kernel: add bgmac fixes for various issues

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

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@45388 3c298f89-4303-0410-b956-a3cf2f4a3e73

4 files changed, 330 insertions, 0 deletions

diff --git a/target/linux/generic/patches-3.18/077-04-bgmac-simplify-tx-ring-index-handling.patch b/target/linux/generic/patches-3.18/077-04-bgmac-simplify-tx-ring-index-handling.patch
new file mode 100644
index 0000000000..cf62a50a2f
--- /dev/null
+++ b/target/linux/generic/patches-3.18/077-04-bgmac-simplify-tx-ring-index-handling.patch
@@ -0,0 +1,123 @@
+From: Felix Fietkau <nbd@openwrt.org>
+Date: Sun, 12 Apr 2015 09:58:56 +0200
+Subject: [PATCH] bgmac: simplify tx ring index handling
+
+Keep incrementing ring->start and ring->end instead of pointing it to
+the actual ring slot entry. This simplifies the calculation of the
+number of free slots.
+
+Signed-off-by: Felix Fietkau <nbd@openwrt.org>
+---
+
+--- a/drivers/net/ethernet/broadcom/bgmac.c
++++ b/drivers/net/ethernet/broadcom/bgmac.c
+@@ -142,11 +142,10 @@ static netdev_tx_t bgmac_dma_tx_add(stru
+ {
+ 	struct device *dma_dev = bgmac->core->dma_dev;
+ 	struct net_device *net_dev = bgmac->net_dev;
+-	struct bgmac_slot_info *slot = &ring->slots[ring->end];
+-	int free_slots;
++	int index = ring->end % BGMAC_TX_RING_SLOTS;
++	struct bgmac_slot_info *slot = &ring->slots[index];
+ 	int nr_frags;
+ 	u32 flags;
+-	int index = ring->end;
+ 	int i;
+ 
+ 	if (skb->len > BGMAC_DESC_CTL1_LEN) {
+@@ -158,13 +157,7 @@ static netdev_tx_t bgmac_dma_tx_add(stru
+ 		skb_checksum_help(skb);
+ 
+ 	nr_frags = skb_shinfo(skb)->nr_frags;
+-
+-	if (ring->start <= ring->end)
+-		free_slots = ring->start - ring->end + BGMAC_TX_RING_SLOTS;
+-	else
+-		free_slots = ring->start - ring->end;
+-
+-	if (free_slots <= nr_frags + 1) {
++	if (ring->end - ring->start + nr_frags + 1 >= BGMAC_TX_RING_SLOTS) {
+ 		bgmac_err(bgmac, "TX ring is full, queue should be stopped!\n");
+ 		netif_stop_queue(net_dev);
+ 		return NETDEV_TX_BUSY;
+@@ -200,7 +193,7 @@ static netdev_tx_t bgmac_dma_tx_add(stru
+ 	}
+ 
+ 	slot->skb = skb;
+-
++	ring->end += nr_frags + 1;
+ 	netdev_sent_queue(net_dev, skb->len);
+ 
+ 	wmb();
+@@ -208,13 +201,12 @@ static netdev_tx_t bgmac_dma_tx_add(stru
+ 	/* Increase ring->end to point empty slot. We tell hardware the first
+ 	 * slot it should *not* read.
+ 	 */
+-	ring->end = (index + 1) % BGMAC_TX_RING_SLOTS;
+ 	bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_TX_INDEX,
+ 		    ring->index_base +
+-		    ring->end * sizeof(struct bgmac_dma_desc));
++		    (ring->end % BGMAC_TX_RING_SLOTS) *
++		    sizeof(struct bgmac_dma_desc));
+ 
+-	free_slots -= nr_frags + 1;
+-	if (free_slots < 8)
++	if (ring->end - ring->start >= BGMAC_TX_RING_SLOTS - 8)
+ 		netif_stop_queue(net_dev);
+ 
+ 	return NETDEV_TX_OK;
+@@ -256,17 +248,17 @@ static void bgmac_dma_tx_free(struct bgm
+ 	empty_slot &= BGMAC_DMA_TX_STATDPTR;
+ 	empty_slot /= sizeof(struct bgmac_dma_desc);
+ 
+-	while (ring->start != empty_slot) {
+-		struct bgmac_slot_info *slot = &ring->slots[ring->start];
+-		u32 ctl1 = le32_to_cpu(ring->cpu_base[ring->start].ctl1);
+-		int len = ctl1 & BGMAC_DESC_CTL1_LEN;
++	while (ring->start != ring->end) {
++		int slot_idx = ring->start % BGMAC_TX_RING_SLOTS;
++		struct bgmac_slot_info *slot = &ring->slots[slot_idx];
++		u32 ctl1;
++		int len;
+ 
+-		if (!slot->dma_addr) {
+-			bgmac_err(bgmac, "Hardware reported transmission for empty TX ring slot %d! End of ring: %d\n",
+-				  ring->start, ring->end);
+-			goto next;
+-		}
++		if (slot_idx == empty_slot)
++			break;
+ 
++		ctl1 = le32_to_cpu(ring->cpu_base[slot_idx].ctl1);
++		len = ctl1 & BGMAC_DESC_CTL1_LEN;
+ 		if (ctl1 & BGMAC_DESC_CTL0_SOF)
+ 			/* Unmap no longer used buffer */
+ 			dma_unmap_single(dma_dev, slot->dma_addr, len,
+@@ -284,10 +276,8 @@ static void bgmac_dma_tx_free(struct bgm
+ 			slot->skb = NULL;
+ 		}
+ 
+-next:
+ 		slot->dma_addr = 0;
+-		if (++ring->start >= BGMAC_TX_RING_SLOTS)
+-			ring->start = 0;
++		ring->start++;
+ 		freed = true;
+ 	}
+ 
+--- a/drivers/net/ethernet/broadcom/bgmac.h
++++ b/drivers/net/ethernet/broadcom/bgmac.h
+@@ -414,10 +414,10 @@ enum bgmac_dma_ring_type {
+  * empty.
