drivers/perf: hisi_pcie: Introduce hisi_pcie_pmu_get_event_ctrl_val()

Factor out retrieving of the register value for the
corresponding event from hisi_pcie_config_event_ctrl() into a
new function hisi_pcie_pmu_get_event_ctrl_val() allowing future
reuse.
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20240223103359.18669-3-yangyicong@huawei.comSigned-off-by: Will Deacon <will@kernel.org>

drivers/perf/hisilicon/hisi_pcie_pmu.c

@@ -216,10 +216,8 @@ static void hisi_pcie_pmu_writeq(struct hisi_pcie_pmu *pcie_pmu, u32 reg_offset,
 	writeq_relaxed(val, pcie_pmu->base + offset);
 }
 
-static void hisi_pcie_pmu_config_event_ctrl(struct perf_event *event)
+static u64 hisi_pcie_pmu_get_event_ctrl_val(struct perf_event *event)
 {
-	struct hisi_pcie_pmu *pcie_pmu = to_pcie_pmu(event->pmu);
-	struct hw_perf_event *hwc = &event->hw;
 	u64 port, trig_len, thr_len, len_mode;
 	u64 reg = HISI_PCIE_INIT_SET;
 
@@ -256,6 +254,15 @@ static void hisi_pcie_pmu_config_event_ctrl(struct perf_event *event)
 	else
 		reg |= FIELD_PREP(HISI_PCIE_LEN_M, HISI_PCIE_LEN_M_DEFAULT);
 
+	return reg;
+}
+
+static void hisi_pcie_pmu_config_event_ctrl(struct perf_event *event)
+{
+	struct hisi_pcie_pmu *pcie_pmu = to_pcie_pmu(event->pmu);
+	struct hw_perf_event *hwc = &event->hw;
+	u64 reg = hisi_pcie_pmu_get_event_ctrl_val(event);
+
 	hisi_pcie_pmu_writeq(pcie_pmu, HISI_PCIE_EVENT_CTRL, hwc->idx, reg);
 }