e1000: Buffer optimizations for small MTU
Remove multi-descriptor support from legacy recieve path
Add memory usage efficiency by using more correct size descriptors for
small MTU sizes and optimize using LPE for <= 1522 byte frame sizes
An extra performance fix that effected our TCP window size growth
as a receiver. Set our initial buffer to be 128 bytes instead of 256
to prevent over-socket charge when truesize is computed in the stack.
old way: truesize = 256 + l1 = 256 + 1460 = 1716
new way: truesize = 128 + l1 = 128 + 1460 = 1588
The magic value that we can't cross is 1648.
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: John Ronciak <john.ronciak@intel.com>
diff --git a/drivers/net/e1000/e1000.h b/drivers/net/e1000/e1000.h
index 764808f..2dfabdb 100644
--- a/drivers/net/e1000/e1000.h
+++ b/drivers/net/e1000/e1000.h
@@ -114,6 +114,8 @@
/* Supported Rx Buffer Sizes */
#define E1000_RXBUFFER_128 128 /* Used for packet split */
#define E1000_RXBUFFER_256 256 /* Used for packet split */
+#define E1000_RXBUFFER_512 512
+#define E1000_RXBUFFER_1024 1024
#define E1000_RXBUFFER_2048 2048
#define E1000_RXBUFFER_4096 4096
#define E1000_RXBUFFER_8192 8192