sema: add walk_probe - trace the page-table walk for a VA

New module parameter walk_probe <va> runs the recorded-va-space walks and
the discovered-directory walk directly (pin/lat/pair map bypassed) with
per-level tracing, and prints the result of each. This separates 'the
page tables are not walkable' from 'the VA->PA pair map already answers'
when a translation is missing. Baseline on a live boot: root PDB entries
are zero (L0 e=0 idx=0) so the writes UVM issues into the level pages
have no parent entry yet.

1 files changed, 1 insertions, 0 deletions

diff --git a/kernel/gsp_sema_service.h b/kernel/gsp_sema_service.h
index f652ffd..e67f0ba 100644
--- a/kernel/gsp_sema_service.h
+++ b/kernel/gsp_sema_service.h
@@ -57,6 +57,7 @@ void gsp_sema_service_vaspace_del(u32 h_vaspace);
 int  gsp_sema_service_start(void);
 void gsp_sema_service_stop(void);
 int  gsp_sema_service_probe(u64 gpu_va, u32 count);
+int  gsp_sema_service_walk_probe(u64 gpu_va);
 int  gsp_sema_service_dump_channels(void);
 int  gsp_sema_service_add_map(u64 gpu_va, u64 pa, u64 len, u32 ap);
 void gsp_sema_service_doorbell(u32 token);