[PATCH] tilepro ethernet driver: fix a few minor issues
From: Chris Metcalf <hidden>
Date: 2012-03-30 23:25:53
This commit fixes a number of issues seen with the driver: - Improve handling of return credits to the hardware shim - Use skb_frag_size() appropriately - Add netpoll support to run console over UDP Signed-off-by: Chris Metcalf <redacted> --- drivers/net/ethernet/tile/tilepro.c | 75 +++++++++++++++++++++++------------ 1 files changed, 50 insertions(+), 25 deletions(-)
diff --git a/drivers/net/ethernet/tile/tilepro.c b/drivers/net/ethernet/tile/tilepro.c
index d9951af..eb4ea08 100644
--- a/drivers/net/ethernet/tile/tilepro.c
+++ b/drivers/net/ethernet/tile/tilepro.c@@ -342,6 +342,21 @@ inline int __netio_fastio1(u32 fastio_index, u32 arg0) } +static void tile_net_return_credit(struct tile_net_cpu *info) +{ + struct tile_netio_queue *queue = &info->queue; + netio_queue_user_impl_t *qup = &queue->__user_part; + + /* Return four credits after every fourth packet. */ + if (--qup->__receive_credit_remaining == 0) { + u32 interval = qup->__receive_credit_interval; + qup->__receive_credit_remaining = interval; + __netio_fastio_return_credits(qup->__fastio_index, interval); + } +} + + + /* * Provide a linux buffer to LIPP. */
@@ -864,19 +879,11 @@ static bool tile_net_poll_aux(struct tile_net_cpu *info, int index) stats->rx_packets++; stats->rx_bytes += len; - - if (small) - info->num_needed_small_buffers++; - else - info->num_needed_large_buffers++; } - /* Return four credits after every fourth packet. */ - if (--qup->__receive_credit_remaining == 0) { - u32 interval = qup->__receive_credit_interval; - qup->__receive_credit_remaining = interval; - __netio_fastio_return_credits(qup->__fastio_index, interval); - } + /* ISSUE: It would be nice to defer this until the packet has */ + /* actually been processed. */ + tile_net_return_credit(info); /* Consume this packet. */ qup->__packet_receive_read = index2;
@@ -1543,7 +1550,7 @@ static int tile_net_drain_lipp_buffers(struct tile_net_priv *priv) /* Drain all the LIPP buffers. */ while (true) { - int buffer; + unsigned int buffer; /* NOTE: This should never fail. */ if (hv_dev_pread(priv->hv_devhdl, 0, (HV_VirtAddr)&buffer,
@@ -1707,7 +1714,7 @@ static unsigned int tile_net_tx_frags(lepp_frag_t *frags, if (!hash_default) { void *va = pfn_to_kaddr(pfn) + f->page_offset; BUG_ON(PageHighMem(skb_frag_page(f))); - finv_buffer_remote(va, f->size, 0); + finv_buffer_remote(va, skb_frag_size(f), 0); } cpa = ((phys_addr_t)pfn << PAGE_SHIFT) + f->page_offset;
@@ -1735,8 +1742,8 @@ static unsigned int tile_net_tx_frags(lepp_frag_t *frags, * Sometimes, if "sendfile()" requires copying, we will be called with * "data" containing the header and payload, with "frags" being empty. * - * In theory, "sh->nr_frags" could be 3, but in practice, it seems - * that this will never actually happen. + * Sometimes, for example when using NFS over TCP, a single segment can + * span 3 fragments, which must be handled carefully in LEPP. * * See "emulate_large_send_offload()" for some reference code, which * does not handle checksumming.
@@ -1844,10 +1851,8 @@ static int tile_net_tx_tso(struct sk_buff *skb, struct net_device *dev) spin_lock_irqsave(&priv->eq_lock, irqflags); - /* - * Handle completions if needed to make room. - * HACK: Spin until there is sufficient room. - */ + /* Handle completions if needed to make room. */ + /* NOTE: Return NETDEV_TX_BUSY if there is still no room. */ if (lepp_num_free_comp_slots(eq) == 0) { nolds = tile_net_lepp_grab_comps(eq, olds, wanted, 0); if (nolds == 0) {
@@ -1861,6 +1866,7 @@ busy: cmd_tail = eq->cmd_tail; /* Prepare to advance, detecting full queue. */ + /* NOTE: Return NETDEV_TX_BUSY if the queue is full. */ cmd_next = cmd_tail + cmd_size; if (cmd_tail < cmd_head && cmd_next >= cmd_head) goto busy;
@@ -2023,10 +2029,8 @@ static int tile_net_tx(struct sk_buff *skb, struct net_device *dev) spin_lock_irqsave(&priv->eq_lock, irqflags); - /* - * Handle completions if needed to make room. - * HACK: Spin until there is sufficient room. - */ + /* Handle completions if needed to make room. */ + /* NOTE: Return NETDEV_TX_BUSY if there is still no room. */ if (lepp_num_free_comp_slots(eq) == 0) { nolds = tile_net_lepp_grab_comps(eq, olds, wanted, 0); if (nolds == 0) {
@@ -2040,6 +2044,7 @@ busy: cmd_tail = eq->cmd_tail; /* Copy the commands, or fail. */ + /* NOTE: Return NETDEV_TX_BUSY if the queue is full. */ for (i = 0; i < num_frags; i++) { /* Prepare to advance, detecting full queue. */
@@ -2260,6 +2265,23 @@ static int tile_net_get_mac(struct net_device *dev) return 0; } + +#ifdef CONFIG_NET_POLL_CONTROLLER +/* + * Polling 'interrupt' - used by things like netconsole to send skbs + * without having to re-enable interrupts. It's not called while + * the interrupt routine is executing. + */ +static void tile_net_netpoll(struct net_device *dev) +{ + struct tile_net_priv *priv = netdev_priv(dev); + disable_percpu_irq(priv->intr_id); + tile_net_handle_ingress_interrupt(priv->intr_id, dev); + enable_percpu_irq(priv->intr_id, 0); +} +#endif + + static const struct net_device_ops tile_net_ops = { .ndo_open = tile_net_open, .ndo_stop = tile_net_stop,
@@ -2268,7 +2290,10 @@ static const struct net_device_ops tile_net_ops = { .ndo_get_stats = tile_net_get_stats, .ndo_change_mtu = tile_net_change_mtu, .ndo_tx_timeout = tile_net_tx_timeout, - .ndo_set_mac_address = tile_net_set_mac_address + .ndo_set_mac_address = tile_net_set_mac_address, +#ifdef CONFIG_NET_POLL_CONTROLLER + .ndo_poll_controller = tile_net_netpoll, +#endif };
@@ -2408,7 +2433,7 @@ static void tile_net_cleanup(void) */ static int tile_net_init_module(void) { - pr_info("Tilera IPP Net Driver\n"); + pr_info("Tilera Network Driver\n"); tile_net_devs[0] = tile_net_dev_init("xgbe0"); tile_net_devs[1] = tile_net_dev_init("xgbe1");
--
1.6.5.2