net: thunderx: Fix for Qset error due to CQ full

[ Upstream commit 4c0b6eaf373a5323f03a3a20c42fc435715b073d ]

On Thunderx pass 1.x and pass2 due to a HW errata default CQ
DROP_LEVEL of 0x80 is not sufficient to avoid CQ_WR_FULL Qset
error when packets are being received at >20Mpps resulting in
complete stall of packet reception.

This patch will configure it to 0x100 which is what is expected
by HW on Thunderx. On future passes of thunderx and other chips
HW default/reset value will be 0x100 or higher hence not overwritten.

Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/ethernet/cavium/thunder/nic.h b/drivers/net/ethernet/cavium/thunder/nic.h
index 39ca6744a4e68fe317f93e1318e729509c1b978e..22471d283a952ad6b43115badf339acd3a0c3418 100644 (file)
--- a/drivers/net/ethernet/cavium/thunder/nic.h
+++ b/drivers/net/ethernet/cavium/thunder/nic.h
@@ -116,6 +116,15 @@
 #define NIC_PF_INTR_ID_MBOX0           8
 #define NIC_PF_INTR_ID_MBOX1           9
 
+/* Minimum FIFO level before all packets for the CQ are dropped
+ *
+ * This value ensures that once a packet has been "accepted"
+ * for reception it will not get dropped due to non-availability
+ * of CQ descriptor. An errata in HW mandates this value to be
+ * atleast 0x100.
+ */
+#define NICPF_CQM_MIN_DROP_LEVEL       0x100
+
 /* Global timer for CQ timer thresh interrupts
  * Calculated for SCLK of 700Mhz
  * value written should be a 1/16th of what is expected

diff --git a/drivers/net/ethernet/cavium/thunder/nic_main.c b/drivers/net/ethernet/cavium/thunder/nic_main.c
index 5f24d11cb16aad5ae6bd474d538053ac6465c868..16baaafed26c31523f61b43684d28c2c4a648544 100644 (file)
--- a/drivers/net/ethernet/cavium/thunder/nic_main.c
+++ b/drivers/net/ethernet/cavium/thunder/nic_main.c
@@ -309,6 +309,7 @@ static void nic_set_lmac_vf_mapping(struct nicpf *nic)
 static void nic_init_hw(struct nicpf *nic)
 {
        int i;
+       u64 cqm_cfg;
 
        /* Enable NIC HW block */
        nic_reg_write(nic, NIC_PF_CFG, 0x3);
@@ -345,6 +346,11 @@ static void nic_init_hw(struct nicpf *nic)
        /* Enable VLAN ethertype matching and stripping */
        nic_reg_write(nic, NIC_PF_RX_ETYPE_0_7,
                      (2 << 19) | (ETYPE_ALG_VLAN_STRIP << 16) | ETH_P_8021Q);
+
+       /* Check if HW expected value is higher (could be in future chips) */
+       cqm_cfg = nic_reg_read(nic, NIC_PF_CQM_CFG);
+       if (cqm_cfg < NICPF_CQM_MIN_DROP_LEVEL)
+               nic_reg_write(nic, NIC_PF_CQM_CFG, NICPF_CQM_MIN_DROP_LEVEL);
 }
 
 /* Channel parse index configuration */

diff --git a/drivers/net/ethernet/cavium/thunder/nic_reg.h b/drivers/net/ethernet/cavium/thunder/nic_reg.h
index dd536be20193119c3465cd772a4bff6d649e3319..afb10e326b4fc46043b4d3f4cddb7d17f1cc341c 100644 (file)
--- a/drivers/net/ethernet/cavium/thunder/nic_reg.h
+++ b/drivers/net/ethernet/cavium/thunder/nic_reg.h
@@ -21,7 +21,7 @@
 #define   NIC_PF_TCP_TIMER                     (0x0060)
 #define   NIC_PF_BP_CFG                                (0x0080)
 #define   NIC_PF_RRM_CFG                       (0x0088)
-#define   NIC_PF_CQM_CF                                (0x00A0)
+#define   NIC_PF_CQM_CFG                       (0x00A0)
 #define   NIC_PF_CNM_CF                                (0x00A8)
 #define   NIC_PF_CNM_STATUS                    (0x00B0)
 #define   NIC_PF_CQ_AVG_CFG                    (0x00C0)