[PATCH] platform: openpiton: Add PMU initialization

Manuel Hernández Méndez maherme.dev at gmail.com
Mon Jul 21 09:09:20 PDT 2025


The OpenPiton framework has a generic PMU that is not used by OpenSBI.
Due to OpenSBI’s build system we cannot directly reuse the generic
platform functions, so simply copy them to the OpenPiton platform.

Signed-off-by: Manuel Hernández Méndez <maherme.dev at gmail.com>
---
 platform/fpga/openpiton/platform.c | 39 ++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/platform/fpga/openpiton/platform.c b/platform/fpga/openpiton/platform.c
index d2cf3e32..08136859 100644
--- a/platform/fpga/openpiton/platform.c
+++ b/platform/fpga/openpiton/platform.c
@@ -11,6 +11,7 @@
 #include <sbi/sbi_platform.h>
 #include <sbi_utils/fdt/fdt_helper.h>
 #include <sbi_utils/fdt/fdt_fixup.h>
+#include <sbi_utils/fdt/fdt_pmu.h>
 #include <sbi_utils/ipi/aclint_mswi.h>
 #include <sbi_utils/irqchip/plic.h>
 #include <sbi_utils/serial/uart8250.h>
@@ -156,6 +157,42 @@ static int openpiton_timer_init(void)
 	return aclint_mtimer_cold_init(&mtimer, NULL);
 }
 
+/*
+ * Initialize openpiton pmu during cold boot.
+ */
+int openpiton_pmu_init(void)
+{
+	int rc;
+
+	rc = fdt_pmu_setup(fdt_get_address());
+	if (rc && rc != SBI_ENOENT)
+		return rc;
+
+	return 0;
+}
+
+uint64_t openpiton_pmu_xlate_to_mhpmevent(uint32_t event_idx, uint64_t data)
+{
+	uint64_t evt_val = 0;
+
+	/* data is valid only for raw events and is equal to event selector */
+	if (event_idx == SBI_PMU_EVENT_RAW_IDX ||
+		event_idx == SBI_PMU_EVENT_RAW_V2_IDX)
+		evt_val = data;
+	else {
+		/**
+		 * Generic platform follows the SBI specification recommendation
+		 * i.e. zero extended event_idx is used as mhpmevent value for
+		 * hardware general/cache events if platform does't define one.
+		 */
+		evt_val = fdt_pmu_get_select_value(event_idx);
+		if (!evt_val)
+			evt_val = (uint64_t)event_idx;
+	}
+
+	return evt_val;
+}
+
 /*
  * Platform descriptor.
  */
@@ -165,6 +202,8 @@ const struct sbi_platform_operations platform_ops = {
 	.irqchip_init = openpiton_irqchip_init,
 	.ipi_init = openpiton_ipi_init,
 	.timer_init = openpiton_timer_init,
+	.pmu_init = openpiton_pmu_init,
+	.pmu_xlate_to_mhpmevent = openpiton_pmu_xlate_to_mhpmevent,
 };
 
 const struct sbi_platform platform = {
-- 
2.34.1




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