AMDGPU Glossary

Here you can find some generic acronyms used in the amdgpu driver. Notice that we have a dedicated glossary for Display Core at ‘DC Glossary’.

active_cu_number

The number of CUs that are active on the system. The number of active CUs may be less than SE * SH * CU depending on the board configuration.

BACO

Bus Alive, Chip Off

BOCO

Bus Off, Chip Off

CE

Constant Engine

CIK

Sea Islands

CB

Color Buffer

CP

Command Processor

CPC

Command Processor Compute

CPF

Command Processor Fetch

CPG

Command Processor Graphics

CPLIB

Content Protection Library

CS

Command Submission

CSB

Clear State Indirect Buffer

CU

Compute Unit

DB

Depth Buffer

DFS

Digital Frequency Synthesizer

ECP

Enhanced Content Protection

EOP

End Of Pipe/Pipeline

FLR

Function Level Reset

GART

Graphics Address Remapping Table. This is the name we use for the GPUVM page table used by the GPU kernel driver. It remaps system resources (memory or MMIO space) into the GPU’s address space so the GPU can access them. The name GART harkens back to the days of AGP when the platform provided an MMU that the GPU could use to get a contiguous view of scattered pages for DMA. The MMU has since moved on to the GPU, but the name stuck.

GC

Graphics and Compute

GDS

Global Data Share

GE

Geometry Engine

GMC

Graphic Memory Controller

GPR

General Purpose Register

GPUVM

GPU Virtual Memory. This is the GPU’s MMU. The GPU supports multiple virtual address spaces that can be in flight at any given time. These allow the GPU to remap VRAM and system resources into GPU virtual address spaces for use by the GPU kernel driver and applications using the GPU. These provide memory protection for different applications using the GPU.

GTT

Graphics Translation Tables. This is a memory pool managed through TTM which provides access to system resources (memory or MMIO space) for use by the GPU. These addresses can be mapped into the “GART” GPUVM page table for use by the kernel driver or into per process GPUVM page tables for application usage.

GWS

Global Wave Sync

IH

Interrupt Handler

IV

Interrupt Vector

HQD

Hardware Queue Descriptor

IB

Indirect Buffer

IMU

Integrated Management Unit (Power Management support)

IP

Intellectual Property blocks

KCQ

Kernel Compute Queue

KFD

Kernel Fusion Driver

KGQ

Kernel Graphics Queue

KIQ

Kernel Interface Queue

MC

Memory Controller

MCBP

Mid Command Buffer Preemption

ME

MicroEngine (Graphics)

MEC

MicroEngine Compute

MES

MicroEngine Scheduler

MMHUB

Multi-Media HUB

MQD

Memory Queue Descriptor

PA

Primitive Assembler / Physical Address

PDE

Page Directory Entry

PFP

Pre-Fetch Parser (Graphics)

PPLib

PowerPlay Library - PowerPlay is the power management component.

PRT

Partially Resident Texture (also known as sparse residency)

PSP

Platform Security Processor

PTE

Page Table Entry

RB

Render Backends. Some people called it ROPs.

RLC

RunList Controller. This name is a remnant of past ages and doesn’t have much meaning today. It’s a group of general-purpose helper engines for the GFX block. It’s involved in GFX power management and SR-IOV, among other things.

SC

Scan Converter

SDMA

System DMA

SE

Shader Engine

SGPR

Scalar General-Purpose Registers

SH

SHader array

SI

Southern Islands

SMU/SMC

System Management Unit / System Management Controller

SPI (AMDGPU)

Shader Processor Input

SRLC

Save/Restore List Control

SRLG

Save/Restore List GPM_MEM

SRLS

Save/Restore List SRM_MEM

SS

Spread Spectrum

SX

Shader Export

TA

Trusted Application

TC

Texture Cache

TCP (AMDGPU)

Texture Cache per Pipe. Even though the name “Texture” is part of this acronym, the TCP represents the path to memory shaders; i.e., it is not related to texture. The name is a leftover from older designs where shader stages had different cache designs; it refers to the L1 cache in older architectures.

TMR

Trusted Memory Region

TMZ

Trusted Memory Zone

TOC

Table of Contents

UMC

Unified Memory Controller

UMSCH

User Mode Scheduler

UTC (AMDGPU)

Unified Translation Cache. UTC is equivalent to TLB. You might see a variation of this acronym with L at the end, i.e., UTCL followed by a number; L means the cache level (e.g., UTCL1 and UTCL2).

UVD

Unified Video Decoder

VCE

Video Compression Engine

VCN

Video Codec Next

VGPR

Vector General-Purpose Registers

VMID

Virtual Memory ID

VPE

Video Processing Engine

XCC

Accelerator Core Complex

XCP

Accelerator Core Partition