drm/gpusvm: make the DMA mapping step in get_pages() optional

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Some drivers (e.g. AMDXDNA) only need the CPU pages faulted in and tracked
by the notifier, no need DMA mapping.

Add a drm_gpusvm_ctx::no_dma_map flag. When set, get_pages() does the
shared HMM fault and records notifier_seq, but skips svm_pages->drm
validation, the dma_addr allocation and drm_gpusvm_dma_map_pages().
With no mapping state to check, the fault is redone on every call. The
default (no_dma_map == 0) is unchanged.

Suggested-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Honglei Huang <honghuan@amd.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patch.msgid.link/20260905133142.3628027-5-honghuan@amd.com

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This commit is contained in:

Honglei Huang 2026-09-05 21:31:40 +08:00 • committed by Matthew Brost

parent cc2a6cbd68

commit 22a81666c2

2 changed files with 41 additions and 12 deletions

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44

drivers/gpu/drm/drm_gpusvm.c

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9

include/drm/drm_gpusvm.h

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