Refactoring:
- convert next_tx/rx counter into dma_fifo member fifo->next - use POLL_TIME define instead of magic number 100 - remove obsolete tx_fifo_full()
This commit is contained in:
Patrick Bruenn
parent
2fb819d6f4
commit
6c129ee7ce
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@ -91,14 +91,14 @@ extern int ccat_dma_init(struct ccat_dma *const dma, size_t channel,
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* @data: the bytes of the ethernet frame
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*/
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struct ccat_eth_frame {
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u32 reserved1;
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u32 received:1;
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u32 reserved2:31;
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u16 length;
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u16 reserved3;
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u32 sent:1;
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u32 reserved4:31;
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u64 timestamp;
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__le32 reserved1;
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__le32 rx_flags;
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#define CCAT_FRAME_RECEIVED 0x1
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__le16 length;
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__le16 reserved3;
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__le32 tx_flags;
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#define CCAT_FRAME_SENT 0x1
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__le64 timestamp;
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u8 data[0x800 - 3 * sizeof(u64)];
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#define CCAT_ETH_FRAME_HEAD_LEN offsetof(struct ccat_eth_frame, data)
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};
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@ -130,8 +130,10 @@ struct ccat_eth_register {
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* @dma: information about the associated DMA memory
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*/
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struct ccat_eth_dma_fifo {
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void (*add) (struct ccat_eth_frame *, struct ccat_eth_dma_fifo *);
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void (*add) (struct ccat_eth_dma_fifo *, struct ccat_eth_frame *);
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void __iomem *reg;
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const struct ccat_eth_frame *end;
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struct ccat_eth_frame *next;
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struct ccat_dma dma;
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};
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@ -174,7 +176,6 @@ struct ccat_info_block {
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* struct ccat_eth_priv - CCAT Ethernet/EtherCAT Master function (netdev)
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* @ccatdev: pointer to the parent struct ccat_device
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* @netdev: the net_device structure used by the kernel networking stack
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* @next_tx_frame: pointer to the next TX DMA descriptor, which the tx_thread should check for availablity
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* @info: holds a copy of the CCAT Ethernet/EtherCAT Master function information block (read from PCI config space)
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* @reg: register addresses in PCI config space of the Ethernet/EtherCAT Master function
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* @rx_fifo: DMA fifo used for RX DMA descriptors
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@ -188,7 +189,6 @@ struct ccat_info_block {
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struct ccat_eth_priv {
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const struct ccat_device *ccatdev;
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struct net_device *netdev;
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const struct ccat_eth_frame *next_tx_frame;
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struct ccat_info_block info;
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struct ccat_eth_register reg;
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struct ccat_eth_dma_fifo rx_fifo;
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@ -205,8 +205,6 @@ struct ccat_eth_priv {
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void (*kfree_skb_any) (struct sk_buff * skb);
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void (*start_queue) (struct net_device * netdev);
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void (*stop_queue) (struct net_device * netdev);
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void (*tx_fifo_full) (struct ccat_eth_priv * priv,
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const struct ccat_eth_frame * frame);
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void (*unregister) (struct net_device * netdev);
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};
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@ -19,11 +19,9 @@
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*/
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#include <linux/etherdevice.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/netdevice.h>
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#include <linux/spinlock.h>
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#include "module.h"
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#include "netdev.h"
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@ -46,6 +44,24 @@ static const u8 frameForwardEthernetFrames[] = {
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};
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#define FIFO_LENGTH 64
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#define POLL_TIME ktime_set(0, 100 * NSEC_PER_USEC)
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/**
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* Helper to check if frame in tx dma memory was already marked as sent by CCAT
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*/
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static inline bool ccat_eth_frame_sent(const struct ccat_eth_frame *const frame)
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{
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return le32_to_cpu(frame->tx_flags) & CCAT_FRAME_SENT;
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}
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/**
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* Helper to check if frame in tx dma memory was already marked as sent by CCAT
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*/
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static inline bool ccat_eth_frame_received(const struct ccat_eth_frame *const
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frame)
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{
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return le32_to_cpu(frame->rx_flags) & CCAT_FRAME_RECEIVED;
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}
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static void ecdev_kfree_skb_any(struct sk_buff *skb)
