diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/can/c_can/c_can.c | 127 | ||||
| -rw-r--r-- | drivers/net/can/c_can/c_can.h | 8 |
2 files changed, 43 insertions, 92 deletions
diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c index 61fde414bb1f..99d36bf1ba21 100644 --- a/drivers/net/can/c_can/c_can.c +++ b/drivers/net/can/c_can/c_can.c @@ -237,24 +237,6 @@ static inline void c_can_reset_ram(const struct c_can_priv *priv, bool enable) priv->raminit(priv, enable); } -static inline int get_tx_next_msg_obj(const struct c_can_priv *priv) -{ - return (priv->tx_next & C_CAN_NEXT_MSG_OBJ_MASK) + - C_CAN_MSG_OBJ_TX_FIRST; -} - -static inline int get_tx_echo_msg_obj(int txecho) -{ - return (txecho & C_CAN_NEXT_MSG_OBJ_MASK) + C_CAN_MSG_OBJ_TX_FIRST; -} - -static u32 c_can_read_reg32(struct c_can_priv *priv, enum reg index) -{ - u32 val = priv->read_reg(priv, index); - val |= ((u32) priv->read_reg(priv, index + 1)) << 16; - return val; -} - static void c_can_irq_control(struct c_can_priv *priv, bool enable) { u32 ctrl = priv->read_reg(priv, C_CAN_CTRL_REG) & ~CONTROL_IRQMSK; @@ -294,8 +276,8 @@ static inline void c_can_object_put(struct net_device *dev, int iface, c_can_obj_update(dev, iface, cmd | IF_COMM_WR, obj); } -static void c_can_write_msg_object(struct net_device *dev, int iface, - struct can_frame *frame, int obj) +static void c_can_setup_tx_object(struct net_device *dev, int iface, + struct can_frame *frame, int obj) { struct c_can_priv *priv = netdev_priv(dev); u16 ctrl = IF_MCONT_TX | frame->can_dlc; @@ -321,8 +303,6 @@ static void c_can_write_msg_object(struct net_device *dev, int iface, priv->write_reg(priv, C_CAN_IFACE(DATA1_REG, iface) + i / 2, frame->data[i] | (frame->data[i + 1] << 8)); } - - c_can_object_put(dev, iface, obj, IF_COMM_TX); } static inline void c_can_activate_all_lower_rx_msg_obj(struct net_device *dev, @@ -432,47 +412,38 @@ static void c_can_inval_msg_object(struct net_device *dev, int iface, int obj) c_can_object_put(dev, iface, obj, IF_COMM_INVAL); } -static inline int c_can_is_next_tx_obj_busy(struct c_can_priv *priv, int objno) -{ - int val = c_can_read_reg32(priv, C_CAN_TXRQST1_REG); - - /* - * as transmission request register's bit n-1 corresponds to - * message object n, we need to handle the same properly. - */ - if (val & (1 << (objno - 1))) - return 1; - - return 0; -} - static netdev_tx_t c_can_start_xmit(struct sk_buff *skb, - struct net_device *dev) + struct net_device *dev) { - u32 msg_obj_no; - struct c_can_priv *priv = netdev_priv(dev); struct can_frame *frame = (struct can_frame *)skb->data; + struct c_can_priv *priv = netdev_priv(dev); + u32 idx, obj; if (can_dropped_invalid_skb(dev, skb)) return NETDEV_TX_OK; - - spin_lock_bh(&priv->xmit_lock); - msg_obj_no = get_tx_next_msg_obj(priv); - - /* prepare message object for transmission */ - c_can_write_msg_object(dev, IF_TX, frame, msg_obj_no); - priv->dlc[msg_obj_no - C_CAN_MSG_OBJ_TX_FIRST] = frame->can_dlc; - can_put_echo_skb(skb, dev, msg_obj_no - C_CAN_MSG_OBJ_TX_FIRST); - /* - * we have to stop the queue in case of a wrap around or - * if the next TX message object is still in use + * This is not a FIFO. C/D_CAN sends out the buffers + * prioritized. The lowest buffer number wins. */ - priv->tx_next++; - if (c_can_is_next_tx_obj_busy(priv, get_tx_next_msg_obj(priv)) || - (priv->tx_next & C_CAN_NEXT_MSG_OBJ_MASK) == 0) + idx = fls(atomic_read(&priv->tx_active)); + obj = idx + C_CAN_MSG_OBJ_TX_FIRST; + + /* If this is the last buffer, stop the xmit queue */ + if (idx == C_CAN_MSG_OBJ_TX_NUM - 1) netif_stop_queue(dev); - spin_unlock_bh(&priv->xmit_lock); + /* + * Store the message in the interface so we can call + * can_put_echo_skb(). We must do this before we enable + * transmit as we might race against do_tx(). + */ + c_can_setup_tx_object(dev, IF_TX, frame, obj); + priv->dlc[idx] = frame->can_dlc; + can_put_echo_skb(skb, dev, idx); + + /* Update the active bits */ + atomic_add((1 << idx), &priv->tx_active); + /* Start transmission */ + c_can_object_put(dev, IF_TX, obj, IF_COMM_TX); return NETDEV_TX_OK; } @@ -589,6 +560,10 @@ static int c_can_chip_config(struct net_device *dev) /* set a `lec` value so that we can check for updates later */ priv->write_reg(priv, C_CAN_STS_REG, LEC_UNUSED); + /* Clear all internal status */ + atomic_set(&priv->tx_active, 0); + priv->rxmasked = 0; + /* set bittiming params */ return c_can_set_bittiming(dev); } @@ -609,10 +584,6 @@ static int c_can_start(struct net_device *dev) priv->can.state = CAN_STATE_ERROR_ACTIVE; - /* reset tx helper pointers and the rx mask */ - priv->tx_next = priv->tx_echo = 0; - priv->rxmasked = 0; - return 0; } @@ -671,42 +642,29 @@ static int c_can_get_berr_counter(const struct net_device *dev, return err; } -/* - * priv->tx_echo holds the number of the oldest can_frame put for - * transmission into the hardware, but not yet ACKed by the CAN tx - * complete IRQ. - * - * We iterate from priv->tx_echo to priv->tx_next and check if the - * packet has been transmitted, echo it back to the CAN framework. - * If we discover a not yet transmitted packet, stop looking for more. - */ static void c_can_do_tx(struct net_device *dev) { struct c_can_priv *priv = netdev_priv(dev); struct net_device_stats *stats = &dev->stats; - u32 val, obj, pkts = 0, bytes = 0; + u32 idx, obj, pkts = 0, bytes = 0, pend, clr; - spin_lock_bh(&priv->xmit_lock); + clr = pend = priv->read_reg(priv, C_CAN_INTPND2_REG); - for (; (priv->tx_next - priv->tx_echo) > 0; priv->tx_echo++) { - obj = get_tx_echo_msg_obj(priv->tx_echo); - val = c_can_read_reg32(priv, C_CAN_TXRQST1_REG); - - if (val & (1 << (obj - 1))) - break; - - can_get_echo_skb(dev, obj - C_CAN_MSG_OBJ_TX_FIRST); - bytes += priv->dlc[obj - C_CAN_MSG_OBJ_TX_FIRST]; + while ((idx = ffs(pend))) { + idx--; + pend &= ~(1 << idx); + obj = idx + C_CAN_MSG_OBJ_TX_FIRST; + c_can_inval_msg_object(dev, IF_RX, obj); + can_get_echo_skb(dev, idx); + bytes += priv->dlc[idx]; pkts++; - c_can_inval_msg_object(dev, IF_TX, obj); } - /* restart queue if wrap-up or if queue stalled on last pkt */ - if (((priv->tx_next & C_CAN_NEXT_MSG_OBJ_MASK) != 0) || - ((priv->tx_echo & C_CAN_NEXT_MSG_OBJ_MASK) == 0)) - netif_wake_queue(dev); + /* Clear the bits in the tx_active mask */ + atomic_sub(clr, &priv->tx_active); - spin_unlock_bh(&priv->xmit_lock); + if (clr & (1 << (C_CAN_MSG_OBJ_TX_NUM - 1))) + netif_wake_queue(dev); if (pkts) { stats->tx_bytes += bytes; @@ -1192,7 +1150,6 @@ struct net_device *alloc_c_can_dev(void) return NULL; priv = netdev_priv(dev); - spin_lock_init(&priv->xmit_lock); netif_napi_add(dev, &priv->napi, c_can_poll, C_CAN_NAPI_WEIGHT); priv->dev = dev; diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h index d9f59cc4fcb5..a5f10a01e49f 100644 --- a/drivers/net/can/c_can/c_can.h +++ b/drivers/net/can/c_can/c_can.h @@ -37,8 +37,6 @@ #define C_CAN_MSG_OBJ_RX_SPLIT 9 #define C_CAN_MSG_RX_LOW_LAST (C_CAN_MSG_OBJ_RX_SPLIT - 1) - -#define C_CAN_NEXT_MSG_OBJ_MASK (C_CAN_MSG_OBJ_TX_NUM - 1) #define RECEIVE_OBJECT_BITS 0x0000ffff enum reg { @@ -175,16 +173,12 @@ struct c_can_priv { struct napi_struct napi; struct net_device *dev; struct device *device; - spinlock_t xmit_lock; - int tx_object; + atomic_t tx_active; int last_status; u16 (*read_reg) (struct c_can_priv *priv, enum reg index); void (*write_reg) (struct c_can_priv *priv, enum reg index, u16 val); void __iomem *base; const u16 *regs; - unsigned long irq_flags; /* for request_irq() */ - unsigned int tx_next; - unsigned int tx_echo; void *priv; /* for board-specific data */ enum c_can_dev_id type; u32 __iomem *raminit_ctrlreg; |
