pasemi_mac: add support for setting MTU

Currently keeping it at 1500 bytes or below since jumbo frames need
special checksum offload on TX.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 158 insertions, 72 deletions

diff --git a/drivers/net/pasemi_mac.c b/drivers/net/pasemi_mac.c
index 59dea3f829fc..059c6b04dc8f 100644
--- a/drivers/net/pasemi_mac.c
+++ b/drivers/net/pasemi_mac.c
@@ -62,6 +62,10 @@
 
 #define LRO_MAX_AGGR 64
 
+#define PE_MIN_MTU      64
+#define PE_MAX_MTU      1500
+#define PE_DEF_MTU      ETH_DATA_LEN
+
 #define DEFAULT_MSG_ENABLE        \
         (NETIF_MSG_DRV          | \
          NETIF_MSG_PROBE        | \
@@ -82,8 +86,6 @@
                                  & ((ring)->size - 1))
 #define RING_AVAIL(ring)        ((ring->size) - RING_USED(ring))
 
-#define BUF_SIZE 1646 /* 1500 MTU + ETH_HLEN + VLAN_HLEN + 2 64B cachelines */
-
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR ("Olof Johansson <olof@lixom.net>");
 MODULE_DESCRIPTION("PA Semi PWRficient Ethernet driver");
@@ -175,6 +177,24 @@ static int mac_to_intf(struct pasemi_mac *mac)
         return -1;
 }
 
+static void pasemi_mac_intf_disable(struct pasemi_mac *mac)
+{
+        unsigned int flags;
+
+        flags = read_mac_reg(mac, PAS_MAC_CFG_PCFG);
+        flags &= ~PAS_MAC_CFG_PCFG_PE;
+        write_mac_reg(mac, PAS_MAC_CFG_PCFG, flags);
+}
+
+static void pasemi_mac_intf_enable(struct pasemi_mac *mac)
+{
+        unsigned int flags;
+
+        flags = read_mac_reg(mac, PAS_MAC_CFG_PCFG);
+        flags |= PAS_MAC_CFG_PCFG_PE;
+        write_mac_reg(mac, PAS_MAC_CFG_PCFG, flags);
+}
+
 static int pasemi_get_mac_addr(struct pasemi_mac *mac)
 {
         struct pci_dev *pdev = mac->pdev;
@@ -480,7 +500,7 @@ static void pasemi_mac_free_tx_resources(struct pasemi_mac *mac)
 
 }
 
-static void pasemi_mac_free_rx_resources(struct pasemi_mac *mac)
+static void pasemi_mac_free_rx_buffers(struct pasemi_mac *mac)
 {
         struct pasemi_mac_rxring *rx = rx_ring(mac);
         unsigned int i;
@@ -500,7 +520,12 @@ static void pasemi_mac_free_rx_resources(struct pasemi_mac *mac)
         }
 
         for (i = 0; i < RX_RING_SIZE; i++)
-                RX_DESC(rx, i) = 0;
+                RX_BUFF(rx, i) = 0;
+}
+
+static void pasemi_mac_free_rx_resources(struct pasemi_mac *mac)
+{
+        pasemi_mac_free_rx_buffers(mac);
 
         dma_free_coherent(&mac->dma_pdev->dev, RX_RING_SIZE * sizeof(u64),
                           rx_ring(mac)->buffers, rx_ring(mac)->buf_dma);
@@ -530,14 +555,14 @@ static void pasemi_mac_replenish_rx_ring(const struct net_device *dev,
                 /* Entry in use? */
                 WARN_ON(*buff);
 
