vgsp: m113 - re-register the VAS page directory after planting data (re-commit probe)

All late engine-tree writes are invisible to the SM walker (only the
commit-time snapshot resolves); the mail injection at a main-window fresh
slot also fails (m112). Probe whether UNSET+SET_PAGE_DIRECTORY on the
ladder VAS after planting forces the server walker to re-snapshot the tree;
gated by gr_recommit.

1 files changed, 18 insertions, 0 deletions

diff --git a/kernel/gsp_phys_gpu.c b/kernel/gsp_phys_gpu.c
index e92e5f1..c5419a5 100644
--- a/kernel/gsp_phys_gpu.c
+++ b/kernel/gsp_phys_gpu.c
@@ -1050,6 +1050,24 @@ int gsp_phys_rmcall_gr_data_prewin_value(void)
 EXPORT_SYMBOL_GPL(gsp_phys_rmcall_gr_data_prewin_value);
 
 /*
+ * m113: after planting the launch's data mappings, re-register the VAS page
+ * directory (UNSET+SET) to force the server walker to re-snapshot the tree;
+ * all evidence says the SM walker resolves only the commit-time tree, and
+ * late writes (leaf or table) are invisible. Default 0.
+ */
+static int gsp_phys_rmcall_gr_recommit_param;
+module_param_named(gsp_phys_rmcall_gr_recommit,
+		   gsp_phys_rmcall_gr_recommit_param, int, 0644);
+MODULE_PARM_DESC(gsp_phys_rmcall_gr_recommit,
+		 "Re-register the VAS page directory after planting data (default 0)");
+
+int gsp_phys_rmcall_gr_recommit_value(void)
+{
+	return gsp_phys_rmcall_gr_recommit_param;
+}
+EXPORT_SYMBOL_GPL(gsp_phys_rmcall_gr_recommit_value);
+
+/*
  * m95: program each GPC's MMU_CTRL from the hub's PFB MMU_CTRL (the real RM's
  * grInitGPCMmuPRIRegs matching-fields copy) before a forwarded launch. The
  * GPC-side walker refuses the SM I-fetch with MMU_NACK while hub-side reads