Справочник Пользователя для HP A2Y15AV

Datasheet, Volume 2

291

Processor Configuration Registers 

This register invalidates IOTLB. The act of writing the upper byte of the IOTLB_REG 
with IVT field set causes the hardware to perform the IOTLB invalidation.

63

RW-V

0h

Uncore

Invalidate IOTLB (IVT) 
Software requests IOTLB invalidation by setting this field. 

Software must also set the requested invalidation granularity by 

programming the IIRG field.
Hardware clears the IVT field to indicate the invalidation request 

is complete. Hardware also indicates the granularity at which the 

invalidation operation was performed through the IAIG field. 

Software must not submit another invalidation request through 

this register while the IVT field is set, nor update the associated 

Invalidate Address register.
Software must not submit IOTLB invalidation requests when 

there is a context-cache invalidation request pending at this 

remapping hardware unit.
Hardware implementations reporting write-buffer flushing 

requirement (RWBF=1 in Capability register) must implicitly 

perform a write buffer flushing before invalidating the IOTLB.

62:62

RO

0h

61:60

RW

0h

Uncore

IOTLB Invalidation Request Granularity (IIRG) 
When requesting hardware to invalidate the IOTLB (by setting 

the IVT field), software writes the requested invalidation 

granularity through this field. The following are the encodings for 

the field.
00 =  Reserved.
01 =  Global invalidation request.
10 =  Domain-selective invalidation request. The target domain-

id must be specified in the DID field.

11 =  Page-selective invalidation request. The target address, 

mask and invalidation hint must be specified in the 

Invalidate Address register, and the domain-id must be 

provided in the DID field.

Hardware implementations may process an invalidation request 

by performing invalidation at a coarser granularity than 

requested. Hardware indicates completion of the invalidation 

request by clearing the IVT field. At this time, the granularity at 

which actual invalidation was performed is reported through the 

IAIG field

59:59

RO

0h