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Revision 1d5a474240407c38ca8c7484a656ee39f585399c authored by Martin Habets on 02 January 2022, 08:41:22 UTC, committed by Jakub Kicinski on 05 January 2022, 02:14:21 UTC 
sfc: The RX page_ring is optional
 
The RX page_ring is an optional feature that improves
performance. When allocation fails the driver can still
function, but possibly with a lower bandwidth.
Guard against dereferencing a NULL page_ring.

Fixes: 2768935a4660 ("sfc: reuse pages to avoid DMA mapping/unmapping costs")
Signed-off-by: Martin Habets <habetsm.xilinx@gmail.com>
Reported-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Link: https://lore.kernel.org/r/164111288276.5798.10330502993729113868.stgit@palantir17.mph.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
1 parent 6f89ecf
Raw File
tcp_dctcp.h 
#ifndef _TCP_DCTCP_H
#define _TCP_DCTCP_H

static inline void dctcp_ece_ack_cwr(struct sock *sk, u32 ce_state)
{
	struct tcp_sock *tp = tcp_sk(sk);

	if (ce_state == 1)
		tp->ecn_flags |= TCP_ECN_DEMAND_CWR;
	else
		tp->ecn_flags &= ~TCP_ECN_DEMAND_CWR;
}

/* Minimal DCTP CE state machine:
 *
 * S:	0 <- last pkt was non-CE
 *	1 <- last pkt was CE
 */
static inline void dctcp_ece_ack_update(struct sock *sk, enum tcp_ca_event evt,
					u32 *prior_rcv_nxt, u32 *ce_state)
{
	u32 new_ce_state = (evt == CA_EVENT_ECN_IS_CE) ? 1 : 0;

	if (*ce_state != new_ce_state) {
		/* CE state has changed, force an immediate ACK to
		 * reflect the new CE state. If an ACK was delayed,
		 * send that first to reflect the prior CE state.
		 */
		if (inet_csk(sk)->icsk_ack.pending & ICSK_ACK_TIMER) {
			dctcp_ece_ack_cwr(sk, *ce_state);
			__tcp_send_ack(sk, *prior_rcv_nxt);
		}
		inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_NOW;
	}
	*prior_rcv_nxt = tcp_sk(sk)->rcv_nxt;
	*ce_state = new_ce_state;
	dctcp_ece_ack_cwr(sk, new_ce_state);
}

#endif
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