+  */
+ struct bgmac_dma_ring {
+-	u16 num_slots;
+-	u16 start;
+-	u16 end;
++	u32 start;
++	u32 end;
+ 
++	u16 num_slots;
+ 	u16 mmio_base;
+ 	struct bgmac_dma_desc *cpu_base;
+ 	dma_addr_t dma_base;
diff --git a/target/linux/generic/patches-3.18/077-05-bgmac-leave-interrupts-disabled-as-long-as-there-is-.patch b/target/linux/generic/patches-3.18/077-05-bgmac-leave-interrupts-disabled-as-long-as-there-is-.patch
new file mode 100644
index 0000000000..79746540c9
--- /dev/null
+++ b/target/linux/generic/patches-3.18/077-05-bgmac-leave-interrupts-disabled-as-long-as-there-is-.patch
@@ -0,0 +1,87 @@
+From: Felix Fietkau <nbd@openwrt.org>
+Date: Sun, 12 Apr 2015 10:08:04 +0200
+Subject: [PATCH] bgmac: leave interrupts disabled as long as there is work
+ to do
+
+Always poll rx and tx during NAPI poll instead of relying on the status
+of the first interrupt. This prevents bgmac_poll from leaving unfinished
+work around until the next IRQ.
+In my tests this makes bridging/routing throughput under heavy load more
+stable and ensures that no new IRQs arrive as long as bgmac_poll uses up
+the entire budget.
+
+Signed-off-by: Felix Fietkau <nbd@openwrt.org>
+---
+
+--- a/drivers/net/ethernet/broadcom/bgmac.c
++++ b/drivers/net/ethernet/broadcom/bgmac.c
+@@ -1105,8 +1105,6 @@ static void bgmac_chip_reset(struct bgma
+ 	bgmac_phy_init(bgmac);
+ 
+ 	netdev_reset_queue(bgmac->net_dev);
+-
+-	bgmac->int_status = 0;
+ }
+ 
+ static void bgmac_chip_intrs_on(struct bgmac *bgmac)
+@@ -1221,14 +1219,13 @@ static irqreturn_t bgmac_interrupt(int i
+ 	if (!int_status)
+ 		return IRQ_NONE;
+ 
+-	/* Ack */
+-	bgmac_write(bgmac, BGMAC_INT_STATUS, int_status);
++	int_status &= ~(BGMAC_IS_TX0 | BGMAC_IS_RX);
++	if (int_status)
++		bgmac_err(bgmac, "Unknown IRQs: 0x%08X\n", int_status);
+ 
+ 	/* Disable new interrupts until handling existing ones */
+ 	bgmac_chip_intrs_off(bgmac);
+ 
+-	bgmac->int_status = int_status;
+-
+ 	napi_schedule(&bgmac->napi);
+ 
+ 	return IRQ_HANDLED;
+@@ -1237,25 +1234,17 @@ static irqreturn_t bgmac_interrupt(int i
+ static int bgmac_poll(struct napi_struct *napi, int weight)
+ {
+ 	struct bgmac *bgmac = container_of(napi, struct bgmac, napi);
+-	struct bgmac_dma_ring *ring;
+ 	int handled = 0;
+ 
+-	if (bgmac->int_status & BGMAC_IS_TX0) {
+-		ring = &bgmac->tx_ring[0];
+-		bgmac_dma_tx_free(bgmac, ring);
+-		bgmac->int_status &= ~BGMAC_IS_TX0;
+-	}
++	/* Ack */
++	bgmac_write(bgmac, BGMAC_INT_STATUS, ~0);
+ 
+-	if (bgmac->int_status & BGMAC_IS_RX) {
+-		ring = &bgmac->rx_ring[0];
+-		handled += bgmac_dma_rx_read(bgmac, ring, weight);
+-		bgmac->int_status &= ~BGMAC_IS_RX;
+-	}
++	bgmac_dma_tx_free(bgmac, &bgmac->tx_ring[0]);
++	handled += bgmac_dma_rx_read(bgmac, &bgmac->rx_ring[0], weight);
+ 
+-	if (bgmac->int_status) {
+-		bgmac_err(bgmac, "Unknown IRQs: 0x%08X\n", bgmac->int_status);
+-		bgmac->int_status = 0;
+-	}
++	/* poll again if more events arrived in the mean time */
