PMP risc-v benchmark fails with page fault

Created by: Moschn

The official riscv-tests have recently been updated to automatically detect the granularity of the underlying implementation and it would be nice to add them to our CI. However, the PMP benchmark fails with a page fault and AFAIK is unrelated to PMP (Note that this report is based on #537 and #523). If the INLINE keyword is removed from the function test_one the benchmark/test successfully completes. See patch below:

diff --git a/benchmarks/pmp/pmp.c b/benchmarks/pmp/pmp.c
index ec07e4a..4a7fbd4 100644
--- a/benchmarks/pmp/pmp.c
+++ b/benchmarks/pmp/pmp.c
@@ -17,8 +17,11 @@ uintptr_t handle_trap(uintptr_t cause, uintptr_t epc, uintptr_t regs[32])
   if (cause == CAUSE_ILLEGAL_INSTRUCTION)
     exit(0); // no PMP support

-  if (!trap_expected || cause != CAUSE_LOAD_ACCESS)
+  if (!trap_expected || cause != CAUSE_LOAD_ACCESS) {
+    printf("trap expected: %d\n", trap_expected);
+    printf("cause: %d, mtval: %p\n", cause, read_csr(mtval));
     exit(1);
+  }
   trap_expected = 0;
   return epc + insn_len(epc);
 }
@@ -97,6 +100,7 @@ INLINE int pmp_ok(pmpcfg_t p, uintptr_t addr, uintptr_t size)
   return hits == 0 || hits >= size;
 }

+// Remove INLINE here and it will work
 INLINE void test_one(uintptr_t addr, uintptr_t size)
 {
   uintptr_t new_mstatus = (read_csr(mstatus) & ~MSTATUS_MPP) | (MSTATUS_MPP & (MSTATUS_MPP >> 1)) | MSTATUS_MPRV;

The output from verilator:

This emulator compiled with JTAG Remote Bitbang client. To enable, use +jtag_rbb_enable=1.
Listening on port 41709
trap expected: 0
cause: 13, mtval: 0x80002dac
*** FAILED *** (tohost = 1)
../orig/riscv-tests/benchmarks/pmp.riscv *** FAILED *** (code = 1) after 370946 cycles

I could not figure out why it fails yet (and I am hoping someone with more experience takes over ;) ).