SGISEEQ: use cached memory access to make driver work on IP28

SGI IP28 machines would need special treatment (enable adding addtional
wait states) when accessing memory uncached. To avoid this pain I changed
the driver to use only cached access to memory.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 166 insertions, 73 deletions

diff --git a/drivers/net/sgiseeq.c b/drivers/net/sgiseeq.c
index ff4056310356..3145ca13d255 100644
--- a/drivers/net/sgiseeq.c
+++ b/drivers/net/sgiseeq.c
@@ -12,7 +12,6 @@
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/interrupt.h>
-#include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/delay.h>
 #include <linux/netdevice.h>
@@ -53,14 +52,35 @@ static char *sgiseeqstr = "SGI Seeq8003";
                             sp->tx_old + (SEEQ_TX_BUFFERS - 1) - sp->tx_new : \
                             sp->tx_old - sp->tx_new - 1)
 
+#define VIRT_TO_DMA(sp, v) ((sp)->srings_dma +                                 \
+                                  (dma_addr_t)((unsigned long)(v) -            \
+                                               (unsigned long)((sp)->rx_desc)))
+
+#define DMA_SYNC_DESC_CPU(dev, addr) \
+        do { dma_cache_sync((dev)->dev.parent, (void *)addr, \
+             sizeof(struct sgiseeq_rx_desc), DMA_FROM_DEVICE); } while (0)
+
+#define DMA_SYNC_DESC_DEV(dev, addr) \
+        do { dma_cache_sync((dev)->dev.parent, (void *)addr, \
+             sizeof(struct sgiseeq_rx_desc), DMA_TO_DEVICE); } while (0)
+
+/* Copy frames shorter than rx_copybreak, otherwise pass on up in
+ * a full sized sk_buff.  Value of 100 stolen from tulip.c (!alpha).
+ */
+static int rx_copybreak = 100;
+
+#define PAD_SIZE    (128 - sizeof(struct hpc_dma_desc) - sizeof(void *))
+
 struct sgiseeq_rx_desc {
         volatile struct hpc_dma_desc rdma;
-        volatile signed int buf_vaddr;
+        u8 padding[PAD_SIZE];
+        struct sk_buff *skb;
 };
 
 struct sgiseeq_tx_desc {
         volatile struct hpc_dma_desc tdma;
-        volatile signed int buf_vaddr;
+        u8 padding[PAD_SIZE];
+        struct sk_buff *skb;
 };
 
 /*
@@ -163,35 +183,55 @@ static int seeq_init_ring(struct net_device *dev)
 
         /* Setup tx ring. */
         for(i = 0; i < SEEQ_TX_BUFFERS; i++) {
-                if (!sp->tx_desc[i].tdma.pbuf) {
-                        unsigned long buffer;
-
-                        buffer = (unsigned long) kmalloc(PKT_BUF_SZ, GFP_KERNEL);
-                        if (!buffer)
-                                return -ENOMEM;
-                        sp->tx_desc[i].buf_vaddr = CKSEG1ADDR(buffer);
-                        sp->tx_desc[i].tdma.pbuf = CPHYSADDR(buffer);
-                }
                 sp->tx_desc[i].tdma.cntinfo = TCNTINFO_INIT;
+                DMA_SYNC_DESC_DEV(dev, &sp->tx_desc[i]);
         }
 
         /* And now the rx ring. */
         for (i = 0; i < SEEQ_RX_BUFFERS; i++) {
                 if (!sp->rx_desc[i].rdma.pbuf) {
-                        unsigned long buffer;
+                        dma_addr_t dma_addr;
+                        struct sk_buff *skb = netdev_alloc_skb(dev, PKT_BUF_SZ);
 
-                        buffer = (unsigned long) kmalloc(PKT_BUF_SZ, GFP_KERNEL);
-                        if (!buffer)
+                        if (skb == NULL)
                                 return -ENOMEM;
-                        sp->rx_desc[i].buf_vaddr = CKSEG1ADDR(buffer);
-                        sp->rx_desc[i].rdma.pbuf = CPHYSADDR(buffer);
+                        skb_reserve(skb, 2);
+                        dma_addr = dma_map_single(dev->dev.parent,
+                                                  skb->data - 2,
+                                                  PKT_BUF_SZ, DMA_FROM_DEVICE);
+                        sp->rx_desc[i].skb = skb;
+                        sp->rx_desc[i].rdma.pbuf = dma_addr;
                 }
                 sp->rx_desc[i].rdma.cntinfo = RCNTINFO_INIT;
+                DMA_SYNC_DESC_DEV(dev, &sp->rx_desc[i]);
         }
         sp->rx_desc[i - 1].rdma.cntinfo |= HPCDMA_EOR;
+        DMA_SYNC_DESC_DEV(dev, &sp->rx_desc[i - 1]);
         return 0;
 }
 
