iommu/amd: Enable PerfOpt automatically for integrated GPUs

PerfOpt is usable by integrated GPUs in identity mode. Enable it from
the IOMMU driver's domain attachment paths instead of requiring an
amdgpu policy knob and exported enable/disable interfaces.

Mark supported integrated GPUs as PerfOpt-eligible when selecting their
default identity domain. Skip GCR3 setup and ATS/PRI/PASID enablement for
these identity attachments, then enable PerfOpt after installing the DTE.
Clear PerfOpt before attaching an eligible GPU to a translated or blocked
domain, including unmanaged domains used by VFIO. Propagate failures to
clear bypass, but keep a completed identity attachment successful if the
optional PerfOpt enable fails.

Clear inherited PerfOpt state during initialization, including when a crash
kernel reuses device tables. Read feature support directly from hardware
because cached features may not be available yet, and stop initialization
if the initial clear fails.

Each IOMMU has at most one PerfOpt-eligible GPU, so track activation with a
boolean under the IOMMU lock. Preserve this state while clearing hardware
at suspend and shutdown, and restore the bit on resume only where it was
active. Do not enable PerfOpt unconditionally during early IOMMU
initialization.

Remove the amdgpu parameter, driver callbacks, and exported interfaces.
Translated attachments retain their normal device capability setup.

Suggested-by: Jason Gunthorpe <jgg@ziepe.ca>
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

0 files changed, 0 insertions, 0 deletions