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{
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@ -75,12 +91,6 @@ static void ecdev_nop(struct net_device *const netdev)
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/* dummy called if nothing has to be done in EtherCAT operation mode */
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}
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static void ecdev_tx_fifo_full(struct ccat_eth_priv *const priv,
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const struct ccat_eth_frame *const frame)
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{
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/* we are polled -> there is nothing we can do in EtherCAT mode */
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}
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static void unregister_ecdev(struct net_device *const netdev)
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{
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struct ccat_eth_priv *const priv = netdev_priv(netdev);
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@ -88,47 +98,44 @@ static void unregister_ecdev(struct net_device *const netdev)
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ecdev_withdraw(priv->ecdev);
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}
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typedef void (*fifo_add_function) (struct ccat_eth_frame *,
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struct ccat_eth_dma_fifo *);
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static void ccat_eth_fifo_inc(struct ccat_eth_dma_fifo *fifo)
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{
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if (++fifo->next >= fifo->end)
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fifo->next = fifo->dma.virt;
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}
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static void ccat_eth_rx_fifo_add(struct ccat_eth_frame *frame,
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struct ccat_eth_dma_fifo *fifo)
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typedef void (*fifo_add_function) (struct ccat_eth_dma_fifo *,
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struct ccat_eth_frame *);
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static void ccat_eth_rx_fifo_add(struct ccat_eth_dma_fifo *fifo,
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struct ccat_eth_frame *frame)
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{
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const size_t offset = ((void *)(frame) - fifo->dma.virt);
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const u32 addr_and_length = (1 << 31) | offset;
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frame->received = 0;
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frame->rx_flags = cpu_to_le32(0);
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iowrite32(addr_and_length, fifo->reg);
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}
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static void ccat_eth_tx_fifo_add_free(struct ccat_eth_frame *frame,
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struct ccat_eth_dma_fifo *fifo)
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static void ccat_eth_tx_fifo_add_free(struct ccat_eth_dma_fifo *fifo,
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struct ccat_eth_frame *frame)
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{
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/* mark frame as ready to use for tx */
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frame->sent = 1;
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}
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static void ccat_eth_tx_fifo_full(struct ccat_eth_priv *const priv,
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const struct ccat_eth_frame *const frame)
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{
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priv->stop_queue(priv->netdev);
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priv->next_tx_frame = frame;
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frame->tx_flags = cpu_to_le32(CCAT_FRAME_SENT);
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}
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static void ccat_eth_dma_fifo_reset(struct ccat_eth_dma_fifo *fifo)
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{
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struct ccat_eth_frame *frame = fifo->dma.virt;
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const struct ccat_eth_frame *const end = frame + FIFO_LENGTH;
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/* reset hw fifo */
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iowrite32(0, fifo->reg + 0x8);
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wmb();
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if (fifo->add) {
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while (frame < end) {
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fifo->add(frame, fifo);
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++frame;
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}
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fifo->next = fifo->dma.virt;
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do {
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fifo->add(fifo, fifo->next);
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ccat_eth_fifo_inc(fifo);
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} while (fifo->next != fifo->dma.virt);
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}
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}
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@ -144,6 +151,7 @@ static int ccat_eth_dma_fifo_init(struct ccat_eth_dma_fifo *fifo,
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return -1;
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}
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fifo->add = add;
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fifo->end = ((struct ccat_eth_frame *)fifo->dma.virt) + FIFO_LENGTH;
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fifo->reg = fifo_reg;
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return 0;
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}
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@ -212,10 +220,8 @@ static void ccat_eth_priv_init_mappings(struct ccat_eth_priv *priv)
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static netdev_tx_t ccat_eth_start_xmit(struct sk_buff *skb,
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struct net_device *dev)
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{
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static size_t next = 0;
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struct ccat_eth_priv *const priv = netdev_priv(dev);
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struct ccat_eth_frame *const frame =
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((struct ccat_eth_frame *)priv->tx_fifo.dma.virt);
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struct ccat_eth_dma_fifo *const fifo = &priv->tx_fifo;
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u32 addr_and_length;
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if (skb_is_nonlinear(skb)) {
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@ -225,37 +231,40 @@ static netdev_tx_t ccat_eth_start_xmit(struct sk_buff *skb,