+static void seeq_purge_ring(struct net_device *dev)
+{
+        struct sgiseeq_private *sp = netdev_priv(dev);
+        int i;
+
+        /* clear tx ring. */
+        for (i = 0; i < SEEQ_TX_BUFFERS; i++) {
+                if (sp->tx_desc[i].skb) {
+                        dev_kfree_skb(sp->tx_desc[i].skb);
+                        sp->tx_desc[i].skb = NULL;
+                }
+        }
+
+        /* And now the rx ring. */
+        for (i = 0; i < SEEQ_RX_BUFFERS; i++) {
+                if (sp->rx_desc[i].skb) {
+                        dev_kfree_skb(sp->rx_desc[i].skb);
+                        sp->rx_desc[i].skb = NULL;
+                }
+        }
+}
+
 #ifdef DEBUG
 static struct sgiseeq_private *gpriv;
 static struct net_device *gdev;
@@ -258,8 +298,8 @@ static int init_seeq(struct net_device *dev, struct sgiseeq_private *sp,
                 sregs->tstat = TSTAT_INIT_SEEQ;
         }
 
-        hregs->rx_ndptr = CPHYSADDR(sp->rx_desc);
-        hregs->tx_ndptr = CPHYSADDR(sp->tx_desc);
+        hregs->rx_ndptr = VIRT_TO_DMA(sp, sp->rx_desc);
+        hregs->tx_ndptr = VIRT_TO_DMA(sp, sp->tx_desc);
 
         seeq_go(sp, hregs, sregs);
         return 0;
@@ -283,69 +323,90 @@ static inline void rx_maybe_restart(struct sgiseeq_private *sp,
                                     struct sgiseeq_regs *sregs)
 {
         if (!(hregs->rx_ctrl & HPC3_ERXCTRL_ACTIVE)) {
-                hregs->rx_ndptr = CPHYSADDR(sp->rx_desc + sp->rx_new);
+                hregs->rx_ndptr = VIRT_TO_DMA(sp, sp->rx_desc + sp->rx_new);
                 seeq_go(sp, hregs, sregs);
         }
 }
 
-#define for_each_rx(rd, sp) for((rd) = &(sp)->rx_desc[(sp)->rx_new]; \
-                                !((rd)->rdma.cntinfo & HPCDMA_OWN); \
-                                (rd) = &(sp)->rx_desc[(sp)->rx_new])
-
 static inline void sgiseeq_rx(struct net_device *dev, struct sgiseeq_private *sp,
                               struct hpc3_ethregs *hregs,
                               struct sgiseeq_regs *sregs)
 {
         struct sgiseeq_rx_desc *rd;
         struct sk_buff *skb = NULL;
+        struct sk_buff *newskb;
         unsigned char pkt_status;
-        unsigned char *pkt_pointer = NULL;
         int len = 0;
         unsigned int orig_end = PREV_RX(sp->rx_new);
 
