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lib: sbi_pmu: Implement sbi_pmu_counter_fw_read_hi

To support 64 bit firmware counters on RV32 systems, we implement
sbi_pmu_counter_fw_read_hi() which returns the upper 32 bits of
the firmware counter value. On RV64 (or higher) systems, this
function will always return zero.

Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Mayuresh Chitale 1 year ago
parent
commit
51951d9e9a
2 changed files with 9 additions and 0 deletions
  1. 1 0
      include/sbi/sbi_ecall_interface.h
  2. 8 0
      lib/sbi/sbi_ecall_pmu.c

+ 1 - 0
include/sbi/sbi_ecall_interface.h

@@ -101,6 +101,7 @@
 #define SBI_EXT_PMU_COUNTER_START	0x3
 #define SBI_EXT_PMU_COUNTER_STOP	0x4
 #define SBI_EXT_PMU_COUNTER_FW_READ	0x5
+#define SBI_EXT_PMU_COUNTER_FW_READ_HI	0x6
 
 /** General pmu event codes specified in SBI PMU extension */
 enum sbi_pmu_hw_generic_events_t {

+ 8 - 0
lib/sbi/sbi_ecall_pmu.c

@@ -54,6 +54,14 @@ static int sbi_ecall_pmu_handler(unsigned long extid, unsigned long funcid,
 		ret = sbi_pmu_ctr_fw_read(regs->a0, &temp);
 		*out_val = temp;
 		break;
+	case SBI_EXT_PMU_COUNTER_FW_READ_HI:
+#if __riscv_xlen == 32
+		ret = sbi_pmu_ctr_fw_read(regs->a0, &temp);
+		*out_val = temp >> 32;
+#else
+		*out_val = 0;
+#endif
+		break;
 	case SBI_EXT_PMU_COUNTER_START:
 
 #if __riscv_xlen == 32