++	if (bgmac_read(bgmac, BGMAC_INT_STATUS) & (BGMAC_IS_TX0 | BGMAC_IS_RX))
++		return handled;
+ 
+ 	if (handled < weight) {
+ 		napi_complete(napi);
+--- a/drivers/net/ethernet/broadcom/bgmac.h
++++ b/drivers/net/ethernet/broadcom/bgmac.h
+@@ -452,7 +452,6 @@ struct bgmac {
+ 
+ 	/* Int */
+ 	u32 int_mask;
+-	u32 int_status;
+ 
+ 	/* Current MAC state */
+ 	int mac_speed;
diff --git a/target/linux/generic/patches-3.18/077-06-bgmac-set-received-skb-headroom-to-NET_SKB_PAD.patch b/target/linux/generic/patches-3.18/077-06-bgmac-set-received-skb-headroom-to-NET_SKB_PAD.patch
new file mode 100644
index 0000000000..e7fde163fd
--- /dev/null
+++ b/target/linux/generic/patches-3.18/077-06-bgmac-set-received-skb-headroom-to-NET_SKB_PAD.patch
@@ -0,0 +1,66 @@
+From: Felix Fietkau <nbd@openwrt.org>
+Date: Sun, 12 Apr 2015 10:13:28 +0200
+Subject: [PATCH] bgmac: set received skb headroom to NET_SKB_PAD
+
+A packet buffer offset of 30 bytes is inefficient, because the first 2
+bytes end up in a different cacheline.
+
+Signed-off-by: Felix Fietkau <nbd@openwrt.org>
+---
+
+--- a/drivers/net/ethernet/broadcom/bgmac.c
++++ b/drivers/net/ethernet/broadcom/bgmac.c
+@@ -342,13 +342,13 @@ static int bgmac_dma_rx_skb_for_slot(str
+ 		return -ENOMEM;
+ 
+ 	/* Poison - if everything goes fine, hardware will overwrite it */
+-	rx = buf;
++	rx = buf + BGMAC_RX_BUF_OFFSET;
+ 	rx->len = cpu_to_le16(0xdead);
+ 	rx->flags = cpu_to_le16(0xbeef);
+ 
+ 	/* Map skb for the DMA */
+-	dma_addr = dma_map_single(dma_dev, buf, BGMAC_RX_BUF_SIZE,
+-				  DMA_FROM_DEVICE);
++	dma_addr = dma_map_single(dma_dev, buf + BGMAC_RX_BUF_OFFSET,
++				  BGMAC_RX_BUF_SIZE, DMA_FROM_DEVICE);
+ 	if (dma_mapping_error(dma_dev, dma_addr)) {
+ 		bgmac_err(bgmac, "DMA mapping error\n");
+ 		put_page(virt_to_head_page(buf));
+@@ -399,7 +399,7 @@ static int bgmac_dma_rx_read(struct bgma
+ 	while (ring->start != ring->end) {
+ 		struct device *dma_dev = bgmac->core->dma_dev;
+ 		struct bgmac_slot_info *slot = &ring->slots[ring->start];
+-		struct bgmac_rx_header *rx = slot->buf;
++		struct bgmac_rx_header *rx = slot->buf + BGMAC_RX_BUF_OFFSET;
+ 		struct sk_buff *skb;
+ 		void *buf = slot->buf;
+ 		u16 len, flags;
+@@ -450,8 +450,10 @@ static int bgmac_dma_rx_read(struct bgma
+ 					 BGMAC_RX_BUF_SIZE, DMA_FROM_DEVICE);
+ 
+ 			skb = build_skb(buf, BGMAC_RX_ALLOC_SIZE);
+-			skb_put(skb, BGMAC_RX_FRAME_OFFSET + len);
+-			skb_pull(skb, BGMAC_RX_FRAME_OFFSET);
++			skb_put(skb, BGMAC_RX_FRAME_OFFSET +
++				BGMAC_RX_BUF_OFFSET + len);
++			skb_pull(skb, BGMAC_RX_FRAME_OFFSET +
++				 BGMAC_RX_BUF_OFFSET);
+ 
+ 			skb_checksum_none_assert(skb);
+ 			skb->protocol = eth_type_trans(skb, bgmac->net_dev);
+--- a/drivers/net/ethernet/broadcom/bgmac.h
++++ b/drivers/net/ethernet/broadcom/bgmac.h
+@@ -360,9 +360,11 @@
+ 
+ #define BGMAC_RX_HEADER_LEN			28		/* Last 24 bytes are unused. Well... */