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return NETDEV_TX_OK;
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}
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if (skb->len > sizeof(frame->data)) {
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if (skb->len > sizeof(fifo->next->data)) {
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pr_warn("skb.len %llu exceeds dma buffer %llu -> drop frame.\n",
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(u64) skb->len, (u64) sizeof(frame->data));
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(u64) skb->len, (u64) sizeof(fifo->next->data));
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atomic64_inc(&priv->tx_dropped);
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priv->kfree_skb_any(skb);
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return NETDEV_TX_OK;
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}
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if (!frame[next].sent) {
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if (!ccat_eth_frame_sent(fifo->next)) {
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netdev_err(dev, "BUG! Tx Ring full when queue awake!\n");
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ccat_eth_tx_fifo_full(priv, &frame[next]);
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priv->stop_queue(priv->netdev);
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return NETDEV_TX_BUSY;
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}
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/* prepare frame in DMA memory */
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frame[next].sent = 0;
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frame[next].length = skb->len;
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memcpy(frame[next].data, skb->data, skb->len);
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fifo->next->tx_flags = cpu_to_le32(0);
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fifo->next->length = cpu_to_le16(skb->len);
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memcpy(fifo->next->data, skb->data, skb->len);
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/* Queue frame into CCAT TX-FIFO, CCAT ignores the first 8 bytes of the tx descriptor */
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addr_and_length = offsetof(struct ccat_eth_frame, length);
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addr_and_length += ((void*)fifo->next - fifo->dma.virt);
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addr_and_length += ((skb->len + CCAT_ETH_FRAME_HEAD_LEN) / 8) << 24;
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iowrite32(addr_and_length, priv->reg.tx_fifo);
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/* update stats */
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atomic64_add(skb->len, &priv->tx_bytes);
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priv->kfree_skb_any(skb);
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addr_and_length = 8 + (next * sizeof(*frame));
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addr_and_length +=
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((frame[next].length + CCAT_ETH_FRAME_HEAD_LEN) / 8) << 24;
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iowrite32(addr_and_length, priv->reg.tx_fifo); /* add to DMA fifo */
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atomic64_add(frame[next].length, &priv->tx_bytes); /* update stats */
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next = (next + 1) % FIFO_LENGTH;
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ccat_eth_fifo_inc(fifo);
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/* stop queue if tx ring is full */
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if (!frame[next].sent) {
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ccat_eth_tx_fifo_full(priv, &frame[next]);
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if (!ccat_eth_frame_sent(fifo->next)) {
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priv->stop_queue(priv->netdev);
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}
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return NETDEV_TX_OK;
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}
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@ -277,13 +286,11 @@ static void ccat_eth_xmit_raw(struct net_device *dev, const char *const data,
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ccat_eth_start_xmit(skb, dev);
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}
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static const size_t CCATRXDESC_HEADER_LEN = 20;
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static void ccat_eth_receive(struct net_device *const dev,
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const struct ccat_eth_frame *const frame)
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const void *const data, const size_t len)
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{
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struct sk_buff *const skb = dev_alloc_skb(len + NET_IP_ALIGN);
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struct ccat_eth_priv *const priv = netdev_priv(dev);
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const size_t len = frame->length - CCATRXDESC_HEADER_LEN;
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struct sk_buff *skb = dev_alloc_skb(len + NET_IP_ALIGN);
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if (!skb) {
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pr_info("%s() out of memory :-(\n", __FUNCTION__);
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@ -292,7 +299,7 @@ static void ccat_eth_receive(struct net_device *const dev,
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}
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skb->dev = dev;
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skb_reserve(skb, NET_IP_ALIGN);
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skb_copy_to_linear_data(skb, frame->data, len);
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skb_copy_to_linear_data(skb, data, len);
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skb_put(skb, len);
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skb->protocol = eth_type_trans(skb, dev);
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skb->ip_summed = CHECKSUM_UNNECESSARY;
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@ -300,7 +307,7 @@ static void ccat_eth_receive(struct net_device *const dev,
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netif_rx(skb);
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}
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static void ccat_eth_link_down(struct net_device *dev)
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static void ccat_eth_link_down(struct net_device *const dev)
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{
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struct ccat_eth_priv *const priv = netdev_priv(dev);
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@ -354,51 +361,39 @@ static void poll_link(struct ccat_eth_priv *const priv)
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}
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}
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/**
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* Rx handler in EtherCAT operation mode
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* priv->ecdev should always be valid!
