drm/gpusvm: Limit the number of retries in drm_gpusvm_get_pages

drm_gpusvm_get_pages should not be allowed to retry forever, cap the
time spent in the function to HMM_RANGE_DEFAULT_TIMEOUT has this is
essentially a wrapper around hmm_range_fault.

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Link: https://patch.msgid.link/20251122012502.382587-1-matthew.brost@intel.com

diff --git a/drivers/gpu/drm/drm_gpusvm.c b/drivers/gpu/drm/drm_gpusvm.c
index 73e550c8ff8c986ba4ccb47427ae2cc0fcae9b97..39c8c50401dd068d5be43c049997168630744201 100644 (file)
--- a/drivers/gpu/drm/drm_gpusvm.c
+++ b/drivers/gpu/drm/drm_gpusvm.c
@@ -1288,6 +1288,9 @@ int drm_gpusvm_get_pages(struct drm_gpusvm *gpusvm,
                                                           DMA_BIDIRECTIONAL;
 
 retry:
+       if (time_after(jiffies, timeout))
+               return -EBUSY;
+
        hmm_range.notifier_seq = mmu_interval_read_begin(notifier);
        if (drm_gpusvm_pages_valid_unlocked(gpusvm, svm_pages))
                goto set_seqno;