Merge branch 'gianfar-next'

Claudiu Manoil says:

====================
gianfar: Tx timeout issue

There's an older Tx timeout issue showing up on etsec2 devices
with 2 CPUs.  I pinned this issue down to processing overhead
incurred by supporting multiple Tx/Rx rings, as explained in
the 2nd patch below.  But before this, there's also a concurency
issue leading to Rx/Tx spurrious interrupts, addressed by the
'Tx NAPI' patch below.
The Tx timeout can be triggered with multiple Tx flows,
'iperf -c -N 8' commands, on a 2 CPUs etsec2 based (P1020) board.

Before the patches:
"""
root@p1020rdb-pc:~# iperf -c 172.16.1.3 -n 1000M -P 8 &
[...]
root@p1020rdb-pc:~# NETDEV WATCHDOG: eth1 (fsl-gianfar): transmit queue 1 timed out
WARNING: at net/sched/sch_generic.c:279
Modules linked in:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.13.0-rc3-03386-g89ea59c #23
task: ed84ef40 ti: ed868000 task.ti: ed868000
NIP: c04627a8 LR: c04627a8 CTR: c02fb270
REGS: ed869d00 TRAP: 0700   Not tainted  (3.13.0-rc3-03386-g89ea59c)
MSR: 00029000 <CE,EE,ME>  CR: 44000022  XER: 20000000
[...]

root@p1020rdb-pc:~# [ ID] Interval       Transfer     Bandwidth
[  5]  0.0-19.3 sec  1000 MBytes    434 Mbits/sec
[  8]  0.0-39.7 sec  1000 MBytes    211 Mbits/sec
[  9]  0.0-40.1 sec  1000 MBytes    209 Mbits/sec
[  3]  0.0-40.2 sec  1000 MBytes    209 Mbits/sec
[ 10]  0.0-59.0 sec  1000 MBytes    142 Mbits/sec
[  7]  0.0-74.6 sec  1000 MBytes    112 Mbits/sec
[  6]  0.0-74.7 sec  1000 MBytes    112 Mbits/sec
[  4]  0.0-74.7 sec  1000 MBytes    112 Mbits/sec
[SUM]  0.0-74.7 sec  7.81 GBytes    898 Mbits/sec

root@p1020rdb-pc:~# ifconfig eth1
eth1      Link encap:Ethernet  HWaddr 00:04:9f:00:13:01
          inet addr:172.16.1.1  Bcast:172.16.255.255  Mask:255.255.0.0
          inet6 addr: fe80::204:9fff:fe00:1301/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:708722 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8717849 errors:6 dropped:0 overruns:1470 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:58118018 (55.4 MiB)  TX bytes:274069482 (261.3 MiB)
          Base address:0xa000

"""

After applying the patches:
"""
root@p1020rdb-pc:~# iperf -c 172.16.1.3 -n 1000M -P 8 &
[...]
root@p1020rdb-pc:~# [ ID] Interval       Transfer     Bandwidth
[  9]  0.0-70.5 sec  1000 MBytes    119 Mbits/sec
[  5]  0.0-70.5 sec  1000 MBytes    119 Mbits/sec
[  6]  0.0-70.7 sec  1000 MBytes    119 Mbits/sec
[  4]  0.0-71.0 sec  1000 MBytes    118 Mbits/sec
[  8]  0.0-71.1 sec  1000 MBytes    118 Mbits/sec
[  3]  0.0-71.2 sec  1000 MBytes    118 Mbits/sec
[ 10]  0.0-71.3 sec  1000 MBytes    118 Mbits/sec
[  7]  0.0-71.3 sec  1000 MBytes    118 Mbits/sec
[SUM]  0.0-71.3 sec  7.81 GBytes    942 Mbits/sec

root@p1020rdb-pc:~# ifconfig eth1
eth1      Link encap:Ethernet  HWaddr 00:04:9f:00:13:01
          inet addr:172.16.1.1  Bcast:172.16.255.255  Mask:255.255.0.0
          inet6 addr: fe80::204:9fff:fe00:1301/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:728446 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8690057 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:59732650 (56.9 MiB)  TX bytes:271554306 (258.9 MiB)
          Base address:0xa000
"""
v2: PATCH 2:
    Replaced CPP check with run-time condition to
    limit the number of queues. Updated comments.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/gianfar.h

