sfc: Refactor channel and queue lookup and iteration

In preparation for changes to the way channels and queue structures
are allocated, revise the macros and functions used to look up and
iterator over them.

- Replace efx_for_each_tx_queue() with iteration over channels then TX
  queues
- Replace efx_for_each_rx_queue() with iteration over channels then RX
  queues (with one exception, shortly to be removed)
- Introduce efx_get_{channel,rx_queue,tx_queue}() functions to look up
  channels and queues by index
- Introduce efx_channel_get_{rx,tx}_queue() functions to look up a
  channel's queues

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 37 insertions, 6 deletions

diff --git a/drivers/net/sfc/net_driver.h b/drivers/net/sfc/net_driver.h
index 89c6e02c57d..eb3537529c9 100644
--- a/drivers/net/sfc/net_driver.h
+++ b/drivers/net/sfc/net_driver.h
@@ -909,18 +909,34 @@ struct efx_nic_type {
  *
  *************************************************************************/
 
+static inline struct efx_channel *
+efx_get_channel(struct efx_nic *efx, unsigned index)
+{
+	EFX_BUG_ON_PARANOID(index >= efx->n_channels);
+	return &efx->channel[index];
+}
+
 /* Iterate over all used channels */
 #define efx_for_each_channel(_channel, _efx)				\
 	for (_channel = &((_efx)->channel[0]);				\
 	     _channel < &((_efx)->channel[(efx)->n_channels]);		\
 	     _channel++)
 
-/* Iterate over all used TX queues */
-#define efx_for_each_tx_queue(_tx_queue, _efx)				\
-	for (_tx_queue = &((_efx)->tx_queue[0]);			\
-	     _tx_queue < &((_efx)->tx_queue[EFX_TXQ_TYPES *		\
-					    (_efx)->n_tx_channels]);	\
-	     _tx_queue++)
+static inline struct efx_tx_queue *
+efx_get_tx_queue(struct efx_nic *efx, unsigned index, unsigned type)
+{
+	EFX_BUG_ON_PARANOID(index >= efx->n_tx_channels ||
+			    type >= EFX_TXQ_TYPES);
+	return &efx->tx_queue[index * EFX_TXQ_TYPES + type];
+}
+
+static inline struct efx_tx_queue *
+efx_channel_get_tx_queue(struct efx_channel *channel, unsigned type)
+{
+	struct efx_tx_queue *tx_queue = channel->tx_queue;
+	EFX_BUG_ON_PARANOID(type >= EFX_TXQ_TYPES);
+	return tx_queue ? tx_queue + type : NULL;
+}
 
 /* Iterate over all TX queues belonging to a channel */
 #define efx_for_each_channel_tx_queue(_tx_queue, _channel)		\
@@ -928,12 +944,27 @@ struct efx_nic_type {
 	     _tx_queue && _tx_queue < (_channel)->tx_queue + EFX_TXQ_TYPES; \
 	     _tx_queue++)
 
+static inline struct efx_rx_queue *
+efx_get_rx_queue(struct efx_nic *efx, unsigned index)
+{
+	EFX_BUG_ON_PARANOID(index >= efx->n_rx_channels);
+	return &efx->rx_queue[index];
+}
+
 /* Iterate over all used RX queues */
 #define efx_for_each_rx_queue(_rx_queue, _efx)				\
 	for (_rx_queue = &((_efx)->rx_queue[0]);			\
 	     _rx_queue < &((_efx)->rx_queue[(_efx)->n_rx_channels]);	\
 	     _rx_queue++)
 
+static inline struct efx_rx_queue *
+efx_channel_get_rx_queue(struct efx_channel *channel)
+{
+	struct efx_rx_queue *rx_queue =
+		&channel->efx->rx_queue[channel->channel];
+	return rx_queue->channel == channel ? rx_queue : NULL;
+}
+
 /* Iterate over all RX queues belonging to a channel */
 #define efx_for_each_channel_rx_queue(_rx_queue, _channel)		\
 	for (_rx_queue = &((_channel)->efx->rx_queue[(_channel)->channel]); \