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Subject[PATCH v3 net-next 10/15] net: sgi: ioc3-eth: refactor rx buffer allocation
Date
Move common code for rx buffer setup into ioc3_alloc_skb and deal
with allocation failures. Also clean up allocation size calculation.

Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/ethernet/sgi/ioc3-eth.c | 95 ++++++++++++++++++-------------------
1 file changed, 45 insertions(+), 50 deletions(-)

diff --git a/drivers/net/ethernet/sgi/ioc3-eth.c b/drivers/net/ethernet/sgi/ioc3-eth.c
index fe8ee8f1c71f..7531944d2e95 100644
--- a/drivers/net/ethernet/sgi/ioc3-eth.c
+++ b/drivers/net/ethernet/sgi/ioc3-eth.c
@@ -11,11 +11,8 @@
*
* To do:
*
- * o Handle allocation failures in ioc3_alloc_skb() more gracefully.
- * o Handle allocation failures in ioc3_init_rings().
* o Use prefetching for large packets. What is a good lower limit for
* prefetching?
- * o We're probably allocating a bit too much memory.
* o Use hardware checksums.
* o Convert to using a IOC3 meta driver.
* o Which PHYs might possibly be attached to the IOC3 in real live,
@@ -72,6 +69,13 @@
#define TX_RING_ENTRIES 128
#define TX_RING_MASK (TX_RING_ENTRIES - 1)

+/* IOC3 does dma transfers in 128 byte blocks */
+#define IOC3_DMA_XFER_LEN 128UL
+
+/* Every RX buffer starts with 8 byte descriptor data */
+#define RX_OFFSET (sizeof(struct ioc3_erxbuf) + NET_IP_ALIGN)
+#define RX_BUF_SIZE (13 * IOC3_DMA_XFER_LEN)
+
#define ETCSR_FD ((17 << ETCSR_IPGR2_SHIFT) | (11 << ETCSR_IPGR1_SHIFT) | 21)
#define ETCSR_HD ((21 << ETCSR_IPGR2_SHIFT) | (21 << ETCSR_IPGR1_SHIFT) | 21)

@@ -108,36 +112,38 @@ static inline unsigned int ioc3_hash(const unsigned char *addr);
static void ioc3_start(struct ioc3_private *ip);
static inline void ioc3_stop(struct ioc3_private *ip);
static void ioc3_init(struct net_device *dev);
-static void ioc3_alloc_rx_bufs(struct net_device *dev);
+static int ioc3_alloc_rx_bufs(struct net_device *dev);
static void ioc3_free_rx_bufs(struct ioc3_private *ip);
static inline void ioc3_clean_tx_ring(struct ioc3_private *ip);

static const char ioc3_str[] = "IOC3 Ethernet";
static const struct ethtool_ops ioc3_ethtool_ops;

-/* We use this to acquire receive skb's that we can DMA directly into. */
-
-#define IOC3_CACHELINE 128UL

static inline unsigned long aligned_rx_skb_addr(unsigned long addr)
{
- return (~addr + 1) & (IOC3_CACHELINE - 1UL);
+ return (~addr + 1) & (IOC3_DMA_XFER_LEN - 1UL);
}

-static inline struct sk_buff *ioc3_alloc_skb(unsigned long length,
- unsigned int gfp_mask)
+static inline int ioc3_alloc_skb(struct sk_buff **skb, struct ioc3_erxbuf **rxb)
{
- struct sk_buff *skb;
+ struct sk_buff *new_skb;
+ int offset;

- skb = alloc_skb(length + IOC3_CACHELINE - 1, gfp_mask);
- if (likely(skb)) {
- int offset = aligned_rx_skb_addr((unsigned long)skb->data);
+ new_skb = alloc_skb(RX_BUF_SIZE + IOC3_DMA_XFER_LEN - 1, GFP_ATOMIC);
+ if (!new_skb)
+ return -ENOMEM;

- if (offset)
- skb_reserve(skb, offset);
- }
+ /* ensure buffer is aligned to IOC3_DMA_XFER_LEN */
+ offset = aligned_rx_skb_addr((unsigned long)new_skb->data);
+ if (offset)
+ skb_reserve(new_skb, offset);
+
+ *rxb = (struct ioc3_erxbuf *)new_skb->data;
+ skb_reserve(new_skb, RX_OFFSET);
+ *skb = new_skb;