-                skb = dev_alloc_skb(BUF_SIZE);
+                skb = dev_alloc_skb(mac->bufsz);
                 skb_reserve(skb, LOCAL_SKB_ALIGN);
 
                 if (unlikely(!skb))
                         break;
 
                 dma = pci_map_single(mac->dma_pdev, skb->data,
-                                     BUF_SIZE - LOCAL_SKB_ALIGN,
+                                     mac->bufsz - LOCAL_SKB_ALIGN,
                                      PCI_DMA_FROMDEVICE);
 
                 if (unlikely(dma_mapping_error(dma))) {
@@ -547,7 +572,7 @@ static void pasemi_mac_replenish_rx_ring(const struct net_device *dev,
 
                 info->skb = skb;
                 info->dma = dma;
-                *buff = XCT_RXB_LEN(BUF_SIZE) | XCT_RXB_ADDR(dma);
+                *buff = XCT_RXB_LEN(mac->bufsz) | XCT_RXB_ADDR(dma);
                 fill++;
         }
 
@@ -677,7 +702,7 @@ static int pasemi_mac_clean_rx(struct pasemi_mac_rxring *rx,
 
                 len = (macrx & XCT_MACRX_LLEN_M) >> XCT_MACRX_LLEN_S;
 
-                pci_unmap_single(pdev, dma, BUF_SIZE-LOCAL_SKB_ALIGN,
+                pci_unmap_single(pdev, dma, mac->bufsz - LOCAL_SKB_ALIGN,
                                  PCI_DMA_FROMDEVICE);
 
                 if (macrx & XCT_MACRX_CRC) {
@@ -901,24 +926,6 @@ static irqreturn_t pasemi_mac_tx_intr(int irq, void *data)
         return IRQ_HANDLED;
 }
 
-static void pasemi_mac_intf_disable(struct pasemi_mac *mac)
-{
-        unsigned int flags;
-
-        flags = read_mac_reg(mac, PAS_MAC_CFG_PCFG);
-        flags &= ~PAS_MAC_CFG_PCFG_PE;
-        write_mac_reg(mac, PAS_MAC_CFG_PCFG, flags);
-}
-
-static void pasemi_mac_intf_enable(struct pasemi_mac *mac)
-{
-        unsigned int flags;
-
-        flags = read_mac_reg(mac, PAS_MAC_CFG_PCFG);
-        flags |= PAS_MAC_CFG_PCFG_PE;
-        write_mac_reg(mac, PAS_MAC_CFG_PCFG, flags);
-}
-
 static void pasemi_adjust_link(struct net_device *dev)
 {
         struct pasemi_mac *mac = netdev_priv(dev);
@@ -1175,11 +1182,71 @@ out_rx_resources:
 
 #define MAX_RETRIES 5000
 
+static void pasemi_mac_pause_txchan(struct pasemi_mac *mac)
+{
+        unsigned int sta, retries;
+        int txch = tx_ring(mac)->chan.chno;
+
+        write_dma_reg(PAS_DMA_TXCHAN_TCMDSTA(txch),
+                      PAS_DMA_TXCHAN_TCMDSTA_ST);
+
+        for (retries = 0; retries < MAX_RETRIES; retries++) {
+                sta = read_dma_reg(PAS_DMA_TXCHAN_TCMDSTA(txch));
+                if (!(sta & PAS_DMA_TXCHAN_TCMDSTA_ACT))
+                        break;
+                cond_resched();
+        }
+
+        if (sta & PAS_DMA_TXCHAN_TCMDSTA_ACT)
+                dev_err(&mac->dma_pdev->dev,
+                        "Failed to stop tx channel, tcmdsta %08x\n", sta);
+
+        write_dma_reg(PAS_DMA_TXCHAN_TCMDSTA(txch), 0);
+}
+
+static void pasemi_mac_pause_rxchan(struct pasemi_mac *mac)
+{
+        unsigned int sta, retries;
+        int rxch = rx_ring(mac)->chan.chno;
+
+        write_dma_reg(PAS_DMA_RXCHAN_CCMDSTA(rxch),
+                      PAS_DMA_RXCHAN_CCMDSTA_ST);
+        for (retries = 0; retries < MAX_RETRIES; retries++) {
+                sta = read_dma_reg(PAS_DMA_RXCHAN_CCMDSTA(rxch));
+                if (!(sta & PAS_DMA_RXCHAN_CCMDSTA_ACT))
+                        break;
+                cond_resched();
+        }
+
+        if (sta & PAS_DMA_RXCHAN_CCMDSTA_ACT)
+                dev_err(&mac->dma_pdev->dev,
+                        "Failed to stop rx channel, ccmdsta 08%x\n", sta);
+        write_dma_reg(PAS_DMA_RXCHAN_CCMDSTA(rxch), 0);
+}
+
+static void pasemi_mac_pause_rxint(struct pasemi_mac *mac)
+{
+        unsigned int sta, retries;
+
+        write_dma_reg(PAS_DMA_RXINT_RCMDSTA(mac->dma_if),
+                      PAS_DMA_RXINT_RCMDSTA_ST);
+        for (retries = 0; retries < MAX_RETRIES; retries++) {
+                sta = read_dma_reg(PAS_DMA_RXINT_RCMDSTA(mac->dma_if));
+                if (!(sta & PAS_DMA_RXINT_RCMDSTA_ACT))
+                        break;
+                cond_resched();
+        }
+
+        if (sta & PAS_DMA_RXINT_RCMDSTA_ACT)
+                dev_err(&mac->dma_pdev->dev,
+                        "Failed to stop rx interface, rcmdsta %08x\n", sta);
+        write_dma_reg(PAS_DMA_RXINT_RCMDSTA(mac->dma_if), 0);
+}
+
 static int pasemi_mac_close(struct net_device *dev)
 {
         struct pasemi_mac *mac = netdev_priv(dev);
         unsigned int sta;
-        int retries;
         int rxch, txch;
 
