csr_write(CSR_MSTATUS, mstatus_val);
- /* Enable user/supervisor use of perf counters */
+ /* Disable user mode usage of all perf counters except default ones (CY, TM, IR) */
if (misa_extension('S') &&
sbi_hart_has_feature(scratch, SBI_HART_HAS_SCOUNTEREN))
- csr_write(CSR_SCOUNTEREN, -1);
- if (sbi_hart_has_feature(scratch, SBI_HART_HAS_MCOUNTEREN))
- csr_write(CSR_MCOUNTEREN, -1);
+ csr_write(CSR_SCOUNTEREN, 7);
+
+ if (sbi_hart_has_feature(scratch, SBI_HART_HAS_MCOUNTEREN)) {
+ if (sbi_hart_has_feature(scratch, SBI_HART_HAS_MCOUNTINHIBIT))
+ /**
+ * Just enable the default counters (CY, TM, IR) because
+ * some OS (e.g FreeBSD) expect them to be enabled.
+ *
+ * All other counters will be enabled at runtime after
+ * S-mode request.
+ */
+ csr_write(CSR_MCOUNTEREN, 7);
+ else
+ /* Supervisor mode usage are enabled by default */
+ csr_write(CSR_MCOUNTEREN, -1);
+ }
+
+ /* All programmable counters will start running at runtime after S-mode request */
+ if (sbi_hart_has_feature(scratch, SBI_HART_HAS_MCOUNTINHIBIT))
+ csr_write(CSR_MCOUNTINHIBIT, 0xFFFFFFF8);
/* Disable all interrupts */
csr_write(CSR_MIE, 0);