Revert "mvebu: remove linux 4.4 support"

This reverts commit 51397d7d95d9f5e210a5557f65de1fa21e6f5921.
There are some unresolved random crashes on WRT1900AC v1 that still need
to be sorted out

Signed-off-by: Felix Fietkau <nbd@nbd.name>

1 files changed, 124 insertions, 0 deletions

diff --git a/target/linux/mvebu/patches-4.4/035-net-mvneta-Configure-XPS-support.patch b/target/linux/mvebu/patches-4.4/035-net-mvneta-Configure-XPS-support.patch
new file mode 100644
index 0000000000..5b35b6442b
--- /dev/null
+++ b/target/linux/mvebu/patches-4.4/035-net-mvneta-Configure-XPS-support.patch
@@ -0,0 +1,124 @@
+From: Gregory CLEMENT <gregory.clement@free-electrons.com>
+Date: Wed, 9 Dec 2015 18:23:51 +0100
+Subject: [PATCH] net: mvneta: Configure XPS support
+
+With this patch each CPU is associated with its own set of TX queues.
+
+It also setup the XPS with an initial configuration which set the
+affinity matching the hardware configuration.
+
+Suggested-by: Arnd Bergmann <arnd@arndb.de>
+Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/drivers/net/ethernet/marvell/mvneta.c
++++ b/drivers/net/ethernet/marvell/mvneta.c
+@@ -111,6 +111,7 @@
+ #define      MVNETA_CPU_RXQ_ACCESS_ALL_MASK      0x000000ff
+ #define      MVNETA_CPU_TXQ_ACCESS_ALL_MASK      0x0000ff00
+ #define      MVNETA_CPU_RXQ_ACCESS(rxq)		 BIT(rxq)
++#define      MVNETA_CPU_TXQ_ACCESS(txq)		 BIT(txq + 8)
+ #define MVNETA_RXQ_TIME_COAL_REG(q)              (0x2580 + ((q) << 2))
+ 
+ /* Exception Interrupt Port/Queue Cause register
+@@ -514,6 +515,9 @@ struct mvneta_tx_queue {
+ 
+ 	/* DMA address of TSO headers */
+ 	dma_addr_t tso_hdrs_phys;
++
++	/* Affinity mask for CPUs*/
++	cpumask_t affinity_mask;
+ };
+ 
+ struct mvneta_rx_queue {
+@@ -1062,20 +1066,30 @@ static void mvneta_defaults_set(struct m
+ 	/* Enable MBUS Retry bit16 */
+ 	mvreg_write(pp, MVNETA_MBUS_RETRY, 0x20);
+ 
+-	/* Set CPU queue access map. CPUs are assigned to the RX
+-	 * queues modulo their number and all the TX queues are
+-	 * assigned to the CPU associated to the default RX queue.
++	/* Set CPU queue access map. CPUs are assigned to the RX and
++	 * TX queues modulo their number. If there is only one TX
++	 * queue then it is assigned to the CPU associated to the
++	 * default RX queue.
+ 	 */
+ 	for_each_present_cpu(cpu) {
+ 		int rxq_map = 0, txq_map = 0;
+-		int rxq;
++		int rxq, txq;
+ 
+ 		for (rxq = 0; rxq < rxq_number; rxq++)
+ 			if ((rxq % max_cpu) == cpu)
+ 				rxq_map |= MVNETA_CPU_RXQ_ACCESS(rxq);
+ 
+-		if (cpu == pp->rxq_def)
+-			txq_map = MVNETA_CPU_TXQ_ACCESS_ALL_MASK;
++		for (txq = 0; txq < txq_number; txq++)
++			if ((txq % max_cpu) == cpu)
++				txq_map |= MVNETA_CPU_TXQ_ACCESS(txq);
++
++		/* With only one TX queue we configure a special case
++		 * which will allow to get all the irq on a single
++		 * CPU
++		 */
++		if (txq_number == 1)
++			txq_map = (cpu == pp->rxq_def) ?
++				MVNETA_CPU_TXQ_ACCESS(1) : 0;
+ 
+ 		mvreg_write(pp, MVNETA_CPU_MAP(cpu), rxq_map | txq_map);
+ 	}
+@@ -2362,6 +2376,8 @@ static void mvneta_rxq_deinit(struct mvn
+ static int mvneta_txq_init(struct mvneta_port *pp,
+ 			   struct mvneta_tx_queue *txq)
+ {
++	int cpu;
++
+ 	txq->size = pp->tx_ring_size;
+ 
+ 	/* A queue must always have room for at least one skb.
+@@ -2414,6 +2430,14 @@ static int mvneta_txq_init(struct mvneta
+ 	}
+ 	mvneta_tx_done_pkts_coal_set(pp, txq, txq->done_pkts_coal);
+ 
++	/* Setup XPS mapping */
++	if (txq_number > 1)
++		cpu = txq->id % num_present_cpus();
++	else
++		cpu = pp->rxq_def % num_present_cpus();
++	cpumask_set_cpu(cpu, &txq->affinity_mask);
++	netif_set_xps_queue(pp->dev, &txq->affinity_mask, txq->id);
++
+ 	return 0;
+ }
+ 
+@@ -2836,13 +2860,23 @@ static void mvneta_percpu_elect(struct m
+ 			if ((rxq % max_cpu) == cpu)
+ 				rxq_map |= MVNETA_CPU_RXQ_ACCESS(rxq);
+ 
+-		if (i == online_cpu_idx) {
+-			/* Map the default receive queue and transmit
+-			 * queue to the elected CPU
++		if (i == online_cpu_idx)
++			/* Map the default receive queue queue to the
++			 * elected CPU
+ 			 */
+ 			rxq_map |= MVNETA_CPU_RXQ_ACCESS(pp->rxq_def);
+-			txq_map = MVNETA_CPU_TXQ_ACCESS_ALL_MASK;
+-		}
++
++		/* We update the TX queue map only if we have one
++		 * queue. In this case we associate the TX queue to
++		 * the CPU bound to the default RX queue
++		 */
++		if (txq_number == 1)
++			txq_map = (i == online_cpu_idx) ?
++				MVNETA_CPU_TXQ_ACCESS(1) : 0;
++		else
++			txq_map = mvreg_read(pp, MVNETA_CPU_MAP(cpu)) &
++				MVNETA_CPU_TXQ_ACCESS_ALL_MASK;
++
+ 		mvreg_write(pp, MVNETA_CPU_MAP(cpu), rxq_map | txq_map);
+ 
+ 		/* Update the interrupt mask on each CPU according the