drm/amdkfd: correct vram_available calculation

reserve_mem_limit() computes available VRAM as
	vram_size - reserved - vram_pin_size - kfd.vram_used
However, kfd.vram_used already includes BOs that are later pinned.
Pinning does not consume extra VRAM. Subtracting
vram_pin_size counts those bytes twice and causes fake-OOM
while VRAM is still free.

Reuse get_available_memory() in reserve_mem_limit(). Move
ALIGN_DOWN to the ioctl so the userspace ABI is unchanged. The
VRAM counter is a parameter: the ioctl passes vram_used_aligned[],
the gate passes vram_used[] so a 4K BO is not charged 2MB.

kfd.vram_pinned is only updated in gpuvm_pin_bo(). dma-buf pin
calls amdgpu_bo_pin() only, so the counter stays zero. Update it
from amdgpu_bo_pin() through a KFD helper, on first pin and last
unpin, matching vram_pin_size.

Track per-XCP pins in vram_pin_size_xcp[] and kfd.vram_pinned[].
Pins that are not owned by a single partition go to
vram_pin_size_common, which every partition subtracts.

A KFD VRAM BO always carries a partition, so the KFD credit is only
correct for xcp >= 0. Call the helper for both branches and let it
warn once and skip if that ever stops holding: without the credit the
BO would be subtracted through vram_pin_size_common and never added
back, which is the double counting this patch removes, and
kfd.vram_pinned[] would be indexed out of bounds.

Suggested-by: Philip Yang <Philip.Yang@amd.com>
Signed-off-by: Zhen Han <Zhen.Han@amd.com>
Reviewed-by: Mukul Joshi <mukul.joshi@amd.com>
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 894cbb31c50e3cf49657130396bbf6c0475304e4)
Cc: stable@vger.kernel.org

0 files changed, 0 insertions, 0 deletions