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Commit 4afb7527 authored by stephen hemminger's avatar stephen hemminger Committed by David S. Miller
Browse files

sfc: convert references to LRO to GRO 



This driver now uses Generic Receive Offload, not the older LRO.
Change references to LRO in names and comments.

Signed-off-by: default avatarStephen Hemminger <shemminger@vyatta.com>
Acked-by: default avatarBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 376d940e

drivers/net/sfc/rx.c

+15 −15
Original line number Diff line number Diff line
@@ -37,7 +37,7 @@ 
 * This driver supports two methods for allocating and using RX buffers:

 * each RX buffer may be backed by an skb or by an order-n page.

 *

 * When LRO is in use then the second method has a lower overhead,

 * When GRO is in use then the second method has a lower overhead,

 * since we don't have to allocate then free skbs on reassembled frames.

 *

 * Values:
@@ -50,25 +50,25 @@ 
 *

 *   - Since pushing and popping descriptors are separated by the rx_queue

 *     size, so the watermarks should be ~rxd_size.

 *   - The performance win by using page-based allocation for LRO is less

 *     than the performance hit of using page-based allocation of non-LRO,

 *   - The performance win by using page-based allocation for GRO is less

 *     than the performance hit of using page-based allocation of non-GRO,

 *     so the watermarks should reflect this.

 *

 * Per channel we maintain a single variable, updated by each channel:

 *

 *   rx_alloc_level += (lro_performed ? RX_ALLOC_FACTOR_LRO :

 *   rx_alloc_level += (gro_performed ? RX_ALLOC_FACTOR_GRO :

 *                      RX_ALLOC_FACTOR_SKB)

 * Per NAPI poll interval, we constrain rx_alloc_level to 0..MAX (which

 * limits the hysteresis), and update the allocation strategy:

 *

 *   rx_alloc_method = (rx_alloc_level > RX_ALLOC_LEVEL_LRO ?

 *   rx_alloc_method = (rx_alloc_level > RX_ALLOC_LEVEL_GRO ?

 *                      RX_ALLOC_METHOD_PAGE : RX_ALLOC_METHOD_SKB)

 */

static int rx_alloc_method = RX_ALLOC_METHOD_AUTO;



#define RX_ALLOC_LEVEL_LRO 0x2000

#define RX_ALLOC_LEVEL_GRO 0x2000

#define RX_ALLOC_LEVEL_MAX 0x3000

#define RX_ALLOC_FACTOR_LRO 1

#define RX_ALLOC_FACTOR_GRO 1

#define RX_ALLOC_FACTOR_SKB (-2)



/* This is the percentage fill level below which new RX descriptors
@@ -441,19 +441,19 @@ static void efx_rx_packet__check_len(struct efx_rx_queue *rx_queue, 
	efx_rx_queue_channel(rx_queue)->n_rx_overlength++;

}



/* Pass a received packet up through the generic LRO stack

/* Pass a received packet up through the generic GRO stack

 *

 * Handles driverlink veto, and passes the fragment up via

 * the appropriate LRO method

 * the appropriate GRO method

 */

static void efx_rx_packet_lro(struct efx_channel *channel,

static void efx_rx_packet_gro(struct efx_channel *channel,

			      struct efx_rx_buffer *rx_buf,

			      bool checksummed)

{

	struct napi_struct *napi = &channel->napi_str;

	gro_result_t gro_result;



	/* Pass the skb/page into the LRO engine */

	/* Pass the skb/page into the GRO engine */

	if (rx_buf->page) {

		struct efx_nic *efx = channel->efx;

		struct page *page = rx_buf->page;
@@ -499,7 +499,7 @@ static void efx_rx_packet_lro(struct efx_channel *channel, 
	if (gro_result == GRO_NORMAL) {

		channel->rx_alloc_level += RX_ALLOC_FACTOR_SKB;

	} else if (gro_result != GRO_DROP) {

		channel->rx_alloc_level += RX_ALLOC_FACTOR_LRO;

		channel->rx_alloc_level += RX_ALLOC_FACTOR_GRO;

		channel->irq_mod_score += 2;

	}

}
@@ -605,7 +605,7 @@ void __efx_rx_packet(struct efx_channel *channel, 
	}



	if (likely(checksummed || rx_buf->page)) {

		efx_rx_packet_lro(channel, rx_buf, checksummed);

		efx_rx_packet_gro(channel, rx_buf, checksummed);

		return;

	}
@@ -628,7 +628,7 @@ void efx_rx_strategy(struct efx_channel *channel) 
{

	enum efx_rx_alloc_method method = rx_alloc_method;



	/* Only makes sense to use page based allocation if LRO is enabled */

	/* Only makes sense to use page based allocation if GRO is enabled */

	if (!(channel->efx->net_dev->features & NETIF_F_GRO)) {

		method = RX_ALLOC_METHOD_SKB;

	} else if (method == RX_ALLOC_METHOD_AUTO) {
@@ -639,7 +639,7 @@ void efx_rx_strategy(struct efx_channel *channel) 
			channel->rx_alloc_level = RX_ALLOC_LEVEL_MAX;



		/* Decide on the allocation method */

		method = ((channel->rx_alloc_level > RX_ALLOC_LEVEL_LRO) ?

		method = ((channel->rx_alloc_level > RX_ALLOC_LEVEL_GRO) ?

			  RX_ALLOC_METHOD_PAGE : RX_ALLOC_METHOD_SKB);

	}