         /* Service every received packet. */
-        for_each_rx(rd, sp) {
+        rd = &sp->rx_desc[sp->rx_new];
+        DMA_SYNC_DESC_CPU(dev, rd);
+        while (!(rd->rdma.cntinfo & HPCDMA_OWN)) {
                 len = PKT_BUF_SZ - (rd->rdma.cntinfo & HPCDMA_BCNT) - 3;
-                pkt_pointer = (unsigned char *)(long)rd->buf_vaddr;
-                pkt_status = pkt_pointer[len + 2];
-
+                dma_unmap_single(dev->dev.parent, rd->rdma.pbuf,
+                                 PKT_BUF_SZ, DMA_FROM_DEVICE);
+                pkt_status = rd->skb->data[len];
                 if (pkt_status & SEEQ_RSTAT_FIG) {
                         /* Packet is OK. */
-                        skb = dev_alloc_skb(len + 2);
-
-                        if (skb) {
-                                skb_reserve(skb, 2);
-                                skb_put(skb, len);
-
-                                /* Copy out of kseg1 to avoid silly cache flush. */
-                                skb_copy_to_linear_data(skb, pkt_pointer + 2, len);
-                                skb->protocol = eth_type_trans(skb, dev);
-
-                                /* We don't want to receive our own packets */
-                                if (memcmp(eth_hdr(skb)->h_source, dev->dev_addr, ETH_ALEN)) {
+                        /* We don't want to receive our own packets */
+                        if (memcmp(rd->skb->data + 6, dev->dev_addr, ETH_ALEN)) {
+                                if (len > rx_copybreak) {
+                                        skb = rd->skb;
+                                        newskb = netdev_alloc_skb(dev, PKT_BUF_SZ);
+                                        if (!newskb) {
+                                                newskb = skb;
+                                                skb = NULL;
+                                                goto memory_squeeze;
+                                        }
+                                        skb_reserve(newskb, 2);
+                                } else {
+                                        skb = netdev_alloc_skb(dev, len + 2);
+                                        if (skb) {
+                                                skb_reserve(skb, 2);
+                                                skb_copy_to_linear_data(skb, rd->skb->data, len);
+                                        }
+                                        newskb = rd->skb;
+                                }
+memory_squeeze:
+                                if (skb) {
+                                        skb_put(skb, len);
+                                        skb->protocol = eth_type_trans(skb, dev);
                                         netif_rx(skb);
                                         dev->last_rx = jiffies;
                                         dev->stats.rx_packets++;
                                         dev->stats.rx_bytes += len;
                                 } else {
-                                        /* Silently drop my own packets */
-                                        dev_kfree_skb_irq(skb);
+                                        printk(KERN_NOTICE "%s: Memory squeeze, deferring packet.\n",
+                                                dev->name);
+                                        dev->stats.rx_dropped++;
                                 }
                         } else {
-                                printk (KERN_NOTICE "%s: Memory squeeze, deferring packet.\n",
-                                        dev->name);
-                                dev->stats.rx_dropped++;
+                                /* Silently drop my own packets */
+                                newskb = rd->skb;
                         }
                 } else {
                         record_rx_errors(dev, pkt_status);
+                        newskb = rd->skb;
                 }
+                rd->skb = newskb;
+                rd->rdma.pbuf = dma_map_single(dev->dev.parent,
+                                               newskb->data - 2,
+                                               PKT_BUF_SZ, DMA_FROM_DEVICE);
 
                 /* Return the entry to the ring pool. */
                 rd->rdma.cntinfo = RCNTINFO_INIT;
                 sp->rx_new = NEXT_RX(sp->rx_new);
+                DMA_SYNC_DESC_DEV(dev, rd);
+                rd = &sp->rx_desc[sp->rx_new];
+                DMA_SYNC_DESC_CPU(dev, rd);
         }
+        DMA_SYNC_DESC_CPU(dev, &sp->rx_desc[orig_end]);
         sp->rx_desc[orig_end].rdma.cntinfo &= ~(HPCDMA_EOR);
+        DMA_SYNC_DESC_DEV(dev, &sp->rx_desc[orig_end]);
+        DMA_SYNC_DESC_CPU(dev, &sp->rx_desc[PREV_RX(sp->rx_new)]);
         sp->rx_desc[PREV_RX(sp->rx_new)].rdma.cntinfo |= HPCDMA_EOR;
+        DMA_SYNC_DESC_DEV(dev, &sp->rx_desc[PREV_RX(sp->rx_new)]);
         rx_maybe_restart(sp, hregs, sregs);
 }
 
@@ -358,20 +419,29 @@ static inline void tx_maybe_reset_collisions(struct sgiseeq_private *sp,
         }
 }
 
-static inline void kick_tx(struct sgiseeq_tx_desc *td,
+static inline void kick_tx(struct net_device *dev,
+                           struct sgiseeq_private *sp,
                            struct hpc3_ethregs *hregs)
 {
+        struct sgiseeq_tx_desc *td;
+        int i = sp->tx_old;
+
         /* If the HPC aint doin nothin, and there are more packets
          * with ETXD cleared and XIU set we must make very certain
          * that we restart the HPC else we risk locking up the
          * adapter.  The following code is only safe iff the HPCDMA
          * is not active!
          */
+        td = &sp->tx_desc[i];
+        DMA_SYNC_DESC_CPU(dev, td);
         while ((td->tdma.cntinfo & (HPCDMA_XIU | HPCDMA_ETXD)) ==
-              (HPCDMA_XIU | HPCDMA_ETXD))
-                td = (struct sgiseeq_tx_desc *)(long) CKSEG1ADDR(td->tdma.pnext);
+              (HPCDMA_XIU | HPCDMA_ETXD)) {
+                i = NEXT_TX(i);
+                td = &sp->tx_desc[i];
+                DMA_SYNC_DESC_CPU(dev, td);
+        }
         if (td->tdma.cntinfo & HPCDMA_XIU) {
-                hregs->tx_ndptr = CPHYSADDR(td);
+                hregs->tx_ndptr = VIRT_TO_DMA(sp, td);
                 hregs->tx_ctrl = HPC3_ETXCTRL_ACTIVE;
         }
 }
@@ -400,11 +470,12 @@ static inline void sgiseeq_tx(struct net_device *dev, struct sgiseeq_private *sp
         for (j = sp->tx_old; j != sp->tx_new; j = NEXT_TX(j)) {
                 td = &sp->tx_desc[j];
 