@@ -377,8 +377,11 @@ extern const char gfar_driver_version[];
 		IMASK_RXFEN0 | IMASK_BSY | IMASK_EBERR | IMASK_BABR | \
 		IMASK_XFUN | IMASK_RXC | IMASK_BABT | IMASK_DPE \
 		| IMASK_PERR)
-#define IMASK_RTX_DISABLED ((~(IMASK_RXFEN0 | IMASK_TXFEN | IMASK_BSY)) \
-			   & IMASK_DEFAULT)
+#define IMASK_RX_DEFAULT (IMASK_RXFEN0 | IMASK_BSY)
+#define IMASK_TX_DEFAULT (IMASK_TXFEN | IMASK_TXBEN)
+
+#define IMASK_RX_DISABLED ((~(IMASK_RX_DEFAULT)) & IMASK_DEFAULT)
+#define IMASK_TX_DISABLED ((~(IMASK_TX_DEFAULT)) & IMASK_DEFAULT)
 
 /* Fifo management */
 #define FIFO_TX_THR_MASK	0x01ff
@@ -409,7 +412,9 @@ extern const char gfar_driver_version[];
 
 /* This default RIR value directly corresponds
  * to the 3-bit hash value generated */
-#define DEFAULT_RIR0	0x05397700
+#define DEFAULT_8RXQ_RIR0	0x05397700
+/* Map even hash values to Q0, and odd ones to Q1 */
+#define DEFAULT_2RXQ_RIR0	0x04104100
 
 /* RQFCR register bits */
 #define RQFCR_GPI		0x80000000
@@ -904,6 +909,22 @@ enum {
 	MQ_MG_MODE
 };
 
+/* GFAR_SQ_POLLING: Single Queue NAPI polling mode
+ *	The driver supports a single pair of RX/Tx queues
+ *	per interrupt group (Rx/Tx int line). MQ_MG mode
+ *	devices have 2 interrupt groups, so the device will
+ *	have a total of 2 Tx and 2 Rx queues in this case.
+ * GFAR_MQ_POLLING: Multi Queue NAPI polling mode
+ *	The driver supports all the 8 Rx and Tx HW queues
+ *	each queue mapped by the Device Tree to one of
+ *	the 2 interrupt groups. This mode implies significant
+ *	processing overhead (CPU and controller level).
+ */
+enum gfar_poll_mode {
+	GFAR_SQ_POLLING = 0,
+	GFAR_MQ_POLLING
+};
+
 /*
  * Per TX queue stats
  */
@@ -1013,17 +1034,20 @@ struct gfar_irqinfo {
  */
 
 struct gfar_priv_grp {
-	spinlock_t grplock __attribute__ ((aligned (SMP_CACHE_BYTES)));
-	struct	napi_struct napi;
-	struct gfar_private *priv;
+	spinlock_t grplock __aligned(SMP_CACHE_BYTES);
+	struct	napi_struct napi_rx;
+	struct	napi_struct napi_tx;
 	struct gfar __iomem *regs;
-	unsigned int rstat;
-	unsigned long num_rx_queues;
-	unsigned long rx_bit_map;
-	/* cacheline 3 */
+	struct gfar_priv_tx_q *tx_queue;
+	struct gfar_priv_rx_q *rx_queue;
 	unsigned int tstat;
+	unsigned int rstat;
+
+	struct gfar_private *priv;
 	unsigned long num_tx_queues;
 	unsigned long tx_bit_map;
+	unsigned long num_rx_queues;
+	unsigned long rx_bit_map;
 
 	struct gfar_irqinfo *irqinfo[GFAR_NUM_IRQS];
 };
@@ -1053,8 +1077,6 @@ enum gfar_dev_state {
  * the buffer descriptor determines the actual condition.
  */
 struct gfar_private {
-	unsigned int num_rx_queues;
-
 	struct device *dev;
 	struct net_device *ndev;
 	enum gfar_errata errata;
@@ -1062,6 +1084,7 @@ struct gfar_private {
 
 	u16 uses_rxfcb;
 	u16 padding;
+	u32 device_flags;
 
 	/* HW time stamping enabled flag */
 	int hwts_rx_en;
@@ -1072,10 +1095,11 @@ struct gfar_private {
 	struct gfar_priv_grp gfargrp[MAXGROUPS];
 
 	unsigned long state;
-	u32 device_flags;
 
-	unsigned int mode;
+	unsigned short mode;
+	unsigned short poll_mode;
 	unsigned int num_tx_queues;
+	unsigned int num_rx_queues;
 	unsigned int num_grps;
 
 	/* Network Statistics */