On Wed, 2015-08-19 at 07:17 -0700, Eric Dumazet wrote:

On Wed, 2015-08-19 at 15:59 +0300, Emmanuel Grumbach wrote:

quoted

The segmentation is done completely in software. The
driver creates several MPDUs out of a single large send.
Each MPDU is a newly allocated SKB.
A page is allocated to create the headers that need to be
duplicated (SNAP / IP / TCP). The WiFi header is in the
header of the newly created SKBs.

type=feature

Change-Id: I238ffa79cacc5bbdacdfbf3e9673c8d4f02b462a
Signed-off-by: Emmanuel Grumbach <redacted>
---
 drivers/net/wireless/iwlwifi/mvm/tx.c | 513 +++++++++++++++++++++++++++++++---
 1 file changed, 481 insertions(+), 32 deletions(-)

Ouch dynamic allocations while doing xmit are certainly not needed.
Your driver should pre-allocated space for headers.

Drivers willing to implement tso have to use net/core/tso.c provided
helpers.

$ git grep -n tso_build_hdr
drivers/net/ethernet/cavium/thunder/nicvf_queues.c:1030:                tso_build_hdr(skb, hdr, &tso, data_left, total_len == 0);
drivers/net/ethernet/freescale/fec_main.c:729:          tso_build_hdr(skb, hdr, &tso, data_left, total_len == 0);
drivers/net/ethernet/marvell/mv643xx_eth.c:842:         tso_build_hdr(skb, hdr, &tso, data_left, total_len == 0);
drivers/net/ethernet/marvell/mvneta.c:1650:             tso_build_hdr(skb, hdr, &tso, data_left, total_len == 0);
include/net/tso.h:15:void tso_build_hdr(struct sk_buff *skb, char *hdr, struct tso_t *tso,
net/core/tso.c:14:void tso_build_hdr(struct sk_buff *skb, char *hdr, struct tso_t *tso,
net/core/tso.c:37:EXPORT_SYMBOL(tso_build_hdr);

Look at commit 2adb719d74f6e174071e5c913290b9bbd8c2c0e8 for a typical
use of these helpers.


--
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html