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>
diff --git a/drivers/net/sfc/tx.c b/drivers/net/sfc/tx.c
index 6a6acc4..1172698 100644
--- a/drivers/net/sfc/tx.c
+++ b/drivers/net/sfc/tx.c
@@ -28,7 +28,7 @@
* The tx_queue descriptor ring fill-level must fall below this value
* before we restart the netif queue
*/
-#define EFX_TXQ_THRESHOLD (EFX_TXQ_MASK / 2u)
+#define EFX_TXQ_THRESHOLD(_efx) ((_efx)->txq_entries / 2u)
/* We need to be able to nest calls to netif_tx_stop_queue(), partly
* because of the 2 hardware queues associated with each core queue,
@@ -207,7 +207,7 @@
}
fill_level = tx_queue->insert_count - tx_queue->old_read_count;
- q_space = EFX_TXQ_MASK - 1 - fill_level;
+ q_space = efx->txq_entries - 1 - fill_level;
/* Map for DMA. Use pci_map_single rather than pci_map_page
* since this is more efficient on machines with sparse
@@ -244,14 +244,14 @@
&tx_queue->read_count;
fill_level = (tx_queue->insert_count
- tx_queue->old_read_count);
- q_space = EFX_TXQ_MASK - 1 - fill_level;
+ q_space = efx->txq_entries - 1 - fill_level;
if (unlikely(q_space-- <= 0))
goto stop;
smp_mb();
--tx_queue->stopped;
}
- insert_ptr = tx_queue->insert_count & EFX_TXQ_MASK;
+ insert_ptr = tx_queue->insert_count & tx_queue->ptr_mask;
buffer = &tx_queue->buffer[insert_ptr];
efx_tsoh_free(tx_queue, buffer);
EFX_BUG_ON_PARANOID(buffer->tsoh);
@@ -320,7 +320,7 @@
/* Work backwards until we hit the original insert pointer value */
while (tx_queue->insert_count != tx_queue->write_count) {
--tx_queue->insert_count;
- insert_ptr = tx_queue->insert_count & EFX_TXQ_MASK;
+ insert_ptr = tx_queue->insert_count & tx_queue->ptr_mask;
buffer = &tx_queue->buffer[insert_ptr];
efx_dequeue_buffer(tx_queue, buffer);
buffer->len = 0;
@@ -350,8 +350,8 @@
struct efx_nic *efx = tx_queue->efx;
unsigned int stop_index, read_ptr;
- stop_index = (index + 1) & EFX_TXQ_MASK;
- read_ptr = tx_queue->read_count & EFX_TXQ_MASK;
+ stop_index = (index + 1) & tx_queue->ptr_mask;
+ read_ptr = tx_queue->read_count & tx_queue->ptr_mask;
while (read_ptr != stop_index) {
struct efx_tx_buffer *buffer = &tx_queue->buffer[read_ptr];
@@ -368,7 +368,7 @@
buffer->len = 0;
++tx_queue->read_count;
- read_ptr = tx_queue->read_count & EFX_TXQ_MASK;
+ read_ptr = tx_queue->read_count & tx_queue->ptr_mask;
}
}
@@ -402,7 +402,7 @@
unsigned fill_level;
struct efx_nic *efx = tx_queue->efx;
- EFX_BUG_ON_PARANOID(index > EFX_TXQ_MASK);
+ EFX_BUG_ON_PARANOID(index > tx_queue->ptr_mask);
efx_dequeue_buffers(tx_queue, index);
@@ -412,7 +412,7 @@
smp_mb();
if (unlikely(tx_queue->stopped) && likely(efx->port_enabled)) {
fill_level = tx_queue->insert_count - tx_queue->read_count;
- if (fill_level < EFX_TXQ_THRESHOLD) {
+ if (fill_level < EFX_TXQ_THRESHOLD(efx)) {
EFX_BUG_ON_PARANOID(!efx_dev_registered(efx));
/* Do this under netif_tx_lock(), to avoid racing
@@ -430,18 +430,24 @@
int efx_probe_tx_queue(struct efx_tx_queue *tx_queue)
{
struct efx_nic *efx = tx_queue->efx;
- unsigned int txq_size;
