i40e/i40evf: Add support for padding start of frames
This patch adds padding to the start of frames to make room for headroom
for us to eventually start using build_skb. Right now we guarantee at
least NET_SKB_PAD + NET_IP_ALIGN, however we allocate more space if more is
available. For example on x86 the headroom should be 192 bytes.
On systems that have too large of a cache line size to support storing 1.5K
padding and shared info we default to using 3K buffers and reserve
everything that isn't used for skb_shared_info or the data buffer for
headroom.
Change-ID: I33c641c9a1ea10cf7cc484c2d20985368d2d709a
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 97489d6..b6ec9be 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -3038,6 +3038,12 @@
return -ENOMEM;
}
+ /* configure Rx buffer alignment */
+ if (!vsi->netdev || (vsi->back->flags & I40E_FLAG_LEGACY_RX))
+ clear_ring_build_skb_enabled(ring);
+ else
+ set_ring_build_skb_enabled(ring);
+
/* cache tail for quicker writes, and clear the reg before use */
ring->tail = hw->hw_addr + I40E_QRX_TAIL(pf_q);
writel(0, ring->tail);
@@ -3079,7 +3085,8 @@
vsi->max_frame = I40E_MAX_RXBUFFER;
vsi->rx_buf_len = I40E_RXBUFFER_2048;
#if (PAGE_SIZE < 8192)
- } else if (vsi->netdev->mtu <= ETH_DATA_LEN) {
+ } else if (!I40E_2K_TOO_SMALL_WITH_PADDING &&
+ (vsi->netdev->mtu <= ETH_DATA_LEN)) {
vsi->max_frame = I40E_RXBUFFER_1536 - NET_IP_ALIGN;
vsi->rx_buf_len = I40E_RXBUFFER_1536 - NET_IP_ALIGN;
#endif