers show

Commit Message

Nayna Nov. 26, 2016, 12:45 p.m. UTC
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 <nayna@linux.vnet.ibm.com>
---
 drivers/char/tpm/tpm_of.c | 27 +++++++++++++++++++++++----
 1 file changed, 23 insertions(+), 4 deletions(-)

Comments

Jarkko Sakkinen Nov. 26, 2016, 4:15 p.m. UTC | #1
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 <nayna@linux.vnet.ibm.com>
> ---
>  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?

>  
>  	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?

>  
>  	return 0;
>  }
> -- 
> 2.5.0
> 

/Jarkko
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Nayna Nov. 29, 2016, 9:37 a.m. UTC | #2
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 <nayna@linux.vnet.ibm.com>
>> ---
>>   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
>

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diff mbox

Patch

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;
 
 	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);
 
 	return 0;
 }