[v2 2/2] lib: sbi_pmu: Fix the counter info function

[Atish Patra]

The counter info should only return valid hardware counters for the ones
set in the counter mask. Otherwise, it will report incorrect number of
hardware counters to the supervisor if the platform has discontiguous
counters.

Fixes: c744ed77b18c ("lib: sbi_pmu: Enable noncontigous hpm event and counters")

Signed-off-by: Atish Patra <atishp at rivosinc.com>
---
 include/sbi/sbi_pmu.h | 1 +
 lib/sbi/sbi_pmu.c     | 8 ++++++--
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/include/sbi/sbi_pmu.h b/include/sbi/sbi_pmu.h
index 16f687733baa..bd0392e5fe5a 100644
--- a/include/sbi/sbi_pmu.h
+++ b/include/sbi/sbi_pmu.h
@@ -23,6 +23,7 @@ struct sbi_scratch;
 #define SBI_PMU_HW_CTR_MAX 32
 #define SBI_PMU_CTR_MAX	   (SBI_PMU_HW_CTR_MAX + SBI_PMU_FW_CTR_MAX)
 #define SBI_PMU_FIXED_CTR_MASK 0x07
+#define SBI_PMU_CY_IR_MASK	0x05
 
 struct sbi_pmu_device {
 	/** Name of the PMU platform device */
diff --git a/lib/sbi/sbi_pmu.c b/lib/sbi/sbi_pmu.c
index 1ac8562a9c99..3f1d1dda24fc 100644
--- a/lib/sbi/sbi_pmu.c
+++ b/lib/sbi/sbi_pmu.c
@@ -891,13 +891,17 @@ int sbi_pmu_ctr_get_info(uint32_t cidx, unsigned long *ctr_info)
 	int width;
 	union sbi_pmu_ctr_info cinfo = {0};
 	struct sbi_scratch *scratch = sbi_scratch_thishart_ptr();
+	unsigned long counter_mask = (unsigned long)sbi_hart_mhpm_mask(scratch) |
+				     SBI_PMU_CY_IR_MASK;
 
-	/* Sanity check. Counter1 is not mapped at all */
-	if (cidx >= total_ctrs || cidx == 1)
+	/* Sanity check */
+	if (cidx >= total_ctrs)
 		return SBI_EINVAL;
 
 	/* We have 31 HW counters with 31 being the last index(MHPMCOUNTER31) */
 	if (cidx < num_hw_ctrs) {
+		if (!(__test_bit(cidx, &counter_mask)))
+			return SBI_EINVAL;
 		cinfo.type = SBI_PMU_CTR_TYPE_HW;
 		cinfo.csr = CSR_CYCLE + cidx;
 		/* mcycle & minstret are always 64 bit */
-- 
2.34.1