Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted

Pull I3C updates from Alexandre Belloni:
 "A new driver this cycle, for the AMD AXI I3C controller.

  There are also new features such as IBI wakeup support, SETAASA device
  discovery and ACPI support for the the DAA methods, meaning we can now
  communicate with the SPD devices on DDR5 modules.

  New driver:
   - AMD AXI I3C master controller

  Subsystem:
   - I3C Common Command Code (CCC) handling improvements, especially
     around GET CCCs
   - SETAASA device discovery support
   - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
     well as I2C devices on I3C bus
   - IBI-based wakeup support

  Drivers:
   - dw: SETAASA support
   - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
     controller support, PIO queue management support for HCI v1.2
   - renesas: improve suspend to RAM support, add runtime PM support"

* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
  i3c: dw: reduce do_daa time if there's no client
  i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
  i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
  i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
  i3c: dw: rename "pclk" to "apb" to match dt-binding
  i3c: dw: make struct dw_i3c_cmd smaller
  i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
  i3c: renesas: Don't register devices when ENTDAA times out
  i3c: master: dw-i3c-master: fix OD timing for first broadcast
  i3c: mipi-i3c-hci: Advertise IBI wakeup capability
  i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
  i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
  i3c: master: Reject IBI requests from non-IBI-capable devices
  i3c: master: Add helper to query bus wakeup requirements
  i3c: master: Report wakeup events for IBIs
  i3c: master: Support IBI-based wakeup capability
  i3c: master: Fix potential UAF in i3c_device_match()
  i3c: master: Fix potential UAF in i3c_device_uevent()
  i3c: Make dev->desc locking assumptions explicit
  i3c: master: Fix use-after-free of master->this
  ...

