netdev - [PATCH bpf-next v2 2/5] i40e: remove unnecessary sw

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1605006094-31097-3-git-send-email-magnus.karlsson@gmail.com>
Date:   Tue, 10 Nov 2020 12:01:31 +0100
From:   Magnus Karlsson <magnus.karlsson@...il.com>
To:     magnus.karlsson@...el.com, bjorn.topel@...el.com, ast@...nel.org,
        daniel@...earbox.net, netdev@...r.kernel.org,
        jonathan.lemon@...il.com, kuba@...nel.org, john.fastabend@...il.com
Cc:     bpf@...r.kernel.org, jeffrey.t.kirsher@...el.com,
        anthony.l.nguyen@...el.com, maciej.fijalkowski@...el.com,
        maciejromanfijalkowski@...il.com, intel-wired-lan@...ts.osuosl.org
Subject: [PATCH bpf-next v2 2/5] i40e: remove unnecessary sw_ring access from xsk Tx

From: Magnus Karlsson <magnus.karlsson@...el.com>

Remove the unnecessary access to the software ring for the AF_XDP
zero-copy driver. This was used to record the length of the packet so
that the driver Tx completion code could sum this up to produce the
total bytes sent. This is now performed during the transmission of the
packet, so no need to record this in the software ring.

Signed-off-by: Magnus Karlsson <magnus.karlsson@...el.com>
Acked-by: John Fastabend <john.fastabend@...il.com>
---
 drivers/net/ethernet/intel/i40e/i40e_xsk.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
index 6acede0..61aa1fc 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
@@ -392,7 +392,6 @@ static bool i40e_xmit_zc(struct i40e_ring *xdp_ring, unsigned int budget)
 {
 	unsigned int sent_frames = 0, total_bytes = 0;
 	struct i40e_tx_desc *tx_desc = NULL;
-	struct i40e_tx_buffer *tx_bi;
 	struct xdp_desc desc;
 	dma_addr_t dma;
 
@@ -404,9 +403,6 @@ static bool i40e_xmit_zc(struct i40e_ring *xdp_ring, unsigned int budget)
 		xsk_buff_raw_dma_sync_for_device(xdp_ring->xsk_pool, dma,
 						 desc.len);
 
-		tx_bi = &xdp_ring->tx_bi[xdp_ring->next_to_use];
-		tx_bi->bytecount = desc.len;
-
 		tx_desc = I40E_TX_DESC(xdp_ring, xdp_ring->next_to_use);
 		tx_desc->buffer_addr = cpu_to_le64(dma);
 		tx_desc->cmd_type_offset_bsz =
@@ -415,7 +411,7 @@ static bool i40e_xmit_zc(struct i40e_ring *xdp_ring, unsigned int budget)
 				   0, desc.len, 0);
 
 		sent_frames++;
-		total_bytes += tx_bi->bytecount;
+		total_bytes += desc.len;
 
 		xdp_ring->next_to_use++;
 		if (xdp_ring->next_to_use == xdp_ring->count)
-- 
2.7.4