class BandwidthBuddyPageMask
Defined at line 466 of file ../../src/graphics/display/drivers/intel-display/registers-arbiter.h
BW_BUDDY_PAGE_MASK (Bandwidth Buddy Page Mask)
This register has bits that are reserved but not MBZ (must be zero). So, it
can only be safely updated via read-modify-write operations.
This register is not documented on Kaby Lake or Skylake.
Rocket Lake: IHD-OS-RKL-Vol 2-7.22 page 32
Tiger Lake: IHD-OS-TGL-Vol 2c-1.22-Rev2.0 Part 1 page 173
DG1: IHD-OS-DG1-Vol 2c-2.21 Part 2 page 138
Public Members
field_RsvdZ_468 field_address_page_mask_483Public Methods
template <, >typename SelfType::ValueType address_page_mask ()The address bits masked for buddy address comparison.
The buddy system determines if two memory requests can be paired by
comparing bits 36-9 of the requests' physical addresses. However, the
comparison ignores the bits whose corresponding mask bits in this field are
set to 1. Conceptually, bits 36-9 in the physical address are ANDed with
the inverse (NOT) of bits 27-0 in this field before going into the
comparator.
This field accounts for the system's DRAM configuration. The intent is that
the buddy system improves DRAM bandwidth efficiency by pairing up memory
requests in a way that cuts down on DRAM management operations, such as
opening rows.
Defined at line 483 of file ../../src/graphics/display/drivers/intel-display/registers-arbiter.h
template <, >SelfType & set_address_page_mask (typename SelfType::ValueType val)The address bits masked for buddy address comparison.
The buddy system determines if two memory requests can be paired by
comparing bits 36-9 of the requests' physical addresses. However, the
comparison ignores the bits whose corresponding mask bits in this field are
set to 1. Conceptually, bits 36-9 in the physical address are ANDed with
the inverse (NOT) of bits 27-0 in this field before going into the
comparator.
This field accounts for the system's DRAM configuration. The intent is that
the buddy system improves DRAM bandwidth efficiency by pairing up memory
requests in a way that cuts down on DRAM management operations, such as
opening rows.
Defined at line 483 of file ../../src/graphics/display/drivers/intel-display/registers-arbiter.h
hwreg::RegisterAddr<BandwidthBuddyPageMask> GetForArbiter (int arbiter_index)Tiger Lake has two bandwidth buddy instances, at indexes 1 and 2.
Rocket Lake, has a single bandwidth buddy instance, at index 0.
Defined at line 487 of file ../../src/graphics/display/drivers/intel-display/registers-arbiter.h