         rxch = rx_ring(mac)->chan.chno;
@@ -1217,51 +1284,9 @@ static int pasemi_mac_close(struct net_device *dev)
         pasemi_mac_clean_tx(tx_ring(mac));
         pasemi_mac_clean_rx(rx_ring(mac), RX_RING_SIZE);
 
-        /* Disable interface */
-        write_dma_reg(PAS_DMA_TXCHAN_TCMDSTA(txch),
-                      PAS_DMA_TXCHAN_TCMDSTA_ST);
-        write_dma_reg( PAS_DMA_RXINT_RCMDSTA(mac->dma_if),
-                      PAS_DMA_RXINT_RCMDSTA_ST);
-        write_dma_reg(PAS_DMA_RXCHAN_CCMDSTA(rxch),
-                      PAS_DMA_RXCHAN_CCMDSTA_ST);
-
-        for (retries = 0; retries < MAX_RETRIES; retries++) {
-                sta = read_dma_reg(PAS_DMA_TXCHAN_TCMDSTA(rxch));
-                if (!(sta & PAS_DMA_TXCHAN_TCMDSTA_ACT))
-                        break;
-                cond_resched();
-        }
-
-        if (sta & PAS_DMA_TXCHAN_TCMDSTA_ACT)
-                dev_err(&mac->dma_pdev->dev, "Failed to stop tx channel\n");
-
-        for (retries = 0; retries < MAX_RETRIES; retries++) {
-                sta = read_dma_reg(PAS_DMA_RXCHAN_CCMDSTA(rxch));
-                if (!(sta & PAS_DMA_RXCHAN_CCMDSTA_ACT))
-                        break;
-                cond_resched();
-        }
-
-        if (sta & PAS_DMA_RXCHAN_CCMDSTA_ACT)
-                dev_err(&mac->dma_pdev->dev, "Failed to stop rx channel\n");
-
-        for (retries = 0; retries < MAX_RETRIES; retries++) {
-                sta = read_dma_reg(PAS_DMA_RXINT_RCMDSTA(mac->dma_if));
-                if (!(sta & PAS_DMA_RXINT_RCMDSTA_ACT))
-                        break;
-                cond_resched();
-        }
-
-        if (sta & PAS_DMA_RXINT_RCMDSTA_ACT)
-                dev_err(&mac->dma_pdev->dev, "Failed to stop rx interface\n");
-
-        /* Then, disable the channel. This must be done separately from
-         * stopping, since you can't disable when active.
-         */
-
-        write_dma_reg(PAS_DMA_TXCHAN_TCMDSTA(txch), 0);
-        write_dma_reg(PAS_DMA_RXCHAN_CCMDSTA(rxch), 0);
-        write_dma_reg(PAS_DMA_RXINT_RCMDSTA(mac->dma_if), 0);
+        pasemi_mac_pause_txchan(mac);
+        pasemi_mac_pause_rxint(mac);
+        pasemi_mac_pause_rxchan(mac);
 
