[PATCH v2 05/15] net/nfp: remove pessimistic limit

[Jin Liu <jin.liu@corigine.com>]

Multiple writes cause intermediate pointer values that do not
end on complete TX descriptors.

The QCP peripheral on the NFP provides a number of access
modes. In some access modes, the maximum amount to add must
be restricted to a 6bit value. The particular access mode
used by _nfp_qcp_ptr_add() has no such restrictions, so the
"NFP_QCP_MAX_ADD" test is unnecessary.

Note that trying to add more that the configured ring size
in a single add will cause a QCP overflow, caught and handled
by the QCP peripheral.

Signed-off-by: Jin Liu <jin.liu@corigine.com>
Signed-off-by: Yinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: Chaoyong He <chaoyong.he@corigine.com>
Signed-off-by: Niklas Söderlund <niklas.soderlund@corigine.com>
---
 drivers/net/nfp/nfp_common.h | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/drivers/net/nfp/nfp_common.h b/drivers/net/nfp/nfp_common.h
index 8db5ec23f8..49d6bb6ad5 100644
--- a/drivers/net/nfp/nfp_common.h
+++ b/drivers/net/nfp/nfp_common.h
@@ -44,9 +44,6 @@ struct nfp_net_adapter;
 /* The offset of the queue controller queues in the PCIe Target */
 #define NFP_PCIE_QUEUE(_q) (0x80000 + (NFP_QCP_QUEUE_ADDR_SZ * ((_q) & 0xff)))
 
-/* Maximum value which can be added to a queue with one transaction */
-#define NFP_QCP_MAX_ADD	0x7f
-
 /* Interrupt definitions */
 #define NFP_NET_IRQ_LSC_IDX             0
 
@@ -307,8 +304,6 @@ nn_cfg_writeq(struct nfp_net_hw *hw, int off, uint64_t val)
  * @q: Base address for queue structure
  * @ptr: Add to the Read or Write pointer
  * @val: Value to add to the queue pointer
- *
- * If @val is greater than @NFP_QCP_MAX_ADD multiple writes are performed.
  */
 static inline void
 nfp_qcp_ptr_add(uint8_t *q, enum nfp_qcp_ptr ptr, uint32_t val)
@@ -320,12 +315,7 @@ nfp_qcp_ptr_add(uint8_t *q, enum nfp_qcp_ptr ptr, uint32_t val)
 	else
 		off = NFP_QCP_QUEUE_ADD_WPTR;
 
-	while (val > NFP_QCP_MAX_ADD) {
-		nn_writel(rte_cpu_to_le_32(NFP_QCP_MAX_ADD), q + off);
-		val -= NFP_QCP_MAX_ADD;
-}
-
-nn_writel(rte_cpu_to_le_32(val), q + off);
+	nn_writel(rte_cpu_to_le_32(val), q + off);
 }
 
 /*
-- 
2.27.0