brcm47xx: bgmac: implement unaligned addressing for DMA rings that support it

This is important patch for new devices that support unaligned
addressing. That devices suffer from the backward-compatibility bug in
DMA engine. In theory we should be able to use old mechanism, but in
practice DMA address seems to be randomly copied into status register
when hardware reaches end of a ring. This breaks reading slot number
from status register and we can't use DMA anymore.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>


git-svn-id: svn://svn.openwrt.org/openwrt/trunk@38004 3c298f89-4303-0410-b956-a3cf2f4a3e73

2 files changed, 146 insertions, 6 deletions

diff --git a/target/linux/brcm47xx/patches-3.10/712-bgmac_implement_unaligned_addressing.patch b/target/linux/brcm47xx/patches-3.10/712-bgmac_implement_unaligned_addressing.patch
new file mode 100644
index 0000000000..939ae114bb
--- /dev/null
+++ b/target/linux/brcm47xx/patches-3.10/712-bgmac_implement_unaligned_addressing.patch
@@ -0,0 +1,140 @@
+bgmac: implement unaligned addressing for DMA rings that support it
+
+This is important patch for new devices that support unaligned
+addressing. That devices suffer from the backward-compatibility bug in
+DMA engine. In theory we should be able to use old mechanism, but in
+practice DMA address seems to be randomly copied into status register
+when hardware reaches end of a ring. This breaks reading slot number
+from status register and we can't use DMA anymore.
+
+Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
+
+--- a/drivers/net/ethernet/broadcom/bgmac.c
++++ b/drivers/net/ethernet/broadcom/bgmac.c
+@@ -157,6 +157,7 @@ static netdev_tx_t bgmac_dma_tx_add(stru
+ 	if (++ring->end >= BGMAC_TX_RING_SLOTS)
+ 		ring->end = 0;
+ 	bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_TX_INDEX,
++		    ring->index_base +
+ 		    ring->end * sizeof(struct bgmac_dma_desc));
+ 
+ 	/* Always keep one slot free to allow detecting bugged calls. */
+@@ -181,6 +182,8 @@ static void bgmac_dma_tx_free(struct bgm
+ 	/* The last slot that hardware didn't consume yet */
+ 	empty_slot = bgmac_read(bgmac, ring->mmio_base + BGMAC_DMA_TX_STATUS);
+ 	empty_slot &= BGMAC_DMA_TX_STATDPTR;
++	empty_slot -= ring->index_base;
++	empty_slot &= BGMAC_DMA_TX_STATDPTR;
+ 	empty_slot /= sizeof(struct bgmac_dma_desc);
+ 
+ 	while (ring->start != empty_slot) {
+@@ -274,6 +277,8 @@ static int bgmac_dma_rx_read(struct bgma
+ 
+ 	end_slot = bgmac_read(bgmac, ring->mmio_base + BGMAC_DMA_RX_STATUS);
+ 	end_slot &= BGMAC_DMA_RX_STATDPTR;
++	end_slot -= ring->index_base;
++	end_slot &= BGMAC_DMA_RX_STATDPTR;
+ 	end_slot /= sizeof(struct bgmac_dma_desc);
+ 
+ 	ring->end = end_slot;
+@@ -418,9 +423,6 @@ static int bgmac_dma_alloc(struct bgmac
+ 		ring = &bgmac->tx_ring[i];
+ 		ring->num_slots = BGMAC_TX_RING_SLOTS;
+ 		ring->mmio_base = ring_base[i];
+-		if (bgmac_dma_unaligned(bgmac, ring, BGMAC_DMA_RING_TX))
+-			bgmac_warn(bgmac, "TX on ring 0x%X supports unaligned addressing but this feature is not implemented\n",
+-				   ring->mmio_base);
+ 
+ 		/* Alloc ring of descriptors */
+ 		size = ring->num_slots * sizeof(struct bgmac_dma_desc);
+@@ -435,6 +437,13 @@ static int bgmac_dma_alloc(struct bgmac
+ 		if (ring->dma_base & 0xC0000000)
+ 			bgmac_warn(bgmac, "DMA address using 0xC0000000 bit(s), it may need translation trick\n");
+ 
++		ring->unaligned = bgmac_dma_unaligned(bgmac, ring,
++						      BGMAC_DMA_RING_TX);
++		if (ring->unaligned)
++			ring->index_base = lower_32_bits(ring->dma_base);
++		else
++			ring->index_base = 0;
++
+ 		/* No need to alloc TX slots yet */
+ 	}
+ 
+@@ -444,9 +453,6 @@ static int bgmac_dma_alloc(struct bgmac
