qcacmn: add support to clear the consumed HW descriptors

Add support to clear/reset the consumed HW descriptors
to zero.

Change-Id: Idccb120afa448c4f958a3177f27cab9b1197ac3e
CRs-Fixed: 2978850

dp/wifi3.0/dp_tx.c

@@ -1562,6 +1562,36 @@ dp_tx_hw_desc_update_evt(uint8_t *hal_tx_desc_cached,
 }
 #endif
 
+#if defined(CLEAR_SW2TCL_CONSUMED_DESC)
+/**
+ * dp_tx_clear_consumed_hw_descs - Reset all the consumed Tx ring descs to 0
+ *
+ * @soc: DP soc handle
+ * @hal_ring_hdl: Source ring pointer
+ *
+ * Return: void
+ */
+static inline
+void dp_tx_clear_consumed_hw_descs(struct dp_soc *soc,
+				   hal_ring_handle_t hal_ring_hdl)
+{
+	void *desc = hal_srng_src_get_next_consumed(soc->hal_soc, hal_ring_hdl);
+
+	while (desc) {
+		hal_tx_desc_clear(desc);
+		desc = hal_srng_src_get_next_consumed(soc->hal_soc,
+						      hal_ring_hdl);
+	}
+}
+
+#else
+static inline
+void dp_tx_clear_consumed_hw_descs(struct dp_soc *soc,
+				   hal_ring_handle_t hal_ring_hdl)
+{
+}
+#endif /* CLEAR_SW2TCL_CONSUMED_DESC */
+
 /**
  * dp_tx_hw_enqueue() - Enqueue to TCL HW for transmit
  * @soc: DP Soc Handle
@@ -1697,6 +1727,8 @@ dp_tx_hw_enqueue(struct dp_soc *soc, struct dp_vdev *vdev,
 		return status;
 	}
 
+	dp_tx_clear_consumed_hw_descs(soc, hal_ring_hdl);
+
 	/* Sync cached descriptor with HW */
 
 	hal_tx_desc = hal_srng_src_get_next(soc->hal_soc, hal_ring_hdl);

hal/wifi3.0/hal_api.h

@@ -1764,6 +1764,48 @@ void hal_get_sw_hptp(void *hal_soc, hal_ring_handle_t hal_ring_hdl,
 	}
 }
 
+#if defined(CLEAR_SW2TCL_CONSUMED_DESC)
+/**
+ * hal_srng_src_get_next_consumed - Get the next desc if consumed by HW
+ *
+ * @hal_soc: Opaque HAL SOC handle
+ * @hal_ring_hdl: Source ring pointer
+ *
+ * Return: pointer to descriptor if consumed by HW, else NULL
+ */
+static inline
+void *hal_srng_src_get_next_consumed(void *hal_soc,
+				     hal_ring_handle_t hal_ring_hdl)
+{
+	struct hal_srng *srng = (struct hal_srng *)hal_ring_hdl;
+	uint32_t *desc = NULL;
+	/* TODO: Using % is expensive, but we have to do this since
+	 * size of some SRNG rings is not power of 2 (due to descriptor
+	 * sizes). Need to create separate API for rings used
+	 * per-packet, with sizes power of 2 (TCL2SW, REO2SW,
+	 * SW2RXDMA and CE rings)
+	 */
+	uint32_t next_entry = (srng->last_desc_cleared + srng->entry_size) %
+			      srng->ring_size;
+
+	if (next_entry != (srng->u.src_ring.cached_tp + srng->entry_size) %
+			  srng->ring_size) {
+		desc = &srng->ring_base_vaddr[next_entry];
+		srng->last_desc_cleared = next_entry;
+	}
+
+	return desc;
+}
+
+#else
+static inline
+void *hal_srng_src_get_next_consumed(void *hal_soc,
+				     hal_ring_handle_t hal_ring_hdl)
+{
+	return NULL;
+}
+#endif /* CLEAR_SW2TCL_CONSUMED_DESC */
+
 /**
  * hal_srng_src_get_next - Get next entry from a source ring and move cached tail pointer
  *

hal/wifi3.0/hal_internal.h

@@ -472,6 +472,10 @@ struct hal_srng {
 	unsigned long srng_event;
 	/* last flushed time stamp */
 	uint64_t last_flush_ts;
+#if defined(CLEAR_SW2TCL_CONSUMED_DESC)
+	/* last ring desc entry cleared */
+	uint32_t last_desc_cleared;
+#endif
 #if defined(FEATURE_HAL_DELAYED_REG_WRITE) || \
 	defined(FEATURE_HAL_DELAYED_REG_WRITE_V2)
 	/* Previous hp/tp (based on ring dir) value written to the reg */

hal/wifi3.0/hal_tx.h

@@ -463,6 +463,19 @@ static inline void hal_tx_desc_set_hlos_tid(void *desc,
 	HAL_SET_FLD(desc, TCL_DATA_CMD_4, HLOS_TID_OVERWRITE) |=
 	   HAL_TX_SM(TCL_DATA_CMD_4, HLOS_TID_OVERWRITE, 1);
 }
+
+/**
+ * hal_tx_desc_clear - Clear the HW descriptor entry
+ * @hw_desc: Hardware descriptor to be cleared
+ *
+ * Return: void
+ */
+static inline void hal_tx_desc_clear(void *hw_desc)
+{
+	qdf_mem_set(hw_desc + sizeof(struct tlv_32_hdr),
+		    HAL_TX_DESC_LEN_BYTES, 0);
+}
+
 /**
  * hal_tx_desc_sync - Commit the descriptor to Hardware
  * @hal_tx_des_cached: Cached descriptor that software maintains