On 9/15/2023 9:46 AM, Ilpo Järvinen wrote:
> On Wed, 13 Sep 2023, Jithu Joseph wrote:
>
>> Scan image loading flow for newer IFS generations (1 and 2) are slightly
>> different from that of current generation (0). In newer schemes,
>> loading need not be done once for each socket as was done in gen0.
>>
>> Also the width of CHUNK related bitfields in SCAN_HASHES_STATUS MSR has
>> increased from 8 -> 16 bits. Similarly there are width differences
>> for CHUNK_AUTHENTICATION_STATUS too.
>>
>> Further the parameter to AUTHENTICATE_AND_COPY_CHUNK is passed
>> differently in newer generations.
>>
>> Signed-off-by: Jithu Joseph <jithu.joseph@xxxxxxxxx>
>> Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
>> Tested-by: Pengfei Xu <pengfei.xu@xxxxxxxxx>
>> ---
>> drivers/platform/x86/intel/ifs/ifs.h | 27 ++++++
>> drivers/platform/x86/intel/ifs/load.c | 113 +++++++++++++++++++++++++-
>> 2 files changed, 138 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/platform/x86/intel/ifs/ifs.h b/drivers/platform/x86/intel/ifs/ifs.h
>> index d666aeed20fc..886dc74de57d 100644
>> --- a/drivers/platform/x86/intel/ifs/ifs.h
>> +++ b/drivers/platform/x86/intel/ifs/ifs.h
>> @@ -137,6 +137,8 @@
>> #define MSR_CHUNKS_AUTHENTICATION_STATUS 0x000002c5
>> #define MSR_ACTIVATE_SCAN 0x000002c6
>> #define MSR_SCAN_STATUS 0x000002c7
>> +#define MSR_SAF_CTRL 0x000004f0
>> +
>> #define SCAN_NOT_TESTED 0
>> #define SCAN_TEST_PASS 1
>> #define SCAN_TEST_FAIL 2
>> @@ -158,6 +160,19 @@ union ifs_scan_hashes_status {
>> };
>> };
>>
>> +union ifs_scan_hashes_status_gen2 {
>> + u64 data;
>> + struct {
>> + u16 chunk_size;
>> + u16 num_chunks;
>> + u8 error_code;
>> + u32 chunks_in_stride :9;
>> + u32 rsvd :2;
>> + u32 max_core_limit :12;
>> + u32 valid :1;
>
> This doesn't look it would be guaranteed to provide the alignment you seem
> to want for the fields.
To Quote Tony from an earlier response to a similar query[1]
"This driver is X86_64 specific (and it seems
incredibly unlikely that some other architecture will copy this h/w
interface so closely that they want to re-use this driver. There's an x86_64
ABI that says how bitfields in C are allocated."
[1] https://lore.kernel.org/lkml/SJ1PR11MB6083EBD2D2826E0A247AF242FCD19@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
Agree to the rest of your comments ... will revise them as per your suggestion.
Jithu
