2023-04-13 01:32:02

by David E. Box

Subject: [PATCH] platform/x86/intel/pmt: Ignore uninitialized entries

On Intel Xeon, unused PMT regions will have uninitialized discovery headers
containing all 0xF. Instead of returning an error, just skip the region.

Signed-off-by: David E. Box <[email protected]>
---
drivers/platform/x86/intel/pmt/telemetry.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/platform/x86/intel/pmt/telemetry.c b/drivers/platform/x86/intel/pmt/telemetry.c
index 71cdef42084a..39cbc87cc28a 100644
--- a/drivers/platform/x86/intel/pmt/telemetry.c
+++ b/drivers/platform/x86/intel/pmt/telemetry.c
@@ -78,7 +78,7 @@ static int pmt_telem_header_decode(struct intel_pmt_entry *entry,
* reserved for future use. They have zero size. Do not fail
* probe for these. Just ignore them.
*/
- if (header->size == 0)
+ if (header->size == 0 || header->access_type == 0xF)
return 1;

return 0;

base-commit: 5b309e80f457ebb41770e0122766825a78cfc11b
prerequisite-patch-id: a3bf21940fa02eb2f3adb4bd2d3a93df14df077a
--
2.34.1

2023-04-13 10:15:18

by Ilpo Järvinen

Subject: Re: [PATCH] platform/x86/intel/pmt: Ignore uninitialized entries

On Wed, 12 Apr 2023, David E. Box wrote:

> On Intel Xeon, unused PMT regions will have uninitialized discovery headers
> containing all 0xF. Instead of returning an error, just skip the region.
>
> Signed-off-by: David E. Box <[email protected]>
> ---
> drivers/platform/x86/intel/pmt/telemetry.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/platform/x86/intel/pmt/telemetry.c b/drivers/platform/x86/intel/pmt/telemetry.c
> index 71cdef42084a..39cbc87cc28a 100644
> --- a/drivers/platform/x86/intel/pmt/telemetry.c
> +++ b/drivers/platform/x86/intel/pmt/telemetry.c
> @@ -78,7 +78,7 @@ static int pmt_telem_header_decode(struct intel_pmt_entry *entry,
> * reserved for future use. They have zero size. Do not fail
> * probe for these. Just ignore them.
> */
> - if (header->size == 0)
> + if (header->size == 0 || header->access_type == 0xF)
> return 1;
>
> return 0;

Reviewed-by: Ilpo J?rvinen <[email protected]>


--
i.

2023-04-17 10:33:50

by Hans de Goede

Subject: Re: [PATCH] platform/x86/intel/pmt: Ignore uninitialized entries

Hi,

On 4/13/23 12:13, Ilpo Järvinen wrote:
> On Wed, 12 Apr 2023, David E. Box wrote:
>
>> On Intel Xeon, unused PMT regions will have uninitialized discovery headers
>> containing all 0xF. Instead of returning an error, just skip the region.
>>
>> Signed-off-by: David E. Box <[email protected]>
>> ---
>> drivers/platform/x86/intel/pmt/telemetry.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/platform/x86/intel/pmt/telemetry.c b/drivers/platform/x86/intel/pmt/telemetry.c
>> index 71cdef42084a..39cbc87cc28a 100644
>> --- a/drivers/platform/x86/intel/pmt/telemetry.c
>> +++ b/drivers/platform/x86/intel/pmt/telemetry.c
>> @@ -78,7 +78,7 @@ static int pmt_telem_header_decode(struct intel_pmt_entry *entry,
>> * reserved for future use. They have zero size. Do not fail
>> * probe for these. Just ignore them.
>> */
>> - if (header->size == 0)
>> + if (header->size == 0 || header->access_type == 0xF)
>> return 1;
>>
>> return 0;
>
> Reviewed-by: Ilpo Järvinen <[email protected]>

Thank you both for the patch + review, I've applied this patch
to my review-hans branch:
https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans

Note it will show up in my review-hans branch once I've pushed my
local branch there, which might take a while.

Once I've run some tests on this branch the patches there will be
added to the platform-drivers-x86/for-next branch and eventually
will be included in the pdx86 pull-request to Linus for the next
merge-window.

Regards,

Hans