         free_irq(mac->tx->chan.irq, mac->tx);
         free_irq(mac->rx->chan.irq, mac->rx);
@@ -1415,6 +1440,62 @@ static int pasemi_mac_poll(struct napi_struct *napi, int budget)
         return pkts;
 }
 
+static int pasemi_mac_change_mtu(struct net_device *dev, int new_mtu)
+{
+        struct pasemi_mac *mac = netdev_priv(dev);
+        unsigned int reg;
+        unsigned int rcmdsta;
+        int running;
+
+        if (new_mtu < PE_MIN_MTU || new_mtu > PE_MAX_MTU)
+                return -EINVAL;
+
+        running = netif_running(dev);
+
+        if (running) {
+                /* Need to stop the interface, clean out all already
+                 * received buffers, free all unused buffers on the RX
+                 * interface ring, then finally re-fill the rx ring with
+                 * the new-size buffers and restart.
+                 */
+
+                napi_disable(&mac->napi);
+                netif_tx_disable(dev);
+                pasemi_mac_intf_disable(mac);
+
+                rcmdsta = read_dma_reg(PAS_DMA_RXINT_RCMDSTA(mac->dma_if));
+                pasemi_mac_pause_rxint(mac);
+                pasemi_mac_clean_rx(rx_ring(mac), RX_RING_SIZE);
+                pasemi_mac_free_rx_buffers(mac);
+        }
+
+        /* Change maxf, i.e. what size frames are accepted.
+         * Need room for ethernet header and CRC word
+         */
+        reg = read_mac_reg(mac, PAS_MAC_CFG_MACCFG);
+        reg &= ~PAS_MAC_CFG_MACCFG_MAXF_M;
+        reg |= PAS_MAC_CFG_MACCFG_MAXF(new_mtu + ETH_HLEN + 4);
+        write_mac_reg(mac, PAS_MAC_CFG_MACCFG, reg);
+
+        dev->mtu = new_mtu;
+        /* MTU + ETH_HLEN + VLAN_HLEN + 2 64B cachelines */
+        mac->bufsz = new_mtu + ETH_HLEN + ETH_FCS_LEN + LOCAL_SKB_ALIGN + 128;
+
+        if (running) {
+                write_dma_reg(PAS_DMA_RXINT_RCMDSTA(mac->dma_if),
+                              rcmdsta | PAS_DMA_RXINT_RCMDSTA_EN);
+
+                rx_ring(mac)->next_to_fill = 0;
+                pasemi_mac_replenish_rx_ring(dev, RX_RING_SIZE-1);
+
+                napi_enable(&mac->napi);
+                netif_start_queue(dev);
+                pasemi_mac_intf_enable(mac);
+        }
+
+        return 0;
+}
+
 static int __devinit
 pasemi_mac_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 {
@@ -1503,6 +1584,11 @@ pasemi_mac_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
         dev->hard_start_xmit = pasemi_mac_start_tx;
         dev->set_multicast_list = pasemi_mac_set_rx_mode;
         dev->set_mac_address = pasemi_mac_set_mac_addr;
+        dev->mtu = PE_DEF_MTU;
+        /* 1500 MTU + ETH_HLEN + VLAN_HLEN + 2 64B cachelines */
+        mac->bufsz = dev->mtu + ETH_HLEN + ETH_FCS_LEN + LOCAL_SKB_ALIGN + 128;
+
+        dev->change_mtu = pasemi_mac_change_mtu;
 
         if (err)
                 goto out;