sfc: Allow shared pages to be recycled

Insert a structure at the start of the shared page that
tracks the dma mapping refcnt. DMA into the next cache
line of the (shared) page (plus EFX_PAGE_IP_ALIGN).

When recycling a page, check the page refcnt. If the
page is otherwise unused, then resurrect the other
receive buffer that previously referenced the page.
Be careful not to overflow the receive ring, since we
can now resurrect n receive buffers in a row.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Steve Hodgson
2010-06-01 11:20:53 +00:00
committed by David S. Miller
parent 244558006c
commit 62b330baed
3 changed files with 62 additions and 43 deletions

View File

@@ -469,7 +469,8 @@ static void efx_init_channels(struct efx_nic *efx)
efx->rx_buffer_len = (max(EFX_PAGE_IP_ALIGN, NET_IP_ALIGN) +
EFX_MAX_FRAME_LEN(efx->net_dev->mtu) +
efx->type->rx_buffer_padding);
efx->rx_buffer_order = get_order(efx->rx_buffer_len);
efx->rx_buffer_order = get_order(efx->rx_buffer_len +
sizeof(struct efx_rx_page_state));
/* Initialise the channels */
efx_for_each_channel(channel, efx) {