- return skb;
+ return 0;
}

static inline unsigned long ioc3_map(void *ptr, unsigned long vdev)
@@ -151,13 +157,6 @@ static inline unsigned long ioc3_map(void *ptr, unsigned long vdev)
return virt_to_bus(ptr);
#endif
}
-
-/* BEWARE: The IOC3 documentation documents the size of rx buffers as
- * 1644 while it's actually 1664. This one was nasty to track down ...
- */
-#define RX_OFFSET 10
-#define RX_BUF_ALLOC_SIZE (1664 + RX_OFFSET + IOC3_CACHELINE)
-
#define IOC3_SIZE 0x100000

static inline u32 mcr_pack(u32 pulse, u32 sample)
@@ -538,11 +537,10 @@ static inline void ioc3_rx(struct net_device *dev)
err = be32_to_cpu(rxb->err); /* It's valid ... */
if (err & ERXBUF_GOODPKT) {
len = ((w0 >> ERXBUF_BYTECNT_SHIFT) & 0x7ff) - 4;
- skb_trim(skb, len);
+ skb_put(skb, len);
skb->protocol = eth_type_trans(skb, dev);

- new_skb = ioc3_alloc_skb(RX_BUF_ALLOC_SIZE, GFP_ATOMIC);
- if (!new_skb) {
+ if (ioc3_alloc_skb(&new_skb, &rxb)) {
/* Ouch, drop packet and just recycle packet
* to keep the ring filled.
*/
@@ -560,11 +558,6 @@ static inline void ioc3_rx(struct net_device *dev)

ip->rx_skbs[rx_entry] = NULL; /* Poison */

- /* Because we reserve afterwards. */
- skb_put(new_skb, (1664 + RX_OFFSET));
- rxb = (struct ioc3_erxbuf *)new_skb->data;
- skb_reserve(new_skb, RX_OFFSET);
-
dev->stats.rx_packets++; /* Statistics */
dev->stats.rx_bytes += len;
} else {
@@ -667,7 +660,11 @@ static void ioc3_error(struct net_device *dev, u32 eisr)
ioc3_clean_tx_ring(ip);

ioc3_init(dev);
- ioc3_alloc_rx_bufs(dev);
+ if (ioc3_alloc_rx_bufs(dev)) {
+ netdev_err(dev, "%s: rx buffer allocation failed\n", __func__);
+ spin_unlock(&ip->ioc3_lock);
+ return;
+ }
ioc3_start(ip);
ioc3_mii_init(ip);

@@ -801,7 +798,7 @@ static void ioc3_free_rx_bufs(struct ioc3_private *ip)
}
}

-static void ioc3_alloc_rx_bufs(struct net_device *dev)
+static int ioc3_alloc_rx_bufs(struct net_device *dev)
{
struct ioc3_private *ip = netdev_priv(dev);
struct ioc3_erxbuf *rxb;
@@ -812,25 +809,16 @@ static void ioc3_alloc_rx_bufs(struct net_device *dev)
* this for performance and memory later.
*/
for (i = 0; i < RX_BUFFS; i++) {
- struct sk_buff *skb;
-
- skb = ioc3_alloc_skb(RX_BUF_ALLOC_SIZE, GFP_ATOMIC);
- if (!skb) {
- show_free_areas(0, NULL);
- continue;
- }
-
- ip->rx_skbs[i] = skb;
+ if (ioc3_alloc_skb(&ip->rx_skbs[i], &rxb))
+ return -ENOMEM;

- /* Because we reserve afterwards. */
- skb_put(skb, (1664 + RX_OFFSET));
- rxb = (struct ioc3_erxbuf *)skb->data;
rxb->w0 = 0; /* Clear valid flag */
ip->rxr[i] = cpu_to_be64(ioc3_map(rxb, 1));
- skb_reserve(skb, RX_OFFSET);
}
ip->rx_ci = 0;
ip->rx_pi = RX_BUFFS;
+
+ return 0;
}

static inline void ioc3_ssram_disc(struct ioc3_private *ip)
@@ -942,7 +930,10 @@ static int ioc3_open(struct net_device *dev)
ip->ehar_l = 0;

ioc3_init(dev);
- ioc3_alloc_rx_bufs(dev);
+ if (ioc3_alloc_rx_bufs(dev)) {
+ netdev_err(dev, "%s: rx buffer allocation failed\n", __func__);
+ return -ENOMEM;
+ }
ioc3_start(ip);
ioc3_mii_start(ip);

@@ -1435,7 +1426,11 @@ static void ioc3_timeout(struct net_device *dev)
ioc3_clean_tx_ring(ip);

ioc3_init(dev);
- ioc3_alloc_rx_bufs(dev);
+ if (ioc3_alloc_rx_bufs(dev)) {
+ netdev_err(dev, "%s: rx buffer allocation failed\n", __func__);
+ spin_unlock_irq(&ip->ioc3_lock);
+ return;
+ }
ioc3_start(ip);
ioc3_mii_init(ip);
ioc3_mii_start(ip);
--
2.13.7
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