[RFC 14/14] platform: generic: Add PMU support

[Atish Patra]

Add PMU support for generic platform. Generic platform solely relies on
the device tree to parse all pmu related information. If any event is
not described in device tree, generic platform will not support it.

Signed-off-by: Atish Patra <atish.patra at wdc.com>
---
 platform/generic/platform.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/platform/generic/platform.c b/platform/generic/platform.c
index 8c1e06f1244c..03f8bca2cb2d 100644
--- a/platform/generic/platform.c
+++ b/platform/generic/platform.c
@@ -16,6 +16,7 @@
 #include <sbi_utils/fdt/fdt_domain.h>
 #include <sbi_utils/fdt/fdt_fixup.h>
 #include <sbi_utils/fdt/fdt_helper.h>
+#include <sbi_utils/fdt/fdt_pmu.h>
 #include <sbi_utils/irqchip/fdt_irqchip.h>
 #include <sbi_utils/serial/fdt_serial.h>
 #include <sbi_utils/timer/fdt_timer.h>
@@ -204,6 +205,35 @@ static void generic_system_reset(u32 reset_type, u32 reset_reason)
 	fdt_system_reset(reset_type, reset_reason);
 }
 
+static int generic_pmu_init(void)
+{
+	return fdt_pmu_setup(sbi_scratch_thishart_arg1_ptr());
+}
+
+static uint64_t generic_pmu_get_mhpmevent_value(uint32_t event_idx,
+						uint64_t data)
+{
+	uint64_t result = 0;
+
+
+	/* data is valid only for raw events and is equal to event selector */
+	if (event_idx == SBI_PMU_EVENT_RAW_IDX)
+		result = data;
+	else
+		result = fdt_pmu_get_select_value(event_idx);
+
+	/**
+	 * Generic platform follows the SBI specification recommendation to
+	 * compute the mhpmevent value i.e.
+	 * xyz[0:19]    : event_idx
+	 * xyz[20:XLEN] : event_data[0:(XLEN-20)]
+	 */
+	result = result << SBI_PMU_EVENT_IDX_OFFSET |
+		(event_idx & SBI_PMU_EVENT_IDX_MASK);
+
+	return result;
+}
+
 const struct sbi_platform_operations platform_ops = {
 	.early_init		= generic_early_init,
 	.final_init		= generic_final_init,
@@ -219,6 +249,8 @@ const struct sbi_platform_operations platform_ops = {
 	.ipi_clear		= fdt_ipi_clear,
 	.ipi_init		= fdt_ipi_init,
 	.ipi_exit		= fdt_ipi_exit,
+	.pmu_init		= generic_pmu_init,
+	.get_mhpmevent_value    = generic_pmu_get_mhpmevent_value,
 	.get_tlbr_flush_limit	= generic_tlbr_flush_limit,
 	.timer_value		= fdt_timer_value,
 	.timer_event_stop	= fdt_timer_event_stop,
-- 
2.25.1