sfc: Make the dmaq size a run-time setting (rather than compile-time)

- Allow the ring size to be specified in non
   power-of-two sizes (for instance to limit
   the amount of receive buffers).
 - Automatically size the event queue.

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

1 files changed, 10 insertions, 3 deletions

diff --git a/drivers/net/sfc/net_driver.h b/drivers/net/sfc/net_driver.h
index cfc65f5a3c09..ac622ab72e11 100644
--- a/drivers/net/sfc/net_driver.h
+++ b/drivers/net/sfc/net_driver.h
@@ -137,6 +137,7 @@ struct efx_tx_buffer {
  * @channel: The associated channel
  * @buffer: The software buffer ring
  * @txd: The hardware descriptor ring
+ * @ptr_mask: The size of the ring minus 1.
  * @flushed: Used when handling queue flushing
  * @read_count: Current read pointer.
  *      This is the number of buffers that have been removed from both rings.
@@ -170,6 +171,7 @@ struct efx_tx_queue {
         struct efx_nic *nic;
         struct efx_tx_buffer *buffer;
         struct efx_special_buffer txd;
+        unsigned int ptr_mask;
         enum efx_flush_state flushed;
 
         /* Members used mainly on the completion path */
@@ -227,6 +229,7 @@ struct efx_rx_page_state {
  * @efx: The associated Efx NIC
  * @buffer: The software buffer ring
  * @rxd: The hardware descriptor ring
+ * @ptr_mask: The size of the ring minus 1.
  * @added_count: Number of buffers added to the receive queue.
  * @notified_count: Number of buffers given to NIC (<= @added_count).
  * @removed_count: Number of buffers removed from the receive queue.
@@ -238,9 +241,6 @@ struct efx_rx_page_state {
  * @min_fill: RX descriptor minimum non-zero fill level.
  *      This records the minimum fill level observed when a ring
  *      refill was triggered.
- * @min_overfill: RX descriptor minimum overflow fill level.
- *      This records the minimum fill level at which RX queue
- *      overflow was observed.  It should never be set.
  * @alloc_page_count: RX allocation strategy counter.
  * @alloc_skb_count: RX allocation strategy counter.
  * @slow_fill: Timer used to defer efx_nic_generate_fill_event().
@@ -250,6 +250,7 @@ struct efx_rx_queue {
         struct efx_nic *efx;
         struct efx_rx_buffer *buffer;
         struct efx_special_buffer rxd;
+        unsigned int ptr_mask;
 
         int added_count;
         int notified_count;
@@ -307,6 +308,7 @@ enum efx_rx_alloc_method {
  * @reset_work: Scheduled reset work thread
  * @work_pending: Is work pending via NAPI?
  * @eventq: Event queue buffer
+ * @eventq_mask: Event queue pointer mask
  * @eventq_read_ptr: Event queue read pointer
  * @last_eventq_read_ptr: Last event queue read pointer value.
  * @magic_count: Event queue test event count
@@ -339,6 +341,7 @@ struct efx_channel {
         struct napi_struct napi_str;
         bool work_pending;
         struct efx_special_buffer eventq;
+        unsigned int eventq_mask;
         unsigned int eventq_read_ptr;
         unsigned int last_eventq_read_ptr;
         unsigned int magic_count;
@@ -641,6 +644,8 @@ union efx_multicast_hash {
  * @tx_queue: TX DMA queues
  * @rx_queue: RX DMA queues
  * @channel: Channels
+ * @rxq_entries: Size of receive queues requested by user.
+ * @txq_entries: Size of transmit queues requested by user.
  * @next_buffer_table: First available buffer table id
  * @n_channels: Number of channels in use
  * @n_rx_channels: Number of channels used for RX (= number of RX queues)
@@ -726,6 +731,8 @@ struct efx_nic {
 
         struct efx_channel *channel[EFX_MAX_CHANNELS];
 
+        unsigned rxq_entries;
+        unsigned txq_entries;
         unsigned next_buffer_table;
         unsigned n_channels;
         unsigned n_rx_channels;