[dv] New directed test to cover some scenarios with U-mode execution

This directly stimulates cases where U-mode execution is attempted against locked regions (and a region with no permissions).
lowRISC · Jun 23, 2023 · fbd070c · fbd070c
1 parent 4e17587
commit fbd070c
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Showing 4 changed files with 448 additions and 359 deletions.
diff --git a/dv/uvm/core_ibex/directed_tests/custom_macros.h b/dv/uvm/core_ibex/directed_tests/custom_macros.h
@@ -113,6 +113,10 @@
   lw s1, 0(s2);                               \
   sw s1, 0(s2);
 
+// This assumes a PMP access failure on the read and write where the handler
+// jumps back to the failing access in M mode. If the access succeeds it remains
+// in U mode and the second SWITCH_TO_U_MODE will trap (due to attempting a
+// write to mstatus).
 #define RW_ACCESSES_IN_U_MODE(pmp_addr, gran) \
   la s0, pmp_addr;                            \
   SWITCH_TO_U_MODE_LABEL(1f);                 \