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*/
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static void ec_poll_rx(struct net_device *dev)
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{
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static size_t next = 0;
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struct ccat_eth_priv *const priv = netdev_priv(dev);
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struct ccat_eth_frame *frame =
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((struct ccat_eth_frame *)priv->rx_fifo.dma.virt) + next;
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if (frame->received) {
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ecdev_receive(priv->ecdev, frame->data,
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frame->length - CCATRXDESC_HEADER_LEN);
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frame->received = 0;
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ccat_eth_rx_fifo_add(frame, &priv->rx_fifo);
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next = (next + 1) % FIFO_LENGTH;
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} else {
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//TODO dev_warn(&dev->dev, "%s(): frame was not ready\n", __FUNCTION__);
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}
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}
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/**
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* Poll for available rx dma descriptors in ethernet operating mode
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*/
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static void poll_rx(struct ccat_eth_priv *const priv)
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{
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struct ccat_eth_frame *const frame = priv->rx_fifo.dma.virt;
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static size_t next = 0;
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static const size_t overhead = CCAT_ETH_FRAME_HEAD_LEN - 4;
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struct ccat_eth_dma_fifo *const fifo = &priv->rx_fifo;
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/* TODO omit possible deadlock in situations with heavy traffic */
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while (frame[next].received) {
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ccat_eth_receive(priv->netdev, frame + next);
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frame[next].received = 0;
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ccat_eth_rx_fifo_add(frame + next, &priv->rx_fifo);
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next = (next + 1) % FIFO_LENGTH;
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while (ccat_eth_frame_received(fifo->next)) {
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const size_t len = le16_to_cpu(fifo->next->length) - overhead;
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if (priv->ecdev) {
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ecdev_receive(priv->ecdev, fifo->next->data, len);
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} else {
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ccat_eth_receive(priv->netdev, fifo->next->data, len);
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}
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ccat_eth_rx_fifo_add(fifo, fifo->next);
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ccat_eth_fifo_inc(fifo);
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}
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}
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static void ec_poll_rx(struct net_device *dev)
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{
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struct ccat_eth_priv *const priv = netdev_priv(dev);
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poll_rx(priv);
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}
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/**
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* Poll for available tx dma descriptors in ethernet operating mode
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*/
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static void poll_tx(struct ccat_eth_priv *const priv)
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{
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if (priv->next_tx_frame && priv->next_tx_frame->sent) {
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priv->next_tx_frame = NULL;
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if (ccat_eth_frame_sent(priv->tx_fifo.next)) {
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netif_wake_queue(priv->netdev);
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}
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}
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@ -409,14 +404,15 @@ static void poll_tx(struct ccat_eth_priv *const priv)
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*/
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static enum hrtimer_restart poll_timer_callback(struct hrtimer *timer)
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{
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struct ccat_eth_priv *priv = container_of(timer, struct ccat_eth_priv,
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poll_timer);
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struct ccat_eth_priv *const priv =
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container_of(timer, struct ccat_eth_priv, poll_timer);
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poll_link(priv);
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if(!priv->ecdev)
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if(!priv->ecdev) {
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poll_rx(priv);
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poll_tx(priv);
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hrtimer_forward_now(timer, ktime_set(0, 100 * NSEC_PER_USEC));
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poll_tx(priv);
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}
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hrtimer_forward_now(timer, POLL_TIME);
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return HRTIMER_RESTART;
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}
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@ -464,8 +460,7 @@ static int ccat_eth_open(struct net_device *dev)
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hrtimer_init(&priv->poll_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
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priv->poll_timer.function = poll_timer_callback;
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hrtimer_start(&priv->poll_timer, ktime_set(0, 100000),
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HRTIMER_MODE_REL);
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hrtimer_start(&priv->poll_timer, POLL_TIME, HRTIMER_MODE_REL);
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return 0;
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}
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@ -475,7 +470,6 @@ static int ccat_eth_stop(struct net_device *dev)
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priv->stop_queue(dev);
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hrtimer_cancel(&priv->poll_timer);
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netdev_info(dev, "stopped.\n");
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return 0;
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}
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@ -519,7 +513,6 @@ struct ccat_eth_priv *ccat_eth_init(const struct ccat_device *const ccatdev,
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priv->kfree_skb_any = ecdev_kfree_skb_any;
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priv->start_queue = ecdev_nop;
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priv->stop_queue = ecdev_nop;
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priv->tx_fifo_full = ecdev_tx_fifo_full;
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priv->unregister = unregister_ecdev;
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priv->carrier_off(netdev);
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@ -540,7 +533,6 @@ struct ccat_eth_priv *ccat_eth_init(const struct ccat_device *const ccatdev,
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priv->kfree_skb_any = dev_kfree_skb_any;
|
||||
priv->start_queue = netif_start_queue;
|
||||
priv->stop_queue = netif_stop_queue;
|
||||
priv->tx_fifo_full = ccat_eth_tx_fifo_full;
|
||||
priv->unregister = unregister_netdev;
|
||||
|
||||
priv->carrier_off(netdev);
|
||||
|
|
@ -559,5 +551,4 @@ void ccat_eth_remove(struct ccat_eth_priv *const priv)
|
|||
priv->unregister(priv->netdev);
|
||||
ccat_eth_priv_free_dma(priv);
|
||||
free_netdev(priv->netdev);
|
||||
pr_debug("%s(): done\n", __FUNCTION__);
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in New Issue