+                DMA_SYNC_DESC_CPU(dev, td);
                 if (!(td->tdma.cntinfo & (HPCDMA_XIU)))
                         break;
                 if (!(td->tdma.cntinfo & (HPCDMA_ETXD))) {
                         if (!(status & HPC3_ETXCTRL_ACTIVE)) {
-                                hregs->tx_ndptr = CPHYSADDR(td);
+                                hregs->tx_ndptr = VIRT_TO_DMA(sp, td);
                                 hregs->tx_ctrl = HPC3_ETXCTRL_ACTIVE;
                         }
                         break;
@@ -413,6 +484,11 @@ static inline void sgiseeq_tx(struct net_device *dev, struct sgiseeq_private *sp
                 sp->tx_old = NEXT_TX(sp->tx_old);
                 td->tdma.cntinfo &= ~(HPCDMA_XIU | HPCDMA_XIE);
                 td->tdma.cntinfo |= HPCDMA_EOX;
+                if (td->skb) {
+                        dev_kfree_skb_any(td->skb);
+                        td->skb = NULL;
+                }
+                DMA_SYNC_DESC_DEV(dev, td);
         }
 }
 
@@ -480,6 +556,7 @@ static int sgiseeq_close(struct net_device *dev)
         /* Shutdown the Seeq. */
         reset_hpc3_and_seeq(sp->hregs, sregs);
         free_irq(irq, dev);
+        seeq_purge_ring(dev);
 
         return 0;
 }
@@ -506,16 +583,22 @@ static int sgiseeq_start_xmit(struct sk_buff *skb, struct net_device *dev)
         struct hpc3_ethregs *hregs = sp->hregs;
         unsigned long flags;
         struct sgiseeq_tx_desc *td;
-        int skblen, len, entry;
+        int len, entry;
 
         spin_lock_irqsave(&sp->tx_lock, flags);
 
         /* Setup... */
-        skblen = skb->len;
-        len = (skblen <= ETH_ZLEN) ? ETH_ZLEN : skblen;
+        len = skb->len;
+        if (len < ETH_ZLEN) {
+                if (skb_padto(skb, ETH_ZLEN))
+                        return 0;
+                len = ETH_ZLEN;
+        }
+
         dev->stats.tx_bytes += len;
         entry = sp->tx_new;
         td = &sp->tx_desc[entry];
+        DMA_SYNC_DESC_CPU(dev, td);
 
         /* Create entry.  There are so many races with adding a new
          * descriptor to the chain:
@@ -530,25 +613,27 @@ static int sgiseeq_start_xmit(struct sk_buff *skb, struct net_device *dev)
          *    entry and the HPC got to the end of the chain before we
          *    added this new entry and restarted it.
          */
-        skb_copy_from_linear_data(skb, (char *)(long)td->buf_vaddr, skblen);
-        if (len != skblen)
-                memset((char *)(long)td->buf_vaddr + skb->len, 0, len-skblen);
+        td->skb = skb;
+        td->tdma.pbuf = dma_map_single(dev->dev.parent, skb->data,
+                                       len, DMA_TO_DEVICE);
         td->tdma.cntinfo = (len & HPCDMA_BCNT) |
                            HPCDMA_XIU | HPCDMA_EOXP | HPCDMA_XIE | HPCDMA_EOX;
+        DMA_SYNC_DESC_DEV(dev, td);
         if (sp->tx_old != sp->tx_new) {
                 struct sgiseeq_tx_desc *backend;
 
                 backend = &sp->tx_desc[PREV_TX(sp->tx_new)];
+                DMA_SYNC_DESC_CPU(dev, backend);
                 backend->tdma.cntinfo &= ~HPCDMA_EOX;
+                DMA_SYNC_DESC_DEV(dev, backend);
         }
         sp->tx_new = NEXT_TX(sp->tx_new); /* Advance. */
 
         /* Maybe kick the HPC back into motion. */
         if (!(hregs->tx_ctrl & HPC3_ETXCTRL_ACTIVE))
-                kick_tx(&sp->tx_desc[sp->tx_old], hregs);
+                kick_tx(dev, sp, hregs);
 
         dev->trans_start = jiffies;
-        dev_kfree_skb(skb);
 
         if (!TX_BUFFS_AVAIL(sp))
                 netif_stop_queue(dev);
@@ -586,33 +671,41 @@ static void sgiseeq_set_multicast(struct net_device *dev)
                 sgiseeq_reset(dev);
 }
 