+ 		ring = &bgmac->rx_ring[i];
+ 		ring->num_slots = BGMAC_RX_RING_SLOTS;
+ 		ring->mmio_base = ring_base[i];
+-		if (bgmac_dma_unaligned(bgmac, ring, BGMAC_DMA_RING_RX))
+-			bgmac_warn(bgmac, "RX on ring 0x%X supports unaligned addressing but this feature is not implemented\n",
+-				   ring->mmio_base);
+ 
+ 		/* Alloc ring of descriptors */
+ 		size = ring->num_slots * sizeof(struct bgmac_dma_desc);
+@@ -462,6 +468,13 @@ static int bgmac_dma_alloc(struct bgmac
+ 		if (ring->dma_base & 0xC0000000)
+ 			bgmac_warn(bgmac, "DMA address using 0xC0000000 bit(s), it may need translation trick\n");
+ 
++		ring->unaligned = bgmac_dma_unaligned(bgmac, ring,
++						      BGMAC_DMA_RING_RX);
++		if (ring->unaligned)
++			ring->index_base = lower_32_bits(ring->dma_base);
++		else
++			ring->index_base = 0;
++
+ 		/* Alloc RX slots */
+ 		for (j = 0; j < ring->num_slots; j++) {
+ 			err = bgmac_dma_rx_skb_for_slot(bgmac, &ring->slots[j]);
+@@ -489,12 +502,14 @@ static void bgmac_dma_init(struct bgmac
+ 	for (i = 0; i < BGMAC_MAX_TX_RINGS; i++) {
+ 		ring = &bgmac->tx_ring[i];
+ 
+-		/* We don't implement unaligned addressing, so enable first */
+-		bgmac_dma_tx_enable(bgmac, ring);
++		if (!ring->unaligned)
++			bgmac_dma_tx_enable(bgmac, ring);
+ 		bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_TX_RINGLO,
+ 			    lower_32_bits(ring->dma_base));
+ 		bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_TX_RINGHI,
+ 			    upper_32_bits(ring->dma_base));
++		if (ring->unaligned)
++			bgmac_dma_tx_enable(bgmac, ring);
+ 
+ 		ring->start = 0;
+ 		ring->end = 0;	/* Points the slot that should *not* be read */
+@@ -505,12 +520,14 @@ static void bgmac_dma_init(struct bgmac
+ 
+ 		ring = &bgmac->rx_ring[i];
+ 
+-		/* We don't implement unaligned addressing, so enable first */
+-		bgmac_dma_rx_enable(bgmac, ring);
++		if (!ring->unaligned)
++			bgmac_dma_rx_enable(bgmac, ring);
+ 		bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_RX_RINGLO,
+ 			    lower_32_bits(ring->dma_base));
+ 		bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_RX_RINGHI,
+ 			    upper_32_bits(ring->dma_base));
++		if (ring->unaligned)
++			bgmac_dma_rx_enable(bgmac, ring);
+ 
+ 		for (j = 0, dma_desc = ring->cpu_base; j < ring->num_slots;
+ 		     j++, dma_desc++) {
+@@ -531,6 +548,7 @@ static void bgmac_dma_init(struct bgmac
+ 		}
+ 
+ 		bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_RX_INDEX,
++			    ring->index_base +
+ 			    ring->num_slots * sizeof(struct bgmac_dma_desc));
+ 
+ 		ring->start = 0;
+--- a/drivers/net/ethernet/broadcom/bgmac.h
++++ b/drivers/net/ethernet/broadcom/bgmac.h
+@@ -384,6 +384,8 @@ struct bgmac_dma_ring {
+ 	u16 mmio_base;
+ 	struct bgmac_dma_desc *cpu_base;
+ 	dma_addr_t dma_base;
++	u32 index_base; /* Used for unaligned rings only, otherwise 0 */
++	bool unaligned;
+ 
+ 	struct bgmac_slot_info slots[BGMAC_RX_RING_SLOTS];
+ };
diff --git a/target/linux/brcm47xx/patches-3.10/770-bgmac-phylib.patch b/target/linux/brcm47xx/patches-3.10/770-bgmac-phylib.patch
index 6041d2a77a..33308319db 100644
--- a/target/linux/brcm47xx/patches-3.10/770-bgmac-phylib.patch
+++ b/target/linux/brcm47xx/patches-3.10/770-bgmac-phylib.patch
@@ -10,7 +10,7 @@
  	  They can be found on BCM47xx SoCs and provide gigabit ethernet.
 --- a/drivers/net/ethernet/broadcom/bgmac.c
 +++ b/drivers/net/ethernet/broadcom/bgmac.c
-@@ -1201,27 +1201,14 @@ static int bgmac_set_mac_address(struct
+@@ -1219,27 +1219,14 @@ static int bgmac_set_mac_address(struct
  static int bgmac_ioctl(struct net_device *net_dev, struct ifreq *ifr, int cmd)
  {
  	struct bgmac *bgmac = netdev_priv(net_dev);
@@ -45,7 +45,7 @@
  }
  
