[RFC PATCH v2 4/4] lib: sbi: add SBI_EXT_PMU_IRQ_CLEAR

[Clément Léger]

Now that we have sse support for such interrupt, the IRQ can only be
cleared by the SBI. In some cases in S-mode OS, it might be needed to
clear the pending IRQ. Add SBI_EXT_PMU_IRQ_CLEAR ecall to clear such
IRQ.

NOTE: this is temporary until the counter delegation support from Atish
lands in Linux/OpenSBI.

Signed-off-by: Clément Léger <cleger at rivosinc.com>
---
 include/sbi/sbi_ecall_interface.h | 1 +
 include/sbi/sbi_pmu.h             | 2 ++
 lib/sbi/sbi_ecall_pmu.c           | 3 +++
 3 files changed, 6 insertions(+)

diff --git a/include/sbi/sbi_ecall_interface.h b/include/sbi/sbi_ecall_interface.h
index a5f3edf..3815b42 100644
--- a/include/sbi/sbi_ecall_interface.h
+++ b/include/sbi/sbi_ecall_interface.h
@@ -105,6 +105,7 @@
 #define SBI_EXT_PMU_COUNTER_FW_READ	0x5
 #define SBI_EXT_PMU_COUNTER_FW_READ_HI	0x6
 #define SBI_EXT_PMU_SNAPSHOT_SET_SHMEM	0x7
+#define SBI_EXT_PMU_IRQ_CLEAR		0x8
 
 /** General pmu event codes specified in SBI PMU extension */
 enum sbi_pmu_hw_generic_events_t {
diff --git a/include/sbi/sbi_pmu.h b/include/sbi/sbi_pmu.h
index c5b4e51..6bed6c9 100644
--- a/include/sbi/sbi_pmu.h
+++ b/include/sbi/sbi_pmu.h
@@ -153,4 +153,6 @@ int sbi_pmu_ctr_incr_fw(enum sbi_pmu_fw_event_code_id fw_id);
 
 void sbi_pmu_ovf_irq(struct sbi_trap_regs *regs);
 
+void sbi_pmu_irq_clear(void);
+
 #endif
diff --git a/lib/sbi/sbi_ecall_pmu.c b/lib/sbi/sbi_ecall_pmu.c
index 40a63a6..5b55eb5 100644
--- a/lib/sbi/sbi_ecall_pmu.c
+++ b/lib/sbi/sbi_ecall_pmu.c
@@ -73,6 +73,9 @@ static int sbi_ecall_pmu_handler(unsigned long extid, unsigned long funcid,
 	case SBI_EXT_PMU_COUNTER_STOP:
 		ret = sbi_pmu_ctr_stop(regs->a0, regs->a1, regs->a2);
 		break;
+	case SBI_EXT_PMU_IRQ_CLEAR:
+		sbi_pmu_irq_clear();
+		break;
 	case SBI_EXT_PMU_SNAPSHOT_SET_SHMEM:
 		/* fallthrough as OpenSBI doesn't support snapshot yet */
 	default:
-- 
2.43.0