Add control page variables for PGM.

Currently, PGM token satisfaction is tracked in
userspace. However, Litmus needs to be aware of
when a PGM task is waiting for tokens in order to
avoid unbounded priority inversions. The state of
a PGM task is communicated to Litmus via the
control page.

We should be able to remove control page variables
for PGM if/when token tracking is moved from
userspace into the kernel.

1 files changed, 4 insertions, 0 deletions

diff --git a/include/litmus/rt_param.h b/include/litmus/rt_param.h
index 138799fbaad7..bc074c63c7ad 100644
--- a/include/litmus/rt_param.h
+++ b/include/litmus/rt_param.h
@@ -121,6 +121,10 @@ struct control_page {
         uint64_t irq_syscall_start; /* Snapshot of irq_count when the syscall
                                      * started. */
 
+        /* Flags from userspace signifying PGM wait states. */
+        volatile uint32_t       pgm_waiting;   /* waiting for tokens */
+        volatile uint32_t       pgm_satisfied; /* needed tokens acquired */
+
         /* to be extended */
 };