-static inline void setup_tx_ring(struct sgiseeq_tx_desc *buf, int nbufs)
+static inline void setup_tx_ring(struct net_device *dev,
+                                 struct sgiseeq_tx_desc *buf,
+                                 int nbufs)
 {
+        struct sgiseeq_private *sp = netdev_priv(dev);
         int i = 0;
 
         while (i < (nbufs - 1)) {
-                buf[i].tdma.pnext = CPHYSADDR(buf + i + 1);
+                buf[i].tdma.pnext = VIRT_TO_DMA(sp, buf + i + 1);
                 buf[i].tdma.pbuf = 0;
+                DMA_SYNC_DESC_DEV(dev, &buf[i]);
                 i++;
         }
-        buf[i].tdma.pnext = CPHYSADDR(buf);
+        buf[i].tdma.pnext = VIRT_TO_DMA(sp, buf);
+        DMA_SYNC_DESC_DEV(dev, &buf[i]);
 }
 
-static inline void setup_rx_ring(struct sgiseeq_rx_desc *buf, int nbufs)
+static inline void setup_rx_ring(struct net_device *dev,
+                                 struct sgiseeq_rx_desc *buf,
+                                 int nbufs)
 {
+        struct sgiseeq_private *sp = netdev_priv(dev);
         int i = 0;
 
         while (i < (nbufs - 1)) {
-                buf[i].rdma.pnext = CPHYSADDR(buf + i + 1);
+                buf[i].rdma.pnext = VIRT_TO_DMA(sp, buf + i + 1);
                 buf[i].rdma.pbuf = 0;
+                DMA_SYNC_DESC_DEV(dev, &buf[i]);
                 i++;
         }
         buf[i].rdma.pbuf = 0;
-        buf[i].rdma.pnext = CPHYSADDR(buf);
+        buf[i].rdma.pnext = VIRT_TO_DMA(sp, buf);
+        DMA_SYNC_DESC_DEV(dev, &buf[i]);
 }
 
-#define ALIGNED(x)  ((((unsigned long)(x)) + 0xf) & ~(0xf))
-
 static int __init sgiseeq_probe(struct platform_device *pdev)
 {
         struct sgiseeq_platform_data *pd = pdev->dev.platform_data;
@@ -621,7 +714,7 @@ static int __init sgiseeq_probe(struct platform_device *pdev)
         unsigned int irq = pd->irq;
         struct sgiseeq_private *sp;
         struct net_device *dev;
-        int err, i;
+        int err;
         DECLARE_MAC_BUF(mac);
 
         dev = alloc_etherdev(sizeof (struct sgiseeq_private));
@@ -635,7 +728,7 @@ static int __init sgiseeq_probe(struct platform_device *pdev)
         sp = netdev_priv(dev);
 
         /* Make private data page aligned */
-        sr = dma_alloc_coherent(&pdev->dev, sizeof(*sp->srings),
+        sr = dma_alloc_noncoherent(&pdev->dev, sizeof(*sp->srings),
                                 &sp->srings_dma, GFP_KERNEL);
         if (!sr) {
                 printk(KERN_ERR "Sgiseeq: Page alloc failed, aborting.\n");
@@ -647,8 +740,8 @@ static int __init sgiseeq_probe(struct platform_device *pdev)
         sp->tx_desc = sp->srings->txvector;
 
         /* A couple calculations now, saves many cycles later. */
-        setup_rx_ring(sp->rx_desc, SEEQ_RX_BUFFERS);
-        setup_tx_ring(sp->tx_desc, SEEQ_TX_BUFFERS);
+        setup_rx_ring(dev, sp->rx_desc, SEEQ_RX_BUFFERS);
+        setup_tx_ring(dev, sp->tx_desc, SEEQ_TX_BUFFERS);
 
         memcpy(dev->dev_addr, pd->mac, ETH_ALEN);
 
@@ -716,8 +809,8 @@ static int __exit sgiseeq_remove(struct platform_device *pdev)
         struct sgiseeq_private *sp = netdev_priv(dev);
 
         unregister_netdev(dev);
-        dma_free_coherent(&pdev->dev, sizeof(*sp->srings), sp->srings,
-                          sp->srings_dma);
+        dma_free_noncoherent(&pdev->dev, sizeof(*sp->srings), sp->srings,
+                             sp->srings_dma);
         free_netdev(dev);
         platform_set_drvdata(pdev, NULL);