+ #define BGMAC_RX_FRAME_OFFSET			30		/* There are 2 unused bytes between header and real data */
++#define BGMAC_RX_BUF_OFFSET			(NET_SKB_PAD + NET_IP_ALIGN - \
++						 BGMAC_RX_FRAME_OFFSET)
+ #define BGMAC_RX_MAX_FRAME_SIZE			1536		/* Copied from b44/tg3 */
+ #define BGMAC_RX_BUF_SIZE			(BGMAC_RX_FRAME_OFFSET + BGMAC_RX_MAX_FRAME_SIZE)
+-#define BGMAC_RX_ALLOC_SIZE			(SKB_DATA_ALIGN(BGMAC_RX_BUF_SIZE) + \
++#define BGMAC_RX_ALLOC_SIZE			(SKB_DATA_ALIGN(BGMAC_RX_BUF_SIZE + BGMAC_RX_BUF_OFFSET) + \
+ 						 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
+ 
+ #define BGMAC_BFL_ENETROBO			0x0010		/* has ephy roboswitch spi */
diff --git a/target/linux/generic/patches-3.18/077-07-bgmac-fix-DMA-rx-corruption.patch b/target/linux/generic/patches-3.18/077-07-bgmac-fix-DMA-rx-corruption.patch
new file mode 100644
index 0000000000..55e80332bd
--- /dev/null
+++ b/target/linux/generic/patches-3.18/077-07-bgmac-fix-DMA-rx-corruption.patch
@@ -0,0 +1,54 @@
+From: Felix Fietkau <nbd@openwrt.org>
+Date: Sun, 12 Apr 2015 11:59:47 +0200
+Subject: [PATCH] bgmac: fix DMA rx corruption
+
+The driver needs to inform the hardware about the first invalid (not yet
+filled) rx slot, by writing its DMA descriptor pointer offset to the
+BGMAC_DMA_RX_INDEX register.
+
+This register was set to a value exceeding the rx ring size, effectively
+allowing the hardware constant access to the full ring, regardless of
+which slots are initialized.
+
+Fix this by updating the register in bgmac_dma_rx_setup_desc.
+
+Signed-off-by: Felix Fietkau <nbd@openwrt.org>
+---
+
+--- a/drivers/net/ethernet/broadcom/bgmac.c
++++ b/drivers/net/ethernet/broadcom/bgmac.c
+@@ -380,6 +380,12 @@ static void bgmac_dma_rx_setup_desc(stru
+ 	dma_desc->addr_high = cpu_to_le32(upper_32_bits(ring->slots[desc_idx].dma_addr));
+ 	dma_desc->ctl0 = cpu_to_le32(ctl0);
+ 	dma_desc->ctl1 = cpu_to_le32(ctl1);
++
++	desc_idx = (desc_idx + 1) % BGMAC_RX_RING_SLOTS;
++
++	bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_RX_INDEX,
++			ring->index_base +
++			desc_idx * sizeof(struct bgmac_dma_desc));
+ }
+ 
+ static int bgmac_dma_rx_read(struct bgmac *bgmac, struct bgmac_dma_ring *ring,
+@@ -394,9 +400,7 @@ static int bgmac_dma_rx_read(struct bgma
+ 	end_slot &= BGMAC_DMA_RX_STATDPTR;
+ 	end_slot /= sizeof(struct bgmac_dma_desc);
+ 
+-	ring->end = end_slot;
+-
+-	while (ring->start != ring->end) {
++	while (ring->start != end_slot) {
+ 		struct device *dma_dev = bgmac->core->dma_dev;
+ 		struct bgmac_slot_info *slot = &ring->slots[ring->start];
+ 		struct bgmac_rx_header *rx = slot->buf + BGMAC_RX_BUF_OFFSET;
+@@ -693,10 +697,6 @@ static void bgmac_dma_init(struct bgmac 
+ 		for (j = 0; j < ring->num_slots; j++)
+ 			bgmac_dma_rx_setup_desc(bgmac, ring, j);
+ 
+-		bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_RX_INDEX,
+-			    ring->index_base +
+-			    ring->num_slots * sizeof(struct bgmac_dma_desc));
+-
+ 		ring->start = 0;
+ 		ring->end = 0;
+ 	}