gpu-compute: Support Scalar and Vector access to system pages
The amdgpu driver supports reading and writing scalar and vector memory
addresses that reside in system memory. This is commonly used for things
like blit kernels that perform host-to-device or device-to-host copies
using GPU load/store instructions.
This is done by utilizing the system hub device added in a prior
changeset. Memory packets translated by the Scalar or VMEM TLBs will
have the correspoding system request field set from the PTE in the TLB
which can be used in the compute unit to determine if a request is for
system memory or not.
Another important change is to return global memory tokens for system
requests. Since these do not flow through the GPU coalescer where the
token is returned, the token can be returned once the request is known
to be a system request.
Change-Id: I35030e0b3698f10c63a397f96b81267271e3130e
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/57711
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Maintainer: Matt Sinclair <mattdsinclair@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
4 files changed