  static const struct net_device_ops bgmac_netdev_ops = {
-@@ -1243,61 +1230,18 @@ static int bgmac_get_settings(struct net
+@@ -1261,61 +1248,18 @@ static int bgmac_get_settings(struct net
  {
  	struct bgmac *bgmac = netdev_priv(net_dev);
  
@@ -111,7 +111,7 @@
  
  static void bgmac_get_drvinfo(struct net_device *net_dev,
  			      struct ethtool_drvinfo *info)
-@@ -1308,6 +1252,7 @@ static void bgmac_get_drvinfo(struct net
+@@ -1326,6 +1270,7 @@ static void bgmac_get_drvinfo(struct net
  
  static const struct ethtool_ops bgmac_ethtool_ops = {
  	.get_settings		= bgmac_get_settings,
@@ -119,7 +119,7 @@
  	.get_drvinfo		= bgmac_get_drvinfo,
  };
  
-@@ -1326,10 +1271,42 @@ static int bgmac_mii_write(struct mii_bu
+@@ -1344,10 +1289,42 @@ static int bgmac_mii_write(struct mii_bu
  	return bgmac_phy_write(bus->priv, mii_id, regnum, value);
  }
  
@@ -162,7 +162,7 @@
  
  	mii_bus = mdiobus_alloc();
  	if (!mii_bus)
-@@ -1360,7 +1337,29 @@ static int bgmac_mii_register(struct bgm
+@@ -1378,7 +1355,29 @@ static int bgmac_mii_register(struct bgm
  
  	bgmac->mii_bus = mii_bus;
  
@@ -195,7 +195,7 @@
  	kfree(mii_bus->irq);
 --- a/drivers/net/ethernet/broadcom/bgmac.h
 +++ b/drivers/net/ethernet/broadcom/bgmac.h
-@@ -399,7 +399,10 @@ struct bgmac {
+@@ -401,7 +401,10 @@ struct bgmac {
  	struct bcma_device *cmn; /* Reference to CMN core for BCM4706 */
  	struct net_device *net_dev;
  	struct napi_struct napi;