1 files changed, 241 insertions, 0 deletions

diff --git a/net/ipv4/tcp_yeah.c b/net/ipv4/tcp_yeah.c
new file mode 100644
index 000000000..9e581154f
--- /dev/null
+++ b/net/ipv4/tcp_yeah.c
@@ -0,0 +1,241 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *
+ *   YeAH TCP
+ *
+ * For further details look at:
+ *   https://web.archive.org/web/20080316215752/http://wil.cs.caltech.edu/pfldnet2007/paper/YeAH_TCP.pdf
+ *
+ */
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/inet_diag.h>
+
+#include <net/tcp.h>
+
+#include "tcp_vegas.h"
+
+#define TCP_YEAH_ALPHA       80 /* number of packets queued at the bottleneck */
+#define TCP_YEAH_GAMMA        1 /* fraction of queue to be removed per rtt */
+#define TCP_YEAH_DELTA        3 /* log minimum fraction of cwnd to be removed on loss */
+#define TCP_YEAH_EPSILON      1 /* log maximum fraction to be removed on early decongestion */
+#define TCP_YEAH_PHY          8 /* maximum delta from base */
+#define TCP_YEAH_RHO         16 /* minimum number of consecutive rtt to consider competition on loss */
+#define TCP_YEAH_ZETA        50 /* minimum number of state switches to reset reno_count */
+
+#define TCP_SCALABLE_AI_CNT	 100U
+
+/* YeAH variables */
+struct yeah {
+	struct vegas vegas;	/* must be first */
+
+	/* YeAH */
+	u32 lastQ;
+	u32 doing_reno_now;
+
+	u32 reno_count;
+	u32 fast_count;
+};
+
+static void tcp_yeah_init(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct yeah *yeah = inet_csk_ca(sk);
+
+	tcp_vegas_init(sk);
+
+	yeah->doing_reno_now = 0;
+	yeah->lastQ = 0;
+
+	yeah->reno_count = 2;
+
+	/* Ensure the MD arithmetic works.  This is somewhat pedantic,
+	 * since I don't think we will see a cwnd this large. :) */
+	tp->snd_cwnd_clamp = min_t(u32, tp->snd_cwnd_clamp, 0xffffffff/128);
+}
+
+static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack, u32 acked)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct yeah *yeah = inet_csk_ca(sk);
+
+	if (!tcp_is_cwnd_limited(sk))
+		return;
+
+	if (tcp_in_slow_start(tp)) {
+		acked = tcp_slow_start(tp, acked);
+		if (!acked)
+			goto do_vegas;
+	}
+
+	if (!yeah->doing_reno_now) {
+		/* Scalable */
+		tcp_cong_avoid_ai(tp, min(tcp_snd_cwnd(tp), TCP_SCALABLE_AI_CNT),
+				  acked);
+	} else {
+		/* Reno */
+		tcp_cong_avoid_ai(tp, tcp_snd_cwnd(tp), acked);
+	}
+
+	/* The key players are v_vegas.beg_snd_una and v_beg_snd_nxt.
+	 *
+	 * These are so named because they represent the approximate values
+	 * of snd_una and snd_nxt at the beginning of the current RTT. More
+	 * precisely, they represent the amount of data sent during the RTT.
+	 * At the end of the RTT, when we receive an ACK for v_beg_snd_nxt,
+	 * we will calculate that (v_beg_snd_nxt - v_vegas.beg_snd_una) outstanding
+	 * bytes of data have been ACKed during the course of the RTT, giving
+	 * an "actual" rate of:
+	 *
+	 *     (v_beg_snd_nxt - v_vegas.beg_snd_una) / (rtt duration)
+	 *
+	 * Unfortunately, v_vegas.beg_snd_una is not exactly equal to snd_una,
+	 * because delayed ACKs can cover more than one segment, so they
+	 * don't line up yeahly with the boundaries of RTTs.
+	 *
+	 * Another unfortunate fact of life is that delayed ACKs delay the
+	 * advance of the left edge of our send window, so that the number
+	 * of bytes we send in an RTT is often less than our cwnd will allow.
+	 * So we keep track of our cwnd separately, in v_beg_snd_cwnd.
+	 */
+do_vegas:
+	if (after(ack, yeah->vegas.beg_snd_nxt)) {
+		/* We do the Vegas calculations only if we got enough RTT
+		 * samples that we can be reasonably sure that we got
+		 * at least one RTT sample that wasn't from a delayed ACK.
+		 * If we only had 2 samples total,
+		 * then that means we're getting only 1 ACK per RTT, which
+		 * means they're almost certainly delayed ACKs.
+		 * If  we have 3 samples, we should be OK.
+		 */
+
+		if (yeah->vegas.cntRTT > 2) {
+			u32 rtt, queue;
+			u64 bw;
+
+			/* We have enough RTT samples, so, using the Vegas
+			 * algorithm, we determine if we should increase or
+			 * decrease cwnd, and by how much.
+			 */
+
+			/* Pluck out the RTT we are using for the Vegas
+			 * calculations. This is the min RTT seen during the
+			 * last RTT. Taking the min filters out the effects
+			 * of delayed ACKs, at the cost of noticing congestion
+			 * a bit later.
+			 */
+			rtt = yeah->vegas.minRTT;
+
+			/* Compute excess number of packets above bandwidth
+			 * Avoid doing full 64 bit divide.
+			 */
+			bw = tcp_snd_cwnd(tp);
+			bw *= rtt - yeah->vegas.baseRTT;
+			do_div(bw, rtt);
+			queue = bw;
+
+			if (queue > TCP_YEAH_ALPHA ||
+			    rtt - yeah->vegas.baseRTT > (yeah->vegas.baseRTT / TCP_YEAH_PHY)) {
+				if (queue > TCP_YEAH_ALPHA &&
+				    tcp_snd_cwnd(tp) > yeah->reno_count) {
+					u32 reduction = min(queue / TCP_YEAH_GAMMA ,
+							    tcp_snd_cwnd(tp) >> TCP_YEAH_EPSILON);
+
+					tcp_snd_cwnd_set(tp, tcp_snd_cwnd(tp) - reduction);
+
+					tcp_snd_cwnd_set(tp, max(tcp_snd_cwnd(tp),
+								 yeah->reno_count));
+
+					WRITE_ONCE(tp->snd_ssthresh,
+						   tcp_snd_cwnd(tp));
+				}
+
+				if (yeah->reno_count <= 2)
+					yeah->reno_count = max(tcp_snd_cwnd(tp)>>1, 2U);
+				else
+					yeah->reno_count++;
+
+				yeah->doing_reno_now = min(yeah->doing_reno_now + 1,
+							   0xffffffU);
+			} else {
+				yeah->fast_count++;
+
+				if (yeah->fast_count > TCP_YEAH_ZETA) {
+					yeah->reno_count = 2;
+					yeah->fast_count = 0;
+				}
+
+				yeah->doing_reno_now = 0;
+			}
+
+			yeah->lastQ = queue;
+		}
+
+		/* Save the extent of the current window so we can use this
+		 * at the end of the next RTT.
+		 */
+		yeah->vegas.beg_snd_una  = yeah->vegas.beg_snd_nxt;
+		yeah->vegas.beg_snd_nxt  = tp->snd_nxt;
+		yeah->vegas.beg_snd_cwnd = tcp_snd_cwnd(tp);
+
+		/* Wipe the slate clean for the next RTT. */
+		yeah->vegas.cntRTT = 0;
+		yeah->vegas.minRTT = 0x7fffffff;
+	}
+}
+
+static u32 tcp_yeah_ssthresh(struct sock *sk)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	struct yeah *yeah = inet_csk_ca(sk);
+	u32 reduction;
+
+	if (yeah->doing_reno_now < TCP_YEAH_RHO) {
+		reduction = yeah->lastQ;
+
+		reduction = min(reduction, max(tcp_snd_cwnd(tp)>>1, 2U));
+
+		reduction = max(reduction, tcp_snd_cwnd(tp) >> TCP_YEAH_DELTA);
+	} else
+		reduction = max(tcp_snd_cwnd(tp)>>1, 2U);
+
+	yeah->fast_count = 0;
+	yeah->reno_count = max(yeah->reno_count>>1, 2U);
+
+	return max_t(int, tcp_snd_cwnd(tp) - reduction, 2);
+}
+
+static struct tcp_congestion_ops tcp_yeah __read_mostly = {
+	.init		= tcp_yeah_init,
+	.ssthresh	= tcp_yeah_ssthresh,
+	.undo_cwnd      = tcp_reno_undo_cwnd,
+	.cong_avoid	= tcp_yeah_cong_avoid,
+	.set_state	= tcp_vegas_state,
+	.cwnd_event	= tcp_vegas_cwnd_event,
+	.cwnd_event_tx_start = tcp_vegas_cwnd_event_tx_start,
+	.get_info	= tcp_vegas_get_info,
+	.pkts_acked	= tcp_vegas_pkts_acked,
+
+	.owner		= THIS_MODULE,
+	.name		= "yeah",
+};
+
+static int __init tcp_yeah_register(void)
+{
+	BUILD_BUG_ON(sizeof(struct yeah) > ICSK_CA_PRIV_SIZE);
+	tcp_register_congestion_control(&tcp_yeah);
+	return 0;
+}
+
+static void __exit tcp_yeah_unregister(void)
+{
+	tcp_unregister_congestion_control(&tcp_yeah);
+}
+
+module_init(tcp_yeah_register);
+module_exit(tcp_yeah_unregister);
+
+MODULE_AUTHOR("Angelo P. Castellani");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("YeAH TCP");