[RFC 2/9] drivers/perf: riscv: Add a flag to indicate SBI v2.0 support

[Atish Patra]

SBI v2.0 added few functions to improve SBI PMU extension. In order
to be backward compatible, the driver must use these functions only
if SBI v2.0 is available.

Signed-off-by: Atish Patra <atishp at rivosinc.com>
---
 drivers/perf/riscv_pmu_sbi.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c
index 16acd4dcdb96..40a335350d08 100644
--- a/drivers/perf/riscv_pmu_sbi.c
+++ b/drivers/perf/riscv_pmu_sbi.c
@@ -35,6 +35,8 @@
 PMU_FORMAT_ATTR(event, "config:0-47");
 PMU_FORMAT_ATTR(firmware, "config:63");
 
+static bool sbi_v2_available;
+
 static struct attribute *riscv_arch_formats_attr[] = {
 	&format_attr_event.attr,
 	&format_attr_firmware.attr,
@@ -1108,6 +1110,9 @@ static int __init pmu_sbi_devinit(void)
 		return 0;
 	}
 
+	if (sbi_spec_version >= sbi_mk_version(2, 0))
+		sbi_v2_available = true;
+
 	ret = cpuhp_setup_state_multi(CPUHP_AP_PERF_RISCV_STARTING,
 				      "perf/riscv/pmu:starting",
 				      pmu_sbi_starting_cpu, pmu_sbi_dying_cpu);
-- 
2.34.1