drm/xe/pf: Limit fair VF LMEM provisioning

[ Upstream commit bf07ca963d4fd11c88a9d4b058f2bd62e8d46a98 ]

Due to the current design of the BO and VRAM manager, any object
with XE_BO_FLAG_PINNED flag, which the PF driver uses during VF
LMEM provisionining, is created with the TTM_PL_FLAG_CONTIGUOUS
flag, which may cause VRAM fragmentation that prevents subsequent
allocations of larger objects, like fair VF LMEM provisioning.

To avoid such failures, round down fair VF LMEM provisioning size
to next power of two size, to compensate what xe_ttm_vram_mgr is
doing to achieve contiguous allocations.

Fixes: ac6598aed1b3 ("drm/xe/pf: Add support to configure SR-IOV VFs")
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Piotr Piórkowski <piotr.piorkowski@intel.com>
Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240711192320.1198-2-michal.wajdeczko@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
(cherry picked from commit 4c3fe5eae46b92e2fd961b19f7779608352e5368)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Michal Wajdeczko 2024-07-11 21:23:19 +02:00 committed by Greg Kroah-Hartman
parent fa1c57d107
commit 70500f4fce

View File

@ -1527,6 +1527,7 @@ static u64 pf_estimate_fair_lmem(struct xe_gt *gt, unsigned int num_vfs)
u64 fair;
fair = div_u64(available, num_vfs);
fair = rounddown_pow_of_two(fair); /* XXX: ttm_vram_mgr & drm_buddy limitation */
fair = ALIGN_DOWN(fair, alignment);
#ifdef MAX_FAIR_LMEM
fair = min_t(u64, MAX_FAIR_LMEM, fair);