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| author | Shay Aviv <shay.aviv@gmail.com> | 2021-06-09 23:15:09 +0300 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2021-06-09 13:15:09 -0700 |
| commit | 1908fc380c24ef0989063e8029eaa14913c187dd (patch) | |
| tree | cb447cd78f78935bb6daa11456610706285ba4af | |
| parent | 0e4b5cbc25e27ccb8e7a1bebf08111c0f5e9bebe (diff) | |
| download | spike-1908fc380c24ef0989063e8029eaa14913c187dd.zip spike-1908fc380c24ef0989063e8029eaa14913c187dd.tar.gz spike-1908fc380c24ef0989063e8029eaa14913c187dd.tar.bz2 | |
Apply scounteren only if S-mode is supported (#726)
When U-mode is enabled but S-mode is disabled, `mcounteren` should control the availability of the hardware performance-monitoring counters in U-mode, and `scounteren` should be ignored.
The current implementation (incorrectly) raises an illegal instruction trap when reading performance-monitoring counters in U-mode while S-mode is disabled, even if the counters are enabled in `mcounteren`.
| -rw-r--r-- | riscv/processor.cc | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/riscv/processor.cc b/riscv/processor.cc index 9b6fe12..6225a92 100644 --- a/riscv/processor.cc +++ b/riscv/processor.cc @@ -1405,7 +1405,7 @@ reg_t processor_t::get_csr(int which, insn_t insn, bool write, bool peek) uint32_t ctr_en = -1; if (state.prv < PRV_M) ctr_en &= state.mcounteren; - if (state.prv < PRV_S) + if (supports_extension('S') && state.prv < PRV_S) ctr_en &= state.scounteren; bool ctr_ok = (ctr_en >> (which & 31)) & 1; if (state.v) |