qcacmn: Fix long ping delay after enable RTPM

Issue1: Driver RTPM state is ON/NONE, Kernel state is RESUMING.
cdp_runtime_resume is already complete,
hif_pm_runtime_get return -E_INPROGRESS,
dp_tx_hw_enqueue will set the flush event,
but cdp_runtime_resume is already done,
this flush event will be handled only on next pkt tx.

Issue2: Driver RTPM state: Resuming
hif_pm_runtime_get returns -EBUSY,
dp_tx_hw_enqueue is interrupted by any IRQ,
cdp_runtime_resume is completed,
dp_tx_hw_enqueue will set the flush event,
This flush event will be handled only on next pkt tx.

Fix:
Introduce a link_state_up atomic variable in hif to track the link state
change by pld_cb.
Set atomic variable link_state_up=1 in pmo_core_psoc_bus_runtime_resume
just after pld_cb. pld_cb brings the PCIe bus out of suspend state.
Set atomic variable link_state_up=0 in pmo_core_psoc_bus_runtime_suspend
just before pld_cb. pld_cb puts the PCIe bus into suspend state.

Introduce dp_runtime_get and dp_runtime_put.
dp_runtime_get get refcount with increment of an atomic variable.
dp_runtime_put return refcount with decrement of  this atomic variable.

If hif_pm_runtime_get returns -EBUSY or -EINPROGRESS,
take the dp runtime refcount using dp_runtime_get,
check if the link state is up, write TX ring HP,
return the dp runtime refcount using dp_runtime_put.

cdp_runtime_suspend should reject the suspend, if dp_runtime_get is non
zero.
cdp_runtime_resume should wait until dp_runtime_get becomes zero or time
out, then flush pending tx for runtime suspend.

Change-Id: I5b97d50cba710082f117f3845f7830712b86cda7
CRs-Fixed: 2844888

dp/wifi3.0/dp_internal.h

@@ -2633,4 +2633,73 @@ void dp_desc_multi_pages_mem_free(struct dp_soc *soc,
 }
 #endif
 
+#ifdef FEATURE_RUNTIME_PM
+/**
+ * dp_runtime_get() - Get dp runtime refcount
+ * @soc: Datapath soc handle
+ *
+ * Get dp runtime refcount by increment of an atomic variable, which can block
+ * dp runtime resume to wait to flush pending tx by runtime suspend.
+ *
+ * Return: Current refcount
+ */
+static inline int32_t dp_runtime_get(struct dp_soc *soc)
+{
+	return qdf_atomic_inc_return(&soc->dp_runtime_refcount);
+}
+
+/**
+ * dp_runtime_put() - Return dp runtime refcount
+ * @soc: Datapath soc handle
+ *
+ * Return dp runtime refcount by decrement of an atomic variable, allow dp
+ * runtime resume finish.
+ *
+ * Return: Current refcount
+ */
+static inline int32_t dp_runtime_put(struct dp_soc *soc)
+{
+	return qdf_atomic_dec_return(&soc->dp_runtime_refcount);
+}
+
+/**
+ * dp_runtime_get_refcount() - Get dp runtime refcount
+ * @soc: Datapath soc handle
+ *
+ * Get dp runtime refcount by returning an atomic variable
+ *
+ * Return: Current refcount
+ */
+static inline int32_t dp_runtime_get_refcount(struct dp_soc *soc)
+{
+	return qdf_atomic_read(&soc->dp_runtime_refcount);
+}
+
+/**
+ * dp_runtime_init() - Init dp runtime refcount when dp soc init
+ * @soc: Datapath soc handle
+ *
+ * Return: QDF_STATUS
+ */
+static inline QDF_STATUS dp_runtime_init(struct dp_soc *soc)
+{
+	return qdf_atomic_init(&soc->dp_runtime_refcount);
+}
+#else
+static inline int32_t dp_runtime_get(struct dp_soc *soc)
+{
+	return 0;
+}
+
+static inline int32_t dp_runtime_put(struct dp_soc *soc)
+{
+	return 0;
+}
+
+static inline QDF_STATUS dp_runtime_init(struct dp_soc *soc)
+{
+	return QDF_STATUS_SUCCESS;
+}
+#endif
+
 #endif /* #ifndef _DP_INTERNAL_H_ */