+ unsigned int entries;
int i, rc;
- netif_dbg(efx, probe, efx->net_dev, "creating TX queue %d\n",
- tx_queue->queue);
+ /* Create the smallest power-of-two aligned ring */
+ entries = max(roundup_pow_of_two(efx->txq_entries), EFX_MIN_DMAQ_SIZE);
+ EFX_BUG_ON_PARANOID(entries > EFX_MAX_DMAQ_SIZE);
+ tx_queue->ptr_mask = entries - 1;
+
+ netif_dbg(efx, probe, efx->net_dev,
+ "creating TX queue %d size %#x mask %#x\n",
+ tx_queue->queue, efx->txq_entries, tx_queue->ptr_mask);
/* Allocate software ring */
- txq_size = EFX_TXQ_SIZE * sizeof(*tx_queue->buffer);
- tx_queue->buffer = kzalloc(txq_size, GFP_KERNEL);
+ tx_queue->buffer = kzalloc(entries * sizeof(*tx_queue->buffer),
+ GFP_KERNEL);
if (!tx_queue->buffer)
return -ENOMEM;
- for (i = 0; i <= EFX_TXQ_MASK; ++i)
+ for (i = 0; i <= tx_queue->ptr_mask; ++i)
tx_queue->buffer[i].continuation = true;
/* Allocate hardware ring */
@@ -481,7 +487,7 @@
/* Free any buffers left in the ring */
while (tx_queue->read_count != tx_queue->write_count) {
- buffer = &tx_queue->buffer[tx_queue->read_count & EFX_TXQ_MASK];
+ buffer = &tx_queue->buffer[tx_queue->read_count & tx_queue->ptr_mask];
efx_dequeue_buffer(tx_queue, buffer);
buffer->continuation = true;
buffer->len = 0;
@@ -741,7 +747,7 @@
fill_level = tx_queue->insert_count - tx_queue->old_read_count;
/* -1 as there is no way to represent all descriptors used */
- q_space = EFX_TXQ_MASK - 1 - fill_level;
+ q_space = efx->txq_entries - 1 - fill_level;
while (1) {
if (unlikely(q_space-- <= 0)) {
@@ -757,7 +763,7 @@
*(volatile unsigned *)&tx_queue->read_count;
fill_level = (tx_queue->insert_count
- tx_queue->old_read_count);
- q_space = EFX_TXQ_MASK - 1 - fill_level;
+ q_space = efx->txq_entries - 1 - fill_level;
if (unlikely(q_space-- <= 0)) {
*final_buffer = NULL;
return 1;
@@ -766,13 +772,13 @@
--tx_queue->stopped;
}
- insert_ptr = tx_queue->insert_count & EFX_TXQ_MASK;
+ insert_ptr = tx_queue->insert_count & tx_queue->ptr_mask;
buffer = &tx_queue->buffer[insert_ptr];
++tx_queue->insert_count;
EFX_BUG_ON_PARANOID(tx_queue->insert_count -
- tx_queue->read_count >
- EFX_TXQ_MASK);
+ tx_queue->read_count >=
+ efx->txq_entries);
efx_tsoh_free(tx_queue, buffer);
EFX_BUG_ON_PARANOID(buffer->len);
@@ -813,7 +819,7 @@
{
struct efx_tx_buffer *buffer;
- buffer = &tx_queue->buffer[tx_queue->insert_count & EFX_TXQ_MASK];
+ buffer = &tx_queue->buffer[tx_queue->insert_count & tx_queue->ptr_mask];
efx_tsoh_free(tx_queue, buffer);
EFX_BUG_ON_PARANOID(buffer->len);
EFX_BUG_ON_PARANOID(buffer->unmap_len);
@@ -838,7 +844,7 @@
while (tx_queue->insert_count != tx_queue->write_count) {
--tx_queue->insert_count;
buffer = &tx_queue->buffer[tx_queue->insert_count &
- EFX_TXQ_MASK];
+ tx_queue->ptr_mask];
efx_tsoh_free(tx_queue, buffer);
EFX_BUG_ON_PARANOID(buffer->skb);
if (buffer->unmap_len) {
@@ -1168,7 +1174,7 @@
unsigned i;
if (tx_queue->buffer) {
- for (i = 0; i <= EFX_TXQ_MASK; ++i)
+ for (i = 0; i <= tx_queue->ptr_mask; ++i)
efx_tsoh_free(tx_queue, &tx_queue->buffer[i]);
}