sfc: Use TX PIO for sufficiently small packets
Sufficiently small linear packets can be copied into the PIO buffer
with a single call to memcpy_toio(). Non-linear packets require an
intermediate cache-line-sized buffer.
[bwh: I wrote the first version of this, but Jon did the hard work to
handle non-linear packets.]
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index 6febecc..aac22a1 100644
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -212,6 +212,7 @@
* blocks
* @tso_packets: Number of packets via the TSO xmit path
* @pushes: Number of times the TX push feature has been used
+ * @pio_packets: Number of times the TX PIO feature has been used
* @empty_read_count: If the completion path has seen the queue as empty
* and the transmission path has not yet checked this, the value of
* @read_count bitwise-added to %EFX_EMPTY_COUNT_VALID; otherwise 0.
@@ -243,6 +244,7 @@
unsigned int tso_long_headers;
unsigned int tso_packets;
unsigned int pushes;
+ unsigned int pio_packets;
/* Members shared between paths and sometimes updated */
unsigned int empty_read_count ____cacheline_aligned_in_smp;